WorldWideScience

Sample records for aespoe hard rock

  1. Aespoe hard rock laboratory Sweden

    International Nuclear Information System (INIS)

    The aim of the new Aespoe hard rock laboratory is to demonstrate state of the art of technology and evaluation methods before the start of actual construction work on the planned deep repository for spent nuclear fuel. The nine country OECD/NEA project in the Stripa mine in Sweden has been an excellent example of high quality international research co-operation. In Sweden the new Aespoe hard rock laboratory will gradually take over and finalize this work. SKB very much appreciates the continued international participation in Aespoe which is of great value for the quality efficiency, and confidence in this kind of work. We have invited a number of leading experts to this first international seminar to summarize the current state of a number of key questions. The contributions show the great progress that has taken place during the years. The results show that there is a solid scientific basis for using this knowledge on site specific preparation and work on actual repositories. (au)

  2. Aespoe hard rock laboratory. Annual report 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  3. Aespoe hard rock laboratory. Annual report 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  4. Aespoe Hard Rock Laboratory. Annual Report 2011

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-03-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below.

  5. Aespoe Hard Rock Laboratory. Annual Report 2011

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below

  6. Aespoe Hard Rock Laboratory. Annual Report 1993

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is being constructed in preparation for the deep geological repository of spent fuel in Sweden. This Annual Report 1993 for the Aespoe Hard Rock Laboratory contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of the detailed investigation methodology. Construction of the facility and investigation of the bedrock are carried out in parallel. As of December 1993, 2760 m of the tunnel had been excavated to a depth of 370 m below the surface. An important and integral part of the work is further refinement of conceptual and numerical models for groundwater flow and radionuclide migration. Detailed plans have been prepared for several experiments to be conducted after the end of the construction work. Eight organizations from seven countries are now participating in the work at the Aespoe Hard Rock Laboratory and are contributing in different ways to the results being achieved

  7. Aespoe Hard Rock Laboratory. Annual Report 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation.

  8. Aespoe Hard Rock Laboratory. Annual Report 2006

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation

  9. Aespoe Hard Rock Laboratory Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework.

  10. Aespoe Hard Rock Laboratory Annual report 2003

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework

  11. Aespoe hard rock laboratory. Annual report 1992

    International Nuclear Information System (INIS)

    The Aespoe hard rock laboratory is being constructed in preparation for the deep geological repository of spent fuel in Sweden. This Annual report 1992 for the Aespoe hard rock laboratory contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of the detailed investigation methodology. Construction of the facility and investigation of the bedrock are being carried out in parallel. December 1992 1925 m of the tunnel has been excavated to a depth of 255 m below surface. An important and integrated part of the work is further refinement of conceptual and numerical models for groundwater flow and radionuclide migration. This work is carried out in cooperation with seven organizations from six countries that participate in the project. (25 refs.)

  12. Aespoe Hard Rock Laboratory. Annual Report 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL, experiments are

  13. Aespoe Hard Rock Laboratory. Annual Report 2001

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported during 2001

  14. Aespoe Hard Rock Laboratory. Annual Report 2005

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the

  15. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important

  16. Aespoe Hard Rock Laboratory. Annual Report 2008

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative Buffer

  17. Aespoe Hard Rock Laboratory. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported

  18. Aespoe Hard Rock Laboratory. Annual Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL

  19. Aespoe Hard Rock Laboratory. Annual report 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using {sup 57}Co, {sup 114}Cs,{sup 85}Sr, {sup 99}Tc, and {sup 131}I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The

  20. Aespoe Hard Rock Laboratory. Annual report 1997

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using 57Co, 114Cs,85Sr, 99Tc, and 131I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at

  1. Aespoe Hard Rock Laboratory. Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative

  2. Aespoe Hard Rock Laboratory Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  3. Aespoe Hard Rock Laboratory Annual Report 1999

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  4. Experiments at the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    A dress rehearsal is being held in preparation for the construction of a deep repository for spent nuclear fuel at SKB's underground Hard Rock Laboratory (HRL) on Aespoe, outside Oskarshamn. Here we can test different technical solutions on a full scale and in a realistic environment. The Aespoe HRL is also used for field research. We are conducting a number of experiments here in collaboration with Swedish and international experts. In the Zedex experiment we have compared how the rock is affected around a drill-and-blast tunnel versus a bored tunnel. In a new experiment we will investigate how much the rock can take. A narrow pillar between two boreholes will be loaded to the point that the rock's ultimate strength is exceeded (Aespoe Pillar Stability Experiment). In the Demo Test we are demonstrating emplacement of the copper canisters and the surrounding bentonite in the deposition holes. In the Prototype Repository we study what long-term changes occur in the barriers under the conditions prevailing in a deep repository. Horizontal deposition: Is it possible to deposit the canisters horizontally without compromising safety? Backfill and Plug Test: The tunnels in the future deep repository for spent nuclear fuel will be filled with clay and crushed rock and then plugged. Canister Retrieval Test: If the deep repository should not perform satisfactorily for some reason, we want to be able to retrieve the spent fuel. The Lot test is intended to show how the bentonite behaves in an environment similar to that in the future deep repository. The purpose of the TBT test is to determine how the bentonite clay in the buffer is affected by high temperatures. Two-phase flow means that liberated gas in the groundwater flows separately in the fractures in the rock. This reduces the capacity of the rock to conduct water. Lasgit: By pressurizing a canister with helium, we can measure how the gas moves through the surrounding buffer. Colloid Project: Can very small particles

  5. Aespoe hard rock laboratory. Annual report 2000

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of the

  6. Aespoe Hard Rock Laboratory. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  7. Aespoe Hard Rock Laboratory. Annual report 1998

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  8. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009

  9. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  10. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  11. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  12. Aespoe Hard Rock Laboratory. Status Report January - April 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2009

  13. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010

  14. Aespoe Hard Rock Laboratory Annual Report 1994

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is being constructed as part of the preparations for the deep geological repository of spent nuclear fuel in Sweden. The annual report 1994 contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of detailed investigation methodology which is applied during tunnel construction. Construction of the facility and detailed characterization of the bedrock are performed in parallel. Excavation of the main access tunnel was completed during 1994 and at the end of the year only minor excavation work remained. The last 400 m of the main tunnel, which has a total length of 3600 m, was excavated by a 5 m diameter boring machine. The tunnel reaches a depth of 450 m below ground. Preparations for the operating phase have started and detailed plans have been prepared for several experiments. Nine organizations, including SKB, from eight countries are now participating in the work at the laboratory. 50 refs, 28 figs

  15. Aespoe hard rock laboratory. Annual report 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of

  16. Aespoe Hard Rock Laboratory. Annual Report 2007

    International Nuclear Information System (INIS)

    The main activities in the geoscientific fields have been: (1) Geology - besides mapping of rock surfaces and drill cores a feasibility study concerning geological mapping techniques is performed, (2) Hydrogeology - completion of the modelling work for the detailed hydro-structural model for the -450 m level and monitoring/storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field work to determine the stress levels at which core disking occur followed by numerical modelling. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The experiments are related to the rock, its properties and in situ environmental conditions. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. An important goal is to demonstrate technology for and the function of important parts of the repository system. This implies translation of current scientific knowledge and state-of- the-art technology into engineering practice applicable in a real repository. It is important that development, testing and demonstration of methods and procedures are conducted under realistic conditions and at an appropriate scale. A number of large-scale field

  17. AeSPoe HARD ROCK LABORATORY

    International Nuclear Information System (INIS)

    Aespoe Hard Rock Laboratory (AEHRL) has been constructed in virgin bedrock as part of the development of a deep geological repository for spent nuclear fuel in Sweden, the role being to provide input to the performance assessment, to test engineered barrier systems and to develop and refine full scale methods and machines for construction and operation of the real repository. The AEHRL extends down to 460 m depth with access via both ramp and shaft. Work in the laboratory has been separated into 4 different stage goals: (1) Verification of site investigation methods. (2) Development of detailed investigation methodology. (3) Testing of models for description of the barrier function of the host rock. (4) Demonstration of technology for and function of important parts of the repository system Stage goals 1 and 2 were in focus during the period 1986-95 and are now completed. Stage goal 1 concerns investigations carried out from ground surface and stage goal 2 investigations carried out underground, in this case during excavation of the ramp. The present work is focused on the two operative stage goals 3 and 4. The activities on barrier function of the host rock comprises primarily in-situ tests with tracer migration in natural fractures and migration of actinides in small samples of rock or bentonite inside a chemical laboratory probe installed in a borehole. The data collected from the tests are used for model development and verification. The demonstration of technology includes studies of engineered barriers and comprises tests of copper stability, bentonite buffer, backfill, plugging and practical development of the main disposal sequences. Up today five full scale deposition holes with buffer and canister, and one full-scale test of backfill and plugging have been installed. The prototype for the deposition machine is in operation. The work is conducted in an international environment and altogether eight organizations from seven countries besides Sweden take

  18. Aespoe Hard Rock Laboratory Annual Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    At Aespoe HRL, methods for characterising a suitable site for a deep repository are being developed and tested. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995. Most of the research is focused on processes of importance for the long-term safety of a future deep repository. To meet the overall time schedule for SKB's RDandD work, the following stage goals were initially defined for the work at the Aespoe HRL. 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop and at repository depth test methods and models for description of groundwater flow, radionuclide migration, and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the repository system. Test, investigate and demonstrate on full-scale different components of importance for the long-term safety of a deep repository and to show that high quality can be achieved in design, construction, and operation of repository components. Stage goals 1 and 2 have been concluded at Aespoe HRL and the tasks have been transferred to the Site Investigation Department of SKB which performs site investigations at two sites, Simpevarp/Laxemar in the municipality of Oskarshamn and Forsmark in the municipality of Oesthammar. In order to reach present goals the following important tasks are performed at the Aespoe HRL: Develop, test, evaluate and

  19. Aespoe Hard Rock Laboratory Annual Report 2004

    International Nuclear Information System (INIS)

    At Aespoe HRL, methods for characterising a suitable site for a deep repository are being developed and tested. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995. Most of the research is focused on processes of importance for the long-term safety of a future deep repository. To meet the overall time schedule for SKB's RDandD work, the following stage goals were initially defined for the work at the Aespoe HRL. 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop and at repository depth test methods and models for description of groundwater flow, radionuclide migration, and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the repository system. Test, investigate and demonstrate on full-scale different components of importance for the long-term safety of a deep repository and to show that high quality can be achieved in design, construction, and operation of repository components. Stage goals 1 and 2 have been concluded at Aespoe HRL and the tasks have been transferred to the Site Investigation Department of SKB which performs site investigations at two sites, Simpevarp/Laxemar in the municipality of Oskarshamn and Forsmark in the municipality of Oesthammar. In order to reach present goals the following important tasks are performed at the Aespoe HRL: Develop, test, evaluate and demonstrate

  20. Aespoe Hard Rock Laboratory. Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-04-15

    The main activities in the geoscientific fields have been: (1) Geology - besides mapping of rock surfaces and drill cores a feasibility study concerning geological mapping techniques is performed, (2) Hydrogeology - completion of the modelling work for the detailed hydro-structural model for the -450 m level and monitoring/storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field work to determine the stress levels at which core disking occur followed by numerical modelling. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The experiments are related to the rock, its properties and in situ environmental conditions. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. An important goal is to demonstrate technology for and the function of important parts of the repository system. This implies translation of current scientific knowledge and state-of- the-art technology into engineering practice applicable in a real repository. It is important that development, testing and demonstration of methods and procedures are conducted under realistic conditions and at an appropriate scale. A number of large-scale field

  1. Aespoe Hard Rock Laboratory. Annual Report 2002

    International Nuclear Information System (INIS)

    The Aespoe HRL was opened in 1994 as a research centre and underground laboratory. The experiments performed in Aespoe HRL are related to the rock, its properties, and in situ environmental conditions. Tests of models for groundwater flow, radionuclide migration and chemical/biological processes are some of the main purposes of the Aespoe HRL. The programme includes projects with the aim to evaluate the usefulness and reliability of different models and to develop and test methods for determination of parameters required as input to conceptual and numerical models. The retardation in rock is studied at different experiment scales in a programme called Tracer Retention Understanding Experiments (TRUE). The Long Term Diffusion Experiment constitutes a complement to performed diffusion and sorption laboratory experiments, and is a natural extension of the experiments conducted as part of the TRUE experiments. Radionuclide retention experiments are carried out with the aim to confirm result from laboratory experiments in situ, where conditions representative for the properties of groundwater at repository depth prevail. In CHEMLAB 1 two kinds of experiments to study the influence of radiolysis on the mobility of technetium in bentonite were started in the end of 2002. Experiments to study migration of actinides in natural fractures in drill cores are being carried out in CHELMAB 2. The findings of potential transport of solutes by colloids and access to more sensitive instruments for colloid measurements motivated a Colloid Project at Aespoe HRL. There are presently four specific microbial process areas identified that are of importance for proper repository functions and that are studied in the Microbe Project. The process areas are; biomobilisation of radionuclides, bioimmobilisation of radionuclides, microbial effects on the chemical stability, and microbial corrosion of copper. The main objectives of the Matrix Fluid Chemistry experiment are to understand the

  2. Aespoe Hard Rock Laboratory. Annual report 1996

    International Nuclear Information System (INIS)

    The Aespoe HRL has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. Geoscientific investigations on Aespoe and nearby islands began 1986. Since then, bedrock conditions have been investigated by several deep boreholes. The Aespoe research village has been built and extensive underground construction work has been undertaken in parallel with comprehensive research. This has resulted in a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The objective of the ZEDEX project is to compare the mechanical disturbance to the rock for excavation by tunnel boring and blasting. The results indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The tracer retention understanding experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models. During 1996 a series of tracer experiments in radially converging and dipole flow configuration have been performed. A special borehole probe has been designed for different kinds of retention experiments where data can be obtained representative for the in situ properties of groundwater at repository depth. The prototype repository test is focused on testing and demonstrating repository system function, and includes backfill and plug tests and demonstration of methods for deposition and retrieval of canisters in a new tunnel at the 420 m level. The long term tests of buffer material aim to validate models of buffer performance and at quantifying clay buffer alteration processes at adverse conditions. 80 refs, 53 figs, 16 tabs

  3. Aespoe hard rock laboratory. Current research projects 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a `dress rehearsal` for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book `Aespoe Hard Rock Laboratory - 10 years of Research` published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

  4. Aespoe hard rock laboratory. Current research projects 1998

    International Nuclear Information System (INIS)

    In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a 'dress rehearsal' for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book 'Aespoe Hard Rock Laboratory - 10 years of Research' published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

  5. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The Aespoe HRL was opened in 1994 as a research centre and underground laboratory. The experiments performed in Aespoe HRL are related to the rock, its properties, and in situ environmental conditions. Tests of models for groundwater flow, radionuclide migration and chemical/biological processes are some of the main purposes of the Aespoe HRL. The programme includes projects with the aim to evaluate the usefulness and reliability of different models and to develop and test methods for determination of parameters required as input to conceptual and numerical models. The retardation in rock is studied at different experiment scales in a programme called Tracer Retention Understanding Experiments (TRUE). The Long Term Diffusion Experiment constitutes a complement to performed diffusion and sorption laboratory experiments, and is a natural extension of the experiments conducted as part of the TRUE experiments. Radionuclide retention experiments are carried out with the aim to confirm result from laboratory experiments in situ, where conditions representative for the properties of groundwater at repository depth prevail. In CHEMLAB 1 two kinds of experiments to study the influence of radiolysis on the mobility of technetium in bentonite were started in the end of 2002. Experiments to study migration of actinides in natural fractures in drill cores are being carried out in CHELMAB 2. The findings of potential transport of solutes by colloids and access to more sensitive instruments for colloid measurements motivated a Colloid Project at Aespoe HRL. There are presently four specific microbial process areas identified that are of importance for proper repository functions and that are studied in the Microbe Project. The process areas are; biomobilisation of radionuclides, bioimmobilisation of radionuclides, microbial effects on the chemical stability, and microbial corrosion of copper. The main objectives of the Matrix Fluid Chemistry experiment are to understand the

  6. Aespoe Hard Rock Laboratory. Status Report October - December 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-03-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the fourth quarter of 2008.

  7. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  8. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  9. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010.

  10. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  11. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-11-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009.

  12. Aespoe Hard Rock Laboratory. Status Report January - April 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-09-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2009.

  13. Aespoe Hard Rock Laboratory. Status Report. July - September 2008

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the third quarter of 2008.

  14. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  15. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The Aespoe HRL was opened in 1994 as a research centre and underground laboratory. The experiments performed in Aespoe HRL are related to the rock, its properties, and in situ environmental conditions. Tests of models for groundwater flow, radionuclide migration and chemical/biological processes are some of the main purposes of the Aespoe HRL. The programme includes projects with the aim to evaluate the usefulness and reliability of different models and to develop and test methods for determination of parameters required as input to conceptual and numerical models. The retardation in rock is studied at different experiment scales in a programme called Tracer Retention Understanding Experiments (TRUE). The Long Term Diffusion Experiment constitutes a complement to performed diffusion and sorption laboratory experiments, and is a natural extension of the experiments conducted as part of the TRUE experiments. Radionuclide retention experiments are carried out with the aim to confirm result from laboratory experiments in situ, where conditions representative for the properties of groundwater at repository depth prevail. In CHEMLAB 1 two kinds of experiments to study the influence of radiolysis on the mobility of technetium in bentonite were started in the end of 2002. Experiments to study migration of actinides in natural fractures in drill cores are being carried out in CHELMAB 2. The findings of potential transport of solutes by colloids and access to more sensitive instruments for colloid measurements motivated a Colloid Project at Aespoe HRL. There are presently four specific microbial process areas identified that are of importance for proper repository functions and that are studied in the Microbe Project. The process areas are; biomobilisation of radionuclides, bioimmobilisation of radionuclides, microbial effects on the chemical stability, and microbial corrosion of copper. The main objectives of the Matrix Fluid Chemistry experiment are to understand the

  16. Aespoe Hard Rock Laboratory. Planning Report for 2011

    International Nuclear Information System (INIS)

    This report presents the planned activities for the year 2011. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2010, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Background information on the projects is given in the Annual Report as well as findings and results

  17. Aespoe Hard Rock Laboratory. Annual Report 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The construction of the laboratory was completed during 1995 and the operating phase has now begun. During the construction data has been collected from the tunnel and boreholes drilled from the tunnel. Results from these investigations have been reported and a comprehensive evaluation is in progress. The results will be used to design the site characterization program for the deep repository. Ten organizations from nine countries participate in the work at the laboratory. An important part of the cooperative work is performed within the framework of the task force on groundwater flow and transport of solutes. An evaluation has been made of the long term pumping test which was performed at Aespoe some years ago. It showed that the modelling tools that exist today have the ability to give a three-dimensional description of groundwater flow at a site like Aespoe. The task force will perform predictive modelling of the tracer experiments performed within the TRUE project. Characterization of the experimental site for TRUE and preparations for the tracer tests were completed during 1995. Tests of the engineering barriers have been started with the test of technology for backfilling of deposition tunnels. 55 refs, 36 figs, 7 tabs.

  18. Aespoe Hard Rock Laboratory. Annual Report 1995

    International Nuclear Information System (INIS)

    The construction of the laboratory was completed during 1995 and the operating phase has now begun. During the construction data has been collected from the tunnel and boreholes drilled from the tunnel. Results from these investigations have been reported and a comprehensive evaluation is in progress. The results will be used to design the site characterization program for the deep repository. Ten organizations from nine countries participate in the work at the laboratory. An important part of the cooperative work is performed within the framework of the task force on groundwater flow and transport of solutes. An evaluation has been made of the long term pumping test which was performed at Aespoe some years ago. It showed that the modelling tools that exist today have the ability to give a three-dimensional description of groundwater flow at a site like Aespoe. The task force will perform predictive modelling of the tracer experiments performed within the TRUE project. Characterization of the experimental site for TRUE and preparations for the tracer tests were completed during 1995. Tests of the engineering barriers have been started with the test of technology for backfilling of deposition tunnels. 55 refs, 36 figs, 7 tabs

  19. Aespoe Hard Rock Laboratory. Planning Report for 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-15

    This report presents the planned activities for the year 2009. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results.

  20. Aespoe Hard Rock Laboratory. Planning Report for 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    This report presents the planned activities for the year 2010. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results

  1. Aespoe Hard Rock Laboratory. Planning Report for 2010

    International Nuclear Information System (INIS)

    This report presents the planned activities for the year 2010. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results

  2. Aespoe Hard Rock Laboratory. Planning Report for 2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    This report presents the planned activities for the year 2011. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2010, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Background information on the projects is given in the Annual Report as well as findings and results.

  3. Aespoe Hard Rock Laboratory. The TASS-tunnel. Geological mapping

    Energy Technology Data Exchange (ETDEWEB)

    Hardenby, Carljohan (Vattenfall Power Consultant AB (Sweden)); Sigurdsson, Oskar (HAskGeokonsult AB (Sweden))

    2010-12-15

    The project entitled 'Sealing of tunnel at great depth' (Fintaetning av tunnel paa stort djup) needed a new tunnel in an area as undisturbed as possible and with cross-cutting water-bearing structures. The new tunnel, which was given the name TASS, was excavated on the -450 m level of SKB's Aespoe Hard Rock Laboratory (Aespoe HRL). The length of the tunnel is approximately 80 m and the theoretical tunnel area 19 m2. As is the case with all the other tunnels of the Aespoe HRL, the new tunnel has been geologically mapped. In addition, laser scanning combined with digital photography has been carried out. The tunnel was also used to test various types of explosives, borehole layouts and drilling techniques. The geological mapping of tunnel floor, walls and roof took place on four major occasions when a halt was made in tunnel excavation to allow for various tests. Before the mapping started on these occasions, laser scanning took place. The tunnel faces were mapped after each round (drilling, blasting and unloading). The present report describes the geological features of the tunnel and briefly how the laser scanning was performed. Water-bearing structures have been compared to similar structures in the neighbouring tunnels. The rock type names used here follow the old established Aespoe HRL nomenclature. Narrow (<0.1 m wide) dykes are normally mapped as fracture fillings. The dominating rock type is Aespoe diorite, which constitutes some 90 % of the rock mass. It is mostly mapped as fresh rock. . Minor constituents of the rock mass are fine-grained granite, hybrid rock, pegmatite, quartz veins/lenses and undifferentiated mafic rock. The mapping of fractures and deformation zones considers a number of parameters such as number of fractures, open/healed, width, length, description of fracture surfaces (roughness, planarity, etc), fracture filling, alteration and water. The deformation zones are discriminated into two main categories (&apos

  4. Aespoe Hard Rock Laboratory. The TASS-tunnel. Geological mapping

    International Nuclear Information System (INIS)

    The project entitled 'Sealing of tunnel at great depth' (Fintaetning av tunnel paa stort djup) needed a new tunnel in an area as undisturbed as possible and with cross-cutting water-bearing structures. The new tunnel, which was given the name TASS, was excavated on the -450 m level of SKB's Aespoe Hard Rock Laboratory (Aespoe HRL). The length of the tunnel is approximately 80 m and the theoretical tunnel area 19 m2. As is the case with all the other tunnels of the Aespoe HRL, the new tunnel has been geologically mapped. In addition, laser scanning combined with digital photography has been carried out. The tunnel was also used to test various types of explosives, borehole layouts and drilling techniques. The geological mapping of tunnel floor, walls and roof took place on four major occasions when a halt was made in tunnel excavation to allow for various tests. Before the mapping started on these occasions, laser scanning took place. The tunnel faces were mapped after each round (drilling, blasting and unloading). The present report describes the geological features of the tunnel and briefly how the laser scanning was performed. Water-bearing structures have been compared to similar structures in the neighbouring tunnels. The rock type names used here follow the old established Aespoe HRL nomenclature. Narrow (<0.1 m wide) dykes are normally mapped as fracture fillings. The dominating rock type is Aespoe diorite, which constitutes some 90 % of the rock mass. It is mostly mapped as fresh rock. . Minor constituents of the rock mass are fine-grained granite, hybrid rock, pegmatite, quartz veins/lenses and undifferentiated mafic rock. The mapping of fractures and deformation zones considers a number of parameters such as number of fractures, open/healed, width, length, description of fracture surfaces (roughness, planarity, etc), fracture filling, alteration and water. The deformation zones are discriminated into two main categories ('increased fracturing' and

  5. Direct fault dating trials at the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    Over seventy rock samples were collected from fault and fracture zones in the Aespoe Hard Rock Laboratory tunnel for a study of direct fault dating techniques. Following microstructural and mineralogical analysis, isotopic, palaeomagnetic and electron spin resonance (ESR) methods were employed in an attempt to determine the age of the most recent movements on the sampled faults. The larger fracture zones contain faultrock assemblages and microstructures which are consistent with a prolonged and polyphase movement history, although the cumulative displacements involved formation of fault gouge cemented by authigenic 'illite'. Dating studies were targeted particularly at the gouge but also at older fault rock and vein phases. ESR dating of quartz graines, separated from gouge from fracture zones NE-4 and NE-3, strongly indicates that the ESR signals have not been reset by fault movements for a minimum time period of several hundred thousand to one million years. Palaeomagnetic dating of gouge from fracture zone NE-4 shows that a stable component of magnetisation overlaps both Precambrian and Permo-Triassic parts of the apparent polar wander curve. The younger age of magnetisation is preferred on geological grounds and by comparison with the isotopic dating results. The magnetisation may correspond to a diagenetic event following fault movement. Palaeomagnetic ages determined on countryrock and epidote vein samples are largely consistent with independent age constraints. K-Ar dating of clay fractions (<2 to <0.05μm) separated from gouge from four faults, including fracture zones NE-4 and NE-3, gave model ages in the range 706-301Ma. Accounting for the effects of contamination by potassium-bearing porphyroclasts, it is likely that authigenic 'illite' was formed at least 250 million years ago, after the most recent significant fault movements. 100 refs., 60 figs., 26 tabs

  6. Swedish hard rock laboratory. Evaluation of 1988 year preinvestigations and description of the target area, the island of Aespoe

    International Nuclear Information System (INIS)

    The site investigations for the Swedish Hard Rock Laboratory have been focussed on the southern part of the Aespoe island. Geological, geohydrological and chemical investigations have been made in three deep boreholes on Aespoe. The results are used to evaluate previous predictions of the properties of the rock mass and to set up new predictions, more detailed than the previous ones. At the southern part of Aespoe a basic rock type called the Aespoe diorite dominates at the depths of 300-600 m. The hydraulic conducticity is lower here than in the surrounding Smaaland Granite. The groundwater chemistry in contact with the Aespoe Diorite has a high iron content. The methods and techniques used for the investigations have been optimized and integrated. During the drilling operation both hydraulic tests and groundwater sampling were performed. (authors)

  7. Treatment and final disposal of nuclear waste. Aespoe hard rock laboratory

    International Nuclear Information System (INIS)

    The scientific investigations within SBK's research programme are a part of the work of designing a deep repository and identifying and investigating a suitable site. A balanced appraisal of the facts, requirements and assessments presented in connection with the preparation of R and D-programme 86 led to the proposal to construct an underground research laboratory. This proposal was presented in the aforementioned research programme and was very positively recived by the reviewing bodies. In the autumn of 1986, SKB initiated the field work for the siting of an underground laboratory, the Aespoe hard rock laboratory, in the Simpevarp area in the municipality of Oskarshamn. At the end of 1988, SKB arrived at a decision in principle to site the facility on southern Aespoe about 2 km north of the Oskarshamn nuclear power station. After regulatory review, SKB ordered the excavation of the access tunnel to the Aespoe hard rock laboratory to commence in the autumn of 1990. In conjunction with the tunneling work, which has now (September 1992) reached a depth of more than 200 m, a large number of investigations have been carried out. This background report to SKB's RD and D-programme 92 is based on the previous and 89 /2/. The report provides a general background and presents goals, projects results obtained to date and future work. Compared to the previous background reports, more space is devoted here to experiment planning and the future demonstration programme. (au)

  8. Experience gained from the site characterisation strategy used at the Aespoe hard rock laboratory

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is a 'dress-rehearsal' facility to test, develop and demonstrate technology and models prior to applications at the actual deep repository site in Sweden. Site characterisation methodology has for more than a decade been a main issue at the Aespoe Hard Rock Laboratory (HRL). At the start of site investigations in 1987 the following strategy was adopted: Comprehensive surface and surface-based investigations; Multi-disciplinary data collection in batches; Staged integrated evaluations on selected key issues closely tied to existing knowledge of the geology of the site; Iterative modelling on several geometrical scales based on existing (scarce) data; 'Predictive approach' to model updating. During the construction phase of the Aespoe HRL (1990 - 1995), a multitude of data was collected to test and to increase the details of the models made prior to construction. Several things have been learned regarding the appropriateness of the adopted approach to site characterisation. These findings concern e.g. data collection methods from surface and underground, construction/test-integration, choice of useful and feasible model concepts, data flow and document management. The acquired understanding, knowledge, skill and know-how are very valuable for planning useful and feasible site characterisation for the deep repository in Sweden

  9. Aespoe Hard Rock Laboratory. Overview of the investigations 1986-1990

    International Nuclear Information System (INIS)

    In order to prepare for the siting and licensing of a spent fuel repository SKB has decided to construct a new underground research laboratory. The pre-investigations for the Aespoe Hard Rock Laboratory started in late 1986. This report gives a comprehensive compilation of the different investigations performed during the pre-investigation phase (1986-1990). The information is mainly compiled in CAD-generated maps and illustrations in which the reader can gather information concerning the scope of work as well as references to more detailed reports for further study. (au)

  10. The colloid investigations conducted at the Aespoe Hard Rock Laboratory during 2000-2004

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus [Geopoint AB, Stockholm (Sweden); Wold, Susanna [Royal Inst. of Tech., Stockholm (Sweden). School of Chemical Science and Engineering, Nuclear Chemistry] (eds.)

    2005-12-15

    In 2000, SKB decided to initiate an international colloid project at the Aespoe Hard Rock Laboratory in Sweden. The objectives of the colloid project are to: (i) study the role of bentonite as a colloid source, (ii) verify the background colloid concentration at Aespoe HRL and, (iii) investigate the potential for colloid formation/transport in natural groundwater concentrations. The experimental concepts for the colloid project are: laboratory experiments with bentonite, background field measurements of natural colloids, borehole specific bentonite colloid stability experiments and a fracture specific transport experiment. The activities concerning the laboratory experiments and background field measurements are described in this work; the other activities are ongoing or planned. The following conclusions were made: The bentonite colloid stability is strongly dependent on the groundwater ionic strength. Natural colloids are organic degradation products such as humic and fulvic acids, inorganic colloids (clay, calcite, iron hydroxide) and microbes. Microbes form few but large particles and their concentration increase with increasing organic carbon concentrations. The small organic colloids are present in very low concentrations in deep granitic groundwater. The concentrations can be rather high in shallow waters. The colloid concentration decreases with depth and salinity, since colloids are less stable in saline waters. The colloid content at Aespoe is less than 300 ppb. The colloid content at repository level is less than 50 ppb. The groundwater variability obtained in the boreholes reflects well the natural groundwater variability along the whole HRL tunnel.

  11. The colloid investigations conducted at the Aespoe Hard Rock Laboratory during 2000-2004

    International Nuclear Information System (INIS)

    In 2000, SKB decided to initiate an international colloid project at the Aespoe Hard Rock Laboratory in Sweden. The objectives of the colloid project are to: (i) study the role of bentonite as a colloid source, (ii) verify the background colloid concentration at Aespoe HRL and, (iii) investigate the potential for colloid formation/transport in natural groundwater concentrations. The experimental concepts for the colloid project are: laboratory experiments with bentonite, background field measurements of natural colloids, borehole specific bentonite colloid stability experiments and a fracture specific transport experiment. The activities concerning the laboratory experiments and background field measurements are described in this work; the other activities are ongoing or planned. The following conclusions were made: The bentonite colloid stability is strongly dependent on the groundwater ionic strength. Natural colloids are organic degradation products such as humic and fulvic acids, inorganic colloids (clay, calcite, iron hydroxide) and microbes. Microbes form few but large particles and their concentration increase with increasing organic carbon concentrations. The small organic colloids are present in very low concentrations in deep granitic groundwater. The concentrations can be rather high in shallow waters. The colloid concentration decreases with depth and salinity, since colloids are less stable in saline waters. The colloid content at Aespoe is less than 300 ppb. The colloid content at repository level is less than 50 ppb. The groundwater variability obtained in the boreholes reflects well the natural groundwater variability along the whole HRL tunnel

  12. Aespoe Hard Rock Laboratory. Sensor Data Report No 23

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB (Sweden))

    2010-11-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 20010917-20100601. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by AaF) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements. Section 1. The following measurements are made in the bentonite in each of the two instrumented deposition holes in Section 1 (1 and 3): Temperature is measured in 32 points, total pressure in 27 points, pore water pressure in 14 points and relative humidity in 37 points. Temperature is also measured by all relative humidity gauges. Every measuring point is related to a local coordinate system in the deposition hole. The following measurements are made in the backfill in Section 1. Temperature is measured in 20 points, total pressure in 18 points, pore water pressure in 23 points and relative humidity in 45 points. Temperature is also measured by all relative humidity gauges. Furthermore, water content is measured by an electric chain in one section. Every measuring point is related to a local coordinate system in the tunnel. The following measurements are made on the surface of the canisters in Section 1: Temperature is measured every meter along two fiber optic cables. Furthermore, displacements of the canister in hole 3 are measured with 6 gauges. The following measurements are made in the rock in Section 1: Temperature is measured in 37 points in boreholes in the floor. Water

  13. Structural and neural network analyses of fracture systems at the Aespoe Hard Rock Laboratory, SE Sweden

    International Nuclear Information System (INIS)

    The > 10,000 fractures documented in the 450 m deep Aespoe Hard Rock Laboratory (HRL) provide a unique opportunity to study brittle deformation of a Swedish bedrock mass. The fracture population consists of six major sets, one sub-horizontal and five sub-vertical. A classical structural analysis explored the interrelations between geometry and frequency of both dry and wet fractures with respect to depth and in-situ stresses. Three main findings are: In-situ stresses govern frequency distributions of dilated, hence water-bearing fractures. About 68.5% of sub-horizontal fractures are dilated in the thrust regime above a depth of ca. 230 m while 53% of sub-vertical fractures are dilated in the underlying wrench regime. Fractures curve both horizontally and vertically, a finding confirmed by the application of artificial neural networks that included Back-Propagation and Self-Organizing (Kohonen) networks. The asymmetry of the total fracture population and tilts of the sub-Cambrian peneplain demonstrates that multiple reactivations of fractures have tilted the Aespoe rock mass 6 deg to the west. The potential space problem raised by this tilt is negated by systematic curvature of steep fractures, some of which sole out to gently dipping fracture zones. Fractures probably developed their curvature when they formed deep in crystalline crust in Precambrian times but have since reactivated at shallow depths. These findings add significantly to the conceptual model of Aespoe and should be taken into account in future studies regarding the isolation of Sweden's high-grade radioactive waste in crystalline bedrock

  14. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO3 composition at shallow depth to a CaCl2-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured EH values are generally near -300 mV, and on average are only about 50 mV lower than EH values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m2 per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the possible range of values that

  15. Aespoe Hard Rock Laboratory. Evaluation of scaling records for TASA access tunnel

    International Nuclear Information System (INIS)

    This report presents the result of a project accomplished during the summer 2009. It introduces a method to estimate the magnitude, mass distribution and cause of scaled blocks by tunnel mapping and evaluation of scaling data records. These issues are important for understanding the impact of the excavation method on the surrounding rock mass during excavation of the planned underground repository for spent nuclear fuel. The project includes mapping of the 3120 m drill and blast excavated part of the TASA access tunnel in the Aespoe Hard Rock Laboratory (HRL). In addition it includes development of a method for evaluation of the collected material together with scaling data records from the Site Characterization Database (SICADA). An interview has also been held with Erik Gabrielsson, who has been in charge of tunnel maintenance at Aespoe for many years. The mapping focused on to identify size and cause of areas with significant overbreaks in the tunnel roof. By distributing documented scaled volume in a tunnel section on several mapped overbreak areas in the same section it is possible to reconstruct the size of scaled blocks. The observed overbreak areas have been categorized in five different area types, depending on the cause of scaling: two geologically induced, one blast induced, one induced from a combination of geology and blasting and one unable to place in any category. For the calculated mass distribution the number of observations is declining with increasing block mass. 11% of the total blocks exceeding 400 Kg and 75% of the scaled blocks weights under 200 Kg. Most of the blocks are however lighter with 34% weighting 50 Kg or less. There is a relation between the mapped area type and the size distribution among the mapped overbreak areas. For example the areas caused by the end of blasting rounds are more frequently appearing then the other types but most of them are small in relation to the others The impression achieved from the tunnel mapping is

  16. Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

    International Nuclear Information System (INIS)

    This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

  17. Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Cuss, R.J.; Harrington, J.F.; Noy, D.J. (British Geological Survey (United Kingdom))

    2010-02-15

    This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

  18. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, A. [Conterra AB, Uppsala (Sweden); Andersson, Peter [Geosigma AB, Uppsala (Sweden); Hermanson, Jan [Golder Grundteknik, Solna (Sweden); Byegaard, Johan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Cvetkovic, V. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Water Resources Engineering; Birgersson, Lars [Kemakta Konsult AB, Stockholm (Sweden)

    2000-03-15

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (< 0.5 m), detailed scale (< 10 m) and block scale (10-50 m). The First TRUE Stage was performed in the detailed scale with the specific objectives of providing data and conceptualising the investigated feature using conservative and sorbing tracers. Further, to improve methodologies for performing tracer tests, and to develop and test a methodology for obtaining pore volume/aperture data from epoxy resin injection, excavation and subsequent analyses. The experimental site is located at approximately 400 m depth in the northeastern part of the Aespoe Hard Rock Laboratory. The identification of conductive fractures and the target feature has benefited from the use of BIPS borehole TV imaging combined with detailed flow logging. The assessment of the conductive geometry has been further sustained by cross-hole pressure interference data. The investigated target feature (Feature A) is a reactivated mylonite which has later undergone brittle deformation. The feature is oriented northwest, along the principal horizontal stress orientation, and is a typical conductor for Aespoe conditions. Hydraulic characterisation shows that the feature is relatively well isolated

  19. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P.D.; Voss, C.I. [US Geological Survey, Reston, VA (United States)

    1999-09-01

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO{sub 3} composition at shallow depth to a CaCl{sub 2}-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured E{sub H} values are generally near -300 mV, and on average are only about 50 mV lower than E{sub H} values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m{sup 2} per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the

  20. Site characterization survey at the Aespoe Hard Rock Laboratory of SKB, Sweden. Overview of the geotechnological survey

    International Nuclear Information System (INIS)

    Swedish Nuclear Fuel and Waste Management Company (SKB) is operating a Hard Rock Laboratory (HRL) at the Aespoe island in southeastern Sweden, to develop new technologies concerning High Level Waste (HLW) disposal, and to be useful for the safety assessment and survey of the candidate sites for HLW disposal by applying and verifying the test and survey methods developed before. Many in-situ experiments in operation phase are on going or planned at the Aespoe HRL. This paper describes an outline of in-situ experiments in both construction and operation phase, and geological and hydrological surveys during construction and fracture estimation method which can provide basic data for the estimations of groundwater flow and radionuclide migration. (author)

  1. Aespoe hard rock laboratory. Field investigation methodology and instruments used in the preinvestigation phase, 1986-1990

    International Nuclear Information System (INIS)

    The Aespoe hard rock laboratory project started in 1986. The pre-investigation phase, 1986-1990, involved extensive field measurements from the surface as well as from boreholes, aimed at characterizing the rock formation with regard to geology, geohydrology, hydrochemistry and rock mechanics. The field investigation methodology used in the project was based on experience from and developments during the previous SKB study site investigation programme. However, in some respects the techniques were changed or modified. Major changes have been possible due to a new drilling technique, telescope-type drilling. This report describes the logistics of the investigation programme, characterized to a large extent by multi-purpose planning and performance of the activities in order to optimize the use of available resources; time, personnel and equipment. Preliminary hydraulic testing and groundwater sampling were conducted during the drilling of each borehole. When the drilling was completed an extensive set of singlehole investigations were carried out: geophysical logging, borehole radar, hydraulic tests of different kinds, water sampling and rock stress measurements. Multipackers were installed in the boreholes as soon as possible after the borehole investigations. The system enables monitoring of groundwater pressure, water sampling and groundwater flow measurements to be performed by means of dilution tests and tracer injection. Boreholes with such equipment were used as observation holes during interference pumping tests and long term hydraulic and tracer tests. The monitoring programme will continue during the subsequent phases of construction and operation of the Aespoe hard rock laboratory. (83 refs., 94 figs.) (au)

  2. Towards a new generation of flow and transport models for the Aespoe Hard Rock Laboratory. Main results from the project Aespoe models 2005

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Urban (ed.) (Computer-aided Fluid Engineering AB (CFE AB), SE-602 10 Norrkoeping (Sweden)); Vidstrand, Patrik (Bergab AB, Goeteborg (Sweden)); Neretnieks, Ivars (Dept. of Chemical Engineering and Technology, Royal Inst. of Technology, Stockholm (Sweden)); Wallin, Bill (Geokema, Lidingoe (Sweden))

    2008-05-15

    This report constitutes the outcome of a project called 'Aespoe models 2005'. The main objective of the project has been to provide a first step towards a new generation of numerical models of flow and transport, for the Aespoe HRL. In order to achieve this goal, work has been carried out along three parallel lines; discussion of basic concepts, compilation and analysis of data and model applications. A number of sub tasks are reported as appendices in the report. In fact, these appendices represent the main achievements of the project: an analysis of fracture properties, compilation of isotope and chemical data, dispersion and mixing in fractured rocks and model results. The conclusion of the project is that significant contributions to a new generation of Aespoe models have been obtained. It has further been demonstrated that working numerical simulations are up and running. Recommendations are provided for the continued work

  3. Towards a new generation of flow and transport models for the Aespoe Hard Rock Laboratory. Main results from the project Aespoe models 2005

    International Nuclear Information System (INIS)

    This report constitutes the outcome of a project called 'Aespoe models 2005'. The main objective of the project has been to provide a first step towards a new generation of numerical models of flow and transport, for the Aespoe HRL. In order to achieve this goal, work has been carried out along three parallel lines; discussion of basic concepts, compilation and analysis of data and model applications. A number of sub tasks are reported as appendices in the report. In fact, these appendices represent the main achievements of the project: an analysis of fracture properties, compilation of isotope and chemical data, dispersion and mixing in fractured rocks and model results. The conclusion of the project is that significant contributions to a new generation of Aespoe models have been obtained. It has further been demonstrated that working numerical simulations are up and running. Recommendations are provided for the continued work

  4. Aespoe Hard Rock Laboratory: Evaluation of the combined longterm pumping and tracer test (LPT2) in borehole KAS06

    International Nuclear Information System (INIS)

    This report summarizes the results from the LPT2 experiment. The field experiment had three major parts: a pumping test, a tracer experiment and a tracer dilution experiment. These are described in detail in the appendices of the report. Numerical simulations have been carried out both prior to and after the experiments. Results from these are also reported. The longterm pumping test and tracer test performed in KAS06, called LPT2, was the first attempt to clarify the transport of solutes in the site scale of Aespoe. The test was not intended to be complete regarding the transport parameters needed for nuclide transport modelling. In the operating phase of the Aespoe Hard Rock Laboratory more detailed tracer tests and numerical modelling will be conducted. The main conclusion from the field experiment is that the present conceptual model of Aespoe is sound, but some modifications may be required. These include both the extension and transmissivities of fracture zones. The field experiment has also produced additional information on the properties of the fracture zones like porosity and dispersivity. The cumulative aperture of all hydraulic fractures was estimated to 10x10-3 - 30x10-3 m for two different sets of zones. Considering the estimated width of the zones the flow porosities were estimated to 0.02-0.1 %. The dispersivities were estimated to 0.1-0.2 of the flow path distance and the Peclet number to 4-11. The numerical simulations made prior to the experiment, dealing with the travel time of tracers, were found to be in reasonable agreement with the measurements. The data gathered in the field experiment will however make it possible to pursue the modelling efforts further

  5. SKN's review of the preinvestigations for the Aespoe hard rock Laboratory

    International Nuclear Information System (INIS)

    This report is a review of the preinvestigations for the planned hard rock laboratory. The geological and hydrogeological conditions have been investigated as well as mathematical simulation of the groundwater conditions. (57 refs.) (K.A.E.)

  6. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-12-15

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  7. SITE 94. Modelling of groundwater chemistry at Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    In this report a model is described, which has been able to give agreement between observed and modelled values for more than ten element concentrations (including pH and pE values). The model makes use of a number of steady state waters which are mixed naturally after which the mixtures react with minerals in the fractures. The end member waters are supposed to have been present in the fracture system during a time interval which is long enough for the rock groundwater system to have reached a steady state. Some elements, e.g. chlorine, is modelled as conservative (inert with respect to the rock). Most element concentrations cannot be explained from mixing alone. Rather reactions with the fracture walls have to be taken into account. The situation is complicated by the fact that a system comprised of groundwater and a number of fracture minerals may violate Gibb's phase rule. In such a system, no global equilibrium state exists, and thus the water can never reach equilibrium with respect to all the fracture minerals. The end member waters eventually formed can be expected to be in a steady state condition rather than equilibrium with respect to the fracture minerals. It should be noted that such a steady state is not an equilibrium state. Rather, the water chemistry has to fluctuate as a result of spatial variability in the local mineral set. In most cases when an end member water is sampled, a large number of local waters are mixed causing the fluctuations to cancel out. The CRACKER is a program which has been developed to handle this complicated chemical situation. It couples chemistry and transport, using elaborate chemical modelling in combination with a simplified transport model. The program simulates chemical reactions of groundwater flowing through a plane fracture. The simulation results show that although the end member waters are far from equilibrium with respect to most of the minerals, they are in a steady state with respect to the rock. The chemistry

  8. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    International Nuclear Information System (INIS)

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  9. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    International Nuclear Information System (INIS)

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (22Na+ 47Ca2+ ≅ 85Sr2+ 86Rb+ ≅ 133Ba2+ The field tracer tests, using essentially the same cocktail of sorbing tracers as in the laboratory, were found to show the same relative sorbtivity as seen in the laboratory. A test using 137Cs showed that after termination of the test, some 63% of the injected activity remained sorbed in the rock. The interpretation of the in situ tests with sorbing tracers was performed using the LaSAR approach, developed as a part of the TRUE project. In this approach the studied flow path is viewed as a part of an open fracture. Key processes are spatially variable advection and mass transfer. The evaluation shows that laboratory diffusion data are not representative for in situ conditions, and that a close fit between field and modelled breakthrough is obtained only when a parameter group which includes diffusion is enhanced with a factor varying between 32-50 for all tracers and experiments (except for Cs) and 137 for Cs. Our interpretation is that the enhancement is mainly due to higher diffusivity/porosity and higher sorption in the part of the altered rim zone of the feature which is accessible over the time scales of the in

  10. New developments of the Integrated Stress Determination Method and application to the Aespoe Hard Rock Laboratory, Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Ask, Daniel

    2004-04-01

    This thesis presents new developments of the Integrated Stress Determination Method (ISDM) with application to the Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The new developments involve a 12-parameter representation of the regional stress field in the rock mass. The method is applicable to data from hydraulic fracturing, hydraulic tests on pre-existing fractures (HTPF), and overcoring data from CSIR- and CSIRO-type of devices. When hydraulic fracturing/HTPF data are combined with overcoring data, the former may be used to constrain the elastic parameters, i.e. the problem involves 14 model parameters. The Swedish Nuclear Fuel and Waste Management Co. (SKB), have conducted a vast amount of rock stress measurements at the Aespoe HRL since the late 1980s. However, despite the large number of stress measurement data collected in this limited rock volume, variability in the stress field exists. Not only does the result vary depending on measuring technique, e.g. overcoring data indicated larger stress magnitudes compared to hydraulic fracturing data; the results are also affected by existing discontinuities, indicated by non-linear stress magnitudes and orientations versus depth. The objectives for this study are therefore threefold: (1) find explanations to the observed differences between existing hydraulic and overcoring stress data at the Aspo HRL; (2) explain the non-linear stress distribution indicated by existing stress data; and (3) apply the ISDM, including the new developments, based on the results obtained in step 1 and 2. To evaluate the observed differences between existing hydraulic and overcoring stress data, a detailed re-interpretation was conducted. Several measurement-related uncertainties were identified and corrected for when possible, which effectively reduced the discrepancies between the hydraulic and overcoring measuring results. Modeling studies managed by SKB have shown that the redistribution of the stresses at Aespoe HRL to a

  11. New developments of the Integrated Stress Determination Method and application to the Aespoe Hard Rock Laboratory, Sweden

    International Nuclear Information System (INIS)

    This thesis presents new developments of the Integrated Stress Determination Method (ISDM) with application to the Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The new developments involve a 12-parameter representation of the regional stress field in the rock mass. The method is applicable to data from hydraulic fracturing, hydraulic tests on pre-existing fractures (HTPF), and overcoring data from CSIR- and CSIRO-type of devices. When hydraulic fracturing/HTPF data are combined with overcoring data, the former may be used to constrain the elastic parameters, i.e. the problem involves 14 model parameters. The Swedish Nuclear Fuel and Waste Management Co. (SKB), have conducted a vast amount of rock stress measurements at the Aespoe HRL since the late 1980s. However, despite the large number of stress measurement data collected in this limited rock volume, variability in the stress field exists. Not only does the result vary depending on measuring technique, e.g. overcoring data indicated larger stress magnitudes compared to hydraulic fracturing data; the results are also affected by existing discontinuities, indicated by non-linear stress magnitudes and orientations versus depth. The objectives for this study are therefore threefold: (1) find explanations to the observed differences between existing hydraulic and overcoring stress data at the Aspo HRL; (2) explain the non-linear stress distribution indicated by existing stress data; and (3) apply the ISDM, including the new developments, based on the results obtained in step 1 and 2. To evaluate the observed differences between existing hydraulic and overcoring stress data, a detailed re-interpretation was conducted. Several measurement-related uncertainties were identified and corrected for when possible, which effectively reduced the discrepancies between the hydraulic and overcoring measuring results. Modeling studies managed by SKB have shown that the redistribution of the stresses at Aespoe HRL to a

  12. Aespoe Hard Rock Laboratory. Studies of factors that affect and controls the Excavation Damaged/Disturbed Zone

    International Nuclear Information System (INIS)

    A tunnel was developed at the Aespoe Hard Rock Laboratory (HRL) in 2003 purposely for a large in-situ rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). The tunnel had a large height/width ratio with a circular floor, primarily to control the stress situation around the tunnel and concentrate the stresses under the floor. An extensive set of data for understanding the Excavation Damaged Zone (EDZ) was collected within section 47 of the tunnel. It consist of the blast design, blast sequences, convergence measurements during excavation, geological mapping of tunnel and cores, 3D-laser scanning of the tunnel geometry etc. Furthermore, in 2006, ultrasonic measurements along eight boreholes were carried out in order to estimate the extent of the EDZ in the tunnel. The collection of all these different information provides an opportunity to evaluate the mechanical damages caused by the excavation work. The overall aim with this project is to give feed-back to future planning of tunnelling on issues of importance for requirements with respect to minimising the EDZ in crystalline rock from the drill and blast method. A combination of the mapped geological features (tunnel and cores) and the geometry of the blasted tunnel obtained from the 3D-laser scanning were used to build a 3D model of the geology with emphasis on the geometry of the natural fractures. The rock mechanic response to the tunnelling was evaluated in a numerical model including the as-built geometry in combination with the 3D model of the geology. The modelling of the rock mechanical processes of importance for the EDZ could be calibrated against actual measurements. From observed changes in the ultrasonic wave velocity along the boreholes it was found that the locations of the velocity changes corresponded well with the location of the mapped fractures in the drill cores. This indicates that EDZ can be detected using the ultrasonic method with high accuracy. Furthermore, the

  13. Aespoe Hard Rock Laboratory. Studies of factors that affect and controls the Excavation Damaged/Disturbed Zone

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Martin; Baeckstroem, Ann; Quanhong Feng (AaF - Berg och Maetteknik, Stockholm (Sweden)); Berglund, Johan (Vattenfall Power Consultant, Stockholm (Sweden)); Johansson, Malin; Mas Ivars, Diego (Itasca Geomekanik AB, Solna (Sweden)); Olsson, Mats (SweBefo, Stockholm (Sweden))

    2009-07-15

    A tunnel was developed at the Aespoe Hard Rock Laboratory (HRL) in 2003 purposely for a large in-situ rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). The tunnel had a large height/width ratio with a circular floor, primarily to control the stress situation around the tunnel and concentrate the stresses under the floor. An extensive set of data for understanding the Excavation Damaged Zone (EDZ) was collected within section 47 of the tunnel. It consist of the blast design, blast sequences, convergence measurements during excavation, geological mapping of tunnel and cores, 3D-laser scanning of the tunnel geometry etc. Furthermore, in 2006, ultrasonic measurements along eight boreholes were carried out in order to estimate the extent of the EDZ in the tunnel. The collection of all these different information provides an opportunity to evaluate the mechanical damages caused by the excavation work. The overall aim with this project is to give feed-back to future planning of tunnelling on issues of importance for requirements with respect to minimising the EDZ in crystalline rock from the drill and blast method. A combination of the mapped geological features (tunnel and cores) and the geometry of the blasted tunnel obtained from the 3D-laser scanning were used to build a 3D model of the geology with emphasis on the geometry of the natural fractures. The rock mechanic response to the tunnelling was evaluated in a numerical model including the as-built geometry in combination with the 3D model of the geology. The modelling of the rock mechanical processes of importance for the EDZ could be calibrated against actual measurements. From observed changes in the ultrasonic wave velocity along the boreholes it was found that the locations of the velocity changes corresponded well with the location of the mapped fractures in the drill cores. This indicates that EDZ can be detected using the ultrasonic method with high accuracy. Furthermore, the

  14. Aespoe Hard Rock Laboratory. Analysis of fracture networks based on the integration of structural and hydrogeological observations on different scales

    International Nuclear Information System (INIS)

    Fracture networks at Aespoe have been studied for several rock types exhibiting different degrees of ductile and brittle deformation, as well as on different scales. Mesoscopic fault systems have been characterised and classified in an earlier report, this report focuses mainly on fracture networks derived on smaller scales, but also includes mesoscopic and larger scales. The TRUE-1 block has been selected for detailed structural analysis on a small scale due to the high density of relevant information. In addition to the data obtained from core materials, structural maps, BIP data and the results of hydro tests were synthesised to derive a conceptual structural model. The approach used to derive this conceptual model is based on the integration of deterministic structural evidence, probabilistic information and both upscaling and downscaling of observations and concepts derived on different scales. Twelve fracture networks mapped at different sites and scales and exhibiting various styles of tectonic deformation were analysed for fractal properties and structural and hydraulic interconnectedness. It was shown that these analysed fracture networks are not self-similar. An important result is the structural and hydraulic interconnectedness of fracture networks on all scales in the Aespoe rocks, which is further corroborated by geochemical evidence. Due to the structural and hydraulic interconnectedness of fracture systems on all scales at Aespoe, contaminants from waste canisters placed in tectonically low deformation environments would be transported - after having passed through the engineered barriers -from low-permeability fractures towards higher permeability fractures and may thus eventually reach high-permeability features

  15. Aespoe Hard Rock Laboratory. Analysis of fracture networks based on the integration of structural and hydrogeological observations on different scales

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, P. [Geotechnical Inst. Ltd., Bern (Switzerland); Hermanson, Jan [Golder Associates, Stockholm (Sweden); Mazurek, M. [Univ. of Bern (Switzerland)

    2001-05-01

    Fracture networks at Aespoe have been studied for several rock types exhibiting different degrees of ductile and brittle deformation, as well as on different scales. Mesoscopic fault systems have been characterised and classified in an earlier report, this report focuses mainly on fracture networks derived on smaller scales, but also includes mesoscopic and larger scales. The TRUE-1 block has been selected for detailed structural analysis on a small scale due to the high density of relevant information. In addition to the data obtained from core materials, structural maps, BIP data and the results of hydro tests were synthesised to derive a conceptual structural model. The approach used to derive this conceptual model is based on the integration of deterministic structural evidence, probabilistic information and both upscaling and downscaling of observations and concepts derived on different scales. Twelve fracture networks mapped at different sites and scales and exhibiting various styles of tectonic deformation were analysed for fractal properties and structural and hydraulic interconnectedness. It was shown that these analysed fracture networks are not self-similar. An important result is the structural and hydraulic interconnectedness of fracture networks on all scales in the Aespoe rocks, which is further corroborated by geochemical evidence. Due to the structural and hydraulic interconnectedness of fracture systems on all scales at Aespoe, contaminants from waste canisters placed in tectonically low deformation environments would be transported - after having passed through the engineered barriers -from low-permeability fractures towards higher permeability fractures and may thus eventually reach high-permeability features.

  16. The Aespoe Hard Rock Laboratory: Final evaluation of the hydrogeochemical pre-investigations in relation to existing geologic and hydraulic conditions

    International Nuclear Information System (INIS)

    The Swedish Nuclear Fuel and Management Company (SKB) is currently excavating the access tunnel to an underground experimental laboratory, the Aespoe Hard Rock Laboratory, planned to be located some 500 m below the island of Aespoe which is located in the Simpevarp area, southeast Sweden. The construction of an underground laboratory forms part of the overall SKB strategy to test, not only the construction techniques for deep excavation, but also the various methods and protocols required to obtain a three-dimensional model of the geology and groundwater flow and chemistry, within a fractured crystalline bedrock similar to that envisaged for the final disposal of spent fuel. Aespoe was chosen because it geologically represents a variety of typical crystalline bedrock environments. The hydrogeochemical activities described and interpreted in this report form part of the initial pre-investigation phase (from the surface to around 1000 metres depth) aimed at siting the laboratory, describing the natural hydrogeological and hydrogeochemical conditions in the bedrock and predicting the changes that will occur during excavation and construction of the laboratory. Hydrogeochemical interpretation has therefore been closely integrated with the hydrogeological investigations and other disciplines of major influence, in particular, bedrock geology and geochemistry and fracture mineralogy and chemistry. A large section of this report has been devoted to the detailed investigation of each individual zone hydraulically selected, tested and sampled for hydrogeochemical characterization. The data have been used to describe the chemistry and origin of the Aespoe groundwaters, models have been developed to illustrate groundwater mixing and standard geochemical modelling approaches have been employed to understand rock/water interaction processes. An attempt has been made to integrate the hydrogeochemical information with known geological and hydrogeological parameters to construct a

  17. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-081201) Report No: 20

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-03-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-081201. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by BBK) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  18. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-091201) Report No: 22

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-12-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-091201. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by AaF) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  19. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-090601) Report No: 21

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-07-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-090601. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by BBK) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  20. SITE-94. Natural elemental mass movement in the vicinity of the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The primary objective of this study is to quantify natural elemental fluxes at a location exhibiting typical characteristics of a site for a spent fuel repository in Sweden. The relevant pathways are considered to be: Groundwater transport; Glacial erosion; Non-glacial weathering; River transport. Calculations are made of elemental mass fluxes from a volume of rock equivalent to that which would hold a KBS-3 style repository. In addition, the radioactive flux associated with the natural series radionuclide mass fluxes from the repository are also calculated. These can be compared directly to performance assessment predictions of the releases from a repository. 88 refs, 13 figs, 24 tabs

  1. SITE-94. Natural elemental mass movement in the vicinity of the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.M.; Smith, G.M.; Towler, P.A.; Savage, D. [QuantiSci, Melton Mowbray (United Kingdom)

    1997-05-01

    The primary objective of this study is to quantify natural elemental fluxes at a location exhibiting typical characteristics of a site for a spent fuel repository in Sweden. The relevant pathways are considered to be: Groundwater transport; Glacial erosion; Non-glacial weathering; River transport. Calculations are made of elemental mass fluxes from a volume of rock equivalent to that which would hold a KBS-3 style repository. In addition, the radioactive flux associated with the natural series radionuclide mass fluxes from the repository are also calculated. These can be compared directly to performance assessment predictions of the releases from a repository. 88 refs, 13 figs, 24 tabs.

  2. Preliminary results from mineralogical and chemical investigation of the prototype repository at Aespoe hard rock laboratory, Sweden

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. The Prototype Repository is a large-scale experiment installed at Aespoe Hard Rock Laboratory, Sweden. The experiment consists of six full-scale deposition holes at 450 meters depth. Each deposition hole is installed with full-scale bentonite buffer and a full-scale copper canister are installed. The canisters are equipped with heaters to simulate the heat generation from radioactive waste. The experiment is divided into two sections; the inner section consists of four deposition holes and the outer section of two deposition holes. The deposition tunnel is backfilled with a mixture of crushed rock and bentonite. The experiment also includes two concrete plugs at the end of each section. Furthermore, sensors are installed in the rock, backfill and buffers to monitor the pressure build-up and wetting of buffer and backfill. The installation of buffers, canisters with heaters, packing of backfill, and also the making of concrete plugs were done during the period 2001-2003. Heating of the canisters in the two sections was started successively after the filling of the tunnel had reached the deposition holes. The heaters in canister 1 were activated in October 2001 and the heaters in canister 6 were activated in May 2003. Natural wetting from the rock of buffer and backfill continued from that date until the dismantling stared at the end of 2010. The heaters in the two canisters in outer section were switched off in January 2011 and July 2011, respectively. During 2011 the bentonite was excavated and sampled in vacuum sealed aluminium laminate bags prior to the analysis. The hydro-mechanical, chemical, mineralogical and microbiological properties of the bentonite buffer are investigated. The formation water and gas samples are analysed and also the rock and the canister. Here we present preliminary results from the mineralogical and chemical investigations of selected blocks from the bentonite buffer material excavated

  3. Aespoe Hard Rock Laboratory. Prototype Repository. Analyses of microorganisms, gases and water chemistry in buffer and backfill, 2009

    International Nuclear Information System (INIS)

    The Prototype repository is an international project to build and study a full-scale model of the planned Swedish final repository for spent nuclear fuel. The Prototype repository differs from a real storage in that it is drained. For example, this makes the swelling pressure lower in the Prototype repository compared with a real storage. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and one of the specific aims is to monitor the microbial consumption of oxygen in situ in the Prototype repository. This document describes the results of the analyses of microbes, gases, and chemistry inside and outside the Prototype in 2009. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed in the following sampling points in the Prototype repository: KBU10001, KBU10002, KBU10004, KBU10006, KBU10008, KFA01 and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e., the biovolume), cultivable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), autotrophic acetogens (AA) and in some cases iron-reducing bacteria (IRB). Cultivation methods were also compared with qPCR molecular techniques to evaluate these before next year's decommission of the Prototype repository. The collected pore water from the Prototype repository was subject to chemistry analysis (as many analyses were conducted as the amount of water allowed). In addition, groundwater from two borehole sections in the rock surrounding the Prototype was analysed regarding its gas composition, microbiology and redox. Chemistry data from a previous investigation of the groundwater outside the Prototype repository were compared with the pore water chemistry

  4. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    International Nuclear Information System (INIS)

    'Canister Retrieval Test' (CRT) is an experiment that started at Aespoe Hard Rock Laboratory (HRL) 2000. CRT is a part of the investigations which evaluate a possible KBS-3 storage of nuclear waste. The primary aim was to see whether it is possible or not to retrieve a copper canister after storage under authentic KBS-3 conditions. However, CRT also provided a unique opportunity to investigate if bacteria survived in the bentonite buffer during storage. Therefore, in connection to the retrieval of the canister microbiological samples were extracted from the bentonite buffer and the bacterial composition was studied. In this report, microbiological analyses of a total of 66 samples at the C2, R10, R9 and R6 levels in the bentonite from CRT are presented and discussed. By culturing bacteria from the bentonite in specific media the following bacterial parameters were investigated: The total amount of culturable heterotrophic aerobic bacteria, sulphate-reducing bacteria, and bacteria that produce the organic compound acetate (acetogens). The biovolume in the bentonite was determined by detection of the ATP content. In addition, bacteria from the bentonite were cultured in different sulphate-reducing media. In these cultures, the presence of the biotic compounds sulphide and acetate was investigated, since these have potentially negative effect on the copper canister in a KBS-3 repository. The results were to some extent compared to density, water content, and temperature data provided by Clay Technology AB. The results showed that 100-102 viable sulphate-reducing and acetogenic bacteria and 102-104 heterotrophic aerobic bacteria g-1 bentonite were present after five years of storage in the rock. Bacteria with several morphologies could be found in the cultures with bentonite. The most bacteria were detected in the bentonite buffer close to the rock but in a few samples also in bentonite close to the copper canister. When the presence of bacteria in the bentonite is

  5. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara; Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden))

    2011-03-15

    'Canister Retrieval Test' (CRT) is an experiment that started at Aespoe Hard Rock Laboratory (HRL) 2000. CRT is a part of the investigations which evaluate a possible KBS-3 storage of nuclear waste. The primary aim was to see whether it is possible or not to retrieve a copper canister after storage under authentic KBS-3 conditions. However, CRT also provided a unique opportunity to investigate if bacteria survived in the bentonite buffer during storage. Therefore, in connection to the retrieval of the canister microbiological samples were extracted from the bentonite buffer and the bacterial composition was studied. In this report, microbiological analyses of a total of 66 samples at the C2, R10, R9 and R6 levels in the bentonite from CRT are presented and discussed. By culturing bacteria from the bentonite in specific media the following bacterial parameters were investigated: The total amount of culturable heterotrophic aerobic bacteria, sulphate-reducing bacteria, and bacteria that produce the organic compound acetate (acetogens). The biovolume in the bentonite was determined by detection of the ATP content. In addition, bacteria from the bentonite were cultured in different sulphate-reducing media. In these cultures, the presence of the biotic compounds sulphide and acetate was investigated, since these have potentially negative effect on the copper canister in a KBS-3 repository. The results were to some extent compared to density, water content, and temperature data provided by Clay Technology AB. The results showed that 100-102 viable sulphate-reducing and acetogenic bacteria and 102-104 heterotrophic aerobic bacteria g-1 bentonite were present after five years of storage in the rock. Bacteria with several morphologies could be found in the cultures with bentonite. The most bacteria were detected in the bentonite buffer close to the rock but in a few samples also in bentonite close to the copper canister. When the presence of bacteria in the

  6. Aespoe Hard Rock Laboratory. Prototype Repository. Analyses of microorganisms, gases and water chemistry in buffer and backfill, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara (Microbial Analytics Sweden AB (Sweden))

    2010-09-15

    The Prototype repository is an international project to build and study a full-scale model of the planned Swedish final repository for spent nuclear fuel. The Prototype repository differs from a real storage in that it is drained. For example, this makes the swelling pressure lower in the Prototype repository compared with a real storage. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and one of the specific aims is to monitor the microbial consumption of oxygen in situ in the Prototype repository. This document describes the results of the analyses of microbes, gases, and chemistry inside and outside the Prototype in 2009. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed in the following sampling points in the Prototype repository: KBU10001, KBU10002, KBU10004, KBU10006, KBU10008, KFA01 and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e., the biovolume), cultivable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), autotrophic acetogens (AA) and in some cases iron-reducing bacteria (IRB). Cultivation methods were also compared with qPCR molecular techniques to evaluate these before next year's decommission of the Prototype repository. The collected pore water from the Prototype repository was subject to chemistry analysis (as many analyses were conducted as the amount of water allowed). In addition, groundwater from two borehole sections in the rock surrounding the Prototype was analysed regarding its gas composition, microbiology and redox. Chemistry data from a previous investigation of the groundwater outside the Prototype repository were compared with the pore water

  7. Aespoe Hard Rock Laboratory - feasibility and usefulness of site investigation methods. Experiences from the pre-investigation phase

    International Nuclear Information System (INIS)

    One of the main goals set up by SKB for the Aespoe HRL project is to 'test the quality and appropriateness of different methods for characterizing the bedrock with respect to conditions of importance for a final repository'. An extensive investigation programme was carried out during the projects pre-investigation phase that in part was based in experience from SKBs previous site investigations and in part entailed the testing of new or other unestablished methods. Previous technical reports have described the methods that have been used and the results, models and predictions that have been produced. All the methods used are discussed in the present report in terms of how they have contributed in different analysis stages to the total geoscientific characterization of the rock at Aespoe. The usefulness of each method for modelling and prediction in different scales is evaluated, and aspects of the practical execution of the methods under different conditions are discussed. The report sheds light on the importance of dividing large investigation programmes such as this one into suitable stages to get an opportunity to evaluate the results obtained and plan in detail the investigations in the next stage. Furthermore, the way in which the characterization/modelling work in different geometric scales has been done for the different investigation stages is discussed, along with whether this has been found to be a suitable approach. The importance of pursuing an interdisciplinary strategy throughout the pre-investigation process cannot be overemphasized. For the planning, execution, analysis and reporting of the results of the pre-investigations, this has been guaranteed by an organization in which an interdisciplinary group has been in charge of the investigations, together with the project manager. 52 refs, numerous tabs and figs

  8. Aespoe Hard Rock Laboratory. Backfill and Plug test. Hydraulic testing of core drilled boreholes in the ZEDEX drift

    International Nuclear Information System (INIS)

    The present report documents the performance and results of hydraulic testing in selected core boreholes in the Zedex drift. The holes will be used as rock instrumentation boreholes during the Backfill and Plug Test at Aespoe HRL. The testing involves both 1 m long boreholes with 56 mm diameter as well as longer boreholes c. 5 m, 8 m and 25 m long with 56 mm or 76 mm diameter. Only single-hole tests were performed. The tests were carried out as short-time constant head injection tests since all boreholes tested (except one) were non-flowing before tests. The injection phase was followed by a pressure recovery phase. Furthermore, the tests were carried out as single-packer tests. A specially designed test system was used for the tests. The main evaluation of the tests was performed on data from the recovery phase by a new approach based on a non-linear regression technique combined with a flow simulation model (SUTRA). The tests in the 1 m-holes (testing the interval c. 0.3-0.7 m in the rock perpendicular to the tunnel face) show that the hydraulic conductivity of the superficial rock around the Zedex drift in general is low. However, during testing in some boreholes, visible leakage in the rock occurred through superficial fractures into the tunnel. These fractures were mainly located in the floor of the Zedex drift and are probably blast-induced. These fractures have a high hydraulic conductivity. The tests in the longer boreholes show that the hydraulic conductivity further into the rock in general is below c. 1x10-10 m/s. Increased hydraulic conductivity (c.1.5x10-8 m/s) was only observed in the flowing borehole KXZSD8HL

  9. Aespoe Hard Rock Laboratory. Prototype repository. Analyses of microorganisms, gases, and water chemistry in buffer and backfill, 2010

    International Nuclear Information System (INIS)

    The prototype repository (hereafter, 'Prototype') is an international project to build and study a fullscale model of the planned Swedish final repository for spent nuclear fuel. However, the Prototype differs from a real storage in that it is drained, which makes the swelling pressure lower in the Prototype than in a real storage facility. The heat from the radioactive decay is simulated by electrical heaters. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and a specific aim is to monitor the microbial consumption of oxygen in situ in the Prototype. This document describes the results of the analyses of microbes, gases, and chemistry inside the Prototype in 2010. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed at the following sampling points in the Prototype: KBU10001, KBU10002, KBU10004, KBU10008, and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e. the biovolume), culturable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), and iron-reducing bacteria (IRB). The pore water collected from the Prototype was subject to as many chemical analyses as the amount of water allowed. Chemical analyses were also performed on pore water from two additional sampling points, KBU10005 and KBU10006. Chemical data from a previous investigation of the groundwater outside the Prototype were compared with the pore water chemistry. The improved sampling and analysis protocols introduced in 2007 worked very well. The International Progress Report (IPR) 08-01 (Eriksson 2008) revealed that many of the hydrochemical sampling points differ greatly from each other. The 16 sampling points were therefore

  10. Aespoe Hard Rock Laboratory. Prototype repository. Analyses of microorganisms, gases, and water chemistry in buffer and backfill, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara [Microbial Analytics Sweden AB, Moelnlycke (Sweden)

    2011-06-15

    The prototype repository (hereafter, 'Prototype') is an international project to build and study a fullscale model of the planned Swedish final repository for spent nuclear fuel. However, the Prototype differs from a real storage in that it is drained, which makes the swelling pressure lower in the Prototype than in a real storage facility. The heat from the radioactive decay is simulated by electrical heaters. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and a specific aim is to monitor the microbial consumption of oxygen in situ in the Prototype. This document describes the results of the analyses of microbes, gases, and chemistry inside the Prototype in 2010. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed at the following sampling points in the Prototype: KBU10001, KBU10002, KBU10004, KBU10008, and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e. the biovolume), culturable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), and iron-reducing bacteria (IRB). The pore water collected from the Prototype was subject to as many chemical analyses as the amount of water allowed. Chemical analyses were also performed on pore water from two additional sampling points, KBU10005 and KBU10006. Chemical data from a previous investigation of the groundwater outside the Prototype were compared with the pore water chemistry. The improved sampling and analysis protocols introduced in 2007 worked very well. The International Progress Report (IPR) 08-01 (Eriksson 2008) revealed that many of the hydrochemical sampling points differ greatly from each other. The 16 sampling points were

  11. Bacterial sulphate reduction and mixing processes at the Aespoe Hard Rock Laboratory indicated by groundwater δ34S isotope signatures

    International Nuclear Information System (INIS)

    This report includes data mostly obtained from δ34S isotope measurements of groundwater at the Aespoe Island and one sampling from the Laxemar site, southeastern Sweden, during tunnel construction. Early sampling at Aespoe (up to 1992), before tunnel excavation, indicates a groundwater system with multiple sulphur sources. The isotope changes over time in the dissolved sulphate were studied during a sampling campaign in the monitoring phase from 1993 to 1995. A total of 88 samples were collected by SKB between 1992 and 1995 from core-drilled surface boreholes and from boreholes drilled in the tunnel (34 of these samples were collected from the tunnel boreholes). The results of the analyses have been the focus of discussion of the isotope changes with time in the dissolved sulphate (SO42-). The results indicate that the sulphur isotope signatures in the dissolved sulphate of the groundwater and those from fracture-filling sulphides at Aespoe originate from multiple sulphur sources in the groundwater at Aespoe and Laxemar. The data may be grouped as follows: a) typically homogeneous marine signatures of dissolved SO42- are observed, with δ34S values of approximately +21 per mille CDT at intermediate depths of approximately 100-250 m; b) dissolved sulphate in the groundwater at greater depths (below 600 m) with average values of approximately +10 per mille CDT; and c) a dissolved SO42- originating from a mixture of these sulphur sources (100-600m), although there is a difference between a mixture and modification by reduction. Reduced sulphur with low δ34S values is also recorded in fracture-filling sulphides, with δ34S values of approximately 0 to -10 per mille CDT. This may contribute to small changes in the isotope signature of the dissolved SO42-, probably by sulphide oxidation in the past. The changes in the δ34S isotope data for dissolved SO42- over the 1992-1996 period suggest a complex situation, indicating both sulphate reduction by sulphate

  12. Aespoe Hard Rock Laboratory. Temperature Buffer Test. Sensors data report (Period 030326-080701) Report No:12

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Aakesson, Mattias; Hoekmark, Harald (Clay Technology AB, Lund (Sweden))

    2008-07-01

    TBT (Temperature Buffer Test) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at understanding and modeling the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test is carried out in Aespoe HRL in a 8 meters deep and 1.75 m diameter deposition hole, with two heaters (3 m long, 0.6 m diameter), surrounded by a MX 80 bentonite buffer and a confining plug on top anchored with 9 rods. It was installed during spring 2003. Two buffer arrangements are being investigated: - The lower heater is surrounded by bentonite in the usual way, allowing the temperature of the bentonite to exceed 100 deg C locally. - The higher heater is surrounded by a ring of sand acting as thermal protection for the bentonite, the temperature of which is kept below 100 deg C. The canisters were heated with 1500 W power from day 15 to day 1171, when the power was raised to 1600 W. Around day 1700, the power was by steps raised in the lower heater to 2000 W and reduced in the upper heater to 1000 W. This report presents data from the measurements in the Temperature Buffer Test from 030326 to 080701 (26 March 2003 to 01 July 2008). The following measurements are made in the bentonite: Temperature is measured in 92 points, total pressure in 29 points, pore water pressure in 8 points and relative humidity in 35 points. Temperature is also measured by all gauges as an auxiliary measurement used for compensation. The following additional measurements are done: temperature is measured in 40 points in the rock, in 11 points on the surface of each canister and in 6 points inside each canister. The force on the confining plug is measured in 3 of the 9 rods and its vertical displacement is measured in three points. The water inflow and water pressure in the outer sand filter is also measured. Temperature and total pressure measurements

  13. Bacterial sulphate reduction and mixing processes at the Aespoe Hard Rock Laboratory indicated by groundwater delta34S isotope signatures

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, Bill (Geokema AB (Sweden))

    2011-04-15

    This report includes data mostly obtained from delta34S isotope measurements of groundwater at the Aespoe Island and one sampling from the Laxemar site, southeastern Sweden, during tunnel construction. Early sampling at Aespoe (up to 1992), before tunnel excavation, indicates a groundwater system with multiple sulphur sources. The isotope changes over time in the dissolved sulphate were studied during a sampling campaign in the monitoring phase from 1993 to 1995. A total of 88 samples were collected by SKB between 1992 and 1995 from core-drilled surface boreholes and from boreholes drilled in the tunnel (34 of these samples were collected from the tunnel boreholes). The results of the analyses have been the focus of discussion of the isotope changes with time in the dissolved sulphate (SO{sub 4}{sup 2-}). The results indicate that the sulphur isotope signatures in the dissolved sulphate of the groundwater and those from fracture-filling sulphides at Aespoe originate from multiple sulphur sources in the groundwater at Aespoe and Laxemar. The data may be grouped as follows: a) typically homogeneous marine signatures of dissolved SO{sub 4}{sup 2-} are observed, with delta34S values of approximately +21 per mille CDT at intermediate depths of approximately 100-250 m; b) dissolved sulphate in the groundwater at greater depths (below 600 m) with average values of approximately +10 per mille CDT; and c) a dissolved SO{sub 4}{sup 2-} originating from a mixture of these sulphur sources (100-600m), although there is a difference between a mixture and modification by reduction. Reduced sulphur with low delta34S values is also recorded in fracture-filling sulphides, with delta34S values of approximately 0 to -10 per mille CDT. This may contribute to small changes in the isotope signature of the dissolved SO{sub 4}{sup 2-}, probably by sulphide oxidation in the past. The changes in the delta34S isotope data for dissolved SO{sub 4}{sup 2-} over the 1992-1996 period suggest a

  14. Aespoe hard rock laboratory. Evaluation and conceptual modelling based on the pre-investigations 1986-1990

    International Nuclear Information System (INIS)

    The investigations have been grouped to several geometric scales under the disciplines of geology, geohydrology and groundwater chemistry, transport of solutes and mechanical stability. Geological mapping and geophysical measurements have been made both on a regional and on a site scale. On the site scale additional surface measurements, drilling of 35 percussion boreholes and 19 cored boreholes was made. The results of the geological investigations show that the Aespoe bedrock is a complex mixture between Smaaland granite, Aespoe diorite and fine grained granite. Hydraulic and chemical data was collected from existing well records within the Kalmar County. Hydraulic conductivity measurement and interference pumping tests were made in the core drilled holes and to some extent in the percussion holes. The hydraulic conductors are basically the fracture zones, but one of the most important is a NNW striking system of single fractures which is difficult to distinguish geologically. The chemical conditions of the groundwater and the fracture minerals form water bearing sections of the core drilled holes have been examined. Water samples were collected from percussion boreholes. The groundwater can be divided into three categories. Fresh water down to approximately 50 m depth. Mixed fresh and seawater 50-100 m, present and/or relict seawater 100-500 m and old (relict) seawater below a depth of 500 m. An important task in the evaluations is to set up 'conceptual models'. These models are the basis for calculation of the ambient groundwater situation and the way in which the hydrological regime will change during the excavation of the laboratory. In order to allow for different levels of detail the conceptual models are established on different scales. The geometrical scales chosen are 500 m, 50 m and 5 m. (au)

  15. Boring of full scale deposition holes at the Aespoe Hard Rock Laboratory. Operational experiences including boring performance and a work time analysis

    International Nuclear Information System (INIS)

    Thirteen experimental deposition holes similar to those in the present KBS-3 design have been bored at the Aespoe Hard Rock Laboratory, Oskarshamn, Sweden. The objective with the boring program was to test and demonstrate the current technique for boring of large vertical holes in granitic rock. Conclusions and results from this project is used in the planning process for the deposition holes that will be bored in the real repository for spent nuclear fuel. The boreholes are also important for three major projects. The Prototype Repository, the Canister Retrieval Test and the Demonstration project will all need full-scale deposition holes for their commissioning. The holes are bored in full scale and have a radius of 1.75 m and a depth of 8.5 m. To bore the holes an existing TBM design was modified to produce a novel type Shaft Boring Machine (SBM) suitable for boring 1.75 m diameter holes from a relatively small tunnel. The cutter head was equipped with two types of roller cutters: two row carbide button cutters and disc cutters. Removal of the cuttings was made with a vacuum suction system. The boring was monitored and boring parameters recorded by a computerised system for the evaluation of the boring performance. During boring of four of the holes temperature, stress and strain measurements were performed. Acoustic emission measurements were also performed during boring of these four holes. The results of these activities will not be discussed in this report since they are reported separately. Criteria regarding nominal borehole diameter, deviation of start and end centre point, surface roughness and performance of the machine were set up according to the KBS-3 design and were fulfilled with a fair margin. The average total time for boring one deposition hole during this project was 105 hours

  16. CRIEPI and SKB cooperation report No. 4. Numerical analysis for the effect of tunnel excavation on groundwater flow at Aespoe Hard Rock Laboratory, Sweden

    International Nuclear Information System (INIS)

    A numerical analysis was performed for the hydraulic impact of the tunnel excavated in crystalline rock for the construction of an underground research laboratory at Aespoe Island in Sweden. The subject of this study is to clarify the influence of excavation of the tunnel section from 700 m to 2,545 m. The size of the modeled region for the analysis is 1,800 meters from east to west and 2,000 meters from north to south so that it includes all the area of Aespoe Island. The lower boundary of the model is 1,000 meters under the ground. The existence of 19 major fracture zones was confirmed through geological survey and values of transmissivity, storativity and width were assigned to the fracture zones individually in the numerical model. On the other hand, uniform hydraulic characteristics were assigned to the whole rock formation except the fracture zones. Reduction of the hydraulic conductivities was taken into account for the grouted fracture zones. The analysis was performed by using a numerical code, FEGM, developed by CRIEPI for three-dimensional groundwater flow analysis. Drawdowns were observed during tunnel excavation at the boreholes excavated from the ground surface in Aespoe Island and were compared with the calculated results. The calculated drawdowns agreed will with the observed ones, indicating that the analytical method was proved effective. (author)

  17. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Dueck, Ann; Birgersson, Martin; Nilsson, Ulf; Hernan-Haakansson, Tania (Clay Technology AB, Lund (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden); Goeteborg Univ., Dept. of Cell and Molecular Biology, Goeteborg (Sweden)); Nilsson, Sara; Eriksen, Trygve E. (School of Chemical Science and Engineering, Nuclear chemistry, Royal Inst. of Tech., Stockholm (Sweden)); Rosborg, Bo (Rosborg Consulting, Nykoeping (Sweden))

    2009-11-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical

  18. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical properties

  19. KBS-3H - Excavation of two horizontal drifts at the Aespoe Hard Rock Laboratory during year 2004-2005. Work description, summary of results and experience

    International Nuclear Information System (INIS)

    SKB and Posiva Oy in Finland jointly study the possibility to develop a variant of the KBS-3 method for final disposal of spent nuclear fuel. The idea is to make serial deposition of canisters in long horizontal drifts instead of vertical deposition of single canisters in the deposition hole. The studies concerning the horizontal deposition alternative are conducted within the framework of a KBS-3H project, where certain demonstration activities are implemented. A key issue of the running project is to test the ability to excavate the horizontal deposition drifts. The objectives for this work are as follows: To show the feasibility of meeting the geometrical and other requirements; To construct two deposition drifts needed for the later project stages. One drift is needed to demonstrate that heavy load can be transported into the drift. One drift is needed to demonstrate that a plug (bulkhead) can be constructed by low-pH shotcrete; To evaluate the applicability of selected excavation methodologies for realistic repository conditions, and based on the experience in the project define need for technical developments/improvements. To meet the objectives, two deposition drifts were excavated at the Aespoe Hard Rock Laboratory during the period October 2004 to February 2005. One horizontal drift was 15 m in length and one 95 m in length. Both drifts were excavated to the diameter 1.85 m using horizontal push-reaming technology by adapting conventional raise-drilling equipment. The drifts were excavated in good rock conditions where no rock support or grouting was needed for feasible excavation or are needed to operate the drifts. SKB and Posiva have stringent geometrical requirements for the excavated drifts and the conclusions concerning compliance with the requirements are: Length: The project met this target. Two drifts were excavated, 15 m and 95 m respectively in accordance with the initial plan. Diameter: Actually it was not easy to measure the diameters of the

  20. Aespoe Hard Rock Laboratory. Aespoe Task Force on Engineered Barrier System. Modelling of THM-coupled processes for benchmark 2.2 with the code GeoSys/RockFlow

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Thomas; Kunz, Herbert (Federal Inst. for Geosciences and Natural Resources, Hannover (Germany))

    2010-02-15

    In 2004 the Swedish Nuclear Fuel and Waste Management Co. (SKB) initiated the project 'Task Force on Engineered Barrier Systems'. This project has the objective to verify the feasibility of modelling THM-coupled processes (task 1) and gas migration processes (task 2) in clay-rich buffer materials. The tasks are performed on the basis of appropriate benchmarks. This report documents the modelling results of the THM-benchmark 2.2 - the Canister Retrieval Test - using the code GeoSys/RockFlow. The Temperature Buffer Test which was performed in the immediate vicinity of the Canister Retrieval Test is included in the model. Especially the heat transport requires the handling of the problem in 3-D. Due to limitations imposed by post-processing different spatial discretisations of the model had to be used during the processing of the benchmark. The calculated temperatures agree well with measured data. Concerning hydraulic parameters the values of permeability and tortuosity were varied in the calculations. The time necessary to saturate the buffer is very sensitive to both of these values. In comparison to thermal and hydraulic processes the model only has limited capacity to predict the measured evolution of total pressure

  1. Use of excavation disturbance to acquire hydrochemical data for testing large length scale flow models. Plans for Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    Hydrochemical and hydrogeological investigations and data evaluation are central issues of the radioactive waste disposal site characterization and evaluation. The two disciplines are, in themselves, important but would give a deeper confidence in the long term safety and performance assessment if they could be found to be consistent. The Task 5 exercise is planned to make use of the draw-down of the Aespoe HRL tunnel to give data for comparison and consistency check of the hydrogeological groundwater flow models and the hydrochemical mixing-reaction models. In order to limit the task to conditions which can be observed, only the tunnel draw-down conditions are modeled. This simplifies the assumptions of boundary and initial conditions for the modellers. This modeling task, as well as previous ones, is carried out within the framework of the Aespoe Task Force for modeling of groundwater flow and transport of solutes. Active participation will be carried out by modellers from SKB, POSIVA BMBF, CRIEPI and PNC. (author)

  2. Analysis of rock stress and rock stress measurements with application to Aespoe HRL

    International Nuclear Information System (INIS)

    The process of choosing a site for a nuclear waste repository means that many aspects have to be taken into consideration. One of these is that the repository has to be mechanically stable for a long time. The mechanical stability of the rock is very difficult to determine. One of several factors, which determine the mechanical stability, is the virgin state of stress. The thesis project consists of two parts. In the first part the state of stress at Aespoe Hard Rock Laboratory had to be defined. This was done based on earlier rock stress measurements conducted during the years 1988 to 1997. Two different measurement techniques have been used, hydraulic fracturing and overcoring. During the overcoring two types of cells have been used, CSIRO HI-cell and a cell developed by the Swedish State Power Board (SSPB). In the second part of the project, investigation of the correlation between the stress and geological structures are made using numerical modelling tools such as FLAC, UDEC and 3DEC. The rock stress measurements using the hydraulic fracturing gave orientations of the horizontal stress that coincide with earlier hydraulic fracturing measurements conducted in Scandinavia. The magnitudes of rock stresses are slightly lower than the earlier reported stress magnitudes for the Scandinavian part of the earth crust. The rock stresses obtained from the overcoring resulted in higher stresses than what was predicted by the hydraulic fracturing measurements. However, the orientation of the maximum horizontal stresses coincides well between the two techniques. The orientation is also more or less constant with respect to increasing depth. The state of stress at Aespoe is defined by using the results from the hydraulic fracturing and the measurements conducted by SSPB-cell. The measurements from the SSPB-cell are used since these have a Poisson's ratio that corresponds well with the uniaxial tests of rock samples and since the measurements have been done at a distance from

  3. Strategy for a Rock Mechanics Site Descriptive Model. A test case based on data from the Aespoe HRL

    International Nuclear Information System (INIS)

    In anticipation of the SKB Site Investigations for radioactive waste disposal, an approach has been developed for the Rock Mechanics Site Descriptive Model. This approach was tested by predicting the rock mechanics properties of a 600 m x 180 m x 120 m rock volume at the Aespoe Hard Rock Laboratory (HRL) using limited borehole data of the type typically obtained during a site investigation. These predicted properties were then compared with 'best estimate' properties obtained from a study of the test rock volume using additional information, mainly tunnel data. The exercise was known as the Test Case, and is the subject of this Report. Three modelling techniques were used to predict the rock properties: the 'empirical approach' - the rock properties were estimated using rock mass classification schemes and empirical correlation formulae; the 'theoretical approach' - the rock properties were estimated using numerical modelling techniques; and the 'stress approach' - the rock stress state was estimated using primary data and numerical modelling. These approaches are described separately and respectively. Following an explanation of the context for the Test Case within the strategy for developing the Rock Mechanics Site Descriptive Model, conditions at the Aespoe HRL are described in Chapter 2. The Test Case organization and the suite of nine Protocols used to ensure that the work was appropriately guided and co-ordinated are described in Chapter 3. The methods for predicting the rock properties and the rock stress, and comparisons with the 'best estimate' properties of the actual conditions, are presented in Chapters 4 and 5. Finally, the conclusions from this Test Case exercise are given in Chapter 6. General recommendations for the management of this type of Test Case are also included

  4. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    International Nuclear Information System (INIS)

    -ductile shear zone striking along the drift dipping to the south-east. The zone is present in the experiment volume but is less pronounced there than in the rest of the drift. The zone is not assessed to give large enough changes in the geology to hazard the outcome of the experiment. The major concern has been the possibility of shearing along the zone in the pillar that would give stress re-distributions resulting in stresses too low to initiate brittle failure. The convergence measurements and the back calculation of those resulted in changes of the stress tensor and Young's modulus of the rock mass. The magnitudes and bearings of the principal stresses are in principal the same as the ones compiled from the extensive rock stress measurement made in the vicinity of the drift. However the numerical modelling resulted in changes of the dips. The new tensor has only horizontal and vertical stresses where the second principal stress is vertical. The derived Young's modulus is approximately 20% higher than what earlier has been predicted for the rock mass. The reason in this case is though likely that the convergence measurements were accidentally performed in a rock mass with extremely low fracture frequency. The few fractures likely give a more rigid rock mass than what's generally observed at Aespoe. The confirmation of the stress magnitudes by the back calculations is positive for the project. These stresses are concentrated by the drift shape and the large boreholes creating the pillar. A concern in the early part of the project was the risk that the in-situ stresses should be too low to increase the stresses high enough for initiation of spalling. This would have resulted in that very high temperatures would have been needed to expand the rock to initiate spalling which could have been hard to handle. The extensive laboratory tests are assessed to have given a good data set of the intact rock properties. The uniaxial and triaxial tests give similar results to what's earlier

  5. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle [Golder Associates AB, Uppsala (Sweden); Andersson, J. Christer; Magnor, Bjoern

    2004-03-01

    oxidized brittle-ductile shear zone striking along the drift dipping to the south-east. The zone is present in the experiment volume but is less pronounced there than in the rest of the drift. The zone is not assessed to give large enough changes in the geology to hazard the outcome of the experiment. The major concern has been the possibility of shearing along the zone in the pillar that would give stress re-distributions resulting in stresses too low to initiate brittle failure. The convergence measurements and the back calculation of those resulted in changes of the stress tensor and Young's modulus of the rock mass. The magnitudes and bearings of the principal stresses are in principal the same as the ones compiled from the extensive rock stress measurement made in the vicinity of the drift. However the numerical modelling resulted in changes of the dips. The new tensor has only horizontal and vertical stresses where the second principal stress is vertical. The derived Young's modulus is approximately 20% higher than what earlier has been predicted for the rock mass. The reason in this case is though likely that the convergence measurements were accidentally performed in a rock mass with extremely low fracture frequency. The few fractures likely give a more rigid rock mass than what's generally observed at Aespoe. The confirmation of the stress magnitudes by the back calculations is positive for the project. These stresses are concentrated by the drift shape and the large boreholes creating the pillar. A concern in the early part of the project was the risk that the in-situ stresses should be too low to increase the stresses high enough for initiation of spalling. This would have resulted in that very high temperatures would have been needed to expand the rock to initiate spalling which could have been hard to handle. The extensive laboratory tests are assessed to have given a good data set of the intact rock properties. The uniaxial and triaxial tests

  6. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2007 and March 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The experiment has been designed to simulate a disposal tunnel in a real deep repository environment for storage of high-level radioactive waste. The test consists of a 90 m long, 5 m diameter subhorizontal tunnel excavated in dioritic granite. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing.

  7. Hydrogeological pre-modelling exercises. Assessment of impact of the Aespoe Hard Rock Laboratory. Sensitivities of palaeo-hydrogeology. Development of a local near-surface Hydro-DFN for KLX09B-F. Site descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Numerical modelling has been used to investigate the potential impact of the Aespoe HRL on regional groundwater flow and hydro-geochemistry in the Laxemar study area. The numerical models have been adapted for this application from the ones use in the site-descriptive modelling (SDM) and SR-Can assessment modelling based on Laxemar version 1.2. In order to test the robustness of the simulation results, sensitivities were studied with respect to different flow boundary conditions and the hydraulic properties of the Quaternary deposits, particularly those beneath the sea around the Aespoe island. The simulations show that the Aespoe HRL has a local effect on the groundwater situation. Typically, in the simulations, the rock under the Aespoe island, the bays around it and the Aevroe area (mainly western part of the islands of Aevroe, Mjaelen and Haaloe) are influenced. In the sensitivity study, visualisations of the drawdown caused by the HRL tunnel system show small differences in the results for head versus flux top boundary conditions, little sensitivity to a change in the surface infiltration rate, but most sensitivity to the contact between the sea and the bedrock beneath the seabed sediments. For all simulation cases considered, results suggest that the Aespoe HRL has not been in operation sufficiently long to have affected the chemistry of samples collected at Laxemar and Simpevarp, though there is some possibility that Aevroe samples have been altered, at least for boreholes in the western part of Aevroe, Mjaelen and Haaloe. The distribution of flow and discharge areas around the bay at Aespoe is clearly affected by the HRL for all cases. Using the drawdown in percussion drilled boreholes around Aespoe as an interference test suggests that there is a partial reduction in the hydraulic contact between the sea and the groundwater system in the bedrock beneath. It is recommended that the conclusions about appropriate hydraulic properties for Quaternary sediments

  8. Hydrogeological pre-modelling exercises. Assessment of impact of the Aespoe Hard Rock Laboratory. Sensitivities of palaeo-hydrogeology. Development of a local near-surface Hydro-DFN for KLX09B-F. Site descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, Lee; Jackson, Peter; Joyce, Steve; Roberts, David; Shevelan, John; Swift, Ben (Serco Assurance, Harwell (GB)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (SE)); Hermanson, Jan; Oehman, Johan (Golders Associates (SE))

    2007-12-15

    Numerical modelling has been used to investigate the potential impact of the Aespoe HRL on regional groundwater flow and hydro-geochemistry in the Laxemar study area. The numerical models have been adapted for this application from the ones use in the site-descriptive modelling (SDM) and SR-Can assessment modelling based on Laxemar version 1.2. In order to test the robustness of the simulation results, sensitivities were studied with respect to different flow boundary conditions and the hydraulic properties of the Quaternary deposits, particularly those beneath the sea around the Aespoe island. The simulations show that the Aespoe HRL has a local effect on the groundwater situation. Typically, in the simulations, the rock under the Aespoe island, the bays around it and the Aevroe area (mainly western part of the islands of Aevroe, Mjaelen and Haaloe) are influenced. In the sensitivity study, visualisations of the drawdown caused by the HRL tunnel system show small differences in the results for head versus flux top boundary conditions, little sensitivity to a change in the surface infiltration rate, but most sensitivity to the contact between the sea and the bedrock beneath the seabed sediments. For all simulation cases considered, results suggest that the Aespoe HRL has not been in operation sufficiently long to have affected the chemistry of samples collected at Laxemar and Simpevarp, though there is some possibility that Aevroe samples have been altered, at least for boreholes in the western part of Aevroe, Mjaelen and Haaloe. The distribution of flow and discharge areas around the bay at Aespoe is clearly affected by the HRL for all cases. Using the drawdown in percussion drilled boreholes around Aespoe as an interference test suggests that there is a partial reduction in the hydraulic contact between the sea and the groundwater system in the bedrock beneath. It is recommended that the conclusions about appropriate hydraulic properties for Quaternary sediments

  9. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  10. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  11. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2009-03-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment.

  12. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    International Nuclear Information System (INIS)

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment

  13. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  14. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  15. Overview - Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  16. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    International Nuclear Information System (INIS)

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na+, Rb+ and Cs+) and alkaline earth metals (Ca2+, Sr2+ and Ba2+), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order Na+ in the order of (4-30)x10-6 m3/kg and for Cs+ in the range of (I-400)x10-3 m3/kg. The variations in sorption coefficients are due to differences in the composition of the geological material, contact time and particle size. Sorption is generally stronger for the Aespoe-diorite than for the fine-grained granite which is explained by the much higher concentration of biotite in Aespoe diorite than in fine-grained granite. In the altered material the biotite has been transformed to chlorite and a lower sorptivity is shown for those material compared to the fresh diorite and granite, respectively. Attempts to explain the sorption and desorption results to a surface sorption - diffusion model are presented. The diffusion results show that the tracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most representative when comparing batch sorption coefficients with sorption coefficients evaluated from the diffusion experiments. The

  17. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Byegaard, J.; Johansson, Henrik; Skaalberg, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    1998-11-01

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na{sup +}, Rb{sup +} and Cs{sup +}) and alkaline earth metals (Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+}), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order NaAespoe-diorite than for the fine-grained granite which is explained by the much higher concentration of biotite in Aespoe diorite than in fine-grained granite. In the altered material the biotite has been transformed to chlorite and a lower sorptivity is shown for those material compared to the fresh diorite and granite, respectively. Attempts to explain the sorption and desorption results to a surface sorption - diffusion model are presented. The diffusion results show that the tracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most

  18. Rock Mass Response to Coupled Mechanical Thermal Loading: Aespoe Pillar Stability Experiment, Sweden

    International Nuclear Information System (INIS)

    The geological disposal of nuclear waste, in underground openings and the long-term performance of these openings demand a detailed understanding of fundamental rock mechanics. A full scale field experiment: Aespoe Pillar Stability Experiment was conducted at a depth of 450 m in sparsely fractured granitic rock to examine the rock mass response between two deposition holes. An oval shaped tunnel was excavated parallel to the σ3 direction to provide access to the experiment and also provide elevated stress magnitudes in the floor. In the tunnel floor two 1.75-m diameter 6-m deep boreholes were excavated so that a 1-m thick pillar was created between them. In one of the holes a confinement pressure of 700 kPa was applied and in the other displacement transducers were installed. The pillar volume was monitored by an Acoustic Emission System. Spatially distributed thermocouples were used to monitor the temperature development as the pillar was heated by electrical heaters. The excavation-induced stress together with the thermal-induced stress was sufficient to cause the wall of the open borehole to yield. The temperature-induced stress was increased slowly to enable detailed studies of the rock mass yielding process. Once the rock mass loading response was observed, the rock mass was unloaded using a de-stress slotting technique. This thesis focuses on the in-situ study of the rock mass response to coupled mechanical thermal loading and thermal-mechanical unloading. The experiment, its design, monitoring and observations are thoroughly described. An estimate of the yielding strength of the rock mass is presented and compared with laboratory test and results from other rock mass conditions reported elsewhere in the open literature. General conclusions about the effect of the confining pressure and the observations from the unloading of the pillar are also presented. Important findings are that the yielding strength of the rock mass has been successfully determined, low

  19. Calcite fracture fillings as indicators of paleohydrology at the Aspo Hard Rock Laboratory, Sweden

    International Nuclear Information System (INIS)

    Isotopic compositions of carbon (δ13C), oxygen (δ16O) strontium (δ87Sr) in calcite fracture fillings are being used to reconstruct the source and evolution of the groundwater at Aespoe and Laxemar, at the Aespoe Hard Rock Laboratory (AEHRL), south-eastern Sweden. These calcites precipitated from groundwater in the fractured crystalline rocks at some time in the past, and δ13C, δ18O and δ87Sr values of the calcites reflect those of the source waters. The fracture fillings mark the pathways of past fluid movement so an understanding of their genesis is particularly important for understanding the paleohydrology in the area. The utility in applying the multiple-isotope approach to groundwater and fracture minerals derives from the fact that the different systems represent different processes. Studies of the groundwater chemistry suggest a very complicated history, however, the isotope data demonstrate that it is possible to postulate mixing of different groundwater members to explain the isotopic systematics of the calcite fracture fillings at Aespoe and Laxemar

  20. Aespoe HRL - Geoscientific evaluation 1997/1. Overview of site characterization 1986-1995

    International Nuclear Information System (INIS)

    Geological investigations for the Aespoe Hard Rock Laboratory in the region around Aespoe began in 1986. Aespoe was selected as the laboratory site in 1988 and construction of the underground facility started in october 1990. Construction of the laboratory was completed in the summer of 1995. This report gives a comprehensive compilation of the different investigations performed during the pre-investigation phase 1986-1990 and the excavation phase 1990-1995. The information is mainly compiled in CAD-generated maps, tables and illustrations in which the reader can gather information concerning the scope of work as well as references to more detailed reports for further study. 325 refs., 85 figs

  1. Rock stability considerations for siting and constructing a KBS-3 repository. Based on experiences from Aespoe HRL, AECL's URL, tunnelling and mining

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C.D. [Univ. of Alberta, Edmonton (Canada); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Soederhaell, J. [VBB VIAK AB, Stockholm (Sweden)

    2001-12-01

    Over the past 25 years the international nuclear community has carried out extensive research into the deep geological disposal of nuclear waste in hard rocks. In two cases this research has resulted in the construction of dedicated underground research facilities: SKB's Aespoe Hard Rock Laboratory, Sweden and AECL's Underground Research Laboratory, Canada. Both laboratories are located in hard rocks considered representative of the Fennoscandian and Canadian Shields, respectively. This report is intended to synthesize the important rock mechanics findings from these research programs. In particular the application of these finding to assessing the stability of underground openings. As such the report draws heavily on the published results from the SKB's ZEDEX Experiment in Sweden and AECL's Mine- by Experiment in Canada. The objectives of this report are to: 1. Describe, using the current state of knowledge, the role rock engineering can play in siting and constructing a KBS-3 repository. 2. Define the key rock mechanics parameters that should be determined in order to facilitate repository siting and construction. 3. Discuss possible construction issues, linked to rock stability, that may arise during the excavation of the underground openings of a KBS-3 repository. 4. Form a reference document for the rock stability analysis that has to be carried out as a part of the design works parallel to the site investigations. While there is no unique or single rock mechanics property or condition that would render the performance of a nuclear waste repository unacceptable, certain conditions can be treated as negative factors. Outlined below are major rock mechanics issues that should be addressed during the siting, construction and closure of a nuclear waste repository in Sweden in hard crystalline rock. During the site investigations phase, rock mechanics information will be predominately gathered from examination and testing of the rock core and

  2. Rock stability considerations for siting and constructing a KBS-3 repository. Based on experiences from Aespoe HRL, AECL's URL, tunnelling and mining

    International Nuclear Information System (INIS)

    Over the past 25 years the international nuclear community has carried out extensive research into the deep geological disposal of nuclear waste in hard rocks. In two cases this research has resulted in the construction of dedicated underground research facilities: SKB's Aespoe Hard Rock Laboratory, Sweden and AECL's Underground Research Laboratory, Canada. Both laboratories are located in hard rocks considered representative of the Fennoscandian and Canadian Shields, respectively. This report is intended to synthesize the important rock mechanics findings from these research programs. In particular the application of these finding to assessing the stability of underground openings. As such the report draws heavily on the published results from the SKB's ZEDEX Experiment in Sweden and AECL's Mine- by Experiment in Canada. The objectives of this report are to: 1. Describe, using the current state of knowledge, the role rock engineering can play in siting and constructing a KBS-3 repository. 2. Define the key rock mechanics parameters that should be determined in order to facilitate repository siting and construction. 3. Discuss possible construction issues, linked to rock stability, that may arise during the excavation of the underground openings of a KBS-3 repository. 4. Form a reference document for the rock stability analysis that has to be carried out as a part of the design works parallel to the site investigations. While there is no unique or single rock mechanics property or condition that would render the performance of a nuclear waste repository unacceptable, certain conditions can be treated as negative factors. Outlined below are major rock mechanics issues that should be addressed during the siting, construction and closure of a nuclear waste repository in Sweden in hard crystalline rock. During the site investigations phase, rock mechanics information will be predominately gathered from examination and testing of the rock core and mapping of the

  3. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  4. Swedish Hard Rock Laboratory first evaluation of preinvestigations 1986-87 and target area characterization

    International Nuclear Information System (INIS)

    SKB plans to site an underground research laboratory in the Simpevarp area. A regional survey started in 1986 and an extensive programme for geology, geohydrology and hydrochemistry was carried through. This report gives an evaluation of all available data gathered from the start of the project up to the drilling of core boreholes in some target areas in the autumn of 1987. A descriptive geological-tectonic model on a regional scale is presented that is intended to constitute a basis for the hydrogeological modelling work. Preliminary rock mass descriptions are also presented on a more detailed scale for some minor parts of the area. It is recommended that the island Aespoe is the principal target area for the continued work on the Swedish Hard Rock Laboratory. (orig.)

  5. Perception of the Hard Rock Brand by Czech University Students

    OpenAIRE

    Polák, Ivan

    2010-01-01

    The goal of this thesis is to understand perception of the Hard Rock brand in the Czech Republic among university students. Hard Rock Cafe Prague is a combination of a restaurant, bar, and rock club operated by the hospitality corporation Hard Rock International. The studied segment can be seen as a group of potential customers in long term, and this research should identify opportunities for growth of Czech guests. The thesis presents the process and results of Hard Rock brand research on th...

  6. Rock mechanical conditions at the Aespoe HRL. A study of the correlation between geology, tunnel maintenance and tunnel shape

    International Nuclear Information System (INIS)

    Maintenance records including scaling, shotcreting and bolting have been kept since the excavation start of Aespoe HRL 1990 together with records of groundwater flow and all other activities taking place in the tunnels. When the facility was constructed one objective was to limit the rock support as much as possible. The reason for this was that it should be possible to go back and easily study the exposed rock surface. Support during the operational phase has only been carried out where and when necessary. This type of maintenance and its location is documented in the digital database each time. The maintenance records have been compiled and areas requiring more maintenance than average noted. An interview has also been held with one of the miners conducting scaling and bolting in the tunnel. His experiences together with the study of the database maintenance records led to the selection of certain areas in the tunnel to be studied by numerical modelling. The probable reason for the need of additional maintenance in all areas, not only these numerically modelled, has been investigated. Almost all maintenance in the main tunnel both during construction and the operational phase has been located in the widened curves of the access tunnel. The maintenance is also located in areas containing veins or intrusions of Smaaland granite or fine-grained granite. These areas are often located in fracture zones of different sizes or show an increasing fracture frequency. The areas numerically modelled indicate stress concentrations or unloaded stress conditions. The stress concentrations are created by the geometry of the niches and side-tunnels in relation to the in situ stress field. The angle between the tunnel and the major principal stress has an impact on the need for maintenance. The areas with the largest angles towards the principal stress direction need more maintenance than the areas almost parallel to the major principal stress direction. The maintenance work in

  7. Mining technology development for hard rock excavation

    International Nuclear Information System (INIS)

    A research facility has been established in the granitic gneiss of the CSM Experimental Mine at Idaho Springs, Colorado, for the purpose of evaluating/developing mining, geologic and geotechnical procedures appropriate for use in establishing nuclear waste repositories in hard rock. An experimental room has been excavated using careful blasting procedures. The extent and magnitude of blast damage is being evaluated. Structural geology is being mapped to assess continuity

  8. Aespoe HRL - Geoscientific evaluation 1997/5. Models based on site characterization 1986-1995

    Energy Technology Data Exchange (ETDEWEB)

    Rhen, I. [ed.; Gustafsson, Gunnar [VBB Viak AB, Goeteborg (Sweden); Stanfors, R. [RS Consulting, Lund (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1997-10-01

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, geohydrology, hydrochemistry and rock mechanics. Predictions for the excavation phase were made prior to excavation of the laboratory which was started in the autumn of 1990. The predictions concern five key issues: lithology and geological structures, groundwater flow, hydrochemistry, transport of solutes and mechanical stability. During 1996 the results from the pre-investigations and the excavation of the Aespoe Hard Rock Laboratory were evaluated and were compiled in geological, mechanical stability, geohydrological, groundwater chemical and transport-of-solutes models. The model concepts and the models of 1996 are presented in this report. The model developments from the pre-investigation phase up to the models made 1996 are also presented briefly. 317 refs, figs, tabs.

  9. Aespoe HRL - Geoscientific evaluation 1997/5. Models based on site characterization 1986-1995

    International Nuclear Information System (INIS)

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, geohydrology, hydrochemistry and rock mechanics. Predictions for the excavation phase were made prior to excavation of the laboratory which was started in the autumn of 1990. The predictions concern five key issues: lithology and geological structures, groundwater flow, hydrochemistry, transport of solutes and mechanical stability. During 1996 the results from the pre-investigations and the excavation of the Aespoe Hard Rock Laboratory were evaluated and were compiled in geological, mechanical stability, geohydrological, groundwater chemical and transport-of-solutes models. The model concepts and the models of 1996 are presented in this report. The model developments from the pre-investigation phase up to the models made 1996 are also presented briefly

  10. Design for rock grouting based on analysis of grout penetration. Verification using Aespoe HRL data and parameter analysis

    International Nuclear Information System (INIS)

    the relationship between grout penetration and grouting time to derive theoretically based stop criteria for real grouting work. Verify the theory by using the field data from the grouting experiment at the 450 m level in the Aespoe HRL. Analyze the difference between the grouting result based on theoretically based stop criteria and that based on empirically based stop criteria. Evaluate the effect of variations in grouting parameters such as grouting pressure and grout materials. The further developed grouting theory includes models for increasing the grouting pressure and changing the grout mix and the capacity of grouting equipment. The theory focuses on deriving theoretically based stop criteria for real grouting work. The further developed theory was verified by comparing the calculated result with the measured result of the grouting experiment at the 450 m level of the Aespoe HRL. It was concluded that the further developed theory is well verified and is applicable to grouting design and analysis, even though there is still room for further improvement. The difference between the grouting results based on three types of stop criteria - one based on grout flow, one on grout take, and the third on grout penetration - has been analyzed for 1D and 2D flows. Three types of hypothetical rock masses with different permeabilities are used for the calculation. In both the 1D and 2D cases, great differences were found between the results derived from the three stop criteria. In general, grouted volume and grouting time for the 2D case were much higher than those for the 1D case. The results show the importance of choosing the theoretically based stop criteria based on the estimated flow dimension of the fracture system in order to avoid inadequate or uneconomical grouting. The parameter studies were conducted to show the effect of variation in grouting parameters. As a result of the parameter studies, it was found that the grouting time and the final grouting flow depend

  11. Aespoe HRL - Geoscientific evaluation 1997/2. Results from pre-investigation and detailed site characterization. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Rhen, I. [VBB Viak, Goeteborg (Sweden); Baeckbom, G. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)] [eds.; Gustafsson, Gunnar [VBB Viak, Goeteborg (Sweden) and Chalmers Univ. of Technology, Goeteborg (Sweden); Stanfors, R. [RS Consulting, Lund (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1997-05-01

    The work at Aespoe Hard rock laboratory provides an important scientific and technical basis for implementing and operating a future deep repository in Sweden. A milestone has now been reached with the completion of the pre investigation and construction phases at Aespoe HRL. The present data base at Aespoe HRL is one of the most comprehensive data bases in the world for crystalline rock properties, containing data from a large number of investigation methods from the surface down to 1700 m below ground level. Site characterization in conjunction with construction work has basically confirmed the pre-construction models. The site characterization has been a realistic `dress rehearsal` that is invaluable for planning and execution of surface and underground characterization of sites for the deep repository for spent nuclear fuel in Sweden. 502 refs, 114 figs, 30 tabs.

  12. Aespoe HRL - Geoscientific evaluation 1997/2. Results from pre-investigation and detailed site characterization. Summary report

    International Nuclear Information System (INIS)

    The work at Aespoe Hard rock laboratory provides an important scientific and technical basis for implementing and operating a future deep repository in Sweden. A milestone has now been reached with the completion of the pre investigation and construction phases at Aespoe HRL. The present data base at Aespoe HRL is one of the most comprehensive data bases in the world for crystalline rock properties, containing data from a large number of investigation methods from the surface down to 1700 m below ground level. Site characterization in conjunction with construction work has basically confirmed the pre-construction models. The site characterization has been a realistic 'dress rehearsal' that is invaluable for planning and execution of surface and underground characterization of sites for the deep repository for spent nuclear fuel in Sweden

  13. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    Science.gov (United States)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  14. Cutting capacity of PDC cutters in very hard rock

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed.Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite.The effects of the rough degree of rock surface,cutting angles,and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed.The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.

  15. Real-time monitoring of copper corrosion at the Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, Bo; Pan, Jinshan [Div. Corrosion Science, Royal Institute of Technology, Drottning Kristinas vaeg 51, SE - 100 44 Stockholm (Sweden); Eden, David [InterCorr International, Inc., 14503 Bammel-N Houston, Suite 300, Houston, TX 77014 (United States); Karnland, Ola [Clay Technology AB, Ideon Research Center, SE - 223 70 Lund (Sweden); Werme, Lars [Svensk Kaernbraenslehantering AB, P.O. Box 5864, SE - 102 40 Stockholm (Sweden)

    2004-07-01

    In Sweden the principal strategy for high-level radioactive waste disposal is to enclose the spent nuclear fuel in tightly sealed copper canisters that are embedded in bentonite clay about 500 m down in the Swedish bed-rock. Initially, a limited amount of air will be left in a repository after emplacement. The entrapped oxygen will be consumed through reactions with minerals in the rock and the bentonite and also through microbial activity. After the oxygen has been consumed in the repository, after a few hundred years at the very most, corrosion will be controlled completely by the supply of dissolved sulphide to the canister. The present work concerns the oxic period after emplacement. The main hypothesis is that the average corrosion rate of the canister under oxic conditions will be less than 7 {mu}m/year, and that pitting will only be possible under these conditions. The Aespoe Hard Rock Laboratory offers a realistic environment for different experiments and tests under the conditions that will prevail in a deep repository. Real-time monitoring of copper corrosion is presently performed with polarization resistance, harmonic distortion analysis and electrochemical noise techniques. The first two techniques are used to derive information regarding the general corrosion rate and the third to derive information regarding localized corrosion. In order to support these measurements at Aespoe, laboratory work is also performed at the Royal Institute of Technology in Stockholm using the very same corrosion monitoring equipment and also other equipment and techniques. Copper coupons are also exposed at Aespoe. Results from the work at Aespoe and in Stockholm are presented with an emphasis on the gained information concerning localized corrosion. The recorded corrosion rates at Aespoe are well below the value given above, and the recorded localization factors are interpreted as indicating only a slight tendency to local attack. (authors)

  16. A site scale analysis of groundwater flow and salinity distribution in the Aespoe area

    International Nuclear Information System (INIS)

    The objective of the study is to develop, calibrate and apply a numerical simulation model of the Aespoe area. An area of 1.8 x 1.8 km2, centred around the Aespoe Hard Rock Laboratory (HRL), gives the horizontal extent of the model. In the vertical direction the model follows the topography at the upper boundary and has a lower boundary at 1000 metres below sea level. The model is based on a mathematical model that includes equations for the Darcy velocities, mass conservation and salinity distribution. Gravitational effects are thus fully accounted for. A regional groundwater model was used to generate boundary conditions for vertical and bottom boundaries. Transmissivities of fracture zones and conductivities for the rock in between, as used in the model, are based on field data. An extensive calibration of the model is carried out, using data for natural conditions (i.e. prior to the construction of the Aespoe HRL), drawdowns from a pump test and data collected during the excavation of the tunnel. A satisfactory agreement with field data is obtained by the calibration. Main results from the model include vertical and horizontal sections of flow, salinity and hydraulic head distributions for natural conditions and for completed tunnel. A sensitivity study, where boundary conditions and material properties are modified, is also carried out. The model is also used to describe some characteristic features of the site like infiltration rates, flux statistics at a depth of 450 metres, salinity of inflows to the tunnel and flow and salinity distributions in fracture zones. The general conclusion of the study is that the model developed can simulate the conditions at Aespoe, both natural and with Aespoe HRL present, in a realistic manner

  17. Fiber Bragg grating strain sensor for hard rocks

    Science.gov (United States)

    Castro-Caicedo, Alvaro; Nieto-Callejas, María. J.; Torres, Pedro

    2015-09-01

    Strain is an important property to be measured in rock structures such as tunnels, slopes, dams, and mining. However, commercial surface mountable fiber Bragg grating (FBG) strain sensors are packaged in planar configuration, which is not appropriate for the irregular surface of the rocks since an unacceptable bonding layer fails to transfer the strain from the rock to the FBG. As a first approach to this problem, in this work we analyze packaged FBG sensors for cylindrical samples of hard rocks. A calibration process was carried out to evaluate the performance of the packaging and bonding layer as compared to electrical resistance strain gage methods. We show the importance of both packaging and bonding layer in FBG sensor technology for measuring strain in hard rocks.

  18. Aespoe modelling task force - experiences of the site specific flow and transport modelling (in detailed and site scale)

    International Nuclear Information System (INIS)

    The Aespoe Task Force on modelling of groundwater flow and transport of solutes was initiated in 1992. The Task Force shall be a forum for the organisations supporting the Aespoe Hard Rock Laboratory Project to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Much emphasis is put on building of confidence in the approaches and methods in use for modelling of groundwater flow and nuclide migration in order to demonstrate their use for performance and safety assessment. The modelling work within the Task Force is linked to the experiments performed at the Aespoe Laboratory. As the first Modelling Task, a large scale pumping and tracer experiment called LPT2 was chosen. This was the final part of the characterisation work for the Aespoe site before the construction of the laboratory in 1990. The construction of the Aespoe HRL access tunnel caused an even larger hydraulic disturbance on a much larger scale than that caused by the LPT2 pumping test. This was regarded as an interesting test case for the conceptual and numerical models of the Aespoe site developed during Task No 1, and was chosen as the third Modelling Task. The aim of Task 3 can be seen from two different perspectives. The Aespoe HRL project saw it as a test of their ability to define a conceptual and structural model of the site that can be utilised by independent modelling groups and be transformed to a predictive groundwater flow model. The modelling groups saw it as a means of understanding groundwater flow in a large fractured rock volume and of testing their computational tools. A general conclusion is that Task 3 has served these purposes well. Non-sorbing tracers tests, made as a part of the TRUE-experiments were chosen as the next predictive modelling task. A preliminary comparison between model predictions made by the Aespoe Task Force and the experimental results, shows that most modelling teams predicted breakthrough from

  19. Aespoe project. Hydrogeology and hydro-chemistry used to indicate present flow dynamics

    International Nuclear Information System (INIS)

    Major development in hydrogeological and hydrochemical groundwater modelling have been used independently to describe the present flow dynamics prior to and following the construction of the Aespoe Hard Rock Laboratory. Groundwater flow models used in calculating flow paths in the rock mass can be compared to the geochemical groundwater mixing and mass balance modelling in order to provide useful information on flow paths and transport times. However, there is still much work to be done to improve the integration between models on groundwater flow, groundwater chemistry and transport of solutes. (author)

  20. Isotopic systematics of saline waters at Aespoe and Laxemar, Sweden

    International Nuclear Information System (INIS)

    Saline waters have been encountered in deep bore holes and in the tunnel of the Aespoe Hard Rock Laboratory (AEHRL) in southern Sweden--a facility being developed to examine the suitability of crystalline rock for the construction of a geologic repository for nuclear waste. The deep waters are typically reducing, and their long-term chemical stability plays importantly in the concepts being developed for container design. Although deep, highly saline waters are common throughout the circum-Baltic region, their ultimate origin continues to be problematic. A deep drill hole (1.6 km) at Laxemar encountered a stratified ground-water system with an upper zone of fresh water overlying high saline brines below a compositional transition zone between 800 and 1050 m. In contrast, the ground-water system encountered in boreholes and in the tunnel at Aespoe, only 7 km from the Laxemar borehole, displays compositionally continuous gradients. The stable and radiogenic isotope systematics also differ markedly between these sites

  1. Electron accelerator for tunneling through hard rock

    International Nuclear Information System (INIS)

    Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented, with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

  2. Electron accelerator for tunneling through hard rock

    International Nuclear Information System (INIS)

    Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

  3. International cooperative research at Hard Rock Laboratory for high-level waste disposal (1999-2008). Validation of evaluation methods for groundwater environment and performance assessment methods

    International Nuclear Information System (INIS)

    CRIEPI has participated in the international joint research on in-situ experiments for geological disposal of high-level radioactive waste which is hosted by the Swedish Nuclear Fuel and Waste Management Co, SKB. CRIEPI's performance assessment methods and surveying techniques for site characterization were applied to in-situ or laboratory experiments and the following results were obtained. (1) It was shown that CRIEPI's numerical code for analyses of groundwater flow and solute transport, FEGM, enabled us to evaluate the solute transport through fracture network and the groundwater flow and seawater intrusion on a site scale accurately. (2) It was shown that CRIEPI's numerical code for coupling analysis of thermal, hydraulic and mechanical phenomena, LOSTUF, enabled us to predict the temperature distribution around waste packages, the intrusion of groundwater into buffer material and the swelling pressure of buffer material. (3) The residence-time distribution of groundwater at Aespoe Hard Rock Laboratory was evaluated on the basis of concentration of dissolved helium. And a new method for groundwater dating combining concentration of dissolved helium with 36Cl/Cl ratio was developed. (4) A laboratory experiment was conducted with the groundwater sampled at Aespoe HRL. The experiment showed that microbe had a major role on decrease of oxidation-reduction potential of groundwater. (5) Information on various advanced researches for in-situ experiments was collected and reflected in CRIEPI's research activities. (author)

  4. Performance Assessment of Hard Rock TBM and Rock Boreability Using Punch Penetration Test

    Science.gov (United States)

    Jeong, Ho-Young; Cho, Jung-Woo; Jeon, Seokwon; Rostami, Jamal

    2016-04-01

    Rock indentation tests are often called punch penetration tests and are known to be related to penetration rates of drilling equipment and hard rock tunnel boring machines (TBMs). Various indices determined from analysis of the force-penetration plot generated from indentation tests have been used to represent the drillability, boreability, and brittleness of rocks. However, no standard for the punch penetration test procedure or method for calculating the related indices has been suggested or adopted in the rock mechanics community. This paper introduces new indices based on the punch test to predict the performance of hard rock TBMs. A series of punch tests was performed on rock specimens representing six rock formations in Korea with different dimensions, i.e., the core specimens had different lengths and diameters. Of the indices obtained from the punch tests, the peak load index and mean load index showed good correlations with the cutting forces measured in full-scale linear cutting machine tests on the same rock types. The indices also showed good linear correlations with the ratio of uniaxial strength to Brazilian tensile strength, which indicates the brittleness of rock. The scale effect of using core specimens was investigated, and a preferred dimension for the punch test specimens is proposed. This paper also discusses the results of the punch test and full-scale rock cutting tests using LCM. The results of this study confirm that the proposed indices from the punch tests can be used to provide a reliable prediction of the cutting forces that act on a disc cutter. The estimated cutting forces can then be used for optimization of cutter-head design and performance prediction of hard rock TBMs.

  5. Sulphate reduction in the Aespoe HRL tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Geology; Laaksoharju, M. [ed.; Skaarman, C. [GeoPoint AB, Sollentuna (Sweden); Pedersen, K. [Goeteborg Univ. (Sweden). Dept. of Genetics, Microbiology and Molecular Biology; Rhen, I. [VBB Viak (Sweden); Tullborg, E.L. [Terralogica AB (Sweden); Wallin, B. [Geokema AB (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-12-01

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl{sup -} concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs.

  6. Sulphate reduction in the Aespoe HRL tunnel

    International Nuclear Information System (INIS)

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl- concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs

  7. Handling and final disposal of nuclear waste. Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The purpose of the Hard Rock Laboratory is to provide an opportunity for research and development in a realistic and undisturbed underground rock environment down to the depth planned for the future repository. The R and D work in the underground laboratory has the following main goals: To test the quality and appropriateness of different methods for characterizing the bedrock with respect to conditions of importance for a final repository. To refine and demonstrate methods for how to adapt a repository to the local properties of the rock in connection with planning and construction. And, finally, to collect material and data of importance for the safety of the future repository and for confidence in the quality of the safety assessments 13 figs, 3 tabs

  8. Interpretation of detailed ground magnetic data, resistivity and topographic data from Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Haakan (GeoVista AB (Sweden)); Wahlgren, Carl-Henric (Geological Survey of Sweden (Sweden))

    2010-12-15

    This report presents the interpretations of data from detailed ground magnetic and resistivity surveys, and also elevation data, from the island of Aespoe. The ground magnetic and geoelectric data were collected in 1988 as part of the pre-investigations that were carried out before the construction of the Aespoe Hard Rock Laboratory (HRL). The major aim of this work is to identify lineaments in the geophysical and topographic data. The lineaments that have been identified in the different data sets have been coordinated and subsequently linked together. The interpretation products of this work, in particular the linked lineaments, are important data sets and a prerequisite for the deterministic modelling of deformation zones at Aespoe. The magnetic and resistivity data processed and interpreted within the scope of this work show high quality; there are few outliers, physically reliable amplitude ranges, smooth and natural anomalies. The topographic grid is partly affected by noise or erroneous data that, for example, appears as distinct straight north-south trending lines in the maps. However, the artifacts have not had a significant effect on the interpretation of the elevation data. A total of 103 magnetic, 55 resistivity (geoelectric) and 85 topographic lineaments were identified. The coordination and linking procedure resulted in 37 final lineaments. The results of the lineament identifications based on the three data sets show a great deal of consensus; in location as well as in orientation of the lineaments. A large part of the lineaments have northeast/southwest orientations and are located in a low magnetic belt trending northeast-southwest across the central part of the Aespoe island. The c. 200-250 m wide low magnetic belt is interpreted to reflect the existence of a low-grade ductile shear zone. This belt is generally known as the Aespoe shear zone. The shear zone interpretation is also supported by the partly decreased resistivity, which indicates

  9. Aespoe HRL - Geoscientific evaluation 1997/4. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Hydrogeology, groundwater chemistry and transport of solutes

    Energy Technology Data Exchange (ETDEWEB)

    Rhen, I.; Gustafson, Gunnar [VBB Viak AB, Goeteborg (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1997-06-01

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, hydrogeology, hydrochemistry and rock mechanics. Prior to the excavation in 1990 predictions were made for the excavation phase concerning: geology, ground water flow and chemistry, transport of solutes and mechanical stability. This report presents a comparison between these predictions and the observations made during the excavation. Also, investigation methods for the 700-2874 m sections of the tunnel are evaluated. 157 refs, 190 figs, 37 tabs.

  10. Aespoe HRL - Geoscientific evaluation 1997/4. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Hydrogeology, groundwater chemistry and transport of solutes

    International Nuclear Information System (INIS)

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, hydrogeology, hydrochemistry and rock mechanics. Prior to the excavation in 1990 predictions were made for the excavation phase concerning: geology, ground water flow and chemistry, transport of solutes and mechanical stability. This report presents a comparison between these predictions and the observations made during the excavation. Also, investigation methods for the 700-2874 m sections of the tunnel are evaluated

  11. Modelling of nuclear explosions in hard rock sites

    International Nuclear Information System (INIS)

    This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock. In order to learn more about the response of hard rock to underground nuclear explosions, we have attempted to model the PILEDRIVER event. PILEDRIVER was fired on June 2, 1966 in the granite stock of Area 15 at the Nevada Test Site. The working point was at a depth of 462.7 m and the yield was determined to be 61 kt. Numerous surface, sub-surface and free-field measurements were made and analyzed by SRI. An attempt was made to determine the contribution of spall to the teleseismic signal, but proved unsuccessful because most of the data from below-shot-level gauges was lost. Nonetheless, there is quite a bit of good quality data from a variety of locations. We have been able to obtain relatively good agreement with the experimental PILEDRIVER waveforms. In order to do so, we had to model the granodiorite as being considerably weaker than ''good quality'' granite, and it had to undergo considerable weakening due to shock damage as well. In addition, the near-surface layers had to be modeled as being weak and compressible and as have a much lower sound speed than the material at depth. The is consistent with a fractured and jointed material at depth, and a weathered material near the surface

  12. Piping system subjected to seismic hard rock high frequencies

    International Nuclear Information System (INIS)

    Highlights: • A study of the influence of support gaps in the analysis of a piping system. • Piping system located within a nuclear power plant reactor containment building. • Piping system subjected to a seismic hard rock high-frequency load. • Comparison of low- and high-frequency seismic loads. • The influence on the stress response of piping and acceleration response of valves. - Abstract: This paper addresses the influence of support gaps in the analyses of a piping system when subjected to a seismic hard rock high-frequency load. The system is located within the reactor containment building of a nuclear power plant and is assessed to be susceptible to high-frequency loads. The stress response of the pipe and the acceleration response of the valves are evaluated for different support gap sizes. It is shown that the inclusion of the support gaps in the analyses reduces the stress response for almost all pipe elements. On the other hand, the acceleration response of the valves is not necessarily reduced by the consideration of the gaps

  13. Probabilistic Analysis of the Hard Rock Disintegration Process

    Directory of Open Access Journals (Sweden)

    K. Frydrýšek

    2008-01-01

    Full Text Available This paper focuses on a numerical analysis of the hard rock (ore disintegration process. The bit moves and sinks into the hard rock (mechanical contact with friction between the ore and the cutting bit and subsequently disintegrates it. The disintegration (i.e. the stress-strain relationship, contact forces, reaction forces and fracture of the ore is solved via the FEM (MSC.Marc/Mentat software and SBRA (Simulation-Based Reliability Assessment method (Monte Carlo simulations, Anthill and Mathcad software. The ore is disintegrated by deactivating the finite elements which satisfy the fracture condition. The material of the ore (i.e. yield stress, fracture limit, Young’s modulus and Poisson’s ratio, is given by bounded histograms (i.e. stochastic inputs which better describe reality. The results (reaction forces in the cutting bit are also of stochastic quantity and they are compared with experimental measurements. Application of the SBRA method in this area is a modern and innovative trend in mechanics. However, it takes a long time to solve this problem (due to material and structural nonlinearities, the large number of elements, many iteration steps and many Monte Carlo simulations. Parallel computers were therefore used to handle the large computational needs of this problem. 

  14. Aespoe Hard Rock Laboratory. The use of focused ion beams for structural characterisation of bentonite. A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Wegden, Marie; Kristiansson, Per (Division of Nuclear Physics, Lund Inst. of Technology (Sweden)); Svensson, Daniel; Sjoeland, Anders (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2009-07-01

    Bentonite clay is planned to be used in the KBS-3 concept for future nuclear high level waste (HLW) repository in Sweden. In the concept the spent nuclear fuel is placed in an iron insert, which is encapsulated in a copper canister. The copper canister is embedded in compacted bentonite and deposited at 500 m depth in granite bedrock. The compacted bentonite will act as a buffer material, giving mechanical support for the copper canister, reducing water movements and capturing potentially escaping radionuclides. Bentonite contains high amounts of smectite minerals (most common is montmorillonite), which are swelling clay minerals. The smectite minerals are layered and have the ability to store water in its structure. This is done by intercalating water between the layers and expanding the interlayer distance. The exceptional swelling capacity makes bentonite a suitable buffer material that works as a sealant and barrier. Heterogeneity in the material, compaction and in swelling may result in porosity, both on the nano- and micrometre scale. This may affect the permeability of the clay and may mediate the transport of radionuclides, cations and corrosion products. The aim of this work is to investigate the feasibility of using common ion beam techniques for structural characterisation of bentonite, including studying the mineral composition and the coarse porosity. The analytical techniques used were scanning transmission ion microscopy (STIM), particle-induced X-ray emission (PIXE) and elastic p-p scattering, performed at the Lund Nuclear Microprobe. On-axis STIM analysis was performed in order to measure and map the areal mass density of the sample. Since it was impossible to differentiate an increase in thickness from an area of higher mass density, as well as discerning depth variations, the STIM analysis was also performed in tomographic mode, in an attempt to obtain 3D structural information. The tomographic reconstruction showed that the bentonite had an interesting internal structure, with micrometre-sized features indicating both accessory minerals and potential pores. PIXE analysis was performed subsequently for investigation and mapping of the element distribution in the samples. From these element maps, the different mineral phases and regions suitable for further analysis could be identified. Finally hydrogen analysis was performed with the elastic p-p scattering method, in order to measure the water content in the sample. This method can be useful in further examinations of bentonite, if the variation in porosity is to be studied as a function of the degree of water saturation. This work demonstrates that, in a combination, PIXE, hydrogen analysis and microtomography with the STIM technique, can provide unique information on the internal structure and element distribution in a microscopic bentonite sample. Removal of water from the clay sample will change the clay structure and porosity due to the dehydration of the interlayer space and is hence problematic, however in this feasibility study this problem is neglected.

  15. Aespoe Hard Rock Laboratory. The use of focused ion beams for structural characterisation of bentonite. A feasibility study

    International Nuclear Information System (INIS)

    Bentonite clay is planned to be used in the KBS-3 concept for future nuclear high level waste (HLW) repository in Sweden. In the concept the spent nuclear fuel is placed in an iron insert, which is encapsulated in a copper canister. The copper canister is embedded in compacted bentonite and deposited at 500 m depth in granite bedrock. The compacted bentonite will act as a buffer material, giving mechanical support for the copper canister, reducing water movements and capturing potentially escaping radionuclides. Bentonite contains high amounts of smectite minerals (most common is montmorillonite), which are swelling clay minerals. The smectite minerals are layered and have the ability to store water in its structure. This is done by intercalating water between the layers and expanding the interlayer distance. The exceptional swelling capacity makes bentonite a suitable buffer material that works as a sealant and barrier. Heterogeneity in the material, compaction and in swelling may result in porosity, both on the nano- and micrometre scale. This may affect the permeability of the clay and may mediate the transport of radionuclides, cations and corrosion products. The aim of this work is to investigate the feasibility of using common ion beam techniques for structural characterisation of bentonite, including studying the mineral composition and the coarse porosity. The analytical techniques used were scanning transmission ion microscopy (STIM), particle-induced X-ray emission (PIXE) and elastic p-p scattering, performed at the Lund Nuclear Microprobe. On-axis STIM analysis was performed in order to measure and map the areal mass density of the sample. Since it was impossible to differentiate an increase in thickness from an area of higher mass density, as well as discerning depth variations, the STIM analysis was also performed in tomographic mode, in an attempt to obtain 3D structural information. The tomographic reconstruction showed that the bentonite had an interesting internal structure, with micrometre-sized features indicating both accessory minerals and potential pores. PIXE analysis was performed subsequently for investigation and mapping of the element distribution in the samples. From these element maps, the different mineral phases and regions suitable for further analysis could be identified. Finally hydrogen analysis was performed with the elastic p-p scattering method, in order to measure the water content in the sample. This method can be useful in further examinations of bentonite, if the variation in porosity is to be studied as a function of the degree of water saturation. This work demonstrates that, in a combination, PIXE, hydrogen analysis and microtomography with the STIM technique, can provide unique information on the internal structure and element distribution in a microscopic bentonite sample. Removal of water from the clay sample will change the clay structure and porosity due to the dehydration of the interlayer space and is hence problematic, however in this feasibility study this problem is neglected

  16. Numerical simulation for rheological characteristics of alternating distribution of soft and hard rock layers

    Institute of Scientific and Technical Information of China (English)

    HAN Bing; WANG Zhi-yin; DING Xiu-li; XU Ping

    2006-01-01

    The difficulty of selecting appropriate rheological model and parameters for the alternating distribution of soft and hard rock layers was often encountered due to the unhomogeneity, discontinuity and anisotropy of rock mass. The Burgers and generalized Kelvin models were applied to the soft and hard rock respectively and the rheological parameters were obtained based on the method of optimum separation. By using the simulated code FLAC3D, the stability of surrounding rocks of a certain underground plant was analyzed. The effect of surface load and weakening the parameters intensity of argillaceous and bioclastic interlayers between soft and hard rock on rheological behavior of layer composite rock mass was investigated. The results indicate that the rheological characteristics of soft and hard rock layer in composite rock mass can be described well with above two rheological models.

  17. MANAGEMENT AND TREATMENT OF WATER FROM HARD-ROCK MINES {ENGINEERING ISSUE}

    Science.gov (United States)

    This Engineering Issue document on treatment of mining waters is a practical guide to understanding and selecting technologies for the environmental management of waste materials and effluents at hard-rock mines. For the purposes of this discussion, hard-rock mining primarily ref...

  18. Research on the Hard-Rock Breaking Mechanism of Hydraulic Drilling Impact Tunneling

    OpenAIRE

    Risheng Long; Shaoni Sun; Zisheng Lian

    2015-01-01

    In order to realize the rapid hard-rock tunneling in a safe, highly effective, and economic manner, the hydraulic drilling impact hard-rock tunneling (HDIHT) technology and method were introduced based on the theories of rock mechanics and hydraulic impact. The key parameters, including drilling radius and impact distance, were researched to reveal the stress behavior during HDIHT process. The Von Mises equivalent stress and its principal stress components were analyzed, and the breaking mech...

  19. Pillar Design in the Hard Rock Mines of South Africa

    Directory of Open Access Journals (Sweden)

    D.F. Malan

    2012-12-01

    Full Text Available This paper gives an overview of the difficulties associated with the design of hard rock pillars in South African mines. Recent examples of large scale pillar collapses in South Africa suggest that these were caused by weak partings which traversed the pillars. Currently two different methods are used to determine the strength of pillars, namely, empirical equations derived from back analyses of failed and stable cases and numerical modeling tools using appropriate failure criteria. It is illustrated in the paper that both techniques have their limitations and additional work is required to obtain a better understanding of pillar strength.Empirical methods based on observations of pillar behaviour in a given geotechnical setting are popular and easy to use, but care should be exercised that the results are not inappropriately extrapolated beyond the environment in which they are established. An example is the Hedley and Grant formula (derived for the Canadian uranium mines that has been used for many years in the South African platinum and chrome mines (albeit with some adaptation of the K-value. Very few collapses have been reported in South Africa for layouts designed using this formula, suggesting that in some cases it might yield estimates of pillar strength that are too conservative.As an alternative, some engineers strongly advocate the use of numerical techniques to determine pillar strength. A close examination unfortunately reveals that these techniques also rely on many assumptions. An area where numerical modeling is invaluable, however, is to determine pillar stresses accurately and to study specific pillar failure mechanisms, such as the influence of weak partings on pillar strength.

  20. Groundwater prospecting, drilling and well construction in hard rocks in semi-arid regions: an overview

    OpenAIRE

    Chambel, António

    2012-01-01

    In semi-arid and arid areas rock weathering is normally much less deep that in rainy areas. So, rocks tend to be more near the topographic surface. These climatic conditions also generate much less vegetation, which in all the cases clearly favours a direct observation of rock condition, fracturing or weathering. By other side, aquifers in hard rocks present specificities in relation to water presence and movement that implies a different approach when dealing with groundwater prospecting....

  1. Experimental study on large diameter drilling in hard rock annular coring

    Institute of Scientific and Technical Information of China (English)

    Yinzhu WU; Guochun YANG; Wenchen WANG

    2008-01-01

    Based on analyzing method of large diameter hard rock drilling at home and abroad, the authors proposed a set of drilling of large diameter hard rock annular coring in low energy consumption, low cost and high efficiency. The prototype of drilling tools was designed and was made. The experimental result of the prototype indicates that this plan and technology are feasible and reach the anticipated object of design. A set of drilling tools has been offered for the constructs of large diameter hard rock coring.

  2. Comparison of the SKI, SKB, and SKN geological and structural models of the Aespoe area

    Energy Technology Data Exchange (ETDEWEB)

    Tiren, S.A. [Geosigma AB, Uppsala (Sweden)

    1996-06-01

    Three sets of geological and structural models produced by three different groups are compared. The same set of basic data has been available to each of the groups. The models, all of which are 2 by 2 km by 1 km deep - or smaller, are based entirely on surface-based investigations. The modelled area is centered on the island of Aespoe, where SKB has built the Hard Rock Laboratory (HRL) in plutonic bedrock at a depth of 500 m. SKB (Swedish Nuclear Fuel and Waste Management Co) has recorded the basic data during the period 1986 to 1991, before starting the underground work. One of the main tasks in the SKB characterization of the HRL rock mass was to predict which of the geological structures will have the greatest rock-mechanical and hydraulic significance. The National Board for Spent Nuclear Fuel (SKN) constructed alternative models in 1992 to verify the SKB model. However, the SKN models were subsequently modified and converted into a hydrogeological model. The Swedish Nuclear Inspectorate (SKI) chose Aespoe as a hypothetical site for storage of nuclear waste in their SITE 94 project. The objective of the project is to assist SKI in their future review of SKB`s application for a license to dispose of spent nuclear fuel underground. The agreement of the three models is found to be best where the density of information is greatest. The main difference between the two geological models is related to the inferred effects of block faulting on the rock type distribution. The correlation of moderately to gently inclined zones between the models is relatively poor at depth. 46 refs, 30 figs, 18 tabs.

  3. Comparison of the SKI, SKB, and SKN geological and structural models of the Aespoe area

    International Nuclear Information System (INIS)

    Three sets of geological and structural models produced by three different groups are compared. The same set of basic data has been available to each of the groups. The models, all of which are 2 by 2 km by 1 km deep - or smaller, are based entirely on surface-based investigations. The modelled area is centered on the island of Aespoe, where SKB has built the Hard Rock Laboratory (HRL) in plutonic bedrock at a depth of 500 m. SKB (Swedish Nuclear Fuel and Waste Management Co) has recorded the basic data during the period 1986 to 1991, before starting the underground work. One of the main tasks in the SKB characterization of the HRL rock mass was to predict which of the geological structures will have the greatest rock-mechanical and hydraulic significance. The National Board for Spent Nuclear Fuel (SKN) constructed alternative models in 1992 to verify the SKB model. However, the SKN models were subsequently modified and converted into a hydrogeological model. The Swedish Nuclear Inspectorate (SKI) chose Aespoe as a hypothetical site for storage of nuclear waste in their SITE 94 project. The objective of the project is to assist SKI in their future review of SKB's application for a license to dispose of spent nuclear fuel underground. The agreement of the three models is found to be best where the density of information is greatest. The main difference between the two geological models is related to the inferred effects of block faulting on the rock type distribution. The correlation of moderately to gently inclined zones between the models is relatively poor at depth

  4. IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER

    Directory of Open Access Journals (Sweden)

    Trpimir Kujundžić

    2008-12-01

    Full Text Available The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher.

  5. Sorption of redox sensitive actinides onto granite and altered material from AESPOE HRL

    International Nuclear Information System (INIS)

    Sorption experiments with redox sensitive actinide elements such as Pu, Np and U as well as the fission product Tc are performed onto fracture filling material, which are obtained from Aespoe Hard Rock Laboratory. Migration experiments using these elements showed a complex retention pattern along the flow path. For this reason a new SEM/EDX analysis technique was applied for identification retaining mineral phases. From previous investigations, it is known that Np(V) is retained by reduction to Np(IV) in the presence of Fe(II) minerals. Sorption of U is also strongly correlated with the occurrence of Fe oxide phases. The retention mechanism onto Fe(II) phases is evaluated for Np but is not yet confirmed for U and Tc. These tracer concentrations were too low along the flow path. Additionally, the internal surface areas of the fracture play a dominating role for retaining the redox sensitive radionuclides

  6. Designing the ejector pellet impact drill bit for hard and tough rock drilling

    International Nuclear Information System (INIS)

    There are many types of ejector pellet impact drill bit providing impact rock drilling. Basic types of drill strings have been regarded, the essential requirements for the most efficient facilities to drill hard and tough rocks are formulated. With regard to these requirements, the ejector pellet impact drill bit design appropriate for operating under given conditions has been proposed

  7. Hydrogeologic controls on radon-222 in the hard rock fractured aquifer of Bangalore, Karnataka

    International Nuclear Information System (INIS)

    The objective of the present study is to evaluate the distribution of radon in hard rock fractured aquifer in Bangalore. Radon concentrations are known to be high in the granitic rock of this area and this study attempts to enhance our understanding of the distribution of radon in the highly fractured and non fractured granitic aquifers. Hydrogeologically, the area is underlain by granite, migmatite, granodiorite and gneiss rock

  8. Dynamic design method for deep hard rock tunnels and its application

    Directory of Open Access Journals (Sweden)

    Xia-Ting Feng

    2016-08-01

    Full Text Available Numerous deep underground projects have been designed and constructed in China, which are beyond the current specifications in terms of scale and construction difficulty. The severe failure problems induced by high in situ stress, such as rockburst, spalling, damage of deep surrounding rocks, and time-dependent damage, were observed during construction of these projects. To address these problems, the dynamic design method for deep hard rock tunnels is proposed based on the disintegration process of surrounding rocks using associated dynamic control theories and technologies. Seven steps are basically employed: (i determination of design objective, (ii characteristics of site, rock mass and project, and identification of constraint conditions, (iii selection or development of global design strategy, (iv determination of modeling method and software, (v preliminary design, (vi comprehensive integrated method and dynamic feedback analysis, and (vii final design. This dynamic method was applied to the construction of the headrace tunnels at Jinping II hydropower station. The key technical issues encountered during the construction of deep hard rock tunnels, such as in situ stress distribution along the tunnels, mechanical properties and constitutive model of deep hard rocks, determination of mechanical parameters of surrounding rocks, stability evaluation of surrounding rocks, and optimization design of rock support and lining, have been adequately addressed. The proposed method and its application can provide guidance for deep underground projects characterized with similar geological conditions.

  9. Incoherent SSI Analysis of Reactor Building using 2007 Hard-Rock Coherency Model

    International Nuclear Information System (INIS)

    Many strong earthquake recordings show the response motions at building foundations to be less intense than the corresponding free-field motions. To account for these phenomena, the concept of spatial variation, or wave incoherence was introduced. Several approaches for its application to practical analysis and design as part of soil-structure interaction (SSI) effect have been developed. However, conventional wave incoherency models didn't reflect the characteristics of earthquake data from hard-rock site, and their application to the practical nuclear structures on the hard-rock sites was not justified sufficiently. This paper is focused on the response impact of hard-rock coherency model proposed in 2007 on the incoherent SSI analysis results of nuclear power plant (NPP) structure. A typical reactor building of pressurized water reactor (PWR) type NPP is modeled classified into surface and embedded foundations. The model is also assumed to be located on medium-hard rock and hard-rock sites. The SSI analysis results are obtained and compared in case of coherent and incoherent input motions. The structural responses considering rocking and torsion effects are also investigated

  10. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    Science.gov (United States)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  11. Research on definition of hard rock shear wave velocity of site for nuclear power plant

    International Nuclear Information System (INIS)

    Background: The definition of hard rock shear wave velocity is one of the most critical issues in the work of site selection. Purpose: To make a definition of hard rock site on which the model can be assumed as fixed-base condition, a series of research had been done. Several possible hard rock site soil models were developed. Methods: Shear wave velocity of hard rock had been assumed from 1100 m/s to 3200 m/s. For each case, free field analysis and soil structure analysis had been performed. And responses in soil and key nodes of structure were compared. Results: In free field analysis, responses of models that shear wave velocity below 2400 m/s decreased a lot. In SSI analysis, structure responses didn't change much when shear wave velocity was above 2400 m/s. Conclusions: 2400 m/s was the lowest shear wave velocity for hard rock site for fixed-base assumption. (authors)

  12. An Estimation Method of Stress in Soft Rock Based on In-situ Measured Stress in Hard Rock

    Institute of Scientific and Technical Information of China (English)

    LI Wen-ping; LI Xiao-qin; SUN Ru-hua

    2007-01-01

    The law of variation of deep rock stress in gravitational and tectonic stress fields is analyzed based on the Hoek-Brown strength criterion. In the gravitational stress field, the rocks in the shallow area are in an elastic state and the deep, relatively soft rock may be in a plastic state. However, in the tectonic stress field, the relatively soft rock in the shallow area is in a plastic state and the deep rock in an elastic state. A method is proposed to estimate stress values in coal and soft rock based on in-situ measurements of hard rock. Our estimation method relates to the type of stress field and stress state. The equations of rock stress in various stress states are presented for the elastic, plastic and critical states. The critical state is a special stress state, which indicates the conversion of the elastic to the plastic state in the gravitational stress field and the conversion of the plastic to the elastic state in the tectonic stress field. Two cases studies show that the estimation method is feasible.

  13. The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

    Directory of Open Access Journals (Sweden)

    Hehua Zhu

    2015-01-01

    Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

  14. Outcrop Groundwater Prospecting, Drilling, and Well Construction in Hard Rocks in Semi-arid Regions

    OpenAIRE

    Chambel, António

    2014-01-01

    This chapter presents some recommendations for prospecting, drilling and well construction in hard rocks in semi-arid regions. Considering that these conditions are present in many countries where technology is not always available, the chapter concentrates on the most basic and simple methods to plan where best to drill and maximize success through the direct observation of rock types, weathering and fracturing. The advantage for the geologist and hydrogeologist in an arid or semi-arid envir...

  15. Choice of grouting method for jointed hard rock based on sealing time predictions

    OpenAIRE

    Dalmalm, Thomas

    2004-01-01

    This thesis concerns subjects related to the choice of agrouting method in a jointed hard rock mass. By calculating thetotal sealing time to reach the requested sealing level,different grouting methods could be compared and the mostfavourable chosen. A methodology, to calculate the sealing time for differentgrouting methods in different rock masses has been developed.Five main activities are included in the methodology; drilling,grouting, waiting, probing and re-grouting, which to differingde...

  16. Dynamics of ultrasonic percussive drilling of hard rocks

    Science.gov (United States)

    Wiercigroch, M.; Wojewoda, J.; Krivtsov, A. M.

    2005-02-01

    Ultrasonic percussive drilling with diamond-coated tools has been extensively studied under laboratory conditions on rocks such as sandstone, limestone, granite and basalt, in order to investigate the applicability of this technique to downhole drilling. An experimental set-up, a programme of work and example results are presented. The studies showed that an introduction of high-frequency axial vibration significantly enhances drilling rates compared to the traditional rotary type method. It has been found out that the material removal rate (MRR) as a function of static load has at least one maximum. Looking at the time histories of the measured drilling force, strong nonlinear effects have been observed, which were explained using simple nonlinear models. Among them, pure impact and impact with dry friction oscillators were used to provide an insight into the complex dynamics of ultrasonic percussive drilling. It is postulated that the main mechanism of the MRR enhancement is associated with high amplitudes of forces generated by impacts. Novel procedures for calculating MRR are proposed, explaining an experimentally observed fall of MRR at higher static loads.

  17. Groundwater Resources Potential in Hard Rock Terrain: A Multivariate Approach.

    Science.gov (United States)

    Earon, Robert; Dehkordi, S Emad; Olofsson, Bo

    2015-01-01

    Groundwater resources are limited and difficult to predict in crystalline bedrock due to heterogeneity and anisotropy in rock fracture systems. Municipal-level governments often lack the resources for traditional hydrogeological tests when planning for sustainable use of water resources. A new methodology for assessing groundwater resources potential (GRP) based on geological and topographical factors using principal component analysis (PCA) and analysis of variance (ANOVA) was developed and tested. ANOVA results demonstrated statistically significant differences in classed variable groups as well as in classed GRP scores with regard to hydrogeological indicators, such as specific capacity (SC) and transmissivity. Results of PCA were used to govern the weight of the variables used in the prediction maps. GRP scores were able to identify 79% of wells in a verification dataset, which had SC values less than the total dataset median. GRP values showed statistically significant correlations using both parametric (using transformed datasets) and non-parametric methods. The method shows promise for municipal or regional level planning in crystalline terrains with high levels of heterogeneity and anisotropy as a hydrogeologically and statistically based tool to assist in assessing groundwater resources. The methodology is executed in a geographic information systems environment, and uses often readily available data, such as geological maps, feature maps and topography, and thus does not require expensive and time-consuming aquifer tests. PMID:25214009

  18. Impact of global climate change on transmissivity of shallow hard-rock aquifers

    Czech Academy of Sciences Publication Activity Database

    Hrkal, Z.; Kobr, M.; Nedvědová, E.; Tesař, Miroslav; Vilhelm, Z.

    Wroclav : Wydawnictwo Uniwersytetu Wroclawskiego, 2007 - (Marszalek, H.; Chudy, K.), s. 191-203 ISBN 978-83-229-2912-4 Grant ostatní: GA ČR(CZ) GA205/05/0177 Institutional research plan: CEZ:AV0Z20600510 Keywords : climate change * transmissivity * hard-rock aquifer Subject RIV: DA - Hydrology ; Limnology

  19. Aespoe HRL. Experiences of blasting of the TASQ tunnel

    International Nuclear Information System (INIS)

    A new tunnel was developed at the Aespoe Hard Rock Laboratory (AHRL) during the spring and summer 2003. The tunnel was specially designed for a rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). In this pillar experiment there was a high demand to initiate high in-situ stresses and therefore the tunnel was designed with a large height/ width ratio and with a circular floor. There were high requirements on bore hole precision and of a minimized EDZ (Excavation damaged zone) in the pillar area. This included a maximum borehole deviation of 10 mm/m, a maximum overbreak due to the lookout angle of 0.3 m and an EDZ of 0.3 m. To make a charge control feasible cartridged explosives was prescribed. The initiation was made with Nonel. The last three rounds used electronic initiation to enable studies of possibility to further reduce the EDZ. The collar of the tunnel was very close to installations and shaft and it was very important to avoid fly-rock and vibrations. Special types of stemming were used as well as steel plates and rubber mats. The excavation works was divided in three different phases. The first phase of the tunnel was an ordinary 26 m2 tunnel. After approximately 30 m a ramp separated the tunnel section into a top heading and a bench, total 33 m2. After the last top heading round was excavated and the roof had been reinforced with fibre reinforced shotcrete the bench was taken out with horizontal holes as the third phase. The drilling precision was very good and 95% of all half-pipes fulfilled the demands. The total amount of visible half-pipes in the APSE-tunnel was high and indicated a successful smooth blasting. The EDZ was examined further by cutting slots in the wall and roof. Existing cracks appear very clearly when a dye penetrant is sprayed on the cleaned surface. A typical crack pattern consists of blast cracks, induced cracks (cracks from the distressing caused by blasting) and natural cracks. The maximum crack length in the

  20. Aespoe HRL. Experiences of blasting of the TASQ tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Mats [Swebrec, Luleaa (Sweden); Niklasson, Bengt [Skanska Teknik, Stockholm (Sweden); Wilson, Lasse [Skanska Stora Projekt, Stockholm (Sweden); Andersson, Christer; Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-11-01

    A new tunnel was developed at the Aespoe Hard Rock Laboratory (AHRL) during the spring and summer 2003. The tunnel was specially designed for a rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). In this pillar experiment there was a high demand to initiate high in-situ stresses and therefore the tunnel was designed with a large height/ width ratio and with a circular floor. There were high requirements on bore hole precision and of a minimized EDZ (Excavation damaged zone) in the pillar area. This included a maximum borehole deviation of 10 mm/m, a maximum overbreak due to the lookout angle of 0.3 m and an EDZ of 0.3 m. To make a charge control feasible cartridged explosives was prescribed. The initiation was made with Nonel. The last three rounds used electronic initiation to enable studies of possibility to further reduce the EDZ. The collar of the tunnel was very close to installations and shaft and it was very important to avoid fly-rock and vibrations. Special types of stemming were used as well as steel plates and rubber mats. The excavation works was divided in three different phases. The first phase of the tunnel was an ordinary 26 m{sup 2} tunnel. After approximately 30 m a ramp separated the tunnel section into a top heading and a bench, total 33 m{sup 2}. After the last top heading round was excavated and the roof had been reinforced with fibre reinforced shotcrete the bench was taken out with horizontal holes as the third phase. The drilling precision was very good and 95% of all half-pipes fulfilled the demands. The total amount of visible half-pipes in the APSE-tunnel was high and indicated a successful smooth blasting. The EDZ was examined further by cutting slots in the wall and roof. Existing cracks appear very clearly when a dye penetrant is sprayed on the cleaned surface. A typical crack pattern consists of blast cracks, induced cracks (cracks from the distressing caused by blasting) and natural cracks. The maximum crack

  1. Hard rock hydrogeology in the construction of the ONKALO underground rock characterisation facility

    International Nuclear Information System (INIS)

    The spent fuel from the Finnish nuclear power plants will be disposed of at Olkiluoto in the municipality of Eurajoki. A rock facility, named as ONKALO, shall be designed and constructed by Posiva Oy to enable further characterisation and research of the host rock without jeopardising the favourable properties of the repository site. Posiva has organised a project 'Control of Groundwater' to identify and develop the ways to control the foreseen disturbances caused by groundwater inflow into the ONKALO and the deep repository. The project has resulted in a preliminary conception of the amount and the distribution of the water inflow as well as of grouting conditions at Olkiluoto. The main technical way foreseen to control the leakages is pregrouting of the rock. Since the target inflows are very low and there are limitations for activities and materials, the problems in water-inflow control culminate in the very small fracture apertures and high hydrostatic pressure in the deep bedrock. (orig.)

  2. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    International Nuclear Information System (INIS)

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  3. Ion sorption onto hydrous ferric oxides: Effect on major element fluid chemistry at Aespoe, Sweden

    International Nuclear Information System (INIS)

    The observed variability of fluid chemistry at the Aespoe Hard Rock Laboratory is not fully described by conservative fluid mixing models. Ion exchange may account for some of the observed discrepancies. It is also possible that variably charged solids such as oxyhydroxides of Fe can serve as sources and sinks of anions and cations through surface complexation. Surface complexation reactions on hydrous ferric oxides involve sorption of both cations and anions. Geochemical modeling of the surface chemistry of hydrous ferric oxides (HFOs) in equilibrium with shallow HBH02 and deep KA0483A waters shows that HFOs can serve as significant, pH-sensitive sources and sinks for cations and anions. Carbonate sorption is favored especially at below-neutral pH. A greater mass of carbonate is sorbed onto HFO surfaces than is contained in the fluid when 10 g goethite, used as a proxy for HFOs, is in contact with 1 kg H2O. The masses of sorbent required to significantly impact fluid chemistry through sorption/desorption reactions seem to be reasonable when compared to the occurrences of HFOs at Aespoe. Thus, it is possible that small changes in fluid chemistry can cause significant releases of cations or anions from HFOs into the fluid phase or, alternately, result in uptake of aqueous species onto HFO surfaces. Simulations of the mixing of shallow HBH02 and native KA0483A waters in the presence of a fixed mass of goethite show that surface complexation does not cause the concentrations of Ca, Sr, and SO4 to deviate from those that are predicted using conservative mixing models. Results for HCO3 are more difficult to interpret and cannot be addressed adequately at this time

  4. Theoretical Basis in Regression Model Based Selection of the Most Cost Effective Parameters of Hard Rock Surface Mining

    OpenAIRE

    Antipas T. S. Massawe; Karim R. Baruti; Paul S. M. Gongo

    2011-01-01

    What determines selection of the most cost effective parameters of hard rock surface mining is consideration of all alternative variants of mine design and the conflicting effect of their parameters on cost. Consideration could be realized based on the mathematical model of the cumulative influence of rockmass and mine design variables on the overall cost per ton of the hard rock drilled, blasted, hauled and primary crushed. Available works on the topic mostly dwelt on four processes of hard ...

  5. Occurrence of the radionuclides in groundwater of crystalline hard rock regions of central Tamil Nadu, India

    International Nuclear Information System (INIS)

    A study was conducted to understand the occurrence of the radionuclides in groundwater of crystalline hard rock region. Samples were collected to analyze major cations, anions, U, 222Rn and stable isotopes of oxygen, hydrogen. It was inferred that few samples have U and 222Rn concentrations higher than the permissible limit of drinking water standard. High degree of weathering of granitic rocks and long contact time of groundwater with the aquifer matrix could be the reason for enhanced U and 222Rn levels in groundwater. The association of U with SO4 also proves that there exists anthropogenic influence in groundwater composition. (author)

  6. Numerical analysis for heating and infiltration test at model deposition hole in underground hard rock laboratory

    International Nuclear Information System (INIS)

    Various insitu tests for the safety disposal of radioactive waste are conducted in the Swedish underground hard rock laboratory. Canister Retrieval Test (CRT) is a heating and infiltration test at a full-scale deposition hole. In this paper, we conducted thermo-hydro-mechanical coupled analysis for CRT and compared the results with measured data. The evolution of temperature and relative humidity and the profiles of bentonite's dry density were well reproduced by numerical analysis. Sensitivity analysis was also conducted in order to investigate the influence of hydraulic properties of surrounding rock mass on re-saturation behavior of bentonite in a deposition hole. (author)

  7. An accessible hydrogeological tool to monitor critical groundwater resources in hard-rock aquifers

    OpenAIRE

    Rohde, Melissa M.; Edmunds, W. Mike; Sharma, Somendra

    2015-01-01

    Groundwater resources are increasingly being relied on in rural areas for income generation and food security. However, there is currently a lack of simple, yet accessible hydrogeological tools to monitor critical groundwater resources, both for quantity and quality. This is particularly true in developing countries underlain by fractured hard rock aquifers, with low productivities. Electrical conductivity (EC) meters are presented here as an easy-to-use tool that can provide real-time data c...

  8. Groundwater resources in coastal hard rock terrains : Geostatistical and GIS approach

    OpenAIRE

    Dehkordi, S. Emad

    2009-01-01

    Stockholm archipelago is a combination of coastal and young glaciated conditions on hard rock geology with almost no primary porosity and very limited secondary porosity. Therefore the aquifer is both of limited capacity and exposed to salinity problem. In this context importance of fractures and soil cover is magnified. Lineaments are representatives of fractures in remote sensing. Fracture mapping in study area proves close correspondence between orientation of fractures and nearly located ...

  9. Release consequence analysis for a hypothetical geologic radioactive waste repository in hard rock

    International Nuclear Information System (INIS)

    This report makes an evaluation of the long-term behaviour of the wastes placed in a hard rock repository. Impacts were analyzed for the seven reference fuel cycles of WG 7. The reference repository for this study is for granitic rock or gneiss as the host rock. The descriptions of waste packages and repository facilities used in this study represent only one of many possible designs based on the multiple barriers concept. The repository's size is based on a nuclear economy producing 100 gigawatts of electricity per year for 1 year. The objective of the modeling efforts presented in this study is to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere and thus determine an estimate of the potential dose to humans so that the release consequence impacts of the various fuel cycles can be compared. Currently available hydrologic, leach, transport, and dose models were used in this study

  10. A study on the U speciation in groundwater of a hard rock aquifer in South India

    International Nuclear Information System (INIS)

    Speciation of uranium indicates the contribution of this ion into different species. An attempt has been made to study the spatial and temporal variations of U speciation in the hard rock aquifer of South India. The major rock types have granulite facies with high grade metamorphic rocks and younger intrusive. It also comprises of Fissile hornblende biotite gneiss, Charnockite, Quartzite, Granite and Flood Plain Alluvium. A total of 108 samples were collected from the handpumps of the study area for two seasons (Pre monsoon and South West monsoon). The groundwater samples were analysed for U and other ions like Ca2+, Mg2+, Na+ and K+, HCO3-, Cl-, SO42-, PO43-, NO3-, F-, H4SiO4, pH, EC and TDS using standard procedures

  11. Aespoe Pillar Stability Experiment. Final experiment design, monitoring results and observations

    International Nuclear Information System (INIS)

    The field part of the Aespoe Pillar Stability Experiment at the Aespoe Hard Rock Laboratory (HRL) was finished in 2004. The experiment was designed to induce and monitor the process of brittle failure, spalling, in a fractured rock mass under controlled conditions. The field part was successfully conducted and a large data set was obtained. This report presents the final design of the experiment, the results of the monitoring, and the observations made during the spalling process and when the spalled rock was removed. When heating of the rock was initiated the rock responded quickly. After only a few days the spalling process was activated in the notch, as indicated by the acoustic emission system, and shortly thereafter displacement readings were recorded. Contraction (radial expansion) of the rock was recorded by several instruments before the notch reached the instrument levels. This contraction is probably the result of a 3D re-distribution of the stresses. The temperature increase in the system was both slower and reached a steady state much earlier than predicted by the numerical models. The propagation of the notch was therefore halted after approximately one month of heating. The power to the electrical heaters was therefore doubled. Spalling then started up again, and in one month's time it had propagated to a depth of approximately five metres in the hole. A second steady state was now reached, but this time the heater power was kept constant for a while to let the rock settle before the confinement pressure was reduced from 700 kPa to 0 in decrements of 50 kPa. The rock mass response to the pressure drop was very limited until the pressure was lowered to approximately 200 kPa (the atmospheric pressure is not included in the given pressure values). Large displacements and a high acoustic emission hit frequency were then measured in the open hole. After the de-pressurization of the confined hole, the heaters were left on for approximately one week before

  12. A Coupled Thermo-Hydro-Mechanical Model of Jointed Hard Rock for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Xiaoying Zhuang

    2014-01-01

    Full Text Available Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.

  13. Long-range spatial dependence in fractured rock. Empirical evidence and implications for tracer transport

    International Nuclear Information System (INIS)

    Nonclassical stochastic continuum models incorporating long-range spatial dependence are evaluated as models for fractured crystalline rock. Open fractures and fracture zones are not modeled explicitly in this approach. The fracture zones and intact rock are modeled as a single stochastic continuum. The large contrasts between the fracture zones and unfractured rock are accounted for by making use of random field models specifically designed for highly variable systems. Hydraulic conductivity data derived from packer tests in the vicinity of the Aespoe Hard Rock Laboratory form the basis for the evaluation. The Aespoe log K data were found to be consistent with a fractal scaling model based on bounded fractional Levy motion (bfLm), a model that has been used previously to model highly variable sedimentary formations. However, the data are not sufficient to choose between this model, a fractional Brownian motion model for the normal-score transform of log K, and a conventional geostatistical model. Stochastic simulations conditioned by the Aespoe data coupled with flow and tracer transport calculations demonstrate that the models with long-range dependence predict earlier arrival times for contaminants. This demonstrates the need to evaluate this class of models when assessing the performance of proposed waste repositories. The relationship between intermediate-scale and large-scale transport properties in media with long-range dependence is also addressed. A new Monte Carlo method for stochastic upscaling of intermediate-scale field data is proposed

  14. Sustainable Ground Water Development in Hard Rock Aquifers in Low-Income Countries and the Role of UNESCO _ IUGS - IGCP projec -GROWNET-

    OpenAIRE

    S. D. Limaye

    2010-01-01

    Hard rock aquifers for the purpose of this Paper mean the non-carbonate, fractured rock aquifers in the terrain covered by crystalline basement complex, metamorphic rocks and also by extensive effusive volcanic rocks like the basalts of western India (Deccan traps. Ground water development in hard rock aquifer areas has always played a secondary role compared to that in the areas having high-yielding unconsolidated or semi-consolidated sediments and carbonate rocks. This has been due to the r...

  15. Evaluation of used methodology/methods in Aespoe HRL. Sections 0/700-1/475 and 1/475-2/265

    International Nuclear Information System (INIS)

    Some of the main objectives with the Aespoe Hard Rock Laboratory is reviewing and verifying the suitability of different investigations methods regarding bedrock characterization, test methods for detailed site investigations and to evaluate factors of importance for safety in realistic conditions. The SKB evaluation will result in a strategy planned to be used in the forthcoming site selection of a repository for high level radioactive waste. This report presents an evaluation of the methods used by SKB in the prediction of the bedrock prior to excavation. The prediction was based on the pre investigations carried out during 1986-1990. The review has followed the SKB classification of issue areas: geological/structural model, groundwater flow, groundwater chemistry, transport of solutes and mechanical stability. The review concerns SKB's objectives with the prediction and the different criteria for selection of variables - considering the demands of the performance assessment. This report includes evaluation of two tunnel sections, 0/700 - 1/475 and 1/475 - 2/265, comprising used data, prediction methods and prediction accuracy. By way of comparing predictions before excavation and outcome in the tunnel, a strict validation was performed. Based on the results from the validation, the applicability of different methods was estimated and the predictability of different subjects was assessed. It should be emphasised that the Aespoe predictions have not been directly intended for performance assessment purposes. However, it is of interest to see how the predictions relate to the information needs of performance assessment. By this it is possible to identify areas where more work needs to be done in the future, either in the operational phases at Aespoe or in other parts of the SKB program, thereby setting the predictions in an overall perspective from the point of view of performance assessment

  16. Assessment of fluoride contaminations in groundwater of hard rock aquifers in Madurai district, Tamil Nadu (India)

    Science.gov (United States)

    Thivya, C.; Chidambaram, S.; Rao, M. S.; Thilagavathi, R.; Prasanna, M. V.; Manikandan, S.

    2015-07-01

    The fluoride contamination in drinking water is already gone to the alarming level and it needs the immediate involvement and attention of all people to solve this problem. Fluoride problem is higher in hard rock terrains in worldwide and Madurai is such type of hard rock region. Totally 54 samples were collected from the Madurai district of Tamilnadu with respect to lithology. The samples collected were analysed for major cations and anions using standard procedures. The higher concentration of fluoride is noted in the Charnockite rock types of northern part of the study area. 20 % of samples are below 0.5 ppm and 6 % of samples are above 1.5 ppm exceeding the permissible limit. The affinity between the pH and fluoride ions in groundwater suggests that dissolution of fluoride bearing minerals in groundwater. The higher concentration of fluoride ions are observed in the lower EC concentration. The isotopic study suggests that fluoride is geogenic in nature. In factor scores, fluoride is noted in association with pH which indicates the dissolution process.

  17. An accessible hydrogeological tool to monitor critical groundwater resources in hard-rock aquifers

    Directory of Open Access Journals (Sweden)

    Melissa M Rohde

    2015-10-01

    Full Text Available Groundwater resources are increasingly being relied on in rural areas for income generation and food security. However, there is currently a lack of simple, yet accessible hydrogeological tools to monitor critical groundwater resources, both for quantity and quality. This is particularly true in developing countries underlain by fractured hard rock aquifers, with low productivities. Electrical conductivity (EC meters are presented here as an easy-to-use tool that can provide real-time data collection to enhance routine groundwater monitoring in rural areas. A program was established within a fractured hard rock watershed for over a year in Rajasthan, India to determine the effectiveness and controls over EC as a monitoring tool. The initial groundwater quality in this region was largely influenced by rainfall, modified by evapotranspiration with recognizable input from water-rock interaction in the later months following the monsoon season. Chloride concentrations were linearly correlated with EC in all of the sampled groundwater, but the strength of the correlation attenuated in the months following the monsoon. Recharge rates were estimated using the chloride mass balance (CMB approach, and then compared to the recharge rates derived from using EC as a surrogate for in what is referred to here as the CMB-EC approach. Recharge rates estimated from the CMB and CMB-EC methods were statistically similar (p=0.44.

  18. Aespoe Pillar Stability Experiment. Final 2D coupled thermo-mechanical modelling

    International Nuclear Information System (INIS)

    A site scale Pillar Stability Experiment is planned in the Aespoe Hard Rock Laboratory. One of the experiment's aims is to demonstrate the possibilities of predicting spalling in the fractured rock mass. In order to investigate the probability and conditions for spalling in the pillar 'prior to experiment' numerical simulations have been undertaken. This report presents the results obtained from 2D coupled thermo-mechanical numerical simulations that have been done with the Finite Element based programme JobFem. The 2D numerical simulations were conducted at two different depth levels, 0.5 and 1.5 m below tunnel floor. The in situ stresses have been confirmed with convergence measurements during the excavation of the tunnel. After updating the mechanical and thermal properties of the rock mass the final simulations have been undertaken. According to the modelling results the temperature in the pillar will increase from the initial 15.2 deg up to 58 deg after 120 days of heating. Based on these numerical simulations and on the thermal induced stresses the total stresses are expected to exceed 210 MPa at the border of the pillar for the level at 0.5 m below tunnel floor and might reach 180-182 MPa for the level at 1.5 m below tunnel floor. The stresses are slightly higher at the border of the confined hole. Upon these results and according to the rock mechanical properties the Crack Initiation Stress is exceeded at the border of the pillar already after the excavation phase. These results also illustrate that the Crack Damage Stress is exceeded only for the level at 0.5 m below tunnel floor and after at least 80 days of heating. The interpretation of the results shows that the required level of stress for spalling can be reached in the pillar

  19. Different spatial discretization methods of fault systems on heat transport processes in hard rock aquifers

    Science.gov (United States)

    Kruppa, Lisa; König, Christoph M.; Becker, Martin; Seidel, Torsten

    2016-04-01

    Most hard rock aquifers, which are important for geothermal use, contain fractures of different type and scale. These fault systems are of major significance for heat flow in the groundwater. The hydrogeological characterization of fault systems must therefore be part of any site investigation in hard rock aquifers and hydraulically important fault systems need to be appropriately represented in associated numerical models. This contribution discusses different spatial discretization methods of fault systems in three-dimensional groundwater models and their impact on the simulated groundwater flow field as well as density and viscosity dependent heat transport. The analysis includes a comparison of the convergence behavior and numerical stability of the different discretization methods. To ensure defendable results, the utilized numerical model SPRING was first verified against data from the Hydrocoin Level 1 Case 2 project. After verification, the software was used to evaluate the impact of different discretization strategies on steady-state and transient groundwater flow and transport model results. The results show a significant influence of the spatial discretization strategy on predicted flow rates and subsequent mass fluxes as well as energy balances.

  20. Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Task 6C

    International Nuclear Information System (INIS)

    This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization (SC) and performance assessment (PA) approaches to solute transport in fractured rock. The present report is concerned solely with Task 6C, which relates to the construction and parametrisation of a block-scale hydrostructural model of the TRUE Block Scale region of the Aespoe Hard Rock laboratory. The task objectives, specifications and outcome are summarised and reviewed. Also, consideration is given to how the hydrostructural model might affect the outcomes of Task 6D and 6E. The main conclusions of this review are summarised below: The Task 6C hydrostructural model is a more comprehensive approach to quantitatively describing a volume of fractured rock than has been achieved hitherto. The idea of including solute retention characteristics as indices attached to individual fractures is an efficient device resulting in a whole volume of fractured rock described by a few spreadsheets. The hydrostructural model is clearly defined and provides a useful test bed for Tasks 6D and 6E. It would have been beneficial if the specifications for Task 6C had been more clearly defined as a hierarchy of requirements, and performance measures had been defined and evaluated to allow comparison of alternative approaches. The device used to reduce connectivity, namely reducing the average size of background fractures, has the effect of producing a final model with an 'unnatural' gap in the overall distribution of fracture sizes. It appears that the exploratory boreholes could be important conductive structures within the region of the 200 m block even though they are segmented into shorter sections by packers. If correct, this implies that the boreholes should be included explicitly in the model if close replication of TRUE Block

  1. Thermal properties at Aespoe HRL. Analysis of distribution and scale factors

    International Nuclear Information System (INIS)

    A thermal model for the Aespoe HRL as well as a general strategy for thermal modelling is under development. As a part of that work, thermal conductivities have been modelled from reference values of thermal conductivity of different minerals and from the mineral composition of all Aespoe samples in the Sicada database. The produced thermal conductivity database has been analysed in terms of frequency, type of distribution, spatial distribution, variogram etc. A correction factor has been estimated to compensate for discrepancies between measured and calculated values. The calculated values have been corrected according to measured values. The data has been analysed according to different rock types. However, there are uncertainties in the base material of rock classification, mainly due to problem to distinguish between Aespoe diorite and Aevroe granite, but also because of different classification systems. There is a relationship between thermal conductivity and density for the rock types at Aespoe. Equations of the relationship have been developed based on all thermal conductivity, heat capacity and density measurements. The equations have been tested on two bore holes at Aespoe with promising results. It may be possible to evaluate the spatial distribution of the thermal properties from density loggings. However, more work is needed to develop a complete model including the handling of high and low density zones. There is an insufficient knowledge in the variation of thermal properties at different scales. If the whole variation within a rock type is in the cm-m scale the thermal influence on the canister is small. This is due to the fact that the small-scale variation in thermal properties is mainly averaged out in the 5-10 m scale. If the main variation within rock types is in the 5-10 m scale there is probably a significant effect on the canister temperature. However, it is likely that the observed variation occurs in both these scales. Simulation has been

  2. Fault Rock Zones Characterisation - Final report. TRUE-1 Continuation Project

    International Nuclear Information System (INIS)

    At the conclusion of the TRUE-1 and TRUE Block Scale experimental programmes at the Aespoe Hard Rock Laboratory one remaining identified uncertainty was the in situ internal structure of conductive structures, and in particular the in situ material properties of unconsolidated fault gouge of such conductive structures. With the aim of reducing these uncertainties an experimental program has been conducted at depth in the Aespoe Hard Rock Laboratory. Four conductive structures in the immediate vicinity of the Aespoe tunnel were identified for further study. Following basic geometrical and geological modelling based on tunnel observations, geological/ mineralogical and hydrogeological investigations in four boreholes at each site, epoxy resin was injected in selected packed off borehole sections containing the structure. Following a sufficient time for curing of the epoxy, the injected borehole 72 mm sections were overcored with a 300 mm core barrel. Customised techniques were employed to section the core in the borehole and for its retrieval out of the borehole. Following basic geological mapping, selected overcores were sectioned and were subject to image analysis to assess the pore structure using a variety of different descriptive geometrical attributes. In addition, an attempt was made to infer the porosity of the fault rock (including fault gouge) using binary images. Since analysis has been made on multiple slices of impregnated rock it is also possible to crudely map the 3D variability of a given entity. It was furthermore identified that porosity estimates, which range from some 10-70% are, apart from being dependent on the penetration of the epoxy, dependent on the resolution of the given image, the size of the averaging window, and the porosity components contained therein. The obtained quantifications of porosity can therefore only be regarded as ball-park relative porosities of a complete fault rock zones. It does not, however, provide firm

  3. Fault Rock Zones Characterisation - Final report. TRUE-1 Continuation Project

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, Anders (ed.) (Conterra AB (Sweden))

    2010-11-15

    At the conclusion of the TRUE-1 and TRUE Block Scale experimental programmes at the Aespoe Hard Rock Laboratory one remaining identified uncertainty was the in situ internal structure of conductive structures, and in particular the in situ material properties of unconsolidated fault gouge of such conductive structures. With the aim of reducing these uncertainties an experimental program has been conducted at depth in the Aespoe Hard Rock Laboratory. Four conductive structures in the immediate vicinity of the Aespoe tunnel were identified for further study. Following basic geometrical and geological modelling based on tunnel observations, geological/ mineralogical and hydrogeological investigations in four boreholes at each site, epoxy resin was injected in selected packed off borehole sections containing the structure. Following a sufficient time for curing of the epoxy, the injected borehole 72 mm sections were overcored with a 300 mm core barrel. Customised techniques were employed to section the core in the borehole and for its retrieval out of the borehole. Following basic geological mapping, selected overcores were sectioned and were subject to image analysis to assess the pore structure using a variety of different descriptive geometrical attributes. In addition, an attempt was made to infer the porosity of the fault rock (including fault gouge) using binary images. Since analysis has been made on multiple slices of impregnated rock it is also possible to crudely map the 3D variability of a given entity. It was furthermore identified that porosity estimates, which range from some 10-70% are, apart from being dependent on the penetration of the epoxy, dependent on the resolution of the given image, the size of the averaging window, and the porosity components contained therein. The obtained quantifications of porosity can therefore only be regarded as ball-park relative porosities of a complete fault rock zones. It does not, however, provide firm

  4. Hydrogeophysical characterization and data integration for the Sardon catchment hard rock aquifer (Spain)

    Science.gov (United States)

    Francés, Alain Pascal; Mohammed, Abubeker Ali; Roy, Jean; Mahmoudzadeh Ardekani, Mohammad Reza; Lambot, Sébastien; Lubczynski, Maciek

    2010-05-01

    Unaltered hard rocks are hydrogeologically characterized by low primary porosity and permeability. Productive aquifers can however be supported by fractured and/or weathered hard rocks. In this type of composite aquifers, the upper weathered layers have typically a storage function while the underlying fissured layers have a transmissive function. Such aquifer sequence is usually highly heterogeneous because the weathered and fractured zones are controlled by various factors such as mineralogy and texture of lithologies, regional and local tectonics, paleoclimate and interaction between these factors. In the proposed study we attempt to develop an efficient and accurate method to provide the hydrological characterization of a small hard rock (granite) aquifer within Sardon catchment (~80km2), located in the Iberian Meseta (west of Salamanca, Spain). The proposed method is based on the integration of five techniques : i) field mapping; ii) remote sensing imagery analysis (RS); iii) geographical information system (GIS); iv) hydrogeophysics; v) numerical flow modeling. The geological mapping including characterization of fractures was processed in GIS through the combination of conventional field survey and analysis of aerial photographs and space borne imagery. The hydrogeophysics complemented the previous work by: i) sub-surface characterization of weathered layers using vertical electrical soundings (VES) at 61 locations, an electromagnetic (EM) transect perpendicular to the main valley (~3 km length) and electrical resistivity tomography (ERT) at 13 locations; ii) ground penetrating radar (GPR) to derive the depth of the groundwater table to complement the information of the piezometric monitoring network (35 transects with a total length of ~23 km) in order to provide additional constrain of the numerical flow model; iii) magnetic resonance sounding (MRS) to derive the depth-wise subsurface water content and aquifer transmissivity at 15 locations. The collected

  5. Geological-economic evaluation model for pithead heap-leaching uranium deposits of hard-rock

    International Nuclear Information System (INIS)

    By analyzing the technical flow of pithead heap-leaching uranium deposits of hard-rock type, the authors analyze its 14 cost items such as ore mining fee and major materials fee etc., and set up a geological-economic evaluation model. Under this geological-evaluation model a computer evaluating program is made in Ziyuan and Lujing uranium ore-fields. The results of static evaluation show that or mining fee is the main part and amortization of both building and equipment and major materials fee are the secondary parts in the total cost of pithead heap-leaching mining. The computer program may assist decision-making in the way of helping decision-makers to select scientificaly the average grade of ore in pithead heap-leaching mining under a total cost. (authors)

  6. SITE-94. Rock mechanics modelling for the stability and safety of a nuclear waste repository. Executive summary

    International Nuclear Information System (INIS)

    This summary presents an outline of the aims and problems involved in a rock mechanics study which is published in, so far, three separate technical reports. The objectives of the study were to investigate the mechanical influence of repository excavation, swelling pressure, thermal loading and glaciation on the stability and safety of a hypothetical nuclear waste repository, in both far-and near-field scales. The Aespoe Hard Rock Laboratory test site was used as the target site for regional and local geology, in situ stress data and material properties. 17 refs

  7. Application of the multi-rate diffusion approach in tracer test studies at Aespoe HRL. Final report

    International Nuclear Information System (INIS)

    This report summarizes an investigation into heterogeneous diffusivity and associated parameters within granitic rocks at the Aespoe Hard Rock Laboratory (HRL). Our tasks for this investigation were: (1) to assess the potential for either anomalous or multi-rate diffusion within Aespoe rocks; (2) to evaluate existing data relating to anomalous and multi-rate diffusion within Aespoe rocks; (3) to perform scoping calculations in support of a Long Term Diffusion Experiment (LTDE) design; and (4) to begin developing a mathematical and computer model for solute advection in the presence of anomalous matrix diffusion. In addition to carrying out these tasks, we also report on (5) the late-time behavior of breakthrough curves. First, in regard to the potential for anomalous and multi-rate diffusion and analyses of existing data, we find that (1) in a literature review of 100 column experiments in various types of rock and sediment, rate coefficients decrease with experimental observation time. This is precisely what would be expected of both multi-rate and anomalous diffusion. (2) Three sets of through-diffusion experiments in Fenno-Scandian granitic rock found decreasing effective diffusivity, De, with sample length, while one set did not. (3) Based on diffusivity and sorption data, and speculation on matrix block size variability, the total variability of Da/a2 may reasonably be expected to exceed 4 orders of magnitude. (4) Analyses of two-well tracer data completed to date are ambiguous with respect to multi-rate diffusion. Analyses of TRUE data are currently underway and may support multi-rate diffusion. Second, in regard to the potential consequences of multi-rate and anomalous diffusion on nuclear waste disposal, we found the following key points: (1) No single value of diffusivity can represent the diffusion process at all time- or length-scales if diffusion is truly anomalous, while a single value of diffusivity will represent diffusion adequately for some cases

  8. U-Th series studies as an aid to hard-rock groundwater modelling

    International Nuclear Information System (INIS)

    Excavation of any underground space in hard-rock may change hydrological and hydrogeochemical conditions in its surroundings in a non-predictable way. It is known that fracture surface and adjacent rock may register information of changes in the chemistry of the groundwater circulating within fractures. This information may be obscured or lost as a result of excavation. Therefore, to predict possible modifications in fracture flow conditions and future evolution, it is necessary to know pre-excavation evolution and present situation. U-Th decay series contain radioactive elements which experience and register induced changes in groundwater conditions in different ways. Therefore, due to different chemistry and variety of half-lives, decay-series elements and their isotopes can be used to establish relevant time correlation for these changes, which is important in verifying pre-excavation groundwater flow models. Here we present two case studies where natural decay series are used to demonstrate the effects of man-made and natural hydrogeochemical disturbances. The sites of the cases are the Palmottu U deposit in SW Finland and the Pyhaesalmi Cu mine in western Finland. (orig.)

  9. Analysis of the Aespoe LPT2 pumping test via simulation and inverse modelling with HYDRASTAR

    International Nuclear Information System (INIS)

    A stochastic groundwater modelling study is presented for the Long-term Pumping Test (LPT2) conducted at the Aespoe Hard Rock Laboratory. It is a test case for HYDRASTAR, a stochastic continuum groundwater flow and transport model. Unlike previous modelling studies of LPT2, this study uses the inverse modelling capabilities of HYDRASTAR to condition the model results to the observed hydraulic heads. The purpose of this conditioning via inverse modelling is to improve the reliability of input hydraulic conductivity fields and thus minimise the uncertainty of the model predictions. Preliminary simulations evaluated the boundary conditions, grid extent and grid density, all of which were restricted by the computational demands of a larger domain and by code limitations. The preliminary simulations also indicated that the model is quite sensitive to changes in specific storativity and kriging parameters. The final calibrated model simulations were successful in representing the response of the rock mass to the LPT2. Specifically, the mean of the Monte Carlo realizations of simulated drawdowns generally reproduced the magnitude, timing, and shape of the observed drawdowns. The observed drawdowns generally were bracketed by an interval of plus or minus one standard deviation from the mean of the realizations. Some discrepancies in the magnitude and timing of the observed versus the simulated drawdowns were revealed at several locations, such as the upper sections of borehole KAS07. However, the ensemble of model realizations were centred on the observed drawdowns and bracketed the observed responses, supporting both the conceptual model and its representation by HYDRASTAR. 33 refs, figs

  10. Data Qualification and Data Summary Report: Intact Rock Properties Data on Tensile Strength, Schmidt Hammer Rebound Hardness, and Rock Triaxial Creep

    International Nuclear Information System (INIS)

    This report presents a systematic review of the available data in the TDMS that are relevant to the following intact rock properties: rock tensile strength, Schmidt hammer rebound hardness, and rock triaxial creep. Relevant data are compiled from qualified and unqualified sources into the summary DTNs and these DTNs are evaluated for qualification using the method of corroborating data as defined in AP-SIII.2Q, ''Qualification of Unqualified Data''. This report also presents a summary of the compiled information in the form of descriptive statistics and recommended values that will be contained in a Reference Information Base (RIB) item prepared in accordance with AP-SIII.4Q, ''Development, Review, Online Placement, and Maintenance of Individual Reference Information Base Data Items''. The primary purpose of this report is to produce qualified sets of data that include all relevant intact rock tensile strength, Schmidt hammer rebound hardness, and rock triaxial creep testing done over the course of the Yucca Mountain Project (YMP). A second purpose is to provide a qualified summary (i.e., a RIB data item) of the test results using descriptive statistics. The immediate purpose of the report is to support the data needs of repository design; however, the products are designed to be appropriate for general use by the YMP. The appropriateness and limitations, if any, of the data, with respect to the intended use, are addressed in this report

  11. Data Qualification and Data Summary Report: Intact Rock Properties Data on Tensile Strength, Schmidt Hammer Rebound Hardness, and Rock Triaxial Creep

    Energy Technology Data Exchange (ETDEWEB)

    E.M. Cikanek; R.J. Blakely; T.A. Grant; L.E. Safley

    2003-07-29

    This report presents a systematic review of the available data in the TDMS that are relevant to the following intact rock properties: rock tensile strength, Schmidt hammer rebound hardness, and rock triaxial creep. Relevant data are compiled from qualified and unqualified sources into the summary DTNs and these DTNs are evaluated for qualification using the method of corroborating data as defined in AP-SIII.2Q, ''Qualification of Unqualified Data''. This report also presents a summary of the compiled information in the form of descriptive statistics and recommended values that will be contained in a Reference Information Base (RIB) item prepared in accordance with AP-SIII.4Q, ''Development, Review, Online Placement, and Maintenance of Individual Reference Information Base Data Items''. The primary purpose of this report is to produce qualified sets of data that include all relevant intact rock tensile strength, Schmidt hammer rebound hardness, and rock triaxial creep testing done over the course of the Yucca Mountain Project (YMP). A second purpose is to provide a qualified summary (i.e., a RIB data item) of the test results using descriptive statistics. The immediate purpose of the report is to support the data needs of repository design; however, the products are designed to be appropriate for general use by the YMP. The appropriateness and limitations, if any, of the data, with respect to the intended use, are addressed in this report.

  12. Assessment of site-scale hydrogeological modelling possibilities in crystalline hard rock for safety appraisal

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J. [Cleanwater Hardrock Consulting, Corvallis, OR (United States); Luukkonen, A.

    2012-09-15

    This review describes the state-of-the-art in hydrogeological modelling for safety-case studies related to spent-fuel repositories in crystalline hard rock, focusing on issues of relevance for the KBS-3 disposal concept in Nordic environments. The review includes a survey of model capabilities and assumptions regarding groundwater flow processes, geological and excavation-related features, and boundary conditions for temperate, periglacial, and glacial climates. Modelling approaches are compared for research sites including the Stripa mine (Sweden), the Grimsel Test Site (Switzerland), the Whiteshell Underground Research Laboratory (Canada), the Aspo Hard Rock Laboratory and Simpevarp-Laxemar site (Sweden), the Forsmark site (Sweden), the Waste Isolation Pilot Plant site (USA), and Olkiluoto (Finland). Current hydrogeological models allow realistic representations, but are limited by availability of data to constrain their properties. Examples of calibrations of stochastic representations of heterogeneity are still scarce. Integrated models that couple flow and non-reactive transport are now well established, particularly those based on continuum representations. Models that include reactive transport are still mainly in the realm of research tools. Thus far, no single software tool allows fully coupled treatment of all relevant thermal, hydraulic, mechanical, and chemical transport processes in the bedrock, together with climate-related physical processes at the ground surface, and with explicit treatment of bedrock heterogeneity. Hence practical applications require combinations of models based on different simplifications. Key improvements can be expected in treatment of the unsaturated zone, simulation of heterogeneous infiltration at the surface, and hydromechanical coupling. Significant advances have already been made in the amounts and types of data that can be used in site-scale models, including large datasets to define topography and other surface

  13. Ellipticity of Rayleigh waves in basin and hard-rock sites in Northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-07-01

    We measure ellipticity of teleseismic Rayleigh waves at 95 seismic stations in Northern Italy, for wave period between 10 and 110 s, using an automatic technique and a large volume of high-quality seismic recordings from over 500 global earthquakes that occurred in 2008-2014. Northern Italy includes a wide range of crustal structures, from the wide and deep Po Plain sedimentary basin to outcropping sedimentary and crystalline rocks in the Northern Apennines and Alps. It thus provides an excellent case for studying the influence of shallow earth structure on polarization of surface waves. The ellipticity measurements show excellent spatial correlation with geological features in the region, such as high ellipticity associated with regions of low seismic velocity in the Po Plain and low ellipticity values in faster, hard rock regions in the Alps and Apennine mountains. Moreover, the observed ellipticity values also relate to the thickness of the basement, as highlighted by observed differences beneath the Alps and the Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region show substantial fit, particularly for T ˜ 38 s data. Discrepancy for shorter wave period suggests that slight modifications of the model are needed, and that the ellipticity measurements could help to better constrain the shallow crustal structure of the region. Predictions for the Po Plain are larger than the observations by a factor of four or more and transition from retrograde to prograde Rayleigh wave motion at the surface for periods of T ˜ 10-13 s is predicted for seismic stations in the plain. Analysis of corresponding real data indicates a possible detection of teleseismic prograde particle motion, but the weak teleseismic earthquake signals are mixed with ambient noise signals at the predicted, short, transition periods. Detection of the period of polarity inversion from the joint analysis of earthquake and ambient noise

  14. Ellipticity of Rayleigh waves in basin and hard-rock sites in Northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-04-01

    We measure ellipticity of teleseismic Rayleigh waves at 95 seismic stations in Northern Italy, for wave period between 10 s and 110 s, using an automatic technique and a large volume of high-quality seismic recordings from over 500 global earthquakes that occurred in 2008-2014. Northern Italy includes a wide range of crustal structures, from the wide and deep Po Plain sedimentary basin to outcropping sedimentary and cristalline rocks in the Northern Apennines and Alps. It thus provides an excellent case for studying the influence of shallow earth structure on polarisation of surface waves. The ellipticity measurements show excellent spatial correlation with geological features in the region, such as high ellipticity associated with regions of low seismic velocity in the Po Plain and low ellipticity values in faster, hard rock regions in the Alps and Apennine mountains. Moreover, the observed ellipticity values also relate to the thickness of the basement, as highlighted by observed differences beneath the Alps and the Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region show substantial fit, particularly for T ˜ 38 s data. Discrepancy for shorter wave period suggests that slight modifications of the model are needed, and that the ellipticity measurements could help to better constrain the shallow crustal structure of the region. Predictions for the Po Plain are larger than the observations by a factor of four or more and transition from retrograde to prograde Rayleigh wave motion at the surface for periods of T ˜ 10-13 s is predicted for seismic stations in the Plain. Analysis of corresponding real data indicates a possible detection of teleseismic prograde particle motion, but the weak teleseismic earthquake signals are mixed with ambient noise signals at the predicted, short, transition periods. Detection of the period of polarity inversion from the joint analysis of earthquake and ambient noise

  15. A new diamond bit for extra-hard, compact and nonabrasive rock formation

    Institute of Scientific and Technical Information of China (English)

    王佳亮; 张绍和

    2015-01-01

    A new impregnated diamond bit was designed to solve the slipping problem when impregnated diamond bit was used for extra-hard, compact, and nonabrasive rock formation. Adding SiC grits into matrix, SiC grits can easily be exfoliated from the surface of the matrix due to weak holding-force with matrix, which made the surface non-smooth. ThreeФ36/24 mm laboratorial bits were manufactured to conduct a laboratory drilling test on zirconiacorundum refractory brick. The laboratory drilling test indicates that the abrasive resistance of the bit work layer is proportional to the SiC concentation. The higher the concentration, the weaker the abrasive resistance of matrix. The new impregnated diamond bit was applied to a mining area drilling construction in Jiangxi province, China. Field drilling application indicates that the ROP (rate of penetration) of the new bit is approximately two to three times that of the common bits. Compared with the common bits, the surface of the new bit has typical abrasive wear characteristics, and the metabolic rate of the diamond can be well matched to the wear rate of the matrix.

  16. A self propelled drilling system for hard-rock, horizontal and coiled tube drilling

    Energy Technology Data Exchange (ETDEWEB)

    Biglin, D.; Wassell, M.

    1997-12-31

    Several advancements are needed to improve the efficiency and reliability of both hard rock drilling and extended reach drilling. This paper will present a Self Propelled Drilling System (SPDS) which can grip the borehole wall in order to provide a stable platform for the application of weight on bit (WOB) and resisting the reactive torque created by the downhole drilling motor, bit and formation interaction. The system will also dampen the damaging effects of drill string vibration. This tool employs two hydraulically activated anchors (front and rear) to grip the borehole wall, and a two-way thrust mandrel to apply both the drilling force to the bit, and a retraction force to pull the drill string into the hole. Forward drilling motion will commence by sequencing the anchor pistons and thrust mandrel to allow the tool to walk in a stepping motion. The SPDS has a microprocessor to control valve timing, sensing and communication functions. An optional Measurement While Drilling (MWD) interface can provide two-way communication of critical operating parameters such as hydraulic pressure and piston location. This information can then be telemetered to the surface, or used downhole to autonomously control system parameters such as anchor and thrust force or damping characteristics.

  17. Selected elements of rock burst state assessment in case studies from the Silesian hard coal mines

    Institute of Scientific and Technical Information of China (English)

    KABIESZ Józef; MAKóWKA Janusz

    2009-01-01

    Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulting from the existing in this area surface infrastructure. One of the most important problems of Polish mining is the rock burst hazard and reliable evaluation of its condition. During long-years' mining practice in Poland a comprehensive system of evaluation and control of this hazard was de-veloped. In the paper the main aspects of rock burst hazard state evaluation will be presented, comprising: 1) rock mass inclination for rock bursts, I.e., rock strength properties investigation, comprehensive parametric evaluation of rock mass inclination for rock bursts, prognosis of seismic events induced by mining operations, methods of computer-aided modelling of stress and rock mass deformation parameters distribution, strategic rock mass classification under rock burst degrees; 2) immediate seismic and rock burst hazard state evaluation, I.e., low diameter test drilling method, seismologic and seismoacoustic method, comprehensive method of rock burst hazard state evaluation, non-standard methods of evaluation; 3) legal aspects of rock burst hazard state evaluation. Selected elements of the hazard state evaluation system are illustrated with specific practical examples of their applica-tion.

  18. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  19. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    International Nuclear Information System (INIS)

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set shows an intense

  20. Effect of cation exchange of major cation chemistry in the large scale redox experiment at Aespoe. Revision 1

    International Nuclear Information System (INIS)

    Geochemical modeling was used to test the hypothesis that cation exchange with fracture-lining clays during fluid mixing in the Aespoe Hard Rock Laboratory can significantly affect major element chemistry. Conservative mixing models do not adequately account for changes in Na, Ca and Mg concentrations during mixing. Mixing between relatively dilute shallow waters and more concentrated waters at depth along fracture zones was modeled using the EQ3/6 geochemical modeling package. A cation exchange model was added to the code to describe simultaneously aqueous speciation, mineral precipitation/dissolution, and equilibration between a fluid and a cation exchanger. Fluid chemistries predicted to result from mixing were compared with those monitored from boreholes intersecting the fracture zone. Modeling results suggest that less than 0.1 equivalent of a smectite exchanger per liter of groundwater is necessary to account for discrepancies between predictions from a conservative mixing model and measured Na and Ca concentrations. This quantity of exchanger equates to an effective fracture coating thickness of 20 microm or less given a fracture aperture width of 1,000 microm or less. Trends in cation ratios in the fluid cannot be used to predict trends in cation ratios on the exchanger because of the influence of ionic strength on heterovalent exchange equilibrium. It is expected that Na for Ca exchange will dominate when shallow waters such as HBHO2 are mixed with deeper waters. In contrast, Na for Mg exchange will dominate mixing between deeper waters

  1. A study on variation in dissolved silica concentration in groundwater of hard rock aquifers in Southeast coast of India

    Science.gov (United States)

    Pradeep, K.; Nepolian, M.; Anandhan, P.; Chandran; Kaviyarasan, R.; Prasanna, M. V.; Chidambaram, S.

    2016-03-01

    Ground water of hard rock aquifers due to its lesser permeability results in the increased residence time, which leads to the higher concentration of ions. Hence in order to understand the hydro-geochemistry of the groundwater of a hard rock aquifer in India, 23 groundwater samples were collected from different locations of the study area and subjected to analysis of major cations and anions. The results of silica showed different range of concentration and was plotted in different groups. In order to understand the reason for this variation, different techniques like Thermodynamics, Statistics and GIS were adopted and it was inferred that the concentration was mainly governed by lithology and land use pattern of the study area.

  2. Hard Rock Miners` Phthisis in 19th and Early 20th Century Britain: From Diagnosis to Compensation

    OpenAIRE

    Mintz, Fredric

    2009-01-01

    AbstractIntroduction: Hard Rock Miners Phthisis in 19th and Early 20th Century Britain: From Diagnosis to CompensationByFredric MintzDoctor of Philosophy in HistoryProfessor Thomas Laqueur, ChairThe development of new technologies and new patterns of working were indispensable to the accelerated economic growth, which characterized most of nineteenth century Britain. For much of that period the demand for raw siliceous containing materials increased sharply. In this process, equipment, which ...

  3. Joint ANDRA/Nirex/SKB zone of excavation disturbance experiment (ZEDEX) at the Aspo hard rock laboratory

    International Nuclear Information System (INIS)

    The excavation of access shafts and tunnels and of the disposal areas of a waste repository will cause a disturbance in the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. For a number of disposal concepts this disturbance may be important for the operational and/or post-closure safety of the repository. Furthermore the disturbance may extend over time as a consequence of processes such as stress relaxation. The sponsors of ZEDEX, namely ANDRA, Nirex and SKB, are interested in developing the ability to produce reliable models of the disturbed zone that will develop around large cross-section excavations in fractured hard rock masses that are initially water saturated. Various models have been developed to calculate the important characteristics of the disturbed zone in such rock masses as a function of parameters related to the rock mass quality and the geometric description of the excavation. ZEDEX was initiated in the Aspo Hard Rock Laboratory in April 1994 with drilling and instrumentation of boreholes running alongside the planned extension of the spiral access ramp and a planned parallel experimental tunnel. ZEDEX has been designed to generate information for alternative methods of excavation. The extension to the spiral ramp is to be made by tunnel boring whereas the parallel experimental tunnel will be excavated in part by ''normal'' basting and in part by smooth blasting. The objective is to build confidence in the modelling of the disturbed zone to support the selection of excavation methods for repository construction. (authors). 3 figs

  4. Hydrogeophysics and remote sensing for the design of hydrogeological conceptual models in hard rocks - Sardón catchment (Spain)

    Science.gov (United States)

    Francés, Alain P.; Lubczynski, Maciek W.; Roy, Jean; Santos, Fernando A. M.; Mahmoudzadeh Ardekani, Mohammad R.

    2014-11-01

    Hard rock aquifers are highly heterogeneous and hydrogeologically complex. To contribute to the design of hydrogeological conceptual models of hard rock aquifers, we propose a multi-techniques methodology based on a downward approach that combines remote sensing (RS), non-invasive hydrogeophysics and hydrogeological field data acquisition. The proposed methodology is particularly suitable for data scarce areas. It was applied in the pilot research area of Sardón catchment (80 km2) located west of Salamanca (Spain). The area was selected because of hard-rock hydrogeology, semi-arid climate and scarcity of groundwater resources. The proposed methodology consisted of three main steps. First, we detected the main hydrogeological features at the catchment scale by processing: (i) a high resolution digital terrain model to map lineaments and to outline fault zones; and (ii) high-resolution, multispectral satellite QuickBird and WorldView-2 images to map the outcropping granite. Second, we characterized at the local scale the hydrogeological features identified at step one with: i) ground penetrating radar (GPR) to assess groundwater table depth complementing the available monitoring network data; ii) 2D electric resistivity tomography (ERT) and frequency domain electromagnetic (FDEM) to retrieve the hydrostratigraphy along selected survey transects; iii) magnetic resonance soundings (MRS) to retrieve the hydrostratigraphy and aquifer parameters at the selected survey sites. In the third step, we drilled 5 boreholes (25 to 48 m deep) and performed slug tests to verify the hydrogeophysical interpretation and to calibrate the MRS parameters. Finally, we compiled and integrated all acquired data to define the geometry and parameters of the Sardón aquifer at the catchment scale. In line with a general conceptual model of hard rock aquifers, we identified two main hydrostratigraphic layers: a saprolite layer and a fissured layer. Both layers were intersected and drained by

  5. Analysis of groundwater-level response to rainfall and estimation of annual recharge in fractured hard rock aquifers, NW Ireland

    Science.gov (United States)

    Cai, Zuansi; Ofterdinger, Ulrich

    2016-04-01

    Despite fractured hard rock aquifers underlying over 65% of Ireland, knowledge of key processes controlling groundwater recharge in these bedrock systems is inadequately constrained. In this study, we examined 19 groundwater-level hydrographs from two Irish hillslope sites underlain by hard rock aquifers. Water-level time-series in clustered monitoring wells completed at the subsoil, soil/bedrock interface, shallow and deep bedrocks were continuously monitored hourly over two hydrological years. Correlation methods were applied to investigate groundwater-level response to rainfall, as well as its seasonal variations. The results reveal that the direct groundwater recharge to the shallow and deep bedrocks on hillslope is very limited. Water-level variations within these geological units are likely dominated by slow flow rock matrix storage. The rapid responses to rainfall (⩽2 h) with little seasonal variations were observed to the monitoring wells installed at the subsoil and soil/bedrock interface, as well as those in the shallow or deep bedrocks at the base of the hillslope. This suggests that the direct recharge takes place within these units. An automated time-series procedure using the water-table fluctuation method was developed to estimate groundwater recharge from the water-level and rainfall data. Results show the annual recharge rates of 42-197 mm/yr in the subsoil and soil/bedrock interface, which represent 4-19% of the annual rainfall. Statistical analysis of the relationship between the rainfall intensity and water-table rise reveal that the low rainfall intensity group (⩽1 mm/h) has greater impact on the groundwater recharge rate than other groups (>1 mm/h). This study shows that the combination of the time-series analysis and the water-table fluctuation method could be an useful approach to investigate groundwater recharge in fractured hard rock aquifers in Ireland.

  6. A comparison of the effects of hard rock and easy listening on the frequency of observed inappropriate behaviors: control of environmental antecedents in a large public area.

    Science.gov (United States)

    Harris, C S; Bradley, R J; Titus, S K

    1992-01-01

    Observation of clients at a state mental health hospital by direct care staff indicated that they appeared to act in more inappropriate ways when "hard rock" or "rap" music was played in an open courtyard than when "easy listening" or "country" music was played. A study was conducted to compare the inappropriate behavior of clients when hard rock and rap music were played (21 days), followed by easy listening and country and western music (21 days). This comparison was followed by a reversal phase in which hard rock and rap music were again played (18 days). The behaviors of the clients were observed and recorded via a controlled methodology. The results demonstrated that more inappropriate behavior was observed under conditions in which hard rock and rap music were played than when easy listening and country western music were played. The implications of these findings are discussed. PMID:10118493

  7. Influence of confining stress on fracture characteristics and cutting efficiency of TBM cutters conducted on soft and hard rock

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-shuo; CAO Ping; LIU Jie; JIANG Zhe

    2015-01-01

    Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine (TRW-3000) designed and manufactured in Central South University (China). Results are obtained by performing analysis on the fracture scopes of cement and granite plates, the characteristics of cutting force in cutting processes and the cutting efficiency. Firstly, the increase of latitude fracture scope and the decrease of longitude fracture scope are both more notable in the tests conducted on cement plates subjected to the increasing confining stresses; secondly, the increase tendency of peak penetration forces obtained from tests conducted on granite plates is more obvious, however, the increase tendencies of average penetration forces achieved from cement and granite plates are close to each other; thirdly, the cutting efficiency could be improved by increasing the spacing between cutters when the confining stress which acts on soft and hard rock increases in a certain degree, and the cutting efficiency of soft rock is more sensitive to the varying confining stresses.

  8. Couple analyzing the acoustic emission characters from hard composite rock fracture

    Institute of Scientific and Technical Information of China (English)

    Xingping Lai; Linhai Wang; Meifeng Cai

    2004-01-01

    Rock mass is fractured media. Its fracture is a nonlinear process. The accumulation of acoustic emission (AE) is closely related to the degree of damage. The dynamics problem is simply described based on the non-equilibrium statistical theory of crack evolvement, trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), the characters of AE sig nals from rock damage in a mined-out area is synthetically analyzed and evaluated. These provide an evidence to reverse deduce and accurately infer the position of rock fracture for dynamical hazard control.

  9. SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Alan Black; Arnis Judzis

    2004-10-01

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rock cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology

  10. SMALLER FOOTPRINT DRILLING SYSTEM FOR DEEP AND HARD ROCK ENVIRONMENTS; FEASIBILITY OF ULTRA-HIGH SPEED DIAMOND DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Alan Black; Arnis Judzis

    2004-10-01

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high (greater than 10,000 rpm) rotational speeds. The work includes a feasibility of concept research effort aimed at development and test results that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with rigs having a smaller footprint to be more mobile. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration rock cutting with substantially lower inputs of energy and loads. The project draws on TerraTek results submitted to NASA's ''Drilling on Mars'' program. The objective of that program was to demonstrate miniaturization of a robust and mobile drilling system that expends small amounts of energy. TerraTek successfully tested ultrahigh speed ({approx}40,000 rpm) small kerf diamond coring. Adaptation to the oilfield will require innovative bit designs for full hole drilling or continuous coring and the eventual development of downhole ultra-high speed drives. For domestic operations involving hard rock and deep oil and gas plays, improvements in penetration rates is an opportunity to reduce well costs and make viable certain field developments. An estimate of North American hard rock drilling costs is in excess of $1,200 MM. Thus potential savings of $200 MM to $600 MM are possible if drilling rates are doubled [assuming bit life is reasonable]. The net result for operators is improved profit margin as well as an improved position on reserves. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology

  11. Aespoe Pillar Stability Experiment. Modelling of fracture development of APSE by FRACOD

    International Nuclear Information System (INIS)

    An in-situ experiment has started at Aespoe HRL to investigate the stability of a pillar between two closely located boreholes of deposition hole scale. This full-scale experiment is named the Aespoe Pillar Stability Experiment (APSE). One of the holes will be pressurized with 0.8 MPa water pressure to simulate confinement by backfill. Thermal stresses will be applied in the pillar by the use of electric heaters to reach the spalling conditions. To quantify the degree of damage during the experiment, an Acoustic Emission (AE) system will be used and strain measurements will be installed. FRACOD is a two dimensional BEM/DDM code for fracturing analysis in rock material. Here it has been used to model the rock mass response during the planned sequences of excavation-confinement-heating. The models predict the stress and displacement fields, fracture initiation and propagation, coalescence and the final failure of the rock mass. The presences of pre-existing fractures, which may have significant influence on the pillar behaviour, have also been considered in the modelling. This report summarises the modelling work using FRACOD to simulate the various experimental stages

  12. Finite element calculation and model test for studying rock pressure manifestation in face during water infusion of hard roof

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Y.; Chen, H. (Beijing Research Institute of Coal Mining (China))

    1990-03-01

    Using finite element method and experimental models, the author studies the characteristics of rock pressure manifestation in working face before and after water infusion of hard roof, and under different water-infusion conditions. Comparative analysis shows that water infusion plasticizes the roof rockmass and changes the stress distribution, deformation and displacement of roof, so that the peaks of tensile and compression stresses are transferred to the hanging roof over the goaf. This facilitates the fracture and caving of roof in succession and reduces the dynamic load on the support, force transmission coefficient, and the intensity of periodic weighting. Theoretically, high pressure water infusion is an effective technical approach for controlling hard roof. 19 figs., 8 tabs.

  13. Occurrence of the radionuclides in groundwater of crystalline hard rocks regions of central part Tamil Nadu, India

    International Nuclear Information System (INIS)

    Samples were collected in hard rock region central parts of Tamilnadu, South India to assess the U and 222Rn levels in groundwater belonging to various lithologies and evaluate their correlations with other water quality parameters. The order of dominance of U in groundwater is; Granite> Charnockite> Fissile Hornblende biotite gneiss> Flood Plain Alluvium> Quartzite, while that of 222Rn is: Granite> Quartzite> Charnockite > Fissile Hornblende biotite gneiss> Flood Plain Alluvium. Both U and 222Rn concentrations were compared with drinking water standards and a few samples show levels above the permissible limits. High degree of weathering of granitic rocks and long contact time of groundwater with the aquifer matrix could be the reason for enhanced U and 222Rn levels in groundwater. (author)

  14. Radon, fluoride and 62 elements as determined by ICP-MS in 145 Norwegian hard rock groundwater samples

    International Nuclear Information System (INIS)

    Hard rock groundwater (145) samples collected from private drinking water wells in the environment of Oslo and Bergen were analysed for their radon and fluoride contents. Also 62 elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). For 59 elements, more than 50% of all concentration values were above the detection limit. Characteristic differences between the Oslo- and Bergen-dataset can be shown to be related to host rock lithology. Variation in element contents generally spans 2-6 orders of magnitude. Concentrations of several elements (e.g. Ba, F, Fe, Mn, Na, Rn) exceed current drinking water action levels in a significant number of cases. High levels of other parameters such as Be, Mo, Th and U, which could have an impact on health, were observed. There are no Norwegian action levels currently defined for these elements. The economic and toxicological impacts of these findings require urgent assessment

  15. The fate of nitrogen and sulfur in hard-rock aquifers as shown by sulfate-isotope tracing

    OpenAIRE

    Pauwels, H.; Ayraud Vergnaud, V.; Aquilina, L; Molenat, Jérôme

    2010-01-01

    Stable SO4 isotopes (delta S-34(-SO4) and delta O-18(-SO4)). and more occasionally delta N-15(-NO3) were studied in groundwater from seven hard-rock aquifer catchments. The sites are located in Brittany (France) and all are characterized by intensive agricultural activity. The purpose of the study was to investigate the potential use of these isotopes for highlighting the fate of both SO4 and NO3 in the different aquifer compartments. Nitrate-contaminated groundwater occurs in the regolith; d...

  16. Comparison of Acoustic Energy Meter (AEM) and Schmidt hammer 'R' for rapid assessment of rock surface hardness: a preliminary assessment from southeast Queensland, Australia

    Science.gov (United States)

    Brook, Martin; Winkler, Stefan

    2015-04-01

    This research focuses on one of the key challenges in geomorphology - quantifying rock surface hardness via in situ measurements, to provide information on rock physical properties. This has been a focus in recent years with the rapid emergence of studies that center on surface and near surface weathering impacts, and rates of material loss. Indeed, a key element to understanding how weathering and erosion processes combine to influence rock surface (and landscape) evolution is the measurement and monitoring of rock surface hardness. We provide results from a preliminary assessment of the applicability of the Acoustic Energy Meter (AEM) to subaerial rock surface hardness, in comparison with an N-Type Schmidt hammer. The AEM apparatus consists of a geophone which is in contact with the rock surface and some electronics. The AEM is held normal to the surface to be tested and the surface is struck with a small hammer (typically 0.75 kg), with the AEM quantifying the decay time of seismically-induced oscillations within the top c. 1-2 m of the rock mass. Previous work using an AEM has focused on measuring roof stability and delamination in South African underground coal, gold and platinum mines, where long AEM reverberation times correlated well with weak rock mass and dense microfracturing. However, the technique has rarely been applied to the assessment of rock surfaces in a subaerial setting. We applied the technique to a range of lithologies at five sites in southeast Queensland in the Brisbane area, each an exposure of phyllite, granite, mudstone, argillite or volcanic tuff. The aims were: (1) quantifying the response of different rock masses to the AEM technique; and (2) assessing the applicability of the AEM as a rapid in situ measure of rock hardness by comparing results with Schmidt hammer 'R' values from the same exposures. Results showed that the AEM is useful in discriminating rock hardness across rocks with different lithological properties. Second, an

  17. Efficiency increase of hard rock destruction with the use of eccentric pulses

    Science.gov (United States)

    Pushmin, P.; Romanov, G.

    2015-11-01

    The increase of efficiency of expendable well-drilling directly depends on the mechanism of rock destruction. The depth of hole coverage should be at the maximum possible value and equal along the whole contact area. The design features of performing rock- destruction tool in rotary drilling prevent the cutters, located on different distance from rotation axis, from working with equal intensity. The application of the shock pulses to a boring tool increases the mechanical drilling speed and sinking per revolution. One of the techniques for the efficiency increase is the application of impactor machines. On the other hand, the high values of mechanical drilling speed require the high values of impact energy which results in high power inputs energy consumption. The use of eccentric impact loading instead of central one can provide the enhancement of rock destruction efficiency, lower the power inputs, and decrease the risk of borehole deviation.

  18. CSM/OCRD hard rock test facility at the CSM experimental mine, Idaho Springs, Colorado

    International Nuclear Information System (INIS)

    This report is the first in a series describing research conducted by the Colorado School of Mines (CSM) for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. A special room, called the CSM/OCRD room, was excavated for the purpose of assessing blast damage in the rock around the room. Even though this mine is not proposed as a nuclear waste repository site, the instrumentation and methods of blast damage assessment developed in this project are applicable to proposed repository sites. This report describes the room, and summarizes the overall experimental program. 4 references, 2 figures

  19. Hydrogeological and geophysical study for deeper groundwater resource in quartzitic hard rock ridge region from 2D resistivity data

    Indian Academy of Sciences (India)

    Dewashish Kumar; V Ananda Rao; V S Sarma

    2014-04-01

    Electrical resistivity method is a versatile and economical technique for groundwater prospecting in different geological settings due to wide spectrum of resistivity compared to other geophysical parameters. Exploration and exploitation of groundwater, a vital and precious resource, is a challenging task in hard rock, which exhibits inherent heterogeneity. In the present study, two-dimensional Electrical Resistivity Tomography (2D-ERT) technique using two different arrays, viz., pole–dipole and pole–pole, were deployed to look into high signal strength data in a tectonically disturbed hard rock ridge region for groundwater. Four selected sites were investigated. 2D subsurface resistivity tomography data were collected using Syscal Pro Switch-10 channel system and covered a 2 km long profile in a tough terrain. The hydrogeological interpretation based on resistivity models reveal the water horizons trap within the clayey sand and weathered/fractured quartzite formations. Aquifer resistivity lies between ∼3–35 and 100–200 m. The results of the resistivity models decipher potential aquifer lying between 40 and 88 m depth, nevertheless, it corroborates with the static water level measurements in the area of study. The advantage of using pole–pole in conjunction with the pole–dipole array is well appreciated and proved worth which gives clear insight of the aquifer extent, variability and their dimension from shallow to deeper strata from the hydrogeological perspective in the present geological context.

  20. Significance of Geological Parameters for Predicting Water Inflow in Hard Rock Tunnels

    Science.gov (United States)

    Holmøy, K. H.; Nilsen, B.

    2014-05-01

    One of the most challenging aspects of tunnelling is prognostication of water inflows. More reliable prediction of groundwater inflow may give considerable economical saving for future tunnel projects and may also prevent damage of environment and installations on the surface. This paper is discussing the significance of eight hypotheses regarding geological parameters for predicting water inflow in tunnels. The respective hypotheses have been tested as part of a recent research project in Norway. Six Norwegian tunnels with different geological conditions were selected for the research; the Romeriksporten, Frøya, T-baneringen, Lunner, Skaugum, and Storsand tunnels. Based on detailed study of these tunnels, the hypotheses are tested by comparing water inflow with geological parameters and factors such as Q value, faulting, rock stress orientation, rock cover, thickness of permeable soil or depth of lake/sea above the tunnel, rock type, and width of weakness zones. It is found that four out of the eight tested hypotheses are supported, two have low to medium support and two are not supported. One unexpected result is that for the tunnels covered by this study, the water inflow was found to increase with rock cover.

  1. Utilization of hard rock dust with red clay to produce roof tiles

    Directory of Open Access Journals (Sweden)

    Mst. Shanjida Sultana

    2015-03-01

    Full Text Available Utilization of rock dust to produce roof tiles and its effects on properties of tiles, mixed with red clay collected from Naogaon district of Bangladesh were investigated. After proper characterization of the raw materials, tiles were prepared with different percentages of rock dust (10-50% mixed with clay sintered from 850-1100 °C temperature. Rock dust has been found good for using as fluxing material after XRF study. The samples were tested for different properties such as water absorption, porosity, mechanical strength, linear shrinkage, and bulk density. The strength values have exceeded the minimum standard requirement for roof tiles with low water absorption in most samples. The results obtained made it possible to conclude about the possibility of producing roof tiles incorporating up to 40% of rock dust having better properties (lower water absorption 6.5%, strength value 31.97 MPa fired at 900 °C. Therefore these dust acts as a fluxing agent and reducing the sinteringtemperature of the clay material.

  2. Test with different stress measurement methods in two orthogonal bore holes in Aespoe HRL

    International Nuclear Information System (INIS)

    Within the scope of work, to provide the necessary rock mechanics support for the site investigations, SKB has studied some available pieces of equipment for in situ stress measurements in deep boreholes. A project with the objective to compare three different pieces of equipment for in situ stress measurements under similar conditions has been carried out. The main objective for the project is to compare the three different pieces of equipment for in situ stress measurements and find a strategy for SKB's Site Investigations to determine the state of stress in the rock mass. Two units of equipment use the overcoring method while the third uses the hydraulic fracturing method. The overcoring was performed by AECL, using Deep Door stopper Gauge System (DDGS), and SwedPower, using their triaxial strain measuring instrument (Borre Probe). MeSy Geo Systeme GmbH performed the hydraulic fracturing. The DDGS system is a new method to SKB while the experience of the SwedPower overcoring and the hydraulic fracturing methods are long. The tests were performed in the same orthogonal boreholes at Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The measured results have been verified against known conditions at the Aespoe HRL. The results from the three in situ stress measurement methods rose more questions than answers. Which illustrate the complexity to determine the in situ stresses in a rock mass. To understand the difference in results and answer the questions, it was necessary to do deeper investigations such as laboratory tests and theoretical calculations such as geological structure model, analysis of the influence of a nearby fracture, P-wave measurements, uniaxial tests on small cores from the HQ-3 core, theoretical and numerical analyses of the hole bottom (theoretical strains, stress concentrations and microcracking), auditing of DDGS measurements results and assumptions in the DDGS analyse and microscopy investigations on the cores. The following conclusions

  3. Discrete-feature modelling of the Aespoe Site: 1. Discrete-fracture network models for the repository scale

    International Nuclear Information System (INIS)

    This report describes the statistical derivation and partial validation of discrete-fracture network (DFN) models for the rock beneath the island of Aespoe in southeastern Sweden. The purpose was to develop DFN representations of the rock mass within a hypothetical, spent-fuel repository, located under Aespoe. Analyses are presented for four major lithologic types, with separate analyses of the rock within fracture zones, the rock excluding fracture zones, and all rock. Complete DFN models are proposed as descriptions of the rock mass in the near field. The procedure for validation, by comparison between actual and simulated packer tests, was found to be useful for discriminating among candidate DFN models. In particular, the validation approach was shown to be sensitive to a change in the fracture location (clustering) model, and to a change in the variance of single-fracture transmissivity. The proposed models are defined in terms of stochastic processes and statistical distributions, and thus are descriptive of the variability of the fracture system. This report includes discussion of the numerous sources of uncertainty in the models, including uncertainty that results from the variability of the natural system. 62 refs

  4. Hard rock excavation at the CSM/OCRD test site using Swedish blast design techniques

    International Nuclear Information System (INIS)

    This report is the third in a series describing research conducted by the Colorado School of Mines for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. A special room, called the CSM/OCRD room, was excavated at the CSM experimental mine for the purpose of assessing blast damage in the rock around the room. Even though this mine is not proposed as a nuclear waste repository site, the instrumentation and methods of blast damage assessment developed in this project are applicable to proposed repository sites. This report describes the application of Swedish blasting technology for the excavation of the test room. The design of the blasting patterns including the selection of explosives, hole sizes and location, explosive loading densities, and delay intervals is based upon the theories of Langefors and Kihlstrom in combination with methods used at the Swedish Detonic Research Foundation for minimizing unwanted rock damage. The practical application of the design procedures to seven rounds and the achieved results is discussed

  5. Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

    Energy Technology Data Exchange (ETDEWEB)

    TerraTek, A Schlumberger Company

    2008-12-31

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill 'faster and deeper' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the 'ultra-high rotary speed drilling system' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm - usually well below 5,000 rpm. This document provides the progress through two phases of the program entitled 'Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling' for the period starting 30 June 2003 and concluding 31 March 2009. The accomplishments of Phases 1 and 2 are summarized as follows: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance (see Black and Judzis); (2) TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed; (3) TerraTek concluded small-scale cutting performance tests; (4

  6. Groundwater Quality Assessment in hard rock terrain of Rasipuram Taluk, Namakkal District

    Directory of Open Access Journals (Sweden)

    K.Ramesh,

    2016-02-01

    Full Text Available Groundwater is of most important to rural development in many countries of the world. Over exploitation of groundwater has become a major challenge not only to the present civilization and also for the future generations. The main focus of this study is to assess the suitability of groundwater quality for drinking and irrigation purposes in vicinity of Rasipuram block in Tamil Nadu. Groundwater samples from 15 locations were collected from different wells during January 2015 and analyzed for different physico-chemical parameters. The usefulness of these parameters in predicting groundwater quality characteristics were discussed. The quality of groundwater in the study area is fresh to brackish water, moderately hard to very hard in nature. The piper plot shows that the most of the groundwater samples fall in the field of Na+ -Cland mixed Ca++ -Na+ -Cltype. Water quality index rating was carried out to quantify overall groundwater quality status of the area. The WQI for these samples ranges from 37.34 to 650. Hence majority of the water samples are poor to very poor in water quality. The area in general is characterized by hard water, hence is not suitable for drinking purpose. The samples plotted in the piper and USSL diagram were used to understand the chemical characteristic of groundwater for irrigation purposes. However, the values of SAR, Na% and RSC indicate that groundwater is suitable for irrigation purposes. Overall water quality of the study area was found satisfactory for drinking purpose except in few locations and suitable for irrigation purpose. Hence the local government needs to initiate remedial measures.

  7. Epistemic uncertainty and limitations of the κ0 model for near-surface attenuation at hard rock sites

    Science.gov (United States)

    Edwards, Benjamin; Ktenidou, Olga-Joan; Cotton, Fabrice; Abrahamson, Norman; Van Houtte, Chris; Fäh, Donat

    2015-09-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030-3000 m s-1) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κr. The κr values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κr which can be split into two groups: broad-band methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common data sets. In our first step we examine the variability of the individual measured κr values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κr due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κr attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects [e.g. Q( f )]: since the κr model is implicitly frequency independent, κr will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κr data sets from the five approaches, we investigate

  8. Epistemic Uncertainty and Limitations of the Kappa0 model for Near-surface Attenuation at Hard Rock Sites

    Science.gov (United States)

    Edwards, Benjamin

    2016-04-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030 to 3000 m/s) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κ. The κ values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κ which can be split into two groups: broadband methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common datasets. In our first step we examine the variability of the individual measured κ values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κ due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κ attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects (e.g., Q(f)): since the κ model is implicitly frequency independent, κ will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κ datasets from the five approaches, we investigate the

  9. Assessing the role of cation exchange in controlling groundwater chemistry during fluid mixing in fractured granite at Aespoe, Sweden

    International Nuclear Information System (INIS)

    Geochemical modeling was used to simulate the mixing of dilute shallow groundwater with deeper more saline groundwater in the fractured granite of the Redox Zone at the Aespoe underground Hard Rock Laboratory (HRL). Fluid mixing simulations were designed to assess the role that cation exchange plays in controlling the composition of fluids entering the HRL via fracture flow. Mixing simulations included provision for the effects of mineral precipitation and cation exchange on fluid composition. Because the predominant clay mineral observed in fractures in the Redox Zone has been identified as illite or mixed layer illite smectite, an exchanger with the properties of illite was used to simulate cation exchange. Cation exchange on illite was modeled using three exchange sites, a planar or basal plane site with properties similar to smectite, and two edge sites that have very high affinities for K, Rb, and Cs. Each site was assumed to obey an ideal Vanselow exchange model, and exchange energies for each site were taken from the literature. The predicted behaviors of Na, Ca, and Mg during mixing were similar to those reported in a previous study in which smectite was used as the model for the exchanger. The trace elements Cs and Rb were predicted to be strongly associated with the illite exchanger, and the predicted concentrations of Cs in fracture fill were in reasonable agreement with reported chemical analyses of exchangeable Cs in fracture fill. The results of the geochemical modeling suggest that Na, Ca, and Sr concentrations in the fluid phase may be controlled by cation exchange reactions that occur during mixing, but that Mg appears to behave conservatively. There is currently not enough data to make conclusions regarding the behavior of Cs and Rb

  10. In situ heating experiments in hard rock: their objectives and design

    International Nuclear Information System (INIS)

    Of the many alternatives that are being considered for the disposal of nuclear wastes, deep underground burial is favored. The wealth of experience concerning the design and construction of underground excavations does not include the unique effects of heating excavations by radioactive decay, nor the issue of long-term isolation. The effects of heating are important in establishing the feasibility of this method of disposal and are essential for the design of an underground repository. Near-field phenomena around individual canisters can be studied by full-scale experiments, using electrical heaters. The thermal diffusivity of rock is so low that information concerning the interaction between full-scale heaters and of the effects of heating a large volume of rock cannot be measured in full-scale experiments lasting less than a few decades. To overcome this difficulty, a time-scaled heating experiment has been developed in which a reduction in linear scale is accompanied by an acceleration of the time scale to the second power. In this experiment, the linear scale is about a third, so that the time scale is about ten fold

  11. Assessment of groundwater quality for drinking and irrigation use in shallow hard rock aquifer of Pudunagaram, Palakkad District Kerala

    Science.gov (United States)

    Satish Kumar, V.; Amarender, B.; Dhakate, Ratnakar; Sankaran, S.; Raj Kumar, K.

    2016-06-01

    Groundwater samples were collected for pre-monsoon and post-monsoon seasons based on the variation in the geomorphological, geological, and hydrogeological factors for assessment of groundwater quality for drinking and irrigation use in a shallow hard rock aquifer of Pudunagaram area, Palakkad district, Kerala. The samples were analyzed for various physico-chemical parameters and major ion chemistry. Based on analytical results, Gibbs diagram and Wilcox plots were plotted and groundwater quality has been distinguished for drinking and irrigation use. Gibbs diagram shows that the samples are rock dominance and controlling the mechanism for groundwater chemistry in the study area, while Wilcox plot suggest that most of the samples are within the permissible limit of drinking and irrigation use. Further, the suitability of water for irrigation was determined by analyzing sodium adsorption ratio, residual sodium carbonate, sodium percent (%Na), Kelly's ratio, residual sodium carbonate, soluble sodium percentage, permeability index, and water quality index. It has been concluded that, the water from the study area is good for drinking and irrigation use, apart few samples which are exceeding the limits due to anthropogenic activities and those samples were indisposed for irrigation.

  12. Heat-energy storage through semi-opened circulation into low-permeability hard-rock aquifers

    Science.gov (United States)

    Pettenati, Marie; Bour, Olivier; Ausseur, Jean-Yves; de Dreuzy, Jean-Raynald; de la Bernardie, Jérôme; Chatton, Eliot; Lesueur, Hervé; Bethencourt, Lorine; Mougin, Bruno; Aquilina, Luc; Koch, Florian; Dewandel, Benoit; Boisson, Alexandre; Mosser, Jean-François; Pauwels, Hélène

    2016-04-01

    In low-permeability environments, the solutions of heat storage are still limited to the capacities of geothermal borehole heat exchangers. The ANR Stock-en-Socle project explores the possibilities of periodic storage of sensitive heat1 in low-permeability environments that would offer much better performance than that of borehole heat exchangers, especially in terms of unit capacity. This project examines the storage possibilities of using semi-open water circulation in typically a Standing Column Well (SCW), using the strong heterogeneity of hard-rock aquifers in targeting the least favorable areas for water resources. To solve the main scientific issues, which include evaluating the minimum level of permeability required around a well as well as its evolution through time (increase and decrease) due to water-rock interaction processes, the study is based on an experimental program of fieldwork and modelling for studying the thermal, hydraulic and geochemical processes involved. This includes tracer and water-circulation tests by injecting hot water in different wells located in distinct hard-rock settings (i.e. granite and schist) in Brittany, Ploemeur (H+ observatory network) and Naizin. A numerical modelling approach allows studying the effects of permeability structures on the storage and heat-recovery capacities, whereas the modelling of reactive transfers will provide an understanding of how permeability evolves under the influence of dissolution and precipitation. Based on the obtained results, technical solutions will be studied for constructing a well of the SCW type in a low-permeability environment. This work will be completed by a technical and economic feasibility study leading to an investment and operations model. This study aims to describe the suitability of SCW storage for shallow geothermal energy. In order to reach these objectives, Stock-en-Socle is constructed around a public/private partnership between two public research organizations, G

  13. Evidence for matrix diffusion in the True-1 block at Aespoe based on fracture characterisation and modelling of tracer tests

    International Nuclear Information System (INIS)

    In situ tracer tests using uranin and differently sorbing radiotracers over distances of metres in fractured granitic rock were conducted in the Aespoe Hard Rock Laboratory (Sweden) at 400 m below surface. These tests were accompanied by: (1) a detailed structural and petrological characterisation of the test volume, and (2) a modelling effort to identify the most relevant transport and retardation processes and to constrain parameter values. Due to the short duration of the experiments (hours-days), tracers interact with a very limited volume of the rock, and thus tracer retardation due to matrix diffusion and sorption may occur exclusively in the fracture-filling fault rocks, specifically in fault gouge and, to a lesser extent, in adjacent cataclasite. On the other hand, the unaltered and undeformed bulk rock is not expected to interact noticeably with the tracers over the timescales of the experiments. The flow field was characterised on the basis of a simple 2-D-stream-tube formalism with an underlying homogeneous and isotropic transmissivity field. Tracer transport was modelled applying the dual porosity medium approach, which is linked to the flow part of the model by the flow porosity. Calibration of the model was done using the data from one single uranin breakthrough (PDT3). The analysis of the PDT3 test clearly showed that matrix diffusion had to be included in the model, evidenced by a characteristic shape of the breakthrough curve. Blind-predictions were made for the breakthrough curves of a number of tracers, considering advection/dispersion in fractures as well as limited matrix diffusion and sorption in fault gouge. After the disclosure of the measurements, the predictions were compared with the experimental findings and turned out to be very good for non-sorbing species but somewhat less precise for sorbing tracers, most likely due to the limited knowledge of the diffusion and sorption characteristics of fault gouge. It is concluded that matrix

  14. Groundwater recharge in a hard rock aquifer: A conceptual model including surface-loading effects

    Science.gov (United States)

    Rodhe, Allan; Bockgård, Niclas

    2006-11-01

    SummaryThe groundwater level in a fractured rock aquifer in Sweden was found to respond quickly to rainfall, although the bedrock was covered by 10-m-thick till soil. A considerable portion of the response was caused by surface loading, i.e., by the weight increase of the soil due to the addition of water from precipitation, whereas the rest reflected recharge. The hypothesis that the bedrock aquifer was recharged by vertical flow from groundwater in the overlying soil was tested with a simple recharge model, in which the bedrock-groundwater levels were simulated from the soil-groundwater and estimated surface-loading variation. The model had three parameters: the ratio between the equivalent vertical hydraulic conductivity governing the recharge and the storage coefficient of the bedrock reservoir, the recession coefficient for the bedrock-groundwater level, and the bedrock-groundwater level at which the outflow ceases. The model could be reasonably well calibrated and validated to head observations in one of two boreholes. The fit to the seasonal variation was similar when calibrating the model with or without surface loading, but surface loading had to be included to properly simulate individual recharge events. The relative temporal variation in the fluxes could be determined by the calibration. The variation in the recharge was from -10% to +25% in relation to the mean flux. The variation in the discharge was only ±1%. By applying a storage coefficient of the reservoir of 5 × 10 -4, the simulated mean recharge was about 20 mm yr -1. The results support the hypothesis that the bedrock-groundwater at the site is fed by local recharge from the overlying soil aquifer.

  15. Choosing between rocks, hard places and a lot more. The economic interface

    International Nuclear Information System (INIS)

    decisions: for deciding whether or not to explore or develop, for choosing between exploration prospects ('rocks') in a licensing round, for choosing between basins or countries ('places') in which one wants to explore and produce, and for choosing between development concepts, recovery mechanisms, plateau rates, ... (and a lot more), in field development planning. Due to the largely unpredictable nature of the subsurface and the future oil price, the concepts of 'risk' (=possibility of a financial loss or an unachieved objective) and unfortunately, to a lesser extent 'grisk' (possibility of a financial gain in excess of the objective) are quite central in the oil business. Illustrations of 'risk' and 'grisk' will be presented. 24 refs

  16. A multivariate statistical approach to identify the spatio-temporal variation of geochemical process in a hard rock aquifer.

    Science.gov (United States)

    Thivya, C; Chidambaram, S; Thilagavathi, R; Prasanna, M V; Singaraja, C; Adithya, V S; Nepolian, M

    2015-09-01

    A study has been carried out in crystalline hard rock aquifers of Madurai district, Tamil Nadu, to identify the spatial and temporal variations and to understand sources responsible for hydrogeochemical processes in the region. Totally, 216 samples were collected for four seasons [premonsoon (PRM), southwest monsoon (SWM), northeast monsoon (NWM), and postmonsoon (POM)]. The Na and K ions are attributed from weathering of feldspars in charnockite and fissile hornblende gneiss. The results also indicate that monsoon leaches the U ions in the groundwater and later it is reflected in the (222)Rn levels also. The statistical relationship on the temporal data reflects the fact that Ca, Mg, Na, Cl, HCO3, and SO4 form the spinal species, which are the chief ions playing the significant role in the geochemistry of the region. The factor loadings of the temporal data reveal the fact that the predominant factor is anthropogenic process and followed by natural weathering and U dissolution. The spatial analysis of the temporal data reveals that weathering is prominent in the NW part and that of distribution of U and (222)Rn along the NE part of the study area. This is also reflected in the cluster analysis, and it is understood that lithology, land use pattern, lineaments, and groundwater flow direction determine the spatial variation of these ions with respect to season. PMID:26239570

  17. Modeling of the Influence of the Swedish Äspö Hard Rock Laboratory (HRL) on Groundwater Flow

    Science.gov (United States)

    Gylling, B.; Hartley, L.; Rhen, I.; Selroos, J.

    2008-12-01

    Three-dimensional, regional, numerical models of groundwater flow and solute transport in fractured crystalline rock are used for two sites in Sweden that are considered for geological disposal of spent nuclear fuel. As a part of the site descriptive modeling for one of the sites, Laxemar, a number of simulations have been carried out to investigate if the Äspö Hard Rock Laboratory (HRL), an approximately 450 m deep tunnel below the island of Äspö located outside the Laxemar area, has an impact on the groundwater flow situation at Äspö and Laxemar. In the reference case, a specified head boundary condition was set on the top surface. For this study, two simulations were performed for each set of hydraulic properties and boundary conditions considered: one with the Äspö HRL present and water abstracted according to the inflow rates measured in the tunnel weirs; and a simulation under undisturbed conditions. In both simulations, the calculations start at 1960 using appropriate models of palaeo-hydrogeology without any disturbance for the initial condition and then the models are run until 2006 with a one year time-step. The cases were compared in terms of modeled drawdown, and changes to the Darcy velocity and hydro-geochemistry. Sensitivities of the results were considered in relation to the top surface boundary condition including a maximum infiltration of 165 mm/year or 80 m/year, and varying the hydraulic contact between the sea and the bedrock beneath. A number of comparisons with field data can be made to assess which of the variants is considered to best reflect site conditions and to possibly inform future developments of the site descriptive model. Drawdown measurements are available for several percussion drilled boreholes. Data are also available for salinity of the water collected in the weirs within the tunnel. Essentially, this can be used as a long-term interference test with the Äspö HRL as the sink and the percussion drilled boreholes as

  18. Aespoe Pillar Stability Experiment. Summary of preparatory work and predictive modelling

    International Nuclear Information System (INIS)

    The Aespoe Pillar Stability Experiment, APSE, is a large scale rock mechanics experiment for research of the spalling process and the possibility for numerical modelling of it. The experiment can be summarized in three objectives: Demonstrate the current capability to predict spalling in a fractured rock mass; Demonstrate the effect of backfill (confining pressure) on the rock mass response; and Comparison of 2D and 3D mechanical and thermal predicting capabilities. This report is a summary of the works that has been performed in the experiment prior to the heating of the rock mass. The major activities that have been performed and are discussed herein are: 1) The geology of the experiment drift in general and the experiment volume in particular. 2) The design process of the experiment and thoughts behind some of the important decisions. 3) The monitoring programme and the supporting constructions for the instruments. 4) The numerical modelling, approaches taken and a summary of the predictions. In the end of the report there is a comparison of the results from the different models. Included is also a comparison of the time needed for building, realizing and make changes in the different models

  19. Surface-groundwater interactions in hard rocks in Sardon Catchment of western Spain: An integrated modeling approach

    Science.gov (United States)

    Hassan, S. M. Tanvir; Lubczynski, Maciek W.; Niswonger, Richard G.; Su, Zhongbo

    2014-09-01

    The structural and hydrological complexity of hard rock systems (HRSs) affects dynamics of surface-groundwater interactions. These complexities are not well described or understood by hydrogeologists because simplified analyses typically are used to study HRSs. A transient, integrated hydrologic model (IHM) GSFLOW (Groundwater and Surface water FLOW) was calibrated and post-audited using 18 years of daily groundwater head and stream discharge data to evaluate the surface-groundwater interactions in semi-arid, ∼80 km2 granitic Sardon hilly catchment in Spain characterized by shallow water table conditions, relatively low storage, dense drainage networks and frequent, high intensity rainfall. The following hydrological observations for the Sardon Catchment, and more generally for HRSs were made: (i) significant bi-directional vertical flows occur between surface water and groundwater throughout the HRSs; (ii) relatively large groundwater recharge represents 16% of precipitation (P, 562 mm.y-1) and large groundwater exfiltration (∼11% of P) results in short groundwater flow paths due to a dense network of streams, low permeability and hilly topographic relief; deep, long groundwater flow paths constitute a smaller component of the water budget (∼1% of P); quite high groundwater evapotranspiration (∼5% of P and ∼7% of total evapotranspiration); low permeability and shallow soils are the main reasons for relatively large components of Hortonian flow and interflow (15% and 11% of P, respectively); (iii) the majority of drainage from the catchment leaves as surface water; (iv) declining 18 years trend (4.44 mm.y-1) of groundwater storage; and (v) large spatio-temporal variability of water fluxes. This IHM study of HRSs provides greater understanding of these relatively unknown hydrologic systems that are widespread throughout the world and are important for water resources in many regions.

  20. Vertical anisotropy of hydraulic conductivity in fissured layer of hard-rock aquifers due to the geological structure of weathering profiles

    OpenAIRE

    Maréchal, Jean-Christophe; Wyns, Robert; Lachassagne, Patrick; Subrahmanyam, K.; Touchard, Frédéric

    2003-01-01

    Pumping tests carried out in the fissured layer of a granitic hard-rock aquifer, interpreted at the observation wells by means of the analytical solution of Neuman and at the pumping wells with that of Gringarten show the existence of a strong vertical anisotropy of this layer of the aquifer; the horizontal permeability is clearly and systematically higher than the vertical permeability. These results agree perfectly with the geological observations, the fissured layer of the weathered granit...

  1. The European Hard Rock and Heavy Metal live music market A closer look at the development of emerging bands through live performing

    OpenAIRE

    Garzon Jimenez, Juan David

    2015-01-01

    The present study is set out to provide a better understanding of the current situation regarding career development in terms of live performing for emerging Hard Rock / Heavy Metal (HR/HM) bands in Europe, and to find out how these bands have been impacted by changes in the live-music economy. Previous research conducted concerning the live music industry mostly consists of overall figures and general turnover over years. Such research is segmented only by country, and main...

  2. Assessing and modelling hard rock aquifer recharge based on complementary methodologies : a case study in the Gabbros of Beja Aquifer System, South Portugal

    OpenAIRE

    Paralta, Eduardo; Oliveira, M.

    2005-01-01

    The "Gabbros of Beja" Aquifer System extends for approximately 350 km2 and is one of the most important reservoirs of groundwater in the context of hard rocks aquifers of South Portugal (Alentejo Region). The average annual rainfall in the area is about 500 to 600 mm. Groundwater resources are used for public supply over 3 councils and irrigation. During drought cycles consumption increases and pumping rates decrease with correspondent management difficulties and conflicts between private ...

  3. Review: Natural tracers in fractured hard-rock aquifers in the Austrian part of the Eastern Alps—previous approaches and future perspectives for hydrogeology in mountain regions

    Science.gov (United States)

    Hilberg, Sylke

    2016-03-01

    Extensive in-depth research is required for the implementation of natural tracer approaches to hydrogeological investigation to be feasible in mountainous regions. This review considers the application of hydrochemical and biotic parameters in mountain regions over the past few decades with particular reference to the Austrian Alps, as an example for alpine-type mountain belts. A brief introduction to Austria's hydrogeological arrangement is given to show the significance of fractured hard-rock aquifers for hydrogeological science as well as for water supply purposes. A literature search showed that research concerning fractured hard-rock aquifers in Austria is clearly underrepresented to date, especially when taking the abundance of this aquifer type and the significance of this topic into consideration. The application of abiotic natural tracers (hydrochemical and isotope parameters) is discussed generally and by means of examples from the Austrian Alps. The potential of biotic tracers (microbiota and meiofauna) is elucidated. It is shown that the meiofauna approach to investigating fractured aquifers has not yet been applied in the reviewed region, nor worldwide. Two examples of new approaches in mountainous fractured aquifers are introduced: (1) use of CO2 partial pressure and calcite saturation of spring water to reconstruct catchments and flow dynamics (abiotic approach), and, (2) consideration of hard-rock aquifers as habitats to reconstruct aquifer conditions (biotic approach).

  4. Review: Natural tracers in fractured hard-rock aquifers in the Austrian part of the Eastern Alps—previous approaches and future perspectives for hydrogeology in mountain regions

    Science.gov (United States)

    Hilberg, Sylke

    2016-08-01

    Extensive in-depth research is required for the implementation of natural tracer approaches to hydrogeological investigation to be feasible in mountainous regions. This review considers the application of hydrochemical and biotic parameters in mountain regions over the past few decades with particular reference to the Austrian Alps, as an example for alpine-type mountain belts. A brief introduction to Austria's hydrogeological arrangement is given to show the significance of fractured hard-rock aquifers for hydrogeological science as well as for water supply purposes. A literature search showed that research concerning fractured hard-rock aquifers in Austria is clearly underrepresented to date, especially when taking the abundance of this aquifer type and the significance of this topic into consideration. The application of abiotic natural tracers (hydrochemical and isotope parameters) is discussed generally and by means of examples from the Austrian Alps. The potential of biotic tracers (microbiota and meiofauna) is elucidated. It is shown that the meiofauna approach to investigating fractured aquifers has not yet been applied in the reviewed region, nor worldwide. Two examples of new approaches in mountainous fractured aquifers are introduced: (1) use of CO2 partial pressure and calcite saturation of spring water to reconstruct catchments and flow dynamics (abiotic approach), and, (2) consideration of hard-rock aquifers as habitats to reconstruct aquifer conditions (biotic approach).

  5. Statistical patterns of geochemistry in crystalline rock and effect of sorption kinetics on radionuclide migration

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shulan; Woerman, A. [Uppsala Univ. (Sweden). Dept. of Earth Sciences

    1998-09-01

    The overall objective of the current project is to develop a quantitative understanding of the effects of spatial variability in physical and geochemical properties of the rock on the migration of radionuclides along a single fracture in crystalline rock. The strategy is first to deduce the basic geostatistics of the main model parameters by means of detailed laboratory (batch) experiments on a large number of rock samples taken from Swedish crystalline basement. The results are then analysed by geostatistical methods and used for stochastic interpretations of a series of laboratory migration experiments to be conducted in a later phase of the project. In an earlier phase of the project, a new mathematical model was developed as a basis for the interpretation of experimental results and the generalisation to performance assessment analyses. The model describes migration of radionuclides along a two-dimensional fracture and includes the transversal diffusion into the rock matrix and surface. To be able to discriminate between the effects of parameter heterogeneity and potential effects of kinetics, a model description has also been developed for first-order sorption kinetics. The main model parameters are represented as spatially random. This report contains results from the batch tests and the geostatistical analysis and the progress of the model formulation for transport of radionuclides. Geostatistics of the main parameters was experimentally determined for two rock types, Aespoe diorite, and Smaaland granite. Drill cores were collected at the Aespoe Hard Rock Laboratory and sawn into a large number of slabs. The porosity, the effective diffusivity and the adsorption characteristics were determined using various experimental methods on the individual pieces. Semi-variograms show that both porosity and effective diffusivity are correlated over a separation distance of 30 to 40 cm. The coefficients of variation of the porosity of rock samples with a size of 20x20

  6. Site investigations: Strategy for rock mechanics site descriptive model

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

  7. Site investigations: Strategy for rock mechanics site descriptive model

    International Nuclear Information System (INIS)

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate

  8. A contribution to open pit hard coal mine waste rock management : comparing sidehill fill with layered dumping

    OpenAIRE

    Ahmad, Shakeel

    2013-01-01

    Coal mining is an important economic activity as it covers the energy demands, generates export revenues and creates employment opportunities. Mining can, however, impact the local environment. Different mining operations produce several types of waste materials and one of the major wastes produced by open-pit mines is waste rock, which is dumped at waste rock dumps. The waste rock dumps can impact the environment in several ways. For instance, in Vietnam open-pit mines have disturbed the bea...

  9. Groundwater targeting in a hard-rock terrain using fracture-pattern modeling, Niva River basin, Andhra Pradesh, India

    Science.gov (United States)

    Srinivasa Rao, Y.; Reddy, T. V. K.; Nayudu, P. T.

    2000-09-01

    In hard-rock terrain, due to the lack of primary porosity in the bedrock, joints, fault zones, and weathered zones are the sources for groundwater occurrence and movement. To study the groundwater potential in the hard-rock terrain and drought-prone area in the Niva River basin, southern Andhra Pradesh state, India, Landsat 5 photographic data were used to prepare an integrated hydrogeomorphology map. Larsson's integrated deformation model was applied to identify the various fracture systems, to pinpoint those younger tensile fracture sets that are the main groundwater reservoirs, and to understand the importance of fracture density in groundwater prospecting. N35°-55°E fractures were identified as tensile and N35°-55°W fractures as both tensile and shear in the study area. Apparently, these fractures are the youngest open fractures. Wherever N35°-55°E and N35°-55°W fracture densities are high, weathered-zone thickness is greater, water-table fluctuations are small, and well yields are high. Groundwater-potential zones were delineated and classified as very good, good to very good, moderate to good, and poor. Résumé. Dans les roches de socle, l'absence de porosité primaire dans la roche fait que les fractures, les zones de faille et les zones d'altération sont les sites où l'eau souterraine est présente et s'écoule. Pour étudier le potentiel en eau souterraine dans la région de socle sujette à la sécheresse du bassin de la rivière Niva (sud de l'État d'Andhra Pradesh, Inde), des données photographiques de Landsat 5 ont été utilisées pour préparer une carte hydro-géomorphologique. Le modèle intégré de déformation de Larssons a été mis en œuvre pour identifier les différents systèmes de fractures, pour mettre l'accent sur les ensembles de fractures en extension les plus jeunes qui constituent les principaux réservoirs d'eau souterraine, et pour comprendre l'importance de la densité de fractures pour la prospection de l

  10. Overall evaluation of the modelling of the TRUE-1 tracer tests - Task 4. The Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes

    International Nuclear Information System (INIS)

    The Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. The task was carried out in 1995-2000 and consisted of several modelling exercises in support of the TRUE-1 tracer tests, including predictive modelling where experimental results were not available beforehand. This report presents an overall evaluation of the achievements of Task 4. The specific objectives of the overall evaluation were to highlight innovative and successful modelling approaches developed, to assess the stages of the task which proved most beneficial for conceptual understanding of transport processes at the TRUE-1 site and to assess the success of various steering tools. A concise summary of scientific achievements is given and conclusions drawn with respect to unresolved technical issues. Recommendations are presented that can optimise the management of future modelling tasks

  11. Combining hydrologic and geologic data to determine recharge areas in hard rocks, an example from the Eastern Alps, Austria

    Science.gov (United States)

    Staunig, R.; Winkler, G.; Birk, S.; Poltnig, W.

    2009-04-01

    Tectonic structures as faults and/or fault zones and slope tectonics take a great influence on water flow in hard rocks. They may represent hydraulic barriers or conduits, or a combination of both. Accurate predictions of water flow is often a critical aspect e.g. in tunnel design, the long-term stability of dams, and especially for determining recharge areas of springs as related to water quality protection. The discharge rates in respect to the topographic divided areas of springs (catchments) provide the understanding of the drainage directions of complex hydrogeologic systems. To determine the recharge areas (areas surrounded by groundwater-divides) the structural geologic data analysing the tectonics and the slope tectonics have also to be considered. With a conceptual approach hydrologic and structural geologic data were combined to determine recharge areas of springs draining a carbonatic fractured aquifer. The investigation area belongs to the Sattnitz-Conglomerate-Plateau extending in the north of and parallel to the Karawanken mountain range as a tableland in the south of the Klagenfurter Basin. The investigation area is the western part of the Sattnitz-Conglomerate-plateau built up by carbonatic conglomerates with a thickness up to 200 m and an extent of approximately 6 km². The conglomerates are of pliocene age and are composed of coarse grained, mainly carbonatic components cemented with a carbonatic matrix. The plateau is completely underlayed by a premesozoic crystalline basement and grained miocene silt and clay sediments containing coal layers as a permanent aquicludefine. The area has no streams and drains mainly to the west and north over several springs. The major springs were equipped with data loggers measuring continuously discharge, electric conductivity and temperature over several years. The major spring, its discharge rangs between approximately 25 l/s to more than 400 l/s, is situated in the northwest of the investigation area and

  12. Investigating the impact of global climatic and landuse changes on groundwater resources in hard rock areas of South India

    Science.gov (United States)

    Ferrant, S.; Perrin, J.; Marechal, J.; Dewandel, B.; Aulong, S.; Ahmed, S.

    2010-12-01

    In most parts of India, and particularly in South India, groundwater levels are hazardously declining, while agricultural groundwater use is increasing. The current issue is to address the probable evolution of water table levels in relation with climate and agricultural changes. The aim of the SHIVA-ANR project (http://www.shiva-anr.org) is to provide some indicators of the water availability at the village scale to evaluate the vulnerability of farmers facing global changes. This study focuses on a particularly water stressed semi-arid area of South India characterized by hard rock geology with naturally low recharge capacity and limited surface water availability. The study catchment is located in the agricultural area of the Kudaliar river watershed (980km^2) located 50 km north of Hyderabad, India. It is composed of about 120 villages. Socio economic surveys have been carried out at the village scale to evaluate the present socio-economic situation of farmers. It also provides more details on various cultural and irrigation practices at this scale. The landuse has been evaluated by remote sensing with two satellite images, one after monsoon (October 2009), and the other during dry season (March 2010). Groundwater-irrigated rice paddies represent about 10% of the area, whereas rainfed crop (corn and cotton) represent about 45%. Numerous small tanks (reservoir) situated on the river network define a water harvesting system of 2% of the catchment area which captures surface runoff during monsoon. No discharges data are available at the outlet, as the river is dry most of the year. A hydro-geological survey has been carried out to provide a map of aquifer thickness and the general state of the groundwater level before and after monsoon. The Soil Water Assessment Tool model (SWAT) has been calibrated to assess the water budget of the agricultural catchment under present conditions. Soil parameters calibration is made first on seasonal groundwater recharge for

  13. Proceedings of the fifth international groundwater conference on the assessment and management of groundwater resources in hard rock systems with special reference to basaltic terrain

    International Nuclear Information System (INIS)

    Groundwater resources in hard rock regions with limited renewable potential have to be managed judiciously to ensure adequate supplies of dependable quantity and quality. It is a natural resource with economic, strategic and environmental value, which is under stress both due to changing climatic and anthropogenic factors. Therefore the management strategies need to be aimed at sustenance of this limited resource. In India, and also elsewhere in the world major parts of the semi-arid regions are characterized by hard rocks and it is of vital importance to understand the nature of the aquifer systems and its current stress conditions. Though the achievements through scientific development in exploration and exploitation are commendable, it has adversely affected the hard rock aquifer system, both in terms of quantity and quality; which is of major concern today. In order to reverse the situation, better management strategy of groundwater resources needs to be devised for prevention of further degradation of quality and meeting out the future demand of quantity. This necessitates: understanding the flow mechanism, evaluating the potential and evolving optimal utilization schemes, and assessing and monitoring quality in the changing scenario of anthropogenically induced agricultural, urban, industrial and climatic change. The groundwater flow mechanism through fractures in hard rocks is yet to be fully understood in terms of fracture geometry and its relation to groundwater flow. The characterization of flow geometry in basaltic aquifer is yet to be fully explored. Groundwater pollution due to anthropogenic factors is very slow process with long-term impacts on carbon cycle and global climatic change on one hand and quality on the other. It is generally recognized that the prevention of groundwater pollution is cheaper than its remedial measures in the long run. Furthermore, because of the nature of groundwater flow and the complexity and management uncertainty of

  14. P-wave velocity changes in freezing hard low-porosity rocks: a laboratory-based time-average model

    Directory of Open Access Journals (Sweden)

    D. Draebing

    2012-02-01

    Full Text Available P-wave refraction seismics is a key method in permafrost research but its applicability to low-porosity rocks, that constitute alpine rock walls, has been denied in prior studies. These explain p-wave velocity changes in freezing rocks exclusively due to changing velocities of pore infill, i.e. water, air and ice. In existing models, no velocity increase is expected for low-porosity bedrock. We postulate, that mixing laws apply for high-porosity rocks, but freezing in confined space in low-porosity bedrock also alters physical rock matrix properties. In the laboratory, we measured p-wave velocities of 22 decimeter-large low-porosity (<6 % metamorphic, magmatic and sedimentary permafrost rock samples with a natural texture (>100 micro-fissures from 25 °C to –15 °C in 0.3 °C increments close to the freezing point. P-wave velocity increases by 7–78 % when freezing parallel to cleavage/bedding and matrix velocity increases from 5–59 % coincident to an anisotropy decrease in most samples. The expansion of rigid bedrock upon freezing is restricted and ice pressure will increase matrix velocity and decrease anisotropy while changing velocities of the pore infill are insignificant. Here, we present a modified Timur's 2-phase equation implementing changes in matrix velocity dependent on lithology and demonstrate the physical basis for refraction seismics in low-porosity bedrock.

  15. Model 96 of the Aespoe site. Results of prediction and outcome based on surface and underground bore hole investigations

    International Nuclear Information System (INIS)

    The site characterisation work of the bedrock around Aespoe has been carried out as an interdisciplinary work in the fields of geology, hydrogeology and hydrochemistry. It has been carried out in different steps focusing on different scales simultaneously. The descriptions have been focused on regional, site and block scales representing areas/volumes of 10x20 km, 500x500x500 m and 50x50x50 m respectively during the pre-construction phase. During the tunnel construction phase the models have been focusing scales of 0-10, 10-100 and 100-1000 metres. The models after the pre-investigation stage were the base for predictions of geological, rock mechanical, hydrogeological and hydrochemical conditions along the planned tunnel for the Aespoe HRL. During construction of the tunnel geological and hydrogeological mapping were made and comprehensive investigation were performed to get geological, rock mechanical, hydrogeological and hydrochemical conditions which could be compared to the predicted. One objective was to test the ability to obtain a thorough understanding of the rock conditions based on investigations of the surface and investigations in and between bore holes from the surface. By 'understanding' we here mean to obtain sufficient knowledge to show how things are, but also to show how things cannot be. An important part of the comparison of the predictions with the outcome was to evaluate the usefulness and feasibility of pre-investigation methods. (Discussed in an other contribution to this conference). Another purpose was to evaluate the models made. This is discussed in the present contribution

  16. Examination of the Excavation Damaged Zone in the TASS tunnel, Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Mats (Swebrec, Luleaa Univ. of Technology, Luleaa (Sweden)); Markstroem, Ingemar; Pettersson, Anders; Straeng, Malin (Golder Associates, Uppsala (Sweden))

    2009-10-15

    The question of an existing continuous Excavation Damage Zone (EDZ) is very important for SKB. Is it possible to use drilling and blasting in the planned repository for spent nuclear fuel? Could fractures from blasting form a continuous EDZ? In order to increase the understanding of the EDZ and the possibility of an existing continuous EDZ along the deposition tunnel, SKB decided to examine the fracturing in a selected area of the TASS tunnel and to create a 3D model of the fractures in the investigated area. It was of special interest to study the transition zones between the blast rounds to examine if the EDZ from the bottom charges could form a continuous EDZ from one round to another. The TASS-tunnel is situated at the 450-m level in the Aespoe Hard Rock Laboratory. The tunnel, with a cross-section area of 20 m2, was planned to be 90 m long. In a subproject called Excavation the purpose was to test different plans for drilling, charging and initiation in order to give recommendations on how the final repository of spent fuel should be excavated. The test methodology used in this investigation comprised the following steps: selecting test area, drilling and wire sawing of blocks, surveying the blocks, removal and transportation of the blocks to the surface, cutting the blocks into slabs, fracture identification with penetrants, positioning and photographing the slabs, digitizing and 3D modelling of the fractures. The test area for EDZ consisted of an 8 m long and 1.5 m high section in excavation sequence no 4. The selected section covered the end of round 9, the entire round 10 and the start of round 11. In the contour and the helpers small diameter charges for smooth blasting were used (decoupled charges). These charges also have a relatively low detonation velocity (VOD) and this, together with the decoupling, gives short fracture lengths i.e. a small EDZ. The contour holes and the helpers were initiated with electronic detonators to achieve a simultaneous

  17. Examination of the Excavation Damaged Zone in the TASS tunnel, Aespoe HRL

    International Nuclear Information System (INIS)

    The question of an existing continuous Excavation Damage Zone (EDZ) is very important for SKB. Is it possible to use drilling and blasting in the planned repository for spent nuclear fuel? Could fractures from blasting form a continuous EDZ? In order to increase the understanding of the EDZ and the possibility of an existing continuous EDZ along the deposition tunnel, SKB decided to examine the fracturing in a selected area of the TASS tunnel and to create a 3D model of the fractures in the investigated area. It was of special interest to study the transition zones between the blast rounds to examine if the EDZ from the bottom charges could form a continuous EDZ from one round to another. The TASS-tunnel is situated at the 450-m level in the Aespoe Hard Rock Laboratory. The tunnel, with a cross-section area of 20 m2, was planned to be 90 m long. In a subproject called Excavation the purpose was to test different plans for drilling, charging and initiation in order to give recommendations on how the final repository of spent fuel should be excavated. The test methodology used in this investigation comprised the following steps: selecting test area, drilling and wire sawing of blocks, surveying the blocks, removal and transportation of the blocks to the surface, cutting the blocks into slabs, fracture identification with penetrants, positioning and photographing the slabs, digitizing and 3D modelling of the fractures. The test area for EDZ consisted of an 8 m long and 1.5 m high section in excavation sequence no 4. The selected section covered the end of round 9, the entire round 10 and the start of round 11. In the contour and the helpers small diameter charges for smooth blasting were used (decoupled charges). These charges also have a relatively low detonation velocity (VOD) and this, together with the decoupling, gives short fracture lengths i.e. a small EDZ. The contour holes and the helpers were initiated with electronic detonators to achieve a simultaneous

  18. P-wave velocity changes in freezing hard low-porosity rocks: a laboratory-based time-average model

    Directory of Open Access Journals (Sweden)

    D. Draebing

    2012-10-01

    Full Text Available P-wave refraction seismics is a key method in permafrost research but its applicability to low-porosity rocks, which constitute alpine rock walls, has been denied in prior studies. These studies explain p-wave velocity changes in freezing rocks exclusively due to changing velocities of pore infill, i.e. water, air and ice. In existing models, no significant velocity increase is expected for low-porosity bedrock. We postulate, that mixing laws apply for high-porosity rocks, but freezing in confined space in low-porosity bedrock also alters physical rock matrix properties. In the laboratory, we measured p-wave velocities of 22 decimetre-large low-porosity (< 10% metamorphic, magmatic and sedimentary rock samples from permafrost sites with a natural texture (> 100 micro-fissures from 25 °C to −15 °C in 0.3 °C increments close to the freezing point. When freezing, p-wave velocity increases by 11–166% perpendicular to cleavage/bedding and equivalent to a matrix velocity increase from 11–200% coincident to an anisotropy decrease in most samples. The expansion of rigid bedrock upon freezing is restricted and ice pressure will increase matrix velocity and decrease anisotropy while changing velocities of the pore infill are insignificant. Here, we present a modified Timur's two-phase-equation implementing changes in matrix velocity dependent on lithology and demonstrate the general applicability of refraction seismics to differentiate frozen and unfrozen low-porosity bedrock.

  19. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    International Nuclear Information System (INIS)

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  20. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Emmelin, Ann [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Eriksson, Magnus [Royal Inst. of Technology, Stockholm (Sweden); Fransson, Aasa [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2004-09-01

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  1. Preliminary results from water content and density measurements of the backfill and buffer in the prototype repository at Aespoe HRL

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Since 2001 the Prototype Repository at Aespoe Hard Rock Laboratory has been carried out as a large-scale experimental installation of the KBS-3 Swedish/Finnish concept for final disposal of spent nuclear fuel. The Prototype Repository consists of a total of six full-scale deposition holes with a centre distance of 6 m, located in a TBM tunnel at a depth of 450 m. Each deposition hole is fitted with a full-scale bentonite buffer, consisting of altogether 14 blocks and a full-scale canister, Figure 1. The canisters are equipped with heaters to simulate the heat from spent nuclear fuel. There are two sections of the installation; The inner section (I) consisting of four deposition holes (no. 1-4) with buffer and canister, and the outer section (II) consisting of two deposition holes (no. 5-6). The deposition tunnel is filled with a mixture of crushed rock and bentonite (30% of bentonite). A massive concrete plug, designed to withstand full water and swelling pressures, separates the test area from the open tunnel system and a second plug separates the two sections. This layout provides two more or less independent test sections. The outer section was opened and retrieved during 2011. The backfill was excavated with a back-hoe loader in layers of two metres. Samples were taken in these layers with the object of determining density and water content. Important items of the backfill to examine were the contact between backfill and the tunnel wall and the contact between the buffer and backfill in the deposition holes. The water content of the backfill was determined by drying samples in an oven at a temperature of 105 C for 24 h and the density was determined by weighting the sample both in air and merged into paraffin oil with known density. Altogether more than 900 tons of backfill material was excavated from the tunnel and more than 1100 samples, distributed over 11 sections, were taken for determining the water

  2. Accurate 3D point cloud comparison and volumetric change analysis of Terrestrial Laser Scan data in a hard rock coastal cliff environment

    Science.gov (United States)

    Earlie, C. S.; Masselink, G.; Russell, P.; Shail, R.; Kingston, K.

    2013-12-01

    Our understanding of the evolution of hard rock coastlines is limited due to the episodic nature and ';slow' rate at which changes occur. High-resolution surveying techniques, such as Terrestrial Laser Scanning (TLS), have just begun to be adopted as a method of obtaining detailed point cloud data to monitor topographical changes over short periods of time (weeks to months). However, the difficulties involved in comparing consecutive point cloud data sets in a complex three-dimensional plane, such as occlusion due to surface roughness and positioning of data capture point as a result of a consistently changing environment (a beach profile), mean that comparing data sets can lead to errors in the region of 10 - 20 cm. Meshing techniques are often used for point cloud data analysis for simple surfaces, but in surfaces such as rocky cliff faces, this technique has been found to be ineffective. Recession rates of hard rock coastlines in the UK are typically determined using aerial photography or airborne LiDAR data, yet the detail of the important changes occurring to the cliff face and toe are missed using such techniques. In this study we apply an algorithm (M3C2 - Multiscale Model to Model Cloud Comparison), initially developed for analysing fluvial morphological change, that directly compares point to point cloud data using surface normals that are consistent with surface roughness and measure the change that occurs along the normal direction (Lague et al., 2013). The surfaces changes are analysed using a set of user defined scales based on surface roughness and registration error. Once the correct parameters are defined, the volumetric cliff face changes are calculated by integrating the mean distance between the point clouds. The analysis has been undertaken at two hard rock sites identified for their active erosion located on the UK's south west peninsular at Porthleven in south west Cornwall and Godrevy in north Cornwall. Alongside TLS point cloud data, in

  3. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

    International Nuclear Information System (INIS)

    deal with spatial variability and data uncertainties of the modelling results, and in order to minimise the number of numerical models to run, Monte Carlo simulations are used. The methodology was tested in Sweden on a limited set of data coming from the Aespoe Hard Rock Laboratory. The mechanical properties of the rock mass were determined in two scales, (I) in a 550 m block in which 'ordinary rock units' and 'deformation zone units' are identified,and (II) in a box located at depth from -380 to -500 m,and divided in 30x30x30 m cubes

  4. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle; Fredriksson, Anders; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

    2002-05-01

    deal with spatial variability and data uncertainties of the modelling results, and in order to minimise the number of numerical models to run, Monte Carlo simulations are used. The methodology was tested in Sweden on a limited set of data coming from the Aespoe Hard Rock Laboratory. The mechanical properties of the rock mass were determined in two scales, (I) in a 550 m block in which 'ordinary rock units' and 'deformation zone units' are identified,and (II) in a box located at depth from -380 to -500 m,and divided in 30x30x30 m cubes.

  5. Simulations of pressure and salinity fields at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Loefman, J. [VTT Energy, Espoo (Finland)

    1997-04-01

    The primary objective of this study was to examine whether the geochemical field data from Aespoe could be interpreted and understood by means of numerical simulations for flow and transport. A site-specific simulation model for groundwater flow and salt transport was developed on the basis of the field investigations. Both steady-state and transient simulations of flow and transport were performed. In the transient simulations, land uplift and the effect of diffusion into/from the matrix blocks with stagnant water were taken into account. The computational results were evaluated on the basis of the experimental values for the pressure and salt concentration.

  6. Integrating gamma log and conventional electrical logs to improve identification of fracture zones in hard rocks for hydrofracturing: a case study from Ghana

    Science.gov (United States)

    Amartey, E. O.; Akiti, T. T.; Armah, T.; Osae, S.; Agyekum, W. A.

    2016-07-01

    Hydrofracturing of low-yielding boreholes in hard rocks is a widely used technique in Africa for improvement of yield, thus making them qualified for installation of a hand-pump for domestic water supply. However, the success rate of the hydrofracturing campaigns seems not to be that high as generally claimed by contractors. One reason amongst others might be that the selection of zones for hydrofracturing in the individual borehole is based on pre-hydrofracturing investigation using conventional electrical logs only. Thereby, the zones selected are the occurring resistivity minima interpreted as weak zones with some fracturing. However, resistivity minima can also be caused solely by lithological reasons, which then in most cases could have been seen on a gamma log as corresponding increased gamma radiation. The advantages of using gamma logging in combination with conventional electrical logging technique for prediction of fractured zones in basement rocks is illustrated by investigations of three low-yielding boreholes located in different geological environments in crystalline basement rocks in Ghana.

  7. SITE-94. Far-field rock mechanics modelling for nuclear waste disposal

    International Nuclear Information System (INIS)

    The objectives of the far-field rock mechanics study were to investigate the mechanical influence of thermal loading and glaciation on the stability and safety of a hypothetical repository. The Aespoe Hard Rock Laboratory test site was used as a target site for regional and local geology, in situ stress data and material properties. The study treated the rock mass as an assembly of discrete blocks defined by a number of major faults and fracture zones. Two computational models with 15 and 23 major faults and fracture zones were constructed and studied. Thermal loading due to waste emplacement and mechanical loading from a hypothetical glaciation/deglaciation cycle was applied in order to examine the global behaviour of the rock mass under such loading conditions. The problem was treated as a three-dimensional one, simulated by using the three-d distinct element method code 3DEC. From the numerical results, it was found that a maximum temperature of 48 deg C would be reached 200 years after the emplacement of the waste canisters. The average increase of maximum principal stress due to thermal loading is 9.5 MPa horizontally and 20.2 MPa vertically due to glaciation. The maximum shear displacement induced by thermal loading is 25 mm and 81.9 mm by glaciation. 15 refs

  8. Characterization and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The third Aespoe International Seminar was organised by SKB to assess the state of the art in characterisation and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Site characterisation and evaluation are important elements for determining the site suitability and long-term safety of a geological repository for radioactive waste disposal. Characterisation work also provides vital information for the design of the underground facility and the engineered barrier system that will contain the waste. The aim of the seminar was to provide a comprehensive assessment of the current know-how on this topic based on world-wide experience from more than 20 years of characterisation and evaluation work. The seminar, which was held at the Aespoe Hard Rock Laboratory was attended by 72 scientists from 10 different countries. The program was divided into four sessions of which two were run in parallel. A total of 38 oral and 5 poster presentations were given at the seminar. The presentations gave a comprehensive summary of recently completed and current work on site characterisation, modelling and application in performance assessments. The results presented at the seminar generally show that significant progress has been made in this field during the last decade. New characterisation techniques have become available, strategies for site investigations have developed further, and model concepts and codes have reached new levels of refinement. Data obtained from site characterisation have also successfully been applied in several site specific performance assessments. The seminar clearly showed that there is a solid scientific basis for assessing the suitability of sites for actual repositories based on currently available site characterisation technology and modelling capabilities. Separate abstracts have been prepared for 38 of the presentations

  9. Characterization and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Proceedings

    International Nuclear Information System (INIS)

    The third Aespoe International Seminar was organised by SKB to assess the state of the art in characterisation and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Site characterisation and evaluation are important elements for determining the site suitability and long-term safety of a geological repository for radioactive waste disposal. Characterisation work also provides vital information for the design of the underground facility and the engineered barrier system that will contain the waste. The aim of the seminar was to provide a comprehensive assessment of the current know-how on this topic based on world-wide experience from more than 20 years of characterisation and evaluation work. The seminar, which was held at the Aespoe Hard Rock Laboratory was attended by 72 scientists from 10 different countries. The program was divided into four sessions of which two were run in parallel. A total of 38 oral and 5 poster presentations were given at the seminar. The presentations gave a comprehensive summary of recently completed and current work on site characterisation, modelling and application in performance assessments. The results presented at the seminar generally show that significant progress has been made in this field during the last decade. New characterisation techniques have become available, strategies for site investigations have developed further, and model concepts and codes have reached new levels of refinement. Data obtained from site characterisation have also successfully been applied in several site specific performance assessments. The seminar clearly showed that there is a solid scientific basis for assessing the suitability of sites for actual repositories based on currently available site characterisation technology and modelling capabilities. Separate abstracts have been prepared for 38 of the presentations

  10. A new method to improve operating performance for underground hard rock mining - with new scheduling, controlling and forecastingtechniques

    OpenAIRE

    Song, Zhen

    2015-01-01

    In underground mining, there are missing links among mine planning, mining machines and mineral processing. They have significantly affected the overall performance of the entire mining process. There have been quite few studies aiming to improve the mining process of underground mines. In underground mines, mobile mining equipment is mostly scheduled instinctively, without theoretical support for these decisions. Furthermore, in case of unexpected events, it is hard for miners to rapidly fin...

  11. Utilizing partial least square and support vector machine for TBM penetration rate prediction in hard rock conditions

    Institute of Scientific and Technical Information of China (English)

    高栗; 李夕兵

    2015-01-01

    Rate of penetration (ROP) of a tunnel boring machine (TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accuracy of prediction models employing partial least squares (PLS) regression and support vector machine (SVM) regression technique for modeling the penetration rate of TBM. To develop the proposed models, the database that is composed of intact rock properties including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), and peak slope index (PSI), and also rock mass properties including distance between planes of weakness (DPW) and the alpha angle (α) are input as dependent variables and the measured ROP is chosen as an independent variable. Two hundred sets of data are collected from Queens Water Tunnel and Karaj−Tehran water transfer tunnel TBM project. The accuracy of the prediction models is measured by the coefficient of determination (R2) and root mean squares error (RMSE) between predicted and observed yield employing 10-fold cross-validation schemes. The R2 and RMSE of prediction are 0.8183 and 0.1807 for SVMR method, and 0.9999 and 0.0011 for PLS method, respectively. Comparison between the values of statistical parameters reveals the superiority of the PLSR model over SVMR one.

  12. Rock stress orientation measurements using induced thermal spalling in slim boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Hakami, Eva [Geosigma AB, Uppsala (Sweden)

    2011-05-15

    In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

  13. A CUSP CATASTROPHE, PRECURSORS PATTERN ANDEVOLUTION PROCESS OF ROCKBUST OF COAL PILLARUNDER A HARD ROCK SUBJECT TO ELASTIC SUPPORT

    Institute of Scientific and Technical Information of China (English)

    徐曾和; 徐小荷

    1996-01-01

    The rockburst of the coal pillar under a thick hard roof stratum is modelled as the instability failure problem of coal pillars under strata subject to elastic support. The instability mechanism of rockburst is studied by applying cusp catastrophic theory. The effects of the stiffness ratio of the system and loads imposed on the system on the rockburst are explicated.The factors affecting rockbursts are discussed. Based on them, the "evolution process, the forewarning regularity and forewarning sings of rockbursts are studied. It is indicated that the subsidence velocity of roof stratum, which increases quickly and tends to infinity, is the forewarning measurable signs of the rockbursts of coal pillar.

  14. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses may

  15. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Sanden, Torbjoern; Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jansson, Mats; Eriksen, Trygve E.; Svaerdstroem, Kjell (KTH Royal Inst. of Technology, Stockholm (Sweden)); Rosborg, Bo (Studsvik AB, Nykoeping (Sweden); Rosborg Consulting, Nykoeping (Sweden)); Muurinen, Arto (VTT, Espoo (Finland))

    2011-02-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses

  16. Assessment of groundwater potential based on aquifer properties of hard rock terrain in the Chittar-Uppodai watershed, Tamil Nadu, India

    Science.gov (United States)

    Kumar, T. Jeyavel Raja; Balasubramanian, A.; Kumar, R. S.; Dushiyanthan, C.; Thiruneelakandan, B.; Suresh, R.; Karthikeyan, K.; Davidraju, D.

    2014-07-01

    Aquifer performance was tested in 24 locations to assess the groundwater potential of the hard rock terrain in the Chittar-Uppodai watershed of the Tambaraparani River basin. Geologically, the area consists of biotite gneiss, charnockite, and quartzite. The aquifer characteristics, such as transmissivity (T), the storage coefficient, specific capacity, optimum yield, and the recovery rate were calculated. The drawdown transmissivity was determined using Jacob's straight-line method, while the recovery transmissivity was determined by the Theis method. The drawdown transmissivity was low in the western areas, particularly at Kadayanallur, and was higher in the other areas. The recovery transmissivity was high in the western area, and, with the exception of Gangaikondan, was low at other locations. The assessment indicates that there is groundwater potential in the western part of the study area because of favorable results for recovery drawdown, aquifer thickness, and specific capacity.

  17. Study of regional temperature and thermohydrological effects of an underground repository for nuclear wastes in hard rock

    International Nuclear Information System (INIS)

    Heat released by the radioactive decay of nuclear wastes in an underground repository causes a long-term thermal disturbance in the surrounding rock mass. The nature of this disturbance for a planar repository 3000 m in diameter at a depth of 500 m below surface is investigated for various waste forms. The effects of changes in the density and viscosity of groundwater caused by the temperature changes on the flow through a simple model of a vertical fracture connected to a horizontal fracture in a rock mass are evaluated. It is concluded that different waste forms and time periods before burial have significant effects on the thermal disturbance and that buoyant groundwater flow is a function of both the vertical and horizontal fracture transmissivities, as well as the changes in temperature. Loaded initially with a power density of 10 W/m2 of spent fuel assemblies 10 years after discharge from a reactor, the maximum increase in temperature of the repository in granite is about 500C and the epicentral thermal gradient about 700C/km. 30 figures, 4 tables

  18. Evaluation of regional fracture properties for groundwater development using hydrolithostructural domain approach in variably fractured hard rocks of Purulia district, West Bengal, India

    Indian Academy of Sciences (India)

    Tapas Acharya; Rajesh Prasad; S Chakrabarti

    2014-04-01

    Estimation of geohydrologic properties of fractured aquifers in hard crystalline and/or metamorphosed country rocks is a challenge due to the complex nature of secondary porosity that is caused by differential fracturing. Hydrologic potentiality of such aquifers may be assessed if the geological controls governing the spatial distribution of these fracture systems are computed using a software-based model. As an exemplar, the Precambrian metamorphics exposed in and around the Balarampur town of Purulia district, West Bengal (India) were studied to find out the spatial pattern and consistency of such fracture systems. Surfer and Statistica softwares were used to characterize these rock masses in terms of hydrological, structural and lithological domains. The technique is based on the use of hydraulically significant fracture properties to generate representative modal and coefficient of variance () of fracture datasets of each domain. The is interpreted to obtain the spatial variability of hydraulically significant fracture properties that, in turn, define and identify the corresponding hydrolithostructural domains. The groundwater flow estimated from such a technique is verified with the routine hydrological studies to validate the procedure. It is suggested that the hydrolithostructural domain approach is a useful alternative for evaluation of fracture properties and aquifer potentiality, and development of a regional groundwater model thereof.

  19. Contamination of fluoride in groundwater and its effect on human health: a case study in hard rock aquifers of Siddipet, Telangana State, India

    Science.gov (United States)

    Narsimha, A.; Sudarshan, V.

    2016-06-01

    Hydrogeochemical investigation has been carried out in the granitic terrain of Siddipet area, Medak district, Telangana State, India with an aim to understand the distribution of fluoride in the groundwater and to understand the relationship of fluoride with other major ions, and also to identify the high fluoride-bearing groundwater zones. 104 groundwater samples were analyzed in the study area for fluoride and other major ions like calcium, magnesium, chloride, carbonate, bicarbonate, sodium, potassium, sulfate, and nitrate in addition to pH and electrical conductivity. The studies revealed that the concentration of fluoride in groundwater is ranging from 0.2 to 2.2 mg L-1 with a mean of 1.1 mg L-1. Nearly 22 % of groundwater has more than the permissible limit of fluoride (1.5 mg L-1), which is responsible for the endemic dental fluorosis in the area concerned. Geochemical classification of groundwater shows that Na-HCO3, Ca-Cl, and Ca-HCO3-Na are the dominant hydrochemical facies. Gibbs diagram shows rock-water interaction dominance and evaporation dominance, which are responsible for the change in the quality of water in the hard rock aquifer of the study area. The groundwater in villages and its environs are affected by fluoride contamination, and consequently majority of the population living in these villages suffer from dental fluorosis. Hence, they are advised to consume drinking water which has less than 1.5 mg L-1 fluoride to avoid further fluorosis risks.

  20. Establishment of earth tides effect on water level fluctuations in an unconfined hard rock aquifer using spectral analysis

    CERN Document Server

    Maréchal, Jean-Christophe; Ahmed, Shakeel; Lachassagne, Patrick

    2010-01-01

    Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthetic earth tides as well as groundwater withdrawal time series in the surrounding. It was found that these fluctuations have considerably high correlation with earth tides whereas groundwater pumping does not show any significant correlation with water table fluctuations. It is concluded that earth tides cause the fluctuation in the water table. These fluctuations were hitherto unobserved during manual observations made over larger time intervals. It indicates that the unconfined aquifer is characterised by a low porosity.

  1. Use of the {sup 14}C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J.; Kirkkomaeki, T. [Saanio and Riekkola Oy, Helsinki (Finland); Siitari-Kauppi, M. [University of Helsinki (Finland). Lab. of Radiochemistry; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J. [University of Jyvaeskylae (Finland). Dept. of Physics

    1999-04-01

    Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the {sup 14}C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the {sup 14}C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The {sup 14}C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.) 23 refs.

  2. Use of the 14C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    International Nuclear Information System (INIS)

    Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the 14C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the 14C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The 14C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.)

  3. Real Time Grouting Control Method. Development and application using Aespoe HRL data

    International Nuclear Information System (INIS)

    The spread of grout is governed by a number of complex relations. The desired results, such as grout penetration and sealing of fractures, cannot be directly measured during the grouting process. This means that the issue of how or when the injection of grout should be stopped cannot be answered by simple rules of thumb. This is also the background to the great variety of empirical rules used in the grouting sector worldwide. The research during recent years has given a better understanding of the water-bearing structures of the rock mass as well as analytical solutions. In this report the methodology has been further studied and a method for design and control of rock grouting has been proposed. The concept of what we call the 'Real Time Grouting Control Method' is to calculate the grout penetration and control grouting in real time by applying the development of the theories for grout spread. Our intention is to combine our method with a computerized logging tool to acquire an active tool in order to be able to govern the grout spread in real time during the grouting operation. The objectives of this report are: to further develop the theory concerning the relationship between grout penetration and grouting time to describe the real course of grouting, to establish the concept of 'Real Time Grouting Control Method' for design and control for rock grouting based on the developed theory, and to verify the concept by using the field data from the grouting experiment at the 450 m level in the Aespoe HRL. In this report, the approximations and analysis of dimensionality have been checked and further developments of the theory with respect to varying grouting pressure, time-dependent grout properties, changing grout mixes, and changing the flow dimension of the fracture have been carried out. The concept of 'Real Time Grouting Control Method' has been described in order to calculate the grout penetration and to control grouting in real time by applying developed

  4. A physical basis for Ms-yield scaling in hard rock and implications for late-time damage of the source medium

    Science.gov (United States)

    Patton, Howard J.

    2016-04-01

    Surface wave magnitude Ms for a compilation of 72 nuclear tests detonated in hard rock media for which yields and burial depths have been reported in the literature is shown to scale with yield W as a + b × log[W], where a = 2.50 ± 0.08 and b = 0.80 ± 0.05. While the exponent b is consistent with an Ms scaling model for fully coupled, normal containment-depth explosions, the intercept a is offset 0.45 magnitude units lower than the model. The cause of offset is important to understand in terms of the explosion source. Hard rock explosions conducted in extensional and compressional stress regimes show similar offsets, an indication that the tectonic setting in which an explosion occurs plays no role causing the offset. The scaling model accounts for the effects of source medium material properties on the generation of 20-s period Rayleigh wave amplitudes. Aided by thorough characterizations of the explosion and tectonic release sources, an extensive analysis of the 26 October 1963 Shoal nuclear test detonated in granite 27 miles southeast of Fallon NV shows that the offset is consistent with the predictions of a material damage source model related to nonlinear stress wave interactions with the free surface. This source emits Rayleigh waves with polarity opposite to waves emitted by the explosion. The Shoal results were extended to analyze surface waves from the 15 February 1962 Hardhat nuclear test, the 14 September 1988 Soviet Joint Verification Experiment, and the anomalous 18 August 1979 northeast Balapan explosion which exhibits opposite polarity, azimuth-independent source component U1 compared to an explosion. Modeling these tests shows that Rayleigh wave amplitudes generated by the damage source are nearly as large as or larger than amplitudes from the explosion. As such, destructive interference can be drastic, introducing metastable conditions due to the sensitivity of reduced amplitudes to Rayleigh wave initial phase angles of the explosion and damage

  5. A physical basis for Ms-yield scaling in hard rock and implications for late-time damage of the source medium

    Science.gov (United States)

    Patton, Howard J.

    2016-07-01

    Surface wave magnitude Ms for a compilation of 72 nuclear tests detonated in hard rock media for which yields and burial depths have been reported in the literature is shown to scale with yield W as a + b × log[W], where a = 2.50 ± 0.08 and b = 0.80 ± 0.05. While the exponent b is consistent with an Ms scaling model for fully coupled, normal containment-depth explosions, the intercept a is offset 0.45 magnitude units lower than the model. The cause of offset is important to understand in terms of the explosion source. Hard rock explosions conducted in extensional and compressional stress regimes show similar offsets, an indication that the tectonic setting in which an explosion occurs plays no role causing the offset. The scaling model accounts for the effects of source medium material properties on the generation of 20-s period Rayleigh wave amplitudes. Aided by thorough characterizations of the explosion and tectonic release sources, an extensive analysis of the 1963 October 26 Shoal nuclear test detonated in granite 27 miles southeast of Fallon NV shows that the offset is consistent with the predictions of a material damage source model related to non-linear stress wave interactions with the free surface. This source emits Rayleigh waves with polarity opposite to waves emitted by the explosion. The Shoal results were extended to analyse surface waves from the 1962 February 15 Hardhat nuclear test, the 1988 September 14 Soviet Joint Verification Experiment, and the anomalous 1979 August 18 northeast Balapan explosion which exhibits opposite polarity, azimuth-independent source component U1 compared to an explosion. Modelling these tests shows that Rayleigh wave amplitudes generated by the damage source are nearly as large as or larger than amplitudes from the explosion. As such, destructive interference can be drastic, introducing metastable conditions due to the sensitivity of reduced amplitudes to Rayleigh wave initial phase angles of the explosion and

  6. Exploitation of high-yields in hard-rock aquifers: downscaling methodology combining GIS and multicriteria analysis to delineate field prospecting zones.

    Science.gov (United States)

    Lachassagne, P; Wyns, R; Bérard, P; Bruel, T; Chéry, L; Coutand, T; Desprats, J F; Le Strat, P

    2001-01-01

    Based on research work in the Truyère River catchment of the Massif Central (Lozère Department, France), a methodology has been developed for delineating favorable prospecting zones of a few square kilometers within basement areas of several hundred, if not thousand, square kilometers for the purpose of sitting high-yield water wells. The methodology adopts a functional approach to hard-rock aquifers using a conceptual model of the aquifer structure and of the functioning of the main aquifer compartments: the alterites (weathered and decayed rock), the underlying weathered-fissured zone, and the fractured bedrock. It involves an economically feasible method of mapping the thickness and spatial distribution of the alterites and the weathered-fissured zone, on which the long-term exploitation of the water resource chiefly depends. This method is used for the first time in hydrogeology. The potential ground water resources were mapped by GIS multicriteria analysis using parameters characterizing the structure and functioning of the aquifer, i.e., lithology and hydrogeological properties of the substratum, nature and thickness of the alterites and weathered-fissured zone, depth of the water table, slope, fracture networks and present-day tectonic stresses, and forecasted ground water quality. The methodology involves a coherent process of downscaling that, through applying methods that are increasingly precise but also increasingly costly, enables the selection of sites with diminishing surface areas as the work advances. The resulting documents are used for ground water exploration, although they can also be applied to the broader domain of land-use management. PMID:11447857

  7. Interests of hydrogeological observatories for characterizing heterogeneous groundwater systems: the example of the Ploemeur hard-rock aquifer (French Brittany)

    Science.gov (United States)

    Bour, O.; Le Borgne, T.; Aquilina, L.; Labasque, T.; Lavenant, N.; Boudin, F.; Leray, S.; De Dreuzy, J.; Longuevergne, L.; Hochreutener, R.; Davy, P.

    2012-12-01

    Heterogeneous aquifers are often poorly constrained by the available data. There is a strong need of characterizing at multiple space and time scales heterogeneous groundwater systems to improve model predictions. Here, we present results from the site of Ploemeur (French Brittany) that belongs to the network of hydrogeological sites H+, and where complementarity approaches have been developed for almost fifteen years. This outstandingly heterogeneous crystalline rock aquifer is used for water supply at a rate of about 10^6 m3 per year since 1991. The geology of the area is relatively complex and involves two main structures: a highly fractured contact zone between the Ploemeur's granite and the overlying micaschists, and a steeply dipping fault striking North 20°. The contact zone in itself consists of alternating deformed granitic sheets and enclaves of micaschists, pegmatite and aplite dykes, and locally mylonites and pegmatite-bearing breccias that are often associated with major borehole inflows. At the site scale - typically a square kilometer - and at relatively shallow depth (100 to 150 m), the connectivity of the main flow paths and the hydraulic properties are relatively well constrained and quantified thanks to cross-borehole flowmeter tests and traditional pumping tests. However, such data are relatively limited in explaining the functioning of this confined groundwater system at the regional scale. Groundwater chemistry and groundwater dating permit to go further to identify distinct reservoirs and in particular a relatively deep groundwater component whose age is older than 50 years. Groundwater temperature measurements demonstrate the role of the pumping that influences greatly the spatial distribution of groundwater temperature and quality. Moreover, it suggests that the main water supply comes from a depth of at least 300 meters. This implies relatively deep groundwater circulation that can be achieved only thanks to major permeable fault zone. At

  8. SITE-94. Development of a geological and a structural model of Aespoe, southeastern Sweden

    International Nuclear Information System (INIS)

    The objective of the present study is to construct three-dimensional geological and structural models to be used within the SKI SITE-94 project as a base for modelling hydrogeological, hydrochemical, and rock mechanical bedrock conditions, mass transport and layout of a hypothetical repository. The basic input data in the SITE-94 geological and structural models are restricted to geological and structural readings and geophysical measurements made prior to building the Hard Rock Laboratory. 114 refs, 82 figs, 28 tabs

  9. Groundwater potentiality mapping of hard-rock terrain in arid regions using geospatial modelling: example from Wadi Feiran basin, South Sinai, Egypt

    Science.gov (United States)

    Arnous, Mohamed O.

    2016-04-01

    Identifying a good site for groundwater exploitation in hard-rock terrains is a challenging task. In Sinai, Egypt, groundwater is the only source of water for local inhabitants. Interpretation of satellite data for delineation of lithological units and weathered zones, and for mapping of lineament density and their trends, provides a valuable aid for the location of groundwater promising areas. Complex deformational histories of the wide range of lithological formations add to the difficulty. Groundwater prospect mapping is a systematic approach that considers the major controlling factors which influence the aquifer and quality of groundwater. The presented study aims to delineate, identify, model and map groundwater potential zones in arid South Sinai using remote sensing data and a geographic information system (GIS) to prepare various hydromorphogeological thematic maps such as maps of slope, drainage density, lithology, landforms, structural lineaments, rainfall intensity and plan curvature. The controlling-factor thematic maps are each allocated a fixed score and weight, computed by using a linear equation approach. Furthermore, each weighted thematic map is statistically computed to yield a groundwater potential zone map of the study area. The groundwater potential zones thus obtained were divided into five categories (very poor, poor, moderate, good and very good) and were validated using the relation between the zone and the spatial distribution of productive wells and of previous geophysical investigations from a literature review. The results show the groundwater potential zones in the study area, and create awareness for better planning and management of groundwater resources.

  10. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 1. Executive summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Potomac Electric Power Company (PEPCO) and Acres American Incorporated (AAI) have carried out a preliminary design study of water-compensated Compressed Air Energy Storage (CAES) and Underground Pumped Hydroelectric (UPH) plants for siting in geological conditions suitable for hard rock excavations. The work was carried out over a period of three years and was sponsored by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI) and PEPCO. The study was divided into five primary tasks as follows: establishment of design criteria and analysis of impact on power system; selection of site and establishment of site characteristics; formulation of design approaches; assessment of environmental and safety aspects; and preparation of preliminary design of plant. The salient aspects considered and the conclusions reached during the consideration of the five primary tasks for both CAES and UPH are presented in this Executive Summary, which forms Volume 1 of the series of reports prepared during the study. The investigations and analyses carried out, together with the results and conclusions reached, are described in detail in Volumes 2 through 13 and ten appendices.

  11. Lithological and hydrochemical controls on distribution and speciation of uranium in groundwaters of hard-rock granitic aquifers of Madurai District, Tamil Nadu (India).

    Science.gov (United States)

    Thivya, C; Chidambaram, S; Keesari, Tirumalesh; Prasanna, M V; Thilagavathi, R; Adithya, V S; Singaraja, C

    2016-04-01

    Uranium is a radioactive element normally present in hexavalent form as U(VI) in solution and elevated levels in drinking water cause health hazards. Representative groundwater samples were collected from different litho-units in this region and were analyzed for total U and major and minor ions. Results indicate that the highest U concentration (113 µg l(-1)) was found in granitic terrains of this region and about 10 % of the samples exceed the permissible limit for drinking water. Among different species of U in aqueous media, carbonate complexes [UO2(CO3) 2 (2-) ] are found to be dominant. Groundwater with higher U has higher pCO2 values, indicating weathering by bicarbonate ions resulting in preferential mobilization of U in groundwater. The major minerals uraninite and coffinite were found to be supersaturated and are likely to control the distribution of U in the study area. Nature of U in groundwater, the effects of lithology on hydrochemistry and factors controlling its distribution in hard rock aquifers of Madurai district are highlighted in this paper. PMID:26104429

  12. A Novel Mogi Type True Triaxial Testing Apparatus and Its Use to Obtain Complete Stress-Strain Curves of Hard Rocks

    Science.gov (United States)

    Feng, Xia-Ting; Zhang, Xiwei; Kong, R.; Wang, G.

    2016-05-01

    A true triaxial apparatus (TTA) was designed and fabricated at Northeastern University, Shenyang, China, by modifying the original Mogi type testing apparatus to emulate three-dimensional stress paths in deep mining and tunneling excavations. Such an apparatus can be used to investigate deformation and brittle failure behaviors of hard rocks as well as the cause of rockbursts. The novel TTA can capture the post-peak behavior of a 50 × 50 × 100 mm3 specimen. Technical improvements such as a considerable increase of the stiffness of the loading frames were implemented to deal with difficulties in TTA testing. The accuracy of the volume change measurement was improved and a combined pneumatic and hydraulic technique was applied to create a "floating" vertical loading frame. The end friction effect and the loading gap effect were evaluated using a series of tests. Repeatability tests, brittle failure tests in a loading stress path and an unloading stress path (unloading of σ 3) were carried out on granite specimens to verify the performance of the TTA. The test results show that the apparatus achieves its original design goal.

  13. DRILLING OF HARD ROCKS USING PULSED POWER TECHNOLOGY%利用脉冲功率技术对岩石进行钻孔

    Institute of Scientific and Technical Information of China (English)

    白峰; 邱毓昌

    2001-01-01

    本文介绍一种脉冲功率技术在工业中的最新应用—在坚硬的岩石上钻孔。这种方法不同于以往对岩石进行加工的方法,其基本原理是由于液体和固体介质的动态击穿场强不同,当一高能量短脉冲施加于液体-固体界面时,固体介质表面比液体更容易发生击穿。这种方法单脉冲最大刻蚀量可以达到183cm3。%This article introduces the latest application of pulsed powertechnology in industry—drilling of hard rocks. It is different from the previous process method, the principle of which is based on the difference of dynamic breakdown-field strength in liquid and solid material. When a liquid-solid interface is applied with high-power short-pulse, the surface of solid material is broken down more easily than liquid. The maximal cutting amount can reach 183 cm3 by the new method.

  14. Evaluation of stationary and non-stationary geostatistical models for inferring hydraulic conductivity values at Aespoe

    International Nuclear Information System (INIS)

    This report describes the comparison of stationary and non-stationary geostatistical models for the purpose of inferring block-scale hydraulic conductivity values from packer tests at Aespoe. The comparison between models is made through the evaluation of cross-validation statistics for three experimental designs. The first experiment consisted of a 'Delete-1' test previously used at Finnsjoen. The second test consisted of 'Delete-10%' and the third test was a 'Delete-50%' test. Preliminary data analysis showed that the 3 m and 30 m packer test data can be treated as a sample from a single population for the purposes of geostatistical analyses. Analysis of the 3 m data does not indicate that there are any systematic statistical changes with depth, rock type, fracture zone vs non-fracture zone or other mappable factor. Directional variograms are ambiguous to interpret due to the clustered nature of the data, but do not show any obvious anisotropy that should be accounted for in geostatistical analysis. Stationary analysis suggested that there exists a sizeable spatially uncorrelated component ('Nugget Effect') in the 3 m data, on the order of 60% of the observed variance for the various models fitted. Four different nested models were automatically fit to the data. Results for all models in terms of cross-validation statistics were very similar for the first set of validation tests. Non-stationary analysis established that both the order of drift and the order of the intrinsic random functions is low. This study also suggests that conventional cross-validation studies and automatic variogram fitting are not necessarily evaluating how well a model will infer block scale hydraulic conductivity values. 20 refs, 20 figs, 14 tabs

  15. Theoretical study of rock mass investigation efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Johan G.; Outters, Nils [Golder Associates, Uppsala (Sweden)

    2002-05-01

    The study concerns a mathematical modelling of a fractured rock mass and its investigations by use of theoretical boreholes and rock surfaces, with the purpose of analysing the efficiency (precision) of such investigations and determine the amount of investigations necessary to obtain reliable estimations of the structural-geological parameters of the studied rock mass. The study is not about estimating suitable sample sizes to be used in site investigations.The purpose of the study is to analyse the amount of information necessary for deriving estimates of the geological parameters studied, within defined confidence intervals and confidence level In other words, how the confidence in models of the rock mass (considering a selected number of parameters) will change with amount of information collected form boreholes and surfaces. The study is limited to a selected number of geometrical structural-geological parameters: Fracture orientation: mean direction and dispersion (Fisher Kappa and SRI). Different measures of fracture density (P10, P21 and P32). Fracture trace-length and strike distributions as seen on horizontal windows. A numerical Discrete Fracture Network (DFN) was used for representation of a fractured rock mass. The DFN-model was primarily based on the properties of an actual fracture network investigated at the Aespoe Hard Rock Laboratory. The rock mass studied (DFN-model) contained three different fracture sets with different orientations and fracture densities. The rock unit studied was statistically homogeneous. The study includes a limited sensitivity analysis of the properties of the DFN-model. The study is a theoretical and computer-based comparison between samples of fracture properties of a theoretical rock unit and the known true properties of the same unit. The samples are derived from numerically generated boreholes and surfaces that intersect the DFN-network. Two different boreholes are analysed; a vertical borehole and a borehole that is

  16. Theoretical study of rock mass investigation efficiency

    International Nuclear Information System (INIS)

    The study concerns a mathematical modelling of a fractured rock mass and its investigations by use of theoretical boreholes and rock surfaces, with the purpose of analysing the efficiency (precision) of such investigations and determine the amount of investigations necessary to obtain reliable estimations of the structural-geological parameters of the studied rock mass. The study is not about estimating suitable sample sizes to be used in site investigations.The purpose of the study is to analyse the amount of information necessary for deriving estimates of the geological parameters studied, within defined confidence intervals and confidence level In other words, how the confidence in models of the rock mass (considering a selected number of parameters) will change with amount of information collected form boreholes and surfaces. The study is limited to a selected number of geometrical structural-geological parameters: Fracture orientation: mean direction and dispersion (Fisher Kappa and SRI). Different measures of fracture density (P10, P21 and P32). Fracture trace-length and strike distributions as seen on horizontal windows. A numerical Discrete Fracture Network (DFN) was used for representation of a fractured rock mass. The DFN-model was primarily based on the properties of an actual fracture network investigated at the Aespoe Hard Rock Laboratory. The rock mass studied (DFN-model) contained three different fracture sets with different orientations and fracture densities. The rock unit studied was statistically homogeneous. The study includes a limited sensitivity analysis of the properties of the DFN-model. The study is a theoretical and computer-based comparison between samples of fracture properties of a theoretical rock unit and the known true properties of the same unit. The samples are derived from numerically generated boreholes and surfaces that intersect the DFN-network. Two different boreholes are analysed; a vertical borehole and a borehole that is

  17. Conceptual and analytical modeling of fracture zone aquifers in hard rock. Implications of pumping tests in the Pohjukansalo well field, east-central Finland

    International Nuclear Information System (INIS)

    the approximate cone of depression around pumping wells and, subsequently, the extent of protection areas. In many developing countries, knowledge of water level fluctuations is insufficient and long-term pumping tests are not economically feasible. Sustainable well yield must be estimated by extrapolating short-term tests. Fractional flow dimension models commonly simulate responses to pumping in hard rocks and, therefore, can improve the present groundwater management methods. Conductive fracture zones generally control the 3-dimensional flow paths in fractured rocks and, subsequently, affect the spatial variations of groundwater composition. Studies of groundwater quality should probably take into account to what extent the sampled bored well represents groundwater in the hydrogeologically favorable parts of the bedrock. (orig.)

  18. SITE-94. Near-field rock mechanical modelling for nuclear waste disposal

    International Nuclear Information System (INIS)

    Fractured rock masses in the vicinity of a tunnel and a deposition hole of a waste repository are studied with respect to its mechanical stability. The three-dimensional distinct element code (3DEC) is applied. Four loading events of the near-field rock masses are considered: repository excavation, swelling pressure of bentonite, thermal loading due to heat release, and glaciation. From a statistic model of the fracture distribution in the Aespoe bedrock, three fracture network realizations are applied to the 3DEC model. The sensitivity of different fracture distributions on the simulated results is evaluated. 400 canisters are assumed to be deposited in the repository. The stresses measured in borehole KAS02 at Aespoe are used as boundary stresses for this study. The mechanical properties of intact rock and rock fractures are taken from previous experimental results for granite and the thermo-mechanical properties are the same as those used by previous SKB studies. 11 refs

  19. Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Tasks 6A, 6B and 6B2

    International Nuclear Information System (INIS)

    This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization and performance assessment approaches to solute transport in fractured rock. The present report is concerned solely with Tasks 6b, 6b and 6b which relate to the transport of tracers on a 5-metre scale in Feature A at the TRUE-1 site. The task objectives, specifications and individual modelling team results are summarised and reviewed, and an evaluation of the overall exercise is presented. The report concludes with assessments of what has been learnt, the implications for the Task 6 objectives, and some possible future directions

  20. High spatial variability of nitrate in the hard rock aquifer of an irrigated catchment: Implications for water resource assessment and vulnerability

    Science.gov (United States)

    Buvaneshwari, Sriramulu; Riotte, Jean; Ruiz, Laurent; Sekhar, Muddu; Mohan Kumar, Mandalagiri S.; Sharma, Amit Kumar; Duprey, Jean Louis; Audry, Stephane; Praveen, Yerabham; Hemanth, Moger; Durand, Patrick; Braun, Jean Jacques

    2016-04-01

    groundwater gradient was high, NO3 concentrations were low to moderate, suggesting that significant lateral flow prevented NO3 enrichment; iii) Finally, low NO3 concentrations were also found in situations where gradient was small but groundwater was shallow and hence reserve was large: these zones are potentially vulnerable to intensification of pumping and fertilizer application. Subsequent decline in groundwater level would then lead to rapid degradation of groundwater quality. We propose that the groundwater level and gradient mapping could be used in hard rock aquifers to delineate zones affected or vulnerable to intensification of irrigated agriculture. Wells located in low gradient zones are suitable for assessing the impacts of local agricultural systems. To the contrary, wells located in zones with high gradient (well mixed) are more representative of the average groundwater quality of the catchment, and hence should be used in priority for regional mapping of groundwater quality.

  1. SITE-94. Discrete-feature modelling of the Aespoe Site: 3. Predictions of hydrogeological parameters for performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.E. [Golder Associates AB, Uppsala (Sweden)

    1996-12-01

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Predicted parameters for the near field include fracture spacing, fracture aperture, and Darcy velocity at each of forty canister deposition holes. Parameters for the far field include discharge location, Darcy velocity, effective longitudinal dispersion coefficient and head gradient, flow porosity, and flow wetted surface, for each canister source that discharges to the biosphere. Results are presented in the form of statistical summaries for a total of 42 calculation cases, which treat a set of 25 model variants in various combinations. The variants for the SITE-94 Reference Case model address conceptual and parametric uncertainty related to the site-scale hydrogeologic model and its properties, the fracture network within the repository, effective semi regional boundary conditions for the model, and the disturbed-rock zone around the repository tunnels and shafts. Two calculation cases simulate hydrologic conditions that are predicted to occur during future glacial episodes. 30 refs.

  2. SITE-94. Discrete-feature modelling of the Aespoe Site: 3. Predictions of hydrogeological parameters for performance assessment

    International Nuclear Information System (INIS)

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Predicted parameters for the near field include fracture spacing, fracture aperture, and Darcy velocity at each of forty canister deposition holes. Parameters for the far field include discharge location, Darcy velocity, effective longitudinal dispersion coefficient and head gradient, flow porosity, and flow wetted surface, for each canister source that discharges to the biosphere. Results are presented in the form of statistical summaries for a total of 42 calculation cases, which treat a set of 25 model variants in various combinations. The variants for the SITE-94 Reference Case model address conceptual and parametric uncertainty related to the site-scale hydrogeologic model and its properties, the fracture network within the repository, effective semi regional boundary conditions for the model, and the disturbed-rock zone around the repository tunnels and shafts. Two calculation cases simulate hydrologic conditions that are predicted to occur during future glacial episodes. 30 refs

  3. Development and application of groundwater flow meter in fractured rocks: Measurement of velocity and direction of groundwater flow in single well

    International Nuclear Information System (INIS)

    For the confirmation of safety for the geological disposal of radioactive wastes, it is very important to demonstrate the groundwater flow by in-situ investigation in the deep underground. We have developed a groundwater flow meter to measure simultaneously the velocity and direction of groundwater flow by means of detecting the electric potential difference between the groundwater to evaluate and the distilled water as a tracer in a single well. In this paper, we describe the outline of the groundwater flow meter system developed by CRIEPI and Taisei-Kiso-Sekkei Co. Ltd. and the evaluation methodology for observed data by using it in fractured rocks. Furthermore, applied results to in-situ tests at the Tounou mine of Japan Nuclear Fuel Cycle Development Institute (JNC) and the Aespoe Hard Rock Laboratory (HRL) of Swedish Nuclear Fuel and Waste Management Co. (SK) are described. Both sites are different type of fractured rock formations of granite. From these results, it was made clear that this flow meter system can be practically used to measure the groundwater flow direction and velocity as low as order of 1x10-3∼10-7 cm/sec. (author)

  4. Effects of glacial/post-glacial weathering compared with hydrothermal alteration - implications for matrix diffusion. Results from drillcore studies in porphyritic quartz monzodiorite from Aespoe SE Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Landstroem, Ove [Studsvik Eco and Safety AB, Nykoeping (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Eriksson, Gunda; Sandell, Yvonne [Studsvik Nuclear AB, Nykoeping (Sweden)

    2001-08-01

    The effects of hydrothermal + subsequent low temperature alteration and glacial/post-glacial weathering have been studied in two cores of quartz monzodiorite. One core (YA 1192) was drilled into the hydrothermally altered wall rock of a water-conducting fracture exposed at 170 m depth in the access tunnel to the Aespoe Hard Rock Laboratory. The other one (Bas 1) was drilled from an outcrop with a glacially polished surface, 1 km north of the YA 1192 site. Both drill cores were sectioned into mm-thick slices perpendicular to the core axis. The fracture filling of the YA 1192 core, the weathered surface of the BAS 1 core and the different slices were analysed for major and trace elements and isotopes of U and Th. The altered zone of the YA 1192 core extends to approx. 2.5 cm from the fracture surface. The alteration (mainly plagioclase {yields} albite + sericite + epidote) has resulted in a higher porosity and formation of sorbing secondary minerals (e.g. sericite), favouring matrix diffusion. Increased Br concentrations in the altered zone are indicative of saline water in pores and micro fractures i.e. the presence of a diffusion medium. 234U/238U activity ratios > 1 and increased Cs in the altered zone are then interpreted as diffusion of U and Cs from fracture groundwater and subsequent sorption. The U migration is geologically recent (< 1 Ma). The 2.5 cm altered zone (corresponding to the zone of active matrix diffusion) significantly exceeds the visible red staining zone (0.5 cm) caused by hematite/FeOOH micrograins, emphasizing the need of microscopy to identify zones of alteration. The conspicuous weathering at the BAS 1 site is confined to a narrow rim of the bedrock surface (approx. 0.2-0.5 cm thick). Mass balance calculations for this rim (based on immobility of K) indicate that mechanical erosion has dominated over chemical dissolution processes (is roughly 10 times greater). The chemical weathering has affected mainly plagioclase and chlorite resulting

  5. Effects of glacial/post-glacial weathering compared with hydrothermal alteration - implications for matrix diffusion. Results from drillcore studies in porphyritic quartz monzodiorite from Aespoe SE Sweden

    International Nuclear Information System (INIS)

    The effects of hydrothermal + subsequent low temperature alteration and glacial/post-glacial weathering have been studied in two cores of quartz monzodiorite. One core (YA 1192) was drilled into the hydrothermally altered wall rock of a water-conducting fracture exposed at 170 m depth in the access tunnel to the Aespoe Hard Rock Laboratory. The other one (Bas 1) was drilled from an outcrop with a glacially polished surface, 1 km north of the YA 1192 site. Both drill cores were sectioned into mm-thick slices perpendicular to the core axis. The fracture filling of the YA 1192 core, the weathered surface of the BAS 1 core and the different slices were analysed for major and trace elements and isotopes of U and Th. The altered zone of the YA 1192 core extends to approx. 2.5 cm from the fracture surface. The alteration (mainly plagioclase → albite + sericite + epidote) has resulted in a higher porosity and formation of sorbing secondary minerals (e.g. sericite), favouring matrix diffusion. Increased Br concentrations in the altered zone are indicative of saline water in pores and micro fractures i.e. the presence of a diffusion medium. 234U/238U activity ratios > 1 and increased Cs in the altered zone are then interpreted as diffusion of U and Cs from fracture groundwater and subsequent sorption. The U migration is geologically recent (< 1 Ma). The 2.5 cm altered zone (corresponding to the zone of active matrix diffusion) significantly exceeds the visible red staining zone (0.5 cm) caused by hematite/FeOOH micrograins, emphasizing the need of microscopy to identify zones of alteration. The conspicuous weathering at the BAS 1 site is confined to a narrow rim of the bedrock surface (approx. 0.2-0.5 cm thick). Mass balance calculations for this rim (based on immobility of K) indicate that mechanical erosion has dominated over chemical dissolution processes (is roughly 10 times greater). The chemical weathering has affected mainly plagioclase and chlorite resulting in

  6. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  7. Characterising and modelling the excavation damaged zone (EDZ) in crystalline rock in the context of radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, J.A.; Backstrom, A.; Rutqvist, J.; Jing, L.; Backers, T.; Chijimatsu, M.; Christiansson, R.; Feng, X.-T.; Kobayashi, A.; Koyama, T.; Lee, H.-S.; Neretnieks, I.; Pan, P.Z.; Rinne, M.; Shen, B.-T.

    2008-10-01

    This paper describes current knowledge about the nature of and potential for thermo-hydro-mechanical-chemical modelling of the Excavation Damaged Zone (EDZ) around the excavations for an underground radioactive waste repository. In the first part of the paper, the disturbances associated with excavation are explained, together with reviews of Workshops that have been held on the subject. In the second part of the paper, the results of a DECOVALEX research programme on modelling the EDZ are presented. Four research teams used four different models to simulate the complete stress-strain curve for Avro granite from the Swedish Aespoe Hard Rock Laboratory. Subsequent research extended the work to computer simulation of the evolution of the repository using a 'wall block model' and a 'near-field model'. This included assessing the evolution of stress, failure and permeability and time dependent effects during repository evolution. As discussed, all the computer models are well suited to sensitivity studies for evaluating the influence of their respective supporting parameters on the complete stress-strain curve for rock and for modelling the EDZ.

  8. Assuring Sustainable Economic Benefit for Farmers by Using Ground Water in Semi-Arid, Hard Rock Areas in India & the Role of UNESCO-IUGS-IGCP Project 523 “GROWNET”

    Directory of Open Access Journals (Sweden)

    Shrikant Daji Limaye

    2012-04-01

    Full Text Available Out of about 1.2 billion people in India, 68% people live on agriculture as their main occupation. Ground water is therefore an important resource which provides over 70% of rural drinking water supply and about 50% of water used for irrigation. Rains in Monsoon season from June to September, provide the main source of water but they last only for four months and the rest of the year is dry in most of the hard rock region. About 67% of India is occupied by hard rock terrain and about 30% of the hard rock area falls within semi-arid, drought-prone zone receiving less than 500 mm rainfall per year. In semi-arid, hard rock terrain in India and in many other low-income countries, the surface water resources are scarce and polluted. Ground water occurs in this area in the shallow weathered zone up to about 15 meters depth and in the deeper fractures and fissures up to about 100 m depth. Bore wells reaching up to 60 to 100 meters depth, installed with hand-pumps, are very common for providing safe drinking water supply to villages. This causes a positive improvement in the health of villagers and an economic advantage by reducing the number of working days lost due to illness. Agricultural production in these semi-arid areas is just marginal because the rain-fed crops suffer from the vagaries of Monsoon rains. The average farm-size per family of 5 persons is about 2 Ha. There are 3 to 5 drought years within a span of 10 years, which leave the dry-land farmer in perpetual poverty. In the past 3 years, over 4,200 farmers have committed suicide due to continued crop failures. Ground water, therefore, forms a very important and reliable resource which, if available in a farmer’s plot of land and if utilized prudently for irrigation by digging or drilling a well, could transform the farmers lifestyle. Even if the farmers are able to save one rainy season (Monsoon crop through protective irrigation from dug well, and if possible take winter and summer

  9. Palaeohydrological implications in the Baltic area and its relation to the groundwater at Aespoe, south-eastern Sweden - A literature study

    International Nuclear Information System (INIS)

    A literature study of different groundwaters in the circum Baltic region is presented in this work. The study is mainly focused on the isotopic signatures observed in different groundwaters in Sweden and Finland. Several saline groundwaters in the Baltic region at depth of 150 to 500m depth show stable (δD, δ13C, δ18O) and radiogenic (δ87Sr) isotope assembly which is suggestive of a marine origin. However, a discrepancy is sometimes observed between the stable as well as radiogenic isotopes of the intermediate groundwater, which suggest a mixture of fossil marine water and a post-glacial runoff of melt water. In order to explain this phenomenon, the initial setting in δ18O may have been depleted due to large input of high latitude marine water or cold melt waters. A solution to the contradiction between the strontium (δ87Sr) and stable isotope (δD, δ13C, δ18O) signatures of the groundwater and of the calcite fracture fillings at Aespoe and other places is attained, if it is assumed that the strontium in Baltic Sea water has undergone a significant decrease in δ87Sr since the last glaciation. A scenario can be constructed to suggest that the Baltic Sea during the initial stage of the Litorina sea (8000 to 5000 Y B.P.) contained strontium with much larger δ87Sr values. Another explanation for the positive δ87Sr values may be due to water/rock interaction between the groundwater and the abundant fracture clay minerals, which are observed at Aespoe. Typically most of the saline groundwaters occur both in Sweden and Finland below the highest marine shore line during the Holocene. Almost all inland groundwaters show a totally different pattern which is typically non marine, meteoric in origin. This study also summarises the stable isotope (δ13C,δ18O) geochemistry dependence of the important global and regional environmental changes which may have influenced of the palaeohydrology as well as groundwater formation and in the Baltic region and especially at

  10. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  11. Changes in rock damage parameters due to chemical effects of salt water

    International Nuclear Information System (INIS)

    To investigate the effect of the chemical degradation on the mechanical behavior, the rock samples preserved in the 10% salt water and distilled water for 90 days are subjected to the unconfined compression test. The rock samples were obtained from Aespoe HRL in Sweden. The damage parameters were identified from the unconfined compression tests for two types of rock samples. By investigating the change in the damage parameters of the chemically degraded rock, the effect of the chemical degradation was tried to infer. Moreover, the 3-D finite element simulation was carried out using the damage parameters. (author)

  12. Palaeohydrological implications in the Baltic area and its relation to the groundwater at Aespoe, south-eastern Sweden - A literature study

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, B. [Geokema AB, Lidingoe (Sweden)

    1995-03-01

    A literature study of different groundwaters in the circum Baltic region is presented in this work. The study is mainly focused on the isotopic signatures observed in different groundwaters in Sweden and Finland. Several saline groundwaters in the Baltic region at depth of 150 to 500m depth show stable ({delta}D, {delta}{sup 13}C, {delta}{sup 18}O) and radiogenic ({delta}{sup 87}Sr) isotope assembly which is suggestive of a marine origin. However, a discrepancy is sometimes observed between the stable as well as radiogenic isotopes of the intermediate groundwater, which suggest a mixture of fossil marine water and a post-glacial runoff of melt water. In order to explain this phenomenon, the initial setting in {delta}{sup 18}O may have been depleted due to large input of high latitude marine water or cold melt waters. A solution to the contradiction between the strontium ({delta}{sup 87}Sr) and stable isotope ({delta}D, {delta}{sup 13}C, {delta}{sup 18}O) signatures of the groundwater and of the calcite fracture fillings at Aespoe and other places is attained, if it is assumed that the strontium in Baltic Sea water has undergone a significant decrease in {delta}{sup 87}Sr since the last glaciation. A scenario can be constructed to suggest that the Baltic Sea during the initial stage of the Litorina sea (8000 to 5000 Y B.P.) contained strontium with much larger {delta}{sup 87}Sr values. Another explanation for the positive {delta}{sup 87}Sr values may be due to water/rock interaction between the groundwater and the abundant fracture clay minerals, which are observed at Aespoe. Typically most of the saline groundwaters occur both in Sweden and Finland below the highest marine shore line during the Holocene. Almost all inland groundwaters show a totally different pattern which is typically non marine, meteoric in origin. (Abstract Truncated)

  13. Challenges in planning and performing the retrieval of the prototype repository at Aespoe HRL- Project management's reflections and practical experiences from field work

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Since 2001 the Prototype Repository at Aespoe Hard Rock Laboratory has been carried out as a large-scale experimental installation of the KBS-3 Swedish/Finnish concept for final disposal of spent nuclear fuel. The overall objective of the trial 'Prototype Repository' is to test and demonstrate the integrated function of sub-components in a final repository under realistic full-scale conditions. Data from the experiment shall also be compared to results from modelling based on site conditions. Opening of the outer section for the Prototype Repository was recognized as substantial operation. No trial of this size has been made earlier with regard to removal of buffer and backfilling. Experience was available only from retrieval of the buffer in Canister Retrieval Test at Aespoe HRL where samples of the buffer were taken, down to the mid-height of the canister. It was expected that sampling of the buffer in the deposition holes of the Prototype Repository would be very difficult, especially deep down in the holes. No significant experience regarding the breaching of such a concrete plug or removing backfill was available. The lack of experience together with the size of the project made extensive planning essential before the opening and removal could begin. It was decided that SKB (Sweden) and Posiva Oy (Finland) should run the project in a co-operation, where SKB is responsible for managing the project. In addition, a wide international interest was observed and accordingly waste management organisations were invited by SKB and Posiva to be a party to the Retrieval of the Prototype Repository. Six individual project agreements were signed with Andra (France), NUMO (Japan), NDA (United Kingdom), NAGRA (Switzerland), BMWi (Germany) and NWMO (Canada). The planning of the Retrieval of the Prototype Repository (section II) started at the beginning of 2010. The planning phase was successful meaning that the breaching of

  14. Microbial O{sub 2} consumption in the Aespoe tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Kotelnikova, S.; Pedersen, Karsten [Goeteborg Univ. (Sweden). Dept. of Cell and Molecular Biology, Microbiology

    1998-04-01

    The report presents data on microbial O{sub 2} reduction activities by microorganisms obtained with different techniques: Winkler method, gas chromatography, most probable numbering, enrichment technique, inhibitor analysis and radiotracer measurements. The samples were collected from boreholes and open funnel ponds at Aespoe in 1996-1998. The evaluation of the microbial activities in open ponds predicts the future microbial activities after the O{sub 2} intrusion around the future repository. The metabolic potential of the microbial population inhabiting groundwater was evaluated on the basis of electron donors available and microbial 16S rRNA gene diversity. The contribution of different microbial groups to the O{sub 2} reduction was elucidated using specific inhibitors selectively affecting different microbial groups. Our experiments show that microbial O{sub 2} reduction occurs in deep groundwater. Carbon dioxide was produced concurrently with O{sub 2} reduction confirming the biogenic nature of the reduction. The populations developed O{sub 2} reduction rates and capacity depending on the initial concentration of dissolved O{sub 2} reduction. Rates of O{sub 2} reduction ranged from 0.32 to 4.5 {mu}M/day. Depending on temperature and the type of groundwater the approximate time needed for consumption of 500 {mu}M of dissolved O{sub 2} ranged from 0.31 to 3.99 years. After approximately a 2 weeks period the microbial population in vitro was able to consume O{sub 2} both at 30 deg C and 60 deg C. At 16 deg C no delay in O{sub 2} consumption was observed. Our results demonstrated that methanotrophs survive in deep groundwater and that they were induced by O{sub 2}. Some bacteria use Hg or CH{sub 4} as electron donor instead of organic matter, which means that microbial O{sub 2} reduction will occur also in deep groundwaters where the availability of organic carbon is limited. Specific CH{sub 4} oxidation rates ranged between 3.00 and 220 nM CH{sub 4} per litre per

  15. Microbial O2 consumption in the Aespoe tunnel

    International Nuclear Information System (INIS)

    The report presents data on microbial O2 reduction activities by microorganisms obtained with different techniques: Winkler method, gas chromatography, most probable numbering, enrichment technique, inhibitor analysis and radiotracer measurements. The samples were collected from boreholes and open funnel ponds at Aespoe in 1996-1998. The evaluation of the microbial activities in open ponds predicts the future microbial activities after the O2 intrusion around the future repository. The metabolic potential of the microbial population inhabiting groundwater was evaluated on the basis of electron donors available and microbial 16S rRNA gene diversity. The contribution of different microbial groups to the O2 reduction was elucidated using specific inhibitors selectively affecting different microbial groups. Our experiments show that microbial O2 reduction occurs in deep groundwater. Carbon dioxide was produced concurrently with O2 reduction confirming the biogenic nature of the reduction. The populations developed O2 reduction rates and capacity depending on the initial concentration of dissolved O2 reduction. Rates of O2 reduction ranged from 0.32 to 4.5 μM/day. Depending on temperature and the type of groundwater the approximate time needed for consumption of 500 μM of dissolved O2 ranged from 0.31 to 3.99 years. After approximately a 2 weeks period the microbial population in vitro was able to consume O2 both at 30 deg C and 60 deg C. At 16 deg C no delay in O2 consumption was observed. Our results demonstrated that methanotrophs survive in deep groundwater and that they were induced by O2. Some bacteria use Hg or CH4 as electron donor instead of organic matter, which means that microbial O2 reduction will occur also in deep groundwaters where the availability of organic carbon is limited. Specific CH4 oxidation rates ranged between 3.00 and 220 nM CH4 per litre per day. Comparison of the total O2 reducing activities by gas chromatography and radiotracer tests

  16. Estimation of effective block conductivities based on discrete network analyses using data from the Aespoe site

    International Nuclear Information System (INIS)

    Numerical continuum codes may be used for assessing the role of regional groundwater flow in far-field safety analyses of a nuclear waste repository at depth. The focus of this project is to develop and evaluate one method based on Discrete Fracture Network (DFN) models to estimate block-scale permeability values for continuum codes. Data from the Aespoe HRL and surrounding area are used. 57 refs, 76 figs, 15 tabs

  17. Mineralogical and chemical characteristics of the bentonite in the A2 test parcel of the LOT field experiments at Aespoe HRL (Sweden))

    International Nuclear Information System (INIS)

    The Long Term Test of Buffer Material (LOT) project at the Aespoe Hard Rock Laboratory (Sweden)), is a series of medium-scale field experiments focused on validating models and hypotheses concerning long term processes in the bentonite buffer of a repository for high-level radioactive waste. The test parcels emplaced in crystalline bedrock consist of blocks of compacted MX80 bentonite embedding a Cu-tube equipped with a heater to simulate the heat generation from radionuclide decay. The A2 test parcel had been subjected to elevated temperature (up to 130 deg. C) and hydration by a Na-Ca-Cl type groundwater for almost 6. years when it was retrieved to be analysed. The analyses included determinations of chemical composition, cation exchange capacity (CEC), exchangeable cations and mineralogy. Both the bulk bentonite and dialysed, homo-ionic Na-clay (<2 μm and <0.2 μm fractions) were analysed when relevant. Sulphate was redistributed in the heated part of the buffer under the thermal and hydration gradients that prevailed during the test period. Anhydrite accumulated in the warmer parts, whereas gypsum was dissolved in the peripheral parts of the buffer where water was supplied. Carbonate dissolution increased with temperature in the warmest parts, whereas chloride behaved conservatively in all blocks. Cu was incorporated in the bentonite matrix at the surface of the Cu-tube indicating some corrosion, which may be explained by reactions in an early stage of the test when trapped oxygen existed in the system. Along with the dissolution/precipitation reactions the pore water composition changed, which resulted in replacement of exchangeable sodium by calcium and magnesium in the warmest zone. Also Mg in the clay (<2 μm and <0.2 μm fractions) displays a clear gradient with peak values at the heater. Because several of the alternative sinks for Mg were eliminated in the sample preparation prior to the chemical analysis (purified clay fractions, removal of carbonates

  18. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In the fields of power conversion devices and broadcasting/communication amplifiers, high power, high frequency and low losses are desirable. Further, for electronic elements in aerospace/aeronautical/geothermal surveys, etc., heat resistance to 500degC is required. Devices which respond to such hard specifications are called hard electronic devices. However, with Si which is at the core of the present electronics, the specifications cannot fully be fulfilled because of the restrictions arising from physical values. Accordingly, taking up new device materials/structures necessary to construct hard electronics, technologies to develop these to a level of IC were examined and studied. They are a technology to make devices/IC of new semiconductors such as SiC, diamond, etc. which can handle higher temperature, higher power and higher frequency than Si and also is possible of reducing losses, a technology to make devices of hard semiconducter materials such as a vacuum microelectronics technology using ultra-micro/high-luminance electronic emitter using negative electron affinity which diamond, etc. have, a technology to make devices of oxides which have various electric properties, etc. 321 refs., 194 figs., 8 tabs.

  19. Sealing of 300 mm boreholes KXTT3 and KXTT4 at Aespoe HRL. Report of Subproject 3 of Borehole sealing Project

    International Nuclear Information System (INIS)

    Sealing of two moderately dipping 300 mm diameter holes that had been bored from a niche adjacent to the ramp in the Aespoe URL in conjunction with earlier geohydrological investigations (TRUE Project, Winberg et al. 2000) was successfully completed in early 2010. The work was preceded by a pilot test on the ground surface for investigating if a simple version of sealing by pressing down clay pellets into clay mud is feasible. The borehole was simulated by a steel tube that was filled with smectite mud in which a cage filled with clay pellets was moved down. The experience from this experiment was that the mud used was somewhat too stiff and that strong vibration significantly reduced its viscosity but not sufficiently much. The predicted average density at water saturation was 1,780 kg/m3 (dry density 1,240 kg/m3). The finally selected sealing method comprised casting of concrete plugs where the inflow of water was significant (up to 30 l/min), and to install precompacted blocks of smectite-rich clay where the rock was 'dry'. The finally matured clay plugs will have a density of around 2,000 kg/m3 (dry density 1,580 kg/m3) and a hydraulic conductivity of less than E-12 m/s, which is estimated to be at least one order of magnitude lower than the bulk conductivity of the surrounding rock mass (Pusch 2008). This provides excellent sealing of all parts of the holes deeper than about 1-2 m below the tunnel floor. Groundwater flow in the rock around the clay plugs can cause some minor erosion but this effect is deemed negligible considering the coagulating effect on released clay particles by the brackish Aespoe water. Inspection of the closed upper borehole ends showed accumulation of some very dilute mineral suspension after a few days. A careful analysis of the mineral content showed that it did not contain smectite particles, hence certifying that erosion of the clay plugs in the holes had not taken place. The particles were concluded to represent fracture minerals

  20. Properties of waterproof sprayed concrete tunnel linings: A study of EVA-based sprayed membranes for waterproofing of rail and road tunnels in hard rock and cold climate

    OpenAIRE

    Holter, Karl Gunnar

    2015-01-01

    Investigate the long term effects of exposure of the SCL lining to higher ground water pressure, particularly the exposure of the membrane to pressurized water at cracks Investigate the effects of slow deformations and slow thermal fluctuations in order to complement the finding from short-term accelerated testing the mechanical performance parameters Investigate the longitudinal thermal profile of selected tunnels, combined with thermal monitoring in the lining and rock mass in...

  1. Hard rock drilling: from conventional technologies to the potential use of laser; Perfuracao em rochas duras: das tecnologias convencionais ate o potencial uso do laser

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, Renato; Lomba, Rosana Fatima Teixieira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Perez, Maria Angelica Acosta; Valente, Luiz Carlos Guedes; Braga, Arthur Martins Barbosa [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2012-07-01

    One of the biggest challenges in the drilling of the carbonate rocks of the Pre-salt is to overcome the low penetration rates that have been obtained in the drilling of the reservoir rock in the vertical and directional wells. To overcome this challenge, a great effort is being developed in several lines of research, both in developing new concepts in drill bits and in the selection of a drilling system that together with appropriate type of bit provide an expected improvement in performance. To achieve these results, procedures are being prioritized and drilling systems with lower vibration levels are being used, since this phenomenon of vibration reduces the performance of penetration rate also affecting the lifetime of the equipment and consequently causes a reduction in reliability of all system and raises the cost per meter of drilling. Thus, new drill bit technology and new drilling systems are under development and, among these technologies we can distinguish those that promote improvements in conventional technologies and innovative technologies frankly which uses new mechanisms to cut or weaken the rock. This paper presents an overview of the conventional technology of drilling systems and drill bits, and provides information about the researches that have been developed with the use of innovative technologies which is presented as highly promising, among these innovative technologies, laser drilling and the drilling itself assisted by laser. In this process the laser beam has the main function to weaken the rock improving the rate of penetration. This paper presents a summary of studies and analyzes which are underway to investigate the potential of laser technology, also presents some results of laboratory tests already carried out. The drilling fluid in which the laser will have to pass through in the future applications is analyzed on the approach of their physicochemical properties. Thus, a better understanding of the interaction with the drilling

  2. Hard rock excavation at the CSM/OCRD test site using crater theory and current United States controlled smooth wall blasting practices, June 1982

    International Nuclear Information System (INIS)

    This report is the fourth in a series describing experiments conducted by the Colorado School of Mines for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. The report describes the application of tunnel design procedures based upon crater theory and current United States controlled smooth wall blasting practices for the excavation of the CSM/OCRD test room in the Colorado School of Mines, Experimental Mine (Edgar Mine) in Idaho Springs, Colorado. Ten blast rounds were used to excavate the test room. The first seven rounds were designed with Swedish Techniques, and described in the third report in this series, and the design of rounds eight through ten used crater theory. Crater theory is described in this document along with its application to the CSM/OCRD Room excavation. Calculation for spacing, burden, number and type of holes, explosives placement, and overall powder factor are discussed. A series of single charge cratering test shots, designed to evaluate some of the input data for the blast designs, are discussed. The input data include: Strain Energy Factor E, a dimensionless factor which varies according to the explosive and rock type; Critical Depth, N, the charge depth at which the explosive begins to fracture rock at the free face; Optimum Depth Ratio Δ0, which is a ratio between Optimum Charge Depth, d0, and Critical Charge Depth, d/sub c/; and charge Weight, W. A non-linear least squared regression method to best fit the general bell-shape curve of the crater results is discussed. Both scaled weight and scaled volume criteria are reported in the analysis of results. 10 references, 17 figures, 16 tables

  3. Chemistry and origin of deep ground water in crystalline rocks

    International Nuclear Information System (INIS)

    This report discusses the interactions between water and crystalline rocks and its consequences for the chemical composition of the water. It also treats how flows of different types of water are modified by the rock, and the possible consequences for the ground water near a nuclear waste repository. The focus of the work is the changes in composition that ground water gets at deep levels in the rock. Data from Finnsjoen and Aespoe in Sweden show higher salinity in deep rock, which has been interpreted as a result of marine inflow of water during glaciation. Data from other, deeper boreholes in Finland, Canada, Russia, England and Sweden show that the increasing salinity is a rule and very high at great depths, higher than marine water can produce. Therefore, the deep waters from Finnsjoen and Aespoe are probably very old, and the high salinity a result from geological processes. Differing cation and isotopic composition than seawater also indicate geologic water. Differing theories on the origin of the ground water should be regarded in the safety analysis for a repository. 36 refs, 3 figs, 1 tab

  4. Groundwater modelling of Aespoe using the ECLIPSE program

    International Nuclear Information System (INIS)

    The pre-investigations indicated that the dominant rocks ranged in composition from true granite to dioritic or gabbroic rocks. In conjunction with these investigations at the area, a number of indications were obtained of high transmissive fracture zones. To be able to understand the fracture zone NE-1 as well as possible, a number of hydraulic tests were performed, for example a tracer test. The program ECLIPSE 100 is one of the standard programs in the oil industry which is used to simulate oil fields. ECLIPSE 100 is a multi-facility simulator and it can be used to simulate 1, 2 and 3 phase systems, one option is oil, two phase options are oil/gas, oil/water or gas/water, and the third option is oil/gas/water. Good results were obtained from the simulator match of the tracer concentration versus time to the measured values from the tracer test of the fracture zone NE-1. The simulation was less successful in modelling the draw-down of water in the wells. We were also unable to reach a balance situation for the water pressure prior to injecting the tracer in order to accommodate several weeks of leakage into the tunnel prior to the tracer test. As a main conclusion, we found the results of the simulation to be satisfactory and we believe that further work should be done to adapt the program completely for groundwater simulation. 19 refs, 10 tabs, 13 figs

  5. Immobilization of uranium and neptunium by microorganisms in subsurface crystalline rock environments

    Energy Technology Data Exchange (ETDEWEB)

    Krawczyk-Baersch, Evelyn; Schmeide, Katja; Bok, Frank [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, P.O. Box 51 01 19, D-01314 Dresden (Germany); Pedersen, Karsten [Department of Civil and Environmental Engineering, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2014-07-01

    In crystalline rock, the dominant transport medium for radionuclides is groundwater flowing through subsurface fractures. Since groundwater is containing microorganisms, fracture surfaces support biological growth of microbial communities, the so-called bio-films. The microbial diversity of these bio-films depends on the microbial consortia and the chemical composition of the fracture water. Subsurface bio-films have a significant effect on the adsorption capacity of host rock formations by forming a barrier between the rock surface and the groundwater. They can significantly affect subsurface biogeochemical interactions, leading to the immobilization and adsorption of radionuclides. Microbial studies were performed to evaluate the relevance of microbial processes for the immobilization of radionuclides in a deep crystalline repository for high-level radioactive waste. Studies were performed in Olkiluoto, in the rock characterization facility ONKALO in Finland, and in the Aespoe Hard Rock Laboratory (HRL) in Sweden. Massive 5-10-mm thick bio-films were observed in both sites attached to tunnel walls where groundwater was seeping from bedrock fractures. In experiments the effect of uranium on bio-films was studied on site in the ONKALO tunnel by adding UO{sub 2}(ClO{sub 4}){sub 2} with a final U-concentration of 1.0x10{sup -5} M to the fracture water in a self-constructed flow cell by using detached bio-film samples. bio-film specimens collected for transmission electron microscopy studies indicated that uranium in the bio-film was immobilized intracellularly in microorganisms as needle-shaped uranyl phosphate minerals, similar to meta-Autunite (Ca[UO{sub 2}]{sub 2}[PO{sub 4}]{sub 2}.10-12H{sub 2}O). In contrast, thermodynamic calculation of the theoretical predominant fields of uranium species and time-resolved laser fluorescence spectroscopy showed that the formation of aqueous uranium carbonate species Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3} and Mg{sub 2}UO{sub 2

  6. Immobilization of uranium and neptunium by microorganisms in subsurface crystalline rock environments

    International Nuclear Information System (INIS)

    In crystalline rock, the dominant transport medium for radionuclides is groundwater flowing through subsurface fractures. Since groundwater is containing microorganisms, fracture surfaces support biological growth of microbial communities, the so-called bio-films. The microbial diversity of these bio-films depends on the microbial consortia and the chemical composition of the fracture water. Subsurface bio-films have a significant effect on the adsorption capacity of host rock formations by forming a barrier between the rock surface and the groundwater. They can significantly affect subsurface biogeochemical interactions, leading to the immobilization and adsorption of radionuclides. Microbial studies were performed to evaluate the relevance of microbial processes for the immobilization of radionuclides in a deep crystalline repository for high-level radioactive waste. Studies were performed in Olkiluoto, in the rock characterization facility ONKALO in Finland, and in the Aespoe Hard Rock Laboratory (HRL) in Sweden. Massive 5-10-mm thick bio-films were observed in both sites attached to tunnel walls where groundwater was seeping from bedrock fractures. In experiments the effect of uranium on bio-films was studied on site in the ONKALO tunnel by adding UO2(ClO4)2 with a final U-concentration of 1.0x10-5 M to the fracture water in a self-constructed flow cell by using detached bio-film samples. bio-film specimens collected for transmission electron microscopy studies indicated that uranium in the bio-film was immobilized intracellularly in microorganisms as needle-shaped uranyl phosphate minerals, similar to meta-Autunite (Ca[UO2]2[PO4]2.10-12H2O). In contrast, thermodynamic calculation of the theoretical predominant fields of uranium species and time-resolved laser fluorescence spectroscopy showed that the formation of aqueous uranium carbonate species Ca2UO2(CO3)3 and Mg2UO2(CO3)3 was predicted due to the high concentration of carbonate in the groundwater. At the

  7. Evaluation of modelling of the TRUE-1 radially converging tests with sorbing tracers. The Aespoe task force on modelling of groundwater flow and transport of solutes. Tasks 4E and 4F

    Energy Technology Data Exchange (ETDEWEB)

    Elert, M.; Svensson, Haakan [Kemakta Konsult AB, Stockholm (Sweden)

    2001-05-01

    The Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. In this report, the modelling work performed within Tasks 4E and 4F is evaluated, which comprised predictive modelling of the tracer tests (STT-1, STT-1b and STT-2) performed within the TRUE-1 project using sorbing and non-sorbing tracers. The tests were made between packed off boreholes penetrating a water-conducting geological feature with a simple structure (Feature A). Nine modelling teams representing eight organisations have performed predictive modelling of the tracer tests using different modelling approaches and models. The modelling groups were initially given data from the site characterisation, data from preliminary tracer tests performed with non-sorbing tracers and data on the experimental set-up of the sorbing tracer tests. Based on this information, model predictions were made of drawdown, tracer mass recovery and tracer breakthrough. For the predictions of the STT-1b and STT-2 tests results from previous tracer tests with sorbing tracer were also available. The predictions of the sorbing tracer breakthrough in the initial tracer test (STT-1) generally underestimated the breakthrough time, suggesting the need to include additional processes and evaluate the application of the laboratory data. As a result of model calibration and modification the predictions were considerably improved for the latter tracer tests (STT-1b and STT-2). Task 4E and 4F have proved to be very valuable in increasing the understanding of non-sorbing tracer transport in fractured rock. There is a general consensus on the major processes responsible for

  8. Evaluation of modelling of the TRUE-1 radially converging tests with sorbing tracers. The Aespoe task force on modelling of groundwater flow and transport of solutes. Tasks 4E and 4F

    International Nuclear Information System (INIS)

    The Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. In this report, the modelling work performed within Tasks 4E and 4F is evaluated, which comprised predictive modelling of the tracer tests (STT-1, STT-1b and STT-2) performed within the TRUE-1 project using sorbing and non-sorbing tracers. The tests were made between packed off boreholes penetrating a water-conducting geological feature with a simple structure (Feature A). Nine modelling teams representing eight organisations have performed predictive modelling of the tracer tests using different modelling approaches and models. The modelling groups were initially given data from the site characterisation, data from preliminary tracer tests performed with non-sorbing tracers and data on the experimental set-up of the sorbing tracer tests. Based on this information, model predictions were made of drawdown, tracer mass recovery and tracer breakthrough. For the predictions of the STT-1b and STT-2 tests results from previous tracer tests with sorbing tracer were also available. The predictions of the sorbing tracer breakthrough in the initial tracer test (STT-1) generally underestimated the breakthrough time, suggesting the need to include additional processes and evaluate the application of the laboratory data. As a result of model calibration and modification the predictions were considerably improved for the latter tracer tests (STT-1b and STT-2). Task 4E and 4F have proved to be very valuable in increasing the understanding of non-sorbing tracer transport in fractured rock. There is a general consensus on the major processes responsible for

  9. 上软下硬岩质地层浅埋大跨隧道松动压力计算%Calculation method of relaxation pressure of shallow large span tunnel in up-soft/low-hard rock stratum

    Institute of Scientific and Technical Information of China (English)

    王志伟; 乔春生; 宋超业

    2014-01-01

    In accordance with the problems of existing methods for surrounding rock pressure of shallow large-span tunnel in up-soft/low-hard rock stratum, by using DEM (distinct element method) and orthogonal array testing method, the law and sensibilities of the failure mechanism of loose zone and the thickness of overlying weak rock stratum and the joint occurrence influencing on shape and scope of the loose zone are analyzed. In sequence, the sensibilities of factors are as follows in the magnitude order: thickness of overlying weak rock stratum, tunnel depth, angle and distance of continuous inclined joint, distance of horizontal joints in weak rock stratum. Through comparative analysis two failure modes of arch collapse and caving collapse are obtained;the boundary curves are analyzed and fit with linear and non-linear models by using the software ORIGIN, the test results show their boundary curves are power function curve and parabola curve. In accordance with caving collapse loose zone, new formulae for the length of earth surface crack and the soil strip width above the vault are formulated by using the liner least squares method. The errors of the empirical formulae are analyzed. According to the stress transfer principle, a differential trapezoid geotechnical strip is chosen as research object, the formula of surrounding rock pressure of loose zone which considering the joint occurrence and thickness of overlying weak rock stratum is deduced. Case studies show that the results of proposed method are smaller than the results of the existing representative methods.%针对现有方法在上软下硬岩质地层中浅埋大跨隧道松动压力计算方面存在的问题,通过离散元数值模拟和正交试验,分析了围岩的松动破坏机制、风化层厚度和岩体中节理分布状态对隧道松动区形状和范围的影响规律及敏感性。结果表明:影响松动区的主要因素依次为风化层厚度、隧道埋深、贯通倾斜节理的

  10. A numerical simulation of the origin and composition of the groundwater below Aespoe

    International Nuclear Information System (INIS)

    An attempt is made to calculate the origin (in the time and space) of the waters found below Aespoe. It is assumed that the present water composition is due to the conditions prevailing after the last glaciation (initial conditions) and the hydrological events after this time (resulting in transient boundary conditions). The total time span simulated is from 10,000 years BP to 5 000 years AP. The different water types are tracked by solving an advection/diffusion equation for each of the identified water types. This novel technique is called the 'fluid population method' and is a simple and straightforward computational technique. Results from the simulation include the distribution of different water types in space and time and some detailed results for the conditions at 450 metres below Aespoe (water composition transport time to ground level). The main conclusion from the study is that the simulation model gives plausible results. However, the uncertainties about the basic conceptual model and the boundary conditions do not presently make a direct comparison with field data meaningful

  11. Uncertainty in rock properties: Implications for analysis of radionuclide migration in heterogeneous bedrock

    International Nuclear Information System (INIS)

    A basic rationale for the current study is that site investigations in connection with the planning of the final repository for high radioactive waste will provide only fragmentary (discrete) information of the bedrock properties. Since the bedrock displays generally a significant heterogeneity in most properties of relevance to radionuclide migration, there will be uncertainties about the barrier effect provided by the bedrock towards accidental leakage of radionuclides from the repository. This paper shows how the heterogeneity in the bedrock properties has two fundamentally different implications for an analysis of radionuclide transport. First, the actual variation of bedrock properties causes migrating nuclides to encounter a certain (known) distribution of properties along their transport path. The associated effect does not depend on the spatial correlation of properties (auto-covariance), but does depend on the variance and cross-correlation between the properties. A second effect is due to the uncertainty about the statistical representativity of properties along an individual transport path, which is related to the discrete measuring technique. This effect can, generally, be considered to be the main effect of the heterogeneity of the bedrock on analysis of solute transport. By analysis of an ensemble of equally probable realisations of the transport along an individual path we were able to express the expected values of the mean and variance of the residence time PDF for radionuclides travelling in a single fracture. The 'uncertainty effect' is significant if a certain sum of H-terms is much larger than unity. Based on geostatistical information for the Swedish granitic bedrock, the effect of uncertainty of bedrock properties on the transport of radionuclides can be important for fractures thinner than about 0.1 mm. The geostatistical information was obtained through sampling drill-cores at the Aespoe Hard Rock Laboratory and performing a large number of

  12. SITE-94. Discrete-feature modelling of the Aespoe site: 4. Source data and detailed analysis procedures

    International Nuclear Information System (INIS)

    Specific procedures and source data are described for the construction and application of discrete-feature hydrological models for the vicinity of Aespoe. Documentation is given for all major phases of the work, including: Statistical analyses to develop and validate discrete-fracture network models, Preliminary evaluation, construction, and calibration of the site-scale model based on the SITE-94 structural model of Aespoe, Simulation of multiple realizations of the integrated model, and variations, to predict groundwater flow, and Evaluation of near-field and far-field parameters for performance assessment calculations. Procedures are documented in terms of the computer batch files and executable scripts that were used to perform the main steps in these analyses, to provide for traceability of results that are used in the SITE-94 performance assessment calculations. 43 refs

  13. SITE-94. Discrete-feature modelling of the Aespoe site: 4. Source data and detailed analysis procedures

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.E. [Golder Associates AB, Uppsala (Sweden)

    1996-12-01

    Specific procedures and source data are described for the construction and application of discrete-feature hydrological models for the vicinity of Aespoe. Documentation is given for all major phases of the work, including: Statistical analyses to develop and validate discrete-fracture network models, Preliminary evaluation, construction, and calibration of the site-scale model based on the SITE-94 structural model of Aespoe, Simulation of multiple realizations of the integrated model, and variations, to predict groundwater flow, and Evaluation of near-field and far-field parameters for performance assessment calculations. Procedures are documented in terms of the computer batch files and executable scripts that were used to perform the main steps in these analyses, to provide for traceability of results that are used in the SITE-94 performance assessment calculations. 43 refs.

  14. Hard coatings

    OpenAIRE

    Dan, J.; Boving, H.; Hintermann, H.

    1993-01-01

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many process...

  15. Regional groundwater flow in hard rocks

    International Nuclear Information System (INIS)

    The territory of continental Portugal has a geologic history marked by the Hercynian orogeny, and to the north of this country the Hercynian large-scale tectonic structures are typically represented by long and deep NW–SE trending ductile shear zones and NNE–SSW trending fragile faults. These structures are elements of mineral and thermal water circuits that discharge as springs in more than one hundred locations. The purpose of this study is to investigate if these structures are also used by shallower non-mineral groundwater, integrated in a large-scale regional flow system. Using an original combination of water balance and recession flow models, it was possible to calculate catchment turnover times based solely on groundwater discharge rates and recession flow parameters. These times were then used to classify a group of 46 watersheds as closed or open basins, and among the later class to identify source and sink basins, based on innovative interpretations of relationships between turnover time and catchment area. By definition, source basins transfer groundwater to sink basins and altogether form a regional flow system. Using a Geographic Information System, it could be demonstrated the spatial association of open basins to the Hercynian ductile and fragile tectonic structures and hence to classify the basins as discharge cells of a regional flow system. Most of the studied watersheds are sub-basins of the Douro River basin, one of the largest regional catchments in the Iberian Peninsula, being located in its mouth area. Because the largest part of open basins is sink, which by definition tends to dominate in the mouth area of regional catchments, it is proposed as an extension of the studied area conceptual boundaries towards the Douro River basin headwaters, where the corresponding sources could be searched for. - Highlights: • Introduce a method to distinguish open from closed groundwater basins • Identify structural elements of a regional flow system in northern Portugal • Propose the Douro River basin as the regional watershed • Combine topographic, hydrologic and geologic data in a GIS

  16. Regional groundwater flow in hard rocks

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Fernando A.L., E-mail: fpacheco@utad.pt

    2015-02-15

    The territory of continental Portugal has a geologic history marked by the Hercynian orogeny, and to the north of this country the Hercynian large-scale tectonic structures are typically represented by long and deep NW–SE trending ductile shear zones and NNE–SSW trending fragile faults. These structures are elements of mineral and thermal water circuits that discharge as springs in more than one hundred locations. The purpose of this study is to investigate if these structures are also used by shallower non-mineral groundwater, integrated in a large-scale regional flow system. Using an original combination of water balance and recession flow models, it was possible to calculate catchment turnover times based solely on groundwater discharge rates and recession flow parameters. These times were then used to classify a group of 46 watersheds as closed or open basins, and among the later class to identify source and sink basins, based on innovative interpretations of relationships between turnover time and catchment area. By definition, source basins transfer groundwater to sink basins and altogether form a regional flow system. Using a Geographic Information System, it could be demonstrated the spatial association of open basins to the Hercynian ductile and fragile tectonic structures and hence to classify the basins as discharge cells of a regional flow system. Most of the studied watersheds are sub-basins of the Douro River basin, one of the largest regional catchments in the Iberian Peninsula, being located in its mouth area. Because the largest part of open basins is sink, which by definition tends to dominate in the mouth area of regional catchments, it is proposed as an extension of the studied area conceptual boundaries towards the Douro River basin headwaters, where the corresponding sources could be searched for. - Highlights: • Introduce a method to distinguish open from closed groundwater basins • Identify structural elements of a regional flow system in northern Portugal • Propose the Douro River basin as the regional watershed • Combine topographic, hydrologic and geologic data in a GIS.

  17. SITE-94. Discrete-feature modelling of the Aespoe site: 2. Development of the integrated site-scale model

    International Nuclear Information System (INIS)

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Hydrologic properties of the large-scale structures are initially estimated from cross-hole hydrologic test data, and automatically calibrated by numerical simulation of network flow, and comparison with undisturbed heads and observed drawdown in selected cross-hole tests. The calibrated model is combined with a separately derived fracture network model, to yield the integrated model. This model is partly validated by simulation of transient responses to a long-term pumping test and a convergent tracer test, based on the LPT2 experiment at Aespoe. The integrated model predicts that discharge from the SITE-94 repository is predominantly via fracture zones along the eastern shore of Aespoe. Similar discharge loci are produced by numerous model variants that explore uncertainty with regard to effective semi regional boundary conditions, hydrologic properties of the site-scale structures, and alternative structural/hydrological interpretations. 32 refs

  18. Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

    Science.gov (United States)

    Jaunat, J.; Dupuy, A.; Huneau, F.; Celle-Jeanton, H.; Le Coustumer, P.

    2016-04-01

    A numerical groundwater model of the weathered crystalline aquifer of Ursuya (a major water source for the north-western Pyrenees region, south-western France) has been computed based on monitoring of hydrological, hydrodynamic and meteorological parameters over 3 years. The equivalent porous media model was used to simulate groundwater flow in the different layers of the weathered profile: from surface to depth, the weathered layer (5 · 10-8 ≤ K ≤ 5 · 10-7 m s-1), the transition layer (7 · 10-8 ≤ K ≤ 1 · 10-5 m s-1, the highest values being along major discontinuities), two fissured layers (3.5 · 10-8 ≤ K ≤ 5 · 10-4 m s-1, depending on weathering profile conditions and on the existence of active fractures), and the hard-rock basement simulated with a negligible hydraulic conductivity (K = 1 10 -9 ). Hydrodynamic properties of these five calculation layers demonstrate both the impact of the weathering degree and of the discontinuities on the groundwater flow. The great agreement between simulated and observed hydraulic conditions allowed for validation of the methodology and its proposed use for application on analogous aquifers. With the aim of long-term management of this strategic aquifer, the model was then used to evaluate the impact of climate change on the groundwater resource. The simulations performed according to the most pessimistic climatic scenario until 2050 show a low sensitivity of the aquifer. The decreasing trend of the natural discharge is estimated at about -360 m3 y-1 for recharge decreasing at about -5.6 mm y-1 (0.8 % of annual recharge).

  19. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    OpenAIRE

    Fereshteh Ahmadi

    2009-01-01

    The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  20. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    Directory of Open Access Journals (Sweden)

    Fereshteh Ahmadi

    2009-07-01

    Full Text Available The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  1. Evaluation of modelling of the TRUE-1 radially converging and dipole tests with conservative tracers. The Aespoe task force on modelling of groundwater flow and transport of solutes. Tasks 4C and 4D

    International Nuclear Information System (INIS)

    The 'Aespoe task force on modelling of groundwater flow and transport of solutes' is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. In this report, the modelling work performed within Tasks 4C and 4D is evaluated, which comprised predictive modelling of the radially converging tracer tests and dipole tracer tests performed within the TRUE-1 tests using non-sorbing tracers. The tests were performed between packed off boreholes penetrating a water-conducting geological feature with a simple structure (Feature A). These tests are to a great extent preparatory steps for the subsequent tests with sorbing radioactive tracers. In Tasks 4E and 4F of the Aespoe Modelling Task Force predictive modelling of the sorbing tracer tests is performed. Eight modelling teams representing seven organisations have performed predictive modelling using different modelling approaches and models. The modelling groups were initially given data from the site characterisation and data on the experimental set-up of the tracer tests. Based on this information model predictions were performed of drawdown, tracer mass recovery and tracer breakthrough. The performed predictions shows that the concept of Feature A as a singular well-connected feature with limited connectivity to its surroundings is quite adequate for predictions of drawdown in boreholes and conservative tracer breakthrough. Reasonable estimates were obtained using relatively simple models. However, more elaborate models with calibration or conditioning of transmissivities and transport apertures are required for more accurate predictions. The general flow and transport processes are well understood, but the methodology to derive the

  2. Soft rocks in Argentina

    Institute of Scientific and Technical Information of China (English)

    Giambastiani; Mauricio

    2014-01-01

    Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification (consolidation, cemen-tation, new formed minerals), chemical sedimentary rocks and metamorphic rocks formed by minerals with Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the latter. They also include any type of rock that suffered alteration processes (hydrothermal or weathering). In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties (UCS, deformability) to physical index (porosity, density, etc.) has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text (Chihuído dam, N. Kirchner dam, J. Cepernic Dam, etc.) and others such as International Tunnel in the Province of Mendoza (Corredor Bioceánico), which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improv-ing techniques will result in benefits to the better understanding of the geomechanics of weak rocks.

  3. The Aespoe redox investigations in block scale. Project summary and implications for repository performance assessment

    International Nuclear Information System (INIS)

    During construction and operation of a deep repository for high level waste, the groundwater environment will be open to oxidizing surface conditions and surface water inflow. Construction of the access tunnel to the Hard Rock Laboratory intersected a vertical fracture zone at a depth of 70 m. Changes in the groundwater chemistry were then monitored for a period of three years. Mass balances for conservative and reactive natural tracers provided a basis for a site model of the fracture zone. Groundwater dilution was the dominant process affecting the geochemistry of the site. There was associated Na-Ca ion-exchange. There is evidence for extensive lateral flow between recharge areas and the discharge point in the access tunnel. There was a significant transport of young organic carbon from the surface to the discharge borehole during recharge. Proposed microbial processes during lateral flow include anaerobic respiration coupled to reduction of iron hydroxide, methanogenesis, precipitation of calcite and secondary ferrous minerals. There is strong evidence to rule out sulfate reduction. Sulfate increased dramatically, possibly by desorption from fracture minerals. Fracture performance is affected by the extensive groundwater dilution and by the microbial processes that occur. Dilution affects aqueous speciation, radionuclide solubility and sorption, and the stability and mobility of colloids. Aerobic respiration provides an effective sink for oxygen. Maintaining anoxia favors low solubility for Tc, Np, Pu and U. Reductive dissolution of iron hydroxide will release sorbed radionuclides, while formation of biogenic Fe(II) minerals can provide an effective reducing migration barrier to radionuclides and to future intrusion of oxygen from the surface. 26 refs, 13 figs, 10 tabs

  4. The Aespoe redox investigations in block scale. Project summary and implications for repository performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Banwart, S. [ed.] [Bradford Univ. (United Kingdom). Dept. of Civil Engineering

    1995-11-01

    During construction and operation of a deep repository for high level waste, the groundwater environment will be open to oxidizing surface conditions and surface water inflow. Construction of the access tunnel to the Hard Rock Laboratory intersected a vertical fracture zone at a depth of 70 m. Changes in the groundwater chemistry were then monitored for a period of three years. Mass balances for conservative and reactive natural tracers provided a basis for a site model of the fracture zone. Groundwater dilution was the dominant process affecting the geochemistry of the site. There was associated Na-Ca ion-exchange. There is evidence for extensive lateral flow between recharge areas and the discharge point in the access tunnel. There was a significant transport of young organic carbon from the surface to the discharge borehole during recharge. Proposed microbial processes during lateral flow include anaerobic respiration coupled to reduction of iron hydroxide, methanogenesis, precipitation of calcite and secondary ferrous minerals. There is strong evidence to rule out sulfate reduction. Sulfate increased dramatically, possibly by desorption from fracture minerals. Fracture performance is affected by the extensive groundwater dilution and by the microbial processes that occur. Dilution affects aqueous speciation, radionuclide solubility and sorption, and the stability and mobility of colloids. Aerobic respiration provides an effective sink for oxygen. Maintaining anoxia favors low solubility for Tc, Np, Pu and U. Reductive dissolution of iron hydroxide will release sorbed radionuclides, while formation of biogenic Fe(II) minerals can provide an effective reducing migration barrier to radionuclides and to future intrusion of oxygen from the surface. 26 refs, 13 figs, 10 tabs.

  5. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

    International Nuclear Information System (INIS)

    This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved by the

  6. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

    Energy Technology Data Exchange (ETDEWEB)

    Roeshoff, Kennert; Lanaro, Flavio [Berg Bygg Konsult AB, Stockholm (Sweden); Lanru Jing [Royal Inst. of Techn., Stockholm (Sweden). Div. of Engineering Geology

    2002-05-01

    This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved

  7. Standard hardness conversion tables for metals relationship among brinell hardness, vickers hardness, rockwell hardness, superficial hardness, knoop hardness, and scleroscope hardness

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 Conversion Table 1 presents data in the Rockwell C hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.2 Conversion Table 2 presents data in the Rockwell B hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.3 Conversion Table 3 presents data on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of nickel and high-nickel alloys (nickel content o...

  8. Hard coatings

    International Nuclear Information System (INIS)

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)

  9. Structure and use of conceptual models in the Aespoe site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1998-09-01

    Early in the Aespoe project a need for structuring and clarification of the models used for different purposes was identified. The problem lied not in the numerical codes or the data base used for the modelling but rather in the process of how the real world was conceptualized into descriptive and predictive models. A proposal on how to structure these conceptual assumptions was made on which a standardised representation of used models was worked out. An essential objective has been to condensate the model descriptions to one page and still present the essential aspects of each model. It is hoped that in this way it is easier to obtain an overview of the assumptions underlying each model and facilitate comparison between different models. The base for the description is the `intended use of the model`. Based on the intended use the next step is to identify what `physical` processes should be included in the model. In some cases these processes can be represented by constitutive equations. The next step is to define the `concepts` needed to solve the problem. The concepts may be separated into four groups. Firstly, the type of `geometrical framework` and the framework-related parameters have to be defined. Secondly, the type of `material properties` to be assigned to the domains defined by the geometrical framework must be decided. Thirdly, the `spatial assignment method` of the material properties within a domain has to be described. Finally, the model normally has a limited extent and the `boundary conditions` have to be defined to compute or judge the effects within the model. For a real case the data can now be defined for the four groups of concepts by analysing measurements representing the actual case. If needed a `numerical or mathematical tool` that handles the processes and concepts should the be chosen. `Output parameters` of interest for model purposes must then be defined 7 refs, 2 tabs

  10. Structure and use of conceptual models in the Aespoe site investigations

    International Nuclear Information System (INIS)

    Early in the Aespoe project a need for structuring and clarification of the models used for different purposes was identified. The problem lied not in the numerical codes or the data base used for the modelling but rather in the process of how the real world was conceptualized into descriptive and predictive models. A proposal on how to structure these conceptual assumptions was made on which a standardised representation of used models was worked out. An essential objective has been to condensate the model descriptions to one page and still present the essential aspects of each model. It is hoped that in this way it is easier to obtain an overview of the assumptions underlying each model and facilitate comparison between different models. The base for the description is the 'intended use of the model'. Based on the intended use the next step is to identify what 'physical' processes should be included in the model. In some cases these processes can be represented by constitutive equations. The next step is to define the 'concepts' needed to solve the problem. The concepts may be separated into four groups. Firstly, the type of 'geometrical framework' and the framework-related parameters have to be defined. Secondly, the type of 'material properties' to be assigned to the domains defined by the geometrical framework must be decided. Thirdly, the 'spatial assignment method' of the material properties within a domain has to be described. Finally, the model normally has a limited extent and the 'boundary conditions' have to be defined to compute or judge the effects within the model. For a real case the data can now be defined for the four groups of concepts by analysing measurements representing the actual case. If needed a 'numerical or mathematical tool' that handles the processes and concepts should the be chosen. 'Output parameters' of interest for model purposes must then be defined

  11. Stochastic continuum hydrological model of Aespoe for the SITE-94 performance assessment project

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Y.Y.W. [Univ. of California, Berkeley, CA (United States). Earth Sciences Div.

    1996-06-01

    As part of the SKI SITE-94 deep repository performance assessment project, a stochastic continuum hydrological model conditioned on the point injection data from boreholes KAS02-08 is developed for the southern Aespoe Island. Both the more conductive fractures and the less permeable matrix are generated within the framework of a single continuum stochastic model based on nonparametric indicator geostatistics. In the stochastic model, the fracture zones are made distinct from the matrix by imposing a long range correlation structure for a small fraction ({approx} the highest 11%) of the hydraulic conductivity in the preferred planes of fracture zones. The issue of spatial variability, giving rise to uncertainty in transport results in the site characterization of a heterogeneous medium, was addressed. Simulations were carried out for 3D transport from point tracer sources at hundreds of locations in the medium. The breakthrough curves from each `point` source release is characterized by two parameters: the mean transport velocity and the dispersion coefficient. The results were presented as a statistical distribution of the transport parameters, thus quantifying the spatial variability in site characterization by flow and transport measurements. Results of flow and transport simulation in 3D were also used to illustrate the large spatial variability of `point` measurements, but that for spatially integrated quantities the uncertainty is reduced and results become less sensitive to correlation structure. Therefore it was suggested that spatially integrated quantities may be a more appropriate alternative choice of predictive quantities for performance assessment, in that they are more commensurate with the level of our ignorance of the strongly heterogeneous character of the medium. 14 refs, 37 figs.

  12. Analysis on influence of surface load to stress-strain characteristics of pipeline buried in hard rock region%地表载荷对硬岩区埋地管道应力应变影响分析∗

    Institute of Scientific and Technical Information of China (English)

    韩传军; 张瀚; 张杰; 李琦

    2015-01-01

    In order to study the influence of surface load on mechanical performance of pipeline buried in hard rock region, a pipeline-soil coupling 3D numerical model was built. The influences by magnitude of surface load, action area, inner pressure, radius-thickness ratio of pipeline and elasticity modulus of backfill soil on stress distribution, plastic strain and ovality of the pipeline were analyzed. The results showed that under the action of surface load, the high stress zone, which is oval, appears on the upside of the pipeline. With the increasing of surface load and force area, the high stress zone enlarges gradually, and the stress concentration appears on the left and right sides of the cross section in the pipeline. With the increasing of elasticity modulus of backfill soil, thickness and inner pressure of pipeline, the high stress zone shrinks, and the maximum equivalent stress decreases. The plastic strain zone appears on the upside of pipeline firstly, and it increases with the increasing of surface load and action length, but decreases with the increasing of elasticity modulus of backfill soil and thickness of pipeline. The plastic strain and plastic zone of pipeline decrease with the increasing of inner pressure when the inner pressure ranges from 0 to 4 MPa. The ovality of pipeline decreases with the increasing of elasticity modulus of backfill soil, thickness and in ner pressure of pipeline, but increases when the surface load increases.%为研究地表载荷对硬岩区埋地管道力学性能的影响,建立了管-土耦合三维数值模型,分析了地表载荷大小、作用面积、管道压力、管道径厚比及回填土弹性模量对管道应力分布、塑性应变、椭圆度的影响。结果表明:地表压载作用下,高应力区首先出现在管道顶部且呈椭圆形;随着地表载荷及其作用面积的增大,管道高应力区逐渐扩大,管道截面左右两侧也出现应力集中;随着回填土弹性模量

  13. Chemistry and origin of deep ground water in crystalline rocks; Kemi och genes av djupa grundvatten i kristallint berg

    Energy Technology Data Exchange (ETDEWEB)

    Lagerblad, B. [Swedish Cement and Concrete Research Inst., Stockholm (Sweden)

    1995-11-01

    This report discusses the interactions between water and crystalline rocks and its consequences for the chemical composition of the water. It also treats how flows of different types of water are modified by the rock, and the possible consequences for the ground water near a nuclear waste repository. The focus of the work is the changes in composition that ground water gets at deep levels in the rock. Data from Finnsjoen and Aespoe in Sweden show higher salinity in deep rock, which has been interpreted as a result of marine inflow of water during glaciation. Data from other, deeper boreholes in Finland, Canada, Russia, England and Sweden show that the increasing salinity is a rule and very high at great depths, higher than marine water can produce. Therefore, the deep waters from Finnsjoen and Aespoe are probably very old, and the high salinity a result from geological processes. Differing cation and isotopic composition than seawater also indicate geologic water. Differing theories on the origin of the ground water should be regarded in the safety analysis for a repository. 36 refs, 3 figs, 1 tab.

  14. Rock Stars

    Institute of Scientific and Technical Information of China (English)

    张国平

    2000-01-01

    Around the world young people are spending unbelievable sums of money to listen to rock music. Forbes Magazine reports that at least fifty rock stars have incomes between two million and six million dollars per year.

  15. KREEP Rocks

    Institute of Scientific and Technical Information of China (English)

    邹永廖; 徐琳; 欧阳自远

    2004-01-01

    KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and-14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.

  16. DECOVALEX-THMC Project. Task B. Understanding and characterizing the excavation disturbed zone (EDZ). Final Report (EDZ Guidance Document) Characterising and Modelling the Excavation Damaged Zone (EDZ) in Crystalline Rocks in the Context of Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, John A. (Imperial College and Rock Engineering Consultants (United Kingdom)); Baeckstroem, Ann; Lanru Jing (Royal lnstitute of Technology, Stockholm (Sweden)); Rutqvist, Jonny (Lawrence Berkeley National Laboratory (United States)) (eds.) (and others)

    2008-06-15

    This report is intended as a Guidance Document explaining current knowledge about the nature of and potential for thermo-hydro-mechanical-chemical modelling of the Excavation Damaged Zone (EDZ) around the excavations for an underground radioactive waste repository. In Part 1 of the report, the disturbances associated with excavation are explained together with reviews of Workshops that have been held on the subject. The manifold aspects of the EDZ are discussed under the three headings of the rock mass response to tunnelling, the influence of the excavation method, and EDZ characterisation methods. The evolution of the repository over thousands of years is qualitatively described via the subjects of time-dependent effects and stress redistribution, thermal effects, hydrogeological effects, and chemical effects. The first part of the document concludes with a discussion of uncertainties and limitations in measuring and characterising the EDZ. In Part 2 of the report, the results of a DECOVALEX research programme on modelling the EDZ are presented. Initially, the research involved the physical testing and computer modelling of the failure behaviour of a rock specimen in uniaxial compression. Four research teams used four different models to simulate the complete stress-strain curve for Aevroe granite from the Swedish Aespoe Hard Rock Laboratory. Conclusions are then made concerning the overall capabilities of these models. Subsequent research extended the work to computer simulation of the evolution of the repository using a 'wall block model' and a 'near-field model'. This included assessing the evolution of stress, failure and permeability and time dependent effects during repository evolution. In both sets of computer modelling, the types of codes used were an Elasto-Plastic Cellular Automaton (EPCA), the FRACOD boundary element (BEM) code with discrete fracture propagation, the THAMES finite element (FEM) code, and PFC, a distinct element

  17. DECOVALEX-THMC Project. Task B. Understanding and characterizing the excavation disturbed zone (EDZ). Final Report (EDZ Guidance Document) Characterising and Modelling the Excavation Damaged Zone (EDZ) in Crystalline Rocks in the Context of Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    This report is intended as a Guidance Document explaining current knowledge about the nature of and potential for thermo-hydro-mechanical-chemical modelling of the Excavation Damaged Zone (EDZ) around the excavations for an underground radioactive waste repository. In Part 1 of the report, the disturbances associated with excavation are explained together with reviews of Workshops that have been held on the subject. The manifold aspects of the EDZ are discussed under the three headings of the rock mass response to tunnelling, the influence of the excavation method, and EDZ characterisation methods. The evolution of the repository over thousands of years is qualitatively described via the subjects of time-dependent effects and stress redistribution, thermal effects, hydrogeological effects, and chemical effects. The first part of the document concludes with a discussion of uncertainties and limitations in measuring and characterising the EDZ. In Part 2 of the report, the results of a DECOVALEX research programme on modelling the EDZ are presented. Initially, the research involved the physical testing and computer modelling of the failure behaviour of a rock specimen in uniaxial compression. Four research teams used four different models to simulate the complete stress-strain curve for Aevroe granite from the Swedish Aespoe Hard Rock Laboratory. Conclusions are then made concerning the overall capabilities of these models. Subsequent research extended the work to computer simulation of the evolution of the repository using a 'wall block model' and a 'near-field model'. This included assessing the evolution of stress, failure and permeability and time dependent effects during repository evolution. In both sets of computer modelling, the types of codes used were an Elasto-Plastic Cellular Automaton (EPCA), the FRACOD boundary element (BEM) code with discrete fracture propagation, the THAMES finite element (FEM) code, and PFC, a distinct element particle flow code. In

  18. On regional flow in Baltic shield rock. An application of an analytical solution using hydrogeologic conditions at Aberg, Beberg, and Ceberg of SR97

    International Nuclear Information System (INIS)

    This report is one of many in support of SR 97, and is an analysis of the residence and transport times of a fluid particle at the three hypothetical domains of SR 97. The three domains are arbitrary named Aberg, Beberg and Ceberg. The report is intended to provide a quantitative assessment of the lateral length scales governing groundwater flow. The largest of these scales is believed to govern regional flow, i.e., flow at great depth. The calculated reference times presented in this report are fairly constant with the shortest reference time for Ceberg and the longest for Beberg. The difference in the calculated reference times are mainly due to the obtained differences in the lateral length scales at the three domains. However, the calculated residence times are extremely long. The corresponding transport times are very different from those obtained by means of numerical modeling of regional flow at Aberg, Beberg and Ceberg. The value is also contradicted by recent hydrochemical composition analyses of deep groundwater at Laxemar and Aespoe. A speculative interpretation of this result is that large scale regional flow, in the sense of meaning flow paths with long lateral extent, should be questioned for the kind of depth (500 m) and hydrogeologic system (hard rock) dealt with in this report. In other words, large scale regional flow may play a role for a repository at great depth (>>500 m), whereas non-periodic local variations in the topography may govern the flow pattern at moderate depths, e.g., depths less than 1000 m. There are several observations which support this interpretation

  19. Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Tasks 6D, 6E, 6F and 6F2

    International Nuclear Information System (INIS)

    This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization and performance assessment approaches to modelling solute transport in fractured rock. The objectives of Task 6 are: To assess simplifications used in Performance Assessment (PA) models. To determine how, and to what extent, experimental tracer and flow experiments can constrain the range of parameters used in PA models. To support the design of Site Characterisation (SC) programmes to ensure that the results have optimal value for performance assessment calculations. To improve the understanding of site-specific flow and transport behaviour at different scales using site characterisation models. The present report is concerned with Tasks 6D, 6E, 6F and 6F2. It follows on from two previous reviews of Tasks 6A, 6B and 6B2, and Task 6C. In Task 6D the transport of tracers through a fracture network is modelled using the conditions of the C2 TRUE-Block Scale tracer test, based on the synthetic structural model developed in Task 6C. Task 6E extends the Task 6D transport calculations to a reference set of PA time scales and boundary conditions. Task 6F consists of a series of 'benchmark' studies on single features from the Task 6C hydrostructural model in order to improve the understanding of differences between the participating models. Task 6F2 utilises models set up for Tasks 6E and 6F to perform additional sensitivity studies with the aim of increasing the understanding of how models behave, the reason for differences in modelling results, and the sensitivity of models to various assumptions and parameter values. Eight modelling teams representing five organisations participated in this exercise using Discrete Fracture Network (DFN), continuum and channel network concepts implemented in a range of different codes and

  20. Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Tasks 6D, 6E, 6F and 6F2

    Energy Technology Data Exchange (ETDEWEB)

    Hodgkinson, David (Quintessa, Henley-on-Thames (GB))

    2007-09-15

    This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization and performance assessment approaches to modelling solute transport in fractured rock. The objectives of Task 6 are: To assess simplifications used in Performance Assessment (PA) models. To determine how, and to what extent, experimental tracer and flow experiments can constrain the range of parameters used in PA models. To support the design of Site Characterisation (SC) programmes to ensure that the results have optimal value for performance assessment calculations. To improve the understanding of site-specific flow and transport behaviour at different scales using site characterisation models. The present report is concerned with Tasks 6D, 6E, 6F and 6F2. It follows on from two previous reviews of Tasks 6A, 6B and 6B2, and Task 6C. In Task 6D the transport of tracers through a fracture network is modelled using the conditions of the C2 TRUE-Block Scale tracer test, based on the synthetic structural model developed in Task 6C. Task 6E extends the Task 6D transport calculations to a reference set of PA time scales and boundary conditions. Task 6F consists of a series of 'benchmark' studies on single features from the Task 6C hydrostructural model in order to improve the understanding of differences between the participating models. Task 6F2 utilises models set up for Tasks 6E and 6F to perform additional sensitivity studies with the aim of increasing the understanding of how models behave, the reason for differences in modelling results, and the sensitivity of models to various assumptions and parameter values. Eight modelling teams representing five organisations participated in this exercise using Discrete Fracture Network (DFN), continuum and channel network concepts implemented in a range of different

  1. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    Energy Technology Data Exchange (ETDEWEB)

    Risberg, Jan [Stockholm Univ. (Sweden). Dept. of Quaternary Research

    2002-12-01

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  2. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    International Nuclear Information System (INIS)

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  3. Recorded corrosion rates on copper electrodes in the Prototype Repository at the Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, Bo [Rosborg Consulting, Nykoeping (Sweden)

    2013-04-15

    Real-time corrosion monitoring by means of electrochemical methods has been applied in an effort to measure corrosion rates of pure copper in the Prototype Repository at the Aspo Hard Rock Laboratory. Copper electrodes were installed in bentonite blocks on top of the electrically heated copper canisters in two deposition holes (dh). Three nominally identical cylindrical copper electrodes were installed in dh 1 and another three in dh 5 a few days before the heat was turned on to the canisters in September 2001 and in May 2003 respectively. The temperature of the copper electrodes has been around 30 deg C in dh 1 and somewhat below 35 deg C in dh 5. Real-time corrosion monitoring for both electrode setups was first applied in January 2004, and then periodically in 2005, 2006, 2008, and most recently in the end of 2010 just before work to open the outer section of the Prototype Repository was started. The recorded corrosion rates fall below 1.3 {mu}m/year (using a default value of n=2 in the software to convert the corrosion current density to a penetration rate by means of Faraday's law, and with no correction applied for the used measuring frequency of 0.01 Hz; also disregarding highly scattered data obtained for the copper electrodes in dh 1 during 2010). While the recorded rates on the electrodes in dh 5 first increased from about 0.2 {mu}m/year in 2004 up to a maximum of 1.3 {mu}m/year a year later (the drainage of the inner and outer sections was temporary closed in the end of 2004), and then gradually decreased to 0.7 {mu}m/year in the end of 2010, the recorded rates on the electrodes in dh 1 show a quite different picture. The recorded rates fall in the range 0.4-0.7 {mu}m/year and do not reflect any obvious decrease. However, it is anticipated that a similar time dependence as observed for the electrodes in dh 5 could have been present early on in the exposure; the electrodes were installed in 2001 but the first measurements were performed in 2004. Also

  4. The rock resources of the Northern Emirates

    OpenAIRE

    Mitchell, Clive; Styles, Michael

    2011-01-01

    The Rock Resources of the Northern Emirates The United Arab Emirates (UAE) has vast resources of limestone and hard rock in the northern Emirates. These are currently exploited by quarrying companies to produce construction aggregate and raw material for the manufacture of cement, with a small amount being used to produce rock wool, dimension stone and mineral filler. The demand by industry for higher value mineral products that could be produced from these resources is mostly met by impor...

  5. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  6. Stability of Hardly Reshaping Berm Breakwaters

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Van der Meer, Jentsje W.; Burcharth, Hans F.;

    2012-01-01

    The present paper deals with stability of berm breakwaters designed to be hardly or sometimes partly reshaping. Burcharth (2008, 2011) showed by comparison to the performance of a prototype berm breakwater that the Van der Meer formulae for stability of conventional rock armour including low cres...

  7. Development and applications of the channel network model for simulations of flow and solute transport in fractured rock

    International Nuclear Information System (INIS)

    The Channel Network model and its computer implementation, the code CHAN3D, for simulations of fluid flow and transport of solutes have been developed. The tool may be used for performance and safety assessments of deep lying repositories in fractured rocks for nuclear and other hazardous wastes, e.g. chemical wastes. It may also be used to simulate and interpret field experiments of flow and transport in large or small scale. Fluid flow and solute transport in fractured media are of interest in the performance assessment of a repository for hazardous waste, located at depth in crystalline rock, with potential release of solutes. Fluid flow in fractured rock is found to be very unevenly distributed due to the heterogeneity of the medium. The water will seek the easiest path, channels, under a prevailing pressure gradient. Solutes in the flowing water may be transported through preferential paths and migrate from the water in the fractures into the stagnant water in the rock matrix. There, sorbing solutes may be sorbed on the micro surfaces within the matrix. The diffusion into the matrix and the sorption process may significantly retard the transport of species and increase the time available for radionuclide decay. Channelling and matrix diffusion contribute to the dispersion of solutes in the water. Important for performance assessment is that channeling may cause a portion of the solutes to arrive much faster than the rest of the solutes. Simulations of field experiments at the Aespoe Hard Rock Laboratory using the Channel Network model have been performed. The application of the model to the site and the simulation results of the pumping and tracer tests are presented. The results show that the model is capable of describing the hydraulic gradient and of predicting flow rates and tracer transport obtained in the experiments. The data requirements for the Channel Network model have been investigated to determine which data are the most important for predictions

  8. Intra-terrestrial Biosorption of Radionuclides and Analogous Trace Elements. Microbial Interference with the 'Water/Rock Interface'

    International Nuclear Information System (INIS)

    The Swedish nuclear fuel management company (SKB) has instigated final site investigations for a deep subsurface high level nuclear waste (HLW) repository in granitic rock. This facility will be situated 500 meters below ground level and will isolate the HLW from the environment using an engineered multi-barrier system with a supposed design life of 105 to 106 years. As microbial life is ubiquitous in intra-terrestrial environments, assessing the subsurface geochemical and geomicrobial influences is critical for predicting the safety and longevity of HLW storage. In the possible event of repository failure, the transport of radionuclides through water conducting rock fractures is the predominant concern but radionuclide migration can be retarded by abiotic and biotic sorption processes. In this study biofilms were grown under in situ pressures and conditions using groundwater sourced from boreholes 296 m to 450m below sea level at the Aespoe hard rock laboratory (IM) in Sweden. Purpose built biofilm reactors were installed and left to develop microbial communities for up to one year. The community genera were then analysed genetically along with the population characteristics. Scintillation, NaI Y-detection, ICP-MS and autoradiography were used to investigate the ability of these biofilms to absorb trace metals from fracture fluids and synthetic groundwater containing Co, Pm, Np, Am, Th, U and Mo. The concentrations of PGE (platinum group elements) and REE (rare earth elements) were also measured by ICP-MS for experiments conducted in aerobic conditions. Results indicate that aerobic biofilms grown in near neutral pH conditions, with low pressure (1 bar) and oxygen (<1.5 mg/l; Eh <190 mV), can rapidly attenuate metals to over 1000-fold higher than the levels within the groundwater. In anaerobic conditions biofilms in 1.5 % salt and near neutral pH tend to favour the adsorption of the 3+ valence state (Am, Pm) over other radionuclides such as Co, Th, Np, U and Mo

  9. Differentiation and analysis on rock breaking characteristics of TBM disc cutter at different rock temperatures

    Institute of Scientific and Technical Information of China (English)

    谭青; 张桂菊; 夏毅敏; 李建芳

    2015-01-01

    In order to study rock breaking characteristics of tunnel boring machine (TBM) disc cutter at different rock temperatures, thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated. Furthermore, by using the linear cutting experiment platform, rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments. Finally, rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective. The results indicate the follows. 1) When rock temperature increases, the mechanical properties of rock such as hardness, and strength, were greatly reduced, simultaneously the microcracks rapidly grow with the cracks number increasing, which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter. 2) The higher the rock temperature, the lower the rock internal stress. The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller. 3) The higher the rock temperature is, the more the numbers of micro, tensile and shear cracks produced are by rock as well as the easier the rock intrusion, along with shear failure mode mainly showing. 4) With rock temperature increasing, the resistance intrusive coefficients of rock and intrusion power decrease obviously, so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently. 5) The acoustic emission frequency remarkably increases along with the temperature increasing, which improves the rock breaking efficiency.

  10. 高应力硬岩卸荷岩爆的劈裂判据及因素敏感性分析%Splitting criterion of unloading rock burst for high-stress hard rock and its sensitivity analysis of factors

    Institute of Scientific and Technical Information of China (English)

    张晓君

    2013-01-01

    针对现有岩爆研究的不足,基于突变理论建立了围岩卸荷岩爆的劈裂突变模型,得到了考虑卸荷影响的劈裂岩爆必要条件和充分条件并在此基础上进行了因素敏感性分析.研究表明,开挖卸荷致拉明显降低了突变特征值及岩爆发生的门槛,使岩爆发生的可能性大为增加,而且当拉应力σx=πσt/4时,必要条件就成为充分条件;卸荷后一段时间围岩发生变形,达到发生岩爆至少所需的卸荷细观拉应力,形成标准或滞后岩爆模式;竖向应力达到一定值,围岩卸荷瞬间其突变特征值△≤0,形成瞬时岩爆模式;岩爆劈裂要满足一定的临空面尺寸要求,随竖向应力的增大这种要求明显减弱;发生岩爆时岩爆区释放的能量△E,σx,△对竖向应力的敏感性很强,△对σ3极为敏感.%In this paper, aiming at the existing defects of rock burst study, a splitting catastrophe model of unloading rock burst of surrounding rock was established based on the mutation theory, and the necessary and sufficient conditions of splitting rock burst were obtained while considering the unloading influence, then the sensitivity of influence factors was further analyzed. The results show that the mutation characteristic value and critical condition of rock burst were reduced obviously by excavation unloading, and the occurrence possibility of rock burst increases greatly, when the tensile stress meets the condition of σχ=πσt/4, the necessary conditions will become the sufficient conditions. Meanwhile, the surrounding rock will be displaced after a period of unloading, the standard or delayed rock burst will occur when the unloading microscopic tensile stress reaches the needed condition to induce rock burst, while the instant rock burst occur will occur when the vertical stress reaches to a certain value and the mutation characteristic value of surrounding rock during unloading moment meets the condition of △≤0. In

  11. Hard hadronic diffraction is not hard

    CERN Document Server

    Kopeliovich, Boris; Potashnikova, Irina

    2016-01-01

    Hadronic diffractive processes characterised by a hard scale (hard diffraction) contain a nontrivial interplay of hard and soft, nonperturbative interactions, which breaks down factorisation of short and long distances. On the contrary to the expectations based on the factorization hypothesis, assuming that hard diffraction is a higher twist, these processes should be classified as a leading twist. We overview various implications of this important observation for diffractive radiation of Abelian (Drell-Yan, gauge bosons, Higgs boson) and non-Abelian (heavy flavors) particles, as well as direct coalescence into the Higgs boson of the non-perturbative intrinsic heavy flavour component of the hadronic wave function.

  12. THM-issues in repository rock. Thermal, mechanical, thermo-mechanical and hydro-mechanical evolution of the rock at the Forsmark and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Hoekmark, Harald; Loennqvist, Margareta; Faelth, Billy (Clay Technology AB, Lund (Sweden))

    2010-05-15

    even in the hottest ones. To account for uncertainties in the thermal calculations, the layout is established with a margin of about 5 deg C to the 100 deg C limit. It is demonstrated here that the spatial variability of rock heat transport properties means that there is considerable robustness in the design approach. An underestimate of the uncertainty margin by a few degrees appears to impact on very few canisters, even under the conservative assumption that all deposition holes are completely dry. Spalling after excavation of a deposition hole excavation is not likely unless the major horizontal stress is aligned off the orientation of the tunnel axis by the largest angle given within the uncertainty range of the Forsmark in situ stress model. In case it happens, the spalling will be limited to the top 1 m of the deposition hole for the most likely Forsmark major stress magnitude and to the top 3 m for the upper bound stress magnitude. Thermally-induced spalling is almost certain to occur after some time of heating, i.e. also for the most favourable conditions regarding stress orientation and magnitude. However, for the most favourable conditions the spalling will occur late and be limited to the top 5 m of the deposition hole. All spalling risk estimates are based on the assumption that the spalling strength varies between 52% and 62% of the uniaxial compressive strength of the intact rock, as suggested by field experiments performed in the Aespoe Hard Rock Laboratory. It is also assumed that the deposition holes are completely dry, i.e. without any swelling pressure to support and stabilize the walls. These assumptions are all claimed to be conservative. The stress path for rock in the walls of KBS-3 deposition holes will be different from corresponding stress paths in the field experiments and a small support pressure, possibly sufficient to limit the extent of the spalling, will be found also in dry deposition holes. Transmissivity effects on rock fractures are

  13. THM-issues in repository rock. Thermal, mechanical, thermo-mechanical and hydro-mechanical evolution of the rock at the Forsmark and Laxemar sites

    International Nuclear Information System (INIS)

    even in the hottest ones. To account for uncertainties in the thermal calculations, the layout is established with a margin of about 5 deg C to the 100 deg C limit. It is demonstrated here that the spatial variability of rock heat transport properties means that there is considerable robustness in the design approach. An underestimate of the uncertainty margin by a few degrees appears to impact on very few canisters, even under the conservative assumption that all deposition holes are completely dry. Spalling after excavation of a deposition hole excavation is not likely unless the major horizontal stress is aligned off the orientation of the tunnel axis by the largest angle given within the uncertainty range of the Forsmark in situ stress model. In case it happens, the spalling will be limited to the top 1 m of the deposition hole for the most likely Forsmark major stress magnitude and to the top 3 m for the upper bound stress magnitude. Thermally-induced spalling is almost certain to occur after some time of heating, i.e. also for the most favourable conditions regarding stress orientation and magnitude. However, for the most favourable conditions the spalling will occur late and be limited to the top 5 m of the deposition hole. All spalling risk estimates are based on the assumption that the spalling strength varies between 52% and 62% of the uniaxial compressive strength of the intact rock, as suggested by field experiments performed in the Aespoe Hard Rock Laboratory. It is also assumed that the deposition holes are completely dry, i.e. without any swelling pressure to support and stabilize the walls. These assumptions are all claimed to be conservative. The stress path for rock in the walls of KBS-3 deposition holes will be different from corresponding stress paths in the field experiments and a small support pressure, possibly sufficient to limit the extent of the spalling, will be found also in dry deposition holes. Transmissivity effects on rock fractures are

  14. Use of site specific data from Aespoe - preliminary results from the on-going safety analysis SR 97

    International Nuclear Information System (INIS)

    This paper discusses an on-going safety assessment study of SKB as well as the use of field data from Aespoe for obtaining input parameters for flow and radionuclide transport modelling in the geosphere. In the on-going Safety Assessment study SR 97, three individual sites in Sweden are used for exemplifying site specific conditions on overall repository performance. Thus, models capable of reproducing site specific characteristics are utilised. This is primarily obtained by implementing the geologic structural models in suitable conceptual models for groundwater flow on both regional and local scales. The models for flow incorporate observed and/or inferred water conducting features as well as other site-specific characteristics necessary for realistic descriptions of flow at the sites. The flow modelling thus aims at realism; the results obtained for present day conditions should not in any serious aspect conflict with observations at the site. Agreement between observed and modelled entities provides confidence in that a sound understanding of the site is obtained. Aespoe is one of the three sites providing site-specific conditions in SR 97. Transport is subsequently modelled using a stream tube approach where the 'travel times', for non-sorbing species, and discharge locations of a set of one-dimensional stream tubes are obtained from particle tracking in the flow model. The resulting distribution of 'travel times' in a single model realisation reflects the spatial variability and spatial extent of the repository, whereas the ensemble travel time distribution (over several realisations) for a given canister location reflects the uncertainty in travel time. The actual transport paths used in the transport modelling are thus dependent on site specific information such as e.g. existence of water conductive features. Other input parameters to the transport model are based on more generic and/or conservative arguments. However, the goal in a safety assessment

  15. DECOVALEX III/BENCHPAR PROJECTS. Evaluation of the Impact of Thermal-Hydro-Mechanical Couplings in Bentonite and Near-Field Rock Barriers on a Nuclear Waste Repository in a Sparsely Fractured Hard Rock. Report of BMT1C/WP2

    International Nuclear Information System (INIS)

    This report presents the works performed for the third, also the last, phase (BMT1C) of BMT1 of the DECOVALEX III project for the period of 1999-2002. The works of BMT1 is divided into three phases: BMT1A, BMT1B and BMT1C. The BMT1A concerns with calibration of the computer codes with a reference Thermal (T), Hydrological (H) and Mechanical (M) experiment at Kamaishi Mine, Japan. The objective is to validate the numerical approaches, computer codes and material models, so that the teams simulating tools are at a comparable level of maturity and sophistication. The BMT1B uses the calibrated codes to perform scoping calculations, considering varying degrees of THM coupling and varying permeability values of the surrounding rock for a reference generic repository design without fractures. The aim is to identify the coupling mechanisms of importance for construction, performance and safety of the repository. BMT1C concerns with scoping calculations with different coupling combinations for the case where a horizontal fracture intersects the deposition hole and a vertical fracture zone divides two adjacent deposition tunnel/hole system. A hydrostatic condition is applied along the vertical fracture as a hydraulic boundary condition. In addition, the SKI/KTH team performed an additional calculation case of a highly fractured rock mass with two orthogonal sets of fractures with a spacing of 0.5 m. The chosen measures for evaluating the long term safety and performance of the repository are the maximal temperature created by the thermal loading from the emplaced wastes, the time for resaturation of the buffer, the maximal swelling stress developed in the buffer, the structural integrity of the rock mass and the permeability evolution in the rock mass. The analyses fro BMT1C were conducted by four research teams: SKI/KTH (Sweden), CNSC (Canada), IRSN/CEA(France) and JNC (Japan), using FEM approach with different computer codes. From the results, it is clear that the

  16. DECOVALEX III/BENCHPAR PROJECTS. Evaluation of the Impact of Thermal-Hydro-Mechanical Couplings in Bentonite and Near-Field Rock Barriers on a Nuclear Waste Repository in a Sparsely Fractured Hard Rock. Report of BMT1C/WP2

    Energy Technology Data Exchange (ETDEWEB)

    Jing, L. [Royal Inst. of Technology, Stockholm (Sweden). Engineering Geology; Nguyen, T.S. [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)] (eds.)

    2005-02-15

    This report presents the works performed for the third, also the last, phase (BMT1C) of BMT1 of the DECOVALEX III project for the period of 1999-2002. The works of BMT1 is divided into three phases: BMT1A, BMT1B and BMT1C. The BMT1A concerns with calibration of the computer codes with a reference Thermal (T), Hydrological (H) and Mechanical (M) experiment at Kamaishi Mine, Japan. The objective is to validate the numerical approaches, computer codes and material models, so that the teams simulating tools are at a comparable level of maturity and sophistication. The BMT1B uses the calibrated codes to perform scoping calculations, considering varying degrees of THM coupling and varying permeability values of the surrounding rock for a reference generic repository design without fractures. The aim is to identify the coupling mechanisms of importance for construction, performance and safety of the repository. BMT1C concerns with scoping calculations with different coupling combinations for the case where a horizontal fracture intersects the deposition hole and a vertical fracture zone divides two adjacent deposition tunnel/hole system. A hydrostatic condition is applied along the vertical fracture as a hydraulic boundary condition. In addition, the SKI/KTH team performed an additional calculation case of a highly fractured rock mass with two orthogonal sets of fractures with a spacing of 0.5 m. The chosen measures for evaluating the long term safety and performance of the repository are the maximal temperature created by the thermal loading from the emplaced wastes, the time for resaturation of the buffer, the maximal swelling stress developed in the buffer, the structural integrity of the rock mass and the permeability evolution in the rock mass. The analyses fro BMT1C were conducted by four research teams: SKI/KTH (Sweden), CNSC (Canada), IRSN/CEA(France) and JNC (Japan), using FEM approach with different computer codes. From the results, it is clear that the

  17. Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

    International Nuclear Information System (INIS)

    A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed

  18. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  19. Rock mass response during high pressure grouting

    OpenAIRE

    Gothäll, Rikard

    2006-01-01

    The sealing of hard jointed rock by grouting involves several complicated mechanical systems. The result is a complex coupled system of hydro- logical and mechanical precesses. In order to determine the higher order effects of the resulting system the fracture deformations must be assessed. This requires a model that mimics the mechanical behaviour of not only fractures under normal load but also the entire rock mass system. This model indicates that there are two dominant regimes involved; a...

  20. 大同矿区"三硬"煤层巷道煤壁整体推出型冲击地压发生机理的研究%Research on the rock burst mechanism of coal tunnel wall being pushing out overall in Datong coal mining area′s "three hard" coal roadway

    Institute of Scientific and Technical Information of China (English)

    王旭宏; 康立勋; 杨双锁

    2009-01-01

    建立了大同矿区"三硬"煤层巷道煤壁整体推出型冲击地压的数学力学模型,研究了整体推出型冲击地压发生的力学机理.认为在煤层与顶板已经离层的条件下,发生煤体整体移动所需的垂直应力的值很小,易发生煤体被挤出、整体向外移动的现象.%By establishing the mathematical model about the rock burst type of coal wall overall being pushed out in "three hard" coal roadway of Datong Coal Mining Area, the writer studied the mechanism of this type. Under the condition of having separated the seam and roof, the occurrence of coal as a whole to be moved and of having the vertical stress is very small, because it′s possible to happen that the coal is vulnerably squeezed out and moved outward as a whole.

  1. Ordering of hard particles between hard walls

    Science.gov (United States)

    Chrzanowska, A.; Teixeira, P. I. C.; Ehrentraut, H.; Cleaver, D. J.

    2001-05-01

    The structure of a fluid of hard Gaussian overlap particles of elongation κ = 5, confined between two hard walls, has been calculated from density-functional theory and Monte Carlo simulations. By using the exact expression for the excluded volume kernel (Velasco E and Mederos L 1998 J. Chem. Phys. 109 2361) and solving the appropriate Euler-Lagrange equation entirely numerically, we have been able to extend our theoretical predictions into the nematic phase, which had up till now remained relatively unexplored due to the high computational cost. Simulation reveals a rich adsorption behaviour with increasing bulk density, which is described semi-quantitatively by the theory without any adjustable parameters.

  2. Rock stresses (Grimsel rock laboratory)

    International Nuclear Information System (INIS)

    On the research and development project 'Rock Stress Measurements' the BGR has developed and tested several test devices and methods at GTS for use in boreholes at a depth of 200 m and has carried out rock mechanical and engineering geological investigations for the evaluation and interpretation of the stress measurements. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on hollow cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure and vertical stresses which agree well with the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are generally lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (orig./HP)

  3. A channel-network-model for radionuclide transport in fractured rock -- Testing against field data

    International Nuclear Information System (INIS)

    A new model concept for describing flow and transport in fractured rock has been tested on some field tracer experiments. The flowing water in the rock is envisaged to take place in a three-dimensional network of channels with stochastic properties. For times of interest for deep geological repositories for nuclear waste it has been found that the volume of the channels, i.e. the flow porosity of the rock, has no practical influence on the Residence Time Distribution of the nuclides. It is totally dominated by the matrix diffusion effects. The specific Flow Wetted Surface, FWS, of the channels therefore needs to be known. A method to evaluate the FWS from hydraulic measurements in boreholes is presented. Tracer tests at the swedish Aespoe rock laboratory have been predicted using this model and data obtained in the way outlined in the paper. The main tracer test was predicted reasonably well without using any adjustable parameters. Some other tracers also used were not detected in the tests as they were expected to be. The authors discuss some of the possible reasons for this in relation to geological observations made in the expected pathways for these tracers. The sensitivity of results to uncertainties in parameter values is also discussed

  4. Effect of coatings on hardness of commercial marbles

    Science.gov (United States)

    Zedef, Veysel

    2016-04-01

    In this study, three type of marble and one granite were chosen to understand if the coating is effective on hardness of the commercial rocks. To understand the hardness of the rock, Schmidt hammer tests were undertaken. The used device allowed us uniaxial compressive strength (UCS) as well as Schmidt rebound (R). The coated samples have clearly high R and UCS values when compared to uncoated samples. The Elazig visne, the well-known marble of Turkey, have 35.6 R and 44.2 MPa UCS values of coated samples. On the other hand, uncoated surface of the same marble have 30.5 R and 35.4 MPa UCS.

  5. Comprehensive hard materials

    CERN Document Server

    2014-01-01

    Comprehensive Hard Materials deals with the production, uses and properties of the carbides, nitrides and borides of these metals and those of titanium, as well as tools of ceramics, the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials), milling, granulation, cold and hot compaction, sintering, hot isostatic pressing, hot-pressing, injection moulding, as well as on the coating technologies for refractory metals, hard metals and hard materials. The characterization, testing, quality assurance and applications are also covered. Comprehensive Hard Materials provides meaningful insights on materials at the leading edge of technology. It aids continued research and development of these materials and as such it is a critical information resource to academics and industry professionals facing the technological challenges of the future. Hard materials operate at the leading edge of technology, and continued res...

  6. Mining technology development in crystalline rock

    International Nuclear Information System (INIS)

    The Colorado School of Mines (CSM), under sponsorship of the Department of Energy through the Office of Nuclear Waste Isolation (ONWI), has established a hard-rock research facility at its experimental mine. Even through this site will not become a nuclear waste repository, the CSM has established and maintains an underground test room for use by its own personnel and ONWI and its contractors to conduct in situ investigations. Furthermore, CSM is designing, conducting, and reporting on a series of field research programs to develop site evaluation procedures, excavation techniques, and instrumentation required for nuclear waste repository siting, construction, and monitoring (Hustrulid, 1981). This facility is presently being used to: evaluate and develop techniques for careful excavation of hard rock; develop the mapping techniques required to describe adequately the structural geology; evaluate the structural continuity in the granitic gneiss at the CSM site; evaluate the structural damage done to the rock mass by blasting; develop techniques for evaluating fracture permeability; evaluate permeability changes in the rock mass as a result of blasting. Although specifically oriented toward nuclear waste storage and disposal, the techniques and procedures being developed and evaluated have wide applicability to all underground excavations in hard rock

  7. A Rock Mechanics and Coupled Hydro mechanical Analysis of Geological Repository of High Level Nuclear Waste in Fractured Rocks

    International Nuclear Information System (INIS)

    This paper introduces a few case studies on fractured hard rock based on geological data from Sweden, Korea is one of a few countries where crystalline rock is the most promising rock formation as a candidate site of geological repository of high level nuclear waste. Despite the progress made in the area of rock mechanics and coupled hydro mechanics, extensive site specific study on multiple candidate sites is essential in order to choose the optimal site. For many countries concerned about the safe isolation of nuclear wastes from the biosphere, disposal in a deep geological formation is considered an attractive option. In geological repository, thermal loading continuously disturbs the repository system in addition to disturbances a recent development in rock mechanics and coupled hydro mechanical study using DFN(Discrete Fracture Network) - DEM(Discrete Element Method) approach mainly applied in hard, crystalline rock containing numerous fracture which are main sources of deformation and groundwater flow

  8. Determination of relationships between thermal conductivity and material properties of rocks

    Institute of Scientific and Technical Information of China (English)

    Kazim G(o)rgülü

    2004-01-01

    Energy transfer between the adjacent parts of rocks in underground mines is widely influenced by the thermal conductivity of rocks. The relationships between the thermal conductivity and some material properties of rocks such as the uniaxial compressive strength, unit mass, tensile strength, cohesion, Young's modulus, point load strength, Schmidt rebound hardness, Shore scleroscope hardness and toughness strength were investigated. The statistical analysis of the data obtained in laboratory tests shows that the thermal conductivity increases with increasing the uniaxial compressive strength, unit mass, tensile strength, cohesion, Young's modulus, point load strength, Schmidt rebound hardness and Shore scleroscope hardness, and decreases with increasing the toughness strength.

  9. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  10. Structural Discrimination – Between a Rock and a Hard Place

    DEFF Research Database (Denmark)

    Skadegaard Thorsen, Mira

    is the tension or discrepancy that arises between acknowledged and unacknowledged experiences of discrimination. These include verbal as well as non-verbal communication, abstract and implicit social codes and behaviors, and embodied experience. The article is primarily theoretical, but takes its......This article examines challenges that arise when discrimination is expressed in communication across perceived differences (inter-cultural communication). More specifically, it looks at how visible minority Danes navigate in regard to structural discrimination (implicit and underlying forms of...... discrimination) imbricated in seemingly neutral everyday communication. It argues that structural discrimination is discursive and constitutive and is expressed in language as well as communicated in the form of naturalizations and embodiments of discrimination. It suggests that structural discrimination is so...

  11. Radioactive waste - Between a rock and a hard place

    International Nuclear Information System (INIS)

    Full text: Throughout the world, plans for repositories face difficulties. The search for sites has found difficulties in France, Sweden, Switzerland and most recently in the UK. This is despite massive public relations exercises and, in the case of the UK and Switzerland, broad-based local support for the project. Tom Cur-tin will present a view on the lessons to be learnt from the Nirex project and give some pointers on the sociology and politics involved in the disposal of radioactive waste. This paper will review the sociology and politics of radioactive waste disposal. Lessons Learnt: It is not just a scientific process: The fundamental lesson learrit from the Nirex experience so far is that the process is not merely scientific; The project has to succeed politically: To concentrate on the technical aspects of siting without considering the political aspect equates to building castles in the air; Any form of imposition leads to rejection: The prevailing feeling among some politicians was that the project was unfairly imposed; One player cannot support the whole edifice: One company cannot carry on its shoulder the entire weight of the project; Third parties must support the project: Another fundamental criterion of the political process is the active involvement of third parties. Summary: The developer cannot do all the work alone - a number of players are needed. Total control - for example, a timetable - is not possible as local communities must have power. Openness and transparency at all stages are essential and finally, and most importantly, politics comes before science, emotion before rational thought. Finally, delays are a part of long-lived projects. The objective is to manage them, not to be defeated by them

  12. Hardness and excitation energy

    Indian Academy of Sciences (India)

    Á Nagy

    2005-09-01

    The concept of the ensemble Kohn-Sham hardness is introduced. It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the limit → 0. It is proposed that the first excitation energy can be used as a reactivity index instead of the hardness.

  13. Induced spherococcoid hard wheat

    International Nuclear Information System (INIS)

    A mutant has been obtained - a spheroccocoid line -through irradiation of hard wheat seed with fast neutrons. It is distinguished by semispherical glumes and smaller grain; the plants have low stem with erect leaves but with shorter spikes and with lesser number of spikelets than those of the initial cultivar. Good productive tillering and resistance to lodging contributed to 23.5% higher yield. The line was superior to the standard and the initial cultivars by 14.2% as regards protein content, and by up to 22.8% - as to flour gluten. It has been successfully used in hybridization producing high-yielding hard wheat lines resistant to lodging, with good technological and other indicators. The possibility stated is of obtaining a spherococcoid mutant in tetraploid (hard) wheat out of the D-genome as well as its being suited to hard wheat breeding to enhance protein content, resistance to lodging, etc. (author)

  14. Hard probes 2006 Asilomar

    CERN Multimedia

    2006-01-01

    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  15. Grouting methodology in crystalline rock

    International Nuclear Information System (INIS)

    For this paper, an initial literature review was conducted to investigate the potential applications of grouting technology for geological disposal of high level radioactive waste (hereafter called geological disposal), and the potential grouting material for each application. The results show the necessity of using suspension grout, such as cement-based grout, during excavation work, especially deep underground. Next, the method to achieve highly effective seals in crystalline rock with cement grout is studied. To enhance the sealing quality, cement grout should penetrate into very fine fractures, e.g. less than 100 μm aperture. In the case of suspension grout, clogging with grout at the openings of rock fractures, especially fine fractures, tends to occur, which results in poor grout penetration. A laboratory experiment was conducted to investigate the clogging phenomenon; the results suggest that high injection pressures could be effective to prevent clogging. Finally, focusing on pre-excavation grouting for horizontal tunnels in crystalline rock, the effective grout hole patterns for achieving high quality sealing was studied. A series of theoretical calculations for water inflow and cost studies were conducted. The results indicate that a dense arrangement of grout holes in a relatively narrow area around a tunnel section, as practised in the Nordic countries, is favorable in hard crystalline rock. (author)

  16. Hard coal; Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V., Herne (Germany)

    2013-04-01

    The year 2012 benefited from a growth of the consumption of hard coal at the national level as well as at the international level. Worldwide, the hard coal still is the number one energy source for power generation. This leads to an increasing demand for power plant coal. In this year, the conversion of hard coal into electricity also increases in this year. In contrast to this, the demand for coking coal as well as for coke of the steel industry is still declining depending on the market conditions. The enhanced utilization of coal for the domestic power generation is due to the reduction of the nuclear power from a relatively bad year for wind power as well as reduced import prices and low CO{sub 2} prices. Both justify a significant price advantage for coal in comparison to the utilisation of natural gas in power plants. This was mainly due to the price erosion of the inexpensive US coal which partly was replaced by the expansion of shale gas on the domestic market. As a result of this, the inexpensive US coal looked for an outlet for sales in Europe. The domestic hard coal has continued the process of adaptation and phase-out as scheduled. Two further hard coal mines were decommissioned in the year 2012. RAG Aktiengesellschaft (Herne, Federal Republic of Germany) running the hard coal mining in this country begins with the preparations for the activities after the time of mining.

  17. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  18. Hardness of metallic crystals

    Indian Academy of Sciences (India)

    Wuhui Li; Fengzhang Ren; Juanhua Su; Zhanhong Ma; Ke Cao; Baohong Tian

    2011-07-01

    This paper presents a new formula for calculating the hardness of metallic crystals, resulted from the research on the critical grain size with stable dislocations. The formula is = 6 /[(1 – )], where is the hardness, the coefficient, the shear modulus, the Poisson’s ratio, a function of the radius of an atom () and the electron density at the atom interface (). The formula will not only be used to testify the critical grain size with stable dislocations, but also play an important role in the understanding of mechanical properties of nanocrystalline metals.

  19. Hard exclusive QCD processes

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, W.

    2007-01-15

    Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)

  20. Redox zone II. Coupled modeling of groundwater flow, solute transport, chemical reactions and microbial processes in the Aespoe island

    International Nuclear Information System (INIS)

    The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behaviour and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by Banwart et al. Later, Banwart presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by Molinero who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulphate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of Molinero and extends the preliminary microbial model of Zhang by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfaphe concentration, thus adding additional evidence for the possibility

  1. Redox zone II. Coupled modeling of groundwater flow, solute transport, chemical reactions and microbial processes in the Aespoe island

    Energy Technology Data Exchange (ETDEWEB)

    Samper, Javier; Molinero, Jorge; Changbing Yang; Guoxiang Zhang [Univ. Da Coruna (Spain)

    2003-12-01

    The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behaviour and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by Banwart et al. Later, Banwart presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by Molinero who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulphate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of Molinero and extends the preliminary microbial model of Zhang by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfaphe concentration, thus adding additional evidence for the possibility

  2. Rock et Cinéma

    OpenAIRE

    Bart, Christian Le; Didelot, Jérôme; Eizykman, Claudine; Gorin, François; Grünberg, Serge; Jousse, Thierry; Juiller, Laurent; Le Guern, Philippe; Leveratto, Jean-Marc; Neyrat, Cyril; ribac, françois; Siclier, Sylvain

    2006-01-01

    This special issue of Volume ! is dedicated to the relationships between rock music and cinema. It was published during the second edition of the Paris-Cinéma Festival. Its articles analyze the use of rock 'n' roll in various films: Phantom of Paradise by Brian De Palma, Exploding Plastic Inevitable by Andy Warhol with The Velvet Underground's music, A Hard Day's Night by Richard Lester, David Lynch movies, as well as Frank Zappa, Aphex Twin and "kinok". Ce hors-série de Volume ! est consa­c...

  3. Running in Hard Times

    Science.gov (United States)

    Berry, John N., III

    2009-01-01

    Roberta Stevens and Kent Oliver are campaigning hard for the presidency of the American Library Association (ALA). Stevens is outreach projects and partnerships officer at the Library of Congress. Oliver is executive director of the Stark County District Library in Canton, Ohio. They have debated, discussed, and posted web sites, Facebook pages,…

  4. Experimental study on the physical and chemical properties of the deep hard brittle shale

    OpenAIRE

    Jian Xiong; Xiangjun Liu; Lixi Liang; Yi Ding; Meng Lei

    2016-01-01

    In the hard brittle shale formation, rock composition, physical and chemical properties, mechanics property before and after interacting with fluid have direct relation with borehole problems, such as borehole wall collapse, mud loss, hole shrinkage. To achieve hard brittle shale micro-structure, physical–chemical properties and mechanics property, energy-dispersive X-ray diffraction (XRD), cation exchange capacity experiment and hardness test are conducted. The result of laboratory experimen...

  5. Energy analysis for damage and catastrophic failure of rocks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The development history and current state of studies on the characteristics and mechanisms of deformation and failure of rock materials were briefly reviewed from the viewpoint of energy.The main scope and the achievable objectives of the energy-based research system were expatiated.It was validated by experiments that the damage process of rocks can be well described by the rock damage evolution equation established based on energy dissipation.It was found from the uniaxial compression and biaxial compression tests that only a small proportion of the total input energy in hard rocks is dissipated before peak load and a large proportion in soft rocks is dissipated before peak load.For both hard and soft rocks,the energy dissipated after peak load accounts for a greater proportion.More energy would be required for rock failure under equal biaxial compression than under unequal biaxial compression.The total absorbed energy is different for rock failure under high-rate loading and low-rate loading.More fragmented failure pattern usually corresponds to higher energy absorption.The mesoscopic analysis on the damage and failure of bedded salt rocks showed that the energy dissipation is prominent and the total absorbed energy for rock failure is low when cracks propagate in the weak mud interlayer while it is contrary when cracks propagate in the salt rock.The energy accumulation,transfer,dissipation and release during the failure process of tunnel with impending failure under disturbance were analyzed theoretically based on the elastoplastic mechanics theory.Furthermore,the spatial distribution of energy dissipation and energy release of fractured rocks under unloading was simulated numerically.It was demonstrated that energy is likely to be released from the weakest surface under compression,which triggers the global failure of rocks.

  6. Construction experiences from underground works at Oskarshamn. Compilation report

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Anders (Vattenfall Power Consultant AB, Stockholm (SE)); Christiansson, Rolf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

    2007-12-15

    The main objective with this report is to compile experiences from the underground works carried out at Oskarshamn, primarily construction experiences from the tunnelling of the cooling water tunnels of the Oskarshamn nuclear power units 1,2 and 3, from the underground excavations of Clab 1 and 2 (Central Interim Storage Facility for Spent Nuclear Fuel), and Aespoe Hard Rock Laboratory. In addition, an account is given of the operational experience of Clab 1 and 2 and of the Aespoe HRL on primarily scaling and rock support solutions. This report, as being a compilation report, is in its substance based on earlier published material as presented in the list of references. Approximately 8,000 m of tunnels including three major rock caverns with a total volume of about 550,000 m3 have been excavated. The excavation works of the various tunnels and rock caverns were carried out during the period of 1966-2000. In addition, minor excavation works were carried out at the Aespoe HRL in 2003. The depth location of the underground structures varies from near surface down to 450 m. As an overall conclusion it may be said that the rock mass conditions in the area are well suited for underground construction. This conclusion is supported by the experiences from the rock excavation works in the Simpevarp and Aespoe area. These works have shown that no major problems occurred during the excavation works; nor have any stability or other rock engineering problems of significance been identified after the commissioning of the Oskarshamn nuclear power units O1, O2 and O3, BFA, Clab 1 and 2, and Aespoe Hard Rock Laboratory. The underground structures of these facilities were built according to plan, and since than been operated as planned. Thus, the quality of the rock mass within the construction area is such that it lends itself to excavation of large rock caverns with a minimum of rock support

  7. Construction experiences from underground works at Oskarshamn. Compilation report

    International Nuclear Information System (INIS)

    The main objective with this report is to compile experiences from the underground works carried out at Oskarshamn, primarily construction experiences from the tunnelling of the cooling water tunnels of the Oskarshamn nuclear power units 1,2 and 3, from the underground excavations of Clab 1 and 2 (Central Interim Storage Facility for Spent Nuclear Fuel), and Aespoe Hard Rock Laboratory. In addition, an account is given of the operational experience of Clab 1 and 2 and of the Aespoe HRL on primarily scaling and rock support solutions. This report, as being a compilation report, is in its substance based on earlier published material as presented in the list of references. Approximately 8,000 m of tunnels including three major rock caverns with a total volume of about 550,000 m3 have been excavated. The excavation works of the various tunnels and rock caverns were carried out during the period of 1966-2000. In addition, minor excavation works were carried out at the Aespoe HRL in 2003. The depth location of the underground structures varies from near surface down to 450 m. As an overall conclusion it may be said that the rock mass conditions in the area are well suited for underground construction. This conclusion is supported by the experiences from the rock excavation works in the Simpevarp and Aespoe area. These works have shown that no major problems occurred during the excavation works; nor have any stability or other rock engineering problems of significance been identified after the commissioning of the Oskarshamn nuclear power units O1, O2 and O3, BFA, Clab 1 and 2, and Aespoe Hard Rock Laboratory. The underground structures of these facilities were built according to plan, and since than been operated as planned. Thus, the quality of the rock mass within the construction area is such that it lends itself to excavation of large rock caverns with a minimum of rock support

  8. Modelling of rock mass deformation for radioactive waste repositories in hard rock

    International Nuclear Information System (INIS)

    This report concerns a study which was conducted for the KBS project. The conclusions and viewpoints presented in the report are those of the author(s) and do not necessarily coincide with those of the client. (author)

  9. Rock shape, restitution coefficients and rockfall trajectory modelling

    Science.gov (United States)

    Glover, James; Christen, Marc; Bühler, Yves; Bartelt, Perry

    2014-05-01

    Restitution coefficients are used in rockfall trajectory modelling to describe the ratio between incident and rebound velocities during ground impact. They are central to the problem of rockfall hazard analysis as they link rock mass characteristics to terrain properties. Using laboratory experiments as a guide, we first show that restitution coefficients exhibit a wide range of scatter, although the material properties of the rock and ground are constant. This leads us to the conclusion that restitution coefficients are poor descriptors of rock-ground interaction. The primary problem is that "apparent" restitution coefficients are applied at the rock's centre-of-mass and do not account for rock shape. An accurate description of the rock-ground interaction requires the contact forces to be applied at the rock surface with consideration of the momentary rock position and spin. This leads to a variety of rock motions including bouncing, sliding, skipping and rolling. Depending on the impact configuration a wide range of motions is possible. This explains the large scatter of apparent restitution coefficients. We present a rockfall model based on newly developed hard-contact algorithms which includes the effects of rock shape and therefore is able to reproduce the results of different impact configurations. We simulate the laboratory experiments to show that it is possible to reproduce run-out and dispersion of different rock shapes using parameters obtained from independent tests. Although this is a step forward in rockfall trajectory modelling, the problem of parametersing real terrain remains.

  10. The rock diet

    OpenAIRE

    Fordyce, Fiona; Johnson, Chris

    2002-01-01

    You may think there is little connection between rocks and our diet, indeed a serving of rocks may sound very unappetising! But rocks are a vital source of the essential elements and minerals we need to keep us healthy, such as calcium for healthy teeth and bones.

  11. Theory of hard photoproduction

    International Nuclear Information System (INIS)

    The present theoretical knowledge about photons and hard photoproduction processes, i.e. the production of jets, light and heavy hadrons, quarkonia, and prompt photons in photon-photon and photon-hadron collisions, is reviewed. Virtual and polarized photons and prompt photon production in hadron collisions are also discussed. The most important leading and next-to-leading order QCD results are compiled in analytic form. A large variety of numerical predictions is compared to data from TRISTAN, LEP, and HERA and extended to future electron and muon colliders. The sources of all relevant results are collected in a rich bibliography. (orig.)

  12. Hard exclusive pion leptoproduction

    CERN Document Server

    Kroll, Peter

    2016-01-01

    In this talk it is reported on an analysis of hard exclusive leptoproduction of pions within the handbag approach. It is argued that recent measurements of this process performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. Within the handbag approach such gamma*_T -> pi transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that the handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. Predictions for other pseudoscalar meson channels are also briefly discussed.8 pages

  13. Rock History and Culture

    OpenAIRE

    Gonzalez, Éric

    2013-01-01

    Two ambitious works written by French-speaking scholars tackle rock music as a research object, from different but complementary perspectives. Both are a definite must-read for anyone interested in the contextualisation of rock music in western popular culture. In Une histoire musicale du rock (i.e. A Musical History of Rock), rock music is approached from the point of view of the people – musicians and industry – behind the music. Christophe Pirenne endeavours to examine that field from a m...

  14. EXPERIMENTAL STUDY OF ROCK BREAKING EFFECT OF STEEL PARTICLES

    Institute of Scientific and Technical Information of China (English)

    CUI Meng; ZHAI Ying-hu; JI Guo-dong

    2011-01-01

    Particle impact drilling is an efficient drilling technology for deep-well hard formation, With this technology, the rock is cut mainly by high-speed spherical particle impact under hydraulic action. In this article, the influence of jet flow factors, hydraulic factors and abrasive factors on rock breaking is studied through indoor experiments of impact by steel particles. The results indicate that the particle water jet has an optimal standoff distance and particle concentration; the rock breaking effect declines with the increase of the confining pressure and the decrease of the pump pressure and particle diameter. This study will provide some food of thought for the development of particle impact drilling technology.

  15. Molecular characterisation of dissolved organic matter (DOM) in groundwaters from the Aespoe Underground Research Laboratory (Sweden)): A novel 'finger printing' tool for palaeo-hydrological assessment

    International Nuclear Information System (INIS)

    The molecular signature of dissolved organic matter (DOM) in groundwaters can be used as a tool when investigating the palaeo-hydrological response of groundwater systems in relation to changes in recharge environment, and also for examining groundwater compartmentalisation, mixing and transport at underground repositories for radioactive waste. The DOM in groundwaters from two compartmentalised bodies of groundwater of distinctly different origin within the Aespoe Underground Research Laboratory (URL) (Sweden)) and in Baltic seawater has been isolated using tangential flow ultrafiltration (TUF) and dia-filtration. Recoveries of DOM ranged from 34.7 to 0.1 mg/L with substantial differences in the concentrations of the groundwaters collected only 120 m apart. Analysis by infrared spectroscopy (IR) and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) of the isolated DOM revealed that the groundwaters contained abundant alkylphenols which may represent heavily decomposed proteins or lignins originating from biopolymers contained within soils. The difference in the distribution and relative abundance of major pyrolysis products groups such as alkylphenols confirmed that the groundwater and Baltic seawater DOM samples were chemically distinct indicating minimal infiltration of marine groundwater derived by recharge from the Baltic or earlier Littorina Sea within the two compartmentalised groundwater bodies. (authors)

  16. Hard and Soft Governance

    DEFF Research Database (Denmark)

    Moos, Lejf

    2009-01-01

    The governance and leadership at transnational, national and school level seem to be converging into a number of isomorphic forms as we see a tendency towards substituting 'hard' forms of governance, that are legally binding, with 'soft' forms based on persuasion and advice. This article analyses...... and discusses governance forms at several levels. The first layer is the global: the methods of 'soft governance' that are being utilised by transnational agencies. The second layer is the national and local: the shift in national and local governance seen in many countries, but here demonstrated in...... the case of Denmark, and finally the third layer: the leadership used in Danish schools. The use of 'soft governance' is shifting the focus of governance and leadership from decisions towards influence and power and thus shifting the focus of the processes from the decision-making itself towards more...

  17. Hard photoproduction at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier / CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

    2007-07-01

    In view of possible photoproduction studies in ultra-peripheral heavy-ion collisions at the LHC, we briefly review the present theoretical understanding of photons and hard photoproduction processes at HERA, discussing the production of jets, light and heavy hadrons, quarkonia, and prompt photons. We address in particular the extraction of the strong coupling constant from photon structure function and inclusive jet measurements, the infrared safety and computing time of jet definitions, the sensitivity of di-jet cross sections on the parton densities in the photon, factorization breaking in diffractive di-jet production, the treatment of the heavy-quark mass in charm production, the relevance of the color-octet mechanism for quarkonium production, and isolation criteria for prompt photons. (author)

  18. Hydrogeological assumptions for flow modelling within fractured rocks

    Czech Academy of Sciences Publication Activity Database

    Hanzlík, Josef; Jahoda, Karel

    Praha : Ústav hydrogeologie a inženýrské geologie UK, 1994 - (Krásný, J.; Hrkal, Z.). s. 3-7 [Workshop on hard rock hydrogeology of the Bohemian massif. 03.10.1994-05.10.1994, Rohanov] R&D Projects: GA AV ČR IA34619

  19. Hungry for Rocks

    Science.gov (United States)

    2004-01-01

    This image from the Mars Exploration Rover Spirit hazard identification camera shows the rover's perspective just before its first post-egress drive on Mars. On Sunday, the 15th martian day, or sol, of Spirit's journey, engineers drove Spirit approximately 3 meters (10 feet) toward its first rock target, a football-sized, mountain-shaped rock called Adirondack (not pictured). In the foreground of this image are 'Sashimi' and 'Sushi' - two rocks that scientists considered investigating first. Ultimately, these rocks were not chosen because their rough and dusty surfaces are ill-suited for grinding.

  20. T-H-M couplings in rock. Overview of results of importance to the SR-Can safety assessment

    International Nuclear Information System (INIS)

    hydraulic significance of the Excavation Damaged Zone (EDZ) is assessed from experiences and observations made during different tunnelling projects at the Aespoe Hard Rock laboratory and from conclusions of topical overviews. Previously, the general view was that an EDZ would form an independent and fast pathway along the drift. This is recognized to be an oversimplification. Rather, the EDZ is more likely to be discontinuous. In addition, it will be possible to reduce the damage by applying improved drill and blast procedures. The impacts of heat generation and glacial load on the hydraulic conditions in the far-field are analyzed using results from large-scale DEC thermo-mechanical models and preliminary results from on-going simulations of the ice-crust-mantle interaction during the most recent glaciation. Spalling in the walls of deposition holes as a result of excavation is concluded to be unlikely at all sites, but almost certain to occur after a few years of heating in dry deposition holes where the bentonite buffer has not taken up sufficient amounts of water to establish any support pressure. There are many uncertainties. The most important one is probably that of the development of stresses and pore pressures at repository depth during a glacial cycle. The ice-crust-mantle interaction analyses used to calculate the stresses assumed in this report are based on an earth model that appears to be too simplistic for this particular purpose. New analyses, with more realistic earth models and with updated ice load data, are underway and will be used to revise the results given here. Also some of the stress-transmissivity relations are uncertain, in particular when it comes to estimating effects of deformations of large fractures. Other uncertainties, for instance in site data such as the magnitudes and orientations of in situ stresses and rock properties data, are large but not larger than corresponding differences between the different sites, and do not appear to be of

  1. T-H-M couplings in rock. Overview of results of importance to the SR-Can safety assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hoekmark, Harald; Faelth, Billy [Clay Technology AB, Lund (Sweden); Wallroth, Thomas [BERGAB, Goeteborg (Sweden)

    2006-09-15

    hydraulic significance of the Excavation Damaged Zone (EDZ) is assessed from experiences and observations made during different tunnelling projects at the Aespoe Hard Rock laboratory and from conclusions of topical overviews. Previously, the general view was that an EDZ would form an independent and fast pathway along the drift. This is recognized to be an oversimplification. Rather, the EDZ is more likely to be discontinuous. In addition, it will be possible to reduce the damage by applying improved drill and blast procedures. The impacts of heat generation and glacial load on the hydraulic conditions in the far-field are analyzed using results from large-scale DEC thermo-mechanical models and preliminary results from on-going simulations of the ice-crust-mantle interaction during the most recent glaciation. Spalling in the walls of deposition holes as a result of excavation is concluded to be unlikely at all sites, but almost certain to occur after a few years of heating in dry deposition holes where the bentonite buffer has not taken up sufficient amounts of water to establish any support pressure. There are many uncertainties. The most important one is probably that of the development of stresses and pore pressures at repository depth during a glacial cycle. The ice-crust-mantle interaction analyses used to calculate the stresses assumed in this report are based on an earth model that appears to be too simplistic for this particular purpose. New analyses, with more realistic earth models and with updated ice load data, are underway and will be used to revise the results given here. Also some of the stress-transmissivity relations are uncertain, in particular when it comes to estimating effects of deformations of large fractures. Other uncertainties, for instance in site data such as the magnitudes and orientations of in situ stresses and rock properties data, are large but not larger than corresponding differences between the different sites, and do not appear to be of

  2. Classification of fine-grained igneous, sedimentary and metamorphic rocks through structured programming

    OpenAIRE

    Orozco Centeno, Wendy Patricia; Branch Bedoya, Jhon Willian; JIMÉNEZ BUILES, JOVANI ALBERTO

    2015-01-01

    The study of rocks has become more important, because through the rocks analysis I can be obtained information that can be useful in a lot of fields from mining to construction, passing through many different action fields from materials to processes. In order to analyze the rocks is required a preliminary macroscopic examination of several samples from the field in which one is going to work. The objective of this study is to describe properties such as color, hardness, texture, etc. Then we...

  3. Comments on chevron bend specimen for determining fracture toughness of rock

    Institute of Scientific and Technical Information of China (English)

    孙宗颀; 陈枫; 徐纪成

    2001-01-01

    Based on a number of tests on different rocks, Suggested Methods for Determining the Fracture Toughness of Rock (SMs) was reviewed. The advantages of SMs are obvious, but some problems are also discovered. A serious one is that the nonlinear corrected fracture toughness of chevron bend specimens, KCCB, is less than the uncorrected one, KCB, for hard rock like granite, marble and others. The reason is discussed and the proposal is given.

  4. Streamlined hard beds formed by palaeo-ice streams: A review

    Science.gov (United States)

    Krabbendam, Maarten; Eyles, Nick; Putkinen, Niko; Bradwell, Tom; Arbelaez-Moreno, Lina

    2016-06-01

    Fast-flowing ice streams occur within modern ice sheets and also operated in Pleistocene ice sheets. The reconstruction of palaeo-ice streams normally relies on the mapping of mega-scale glacial lineations (MSGLs) and drumlins composed of soft sediment, mainly till. Analysis of new satellite imagery and digital terrain models, demonstrates the presence of large fields of kilometre-scale glacial lineations comprising rock drumlins, megagrooves and megaridges. In this paper we describe and analyse a number of such 'hard-bed' landform systems from the former Laurentide and British-Irish ice sheets, occurring in a variety of palaeo-ice stream settings. These are attributed to erosion of crystalline and sedimentary rock below fast flowing ice streams. Bedrock properties such as hardness, fracture spacing and bedding and their orientation with respect to ice flow have a profound effect on the occurrence and character of elongate rock bedforms. Elongate streamlined forms on hard crystalline rock, as on the Canadian Shield, only form under special circumstances; in contrast, sedimentary strata are highly susceptible to form streamlined hard beds, specifically if bedrock strike is parallel to ice flow. Large-scale elongate rock bedforms are erosional in origin, formed by preferentially focused abrasion or by lateral plucking, depending on bedrock type. Many palaeo-ice stream footprints previously mapped in the Laurentide Ice Sheet on the basis of soft-bed bedforms are shown to be significantly larger, extending up-ice across sedimentary strata and onto Precambrian crystalline rocks. Hard-bed streamlined forms further show that ice streaming does not necessitate a deformable bed, but can equally occur on smooth hard beds.

  5. Interaction of clay and concrete plugs - Plugging of 5 m deep hole KA1621G01 at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Lund (Sweden); Luleaa Technical Univ., Luleaa (Sweden); Ramqvist, Gunnar [Eltekno AB, Figeholm (Sweden)

    2011-11-15

    Sealing of deep boreholes in repository rock is planned to be made by installing dense smectite clay plugs where the rock is low-permeable and casting concrete where the holes intersect water-bearing fracture zones. Such zones have to be stabilized before sealing starts because fragments of rock can otherwise fall off and make it difficult to bring equipment for concrete casting and clay plug units down. These parts of the holes are filled with concrete and clay plugs are then inserted up to the nearest fracture zone where concrete is filled to the required level etc. The role of the concrete in the hole and in the closest part of the surrounding fracture zone is to provide stable parts that are sufficiently fine-porous to prevent clay particles from contacting clay plugs to migrate into the fractures and be lost by erosion. While the larger parts of long clay plugs are believed to stay largely intact chemically for hundreds of thousands of years, the parts adjacent to concrete plugs may undergo changes and so can the concrete plugs themselves. The objective of the presently reported project was to identify the detailed processes and quantify associated changes in physical properties by investigating samples of clay and concrete from a 2.5 m long plug of clay over which an equally long concrete plug had been cast and left to rest for 3 years. The outcome of the investigations was that significant chemically induced changes in mineralogy and physical performance had occurred within a few centimetres distance from the clay/concrete contact but that virtually no changes had taken place at larger distance. A comprehensive laboratory study including X-ray diffraction (XRD), X-ray fluorescence (XRF) and electron microscopy study (SEM and TEM) on the sample material was performed including also dual beam (combined ion and electron) microscopy. It was found that the clay had infiltrated the contacting concrete plug after filling of the borehole since clay was detected both