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Sample records for repository performance confirmation

  1. Repository performance confirmation

    International Nuclear Information System (INIS)

    Hansen, Francis D.

    2011-01-01

    Repository performance confirmation links the technical bases of repository science and societal acceptance. This paper explores the myriad aspects of what has been labeled performance confirmation in U.S. programs, which involves monitoring as a collection of distinct activities combining technical and social significance in radioactive waste management. This paper is divided into four parts: (1) A distinction is drawn between performance confirmation monitoring and other testing and monitoring objectives; (2) A case study illustrates confirmation activities integrated within a long-term testing and monitoring strategy for Yucca Mountain; (3) A case study reviews compliance monitoring developed and implemented for the Waste Isolation Pilot Plant; and (4) An approach for developing, evaluating and implementing the next generation of performance confirmation monitoring is presented. International interest in repository monitoring is exhibited by the European Commission Seventh Framework Programme 'Monitoring Developments for Safe Repository Operation and Staged Closure' (MoDeRn) Project. The MoDeRn partners are considering the role of monitoring in a phased approach to the geological disposal of radioactive waste. As repository plans advance in different countries, the need to consider monitoring strategies within a controlled framework has become more apparent. The MoDeRn project pulls together technical and societal experts to assimilate a common understanding of a process that could be followed to develop a monitoring program. A fundamental consideration is the differentiation of confirmation monitoring from the many other testing and monitoring activities. Recently, the license application for Yucca Mountain provided a case study including a technical process for meeting regulatory requirements to confirm repository performance as well as considerations related to the preservation of retrievability. The performance confirmation plan developed as part of the

  2. Impact of Drill and Blast Excavation on Repository Performance Confirmation

    International Nuclear Information System (INIS)

    Keller, R.; Francis, N.; Houseworth, J.; Kramer, N.

    2000-01-01

    There has been considerable work accomplished internationally examining the effects of drill and blast excavation on rock masses surrounding emplacement openings of proposed nuclear waste repositories. However, there has been limited discussion tying the previous work to performance confirmation models such as those proposed for Yucca Mountain, Nevada. This paper addresses a possible approach to joining the available information on drill and blast excavation and performance confirmation. The method for coupling rock damage data from drill and blast models to performance assessment models for fracture flow requires a correlation representing the functional relationship between the peak particle velocity (PPV) vibration levels and the potential properties that govern water flow rates in the host rock. Fracture aperture and frequency are the rock properties which may be most influenced by drill and blast induced vibration. If it can be shown (using an appropriate blasting model simulation) that the effect of blasting is far removed from the waste package in an emplacement drift, then disturbance to the host rock induced in the process of drill and blast excavation may be reasonably ignored in performance assessment calculations. This paper proposes that the CANMET (Canada Center for Mineral and Energy Technology) Criterion, based on properties that determine rock strength, may be used to define a minimum PPV. This PPV can be used to delineate the extent of blast induced damage. Initial applications have demonstrated that blasting models can successfully be coupled with this criterion to predict blast damage surrounding underground openings. The Exploratory Studies Facility at Yucca Mountain has used a blasting model to generate meaningful estimates of near-field vibration levels and damage envelopes correlating to data collected from pre-existing studies conducted. Further work is underway to expand this application over a statistical distribution of geologic

  3. Performance Confirmation Plan

    International Nuclear Information System (INIS)

    Lindner, E.N.

    2000-01-01

    As described, the purpose of the Performance Confirmation Plan is to specify monitoring, testing, and analysis activities for evaluating the accuracy and adequacy of the information used to determine that performance objectives for postclosure will be met. This plan defines a number of specific performance confirmation activities and associated test concepts in support of the MGR that will be implemented to fulfill this purpose. In doing so, the plan defines an approach to identify key factors and processes, predict performance, establish tolerances and test criteria, collect data (through monitoring, testing, and experiments), analyze these data, and recommend appropriate action. The process of defining which factors to address under performance confirmation incorporates input from several areas. In all cases, key performance confirmation factors are those factors which are: (1) important to safety, (2) measurable and predictable, and (3) relevant to the program (i.e., a factor that is affected by construction, emplacement, or is a time-dependent variable). For the present version of the plan, performance confirmation factors important to safety are identified using the principal factors from the RSS (CRWMS M and O 2000a) (which is derived from TSPA analyses) together with other available performance assessment analyses. With this basis, key performance confirmation factors have been identified, and test concepts and test descriptions have been developed in the plan. Other activities are also incorporated into the performance confirmation program outside of these key factors. Additional activities and tests have been incorporated when they are prescribed by requirements and regulations or are necessary to address data needs and model validation requirements relevant to postclosure safety. These other activities have been included with identified factors to construct the overall performance confirmation program

  4. Performance Confirmation Plan

    International Nuclear Information System (INIS)

    Lindner, E.N.

    2000-01-01

    As described, the purpose of the Performance Confirmation Plan is to specify monitoring, testing, and analysis activities for evaluating the accuracy and adequacy of the information used to determine that performance objectives for postclosure will be met. This plan defines a number of specific performance confirmation activities and associated test concepts in support of the MGR that will be implemented to fulfill this purpose. In doing so, the plan defines an approach to identify key factors and processes, predict performance, establish tolerances and test criteria, collect data (through monitoring, testing, and experiments), analyze these data, and recommend appropriate action. The process of defining which factors to address under performance confirmation incorporates input from several areas. In all cases, key performance confirmation factors are those factors which are: (1) important to safety, (2) measurable and predictable, and (3) relevant to the program (i.e., a factor that i s affected by construction, emplacement, or is a time-dependent variable). For the present version of the plan, performance confirmation factors important to safety are identified using the principal factors from the RSS (CRWMS M and O 2000a) (which is derived from TSPA analyses) together with other available performance assessment analyses. With this basis, key performance confirmation factors have been identified, and test concepts and test descriptions have been developed in the plan. Other activities are also incorporated into the performance confirmation program outside of these key factors. Additional activities and tests have been incorporated when they are prescribed by requirements and regulations or are necessary to address data needs and model validation requirements relevant to postclosure safety. These other activities have been included with identified factors to construct the overall performance confirmation program

  5. Performance Confirmation Data Acquisition System

    International Nuclear Information System (INIS)

    D.W. Markman

    2000-01-01

    The purpose of this analysis is to identify and analyze concepts for the acquisition of data in support of the Performance Confirmation (PC) program at the potential subsurface nuclear waste repository at Yucca Mountain. The scope and primary objectives of this analysis are to: (1) Review the criteria for design as presented in the Performance Confirmation Data Acquisition/Monitoring System Description Document, by way of the Input Transmittal, Performance Confirmation Input Criteria (CRWMS M and O 1999c). (2) Identify and describe existing and potential new trends in data acquisition system software and hardware that would support the PC plan. The data acquisition software and hardware will support the field instruments and equipment that will be installed for the observation and perimeter drift borehole monitoring, and in-situ monitoring within the emplacement drifts. The exhaust air monitoring requirements will be supported by a data communication network interface with the ventilation monitoring system database. (3) Identify the concepts and features that a data acquisition system should have in order to support the PC process and its activities. (4) Based on PC monitoring needs and available technologies, further develop concepts of a potential data acquisition system network in support of the PC program and the Site Recommendation and License Application

  6. Performance confirmation data acquisition system

    International Nuclear Information System (INIS)

    McAffee, D.A.; Raczka, N.T.

    1997-01-01

    As part of the Viability Assessment (VA) work, this QAP-3-9 document presents and evaluates a comprehensive set of viable concepts for collecting Performance Confirmation (PC) related data. The concepts include: monitoring subsurface repository air temperatures, humidity levels and gaseous emissions via the subsurface ventilation systems, and monitoring the repository geo-technical parameters and rock mass from bore-holes located along the perimeter main drifts and throughout a series of human-rated Observation Drifts to be located in a plane 25 meters above the plane of the emplacement drifts. A key element of this document is the development and analysis of a purposed multi-purpose Remote Inspection Gantry that would provide direct, real-time visual, thermal, and radiological monitoring of conditions inside operational emplacement drifts and close-up observations of in-situ Waste Packages. Preliminary finite-element analyses are presented that indicate the technological feasibility of operating an inspection gantry inside the operational emplacement drifts for short inspection missions lasting 2--3 hours. Overall reliability, availability, and maintainability of the PC data collection concepts are discussed. Preliminary concepts for PC data collection network are also provided

  7. Performance confirmation data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    McAffee, D.A.; Raczka, N.T. [Yucca Mountain Project, Las Vegas, NV (United States)

    1997-12-31

    As part of the Viability Assessment (VA) work, this QAP-3-9 document presents and evaluates a comprehensive set of viable concepts for collecting Performance Confirmation (PC) related data. The concepts include: monitoring subsurface repository air temperatures, humidity levels and gaseous emissions via the subsurface ventilation systems, and monitoring the repository geo-technical parameters and rock mass from bore-holes located along the perimeter main drifts and throughout a series of human-rated Observation Drifts to be located in a plane 25 meters above the plane of the emplacement drifts. A key element of this document is the development and analysis of a purposed multi-purpose Remote Inspection Gantry that would provide direct, real-time visual, thermal, and radiological monitoring of conditions inside operational emplacement drifts and close-up observations of in-situ Waste Packages. Preliminary finite-element analyses are presented that indicate the technological feasibility of operating an inspection gantry inside the operational emplacement drifts for short inspection missions lasting 2--3 hours. Overall reliability, availability, and maintainability of the PC data collection concepts are discussed. Preliminary concepts for PC data collection network are also provided.

  8. PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION

    International Nuclear Information System (INIS)

    N.T. Raczka

    2000-01-01

    The purpose of this document is to identify and analyze the types of in-situ instruments and methods that could be used in support of the data acquisition portion of the Performance Confirmation (PC) program at the potential nuclear waste repository at Yucca Mountain. The PC program will require geomechanical , geophysical, thermal, and hydrologic instrumentation of several kinds. This analysis is being prepared to document the technical issues associated with each type of measurement during the PC period. This analysis utilizes the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) as its starting point. The scope of this analysis is primarily on the period after the start of waste package emplacement and before permanent closure of the repository, a period lasting between 15 and 300 years after last package emplacement (Stroupe 2000, Attachment 1, p. 1). The primary objectives of this analysis are to: (1) Review the design criteria as presented in the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a). The scope of this analysis will be limited to the instrumentation related to parameters that require continuous monitoring of the conditions underground. (2) Preliminary identification and listing of the data requirements and parameters as related to the current repository layout in support of PC monitoring. (3) Preliminary identification of methods and instrumentation for the acquisition of the required data. Although the ''Performance Confirmation Input Criteria'' (CRWMS M andO 1999a) defines a broad range of data that must be obtained from a variety of methods, the focus of this analysis is on instrumentation related to the performance of the rock mass and the formation of water in the repository environment, that is obtainable from in-situ observation, testing, and monitoring

  9. Development of the Performance Confirmation Program at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    G.D. LeCain; D. Barr; D. Weaver; R. Snell; S.W. Goodin; F.D. Hansen

    2006-01-01

    The Yucca Mountain Performance Confirmation program consists of tests, monitoring activities, experiments, and analyses to evaluate the adequacy of assumptions, data, and analyses that form the basis of the conceptual and numerical models of flow and transport associated with a proposed radioactive waste repository at Yucca Mountain, Nevada. The Performance Confirmation program uses an eight-stage risk-informed, performance-based approach. Selection of the Performance Confirmation activities (a parameter and a test method) for inclusion in the Performance Confirmation program was done using a risk-informed performance-based decision analysis. The result of this analysis and review was a Performance Confirmation base portfolio that consists of 20 activities. The 20 Performance Confirmation activities include geologic, hydrologic, and construction/engineering testing. Several of the activities were initiated during site characterization and are ongoing. Others activities will commence during construction and/or post emplacement and will continue until repository closure

  10. Perspectives on radioactive waste repository monitoring. Confirmation, compliance, confidence building, and societal vigilance

    Energy Technology Data Exchange (ETDEWEB)

    Bergmans, Anne [Antwerp Univ. (Belgium). Research Group Society and Environment; Elam, Mark [Gothenburg Univ. (Sweden); Simmons, Peter [East Anglia Univ., Norwich (United Kingdom); Sundqvist, Goeran [Oslo Univ. (Norway)

    2012-12-15

    Monitoring is now widely seen as a necessary part of programmes for the geological disposal of radioactive waste. However, we find different perspectives on the nature and role of monitoring. Among technical experts it is viewed firstly as a matter of performance confirmation, a tool for validating the safety case underlying repository construction. Among concerned citizens we find a view of monitoring as enabling the critical scrutiny of safety, an instrument for acknowledging uncertainties and detecting emergent problems in a repository. After outlining differing views on questions of whether, why, what, where and for how long to monitor we discuss monitoring in light of constant vigilance as a technical and moral principle of nuclear safety. We suggest that ''how much monitoring'' and ''how should it be organised'' are societal questions and as such need to be broadly discussed.

  11. Modelling saline intrusion for repository performance assessment

    International Nuclear Information System (INIS)

    Jackson, C.P.

    1989-04-01

    UK Nirex Ltd are currently considering the possibility of disposal of radioactive waste by burial in deep underground repositories. The natural pathway for radionuclides from such a repository to return to Man's immediate environment (the biosphere) is via groundwater. Thus analyses of the groundwater flow in the neighbourhood of a possible repository, and consequent radionuclide transport form an important part of a performance assessment for a repository. Some of the areas in the UK that might be considered as possible locations for a repository are near the coast. If a repository is located in a coastal region seawater may intrude into the groundwater flow system. As seawater is denser than fresh water buoyancy forces acting on the intruding saline water may have significant effects on the groundwater flow system, and consequently on the time for radionuclides to return to the biosphere. Further, the chemistry of the repository near-field may be strongly influenced by the salinity of the groundwater. It is therefore important for Nirex to have a capability for reliably modelling saline intrusion to an appropriate degree of accuracy in order to make performance assessments for a repository in a coastal region. This report describes work undertaken in the Nirex Research programme to provide such a capability. (author)

  12. Performance assessment of Mochovce repository

    Energy Technology Data Exchange (ETDEWEB)

    Mrskova, A; Hanusik, V [Dept. of Accident Management and Risk Assessment, Vyskumny Ustav Jadrovych Elektrarni, Trnava (Slovakia)

    2000-07-01

    The near-surface disposal site at Mochovce is designed for low-level and intermediate level radioactive waste. It is a vault-type concrete structure housing the reinforced concrete containers as the final waste packages. This paper shortly presents the long-term safety analysis methods applied for the post-closure phase of the repository. The main aim of paper is description of the philosophy of analysis, development of the scenarios, their modeling and comparing of the results of normal evolution scenario, alternative scenario and intruders scenario for some radionuclides. (author)

  13. Performance assessment of Mochovce repository

    International Nuclear Information System (INIS)

    Mrskova, A.; Hanusik, V.

    2000-01-01

    The near-surface disposal site at Mochovce is designed for low-level and intermediate level radioactive waste. It is a vault-type concrete structure housing the reinforced concrete containers as the final waste packages. This paper shortly presents the long-term safety analysis methods applied for the post-closure phase of the repository. The main aim of paper is description of the philosophy of analysis, development of the scenarios, their modeling and comparing of the results of normal evolution scenario, alternative scenario and intruders scenario for some radionuclides. (author)

  14. Preclosure monitoring and performance confirmation at Yucca Mountain: Applicability of geophysical, geohydrological, and geochemical methods

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1989-06-01

    The present paper presents considerations on studies that would be required for preclosure monitoring and performance confirmation of a nuclear waste geologic repository in an unsaturated zone. The critical parameters that should be monitored are reviewed and two scales of measurement relevant to monitoring activities, room scale and repository scale, are taken as a framework for investigation. A number of monitoring methods based on geophysics, geohydrology, and geochemistry are briefly summarized for their potential usefulness for preclosure monitoring and performance confirmation of the geologic repository. Particular emphasis is given to measurement of the spatial distribution of parameters in contrast to single-point measurements of quantities. 12 refs., 1 fig., 1 tab

  15. Alternative measure for performance of HLW geologic repository

    International Nuclear Information System (INIS)

    Joonhang, Ahn; Chambre, P.L.

    2001-01-01

    A repository performance model that can show effects of canister multiplicity and repository configuration has been developed. Masses of a radionuclide in the repository and in the far field are proposed as performance measures. Canister multiplicity has significant effects on the release of long-lived radionuclides from the repository. As more canisters are included in the same water stream, the radionuclide concentration in the stream increases, but becomes independent of the number of canisters for sufficiently many canisters. Effects of reduction of radionuclide mass in the repository on the repository performance are clearly observed if the canister multiplicity is taken into account and the mass-based measures are applied. (author)

  16. Numerical modeling capabilities to predict repository performance

    International Nuclear Information System (INIS)

    1979-09-01

    This report presents a summary of current numerical modeling capabilities that are applicable to the design and performance evaluation of underground repositories for the storage of nuclear waste. The report includes codes that are available in-house, within Golder Associates and Lawrence Livermore Laboratories; as well as those that are generally available within the industry and universities. The first listing of programs are in-house codes in the subject areas of hydrology, solute transport, thermal and mechanical stress analysis, and structural geology. The second listing of programs are divided by subject into the following categories: site selection, structural geology, mine structural design, mine ventilation, hydrology, and mine design/construction/operation. These programs are not specifically designed for use in the design and evaluation of an underground repository for nuclear waste; but several or most of them may be so used

  17. Spent fuel performance in geologic repository environments

    International Nuclear Information System (INIS)

    Bradley, D.J.

    1985-10-01

    The performance assessment of the waste package is a current area of study in the United States program to develop a geologic repository for nuclear waste isolation. The waste package is presently envisioned as the waste form and its surrounding containers and possibly a packing material composed of crushed host rock or mixtures of that rock with clays. This waste package is tied to performance criteria set forth in recent legislation. It is the goal of the Civilian Radioactive Waste Management Program to obtain the necessary information on the waste package, in several geologic environments, to show that the waste package provides reasonable assurance of meeting established performance criteria. This paper discusses the United States program directed toward managing high-level radioactive waste, with emphasis on the current effort to define the behavior of irradiated spent fuel in repository groundwaters. Current studies are directed toward understanding the rate and nature (such as valence state, colloid form if any, solid phase controlling solubility) of radionuclide release from the spent fuel. Due to the strong interactive effect of radiation, thermal fields, and waste package components on this release, current spent fuel studies are being conducted primarily in the presence of waste package components over a wide range of potential environments

  18. The Use of Digital Repositories for Enhancing Teacher Pedagogical Performance

    Science.gov (United States)

    Cohen, Anat; Kalimi, Sharon; Nachmias, Rafi

    2013-01-01

    This research examines the usage of local learning material repositories at school, as well as related teachers' attitudes and training. The study investigates the use of these repositories for enhancing teacher performance and assesses whether the assimilation of the local repositories increases their usage of and contribution to by teachers. One…

  19. A Mountain-Scale Monitoring Network for Yucca Mountain Performance Confirmation

    International Nuclear Information System (INIS)

    Freifeld, Barry; Tsang, Yvonne

    2006-01-01

    Confirmation of the performance of Yucca Mountain is required by 10 CFR Part 63.131 to indicate, where practicable, that the natural system acts as a barrier, as intended. Hence, performance confirmation monitoring and testing would provide data for continued assessment during the pre-closure period. In general, to carry out testing at a relevant scale is always important, and in the case of performance confirmation, it is particularly important to be able to test at the scale of the repository. We view the large perturbation caused by construction of the repository at Yucca Mountain as a unique opportunity to study the large-scale behavior of the natural barrier system. Repository construction would necessarily introduce traced fluids and result in the creation of leachates. A program to monitor traced fluids and construction leachates permits evaluation of transport through the unsaturated zone and potentially downgradient through the saturated zone. A robust sampling and monitoring network for continuous measurement of important parameters, and for periodic collection of agrochemical samples, is proposed to observe thermo-hydrogeochemical changes near the repository horizon and down to the water table. The sampling and monitoring network can be used to provide data to (1) assess subsurface conditions encountered and changes in those conditions during construction and waste emplacement operations; and (2) for modeling to determine that the natural system is functioning as intended

  20. CLASSIFICATION OF THE MGR PERFORMANCE CONFIRMATION DATA ACQUISITION/MONITORING SYSTEM

    International Nuclear Information System (INIS)

    J.A. Ziegler

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) performance confirmation data acquisition/monitoring system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMF 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333PY ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  1. Performance Assessment Strategy Plan for the Geologic Repository Program

    International Nuclear Information System (INIS)

    1990-01-01

    Performance assessment is a major constituent of the program being conducted by the US Department of Energy (DOE) to develop a geologic repository. Performance assessment is the set of activities needed for quantitative evaluations to assess compliance with the performance requirements in the regulations for a geologic repository and to support the development of the repository. The strategy for these evaluations has been documented in the Performance Assessment Strategy Plan (DOE, 1989). The implementation of the performance assessment strategy is defined in this document. This paper discusses the scope and objectives of the implementation plan, the relationship of the plan to other program plans, summarizes the performance assessment areas and the integrated strategy of the performance assessment program. 1 fig., 3 tabs

  2. Reliable predictions of waste performance in a geologic repository

    International Nuclear Information System (INIS)

    Pigford, T.H.; Chambre, P.L.

    1985-08-01

    Establishing reliable estimates of long-term performance of a waste repository requires emphasis upon valid theories to predict performance. Predicting rates that radionuclides are released from waste packages cannot rest upon empirical extrapolations of laboratory leach data. Reliable predictions can be based on simple bounding theoretical models, such as solubility-limited bulk-flow, if the assumed parameters are reliably known or defensibly conservative. Wherever possible, performance analysis should proceed beyond simple bounding calculations to obtain more realistic - and usually more favorable - estimates of expected performance. Desire for greater realism must be balanced against increasing uncertainties in prediction and loss of reliability. Theoretical predictions of release rate based on mass-transfer analysis are bounding and the theory can be verified. Postulated repository analogues to simulate laboratory leach experiments introduce arbitrary and fictitious repository parameters and are shown not to agree with well-established theory. 34 refs., 3 figs., 2 tabs

  3. Performance assessment development for a LILW repository in Slovenia

    International Nuclear Information System (INIS)

    Zeleznik, N.; Mele, I.

    2001-01-01

    Simultaneously with the site selection process for a low and intermediate level radioactive waste (LILW) repository, the preliminary assessment of the influence of the specific disposal concept on the environment and on the population was developed. The performance assessment team, organized in 1997 by ARAO, prepared several basic studies in order to clarify the objectives of the performance and safety assessment (PA/SA) procedure. In 1999 also the first performance assessment of two safety cases (surface and underground) for generic site for a LILW repository was realized. In the year 2000 activities on PA/SA analyses continued. A systematic, generic list was prepared of all possible features, events and processes (FEP list) predictable for surface or underground LILW disposal in Slovenia. Recommended and selected were the most reliable scenarios with conceptual models for LILW disposal in normal and altered evolution conditions. New verification of the obtained results was done with more powerful and accurate models for the surface repository over an aquifer of lower water permeability and an underground repository in a plastic rock. The results for both generic cases under normal evolution scenarios showed that there is a negligible dose influence on members of the critical population due to the migration of radionuclides from the foreseen LILW repository. The results of the already performed work as well as plans for the future activities are presented in the paper.(author)

  4. Preliminary Analysis of Remote Monitoring and Robotic Concepts for Performance Confirmation

    International Nuclear Information System (INIS)

    McAffee, D.A.

    1997-01-01

    As defined in 10 CFR Part 60.2, Performance Confirmation is the ''program of tests, experiments and analyses which is conducted to evaluate the accuracy and adequacy of the information used to determine with reasonable assurance that the performance objectives for the period after permanent closure will be met''. The overall Performance Confirmation program begins during site characterization and continues up to repository closure. The main purpose of this document is to develop, explore and analyze initial concepts for using remotely operated and robotic systems in gathering repository performance information during Performance Confirmation. This analysis focuses primarily on possible Performance Confirmation related applications within the emplacement drifts after waste packages have been emplaced (post-emplacement) and before permanent closure of the repository (preclosure). This will be a period of time lasting approximately 100 years and basically coincides with the Caretaker phase of the project. This analysis also examines, to a lesser extent, some applications related to Caretaker operations. A previous report examined remote handling and robotic technologies that could be employed during the waste package emplacement phase of the project (Reference 5.1). This analysis is being prepared to provide an early investigation of possible design concepts and technical challenges associated with developing remote systems for monitoring and inspecting activities during Performance Confirmation. The writing of this analysis preceded formal development of Performance Confirmation functional requirements and program plans and therefore examines, in part, the fundamental Performance Confirmation monitoring needs and operating conditions. The scope and primary objectives of this analysis are to: (1) Describe the operating environment and conditions expected in the emplacement drifts during the preclosure period. (Presented in Section 7.2). (2) Identify and discuss the

  5. Workshop on rock mechanics issues in repository design and performance assessment

    International Nuclear Information System (INIS)

    1996-04-01

    The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ''Rock Mechanics Issues in Repository Design and Performance Assessment'' on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions

  6. SKI SITE-94, deep repository performance assessment project, summary

    International Nuclear Information System (INIS)

    1999-01-01

    SITE-94 is a comprehensive performance assessment exercise for a hypothetical repository for spent nuclear fuel at a real site in Sweden. SITE-94 was carried out to develop the capability and tools to enable Swedish Nuclear Power Inspectorate (SKI) to review fully the proposals for a deep repository which are expected to be made by the Swedish Nuclear Fuel and Waste Management Company, SKB (the implementor). Sweden is one of the leading countries in the research and development of geological disposal of radioactive waste. The developed methodology for performance assessment has attracted interests from other countries. The Summary of the main report of the SITE-94 project is translated here into Japanese to allow to make the information on the methodology and the related issues available among Japanese concerned. (author)

  7. Thermo-mechanical effects from a KBS-3 type repository. Performance of pillars between repository tunnels

    International Nuclear Information System (INIS)

    Hakami, E.; Olofsson, Stig-Olof

    2000-03-01

    The aim of this study has been to investigate how the rock mass, in the near field of a KBS-3 type repository, will be affected by the excavation of tunnels and deposition holes and the thermal load from the deposited waste. The three-dimensional finite difference program FLAC 3D was used to perform numerical simulation of the rock mass behaviour. The rock mass was modelled as a homogeneous and isotropic continuum. The initial area heat intensity of the repository was assumed to be 10 W/m 2 in all models. The results show that in the middle of the pillar between the repository tunnels the temperature reaches a maximum of about 70 deg C after 55 years of deposition. The extent of areas where the rock is predicted to yield depends on the assumed quality of the rock mass and the initial in-situ stress field. The volume of yielded rock reaches a maximum after about 200 years after deposition. For a rock mass with internal friction angle of 45 deg and cohesion of 5 MPa (using a Mohr-Coulomb material model), the extent of yielded rock is limited to about 1.5 m behind the excavation periphery. The largest rock displacements are found in the tunnel floor at the upper part of the deposition holes. Tension and shear failure in the periphery of the excavations is predicted to occur during the rock excavation, with a depth extension depending on the magnitude and orientation of the in-situ stresses, as well as on the rock mass quality. Both the excavation effects and the then-no-mechanical effects are smallest when the major principal stress is oriented parallel with the deposition tunnels. The maximum convergence between tunnel walls was calculated to occur after 200 years and be about 9 mm, in the model assuming a rock mass with 5 MPa cohesion, 45 deg internal friction angle and maximum horizontal stress perpendicular to the tunnel. In this study confining effects from the buffer and backfill material was neglected. The effective stress concept was used in most of the models

  8. Performance assessment plans and methods for the Salt Repository Project

    International Nuclear Information System (INIS)

    1984-08-01

    This document presents the preliminary plans and anticipated methods of the Salt Repository Project (SRP) for assessing the postclosure and radiological aspects of preclosure performance of a nuclear waste repository in salt. This plan is intended to be revised on an annual basis. The emphasis in this preliminary effort is on the method of conceptually dividing the system into three subsystems (the very near field, the near field, and the far field) and applying models to analyze the behavior of each subsystem and its individual components. The next revision will contain more detailed plans being developed as part of Site Characterization Plan (SCP) activities. After a brief system description, this plan presents the performance targets which have been established for nuclear waste repositories by regulatory agencies (Chapter 3). The SRP approach to modeling, including sensitivity and uncertainty techniques is then presented (Chapter 4). This is followed by a discussion of scenario analysis (Chapter 5), a presentation of preliminary data needs as anticipated by the SRP (Chapter 6), and a presentation of the SRP approach to postclosure assessment of the very near field, the near field, and the far field (Chapters 7, 8, and 9, respectively). Preclosure radiological assessment is discussed in Chapter 10. Chapter 11 presents the SRP approach to code verification and validation. Finally, the Appendix lists all computer codes anticipated for use in performance assessments. The list of codes will be updated as plans are revised

  9. Important parameters in the performance of a potential repository at Yucca Mountain (TSPA-1995)

    International Nuclear Information System (INIS)

    Atkins, J.E.; Sevougian, S.D.; Lee, J.H.; Andrews, R.W.; McNeish, J.A.

    1996-01-01

    A total system performance assessment (TSPA) was conducted to determine how a potential repository at Yucca Mountain would behave. Using the results of this TSPA, regression was done to determine which parameters had the most important effect on the repository performance. These results were consistent with the current conceptual understanding of the repository

  10. Some considerations for validation of repository performance assessment models

    International Nuclear Information System (INIS)

    Eisenberg, N.

    1991-01-01

    Validation is an important aspect of the regulatory uses of performance assessment. A substantial body of literature exists indicating the manner in which validation of models is usually pursued. Because performance models for a nuclear waste repository cannot be tested over the long time periods for which the model must make predictions, the usual avenue for model validation is precluded. Further impediments to model validation include a lack of fundamental scientific theory to describe important aspects of repository performance and an inability to easily deduce the complex, intricate structures characteristic of a natural system. A successful strategy for validation must attempt to resolve these difficulties in a direct fashion. Although some procedural aspects will be important, the main reliance of validation should be on scientific substance and logical rigor. The level of validation needed will be mandated, in part, by the uses to which these models are put, rather than by the ideal of validation of a scientific theory. Because of the importance of the validation of performance assessment models, the NRC staff has engaged in a program of research and international cooperation to seek progress in this important area. 2 figs., 16 refs

  11. Performance Assessments of Generic Nuclear Waste Repositories in Shale

    Science.gov (United States)

    Stein, E. R.; Sevougian, S. D.; Mariner, P. E.; Hammond, G. E.; Frederick, J.

    2017-12-01

    Simulations of deep geologic disposal of nuclear waste in a generic shale formation showcase Geologic Disposal Safety Assessment (GDSA) Framework, a toolkit for repository performance assessment (PA) whose capabilities include domain discretization (Cubit), multiphysics simulations (PFLOTRAN), uncertainty and sensitivity analysis (Dakota), and visualization (Paraview). GDSA Framework is used to conduct PAs of two generic repositories in shale. The first considers the disposal of 22,000 metric tons heavy metal of commercial spent nuclear fuel. The second considers disposal of defense-related spent nuclear fuel and high level waste. Each PA accounts for the thermal load and radionuclide inventory of applicable waste types, components of the engineered barrier system, and components of the natural barrier system including the host rock shale and underlying and overlying stratigraphic units. Model domains are half-symmetry, gridded with Cubit, and contain between 7 and 22 million grid cells. Grid refinement captures the detail of individual waste packages, emplacement drifts, access drifts, and shafts. Simulations are run in a high performance computing environment on as many as 2048 processes. Equations describing coupled heat and fluid flow and reactive transport are solved with PFLOTRAN, an open-source, massively parallel multiphase flow and reactive transport code. Additional simulated processes include waste package degradation, waste form dissolution, radioactive decay and ingrowth, sorption, solubility, advection, dispersion, and diffusion. Simulations are run to 106 y, and radionuclide concentrations are observed within aquifers at a point approximately 5 km downgradient of the repository. Dakota is used to sample likely ranges of input parameters including waste form and waste package degradation rates and properties of engineered and natural materials to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia National

  12. Repository seal materials performance for a SALT Repository Project 5-year code/model development plan: Draft

    International Nuclear Information System (INIS)

    1987-06-01

    This document describes an integrated laboratory testing and model development effort for the seal system for a high-level nuclear waste repository in salt. The testing and modeling efforts are designed to determine seal material response in the repository environment, to provide models of seal system components for performance assessment, and to assist in the development of seal system designs. A code/model development and performance analysis program will be performed to predict the short- and long-term response of seal materials and seal components. The results from these analyses will be used to support the material testing activities on this contract and to support performance assessment activities that are conducted in other parts of the Salt Repository Project (SRP). 48 refs., 15 figs., 4 tabs

  13. SKI SITE-94. Deep Repository Performance Assessment Project. Summary

    International Nuclear Information System (INIS)

    1997-02-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is neither a safety assessment nor a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The main report (SKI-R--96-36) gives a detailed description of the many inter-related studies undertaken as part of the research project, while the present report presents a condensed summary of the main report. 46 refs

  14. Confirming the Value of Swimming-Performance Models for Adolescents.

    Science.gov (United States)

    Dormehl, Shilo J; Robertson, Samuel J; Barker, Alan R; Williams, Craig A

    2017-10-01

    To evaluate the efficacy of existing performance models to assess the progression of male and female adolescent swimmers through a quantitative and qualitative mixed-methods approach. Fourteen published models were tested using retrospective data from an independent sample of Dutch junior national-level swimmers from when they were 12-18 y of age (n = 13). The degree of association by Pearson correlations was compared between the calculated differences from the models and quadratic functions derived from the Dutch junior national qualifying times. Swimmers were grouped based on their differences from the models and compared with their swimming histories that were extracted from questionnaires and follow-up interviews. Correlations of the deviations from both the models and quadratic functions derived from the Dutch qualifying times were all significant except for the 100-m breaststroke and butterfly and the 200-m freestyle for females (P motivation appeared to be synonymous with higher-level career performance. This mixed-methods approach helped confirm the validity of the models that were found to be applicable to adolescent swimmers at all levels, allowing coaches to track performance and set goals. The value of the models in being able to account for the expected performance gains during adolescence enables quantification of peripheral factors that could affect performance.

  15. Workshop on rock mechanics issues in repository design and performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ``Rock Mechanics Issues in Repository Design and Performance Assessment`` on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions. Selected papers have been indexed separately for inclusion the Energy Science and Technology Database.

  16. Sorption data base for performance assessment of radwaste repository

    International Nuclear Information System (INIS)

    Cho, Y.H.; Jung, J.; Lee, J.K.; Hahn, P.S.

    2001-01-01

    Sorption data base (SDB) provides readily available data for the performance assessment of radwaste repository when site-specific data are not available and/or more reference data are needed. The software developed in the Korea Atomic Energy Research Institute (KAERI), SDB-21C, is a graphic user interface (GUI) program that provides efficient and user friendly tools for evaluating the large amount of sorption data. The data base of distribution coefficients compiled in the program contains about 11,000 Nuclear Energy Agency (NEA) data and 2,000 KAERI data up to now while the addition of new data is under progress. Furthermore, the parametric model and its compiled data sets are also included in SDB-21C. (author)

  17. Validation of geotechnical software for repository performance assessment

    International Nuclear Information System (INIS)

    LeGore, T.; Hoover, J.D.; Khaleel, R.; Thornton, E.C.; Anantatmula, R.P.; Lanigan, D.C.

    1989-01-01

    An important step in the characterization of a high level nuclear waste repository is to demonstrate that geotechnical software, used in performance assessment, correctly models validation. There is another type of validation, called software validation. It is based on meeting the requirements of specifications documents (e.g. IEEE specifications) and does not directly address the correctness of the specifications. The process of comparing physical experimental results with the predicted results should incorporate an objective measure of the level of confidence regarding correctness. This paper reports on a methodology developed that allows the experimental uncertainties to be explicitly included in the comparison process. The methodology also allows objective confidence levels to be associated with the software. In the event of a poor comparison, the method also lays the foundation for improving the software

  18. Confirmation test on confinement performance of improved glove box

    International Nuclear Information System (INIS)

    Miura, S.; Kanazawa, J.; Nakajima, M.; Sakuno, K.; Miyata, H.

    1995-01-01

    Glove boxes are used at nuclear facilities to confine radioactive materials by ensuring a high level of airtightness and negative internal pressure. The allowable rate of air leakage is 0.1% vol/hr or less at the pre-service inspection. The negative pressure value is normally maintained at about -30 mm H 2 O. Structural strength and confinement reliability of glove boxes during earthquake are major concerns, and most important glove boxes are designed to withstand seismic class A events is Japan. This paper describes vibration tests done to confirm that improve large-sized glove boxes maintain their confinement performance and structural strength even during earthquake and that the design analysis methods used are appropriate. (author). 1 ref., 6 figs., 3 tabs

  19. Cryptonite: A Secure and Performant Data Repository on Public Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Kumbhare, Alok; Simmhan, Yogesh; Prasanna, Viktor

    2012-06-29

    Cloud storage has become immensely popular for maintaining synchronized copies of files and for sharing documents with collaborators. However, there is heightened concern about the security and privacy of Cloud-hosted data due to the shared infrastructure model and an implicit trust in the service providers. Emerging needs of secure data storage and sharing for domains like Smart Power Grids, which deal with sensitive consumer data, require the persistence and availability of Cloud storage but with client-controlled security and encryption, low key management overhead, and minimal performance costs. Cryptonite is a secure Cloud storage repository that addresses these requirements using a StrongBox model for shared key management.We describe the Cryptonite service and desktop client, discuss performance optimizations, and provide an empirical analysis of the improvements. Our experiments shows that Cryptonite clients achieve a 40% improvement in file upload bandwidth over plaintext storage using the Azure Storage Client API despite the added security benefits, while our file download performance is 5 times faster than the baseline for files greater than 100MB.

  20. Parametric study of geohydrologic performance characteristics for geologic waste repositories

    International Nuclear Information System (INIS)

    Bailey, C.E.; Marine, I.W.

    1980-11-01

    One of the major objectives of the National Waste Terminal Storage Program is to identify potential geologic sites for storage and isolation of radioactive waste (and possibly irradiated fuel). Potential sites for the storage and isolation of radioactive waste or spent fuel in a geologic rock unit are being carefully evaluated to ensure that radionuclides from the stored waste or fuel will never appear in the biosphere in amounts that would constitute a hazard to the health and safety of the public. The objective of this report is to quantify and present in graphical form the effects of significant geohydrologic and other performance characteristics that would influence the movement of radionuclides from a storage site in a rock unit to the biosphere. The effort in this study was focused on transport by groundwater because that is the most likely method of radionuclide escape. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater are presented. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere. These major performance characteristics are combind with each other and with the results of certain other combinations and presented in graphical form to provide the interrelationships of values measured during field studies. The graphical form of presentation should be useful in the screening process of site selection. An appendix illustrates the use of these graphs to assess the suitability of a site

  1. Approach to geologic repository post closure system performance assessment

    International Nuclear Information System (INIS)

    Pahwa, S.B.; Felton, W.; Duguid, J.O.

    1992-01-01

    An essential part of the license application for a geologic repository will be the demonstration of compliance with the standards set by the Environmental Protection Agency. The performance assessments that produce the demonstration must rely on models of various levels of detail. The most detailed of these models are needed for understanding thoroughly the complex physical and chemical processes affecting the behavior of the system. For studying the behavior of major components of the system, less detailed models are often useful. For predicting the behavior of the total system, models of a third kind may be needed. These models must cover all the important processes that contribute to the behavior of the system, because they must estimate the behavior under all significant conditions for 10,000 years. In addition, however, computer codes that embody these models must calculate very rapidly because of the EPA standard's requirement for probabilistic estimates, which will be produced by sampling thousands of times from probability distributions of parameters. For this reason, the total-system models must be less complex than the detailed-process and subsystem models. The total-system performance is evaluated through modeling of the following components: Radionuclide release from the engineered-barrier system. Fluid flow in the geologic units. Radionuclide transport to the accessible environment. Radionuclide release to the accessible environment and dose to man

  2. Performance analysis of conceptual waste package designs in salt repositories

    International Nuclear Information System (INIS)

    Jansen, G. Jr.; Raines, G.E.; Kircher, J.F.

    1984-01-01

    A performance analysis of commercial high-level waste and spent fuel conceptual package designs in reference repositories in three salt formations was conducted with the WAPPA waste package code. Expected conditions for temperature, stress, brine composition, radiation level, and brine flow rate were used as boundary conditions to compute expected corrosion of a thick-walled overpack of 1025 wrought steel. In all salt formations corrosion by low Mg salt-dissolution brines typical of intrusion scenarios was too slow to cause the package to fail for thousands of years after burial. In high Mg brines judged typical of thermally migrating brines in bedded salt formations, corrosion rates which would otherwise have caused the packages to fail within a few hundred years were limited by brine availability. All of the brine reaching the package was consumed by reaction with the iron in the overpack, thus preventing further corrosion. Uniform brine distribution over the package surface was an important factor in predicting long package lifetimes for the high Mg brines. 14 references, 15 figures

  3. A performance goal-based seismic design philosophy for waste repository facilities

    International Nuclear Information System (INIS)

    Hossain, Q.A.

    1994-02-01

    A performance goal-based seismic design philosophy, compatible with DOE's present natural phenomena hazards mitigation and ''graded approach'' philosophy, has been proposed for high level nuclear waste repository facilities. The rationale, evolution, and the desirable features of this method have been described. Why and how the method should and can be applied to the design of a repository facility are also discussed

  4. 10 CFR 60.112 - Overall system performance objective for the geologic repository after permanent closure.

    Science.gov (United States)

    2010-01-01

    ... repository after permanent closure. 60.112 Section 60.112 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Performance... environment following permanent closure conform to such generally applicable environmental standards for...

  5. Review of Y/OWI/TM-36: repository design performance in salt, granite, shale or basalt

    International Nuclear Information System (INIS)

    Talbot, R.; Nair, O.B.

    1979-09-01

    As part of the ongoing work by the Lawrence Livermore Laboratory to evaluate repository design performance, this memorandum presents a review of the preconceptual repository design described in Y/OWI/TM-36, Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, April 1978. The purpose of this review is: to assess the adequacy of the design procedures and assumptions; to identify inappropriate or unsubstantiated design issues; to identify areas where additional numerical analyses may be required; and to develop data for inclusion in a reference repository design. The preconceptual repository design is presented in the form of 23 volumes of data base, analyses, and design layouts for four rock types: bedded salt, shale, granite and basalt. This memorandum reviews all four repository designs

  6. Analysis of spent fuel performance in a geologic repository

    International Nuclear Information System (INIS)

    Apted, M.J.; Liebetrau, A.M.; Engel, D.W.; Alexander, D.H.

    1986-04-01

    The Analytical REpository Source-Term (AREST) code developed for the US Department of Energy is being used to assess the time-dependent release rate of radionuclides from spent nuclear fuel disposed in geologic repositories. The Waste Package Release (WPR) submodule of AREST calculates the release from individual waste packages containing spent fuel based on site-specific design, solubility, corrosion, sorption, and mass transfer data. Under the open system conditions of a repository, there are two limiting release mechanisms: surface reaction control and transport control. In addition, a separate release case is defined for soluble radionuclides that are inventory limited. Mass transfer equations for each of these processes are incorporated into AREST. Four separate sources are identified in the AREST code based on inventory and release mechanism: UO 2 matrix (transport limited), gap (inventory limited), grain boundary (inventory limited, combined with gap), and cladding (transport limited). The calculated release of nuclides contained in the matrix (> 90% of the entire inventory) is controlled by UO 2 solubility or the solubility of a nuclide-bearing phase, whichever is lower

  7. Performance confirmation operation of water environment control facility

    International Nuclear Information System (INIS)

    Magome, Hirokatsu; Okada, Yuji; Tomita, Kenji; Iida, Kazuhiro; Ando, Hitoshi; Yonekawa, Akihisa; Ueda, Haruyasu; Hanawa, Hiroshi; Kanno, Masaru; Sakuta, Yoshiyuki

    2015-09-01

    In Japan Atomic Energy Agency, in order to solve the problem in the long-term operation of a light water reactor, preparation which does the irradiation experiment of light-water reactor fuel and material was advanced. JMTR stopped after the 165th operation cycle in August 2006, and is advancing renewal of the irradiation facility towards re-operation. The material irradiation test facility was installed from 2008 fiscal year to 2012 fiscal year in JMTR. The material irradiation test facility is used for IASCC study, and consists of mainly three equipments. This report described performance operating test of the water environmental control facilities for IASCC study carried out 2013 fiscal year. (author)

  8. Microbial Influence on the Performance of Subsurface, Salt-Based Radioactive Waste Repositories. An Evaluation Based on Microbial Ecology, Bioenergetics and Projected Repository Conditions

    International Nuclear Information System (INIS)

    Swanson, J.S.; Reed, D.T.; Cherkouk, A.; Arnold, T.; Meleshyn, A.; Patterson, Russ

    2018-01-01

    For the past several decades, the Nuclear Energy Agency Salt Club has been supporting and overseeing the characterisation of rock salt as a potential host rock for deep geological repositories. This extensive evaluation of deep geological settings is aimed at determining - through a multidisciplinary approach - whether specific sites are suitable for radioactive waste disposal. Studying the microbiology of granite, basalt, tuff, and clay formations in both Europe and the United States has been an important part of this investigation, and much has been learnt about the potential influence of microorganisms on repository performance, as well as about deep subsurface microbiology in general. Some uncertainty remains, however, around the effects of microorganisms on salt-based repository performance. Using available information on the microbial ecology of hyper-saline environments, the bioenergetics of survival under high ionic strength conditions and studies related to repository microbiology, this report summarises the potential role of microorganisms in salt-based radioactive waste repositories

  9. Application of systems engineering to determine performance requirements for repository waste packages

    International Nuclear Information System (INIS)

    Aitken, E.A.; Stimmell, G.L.

    1987-01-01

    The waste package for a nuclear waste repository in salt must contribute substantially to the performance objectives defined by the Salt Repository Project (SRP) general requirements document governing disposal of high-level waste. The waste package is one of the engineered barriers providing containment. In establishing the performance requirements for a project focused on design and fabrication of the waste package, the systems engineering methodology has been used to translate the hierarchy requirements for the repository system to specific performance requirements for design and fabrication of the waste package, a subsystem of the repository. This activity is ongoing and requires a methodology that provides traceability and is capable of iteration as baseline requirements are refined or changed. The purpose of this summary is to describe the methodology being used and the way it can be applied to similar activities in the nuclear industry

  10. A performance goal-based seismic design philosophy for waste repository facilities

    International Nuclear Information System (INIS)

    Hossain, Q.A.

    1994-01-01

    A performance goal-based seismic design philosophy, compatible with DOE's present natural phenomena hazards mitigation and open-quotes graded approachclose quotes philosophy, has been proposed for high level nuclear waste repository facilities. The rationale, evolution, and the desirable features of this method have been described. Why and how the method should and can be applied to the design of a repository facility are also discussed

  11. Performance analysis of a repository for low and intermediate level reactor waste

    International Nuclear Information System (INIS)

    Vieno, T.; Nordman, H.; Vuori, S.; Peltonen, E.

    1987-01-01

    In Finland, utilities producing nuclear energy are responsible for the management of the radioactive waste, including final disposal. As regards low and intermediate level waste, the approach has been adopted to employ the power plant sites for locations of repositories. The repositories will be excavated at the depth of about 50 to 125 m in the bedrock of the two Finnish nuclear power plant sites, Loviisa and Olkiluoto. The performance analysis presented in this paper has been carried out for the Preliminary Safety Analysis Report (PSAR) of the Olkiluoto repository. A flexible model has been developed to estimate the release of radionuclides from waste packages and their subsequent transport through the engineered barriers in the repository. Gradual degradation of the engineered barriers is accounted for by altering parameters at fixed time points. Safety margins of the disposal concept have been evaluated by including disturbed evolution scenarios in the analysis. 13 references, 10 figures, 2 tables

  12. Draft Technical Position Subtask 1.1: waste package performance after repository closure. Volume 1

    International Nuclear Information System (INIS)

    Davis, M.S.; Schweitzer, D.G.

    1983-08-01

    This document provides guidance to the DOE on the issues and information necessary for the NRC to evaluate waste package performance after repository closure. Minimal performance objectives of the waste package are required by proposed 10 CFR 60. This Draft Technical Position describes the various options available to the DOE for compliance and discusses advantages and disadvantages of various choices. Examples are discussed dealing with demonstrability, predictability and reasonable assurance. The types of performance are considered. The document summarizes presently identified high priority issues needed to evaluate waste package performance after repository closure. 20 references, 7 tables

  13. Development of an object-oriented simulation code for repository performance assessment

    International Nuclear Information System (INIS)

    Tsujimoto, Keiichi; Ahn, J.

    1999-01-01

    As understanding for mechanisms of radioactivity confinement by a deep geologic repository improves at the individual process level, it has become imperative to evaluate consequences of individual processes to the performance of the whole repository system. For this goal, the authors have developed a model for radionuclide transport in, and release from, the repository region by incorporating multiple-member decay chains and multiple waste canisters. A computer code has been developed with C++, an object-oriented language. By utilizing the feature that a geologic repository consists of thousands of objects of the same kind, such as the waste canister, the repository region is divided into multiple compartments and objects for simulation of radionuclide transport. Massive computational tasks are distributed over, and executed by, multiple networked workstations, with the help of parallel virtual machine (PVM) technology. Temporal change of the mass distribution of 28 radionuclides in the repository region for the time period of 100 million yr has been successfully obtained by the code

  14. Some concepts of model uncertainty for performance assessments of nuclear waste repositories

    International Nuclear Information System (INIS)

    Eisenberg, N.A.; Sagar, B.; Wittmeyer, G.W.

    1994-01-01

    Models of the performance of nuclear waste repositories will be central to making regulatory decisions regarding the safety of such facilities. The conceptual model of repository performance is represented by mathematical relationships, which are usually implemented as one or more computer codes. A geologic system may allow many conceptual models, which are consistent with the observations. These conceptual models may or may not have the same mathematical representation. Experiences in modeling the performance of a waste repository representation. Experiences in modeling the performance of a waste repository (which is, in part, a geologic system), show that this non-uniqueness of conceptual models is a significant source of model uncertainty. At the same time, each conceptual model has its own set of parameters and usually, it is not be possible to completely separate model uncertainty from parameter uncertainty for the repository system. Issues related to the origin of model uncertainty, its relation to parameter uncertainty, and its incorporation in safety assessments are discussed from a broad regulatory perspective. An extended example in which these issues are explored numerically is also provided

  15. Performance assessment for Nuclear Power Plant Krsko intermediate and low-level rad-waste repository

    International Nuclear Information System (INIS)

    Jelavic, V.; Skanata, D.; Plecjas, I.

    1990-01-01

    Performance safety Assessment for NPP Krsko radwaste repository was performed (LLW/ILW). Shallow land and tunnel type concept were analyzed. Because it was based on two unknown referent sites, one for the shallow land concept and the other for the tunnel type, analysis was generic in nature. Scenario selecting process and consequence analysis were performed by using deterministic approach. Results for both concepts of disposal suggests that proposed NPP Krsko radwaste repository reference site and disposal technology will fully meet radiation limits imposed by the Yugoslav regulations and ICRP guidelines. (author)

  16. Methods of calculating the post-closure performance of high-level waste repositories

    International Nuclear Information System (INIS)

    Ross, B.

    1989-02-01

    This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs

  17. Methods of calculating the post-closure performance of high-level waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Ross, B. (ed.)

    1989-02-01

    This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs.

  18. Scientific basis for long-term prediction of waste-form performance under repository conditions

    International Nuclear Information System (INIS)

    Mendel, J.E.

    1982-10-01

    This paper presents an overview of the fundamental principles involved in predicting long-term performance of waste forms by the as-low-as-reasonably-achievable approach. Repository conditions which make up the waste-form environment, the aging of the waste form, the important radionuclides in the waste form, the chemistry of repository fluids, and multicomponent interactions testing were considered in order to describe these principles. The need for confidence limits on the prediction of waste-form performance and ways of achieving a definition of the confidence limits are discussed

  19. Demonstration of a repository performance assessment capability at the US Nuclear Regulatory Commission

    International Nuclear Information System (INIS)

    Codell, R.; Eisenberg, N.; McCartin, T.; Park, J.

    1991-01-01

    In order to better review licensing submittals for a High-Level Waste Repository, the US Nuclear Regulatory Commission staff has expanded and improved its capability to conduct performance assessments. A demonstration of this capability used the limited data from Yucca Mountain, Nevada to investigate a small set of scenario classes. Models of release and transport of radionuclides from a repository via the groundwater and direct release pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year simulation time. Latin hypercube sampling of input parameters was used to express results as distributions and to investigate model sensitivities. This methodology demonstration should not be interpreted as an estimate of performance of the proposed repository at Yucca Mountain, Nevada

  20. Advances in the study of far-field phenomena affecting repository performance

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1991-01-01

    Studies of far-field phenomena affecting repository performance have focussed on the role of fractures and other heterogeneities in the potential transport of radioactive solutes from the repository to the biosphere. The present paper summarizes two recent advances in the subject: the channeling model for the understanding and analysis tracer transport in variable-aperture fractures and the modeling of coupled thermo-hydro-mechanical processes in geologic formation around a repository. The paper concludes with remarks on the need for duality in the approach to performance assessment. One line of the duality is fundamental studies and the other, goal-oriented assessment to satisfy regulatory requirements. 15 refs., 10 figs., 1 tab

  1. A performance assessment review tool for the proposed radioactive waste repository at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    Mohanty, Sitakanta; Codell, Richard

    2000-01-01

    The U.S. Nuclear Regulatory Commission (NRC), with the assistance of the Center for Nuclear Waste Regulatory Analyses, has developed a Total-system Performance Assessment (TPA) Code to assist in evaluating the performance of the Yucca Mountain (YM) High-Level Waste Repository in Nevada, proposed by the U.S. Department of Energy (DOE). The proposed YM repository would be built in a thick sequence of partially saturated volcanic tuff above the water table. Among the unique challenges of this environment are (1) the transport of radionuclides would take place partially through highly heterogeneous unsaturated rock; (2) the waste packages (WPs) would be generally exposed to oxidizing conditions, and (3) water either infiltrating from the surface or recirculating because of decay heat may drip onto the WPs. Tools such as the TPA code and embedded techniques for evaluating YM performance are aimed at (1) determining the parameters and key parts of the repository system that have the most influence on repository performance; (2) performing alternative conceptual models studies, especially with bounding models; (3) estimating the relative importance of the physical phenomena that lead to human exposure to radionuclides; and (4) improving NRC staff capabilities in performance assessment and associated license application reviews. This paper presents an overview of the NRC conceptual framework, approach to conducting system-level sensitivity analyses for determining influential parameters, and alternative conceptual model studies to investigate the effect of model uncertainties. (author)

  2. NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-07-01

    This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules.

  3. NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

    International Nuclear Information System (INIS)

    1982-07-01

    This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules

  4. Role of groundwater oxidation potential and radiolysis on waste glass performance in crystalline repository environments

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.

    1985-01-01

    Laboratory experiments have shown that groundwater conditions in a Stripa granite repository will be as reducing as those in a basalt repository. The final oxidation potential (Eh) at 70 0 C for Stripa groundwater deaerated and equilibrated with crystalline granite was -0.45V. In contrast, the oxidation potential at 60 0 C for Grande Ronde groundwater equilibrated with basalt was -0.40V. The reducing groundwater conditions were found to slightly decrease the time-dependent release of soluble components from the waste glass. Spectrophotometric analysis of the equilibrated groundwaters indicated the presence of Fe 2+ confirming that the Fe 2+ /Fe 3+ couple is controlling the oxidation potential. It was also shown that in the alkaline pH regime of these groundwaters the iron species are primarily associated with x-ray amorphous precipitates in the groundwater. Gamma radiolysis in the absence of waste glass and in the absence of oxygen further reduces the oxidation potential of both granitic and basaltic groundwaters. The effect is more pronounced in the basaltic groundwater. The mechanism for this decrease is under investigation but appears related to the reactive amorphous precipitate. The results of these tests suggest that H 2 may not escape from the repository system as postulated and that radiolysis may not cause the groundwaters to become oxidizing in a crystalline repository when abundant Fe 2+ species are present. 23 refs., 3 figs., 3 tabs

  5. Site specificity of biosphere parameter values in performance assessments of near-surface repositories

    International Nuclear Information System (INIS)

    Zeevaert, Th.; Volckaert, G.; Vandecasleele

    1993-01-01

    The contribution is dealing with the performance assessment model for near surface repositories in Belgium. It consists of four submodels called: site, aquifer, biosphere and dose. For some characteristic radionuclides, results of the study are shown for a typical site, and differences in doses assessed with the generic approach discussed. Shortcomings are indicated

  6. Performance of high level waste forms and engineered barriers under repository conditions

    International Nuclear Information System (INIS)

    1991-02-01

    The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

  7. The Microbiology of Subsurface, Salt-Based Nuclear Waste Repositories: Using Microbial Ecology, Bioenergetics, and Projected Conditions to Help Predict Microbial Effects on Repository Performance

    International Nuclear Information System (INIS)

    Swanson, Juliet S.; Cherkouk, Andrea; Arnold, Thuro; Meleshyn, Artur; Reed, Donald T.

    2016-01-01

    This report summarizes the potential role of microorganisms in salt-based nuclear waste repositories using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions, and ''repository microbiology'' related studies. In areas where microbial activity is in question, there may be a need to shift the research focus toward feasibility studies rather than studies that generate actual input for performance assessments. In areas where activity is not necessary to affect performance (e.g., biocolloid transport), repository-relevant data should be generated. Both approaches will lend a realistic perspective to a safety case/performance scenario that will most likely underscore the conservative value of that case.

  8. The Microbiology of Subsurface, Salt-Based Nuclear Waste Repositories: Using Microbial Ecology, Bioenergetics, and Projected Conditions to Help Predict Microbial Effects on Repository Performance

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Juliet S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf, Rossendorf (Germany); Arnold, Thuro [Helmholtz-Zentrum Dresden-Rossendorf, Rossendorf (Germany); Meleshyn, Artur [Gesellschaft fur Anlagen und Reaktorsicherheit, Braunschweig (Germany); Reed, Donald T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-17

    This report summarizes the potential role of microorganisms in salt-based nuclear waste repositories using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions, and “repository microbiology” related studies. In areas where microbial activity is in question, there may be a need to shift the research focus toward feasibility studies rather than studies that generate actual input for performance assessments. In areas where activity is not necessary to affect performance (e.g., biocolloid transport), repository-relevant data should be generated. Both approaches will lend a realistic perspective to a safety case/performance scenario that will most likely underscore the conservative value of that case.

  9. Improved metamodel-based importance sampling for the performance assessment of radioactive waste repositories

    International Nuclear Information System (INIS)

    Cadini, F.; Gioletta, A.; Zio, E.

    2015-01-01

    In the context of a probabilistic performance assessment of a radioactive waste repository, the estimation of the probability of exceeding the dose threshold set by a regulatory body is a fundamental task. This may become difficult when the probabilities involved are very small, since the classically used sampling-based Monte Carlo methods may become computationally impractical. This issue is further complicated by the fact that the computer codes typically adopted in this context requires large computational efforts, both in terms of time and memory. This work proposes an original use of a Monte Carlo-based algorithm for (small) failure probability estimation in the context of the performance assessment of a near surface radioactive waste repository. The algorithm, developed within the context of structural reliability, makes use of an estimated optimal importance density and a surrogate, kriging-based metamodel approximating the system response. On the basis of an accurate analytic analysis of the algorithm, a modification is proposed which allows further reducing the computational efforts by a more effective training of the metamodel. - Highlights: • We tackle uncertainty propagation in a radwaste repository performance assessment. • We improve a kriging-based importance sampling for estimating failure probabilities. • We justify the modification by an analytic, comparative analysis of the algorithms. • The probability of exceeding dose thresholds in radwaste repositories is estimated. • The algorithm is further improved reducing the number of its free parameters

  10. Project Alternative Systems Study - PASS. Analysis of performance and long-term safety of repository concepts

    International Nuclear Information System (INIS)

    Birgersson, L.; Skagius, K.; Wiborgh, M.; Widen, H.

    1992-09-01

    This study is part of the Project on Alternative Systems Study, PASS, with the overall aim to perform a technical/economical ranking of alternative repository concepts and canisters for the final storage of spent nuclear fuel. The comparison should in the first stage separately assess technology in construction and operation, long-term performance and safety, and costs. Three of the repository concepts are assumed to be located at a depth of approximately 500 m in the host rock, KBS-3, Very Long Holes (VLH) and Medium Long Holes (MLH). In the KBS-3 concept the canisters are deposited in vertical deposition holes in a system of parallel storage tunnels. In the VLH concept larger canisters are deposited in long horizontal tunnels. The MLH concept, is an evolution of the two other concepts, with KBS-3 type canisters deposited in horizontal tunnels. Smaller canisters are to be deposited in deep bore holes at a depth between 2000 to 4000 m in the Very Deep Holes (VDH) concept. In all concepts the canisters will be surrounded by a bentonite buffer. The aim of the present study is to analyze and compare the performance and long-term safety of the repository concepts. Only a qualitative comparison of the concepts is made as no calculations of radionuclide releases or dose to man have been performed. The ranking of the repository concepts was carried out by comparing the VDH, VLH and MLH concept with the KBS-3 concept. The performance and long-term safety of the repositories located at 500 m level will be based on a multiple barrier system and the predictions for the concepts will involve similar uncertainties. (54 refs.)

  11. Hydrological performance assessment on siting the high level radioactive waste repository

    International Nuclear Information System (INIS)

    Guo Yonghai; Liu Shufen; Wang Ju; Wang Zhiming; Su Rui; Lv Chuanhe; Zong Zihua

    2007-01-01

    Based on the research experiences in China and some developed countries in the world, the processes and methods on hydrological performance assessment for the siting of high radioactive repository are discussed in this paper. The methods and contents of hydrological performance assessment are discussed respectively for region, area and site hydrological investigation stages. At the same time, the hydrological performance assessment of the potential site for high level radioactive waste in China is introduced. (authors)

  12. Performance analysis for waste repositories in the nordic countries. Report for project AFA-1.2

    Energy Technology Data Exchange (ETDEWEB)

    Vuori, S. [VTT Energy (Finland); Broden, K. [Studsvik RadWaste AB (Sweden); Carugati, S.; Brodersen, K. [Forskningscenter Risoe (Denmark); Walderhaug, T. [Icelandic Radiation Protection Institute (Iceland); Helgason, J. [Ekra Geological Consulting (Iceland); Sneve, M.; Hornkjoel, S. [Norwegian Radiation Protection (Norway); Backe, S. [IFE (Norway)

    1997-02-01

    The Nordic Nuclear Safety Research (NKS) project (AFA-1) focused on safety in the final disposal of long-lived low and medium level radioactive waste and its sub project (AFA-1.2), where this report has been produced, is dealing with the performance analysis of the engineered barrier system (near-field) of the repositories for low-and medium level wastes. The topic intentionally excludes the discussion of the characteristics of the geological host medium. Therefore a more generic discussion of the features of performance analysis is possible independent of the fact that different host media are considered in the Nordic countries. The different waste management systems existing and planned in the Nordic countries are shortly described in the report. In the report main emphasis is paid on the general repositories. Some of the phenomena and interactions relevant for a generic type of repository are discussed as well. Among the different approaches for the development of scenarios for safety and performance analyses one particular method - the Rock Engineering System (RES) - was chosen to be demonstratively tested in a brainstorming session, where the possible interactions and their safety significance were discussed employing a simplified and generic Nordic repository system as the reference system. As an overall impression, the AFA-project group concludes that the use of the RES approach is very easy to learn even during a short discussion session. The use of different ways to indicate the safety significance of various interactions in a graphical user interface increases the clarity. Within the project a simple software application was developed employing a generally available spread sheet programme. The developed tool allows an easy opportunity to link the cell specific comments readily available for the `reader` of the obtained results. A short review of the performance analyses carried out in the Nordic countries for actual projects concerning repositories for

  13. Performance analysis for waste repositories in the nordic countries. Report for project AFA-1.2

    International Nuclear Information System (INIS)

    Vuori, S.; Broden, K.; Carugati, S.; Brodersen, K.; Walderhaug, T.; Helgason, J.; Sneve, M.; Hornkjoel, S.; Backe, S.

    1997-02-01

    The Nordic Nuclear Safety Research (NKS) project (AFA-1) focused on safety in the final disposal of long-lived low and medium level radioactive waste and its sub project (AFA-1.2), where this report has been produced, is dealing with the performance analysis of the engineered barrier system (near-field) of the repositories for low-and medium level wastes. The topic intentionally excludes the discussion of the characteristics of the geological host medium. Therefore a more generic discussion of the features of performance analysis is possible independent of the fact that different host media are considered in the Nordic countries. The different waste management systems existing and planned in the Nordic countries are shortly described in the report. In the report main emphasis is paid on the general repositories. Some of the phenomena and interactions relevant for a generic type of repository are discussed as well. Among the different approaches for the development of scenarios for safety and performance analyses one particular method - the Rock Engineering System (RES) - was chosen to be demonstratively tested in a brainstorming session, where the possible interactions and their safety significance were discussed employing a simplified and generic Nordic repository system as the reference system. As an overall impression, the AFA-project group concludes that the use of the RES approach is very easy to learn even during a short discussion session. The use of different ways to indicate the safety significance of various interactions in a graphical user interface increases the clarity. Within the project a simple software application was developed employing a generally available spread sheet programme. The developed tool allows an easy opportunity to link the cell specific comments readily available for the 'reader' of the obtained results. A short review of the performance analyses carried out in the Nordic countries for actual projects concerning repositories for

  14. Radionuclide transport modelling. Performance assessment of repositories in clays

    International Nuclear Information System (INIS)

    Ruebel, A.; Becker, D.A.; Fein, E.

    2007-12-01

    This study aims at the structural characterisation of embedded flame retardants and polymers. Analysis includes determination of the phase contents as well as description of their mutual interactions as a function of their thermal history in different atmospheres (air and nitrogen). Solid-state NMR spectroscopy is the most important tool applied in this thesis. This technique enables structural information about the amorphous state of the decomposed products, determination of the thermal and thermo-oxidative conversion in different amorphous and crystalline structures, and predictions about the short-range order of the observed nuclei. In this context measurements of single pulse (SP), rotor-synchronised spin echo (RSE) and cross polarisation (CP) experiments, as well as REDOR (Rotational echo double resonance) and TRAPDOR-(Transfer of population in double resonance) have been conducted. Additionally, 11 B SP and 31 P RSE experiments have been used to study quantitatively the borate and both phosphorus and phosphate contents in the solid residues. Particular emphasis was put on quantifying crystalline and non-crystalline phosphate phases. The first system consists of a combination of the flame retardants red phosphorus (P red ) and Mg(OH) 2 in HIPS. From the results of extensive NMR experiments it was deduced that most of inserted red phosphorus remains in amorphous phosphates phases (ortho, pyro, and chain/ring phosphates) besides some crystalline phosphate phases. Decomposition characteristics such as temperature and the availability of oxygen (N 2 atmosphere/air) show a significant influence on the decomposition process and the formation of phosphate phases (crystalline/amorphous). By comparing the results of the annealing processes to the results of the cone calorimeter measurements an anaerobic decomposition way was confirmed. In a second system, thermal reactions between the two flame retardants BDP and zinc borate as well their influence on the thermal

  15. Hydrologic Monitoring in the Deep Subsurface to Support Repository Performance

    Science.gov (United States)

    Hubbell, J. M.; Heath, G. L.; Scott, C. L.

    2007-12-01

    The INL has installed and operated several vadose and ground water monitoring systems in arid and humid sites to depths of about 200m. Some of these systems have been in continuous operation for over 12 years. It is important that the systems be physically robust, simple, yet versatile enough that it can operate for extended time periods with little or no maintenance. Monitoring instruments are frequently installed and run to characterize the site, collect data during site operation, and continue to run for long-term stewardship, necessitating sensors that can be maintained or serviced. Sensors are carefully chosen based on the perceived data requirements over the life of the site. An emphasis is given on direct measurements such as tensiometers (portable and advanced), neutron probe, drain gauge, temperature, wells or sampling for fluids and gases. Other complementary data can include using TDR/capacitance, radiation detectors, and larger scale geophysical techniques (3-d resistivity and EM) for volumetric measurements. Commercially available instruments may have to be modified for their use at greater depths, to allow multiple instruments in a single borehole or to perform the intended monitoring function. Access tubes (some open at the bottom) can be placed to allow insertion of multiple sensors (radiation, neutron and portable sensors/samplers), future drilling/sampling and to install new instruments at a later time. The installation techniques and backfill materials must be chosen and the measurement technique tested to ensure representative data collection for the parameters of interest. The data collection system can be linked to climatic data (precipitation, barometric pressure, snow depth, runoff, surface water sources) that may influence the site's subsurface hydrology. The instruments are then connected to a real-time automated data collection system that collect, stores, and provides access to the data. These systems have been developed that allow easy

  16. Thermal Performance Analysis of a Geologic Borehole Repository

    Energy Technology Data Exchange (ETDEWEB)

    Reagin, Lauren [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-16

    The Brazilian Nuclear Research Institute (IPEN) proposed a design for the disposal of Disused Sealed Radioactive Sources (DSRS) based on the IAEA Borehole Disposal of Sealed Radioactive Sources (BOSS) design that would allow the entirety of Brazil’s inventory of DSRS to be disposed in a single borehole. The proposed IPEN design allows for 170 waste packages (WPs) containing DSRS (such as Co-60 and Cs-137) to be stacked on top of each other inside the borehole. The primary objective of this work was to evaluate the thermal performance of a conservative approach to the IPEN proposal with the equivalent of two WPs and two different inside configurations using Co-60 as the radioactive heat source. The current WP configuration (heterogeneous) for the IPEN proposal has 60% of the WP volume being occupied by a nuclear radioactive heat source and the remaining 40% as vacant space. The second configuration (homogeneous) considered for this project was a homogeneous case where 100% of the WP volume was occupied by a nuclear radioactive heat source. The computational models for the thermal analyses of the WP configurations with the Co-60 heat source considered three different cooling mechanisms (conduction, radiation, and convection) and the effect of mesh size on the results from the thermal analysis. The results of the analyses yielded maximum temperatures inside the WPs for both of the WP configurations and various mesh sizes. The heterogeneous WP considered the cooling mechanisms of conduction, convection, and radiation. The temperature results from the heterogeneous WP analysis suggest that the model is cooled predominantly by conduction with effect of radiation and natural convection on cooling being negligible. From the thermal analysis comparing the two WP configurations, the results suggest that either WP configuration could be used for the design. The mesh sensitivity results verify the meshes used, and results obtained from the thermal analyses were close to

  17. Third report, development of site suitability and design performance data base for a high level nuclear waste repository

    International Nuclear Information System (INIS)

    1978-05-01

    This report presents the results of mining and geotechnical studies provided as support for the development of a technical data base suitable for the generation of a regulatory framework governing high-level nuclear waste disposal: flow path models for basalts, salt domes, and crystalline rocks; simplistic model evaluations; loss of administrative control; repository conceptual designs; repository design considerations; and design performance criteria

  18. Role of groundwater oxidation potential and radiolysis on waste glass performance in crystalline repository environments

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.

    1986-01-01

    Laboratory experiments have shown that groundwater conditions in a granite repository will be as reducing as those in a basalt repository. Chemical analysis of the reduced groundwaters confirmed that the Fe 2+ /Fe 3+ couple controls the oxidation potential (Eh). The reducing groundwater conditions were found to decrease the time-dependent release of soluble elements (Li and B) from the waste glass. However, due to the lower solubility of multivalent elements released from the glass when the groundwaters are reducing, these elements have significantly lower concentrations in the leachates. Gamma radiolysis reduced the oxidation potential of both granitic and basaltic groundwater in the absence of both waste glass and oxygen. This occurred in tests at atmospheric pressure where H 2 could have escaped from the solution. The mechanism for this decrease in Eh is under investigation but appears related to the reactive amorphous precipitate in both groundwaters. The results of these tests suggest that radiolysis may not cause the groundwaters to become oxidizing in a crystalline repository when abundant Fe 2+ species are present

  19. R and D on performance assessment of a potential LILW repository

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Soo; Lee, Sung Hee; Han, Kyung Won; Lee, Y M

    2001-01-01

    In this technical report Important issues and assessment methods related to post-closure safety of a proposed repository has been discussed, regarding LILW disposal. At first, to summarize the new proposal on the amendment of the MOST Notice 96-16, KAERI set up the overall directions on future R and D over performance assessment. In addition relevant overseas project such as Finnish POSIVA's VLJ repository project was thoroughly reviewed along with the recent progress of the gas generation and migration R and D. In the post-closure safety analysis of the VLJ repository, in addition to the normal evolution scenario, several disturbed evolution and accident scenarios have been analysed. The groundwater flow analysis and the biosphere analysis have been evaluated. The result of the safety analysis show that radiation doses of any significance are caused only if a well is bored in the vicinity of the repository or if the groundwater discharge spot is inhabited and used for cultivation. in the reference scenario the maximum expectation value of the individual dose rate is 0.03 mSv/a. in the realistic scenario the maximum expectation value of the dose rate is 0.0002 mSv/a In general gas generation sources are represented by radioactive gases and non-radioactive gases. The amount of radioactive gases is little that it does not make a significant influence on the safety of LILW repository, however non-radioactive gases can cause safety problem. As mentioned above, gas of LILW generated by corrosion and microbiology and their production rate can be estimated by computer simulation and long-term experiment.

  20. R and D on performance assessment of a potential LILW repository

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Soo; Lee, Sung Hee; Han, Kyung Won; Lee, Y. M

    2001-01-01

    In this technical report Important issues and assessment methods related to post-closure safety of a proposed repository has been discussed, regarding LILW disposal. At first, to summarize the new proposal on the amendment of the MOST Notice 96-16, KAERI set up the overall directions on future R and D over performance assessment. In addition relevant overseas project such as Finnish POSIVA's VLJ repository project was thoroughly reviewed along with the recent progress of the gas generation and migration R and D. In the post-closure safety analysis of the VLJ repository, in addition to the normal evolution scenario, several disturbed evolution and accident scenarios have been analysed. The groundwater flow analysis and the biosphere analysis have been evaluated. The result of the safety analysis show that radiation doses of any significance are caused only if a well is bored in the vicinity of the repository or if the groundwater discharge spot is inhabited and used for cultivation. in the reference scenario the maximum expectation value of the individual dose rate is 0.03 mSv/a. in the realistic scenario the maximum expectation value of the dose rate is 0.0002 mSv/a In general gas generation sources are represented by radioactive gases and non-radioactive gases. The amount of radioactive gases is little that it does not make a significant influence on the safety of LILW repository, however non-radioactive gases can cause safety problem. As mentioned above, gas of LILW generated by corrosion and microbiology and their production rate can be estimated by computer simulation and long-term experiment.

  1. Elicitation and use of expert judgment in performance assessment for high-level radioactive waste repositories

    International Nuclear Information System (INIS)

    Bonano, E.J.; Hora, S.C.; Keeney, R.L.; von Winterfeldt, D.

    1990-05-01

    This report presents the concept of formalizing the elicitation and use of expert judgment in the performance assessment of high-level radioactive waste (HLW) repositories in deep geologic formations. The report begins with a discussion of characteristics (advantages and disadvantages) of formalizing expert judgment examples of previous uses of expert judgment in radioactive waste programs, criteria that can assist in deciding when to formalize expert judgment, and the relationship of formal use of expert judgment to data collection and modeling. The current state of the art with respect to the elicitation, use, and communication of formal expert judgment is presented. The report concludes with a discussion on potential applications of formal expert judgment in performance assessment of HLW repositories. 93 refs

  2. A suggested approach toward measuring sorption and applying sorption data to repository performance assessment

    International Nuclear Information System (INIS)

    Rundberg, R.S.

    1992-01-01

    The prediction of radionuclide migration for the purpose of assessing the safety of a nuclear waste repository will be based on a collective knowledge of hydrologic and geochemical properties of the surrounding rock and groundwater. This knowledge along with assumption about the interactions of radionuclides with groundwater and minerals form the scientific basis for a model capable of accurately predicting the repository's performance. Because the interaction of radionuclides in geochemical systems is known to be complicated, several fundamental and empirical approaches to measuring the interaction between radionuclides and the geologic barrier have been developed. The approaches applied to the measurement of sorption involve the use of pure minerals, intact, or crushed rock in dynamic and static experiments. Each approach has its advantages and disadvantages. There is no single best method for providing sorption data for performance assessment models which can be applied without invoking information derived from multiple experiments. 53 refs., 12 figs

  3. Identifying significant uncertainties in thermally dependent processes for repository performance analysis

    International Nuclear Information System (INIS)

    Gansemer, J.D.; Lamont, A.

    1994-01-01

    In order to study the performance of the potential Yucca Mountain Nuclear Waste Repository, scientific investigations are being conducted to reduce the uncertainty about process models and system parameters. This paper is intended to demonstrate a method for determining a strategy for the cost effective management of these investigations. It is not meant to be a complete study of all processes and interactions, but does outline a method which can be applied to more in-depth investigations

  4. Parametric study of geohydrologic performance characteristics for nuclear-waste repositories

    International Nuclear Information System (INIS)

    Bailey, C.E.; Marine, I.W.

    1981-01-01

    Purpose of this study was to present geohydrologic information in graphical form covering a wide range of parameters to aid in determining site specifications based on functional criteria. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater were developed. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere

  5. A THM stress-strain framework for modelling the performance of argillaceous materials in deep repositories for radioactive waste

    International Nuclear Information System (INIS)

    Laloui, L.; Francois, B.

    2007-01-01

    In the scenarios for deep, geological nuclear-waste repositories, clayey soils will be hydrated, heated, cooled and dried. The numerical modelling of these mechanical processes is a key issue. Performance assessment of deep repositories for heat-generating radioactive waste would benefit from improvements in mechanical stress-strain constitutive modelling of the coupled thermo-hydro-mechanical behaviour. The presented framework allows progress in understanding the most involved phenomena relevant to nuclear-waste repositories and their coupled nature. It could be used both in the design and in the performance assessment of repositories. It may be applied to disposal in clay formations and to hard-rock repositories where artificially compacted clay is to be used as buffer and backfill. Such a constitutive framework may help in understanding some unexplained or controversial behaviours and in defining experimental programmes to answer key questions. (author)

  6. Interim performance specifications for conceptual waste-package designs for geologic isolation in salt repositories

    International Nuclear Information System (INIS)

    1983-06-01

    The interim performance specifications and data requirements presented apply to conceptual waste package designs for all waste forms which will be isolated in salt geologic repositories. The waste package performance specifications and data requirements respond to the waste package performance criteria. Subject areas treated include: containment and controlled release, operational period safety, criticality control, identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

  7. Key radionuclides and parameters that determine performance of geologic repositories for high-level radioactive wastes

    International Nuclear Information System (INIS)

    Joonhong Ahn; Atsuyuki Suzuki

    1993-01-01

    This paper presents results of a mathematical analysis for performance of the engineered barriers of high-level radioactive waste repositories. The main body of the mathematical model developed in this study is mass transport of actinides in a bentonite region. In an analysis of actinide transport, radioactive decay chain and effects of low solubilities must be taken into account. In many previous models for mass transport in engineered barriers including radioactive decay chain, however, boundary conditions at the interface between the waste form and the bentonite region cannot be determined flexibly. In some models, solubility-limited boundary condition is assumed for all the members in a chain. In order to investigate what are key radionuclides and parameters that control performance of engineered barriers of a geologic repository, we must evaluate mass transport with the source boundary condition determined by a detailed analysis on mass transfer at the boundary. In this study, we developed a mathematical model, which can determine whether the inner boundary condition is solubility-limited or congruent release, based on a mathematical analysis for mass transfer at the glass dissolution location, and how long the solubility-limited boundary condition applies. Based on the mathematical model, we point out radionuclides and parameters that have primary influences on the performance of a repository, and investigate a reasonable strategy for coupling geologic disposal and partitioning of those key radionuclides from the standpoint of reducing hazard of geologic disposal. (authors). 4 tabs., 2 figs., 8 refs

  8. Properties of altered soils by alkaline solution: contribution in the performance evaluation of repositories

    International Nuclear Information System (INIS)

    Calabria, Jaqueline Alves de Almeida

    2015-01-01

    The radioactive wastes from nuclear technology applications must be properly disposed in a repository, during the necessary time to ensure the human and the environment protection. The surface systems are largely considered for disposal of low and intermediate level radioactive waste, but generally require the use of engineering barriers to control the radionuclides release. An important engineering barrier is the backfill which is situated between the package and structural material, and has the functions of reducing the water infiltration and to promote the retardation of the radionuclide migration, among others. Therefore, the material to be used as backfill such as clays, cement, soils, rocks, must has good sorption, permeability and mechanical properties. The selection of the material will depend also largely on the material availability and installation design. The concrete is also used in the construction of repository, and its interaction with water induces its degradation, resulting in a high pH solution. This solution interacts with the backfilling materials promoting mineralogical alterations that results in significant changes in their key properties and performance as safety component of the repository. In this work, five Brazilian soils of Minas Gerais state, selected according to their generic characteristics along with information from Sistema Brasileiro de Classificacao de Solos (SiBCS) were investigated concerning their potential use as backfilling material in a superficial repository by the determination of retention capacity for cesium and iodine. Sorption-related parameters, used in the performance assessment of the soils, were obtained from experimental data fitting to different sorption isotherms models. The soil that showed the best sorption of Cs, was a clay soil that presented distribution coefficient (K_d) of 90.5 mL.g"-"1 and maximum sorption capacity (Q_m_a_x) of 18.372 mg.g"-"1. Regarding the iodine, the sorption was very low for all

  9. Safety performance of a near surface repository subject to a fuel burning

    International Nuclear Information System (INIS)

    Stefanini, Lorenzo; Frano, Rosa Lo; Forasassi, Giuseppe

    2015-01-01

    This study aims to investigate the performances of a near surface repository subject to fuel burning occurring simultaneously or subsequently to a large commercial aircraft impact. Specifically the thermal effects caused by a Boeing-747 crushing (considered like “beyond design basis accident”) are studied. An important part of this study is the analysis of the possible (thermo-mechanical) degradation effects, as dehydration, degasification, pressurization, etc. that the concrete may undergo, particularly in the case of prolonged fire, and of the resistance of structure itself in this condition. Conservative assumptions and restrictions have been made with regard to the fire scenario, the maximum temperature of which is calculated on the basis of the fuel airplane amount, the normal impact, the variation of the material properties along with the temperature as well the damaging phenomena of concrete. The airplane impact load, calculated with the Riera approach, and the maximum temperature, reached during the fuel combustion, are used as input (boundary condition) in the numerical simulations performed by MARC© code. The obtained results showed that a repository wall thickness, ranging from 0.6 to 0.9 m, is not sufficient to prevent the local penetration of wall. To reduce the computational cost, the analyses have been made only on a half part of the structure, highlighting the dominance of thermal effects. Despite the ongoing concrete degradation phenomena, the overall integrity of the repository seemed to be guaranteed as well as the containment and the confinement of radioactive waste. (author)

  10. Role of natural analogs in performance assessment of nuclear waste repositories

    International Nuclear Information System (INIS)

    Sagar, B.; Wittmeyer, G.W.

    1995-01-01

    Mathematical models of the flow of water and transport of radionuclides in porous media will be used to assess the ability of deep geologic repositories to safely contain nuclear waste. These models must, in some sense, be validated to ensure that they adequately describe the physical processes occurring within the repository and its geologic setting. Inasmuch as the spatial and temporal scales over which these models must be applied in performance assessment are very large, validation of these models against laboratory and small-scale field experiments may be considered inadequate. Natural analogs may provide validation data that are representative of physico-chemical processes that occur over spatial and temporal scales as large or larger than those relevant to repository design. The authors discuss the manner in which natural analog data may be used to increase confidence in performance assessment models and conclude that, while these data may be suitable for testing the basic laws governing flow and transport, there is insufficient control of boundary and initial conditions and forcing functions to permit quantitative validation of complex, spatially distributed flow and transport models. The authors also express their opinion that, for collecting adequate data from natural analogs, resources will have to be devoted to them that are much larger than are devoted to them at present

  11. Sellafield repository design concept

    International Nuclear Information System (INIS)

    1998-01-01

    Between 1989 and 1997, UK Nirex Ltd carried out a programme of investigations to evaluate the potential of a site adjacent to the BNFL Sellafield works to host a deep repository for the United Kingdom's intermediate-level and certain low-level radioactive waste. The programme of investigations was wound down following the decision in March 1997 to uphold the rejection of the Company's planning application for the Rock Characterisation Facility (RCF), an underground laboratory which would have allowed further investigations to confirm whether or not the site would be suitable. Since that time, the Company's efforts in relation to the Sellafield site have been directed towards documenting and publishing the work carried out. The design concept for a repository at Sellafield was developed in parallel with the site investigations through an iterative process as knowledge of the site and understanding of the repository system performance increased. This report documents the Sellafield repository design concept as it had been developed, from initial design considerations in 1991 up to the point when the RCF planning application was rejected. It shows, from the context of a project at that particular site, how much information and experience has been gained that will be applicable to the development of a deep waste repository at other potential sites

  12. Use of Groundwater Lifetime Expectancy for the Performance Assessment of Deep Geologic Radioactive Waste Repositories.

    Science.gov (United States)

    Cornaton, F.; Park, Y.; Normani, S.; Sudicky, E.; Sykes, J.

    2005-12-01

    Long-term solutions for the disposal of toxic wastes usually involve isolation of the wastes in a deep subsurface geologic environment. In the case of spent nuclear fuel, the safety of the host repository depends on two main barriers: the engineered barrier and the natural geological barrier. If radionuclide leakage occurs from the engineered barrier, the geological medium represents the ultimate barrier that is relied upon to ensure safety. Consequently, an evaluation of radionuclide travel times from the repository to the biosphere is critically important in a performance assessment analysis. In this study, we develop a travel time framework based on the concept of groundwater lifetime expectancy as a safety indicator. Lifetime expectancy characterizes the time radionuclides will spend in the subsurface after their release from the repository and prior to discharging into the biosphere. The probability density function of lifetime expectancy is computed throughout the host rock by solving the backward-in-time solute transport equation subject to a properly posed set of boundary conditions. It can then be used to define optimal repository locations. In a second step, the risk associated with selected sites can be evaluated by simulating an appropriate contaminant release history. The proposed methodology is applied in the context of a typical Canadian Shield environment. Based on a statistically-generated three-dimension network of fracture zones embedded in the granitic host rock, the sensitivity and the uncertainty of lifetime expectancy to the hydraulic and dispersive properties of the fracture network, including the impact of conditioning via their surface expressions, is computed in order to demonstrate the utility of the methodology.

  13. Review on technical issues influencing the performance of chemical barriers of TRU waste repository

    International Nuclear Information System (INIS)

    Fujita, Tomonari; Sugiyama, Daisuke; Tsukamoto, Masaki; Yokoyama, Hayaichi

    1997-01-01

    Studies of technical issues influencing the performance assessment of TRU waste disposal which is occurred from the nuclear fuel reprocessing were reviewed in related to the development of safety analysis method. Especially, the chemical containment was investigated as a key barrier to radionuclide migration. TRU waste including long-lived radionuclides need long-term performance assessment which could be assumed only by the chemical barrier. The description of technical issues concerned with the performance of TRU waste repository has been divided into the following categories: long-term degradation of cementitious materials as engineered barrier for radionuclide migration, effect of colloids, organic macromolecules and organic degradation products on chemical behavior of radionuclides, gas generation by corrosion of metallic wastes, and effects of microbial activity. Preliminary performance assessment indicated that important factors affecting performance of chemical barriers in near-field were the distribution coefficient and the solubility of radionuclides in near-field groundwater. Therefore, it was identified that key issues associated with performance of chemical barrier were evaluation of (a) the long-term change of distribution coefficient of cementitious material through the degradation under repository condition and (b) chemical speciation change of radionuclides such as increase of solubility by the presence of colloidal-size materials. (author)

  14. Total system performance predictions (TSPA-1995) for the potential high-level waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Sevougian, S.D.; Andrews, R.W.; McNeish, J.A.

    1996-01-01

    The management and operating contractor for the potential high-level nuclear waste repository at Yucca Mountain, Nevada, has been recently completed a new performance assessment of the ability of the repository to isolate and contain nuclear waste for long time periods (up to 1,000,000 years). Sensitivity analyses determine the most important physical parameters and processes, using the most current information and models

  15. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    International Nuclear Information System (INIS)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-01

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  16. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    Energy Technology Data Exchange (ETDEWEB)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-15

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  17. Safety- and performance indicators for a generic deep geological repository in clay

    International Nuclear Information System (INIS)

    Resele, G.; Niemeyer, M.; Wilhelm, St.; Heimer, St.; Mohlfeld, M.; Eilers, G.; Preuss, J.; Wollrath, J.

    2010-01-01

    Document available in extended abstract form only. As a first step of an impartial survey for an optimal site selection for a deep geological repository in Germany, potentially suitable regions shall be identified and localised according to their suitability. During the early phases of such a site selection procedure the information about the properties of the host rock and the geological situation at the potential sites is not very precise. As site investigation procedures are both expensive and time-consuming, it is essential to identify those properties of the geological barrier system that are most relevant for long-term safety. Furthermore, adequate indicators have to be chosen that allow a simple but efficient assessment of the suitability of the potential regions. Definition and application of 'exclusion criteria' based on single parameter values, e.g. the hydraulic conductivity of the host rock, is inadequate because the long-term safety depends on the interaction of many features and properties of the barrier system. In a research project, indicators have been developed which depend on the most relevant properties of the geological barriers and estimate the overall performance of a repository system. The application of these indicators on the barrier properties which have been found during the investigations of potential repository sites in clay located in Germany, Switzerland and France demonstrates how, for instance, an unfavourably high hydraulic permeability of the clay can be compensated by a large vertical extension of the clay layer and small hydraulic gradients. Other indicators evaluate the importance of hydraulic discontinuities and define the minimal requirements on technical barriers like seals and backfill of emplacement tunnels. When the information of the radionuclide inventory and the biosphere, especially the diluting aquifer is included, the indicators allow the estimation of the resulting dose which matches the result of a

  18. The use of performance assessments in Yucca Mountain repository waste package design activities

    International Nuclear Information System (INIS)

    Jardine, L.J.

    1990-01-01

    The Yucca Mountain Project is developing performance assessment approaches as part of the evaluations of the suitability of Yucca Mountain as a repository site. Lawrence Livermore National Laboratory is developing design concepts and the scientific performance assessment methodologies and techniques used for the waste package and engineered barrier system components. This paper presents an overview of the approach under development for postclosure performance assessments that will guide the conceptual design activities and assist in the site suitability evaluations. This approach includes establishing and modeling for the long time periods required by regulations: near-field environment characteristics surrounding the emplaced wastes; container materials performance responses; and waste form properties. All technical work is being done under a fully qualified quality assurance program

  19. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    International Nuclear Information System (INIS)

    Min, Ki-Bok; Stephansson, Ove

    2009-03-01

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  20. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    Energy Technology Data Exchange (ETDEWEB)

    Min, Ki-Bok (School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, Adelaide (Australia)); Stephansson, Ove (Steph Rock Consulting AB, Berlin (Germany))

    2009-03-15

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  1. Performance assessments of nuclear waste repositories--A dialogue on their value and limitations

    Science.gov (United States)

    Ewing, Rodney C.; Tierney, Martin S.; Konikow, Leonard F.; Rechard, Rob P.

    1999-01-01

    Performance Assessment (PA) is the use of mathematical models to simulate the long-term behavior of engineered and geologic barriers in a nuclear waste repository; methods of uncertainty analysis are used to assess effects of parametric and conceptual uncertainties associated with the model system upon the uncertainty in outcomes of the simulation. PA is required by the U.S. Environmental Protection Agency as part of its certification process for geologic repositories for nuclear waste. This paper is a dialogue to explore the value and limitations of PA. Two “skeptics” acknowledge the utility of PA in organizing the scientific investigations that are necessary for confident siting and licensing of a repository; however, they maintain that the PA process, at least as it is currently implemented, is an essentially unscientific process with shortcomings that may provide results of limited use in evaluating actual effects on public health and safety. Conceptual uncertainties in a PA analysis can be so great that results can be confidently applied only over short time ranges, the antithesis of the purpose behind long-term, geologic disposal. Two “proponents” of PA agree that performance assessment is unscientific, but only in the sense that PA is an engineering analysis that uses existing scientific knowledge to support public policy decisions, rather than an investigation intended to increase fundamental knowledge of nature; PA has different goals and constraints than a typical scientific study. The “proponents” describe an ideal, sixstep process for conducting generalized PA, here called probabilistic systems analysis (PSA); they note that virtually all scientific content of a PA is introduced during the model-building steps of a PSA, they contend that a PA based on simple but scientifically acceptable mathematical models can provide useful and objective input to regulatory decision makers. The value of the results of any PA must lie between these two

  2. Spent fuel performance assessment (SPA) for a hypothetical repository in crystalline formations in Germany

    International Nuclear Information System (INIS)

    Luehrmann, L.; Noseck, U.; Storck, R.

    2000-07-01

    Within the framework of this project a first long-term safety assessment study for a generic German repository with spent nuclear fuel in granite host formations has been performed. Conceptual models have been developed and implemented into the numerical codes. These models describe the relevant processes in the near and far field of the repository. For the nuclide mobilisation and the diffusion-controlled transport through the bentonite barrier the computer code GRAPOS for far-field transport the code CHETMAD has been developed. Transport in the far field has been assumed to take place in a fracture network. As retardation mechanism matrix diffusion accompanied by linear equilibrium sorption on the rock matrix is considered. Both codes have been tested by intercomparison with codes of other countries. The dose rates have been calculated by the code EXCON considering the transport pathways into the biosphere. A reference scenario has been defined. It considers instantaneous saturation of the bentonite immediately after the operational phase of the repository, failure of all containers after 1000 years, diffusion through the bentonite, transport through fractured dykes, which represent a fast transport pathway in the low permeability region of the granite. The nuclide mobilization has been calculated according to a common source term which has been developed by all participants of the SPA project. It is assumed that 25% of the containers are connected to the considered transport pathway in the far field. The nuclides are transported to layers close to the surface. The contaminated water is pumped from a surface well and used for drinking, irrigation, cattle feed and fish ponds. (orig.) [de

  3. Performance Assessment of a Generic Repository in Bedded Salt for DOE-Managed Nuclear Waste

    Science.gov (United States)

    Stein, E. R.; Sevougian, S. D.; Hammond, G. E.; Frederick, J. M.; Mariner, P. E.

    2016-12-01

    A mined repository in salt is one of the concepts under consideration for disposal of DOE-managed defense-related spent nuclear fuel (SNF) and high level waste (HLW). Bedded salt is a favorable medium for disposal of nuclear waste due to its low permeability, high thermal conductivity, and ability to self-heal. Sandia's Generic Disposal System Analysis framework is used to assess the ability of a generic repository in bedded salt to isolate radionuclides from the biosphere. The performance assessment considers multiple waste types of varying thermal load and radionuclide inventory, the engineered barrier system comprising the waste packages, backfill, and emplacement drifts, and the natural barrier system formed by a bedded salt deposit and the overlying sedimentary sequence (including an aquifer). The model simulates disposal of nearly the entire inventory of DOE-managed, defense-related SNF (excluding Naval SNF) and HLW in a half-symmetry domain containing approximately 6 million grid cells. Grid refinement captures the detail of 25,200 individual waste packages in 180 disposal panels, associated access halls, and 4 shafts connecting the land surface to the repository. Equations describing coupled heat and fluid flow and reactive transport are solved numerically with PFLOTRAN, a massively parallel flow and transport code. Simulated processes include heat conduction and convection, waste package failure, waste form dissolution, radioactive decay and ingrowth, sorption, solubility limits, advection, dispersion, and diffusion. Simulations are run to 1 million years, and radionuclide concentrations are observed within an aquifer at a point approximately 4 kilometers downgradient of the repository. The software package DAKOTA is used to sample likely ranges of input parameters including waste form dissolution rates and properties of engineered and natural materials in order to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia

  4. Supplemental Performance Analyses for the Potential High-Level Nuclear Waste Repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Sevougian, S. D.; McNeish, J. A.; Coppersmith, K.; Jenni, K. E.; Rickertsen, L. D.; Swift, P. N.; Wilson, M. L.

    2002-01-01

    The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for the potential development of a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. To facilitate public review and comment, in May 2001 the DOE released the Yucca Mountain Science and Engineering Report (S and ER) (1), which presents technical information supporting the consideration of the possible site recommendation. The report summarizes the results of more than 20 years of scientific and engineering studies. Based on internal reviews of the S and ER and its key supporting references, the Total System Performance Assessment for the Site Recommendation (TSPA-SR) (2) and the Analysis Model Reports and Process Model Reports cited therein, the DOE has recently identified and performed several types of analyses to supplement the treatment of uncertainty in support of the consideration of a possible site recommendation. The results of these new analyses are summarized in the two-volume report entitled FY01 Supplemental Science and Performance Analysis (SSPA) (3,4). The information in this report is intended to supplement, not supplant, the information contained in the S and ER. The DOE recognizes that important uncertainties will always remain in any assessment of the performance of a potential repository over thousands of years (1). One part of the DOE approach to recognizing and managing these uncertainties is a commitment to continued testing and analysis and to the continued evaluation of the technical basis supporting the possible recommendation of the site, such as the analysis contained in the SSPA. The goals of the work described here are to provide insights into the implications of newly quantified uncertainties, updated science, and evaluations of lower operating temperatures on the performance of a potential Yucca Mountain repository and to increase confidence in the results of the TSPA described

  5. Repository design

    Energy Technology Data Exchange (ETDEWEB)

    John, C M

    1982-01-01

    Various technical issues of radioactive waste design are addressed in this paper. Two approaches to repository design considered herein are: (1) design to minimize the disturbance of the hot rock; and (2) designs that intentionally modify the hot rock to insure better containment of the wastes. The latter designs range from construction of a highly impermeable barrier around a spherical cavern to creating a matrix of tunnels and boreholes to form a cage within which the hydraulic pressure is nearly constant. Examples of these design alternatives are described in some detail. It is concluded that proposed designs for repositories illustrate that performance criteria considered acceptable for such facilities can be met by appropriate site selection and repository engineering. With these technically feasible design concepts, it is also felt that socioeconomic and institutional issues can be better resolved. (BLM)

  6. Repository exploration

    International Nuclear Information System (INIS)

    Pentz, D.L.

    1984-01-01

    This paper discusses exploration objectives and requirements for a nuclear repository in the U.S.A. The importance of designing the exploration program to meet the system performance objectives is emphasized and some examples of the extent of exploration required before the License Application for Construction Authorization is granted are also discussed

  7. Sources/treatment of uncertainties in the performance assessment of geologic radioactive waste repositories

    International Nuclear Information System (INIS)

    Cranwell, R.M.

    1987-01-01

    Uncertainties in the performance assessment of geologic radioactive waste repositories have several sources. The more important ones include: 1) uncertainty in the conditions of a disposal system over the temporal scales set forth in regulations, 2) uncertainty in the conceptualization of the geohydrologic system, 3) uncertainty in the theoretical description of a given conceptual model of the system, 4) uncertainty in the development of computer codes to implement the solution of a mathematical model, and 5) uncertainty in the parameters and data required in the models and codes used to assess the long-term performance of the disposal system. This paper discusses each of these uncertainties and outlines methods for addressing these uncertainties

  8. Safety and performance indicators for repositories in salt and clay formations

    International Nuclear Information System (INIS)

    Wolf, Jens; Ruebel, Andre; Noseck, Ulrich; Becker, Dirk

    2008-07-01

    The GRS (Gesellschaft fuer Reaktorsicherheit) study aims to the identification of suitable indicators for repositories in salt and clay formation. It is not intended to compare the two formations with respect to the safe disposal of radioactive waste. A first set of safety and performance indicators for both host rocks has been derived on the basis of results of the SPIN project. Reference values for the safety indicators have been determined. The suitability of the indicators and their significance for different time frames Is demonstrated by means of deterministic model calculations and external parameter variations of previous studies. The safety indicators considered in the report are the effective dose rate (Sv/a), the radiotoxicity concentration in the biosphere water (Sv/m 3 ) and the radiotoxicity flux from the geosphere (overlying rock) (Sv/a). The performance indicators considered in the study are the radiotoxicity inventory in different compartments (S), radiotoxicity fluxes from compartments and the integrated radiotoxicity fluxes from compartments (Sv).

  9. Repository Integration Program: RIP performance assessment and strategy evaluation model theory manual and user's guide

    International Nuclear Information System (INIS)

    1995-11-01

    This report describes the theory and capabilities of RIP (Repository Integration Program). RIP is a powerful and flexible computational tool for carrying out probabilistic integrated total system performance assessments for geologic repositories. The primary purpose of RIP is to provide a management tool for guiding system design and site characterization. In addition, the performance assessment model (and the process of eliciting model input) can act as a mechanism for integrating the large amount of available information into a meaningful whole (in a sense, allowing one to keep the ''big picture'' and the ultimate aims of the project clearly in focus). Such an integration is useful both for project managers and project scientists. RIP is based on a '' top down'' approach to performance assessment that concentrates on the integration of the entire system, and utilizes relatively high-level descriptive models and parameters. The key point in the application of such a ''top down'' approach is that the simplified models and associated high-level parameters must incorporate an accurate representation of their uncertainty. RIP is designed in a very flexible manner such that details can be readily added to various components of the model without modifying the computer code. Uncertainty is also handled in a very flexible manner, and both parameter and model (process) uncertainty can be explicitly considered. Uncertainty is propagated through the integrated PA model using an enhanced Monte Carlo method. RIP must rely heavily on subjective assessment (expert opinion) for much of its input. The process of eliciting the high-level input parameters required for RIP is critical to its successful application. As a result, in order for any project to successfully apply a tool such as RIP, an enormous amount of communication and cooperation must exist between the data collectors, the process modelers, and the performance. assessment modelers

  10. Development of design window evaluation and display system. 1. System development and performance confirmation

    International Nuclear Information System (INIS)

    Muramatsu, Toshiharu; Yamaguchi, Akira

    2003-07-01

    Purpose: The work was performed to develop a design window evaluation and display system for the purpose of obtaining the effects of various design parameters on the typical thermal hydraulic issues resulting from a use of various kind of working fluid etc. easily. Method: The function of the system were 'confirmation of design margin' of the present design, 'confirmation of the affected design zone' when a designer changed some design parameter, and search for an design improvement' for design optimization. The system was developed using existing soft wares on PC and the database relating analytical results of typical thermal hydraulic issues provided by separate work. Results: (1) System design: In order to develop a design window evaluation and display system, 'numerical analysis unit', 'statistical analysis unit', 'MMI unit', 'optimization unit' were designed based on the result of selected optimization procedure and display visualization. Further, total system design was performed combining these units. Typical thermal hydraulic issues to be considered are upper plenum thermal hydraulics, thermal stratification, free surface sloshing, flow-induced vibration of a heat exchanger and thermal striping in the T-junction piping systems. (2) Development of prototype system and a functional check: A prototype system of a design window evaluation and display system was developed and the functions were confirmed as was planned. (author)

  11. Development of models for use in the assessment of waste repository performance

    International Nuclear Information System (INIS)

    Dickson, A.G.; Weare, J.H.

    1989-09-01

    The work outlined in this proposal is intended both to provide thermodynamic data that is needed to assist in the assessment of waste repository performance and the modeling necessary to ascertain to what extent the data produced is consistent, both with itself and with other published data on related systems. During this stage of the research we shall endeavor to develop a model of the chemistry of aluminum in aqueous solution which is consistent with a wide variety of experimental data including data generated as part of this project together with data that has been published previously in the research literature. We propose a program of research designed to enable us to model the interaction of canister materials (e.g. copper and iron) with natural waters. Both experimental work and a modeling program are outlined. In the experimental program e.m.f. measurements and spectroscopic measurements will be made so as to determine the various association equilibria of iron and copper with the anions OH-, HCO 3 - , and CO 3 2- . The initial stages of the modeling program will concentrate on the identification and use of existing experimental data to produce a preliminary model. This will allow us to identify those areas where special emphasis should be placed to meet the needs of the waste disposal program objectives. The objective of this research is to produce thermodynamic data for use in the assessment of waste repository performance that has been measured using experimental procedures performed in accord with the Level 1 quality assurance requirements detailed in the L.L.N.L. Yucca Mountain Project Quality Procedures Manual. The modeling approach used in experimental planning and data assessment is a Level 3 activity. In addition to the establishment of the thermodynamic data base proposed here, results should lead to improved consistency in the overall modeling effort. 29 refs., 2 tabs

  12. The impact of episodic nonequilibrium fracture-matrix flow on geological repository performance

    International Nuclear Information System (INIS)

    Buscheck, T.A.; Nitao, J.J.; Chestnut, D.A.

    1991-01-01

    Adequate representation of fracture-matrix interaction during episodic infiltration events is crucial in making valid hydrological predictions of repository performance at Yucca Mountain. Various approximations have been applied to represent fracture-matrix flow interaction, including the Equivalent Continuum Model (ECM), which assumes capillary equilibrium between fractures and matrix, and the Fracture-Matrix Model (FMM), which accounts for nonequilibrium fracture-matrix flow. We analyze the relative impact of matrix imbibition on episodic nonequilibrium fracture-matrix flow for the eight major hydrostratigraphic units in the unsaturated zone at Yucca Mountain. Comparisons are made between ECM and FMM predictions to determine the applicability of the ECM. The implications of nonequilibrium fracture-matrix flow on radionuclide transport are also discussed

  13. Uncertainties in repository performance from spatial variability of hydraulic conductivities - statistical estimation and stochastic simulation using PROPER

    International Nuclear Information System (INIS)

    Lovius, L.; Norman, S.; Kjellbert, N.

    1990-02-01

    An assessment has been made of the impact of spatial variability on the performance of a KBS-3 type repository. The uncertainties in geohydrologically related performance measures have been investigated using conductivity data from one of the Swedish study sites. The analysis was carried out with the PROPER code and the FSCF10 submodel. (authors)

  14. Uncertainty and sensitivity analysis in performance assessment for the proposed high-level radioactive waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Helton, Jon C.; Hansen, Clifford W.; Sallaberry, Cédric J.

    2012-01-01

    Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. As part of this development, a detailed performance assessment (PA) for the YM repository was completed in 2008 and supported a license application by the DOE to the U.S. Nuclear Regulatory Commission (NRC) for the construction of the YM repository. The following aspects of the 2008 YM PA are described in this presentation: (i) conceptual structure and computational organization, (ii) uncertainty and sensitivity analysis techniques in use, (iii) uncertainty and sensitivity analysis for physical processes, and (iv) uncertainty and sensitivity analysis for expected dose to the reasonably maximally exposed individual (RMEI) specified the NRC’s regulations for the YM repository. - Highlights: ► An overview of performance assessment for the proposed Yucca Mountain radioactive waste repository is presented. ► Conceptual structure and computational organization are described. ► Uncertainty and sensitivity analysis techniques are described. ► Uncertainty and sensitivity analysis results for physical processes are presented. ► Uncertainty and sensitivity analysis results for expected dose are presented.

  15. Pathological confirmation of nerve-sparing types performed during robot-assisted radical prostatectomy (RARP).

    Science.gov (United States)

    Ko, Woo Jin; Hruby, Gregory W; Turk, Andrew T; Landman, Jaime; Badani, Ketan K

    2013-03-01

    WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Incremental nerve-sparing techniques (NSTs) improve postoperative erectile function after robot-assisted radical prostatectomy (RARP). However, there are no studies to date that histologically confirm the surgeon intended NST. Thus, in the present study, we histologically confirmed that the surgeon performed the nerve preservation as his intended NSTs during RARP. Also, we found that there was more variability in fascia width outcome on the left side compared with the right. Therefore, when performing nerve preservation on the surgeon's non-dominant side, we need to pay more close attention. To confirm that the surgeon achieved true intended histological nerve sparing during robot-assisted radical prostatectomy (RARP) by studying RP specimens. To aid the novice robotic surgeon to develop the skills of RARP. Between June 2008 and May 2009, 122 consecutive patients underwent RARP by a single surgeon (K.K.B.). The degree of nerve sparing (wide resection [WR], interfascial nerve sparing [ITE-NS], intrafascial nerve sparing [ITR-NS]) on both sides was recorded. The posterior sectors of RP specimens from distal, mid, and proximal parts were evaluated. Fascia width (FW) of each position in RP specimens were compared across nerve-sparing types (NSTs). FW was recorded at 15 ° intervals (3-9 o'clock position), measured as the distance between the outermost prostate gland and surgical margin. The slides were reviewed by an experienced uropathologist who was 'blinded' to the NST. In all, 93 men were included. The overall mean (sd) FW was the greatest in the order of WR, ITE-NS, and ITR-NS, at 2.42 (1.62), 1.71 (1.40) and 1.16 (1.08) mm, respectively (P ITE-NS, bilateral ITE-NS, ITE-NS/WR, and bilateral WR, respectively. To further validate and confirm these preliminary findings, additional studies involving multicentre cohorts would be required. The surgeon intended dissection and FW correlate, with ITR

  16. Performance Confirmation for the Engineered Barrier System. Report of a Workshop

    International Nuclear Information System (INIS)

    Bennett, David G.

    2004-08-01

    As part of preparations for review of future license applications, the Swedish Nuclear Power Inspectorate (SKI) organised a workshop on the engineered barrier system for the KBS-3 concept, focused on Performance Confirmation (PC). The workshop was held during 12 - 14 May, 2004 at Oskarshamn. The main purpose of the workshop was to identify key issues relating to the demonstration of long-term safety using a system of engineered barriers. The workshop began with introductory presentations on Performance Confirmation, on monitoring, and on long-term experiments in underground research laboratories. Working groups were then convened to discuss these topics and identify questions to put to the Swedish Nuclear Fuel and Waste Management Company (SKB) the following day. On the second day, SKB made several presentations, mainly on long-term experiments conducted at the Aespoe underground research laboratory. These presentations were followed by an informal session during which the questions identified by the working groups on the first day were discussed with SKB and its representatives. This report includes the questions identified by the working groups and a summary of the workshop discussions. Extended abstracts for the introductory presentations are included in an appendix. The conclusions and viewpoints presented in this report are those of one or several workshop participants. They do not necessarily coincide with those of SKI

  17. 10 CFR Appendix I to Part 960 - NRC and EPA Requirements for Postclosure Repository Performance

    Science.gov (United States)

    2010-01-01

    ... SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Pt. 960, App. I Appendix I to Part 960—NRC and... after disposal (a) releases of radioactive materials to the accessible environment that are estimated to...,000 years for a repository containing wastes generated from 100,000 metric tons of heavy metal of...

  18. Abstraction of information in repository performance assessments. Examples from the SKI project Site-94

    International Nuclear Information System (INIS)

    Dverstorp, B.; Andersson, J.

    1995-01-01

    Performance Assessment of a nuclear waste repository implies an analysis of a complex system with many interacting processes. Even if some of these processes may be known to large detail, problems arise when combining all information, and means of abstracting information from complex detailed models into models that couple different processes are needed. Clearly, one of the major objectives of performance assessment, to calculate doses or other performance indicators, implies an enormous abstraction of information compared to all information that is used as input. Other problems are that the knowledge of different parts or processes is strongly variable and adjustments, interpretations, are needed when combining models from different disciplines. In addition, people as well as computers, even today, always have a limited capacity to process information and choices have to be made. However, because abstraction of information clearly is unavoidable in performance assessment the validity of choices made, always need to be scrutinized and judgements made need to be updated in an iterative process

  19. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry`s R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI`s capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs.

  20. Total System Performance Assessment, 1993: An evaluation of the potential Yucca Mountain repository

    International Nuclear Information System (INIS)

    Andrews, R.W.; Dale, T.F.; McNeish, J.A.

    1994-03-01

    Total System Performance Assessments are an important component in the evaluation of the suitability of Yucca Mountain, Nevada as a potential site for a mined geologic repository for the permanent disposal of high-level radioactive wastes in the United States. The Total System Performance Assessments are conducted iteratively during site characterization to identify issues which should be addressed by the characterization and design activities as well as providing input to regulatory/licensing and programmatic decisions. During fiscal years 1991 and 1992, the first iteration of Total System Performance Assessment (hereafter referred to as TSPA 1991) was completed by Sandia National Laboratories and Pacific Northwest Laboratory. Beginning in fiscal year 1993, the Civilian Radioactive Waste Management System Management and Operating Contractor was assigned the responsibility to plan, coordinate, and contribute to the second iteration of Total System Performance Assessment (hereafter referred to as TSPA 1993). This document presents the objectives, approach, assumptions, input, results, conclusions, and recommendations associated with the Management and Operating Contractor contribution to TSPA 1993. The new information incorporated in TSPA 1993 includes (1) revised estimates of radionuclide solubilities (and their thermal and geochemical dependency), (2) thermal and geochemical dependency of spent fuel waste alteration and glass dissolution rates, (3) new distribution coefficient (k d ) estimates, (4) revised estimates of gas-phase velocities and travel times, and (5) revised hydrologic modeling of the saturated zone which provides updated estimates of the advective flux through the saturated zone

  1. Total System Performance Assessment, 1993: An evaluation of the potential Yucca Mountain repository

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, R.W.; Dale, T.F.; McNeish, J.A.

    1994-03-01

    Total System Performance Assessments are an important component in the evaluation of the suitability of Yucca Mountain, Nevada as a potential site for a mined geologic repository for the permanent disposal of high-level radioactive wastes in the United States. The Total System Performance Assessments are conducted iteratively during site characterization to identify issues which should be addressed by the characterization and design activities as well as providing input to regulatory/licensing and programmatic decisions. During fiscal years 1991 and 1992, the first iteration of Total System Performance Assessment (hereafter referred to as TSPA 1991) was completed by Sandia National Laboratories and Pacific Northwest Laboratory. Beginning in fiscal year 1993, the Civilian Radioactive Waste Management System Management and Operating Contractor was assigned the responsibility to plan, coordinate, and contribute to the second iteration of Total System Performance Assessment (hereafter referred to as TSPA 1993). This document presents the objectives, approach, assumptions, input, results, conclusions, and recommendations associated with the Management and Operating Contractor contribution to TSPA 1993. The new information incorporated in TSPA 1993 includes (1) revised estimates of radionuclide solubilities (and their thermal and geochemical dependency), (2) thermal and geochemical dependency of spent fuel waste alteration and glass dissolution rates, (3) new distribution coefficient (k{sub d}) estimates, (4) revised estimates of gas-phase velocities and travel times, and (5) revised hydrologic modeling of the saturated zone which provides updated estimates of the advective flux through the saturated zone.

  2. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    International Nuclear Information System (INIS)

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI's capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs

  3. Use of One-On Analysis to Evaluate Total System Performance of the Proposed Yucca Mountain Nuclear Waste Repository

    International Nuclear Information System (INIS)

    Saulnier, G.J. Jr.; Lee, K.P.; Mehta, S.; Sevougian, S.D.; Kalinich, D.; McNeish, J.A.

    2002-01-01

    The Yucca Mountain Site Characterization Project is currently evaluating the future performance of the proposed U.S. high-level nuclear waste repository. Using the Total System Performance Assessment (TSPA) model, a stylized analysis was conducted to evaluate the relative importance of natural and engineered barriers to movement of radionuclides from the proposed repository. These stylized ''one-on'' analyses consist of sequentially adding features, components, and processes, associated with the natural and engineered barriers, incorporated within the TSPA model and evaluating the effect of these elements on repository performance, as measured by the total mean annual dose to a reasonably maximally exposed individual. The analyses are ''stylized'' in the sense that they are performed to gain insight only. They are not meant to represent a real physical system in most cases, and in some cases allow the TSPA model to simulate results using parameter ranges outside the normal bounds of the TSPA model. In particular, the analyses provide insight into the relative contributions of repository features and processes in a way that is not possible using the full TSPA performance-assessment model. For example, in the nominal scenario of the TSPA model, the contribution of the natural system is masked by the contribution of the engineered system

  4. Sorption databases for the cementitious near-field of a L/ILW repository for performance assessment

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Sarott, F.A.

    1995-03-01

    Approximately 95% of the material in the L/ILW repository for short-lived low- and intermediate-level wastes consists of concrete; the remaining approx. 5% consists of steel (4%) and high molecular weight organic waste components (1%). Radionuclide sorption onto concrete represents one of the most important retardation mechanisms in the disposal caverns. This report compiles the sorption properties of hydrated cement, the most important sorbing material present in concrete, in the form of data sets for safety relevant nuclides under repository conditions; these data can then be used directly in performance assessment. Processes which affect sorption onto cement in the disposal caverns are documented in different data sets in this report. In this report, the distribution coefficients for radionuclides on cement are based to a large extent on values measured under repository-relevant conditions; this is true for cement without complexants in particular. (author) figs., tabs., refs

  5. Regulatory compliance for a Yucca Mountain Repository: A performance assessment perspective

    International Nuclear Information System (INIS)

    Dyer, J.R.; Van Luik, A.E.; Gil, A.V.; Brocoum, S.J.

    1997-01-01

    The U.S. Department of Energy's Yucca Mountain Site Characterization Project is scheduled to submit a License Application in the year 2002. The License Application is to show compliance with the regulations promulgated by the U.S. Nuclear Regulatory Commission which implement standards promulgated by the U.S. Environmental Protection Agency. These standards are being revised, and it is not certain what their exact nature will be in term of either the performance measure(s) or the time frames that are to be addressed. This paper provides some insights pertaining to this regulatory history, an update on Yucca Mountain performance assessments, and a Yucca Mountain Site Characterization Project perspective on proper standards based on Project experience in performance assessment for its proposed Yucca Mountain Repository system. The Project's performance assessment based perspective on a proper standard applicable to Yucca Mountain may be summarized as follows: a proper standard should be straight forward and understandable; should be consistent with other standards and regulations; and should require a degree of proof that is scientifically supportable in a licensing setting. A proper standard should have several attributes: (1) propose a reasonable risk level as its basis, whatever the quantitative performance measure is chosen to be, (2) state a definite regulatory time frame for showing compliance with quantitative requirements, (3) explicitly recognize that the compliance calculations are not predictions of actual future risks, (4) define the biosphere to which risk needs to be calculated in such a way as to constrain potentially endless speculation about future societies and future human actions, and (5) have as its only quantitative requirement the risk limit (or surrogate performance measure keyed to risk) for the total system

  6. SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models

    International Nuclear Information System (INIS)

    Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II.

    1992-09-01

    Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community

  7. In situ experiments on the performance of near-field for nuclear waste repository at KURT

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won-Jin, E-mail: wjcho@kaeri.re.kr [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Kim, Jin-Sub; Lee, Changsoo [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Kwon, Sangki [Inha University, Department of Energy Resources Engineering, 253 Yonghyun-dong, Nam-gu, Incheon 402-751 (Korea, Republic of); Choi, Jong-Won [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Results of in situ experiments on the near-field of a repository are summarized. Black-Right-Pointing-Pointer In BHT, the rock temperatures at 0.3 m from heater showed 40-50 Degree-Sign C increase. Black-Right-Pointing-Pointer EDZ size measured from the in situ test was in the range of 0.6-1.8 m. Black-Right-Pointing-Pointer Maximum errors in estimating the location of AE source were 0.6-1.0 m. Black-Right-Pointing-Pointer Permeability in the EDZ increased up to 2 orders compared with the intact rock. - Abstract: To obtain the information on the design and performance assessment of a geological repository for nuclear waste, several in situ experiments on the performance of the near-field have been conducted for 5 years in the small-scale underground research laboratory, KURT. This paper summarizes the results from the in situ experiments. In the borehole heater test, the rock temperature at 0.3 m distance from the heater hole with 90 Degree-Sign C showed a 40 Degree-Sign C increase over initial temperature. After heating with 120 Degree-Sign C, the rock temperature at 0.3 m distance from the heater hole increased up to 50 Degree-Sign C over initial temperature. The EDZ size measured from the in situ test was in the range of 0.6-1.8 m, and was higher than that from the laboratory tests, which was estimated to be around 1.1-1.5 m. The maximum errors in estimating the location of acoustic emission source were 1.0 m in EDZ and 0.6 m in an intact rock zone, respectively. The damping ratios of the EDZ and intact rock were 0.091 and 0.005, respectively. The permeability of rock increased with decreasing distance from the tunnel wall because of the EDZ. The permeability in the EDZ seems to be increased up to 2 orders compared with that in the intact rock.

  8. Microbial processes relevant for the long-term performance of radioactive waste repositories in clays

    International Nuclear Information System (INIS)

    Meleshyn, Artur

    2012-01-01

    Document available in extended abstract form only. A number of investigations on occurrence and viability of microbes in compacted clays have been aimed at studying possible microbial effects on long-term performance of a deep geological repository (DGR) for high-level radioactive waste (HLW) and spent nuclear fuel (SF). Compacted clays are considered in current DGR designs either as a buffer material or as a host rock. The primary purpose of the present work was to qualitatively evaluate the relevance of microbial activity for the long-term performance of a DGR and to identify which safety-relevant processes and properties can be potentially influenced by this activity. The present analysis identified eight clay properties essential for maintaining safety functions of containment and retardation of the disposal system - swelling pressure, specific surface area, cation exchange capacity, anion sorption capacity, porosity, permeability, fluid pressure, plasticity - which can potentially be influenced by microbial processes in clay buffer and Clay-stone within a DGR for HLW/SF. Iron(III)- and sulphate-reducing, fermentative, methane-producing and oxidizing microbes can be considered to be present in any clay formation. Each habitat includes a massive number of microbial niches with perhaps only a small proportion of the species being metabolically active at the habitat's conditions, the remainder becoming not extinct. Moreover, clays contain electron donors and electron acceptors in amounts sufficient for these microbes to remain active during very long periods of time. Additional sources of electron donors or electron acceptors will inevitably be added to the repository system as a result of DGR excavation, placement of radioactive waste as well as backfilling and sealing of the DGR. In no case should the potential impact of microbes be underestimated based on a possible argument of comparably low biomass of the microbes in contact with metal surfaces or dissolved

  9. Effects of heat from high-level waste on performance of deep geological repository components

    International Nuclear Information System (INIS)

    1984-11-01

    This report discusses the effects of heat on the deep geological repository systems and its different components. The report is focussed specifically on effects due to thermal energy release solely from high-level waste or spent fuel. It reviews the experimental data and theoretical models of the effects of heat both on the behaviour of engineered and natural barriers. A summary of the current status of research and repository development including underground test facilities is presented

  10. Uncertainty and sensitivity analysis for two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant: Disturbed conditions

    International Nuclear Information System (INIS)

    HELTON, JON CRAIG; BEAN, J.E.; ECONOMY, K.; GARNER, J.W.; MACKINNON, ROBERT J.; MILLER, JOEL D.; SCHREIBER, J.D.; VAUGHN, PALMER

    2000-01-01

    Uncertainty and sensitivity analysis results obtained in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are presented for two-phase flow in the vicinity of the repository under disturbed conditions resulting from drilling intrusions. Techniques based on Latin hypercube sampling, examination of scatterplots, stepwise regression analysis, partial correlation analysis and rank transformations are used to investigate brine inflow, gas generation repository pressure, brine saturation and brine and gas outflow. Of the variables under study, repository pressure and brine flow from the repository to the Culebra Dolomite are potentially the most important in PA for the WIPP. Subsequent to a drilling intrusion repository pressure was dominated by borehole permeability and generally below the level (i.e., 8 MPa) that could potentially produce spallings and direct brine releases. Brine flow from the repository to the Culebra Dolomite tended to be small or nonexistent with its occurrence and size also dominated by borehole permeability

  11. Spent fuel as a waste form: Data needs to allow long term performance assessment under repository disposal conditions

    International Nuclear Information System (INIS)

    Oversby, V.M.

    1986-12-01

    Performance assessment calculations are required for high level waste repositories for a period of 10,000 years. The Siting Guidelines require a comparison of sites following site characterization and prior to final site selection to be made over a 100,000 year period. To perform the required calculations, a detailed knowledge of the physical and chemical processes that affect waste form performance will be needed for each site. This paper will review the factors that affect the release of radionuclides from spent fuel under repository conditions, summarize our present state of knowledge, and suggest areas where more work is needed to support the performance assessment calculations. 17 refs., 5 figs., 3 tabs

  12. A Bayesian reliability approach to the performance assessment of a geological waste repository

    International Nuclear Information System (INIS)

    Flueck, J.A.; Singh, A.K.

    1992-01-01

    This paper discusses the task of selecting a suitable site for a high-level waste disposal repository (HLWR) which certainly is a complex one in that one must address both engineering and economic factors of the proposed facility and site as well as environmental, public health, safety, and sociopolitical factors. Acknowledging the complexity of the siting problem for a HLWR leads one to readily conclude that a formal analysis, including the use of a performance assessment model (PAM), is needed to assist the designated decision makers in their task of selecting a suitable site. The overall goal of a PAM is to aid the decision makers in making the best possible technical siting decision. For a number of reason, the authors believe that the combining of both Bayesian decision theory and reliability methodology provides the best approach to constructing a useful PAM for assisting in the siting of a HLWR. This combination allows one to formally integrate existing relevant information, professional judgement, and component model outputs to produce conditionally estimated probabilities for a decision tree approach to the radionuclide release problem of a proposed HLWR. If loss functions are available, this also allows one to calculate the expected costs or losses from possible radionuclide releases. This latter calculation may be very important in selecting the final site from among a number of alternative sites

  13. Performance of phosphoric acid activated montmorillonite as buffer materials for radioactive waste repository

    International Nuclear Information System (INIS)

    Wang, Tsing-Hai; Liu, Tsung-Ying; Wu, Ding-Chiang; Li, Ming-Hsu; Chen, Jiann-Ruey; Teng, Shi-Ping

    2010-01-01

    In this study, the performance of phosphoric acid activated montmorillonite (PAmmt) was evaluated by cesium ions adsorption experiments. The PAmmt samples were obtained by activating with 1, 3 and 5 mol L -1 of phosphoric acid, respectively under reflux for 3, 12, and 24 h. Experimental results demonstrated that the treatment of raw K-10 montmorillonite with phosphoric acid increased the materials' affinity for Cs uptake and no significant amount of suspension solids were produced. A relatively insignificant variation in the CEC value was observed. Furthermore, PAmmt also showed high adsorption selectivity toward Cs ions. The improved sorptive properties were mainly related to the increased surface area and the relatively higher surface charge density. Increased specific surface area was the resulted from partial decomposition of lamellar structure of mmt; while the higher surface charge density was caused by the protonation of octahedral Al-OH sites during the acid activation. Generally speaking, stronger acid concentration and longer activation times would produce relatively more decomposed PAmmt particles. However, as the activation exceeds 3 h, the precipitation of Si 4+ would passivate PAmmt against further acid attacks. Based upon our results, acid activation by phosphoric acid could produce PAmmt samples with high sorption capacity and selectivity, and good structural integrity, which are beneficial to be used at radioactive waste repository.

  14. Achieving transparency in the total system performance assessment of a potential high level radioactive waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Bailey, J.; Rickertsen, L.; Cotton, T.

    1999-01-01

    This paper has presented an approach to quantitative assessment of the degree of postclosure defense-in-depth provided by the reference system of the VA (Viability Assessment). This approach identifies principal barriers, assesses barriers for common uncertainty and failure mode, conducts barrier neutralization analyses, and evaluates overall defense-in-depth. The neutralization approach of step 3 is particularly useful in untangling the contributions of various barriers to the results calculated by performance assessments. In fact, it provides the only way of assessing the contribution of barriers that are fully redundant with one another. The approach has been applied to the VA reference system. It shows how the natural transport barriers contribute to performance of the system. Since their individual contributions are redundant, uncertainties in those individual contributions are reduced in importance. The analyses also suggest uncertainties common to both of these barriers are important to the safety assessment. Thus, the approach appears to be capable of determining the contribution of the principal barriers to system performance. The ability to use performance assessment to show not only how the repository system is expected to perform, but also how it achieves that performance, should contribute substantially towards providing needed transparency to the safety case for a geologic repository. It is also a valuable tool during the development of the repository design and associated safety case, by identifying areas in which performance would be enhanced by increased redundancy

  15. Impacts of seismic activity on long-term repository performance at Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.; Wilson, M.L.; Borns, D.J.; Arnold, B.W.

    1995-01-01

    Several effects of seismic activity on the release of radionuclides from a potential repository at Yucca Mountain are quantified. Future seismic events are predicted using data from the seismic hazard analysis conducted for the Exploratory Studies Facility (ESF). Phenomenological models are developed, including rockfall (thermal-mechanical and seismic) in unbackfilled emplacement drifts, container damage caused by fault displacement within the repository, and flow-path chance caused by changes in strain. Using the composite-porosity flow model (relatively large-scale, regular percolation), seismic events show little effect on total-system releases; using the weeps flow model (episodic pulses of flow in locally saturated fractures), container damage and flow-path changes cause over an order of magnitude increase in releases. In separate calculations using, more realistic representations of faulting, water-table rise caused by seismically induced changes in strain are seen to be higher than previously estimated by others, but not sufficient to reach a potential repository

  16. Performance Prediction for Large-Scale Nuclear Waste Repositories: Final Report

    International Nuclear Information System (INIS)

    Glassley, W E; Nitao, J J; Grant, W; Boulos, T N; Gokoffski, M O; Johnson, J W; Kercher, J R; Levatin, J A; Steefel, C I

    2001-01-01

    embodied in the code accurately represents the state-of-the-art in modeling these processes, and that the conceptualization of the models used in the simulations honors the primary processes that are controlling these systems. Application of the code to a wide range of important and strategic problems has been undertaken. Particularly significant are results obtained concerning the evolution of a potential high level nuclear waste repository at Yucca Mountain, Nevada. In these simulations, the results suggest that fluid movement and chemical changes will be such as to encourage solute transport around the sides of the waste emplacement tunnels, thus minimizing the potential for seepage of water and dissolved salts into the tunnels. The results also indicate that the short term response of the geological system to waste emplacement will be complex and rapid, and will be most readily detected below waste emplacement tunnels. A successful monitoring program of repository performance during the early stages of the operational period would thus benefit by coordinating design and execution of sampling strategies with a simulation tool such as NUFT-C. Such an approach would allow efficient and cost-effective sampling strategies, and would facilitate interpretation of what will surely be complex and massive data sets

  17. Geologic CO2 Sequestration: Predicting and Confirming Performance in Oil Reservoirs and Saline Aquifers

    Science.gov (United States)

    Johnson, J. W.; Nitao, J. J.; Newmark, R. L.; Kirkendall, B. A.; Nimz, G. J.; Knauss, K. G.; Ziagos, J. P.

    2002-05-01

    Reducing anthropogenic CO2 emissions ranks high among the grand scientific challenges of this century. In the near-term, significant reductions can only be achieved through innovative sequestration strategies that prevent atmospheric release of large-scale CO2 waste streams. Among such strategies, injection into confined geologic formations represents arguably the most promising alternative; and among potential geologic storage sites, oil reservoirs and saline aquifers represent the most attractive targets. Oil reservoirs offer a unique "win-win" approach because CO2 flooding is an effective technique of enhanced oil recovery (EOR), while saline aquifers offer immense storage capacity and widespread distribution. Although CO2-flood EOR has been widely used in the Permian Basin and elsewhere since the 1980s, the oil industry has just recently become concerned with the significant fraction of injected CO2 that eludes recycling and is therefore sequestered. This "lost" CO2 now has potential economic value in the growing emissions credit market; hence, the industry's emerging interest in recasting CO2 floods as co-optimized EOR/sequestration projects. The world's first saline aquifer storage project was also catalyzed in part by economics: Norway's newly imposed atmospheric emissions tax, which spurred development of Statoil's unique North Sea Sleipner facility in 1996. Successful implementation of geologic sequestration projects hinges on development of advanced predictive models and a diverse set of remote sensing, in situ sampling, and experimental techniques. The models are needed to design and forecast long-term sequestration performance; the monitoring techniques are required to confirm and refine model predictions and to ensure compliance with environmental regulations. We have developed a unique reactive transport modeling capability for predicting sequestration performance in saline aquifers, and used it to simulate CO2 injection at Sleipner; we are now

  18. 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.

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

    International Nuclear Information System (INIS)

    Banwart, S.

    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

  20. Methodology used for total system performance assessment of the potential nuclear waste repository at yucca mountain (USA)

    International Nuclear Information System (INIS)

    Devonec, E.; Sevougian, S.D.; Mattie, P.D.; Mcneish, J.A.; Mishra, S.

    2001-01-01

    The U.S. Department of Energy and its contractors are currently evaluating a site in Nevada (Yucca Mountain) for disposal of high-level radioactive waste from U.S. commercial nuclear plants and U.S. government-owned facilities. The suitability of the potential geologic repository is assessed, based on its performance in isolating the nuclear waste from the environment. Experimental data and models representing the natural and engineered barriers are combined into a Total System Performance Assessment (TSPA) model. Because of the uncertainty in the current data and in the future evolution of the total system, simulations follow a probabilistic approach. Multiple realization simulations using Monte Carlo analysis are conducted over time periods of up to one million years, which estimates a range of possible behaviors of the repository. In addition to the nominal scenario, other exposure scenarios include the possibility of disruptive events such as volcanic eruption or intrusion, or accidental human intrusion. Sensitivity to key uncertain processes is analyzed. The influence of stochastic variables on the TSPA model output is assessed by ''uncertainty importance analysis'', e.g., regression analysis and classification tree analysis. Further investigation of the impact of parameters and assumptions is conducted through ''one-off analysis'', which consists in fixing a parameter at a particular value, using an alternative conceptual model, or in making a different assumption. Finally, robustness analysis evaluates the performance of the repository when various natural or engineered barriers are assumed to be degraded. The objective of these analyses is to evaluate the performance of the potential repository system under conditions ranging from expected to highly unlikely, though physically possible conditions. (author)

  1. Methodology used for total system performance assessment of the potential nuclear waste repository at yucca mountain (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Devonec, E.; Sevougian, S.D.; Mattie, P.D.; Mcneish, J.A. [Duke Engineering and Services, Town Center Drive, Las Vegas (United States); Mishra, S. [Duke Engineering and Services, Austin, TX (United States)

    2001-07-01

    The U.S. Department of Energy and its contractors are currently evaluating a site in Nevada (Yucca Mountain) for disposal of high-level radioactive waste from U.S. commercial nuclear plants and U.S. government-owned facilities. The suitability of the potential geologic repository is assessed, based on its performance in isolating the nuclear waste from the environment. Experimental data and models representing the natural and engineered barriers are combined into a Total System Performance Assessment (TSPA) model. Because of the uncertainty in the current data and in the future evolution of the total system, simulations follow a probabilistic approach. Multiple realization simulations using Monte Carlo analysis are conducted over time periods of up to one million years, which estimates a range of possible behaviors of the repository. In addition to the nominal scenario, other exposure scenarios include the possibility of disruptive events such as volcanic eruption or intrusion, or accidental human intrusion. Sensitivity to key uncertain processes is analyzed. The influence of stochastic variables on the TSPA model output is assessed by ''uncertainty importance analysis'', e.g., regression analysis and classification tree analysis. Further investigation of the impact of parameters and assumptions is conducted through ''one-off analysis'', which consists in fixing a parameter at a particular value, using an alternative conceptual model, or in making a different assumption. Finally, robustness analysis evaluates the performance of the repository when various natural or engineered barriers are assumed to be degraded. The objective of these analyses is to evaluate the performance of the potential repository system under conditions ranging from expected to highly unlikely, though physically possible conditions. (author)

  2. Repository environmental parameters and models/methodologies relevant to assessing the performance of high-level waste packages in basalt, tuff, and salt

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, H.C.; Croff, A.G.; Griess, J.C.; Smith, F.J.

    1987-09-01

    This document provides specifications for models/methodologies that could be employed in determining postclosure repository environmental parameters relevant to the performance of high-level waste packages for the Basalt Waste Isolation Project (BWIP) at Richland, Washington, the tuff at Yucca Mountain by the Nevada Test Site, and the bedded salt in Deaf Smith County, Texas. Guidance is provided on the identify of the relevant repository environmental parameters; the models/methodologies employed to determine the parameters, and the input data base for the models/methodologies. Supporting studies included are an analysis of potential waste package failure modes leading to identification of the relevant repository environmental parameters, an evaluation of the credible range of the repository environmental parameters, and a summary of the review of existing models/methodologies currently employed in determining repository environmental parameters relevant to waste package performance. 327 refs., 26 figs., 19 tabs.

  3. Repository environmental parameters and models/methodologies relevant to assessing the performance of high-level waste packages in basalt, tuff, and salt

    International Nuclear Information System (INIS)

    Claiborne, H.C.; Croff, A.G.; Griess, J.C.; Smith, F.J.

    1987-09-01

    This document provides specifications for models/methodologies that could be employed in determining postclosure repository environmental parameters relevant to the performance of high-level waste packages for the Basalt Waste Isolation Project (BWIP) at Richland, Washington, the tuff at Yucca Mountain by the Nevada Test Site, and the bedded salt in Deaf Smith County, Texas. Guidance is provided on the identify of the relevant repository environmental parameters; the models/methodologies employed to determine the parameters, and the input data base for the models/methodologies. Supporting studies included are an analysis of potential waste package failure modes leading to identification of the relevant repository environmental parameters, an evaluation of the credible range of the repository environmental parameters, and a summary of the review of existing models/methodologies currently employed in determining repository environmental parameters relevant to waste package performance. 327 refs., 26 figs., 19 tabs

  4. Review of scenario selection approaches for performance assessment of high-level waste repositories and related issues

    International Nuclear Information System (INIS)

    Banano, E.J.; Baca, R.G.

    1995-08-01

    The selection of scenarios representing plausible realizations of the future conditions-with associated probabilities of occurrence-that can affect the long-term performance of a high-level radioactive waste (HLW) repository is the commonly used method for treating the uncertainty in the prediction of the future states of the system. This method, conventionally referred to as the ''scenario approach,'' while common is not the only method to deal with this uncertainty; other method ''ch as the environmental simulation approach (ESA), have also been proposed. Two of the difficulties with the scenario approach are the lack of uniqueness in the definition of the term ''scenario'' and the lack of uniqueness in the approach to formulate scenarios, which relies considerably on subjective judgments. Consequently, it is difficult to assure that a complete and unique set of scenarios can be defined for use in a performance assessment. Because scenarios are key to the determination of the long-term performance of the repository system, this lack of uniqueness can present a considerable challenge when attempting to reconcile the set of scenarios, and their level of detail, obtained using different approaches, particularly among proponents and regulators of a HLW repository

  5. Review of scenario selection approaches for performance assessment of high-level waste repositories and related issues.

    Energy Technology Data Exchange (ETDEWEB)

    Banano, E.J. [Beta Corporation International, Albuquerque, NM (United States); Baca, R.G. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1995-08-01

    The selection of scenarios representing plausible realizations of the future conditions-with associated probabilities of occurrence-that can affect the long-term performance of a high-level radioactive waste (HLW) repository is the commonly used method for treating the uncertainty in the prediction of the future states of the system. This method, conventionally referred to as the ``scenario approach,`` while common is not the only method to deal with this uncertainty; other method ``ch as the environmental simulation approach (ESA), have also been proposed. Two of the difficulties with the scenario approach are the lack of uniqueness in the definition of the term ``scenario`` and the lack of uniqueness in the approach to formulate scenarios, which relies considerably on subjective judgments. Consequently, it is difficult to assure that a complete and unique set of scenarios can be defined for use in a performance assessment. Because scenarios are key to the determination of the long-term performance of the repository system, this lack of uniqueness can present a considerable challenge when attempting to reconcile the set of scenarios, and their level of detail, obtained using different approaches, particularly among proponents and regulators of a HLW repository.

  6. SR-CAN - a safety assessment of a repository of spent nuclear fuel: canister performance and effects on the biosphere

    International Nuclear Information System (INIS)

    Kautsky, U.; Kumblad, L.

    2004-01-01

    During the next few years the Swedish Nuclear Fuel and Waste Management Co. (SKB) performs site investigations at two sites in Sweden for a future repository of spent nuclear fuel. Parallel an encapsulation plant is planned to encapsulate the spent fuel in copper canisters according to the KBS-3 method. The purpose of the SR-CAN safety assessment is to show the performance of the canister isolations at different sites for a repository at 500 meters depth in crystalline rock. Moreover, SR-CAN provides an example how the site specific safety assessment of a deep repository will be made in year 2006-2008. To be able to calculate dose and risk for humans and the environment, new assessment methods were developed for the biosphere. These methods were based on a system ecological approach and used knowledge from landscape ecology to provide an integrated approach with hydrology and geology considering the discharges in a watershed and calculating consequences in terrestrial and aquatic (freshwater and marine) ecosystems. A range of methods and tools were developed in GIS and Matlab/Simulink to be able to model and understand the important processes in the landscape today and during the next few thousands of years. In this paper, an overview of the program and the novel methods are presented, as well as some examples from performance calculations from a watershed in the Forsmark area considering effects on humans and ecosystems. (author)

  7. A new approach to performance assessment of barriers in a repository. Executive summary, draft, technical appendices. Final report

    International Nuclear Information System (INIS)

    Mueller-Hoeppe, N.; Krone, J.; Niehues, N.; Poehler, M.; Raitz von Frentz, R.; Gauglitz, R.

    1999-06-01

    Multi-barrier systems are accepted as the basic approach for long term environmental safe isolation of radioactive waste in geological repositories. Assessing the performance of natural and engineered barriers is one of the major difficulties in producing evidence of environmental safety for any radioactive waste disposal facility, due to the enormous complexity of scenarios and uncertainties to be considered. This report outlines a new methodological approach originally developed basically for a repository in salt, but that can be transferred with minor modifications to any other host rock formation. The approach is based on the integration of following elements: (1) Implementation of a simple method and efficient criteria to assess and prove the tightness of geological and engineered barriers; (2) Using the method of Partial Safety Factors in order to assess barrier performance at certain reasonable level of confidence; (3) Integration of a diverse geochemical barrier in the near field of waste emplacement limiting systematically the radiological consequences from any radionuclide release in safety investigations and (4) Risk based approach for the assessment of radionuclide releases. Indicative calculations performed with extremely conservative assumptions allow to exclude any radiological health consequences from a HLW repository in salt to a reference person with a safety level of 99,9999% per year. (orig.)

  8. 10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

    Science.gov (United States)

    2010-01-01

    ... closure. (a) The geologic repository must include multiple barriers, consisting of both natural barriers... in combination with natural barriers, radiological exposures to the reasonably maximally exposed... engineered barrier system must be designed so that, working in combination with natural barriers, releases of...

  9. Initial demonstration of the NRC`s capability to conduct a performance assessment for a High-Level Waste Repository

    Energy Technology Data Exchange (ETDEWEB)

    Codell, R.; Eisenberg, N.; Fehringer, D.; Ford, W.; Margulies, T.; McCartin, T.; Park, J.; Randall, J.

    1992-05-01

    In order to better review licensing submittals for a High-Level Waste Repository, the US Nuclear Regulatory Commission staff has expanded and improved its capability to conduct performance assessments. This report documents an initial demonstration of this capability. The demonstration made use of the limited data from Yucca Mountain, Nevada to investigate a small set of scenario classes. Models of release and transport of radionuclides from a repository via the groundwater and direct release pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year simulation time. Latin hypercube sampling of input parameters was used to express results as distributions and to investigate model sensitivities. This methodology demonstration should not be interpreted as an estimate of performance of the proposed repository at Yucca Mountain, Nevada. By expanding and developing the NRC staff capability to conduct such analyses, NRC would be better able to conduct an independent technical review of the US Department of Energy (DOE) licensing submittals for a high-level waste (HLW) repository. These activities were divided initially into Phase 1 and Phase 2 activities. Additional phases may follow as part of a program of iterative performance assessment at the NRC. The NRC staff conducted Phase 1 activities primarily in CY 1989 with minimal participation from NRC contractors. The Phase 2 activities were to involve NRC contractors actively and to provide for the transfer of technology. The Phase 2 activities are scheduled to start in CY 1990, to allow Sandia National Laboratories to complete development and transfer of computer codes and the Center for Nuclear Waste Regulatory Analyses (CNWRA) to be in a position to assist in the acquisition of the codes.

  10. Evaluation of repository safety

    Energy Technology Data Exchange (ETDEWEB)

    Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S. [Center for Nuclear Waste Regulatory Analyses, San Antonio (United States)

    2002-07-01

    The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes

  11. Evaluation of repository safety

    International Nuclear Information System (INIS)

    Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S.

    2002-01-01

    The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes

  12. Potential impact of Andrassy bentonite microbial diversity in the long-term performance of a deep nuclear waste repository

    Science.gov (United States)

    Tadza, M. Y. Mohd; Tadza, M. A. Mohd; Bag, R.; Harith, N. S. H.

    2018-01-01

    Copper and steel canning and bentonite buffer are normally forseen as the primary containment component of a deep nuclear waste repository. Distribution of microbes in subsurface environments have been found to be extensive and directly or indirectly may exert influence on waste canister corrosion and the mobility of radionuclides. The understanding of clays and microbial interaction with radionuclides will be useful in predicting the microbial impacts on the performance of the waste repositories. The present work characterizes the culture-dependent microbial diversity of Andrassy bentonite recovered from Tawau clay deposits. The evaluation of microbial populations shows the presence of a number of cultivable microbes (e.g. Staphylococcus, Micrococcus, Achromobacter, Bacillus, Paecilomyces, Trichoderma, and Fusarium). Additionally, a pigmented yeast strain Rhodotorula mucilaginosa was also recovered from the formation. Both Bacillus and Rhodotorula mucilaginosa have high tolerance towards U radiation and toxicity. The presence of Rhodotorula mucilaginosa in Andrassy bentonite might be able to change the speciation of radionuclides (e.g. uranium) in a future deep repository. However, concern over the presence of Fe (III) reduction microbes such as Bacillus also found in the formation could lead to corrosion of copper steel canister and affect the overall performance of the containment system.

  13. Methodology Used for Total System Performance Assessment of the Potential Nuclear Waste Repository at Yucca Mountain (USA)

    International Nuclear Information System (INIS)

    E. Devibec; S.D. Sevougian; P.D. Mattie; J.A. McNeish; S. Mishra

    2001-01-01

    The U.S. Department of Energy and its contractors are currently evaluating a site in Nevada (Yucca Mountain) for disposal of high-level radioactive waste from U.S. commercial nuclear plants and U.S. government-owned facilities. The suitability of the potential geologic repository is assessed, based on its performance in isolating the nuclear waste from the environment. Experimental data and models representing the natural and engineered barriers are combined into a Total System Performance Assessment (TSPA) model [1]. Process models included in the TSPA model are unsaturated zone flow and transport, thermal hydrology, in-drift geochemistry, waste package degradation, waste form degradation, engineered barrier system transport, saturated zone flow and transport, and biosphere transport. Because of the uncertainty in the current data and in the future evolution of the total system, simulations follow a probabilistic approach. Multiple realization simulations using Monte Carlo analysis are conducted over time periods of up to one million years, which estimates a range of possible behaviors of the repository. The environmental impact is measured primarily by the annual dose received by an average member of a critical population group residing 20 km down-gradient of the potential repository. In addition to the nominal scenario, other exposure scenarios include the possibility of disruptive events such as volcanic eruption or intrusion, or accidental human intrusion. Sensitivity to key uncertain processes is analyzed. The influence of stochastic variables on the TSPA model output is assessed by ''uncertainty importance analysis'', e.g., regression analysis and classification tree analysis. Further investigation of the impact of parameters and assumptions is conducted through ''one-off analysis'', which consists in fixing a parameter at a particular value, using an alternative conceptual model, or in making a different assumption. Finally, robustness analysis evaluates

  14. Plant data evaluation of performance confirmation test in HTTR after Tohoku-Pacific Ocean Earthquake

    International Nuclear Information System (INIS)

    Ono, Masato; Tochio, Daisuke; Shinohara, Masanori; Shimazaki, Yosuke; Yanagi, Shunki; Iigaki, Kazuhiko

    2012-03-01

    Tohoku-Pacific Ocean Earthquake occurred on March 11th 2011 and the earthquake intensity of an upper 5 on the Japanese scale was observed in Oarai town. HTTR conducted the confirmation test on cold state in order to ensure the facilities/instruments of reactor building operate normally. In this test, the plant data in the facilities/instruments start-up phase and continue steady operation phase were measured and compared with the previous operation data, and the soundness of facilities/instruments is evaluated. As a result, in after the earthquake, the facilities/instruments operate normally and the reactor cooling function of the HTTR were ensured. (author)

  15. Plant data evaluation of performance confirmation test in HTTR after Tohoku-Pacific Ocean Earthquake

    International Nuclear Information System (INIS)

    Ono, Masato; Tochio, Daisuke; Shinohara, Masanori; Shimazaki, Yosuke; Yanagi, Shunki; Iigaki, Kazuhiko

    2012-01-01

    Tohoku-Pacific Ocean Earthquake occurred on March 11th 2011 and the earthquake intensity of an upper 5 on the Japanese scale was observed in Oarai town. HTTR conducted the confirmation test on cold state in order to ensure the facilities/instruments of reactor building operate normally. In this test, the plant data in the facilities/instruments start-up phase and continue steady operation phase were measured and compared with the previous operation data, and the soundness of facilities/instruments is evaluated. As a result, in after the earthquake, the facilities/instruments operate normally and the reactor cooling function of the HTTR were ensured. (author)

  16. LISA: A performance assessment code for geological repositories of radioactive waste

    International Nuclear Information System (INIS)

    Bertozzi, G.; Saltelli, A.

    1985-01-01

    LISA, developed at JRC-Ispra, is a statistical code, which calculates the radiation exposures and risks associated with radionuclide releases from geological repositories of nuclear waste. The assessment methodology is described briefly. It requires that a number of probabilistic components be quantified and introduced in the analysis; the results are thus expressed in terms of risk. The subjective judgment of experts may be necessary to quantify the probabilities of occurrence of rare geological events. Because of large uncertainties in input data, statistical treatment of the Monte Carlo type is utilized for the analysis; thus, the output from LISA is obtained in the form of distributions. A few results of an application to a probabilistic scenario for a repository mined in a clay bed are illustrated

  17. Sample performance assessment of a high-level radioactive waste repository: sensitivity analysis

    International Nuclear Information System (INIS)

    Tkaczyk, A.

    2001-01-01

    The Yucca Mountain Project (YMP) is the USA's first attempt at long-term storage of High-Level Radioactive Waste (HLW). In theory, the reasoning for such a repository seems sound. In practice, there are many scenarios and cases to be considered while putting such a project into effect. Since a goal of YMP is to minimize dangers associated with long-term storage of HLW, it is important to estimate the dose rate to which current and future generations will be subjected. The lifetime of the repository is simulated to indicate the radiation dose rate to the maximally exposed individual; it is assumed that if the maximally exposed individual would not be harmed by the annual dose, the remaining population will be at even smaller risk. The determination of what levels of exposure can be deemed harmless is a concern, and the results from the simulations as compared against various regulations are discussed. (author)

  18. Sample performance assessment of a high-level radioactive waste repository: sensitivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, A. [Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Mechanical Engineering

    2001-07-01

    The Yucca Mountain Project (YMP) is the USA's first attempt at long-term storage of High-Level Radioactive Waste (HLW). In theory, the reasoning for such a repository seems sound. In practice, there are many scenarios and cases to be considered while putting such a project into effect. Since a goal of YMP is to minimize dangers associated with long-term storage of HLW, it is important to estimate the dose rate to which current and future generations will be subjected. The lifetime of the repository is simulated to indicate the radiation dose rate to the maximally exposed individual; it is assumed that if the maximally exposed individual would not be harmed by the annual dose, the remaining population will be at even smaller risk. The determination of what levels of exposure can be deemed harmless is a concern, and the results from the simulations as compared against various regulations are discussed. (author)

  19. The impact of repository heat on thermo-hydrological performance at Yucca Mountain

    International Nuclear Information System (INIS)

    Buscheck, T.A.; Nitao, J.J.

    1993-09-01

    To safely and permanently store high-level nuclear waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact a waste package (WP), accelerate its failure rate, and eventually transport radionuclides to the water table. These analyses have demonstrated that the only significant source of liquid water is nonequilibrium fracture flow from: (1) meteoric sources, (2) condensate drainage generated under boiling conditions, and (3) condensate drainage generated under sub-boiling conditions. The first source of liquid water arises from the ambient system; the second and third sources are generated by repository heat. Buoyant vapor flow, occurring either on a sub-repository scale or on a mountain scale, may play an important role in the generation of the second and third sources of liquid water. By considering a wide range in bulk permeability, k b , the authors identify the threshold k b (called k b hyd ) at which buoyant, vapor convection begins to dominate hydrological behavior, and the threshold k b (called k b th ) at which this convection begins to dominate thermal behavior. They find that k b th is generally an order of magnitude larger than k b hyd and that the development of a large above-boiling zone suppresses the effects of buoyant vapor flow. Of particular concern are conditions that promote the focusing of vapor flow and condensate drainage, which could result in persistent two-phase conditions (often referred to as the heat-pipe effect) in the vicinity of WPs. The results of this study underscore the need for in situ heater tests to help diagnose the potential for the major repository-heat-driven sources of fracture flow

  20. Radioactive waste isolation in salt: special advisory report on the status of the Office of Nuclear Waste Isolation's plans for repository performance assessment

    International Nuclear Information System (INIS)

    Ditmars, J.D.; Walbridge, E.W.; Rote, D.M.; Harrison, W.; Herzenberg, C.L.

    1983-10-01

    Repository performance assessment is analysis that identifies events and processes that might affect a repository system for isolation of radioactive waste, examines their effects on barriers to waste migration, and estimates the probabilities of their occurrence and their consequences. In 1983 Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) prepared two plans - one for performance assessment for a waste repository in salt and one for verification and validation of performance assessment technology. At the request of the US Department of Energy's Salt Repository Project Office (SRPO), Argonne National Laboratory reviewed those plans and prepared this report to advise SRPO of specific areas where ONWI's plans for performance assessment might be improved. This report presents a framework for repository performance assessment that clearly identifies the relationships among the disposal problems, the processes underlying the problems, the tools for assessment (computer codes), and the data. In particular, the relationships among important processes and 26 model codes available to ONWI are indicated. A common suggestion for computer code verification and validation is the need for specific and unambiguous documentation of the results of performance assessment activities. A major portion of this report consists of status summaries of 27 model codes indicated as potentially useful by ONWI. The code summaries focus on three main areas: (1) the code's purpose, capabilities, and limitations; (2) status of the elements of documentation and review essential for code verification and validation; and (3) proposed application of the code for performance assessment of salt repository systems. 15 references, 6 figures, 4 tables

  1. Treatment of uncertainty in the US department of energy's yucca mountain repository total system performance assessment (TSPA)

    International Nuclear Information System (INIS)

    Van Luik, A.; Zwahlen, E.

    2004-01-01

    The regulatory requirements being addressed in the US geological repository programme for spent nuclear fuel and high-level waste specify that performance assessment is to be used to address probabilistically defined mean-value dose constraints. Dose was chosen as the preferred performance measure because an acceptable dose limit could be selected through the regulation-setting process, based on a defined acceptable risk. By setting a dose limit, arguments about the conversion of a potential dose to a potential risk was taken off the table as a potential licensing issue. However, the probabilistic approach called for actually delivers a 'risk of a dose', a risk of a potential given dose value to a hypothetical person living at a set distance from the repository, with a set lifestyle, between the time of permanent closure and 10 000 years. Analyses must also be shown for the peak dose if it occurs after 10 000 years, essentially to a million years. For uncertain parameters that are important to system performance, the goal is to present an analysis that, in accord with applicable regulation, focuses on the mean value of the performance measure but also explores the 'full range of defensible and reasonable parameter distributions'.... System performance evaluations should not be unduly influenced by... 'extreme physical situations and parameter values'. These disclosure requirements are to be met by showing a range of potential outcomes and designating the mean value within that range. (author)

  2. Geochemical performance of earthen and cementitious sealing materials for radioactive waste repositories

    International Nuclear Information System (INIS)

    Melchoir, D.; Glazier, R.; Marton, R.

    1988-01-01

    Earthen and cementitious materials are proposed as part of the sealing system for radioactive waste repositories. Compacted clay-bearing earthen materials could be used in sealing shafts and shaft entryways; and in the waste emplacement boundary areas in some repository designs. Earthen material mixtures are being considered because they can be engineered and emplaced to achieve low permeabilities, appropriate swelling characteristics, and adequate strength with little tendency to degrade during changing environmental conditions. The proposed earthen sealing materials include sodium and calcium mont-morillonites, illites, and mixtures with graded aggregates of sand. To assess the relative advantages and disadvantages of various pure and mixed materials, important geochemical processes (e.g., ion-exchange, phase transformation, dissolution, and precipitation of secondary minerals) need to be evaluated. These processes could impact seal integrity by changing permeability and/or mineral swell potential. Hydrous calcium-silicate-based cementitious materials such as grouts or concrete might also be used in some proposed sealing systems

  3. The impact of thermal loading on repository performance at Yucca Mountain

    International Nuclear Information System (INIS)

    Buscheck, T.A.; Nitao, J.J.

    1992-01-01

    In the unsaturated zone at Yucca Mountain, liquid flow along preferential fracture pathways is the only credible mechanism capable of bringing water to waste packages and transporting radionuclide to the water table. Three categories of features or mechanisms will mitigate the impact of flow along preferential fracture pathways: (1) discontinuity in fracture pathways, (2) liquid-phase dispersion in fracture networks, and (3) fracture-matrix interaction. For repository areal power densities (APDs) that are too low to result in significant boiling or rock dry-out effects, the primary mode of fracture-matrix interaction is matrix imbibition. For high APDs, boiling and enhanced matrix imbibition due to rock dry-out significantly add to the capacity of the unsaturated zone to retard fracture-dominated flow. With the use of V-TOUGH code, hydrothermal flow calculations are made for a range of APDs and spent fuel ages. For APD > 20 kW/acre, repository-heat-generated flow of vapor and liquid in fractures is found to dominate the ambient hydrological system. For high APDs, boiling conditions can persist for 10,000 yr or longer and rock-dry benefits for at least 100,000 yr

  4. Coupled processes in repository sealing

    International Nuclear Information System (INIS)

    Case, J.B.; Kelsall, P.C.

    1985-01-01

    The significance of coupled processes in repository sealing is evaluated. In most repository designs, shaft seals will be located in areas of relatively low temperature perturbation, in which case the coupling of temperature with stress and permeability may be less significant than the coupling between stress and permeability that occurs during excavation. Constitutive relationships between stress and permeability are reviewed for crystalline rock and rocksalt. These provide a basis for predicting the development of disturbed zones near excavations. Field case histories of the degree of disturbance are presented for two contrasting rock types - Stripa granite and Southeastern New Mexico rocksalt. The results of field investigations in both rock types confirm that hydraulic conductivity or permeability is stress dependent, and that shaft seal performance may be related to the degree that stresses are perturbed and restored near the seal

  5. MAJOR REPOSITORY DESIGN ISSUES

    International Nuclear Information System (INIS)

    JACK N. BAILEY, DWAYNE CHESTNUT, JAMES COMPTON AND RICHARD D. SNELL

    1997-01-01

    The Yucca Mountain Project is focused on producing a four-part viability assessment in late FY98. Its four components (design, performance assessment, cost estimate, and licensing development plan) must be consistent. As a tool to compare design and performance assessment options, a series of repository pictures were developed for the sequential time phases of a repository. The boundaries of the time phases correspond to evolution in the engineered barrier system (EBS)

  6. Development of models for use in the assessment of waste repository performance

    International Nuclear Information System (INIS)

    Dickson, A.G.; Weare, J.H.

    1989-01-01

    Any repository suitable for the disposal of radioactive waste comprises a combination of various man-made and natural barriers which aim to prevent transfer of the radionuclides from the canister to the external environment. Our group has developed the techniques needed to model the equilibrium chemistry of complex multicomponent rock/water systems over a range of ionic strengths and temperatures. These models, show remarkable agreement with field measurements when applied to natural systems. They have been applied successfully to interpret a variety of geochemical processes: studies of ancient and modern marine evaporite systems, studies of the solar evaporation of seawater studies of mineral formation in lakes and in fluid inclusions. At present our models are limited to the components of the seawater system (Na + , Mg 2+ , Ca 2+ , H + , SO 4 2- , HCO 3 - , CO 3 2- , CO 2 ), together with the borate species and SiO 2 . 2 tabs

  7. The impact of thermal loading on repository performance at Yucca Mountain

    International Nuclear Information System (INIS)

    Buscheck, T.A.; Nitao, J.J.

    1992-01-01

    This paper reports that in the unsaturated zone at Yucca Mountain, liquid flow along preferential fracture pathways is the only credible mechanism capable of bringing water to waste packages and transporting radionuclides to the water table. Three categories of features or mechanisms will mitigate the impact of flow along preferential fracture pathways: discontinuity in fracture pathways, liquid-phase dispersion in fracture networks, and fracture-matrix interaction. For repository areal power densities (APDs) that are too low to result in significant boiling or rock dry-out effects, the primary mode of fracture-matrix interaction is matrix imbibition. For high APDs, boiling and enhanced matrix imbibition due to rock dry-out significantly add to the capacity of the unsaturated zone to retard fracture-dominated flow

  8. A methodology of uncertainty/sensitivity analysis for PA of HLW repository learned from 1996 WIPP performance assessment

    International Nuclear Information System (INIS)

    Lee, Y. M.; Kim, S. K.; Hwang, Y. S.; Kang, C. H.

    2002-01-01

    The WIPP (Waste Isolation Pilot Plant) is a mined repository constructed by the US DOE for the permanent disposal of transuranic (TRU) wastes generated by activities related to defence of the US since 1970. Its historical disposal operation began in March 1999 following receipt of a final permit from the State of NM after a positive certification decision for the WIPP was issued by the EPA in 1998, as the first licensed facility in the US for the deep geologic disposal of radioactive wastes. The CCA (Compliance Certification Application) for the WIPP that the DOE submitted to the EPA in 1966 was supported by an extensive Performance Assessment (PA) carried out by Sandia National Laboratories (SNL), with so-called 1996 PA. Even though such PA methodologies could be greatly different from the way we consider for HLW disposal in Korea largely due to quite different geologic formations in which repository are likely to be located, a review on lots of works done through the WIPP PA studies could be the most important lessons that we can learn from in view of current situation in Korea where an initial phase of conceptual studies on HLW disposal has been just started. The objective of this work is an overview of the methodology used in the recent WIPP PA to support the US DOE WIPP CCA ans a proposal for Korean case

  9. Effects of silica redistribution on performance of high-level nuclear waste repositories in saturated geologic formations

    International Nuclear Information System (INIS)

    Verma, A.; Pruess, K.

    1985-11-01

    Evaluation of the thermohydrological conditions near high-level waste packages is needed for the design of the waste canister and for overall repository design and performance assessment. Most available studies in this area have assumed that the hydrologic properties of the host rock do not change in response to the thermal, mechanical or chemical effects caused by waste emplacement. However, the ramifications of this simplifying assumption have not been substantiated. We have studied dissolution and precipitation of silica in thermally driven flow systems, including changes in formation porosity and permeability. Using numerical simulation, we compare predictions of thermohydrological conditions with and without inclusion of silica redistribution effects. Two cases were studied, namely, a canister-scale problem, a repository-wide thermal convection problem, and different pore models were employed for the permeable medium (fractures with uniform or non-uniform cross sections). We find that silica redistribution generally has insignificant effects on host rock and canister temperatures, pore pressures, or flow velocites

  10. Iterative performance assessments as a regulatory tool for evaluating repository safety: How experiences from SKI Project-90 were used in formulating the new performance assessment project SITE-94

    International Nuclear Information System (INIS)

    Andersson, J.

    1993-01-01

    The Swedish Nuclear Power Inspectorate, SKI, regulatory research program has to prepare for the process of licensing a repository for spent nuclear fuel, by building up the necessary knowledge and review capacity. SKIs main strategy for meeting this demand is to develop an independent performance assessment capability. SKIs first own performance assessment project, Project-90, was completed in 1991 and is now followed by a new project, SITE-94. SITE-94 is based on conclusions reached within Project-90. An independent review of Project-90, carried out by a NEA team of experts, has also contributed to the formation of the project. Another important reason for the project is that the implementing organization in Sweden, SKB, has proposed to submit an application to start detailed investigation of a repository candidate site around 1997. SITE-94 is a performance assessment of a hypothetical repository at a real site. The main objective of the project is to determine how site specific data should be assimilated into the performance assessment process, and to evaluate how uncertainties inherent in site characterization will influence performance assessment results. This will be addressed by exploring multiple interpretations, conceptual models, and parameters consistent with the site data. The site evaluation will strive for consistency between geological, hydrological, rock mechanical, and geochemical descriptions. Other important elements of SITE-94 are the development of a practical and defensible methodology for defining, constructing and analyzing scenarios, the development of approaches for treatment of uncertainties, evaluation of canister integrity, and the development and application of an appropriate quality assurance plan for performance assessments

  11. Modeling The Inhalation Exposure Pathway In Performance Assessment Of Geologic Radioactive Waste Repository At Yucca Mountain

    International Nuclear Information System (INIS)

    M.A. Wasiolek

    2006-01-01

    Inhalation exposure pathway modeling has recently been investigated as one of the tasks of the BIOPROTA Project (BIOPROTA 2005). BIOPROTA was set up to address the key uncertainties in long term assessments of contaminant releases into the environment arising from radioactive waste disposal. Participants of this international Project include national authorities and agencies, both regulators and operators, with responsibility for achieving safe and acceptable radioactive waste management. The objective of the inhalation task was to investigate the calculation of doses arising from inhalation of particles suspended from soils within which long-lived radionuclides, particularly alpha emitters, had accumulated. It was recognized that site-specific conditions influence the choice of conceptual model and input parameter values. Therefore, one of the goals of the task was to identify the circumstances in which different processes included in specific inhalation exposure pathway models were important. This paper discusses evaluation of processes and modeling assumptions specific to the proposed repository at Yucca Mountain as compared to the typical approaches and other models developed for different assessments and project specific contexts. Inhalation of suspended particulates that originate from contaminated soil is an important exposure pathway, particularly for exposure to actinides such as uranium, neptunium and plutonium. Radionuclide accumulation in surface soil arises from irrigation of soil with contaminated water over many years. The level of radionuclide concentration in surface soil depends on the assumed duration of irrigation. Irrigation duration is one of the parameters used on biosphere models and it depends on a specific assessment context. It is one of the parameters addressed in this paper from the point of view of assessment context for the proposed repository at Yucca Mountain. The preferred model for the assessment of inhalation exposure uses

  12. Migration case studies and the implications of humic substances for the radiological performance assessment of radioactive waste repositories

    International Nuclear Information System (INIS)

    Bryan, N.D.; Bernhard, G.; Geipel, G.; Heise, K.H.; Schmeide, K.; Benes, P.

    2005-01-01

    Using the information obtained during the experimental and modelling tasks a series of migration case studies have been performed. These are not full performance assessment studies, but are merely intended to demonstrate the likely impact of humic substances upon the migration of radionuclides in the environment. Three separate sites have been investigated: (i) a shallow waste repository site at Dukovany in the Czech Republic; (ii) the formerly proposed, but now withdrawn, waste repository site at Gorleben in Germany; (iii) a large rock pile, consisting of tailings from a uranium mine, Schlema Alberode, near Dresden, Germany. To provide the maximum information, a variety of 'release scenarios' have been defined: continuous leakage in the Dukovany case study; a short pulsed release at Gorleben, and steady leaching in the case of the rock pile. The effects of the magnitudes of the chemical rate constants have been studied along with the effects of the initial distribution between exchangeable and non-exchangeable. Further, modelling during the HUPA project has shown that in certain lab column experiments the sorption of humic and humic-radionuclide complexes onto mineral surfaces could have an impact upon migration. Therefore, the likely impact of these processes on the field scale was investigated. In each of the three cases, humics are predicted to have a significant impact upon migration. However, whereas for the repository cases, it is the presence of the non-exchangeable fraction that results in migration, and the exchangeable fraction plays no significant part in transport, for the rock pile, the model predicts that the humic should promote migration even with the exchangeable interaction alone. Humic sorption may affect the degree of migration, but even in the case of maximum impact, the net effect of humic substances is still to enhance migration significantly. In fact, the initial distribution of radionuclide upon entry to the far-field is much more

  13. Repository Integration Program: RIP performance assessment and strategy evaluation model theory manual and user`s guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This report describes the theory and capabilities of RIP (Repository Integration Program). RIP is a powerful and flexible computational tool for carrying out probabilistic integrated total system performance assessments for geologic repositories. The primary purpose of RIP is to provide a management tool for guiding system design and site characterization. In addition, the performance assessment model (and the process of eliciting model input) can act as a mechanism for integrating the large amount of available information into a meaningful whole (in a sense, allowing one to keep the ``big picture`` and the ultimate aims of the project clearly in focus). Such an integration is useful both for project managers and project scientists. RIP is based on a `` top down`` approach to performance assessment that concentrates on the integration of the entire system, and utilizes relatively high-level descriptive models and parameters. The key point in the application of such a ``top down`` approach is that the simplified models and associated high-level parameters must incorporate an accurate representation of their uncertainty. RIP is designed in a very flexible manner such that details can be readily added to various components of the model without modifying the computer code. Uncertainty is also handled in a very flexible manner, and both parameter and model (process) uncertainty can be explicitly considered. Uncertainty is propagated through the integrated PA model using an enhanced Monte Carlo method. RIP must rely heavily on subjective assessment (expert opinion) for much of its input. The process of eliciting the high-level input parameters required for RIP is critical to its successful application. As a result, in order for any project to successfully apply a tool such as RIP, an enormous amount of communication and cooperation must exist between the data collectors, the process modelers, and the performance. assessment modelers.

  14. Repository simulation tests

    International Nuclear Information System (INIS)

    Wicks, G.G.; Bibler, N.E.; Jantzen, C.M.; Plodinec, M.J.

    1984-01-01

    The repository simulation experiments described in this paper are designed to assess the performance of SRP waste glass under the most realistic repository conditions that can be obtained in the laboratory. These tests simulate the repository environment as closely as possible and introduce systematically the variability of the geology, groundwater chemistry, and waste package components during the leaching of the waste glass. The tests evaluate waste form performance under site-specific conditions, which differ for each of the geologic repositories under consideration. Data from these experiments will aid in the development of a realistic source term that can describe the release of radionuclides from SRP waste glass as a component of proposed waste packages. Hence, this information can be useful to optimize waste package design for SRP waste glass and to provide data for predicting long-term performance and subsequent conformance to regulations. The repository simulation tests also help to bridge the gap in interpreting results derived from tests performed under the control of the laboratory to the uncertainity and variability of field tests. In these experiments, site-specific repository components and conditions are emphasized and only the site specific materials contact the waste forms. An important feature of these tests is that both actual and simulated waste glasses are tested identically. 7 figures, 2 tables

  15. Repositories; Repositorios

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Carolina Braccini; Tello, Cledola Cassia Oliveira de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mails: cbf@cdtn.br; tellocc@cdtn.br

    2007-11-15

    The use of the nuclear energy is increasing in all areas. Then the radioactive waste management is in continuous development to comply the national and international established requirements. The final objective is to assure that it will not have any contamination of the public or the environmental, and that the exposition doses will be lower than the radiological protection limits. The multi barrier concept for the repository is internationally recognized. Among the repository types, the most used are: near surface, geological formations and of deposition in rock cavities. This article explains the concept and the types of repository and gives some examples of them. (author)

  16. Influence of temperature elevation on the sealing performance of a potential buffer material for a high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Cho, W.-J.; Lee, J.-O.; Kang, C.-H.

    2000-01-01

    The sealing performance of buffer material in a high-level waste repository depends largely upon the hydraulic conductivity, the swelling pressure, and the dissolution of organic carbon in the buffer material. Temperature effects on these properties were evaluated. The hydraulic conductivity and the swelling pressure of compacted bentonite increase with increasing temperature, but the effect of temperature elevation is not large. The dissolution of organic carbon in bentonite also increases with increasing temperature, but the resultant aqueous concentrations of organic carbon in bentonite suspensions are less than those of deep groundwater in granite. Therefore, the organic carbon dissolved from the bentonite will not cause a significant increase in the organic carbon content of deep groundwater in the repository environment. Overall, temperature effects on the sealing performance of buffer material in a waste repository is not important, if the maximum temperature is maintained below 100 deg. C

  17. Viability Assessment of a Repository at Yucca Mountain. Volume 3: Total System Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    This volume reports the development of TSPA for the VA. This first section defines the general process involved in developing any TSPA, it describes the overall TSPA process as implemented by programs in the US and elsewhere in the world, and discusses the acceptability of TSPA as a process or tool for analyzing a nuclear waste repository system. Section 2 discusses the more specific use of the TSPA process for the TSPA-VA for Yucca Mountain, including goals, approach, and methods. It also includes a very brief synopsis of TSPA-VA results. Section 3 briefly discusses each of the component models that comprise the TSPA-VA. Each TSPA component model represents a discrete set of processes. The TSPA-VA components are: unsaturated zone flow, thermal hydrology, near- field geochemical environment, waste package degradation, waste form alteration and mobilization, unsaturated zone transport, saturated zone flow and transport, and biosphere. For each of these components, this section introduces the conceptualization of each individual process, describes the data sources, and discusses model parameter development and computer methods used to simulate each component. Section 4 explains the mechanics of how the individual TSPA components were combined into a ''base case'' and then provides the ''expected value'' results of a deterministic base case analysis. Section 4 also contains a description of the probabilistic analyses and results that help determine the relative importance of the various TSPA components and the data used to describe the components. Section 5 addresses sensitivity studies run for each of the TSPA components to understand how uncertainty in various parameters within a component change the TSPA results. Section 6 presents the findings of the sensitivity studies run on the various components in Section 5, and prioritizes the findings of the entire set of uncertainty and sensitivity studies of the components relative

  18. Repository simulation model: Final report

    International Nuclear Information System (INIS)

    1988-03-01

    This report documents the application of computer simulation for the design analysis of the nuclear waste repository's waste handling and packaging operations. The Salt Repository Simulation Model was used to evaluate design alternatives during the conceptual design phase of the Salt Repository Project. Code development and verification was performed by the Office of Nuclear Waste Isolation (ONWL). The focus of this report is to relate the experience gained during the development and application of the Salt Repository Simulation Model to future repository design phases. Design of the repository's waste handling and packaging systems will require sophisticated analysis tools to evaluate complex operational and logistical design alternatives. Selection of these design alternatives in the Advanced Conceptual Design (ACD) and License Application Design (LAD) phases must be supported by analysis to demonstrate that the repository design will cost effectively meet DOE's mandated emplacement schedule and that uncertainties in the performance of the repository's systems have been objectively evaluated. Computer simulation of repository operations will provide future repository designers with data and insights that no other analytical form of analysis can provide. 6 refs., 10 figs

  19. Derivation of parameters necessary for the evaluation of performance of sites for deep geological repositories with particular reference to bedded salt, Livermore, California. Volume I. Main text

    International Nuclear Information System (INIS)

    Ashby, J.P.; Rawlings, G.E.; Soto, C.A.; Wood, D.F.; Chorley, D.W.

    1979-12-01

    A survey of parameters to be considered in the evaluation of sites for deep geologic nuclear waste repositories is presented. As yet, no comprehensive site selection procedure or performance evaluation approach has been adopted. A basis is provided for the development of parameters by discussing both site selection and performance evaluation. Three major groups of parameters are considered in this report: geologic, mining/rock mechanics, and hydrogeologic. For each type, the role of the parameter in the evaluation of repository sites is discussed. The derivation of the parameter by measurement, correlation, inference, or other method is discussed. Geologic parameters define the framework of the repository site and can be used in development of conceptual models and the prediction of long-term performance. Methods for deriving geological parameters include mapping, surveying, drilling, geophysical investigation, and historical and regional analysis. Rock mechanics/mining parameters are essential for the prediction of short-term performance and the development of initial conditions for modeling of long-term performance. Rock mechanics/mapping parameters can be derived by field or laboratory investigation, correlation, and theoretically or empirically based inference. Hydrogeologic parameters are the most important for assessment of long-term radionuclide confinement, since transport throughout the regional hydrogeologic system is the most likely mode of radionuclide escape from geologic repositories. Hydrogeologic parameters can be derived by hydrogeologic mapping and interpretation, hydrogeologic system modeling, field measurements, and lab tests. Procedures used in determination and statistical evaluation of geologic and rock mechanics parameters are discussed

  20. Derivation of parameters necessary for the evaluation of performance of sites for deep geological repositories with particular reference to bedded salt, Livermore, California. Volume I. Main text

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, J.P.; Rawlings, G.E.; Soto, C.A.; Wood, D.F.; Chorley, D.W.

    1979-12-01

    A survey of parameters to be considered in the evaluation of sites for deep geologic nuclear waste repositories is presented. As yet, no comprehensive site selection procedure or performance evaluation approach has been adopted. A basis is provided for the development of parameters by discussing both site selection and performance evaluation. Three major groups of parameters are considered in this report: geologic, mining/rock mechanics, and hydrogeologic. For each type, the role of the parameter in the evaluation of repository sites is discussed. The derivation of the parameter by measurement, correlation, inference, or other method is discussed. Geologic parameters define the framework of the repository site and can be used in development of conceptual models and the prediction of long-term performance. Methods for deriving geological parameters include mapping, surveying, drilling, geophysical investigation, and historical and regional analysis. Rock mechanics/mining parameters are essential for the prediction of short-term performance and the development of initial conditions for modeling of long-term performance. Rock mechanics/mapping parameters can be derived by field or laboratory investigation, correlation, and theoretically or empirically based inference. Hydrogeologic parameters are the most important for assessment of long-term radionuclide confinement, since transport throughout the regional hydrogeologic system is the most likely mode of radionuclide escape from geologic repositories. Hydrogeologic parameters can be derived by hydrogeologic mapping and interpretation, hydrogeologic system modeling, field measurements, and lab tests. Procedures used in determination and statistical evaluation of geologic and rock mechanics parameters are discussed.

  1. Groundwater age and lifetime expectancy modelling approach for site characterization and performance assessment of radwaste repository in clay formation

    International Nuclear Information System (INIS)

    Cornaton, F.; Perrochet, P.; Benabderrahmane, H.

    2010-01-01

    variables that are combined and used to assess the repository performance regarding its emplacement in the transposition zone. Age and lifetime expectancy distributions are solved considering advection and dispersion/diffusion processes according to the approach proposed by Cornaton and Perrochet (2006). Advective-dispersive age solutions are compared to available age dates of pore water within the two main calcareous aquifers (Dogger and Oxfordian) that embed the Callovo-Oxfordian host formation. Such a comparison is helpful for the consolidation of the flow calibration, the estimation of the transport porosity field (since porosity is age generator) and for analyzing the internal water mixing processes and hydraulic behavior of major faults. Lifetime expectancy solutions are used to predict the response at the biosphere resulting from contaminant mass input occurring at a series of hypothetical repository locations. Lifetime expectancy solutions combined with age solutions provide the distribution of total residence times within the domain (i.e the total time required to travel from recharge to discharge). The latter is used to map in the 3-D space the low- and high-speed flow zones at the local scale. Finally, the behavior of age solutions is investigated when the hydraulic regime is rendered transient in response to the climatic evolution during the past Million years and to the climatic projection for the coming Million years. Transient age solutions at actual time are useful to analyze the effect of the temporal flow regime variations on the measured age dates and on ages simulated under steady-flow conditions. (authors)

  2. Representation of two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    VAUGHN, PALMER; BEAN, J.E.; HELTON, JON CRAIG; LORD, MICHAEL E.; MACKINNON, ROBERT J.; SCHREIBER, JAMES D.

    2000-01-01

    The following topics related to the representation of two-phase (gas and brine) flow in the vicinity of the repository in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are discussed: (1) system of nonlinear partial differential equations used to model two-phase flow, (2) incorporation of repository shafts into model (3) creep closure of repository. (4) interbed fracturing, (5) gas generation (6) capillary action in waste, (7) borebole model (8) numerical solution and (9) gas and brine flow across specified boundaries. Two-phase flow calculations are a central part of the 1996 WIPP PA and supply results that are subsequently used in the calculation of releases to the surface at the time of a drilling intrusion (i.e., spallings, direct brine releases) and long-term releases due to radionuclide transport by flowing groundwater

  3. Uncertainty and sensitivity analysis in the 2008 performance assessment for the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Helton, Jon Craig; Sallaberry, Cedric M.; Hansen, Clifford W.

    2010-01-01

    Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. As part of this development, an extensive performance assessment (PA) for the YM repository was completed in 2008 (1) and supported a license application by the DOE to the U.S. Nuclear Regulatory Commission (NRC) for the construction of the YM repository (2). This presentation provides an overview of the conceptual and computational structure of the indicated PA (hereafter referred to as the 2008 YM PA) and the roles that uncertainty analysis and sensitivity analysis play in this structure.

  4. Development of design window evaluation and display system. 2. Confirmations of the basic performance of genetic algorithm

    International Nuclear Information System (INIS)

    Murakami, Satoshi; Muramatsu, Toshiharu

    2003-05-01

    A large- scale sodium-cooled fast breeder reactor in feasibility studies on commercialized fast reactors which has a tendency of consideration of through simplified and compacted system is being investigated, however special attention should be paid to thermohydraulic designs for a gas entrainment behavior from free surfaces, a flow-induced vibration of in-vessel components, a thermal shock for various structures due to high-speed coolant flows, nonsymmetrical coolant flows, etc. in the reactor vessel. As thus a lot of thermal-hydraulic issues relate to each other complicatedly on the reactor designs, multiple-criteria decision-making on the understanding of relationship among thermal-hydraulic issues is indispensable to design the reactor efficiently. Genetic Algorithm (GA), which is one of the methods for multiple-criteria decision-making, was applied to the typical simple objective optimization problems and then was confirmed its basic performance. From the analyses, the following results have been obtained. (1) In the unimodal optimization problem, it was confirmed that GA is capable of sufficient searching ability. (2) It was confirmed that GA can be also applied to the discrete optimization problems. (3) In the case of applying GA to the combinational optimization problem, the searching efficiency is improved better by increasing the number of experiment times than the maximum of generation. (4) In the case of applying Ga to the multimodal optimization problem, the searching ability is improved by using the two genetic operators (I.e., the mutation, and the elite strategy) at the same time. (author)

  5. On the Durability of Nuclear Waste Forms from the Perspective of Long-Term Geologic Repository Performance

    Directory of Open Access Journals (Sweden)

    Yifeng Wang

    2013-12-01

    Full Text Available High solid/water ratios and slow water percolation cause the water in a repository to quickly (on a repository time scale reach radionuclide solubility controlled by the equilibrium with alteration products; the total release of radionuclides then becomes insensitive to the dissolution rates of primary waste forms. It is therefore suggested that future waste form development be focused on conditioning waste forms or repository environments to minimize radionuclide solubility, rather than on marginally improving the durability of primary waste forms.

  6. Total system performance assessment - 1995: An evaluation of the potential Yucca Mountain repository

    Energy Technology Data Exchange (ETDEWEB)

    Atkins, J.E.; Lee, J.H.; Lingineni, S.; Mishra, S; McNeish, J.A.; Sassani, D.C.; Sevougian, S.D.

    1995-11-01

    The U.S. Department of Energy (DOE) is currently investigating the feasibility of permanently disposing the nation`s commercial high-level radioactive wastes (in the form of spent fuel from the over 100 electric power-generating nuclear reactors across the U.S.) and a portion of the defense high-level radioactive wastes (currently stored at federal facilities around the country) in the unsaturated tuffaceous rocks at Yucca Mountain, Nevada. Quantitative predictions based on the most current understanding of the processes and parameters potentially affecting the long-term behavior of the disposal system are used to assess the ability of the site and its associated engineered designs to meet regulatory objectives of the US NRC and the US EPA. The evaluation of the ability of the overall system to meet the performance objectives specified in the applicable regulatory standards has been termed total system performance assessment (TSPA). Total system performance assessments require the explicit quantification of the relevant processes and process interactions. In addition assessments are useful to help define the most significant processes, the information gaps and uncertainties and therefore the additional information required for more robust and defensible assessment of the overall performance. The aim of any total system performance assessment is to be as complete and reasonably conservative as possible and to assure that the descriptions of the predictive models and parameters are sufficient to ascertain their accuracy. Total system performance assessments evolve with time. Previous iterations of total system performance assessment of the Yucca Mountain site and associated engineered barriers have been conducted in 1991 and 1993.

  7. Total system performance assessment - 1995: An evaluation of the potential Yucca Mountain repository

    International Nuclear Information System (INIS)

    Atkins, J.E.; Lee, J.H.; Lingineni, S.; Mishra, S.; McNeish, J.A.; Sassani, D.C.; Sevougian, S.D.

    1995-11-01

    The U.S. Department of Energy (DOE) is currently investigating the feasibility of permanently disposing the nation's commercial high-level radioactive wastes (in the form of spent fuel from the over 100 electric power-generating nuclear reactors across the U.S.) and a portion of the defense high-level radioactive wastes (currently stored at federal facilities around the country) in the unsaturated tuffaceous rocks at Yucca Mountain, Nevada. Quantitative predictions based on the most current understanding of the processes and parameters potentially affecting the long-term behavior of the disposal system are used to assess the ability of the site and its associated engineered designs to meet regulatory objectives of the US NRC and the US EPA. The evaluation of the ability of the overall system to meet the performance objectives specified in the applicable regulatory standards has been termed total system performance assessment (TSPA). Total system performance assessments require the explicit quantification of the relevant processes and process interactions. In addition assessments are useful to help define the most significant processes, the information gaps and uncertainties and therefore the additional information required for more robust and defensible assessment of the overall performance. The aim of any total system performance assessment is to be as complete and reasonably conservative as possible and to assure that the descriptions of the predictive models and parameters are sufficient to ascertain their accuracy. Total system performance assessments evolve with time. Previous iterations of total system performance assessment of the Yucca Mountain site and associated engineered barriers have been conducted in 1991 and 1993

  8. Final draft position on geotechnical instrumentation in a salt repository environment: Requirements, performance, recommendations, and development needs

    International Nuclear Information System (INIS)

    1987-07-01

    This report presents the results of a study of the present status of geotechnical instrumentation with respect to potential use in an underground test facility at a candidate nuclear waste repository site in salt. Programmatic factors that have a general impact on the success of underground instrumentation are discussed. Performance requirements relating to accuracy, temperature range, longevity, and capability for automation are established on the basis of criteria proposed for other rock types, perceived needs of the Site Characterization Program, and the authors' experience and judgment. Test site conditions are discussed including underground logistics, corrosion, and other factors that affect instrument reliability. The status of existing instrumentation for measuring deformation, stress, temperature, fluid pressure, acoustic emission, and other less critical parameters is presented. For each instrument not presently capable of satisfying its associated performance requirements, specific development needs and possible approaches are identified, and necessary testing is describe to a conceptual level of detail. A brief discussion of instrument considerations relating to automatic data acquisition is also included. The position of instrument development as a key activity on the critical path under current schedules for the Site Characterization Program is discussed. Annotated references and reports on site visits and meetings used as the data base in evaluating present instrument status are appended to this report. 110 refs., 14 figs., 26 tabs

  9. Analysis and confirmation of synthetic anorexics in adulterated traditional Chinese medicines by high-performance capillary electrophoresis.

    Science.gov (United States)

    Ku, Y R; Chang, Y S; Wen, K C; Ho, L K

    1999-07-02

    Six synthetic anorexics, clobenzorex, diethylpropion, fenfluramine, methamphetamine, phenylpropanolamine and phentermine, which can be found as adulterants in traditional Chinese medicines were assayed simultaneously by high-performance capillary electrophoresis. The electrolyte was a buffer solution containing 120 mM phosphate buffer (NaH2PO4/H3PO4, pH 2.0) and 15% acetonitrile. Applied voltage was 16 kV and temperature was 30 degrees C. Fluoren-2,7-diammonium chloride was used as an internal standard and detector set at 200 nm. The recoveries of the synthetic anorexic adulterants in traditional Chinese medicinal formula using C8-SCX mixed solid-phase extraction were studied. Several traditional Chinese medicinal powders obtained from clinics were also studied by the above HPCE method and confirmed by GC-MS. Clobenzorex, diethylpropion and fenfluramine were found and determine in these samples.

  10. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 3; the groundwater pathway

    International Nuclear Information System (INIS)

    Baker, A.; Chambers, A.; Jackson, C.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  11. Total system performance assessment - 1995: An evaluation of the potential Yucca Mountain Repository

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The U.S. Department of Energy (DOE) is currently investigating the feasibility of permanently disposing the nation`s commercial high-level radioactive wastes (in the form of spent fuel from the over 100 electric power-generating nuclear reactors across the U.S.) and a portion of the defense high-level radioactive wastes (currently stored at federal facilities around the country) in the unsaturated tuffaceous rocks at Yucca Mountain, Nevada. Quantitative predictions based on the most current understanding of the processes and parameters potentially affecting the long-term behavior of the disposal system are used to assess the ability of the site and its associated engineered designs to meet regulatory objectives set forward by the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Environmental Protection Agency (EPA). The evaluation of the ability of the overall system to meet the performance objectives specified in the applicable regulatory standards has been termed total system performance assessment (TSPA). The aim of any total system performance assessment is to be as complete and reasonably conservative as possible and to assure that the descriptions of the predictive models and parameters are sufficient to ascertain their accuracy. Total system performance assessments evolve with time. As additional site and design information is generated, performance assessment analyses can be revised to become more representative of the expected conditions and remove some of the conservative assumptions necessitated by the incompleteness of site and design data. Previous iterations of total system performance assessment of the Yucca Mountain site and associated engineered barriers have been conducted in 1991 and 1993. These analyses have been documented in Barnard, Eslinger, Wilson and Andrews.

  12. Total system performance assessment - 1995: An evaluation of the potential Yucca Mountain Repository

    International Nuclear Information System (INIS)

    1995-11-01

    The U.S. Department of Energy (DOE) is currently investigating the feasibility of permanently disposing the nation's commercial high-level radioactive wastes (in the form of spent fuel from the over 100 electric power-generating nuclear reactors across the U.S.) and a portion of the defense high-level radioactive wastes (currently stored at federal facilities around the country) in the unsaturated tuffaceous rocks at Yucca Mountain, Nevada. Quantitative predictions based on the most current understanding of the processes and parameters potentially affecting the long-term behavior of the disposal system are used to assess the ability of the site and its associated engineered designs to meet regulatory objectives set forward by the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Environmental Protection Agency (EPA). The evaluation of the ability of the overall system to meet the performance objectives specified in the applicable regulatory standards has been termed total system performance assessment (TSPA). The aim of any total system performance assessment is to be as complete and reasonably conservative as possible and to assure that the descriptions of the predictive models and parameters are sufficient to ascertain their accuracy. Total system performance assessments evolve with time. As additional site and design information is generated, performance assessment analyses can be revised to become more representative of the expected conditions and remove some of the conservative assumptions necessitated by the incompleteness of site and design data. Previous iterations of total system performance assessment of the Yucca Mountain site and associated engineered barriers have been conducted in 1991 and 1993. These analyses have been documented in Barnard, Eslinger, Wilson and Andrews

  13. Estimation of waste package performance requirements for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Wood, B.J.

    1980-07-01

    A method of developing waste package performance requirements for specific nuclides is described, and based on federal regulations concerning permissible concentrations in solution at the point of discharge to the accessible environment, a simple and conservative transport model, and baseline and potential worst-case release scenarios

  14. Implementation of computer codes for performance assessment of the Republic repository of LLW/ILW Mochovce

    International Nuclear Information System (INIS)

    Hanusik, V.; Kopcani, I.; Gedeon, M.

    2000-01-01

    This paper describes selection and adaptation of computer codes required to assess the effects of radionuclide release from Mochovce Radioactive Waste Disposal Facility. The paper also demonstrates how these codes can be integrated into performance assessment methodology. The considered codes include DUST-MS for source term release, MODFLOW for ground-water flow and BS for transport through biosphere and dose assessment. (author)

  15. Applicability of thermodynamic database of radioactive elements developed for the Japanese performance assessment of HLW repository

    International Nuclear Information System (INIS)

    Yui, Mikazu; Shibata, Masahiro; Rai, Dhanpat; Ochs, Michael

    2003-01-01

    In 1999 Japan Nuclear Cycle Development Institute (JNC) published a second progress report (also known as H12 report) on high-level radioactive waste (HLW) disposal in Japan (JNC 1999). This report helped to develop confidence in the selected HLW disposal system and to establish the implementation body in 2000 for the disposal of HLW. JNC developed an in-house thermodynamic database for radioactive elements for performance analysis of the engineered barrier system (EBS) and the geosphere for H12 report. This paper briefly presents the status of the JNC's thermodynamic database and its applicability to perform realistic analyses of the solubilities of radioactive elements, evolution of solubility-limiting solid phases, predictions of the redox state of Pu in the neutral pH range under reducing conditions, and to estimate solubilities of radioactive elements in cementitious conditions. (author)

  16. Obtaining reasonable assurance on geochemical aspects of performance assessment of deep geologic repositories

    International Nuclear Information System (INIS)

    Van Luik, A.E.; Serne, R.J.

    1986-01-01

    Providing reasonable assurance that a deep geologic disposal system will perform as required by regulation involves, in part, the building of confidence by providing a sound scientific basis for the site characterization, engineered system design, and system performance modeling efforts. Geochemistry plays a role in each of these activities. Site characterization must result in a description of the in situ geochemical environment that will support the design of the engineered system and the modeling of the transport of specific radionuclides to the accessible environment. Judging the adequacy of this site characterization effort is a major aspect of providing reasonable assurance. Within site characterization, there are a number of geochemical issues that need to be addressed such as the usefulness of natural analog studies, and assessing the very long-term stability of the site geochemistry, given expected temperature and radiation conditions

  17. Validation of transport models for use in repository performance assessments: a view illustrated for INTRAVAL test case 1b

    International Nuclear Information System (INIS)

    Jackson, C.P.; Lever, D.A.; Sumner, P.J.

    1991-03-01

    We present our views on validation. We consider that validation is slightly different for general models and specific models. We stress the importance of presenting for review the case for (or against) a model. We outline a formal framework for validation, which helps to ensure that all the issues are addressed. Our framework includes calibration, testing predictions, comparison with alternative models, which we consider particularly important, analysis of discrepancies, presentation, consideration of implications and suggested improved experiments. We illustrate the approach by application to an INTRAVAL test case based on laboratory experiments. Three models were considered: a simple model that included the effects of advection, dispersion and equilibrium sorption, a model that also included the effects of rock-matrix diffusion, and a model with kinetic sorption. We show that the model with rock-matrix diffusion is the only one to provide a good description of the data. We stress the implications of extrapolating to larger length and time scales for repository performance assessments. (author)

  18. SEALEX in-situ experiments-performance tests of repository seals: experimental observations and modelling

    Directory of Open Access Journals (Sweden)

    Mokni Nadia

    2016-01-01

    Full Text Available The paper describes observations and numerical analysis of SEALEX performance tests installed in Tournemire Underground Research Laboratory (URL. One of the objectives of the large scale in-situ tests is to investigate the impact of technological gaps on the long term performance of bentonite based seals. The swelling cores consist of pre-compacted blocks of a natural sodic Wyoming bentonite (MX80 type mixed with quartz sand in a ratio of 70/30 (in dry mass with different geometries (monolithic disks or four jointed disks. Several technological gaps exist within the in situ tests: Gaps between the blocks and annular gap with variable width between the bentonite-based core and the host rock. All the tests are extensively instrumented for monitoring the main Hydro-Mechanical (HM variables. Comparison of the experimental results showed that the presence of technological gaps constituted new hydration sources (annular gaps and flow paths (gaps between the blocks that changed the saturation kinetics. A coupled HM formulation that incorporates the relevant processes involved in the problem under consideration has been adopted to analyse the effect of the annular technological gap on dry density homogenization of the bentonite based core as hydration progresses. Technological gaps were demonstrated to have an impact on dry density distribution.

  19. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    International Nuclear Information System (INIS)

    Randle, D.C.

    2000-01-01

    The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

  20. NRC iterative performance assessment Phase 2. Development of capabilities for review of a performance assessment for a high-level waste repository

    International Nuclear Information System (INIS)

    Wescott, R.G.; Lee, M.P.; Eisenberg, N.A.; Baca, R.G.

    1995-10-01

    In order to better review a potential license application to construct and operate a geologic repository for spent nuclear fuel and high-level radioactive waste (HLW), the Nuclear Regulatory Commission staff (and its contractor) has expanded and improved its capability to conduct performance assessments. This report documents the demonstration of the second phase of this capability. The demonstration made use of the scenario selection procedure developed by Sandia National Laboratories to provide a set of scenarios, with corresponding probabilities, for use in the consequence analysis of a potential HLW disposal site in unsaturated tuff. Models of release of radionuclides from the waste form and transport in ground water, air and by direct pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year period. The input values of parameters necessary for the consequence models were sampled numerous times using Latin Hypercube Sampling from assumed probability distributions. The results from the consequence models were then used to generate Complementary Cumulative Distribution Functions (CCDFs) for either release to the accessible environment or effective dose equivalents to a target population. CCDFs were calculated for probabilistically significant combinations (scenarios) of four disruptive events; drilling, pluvial climate, seismicity and magmatism. Sensitivity and uncertainty analyses of the calculated releases and effective dose equivalents were also used to determine the importance of the parameters. Because of the preliminary nature of the analysis and the lack of an adequate data base, the results and conclusions presented in this report should be carefully interpreted. They should not be misconstrued to represent the actual performance of the proposed Yucca Mountain repository nor serve as an endorsement of the methods used

  1. Repository site characterization

    International Nuclear Information System (INIS)

    Voss, J.W.; Pentz, D.L.

    1987-01-01

    The characterization of candidate repository sites has a number of programmatic objectives. Principal among these is the acquisition of data: a) to determine the suitability of a site relative to the DOE repository siting guidelines, b) to support model development and calculations to determine the suitability of a site relative to the post closure criteria of the NRC and EPA, c) to support the design of a disposal system, including the waste package and the engineered barrier system, as well as the shafts and underground openings of the repository. In meeting the gaols of site characterization, the authors have an obligation to conduct their investigations within an appropriate budget and schedule. This mandates that a well-constructed and systematic plan for field investigations be developed. Such a plan must fully account for the mechanisms which will control the radiologic performance in the repository. The plan must also flexibly and dynamically respond to the results of each step of field investigation, responding to the spatial variability of earth as well as to enhanced understandings of the performance of the disposal system. Such a plan must ensure that sufficient data are available to support the necessary probabilistic calculations of performance. This paper explores the planning for field data acquisition with specific reference to requirements for demonstrations of the acceptable performance for disposal systems

  2. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 1: hydrogeological model development - conceptual basis and data

    International Nuclear Information System (INIS)

    Degnan, P.; Littleboy, A.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  3. The role of the disturbed rock zone in radioactive waste repository safety and performance assessment. A topical discussion and international overview

    International Nuclear Information System (INIS)

    Winberg, A.

    1991-06-01

    A discussion was presented of the role and relative importance of the disturbed rock zone (DRZ) around the underground openings of a repository for nuclear waste in crystalline rock. The term disturbed rock zone was defined and possible criteria to be sued to distinguish if from undisturbed rock was suggested. The processes decisive for the hydraulic characteristics of the DRZ were discussed. With regard to the integral hydraulic characteristics of the DRZ, the effects of the excavation methodology, stress redistribution, thermal changes, chemical changes and backfill were discussed. A review of in-situ observations of the DRZ was provided. Model analysis where the DRZ has been explicitly or implicitly represented, either from a phenomenological and performance assessment aspect were reviewed. The implications of the disturbed rock zone for the safe performance of a nuclear waste repository were discussed. Conceptual models for the geometry of the DRZ and hydraulic conductivity distribution in the DRZ were suggested. (au) (82 refs.)

  4. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 2; hydrogeological conceptual model development - effective parameters and calibration appendix

    International Nuclear Information System (INIS)

    Jackson, C.; Watson, S.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  5. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 2; hydrogeological conceptual model development - effective parameters and calibration

    International Nuclear Information System (INIS)

    Jackson, C.; Watson, S.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  6. Technology overview of mined repositories

    International Nuclear Information System (INIS)

    Gimera, R.; Thirumalai, K.

    1982-01-01

    Mined repositories present an environmentally viable option for permanent disposal of nuclear waste. This paper reviews the state-of-the-art mining technologies and identifies technological issues and developments necessary to mine a repository in basalt. The thermal loading, isolation, and retrieval requirements of a repository present unique technological challenges unknown to conventional mining practice. The technology issues and developments required in the areas of excavation, roof and ground support, equipment development, instrumentation development, and sealing are presented. Performance assessment methods must be developed to evaluate the adequacies of technologies developed to design, construct, operate, and decommission a repository. A stepwise test-and-development approach is used in the Basalt Waste Isolation Project to develop cost-effective technologies for a repository

  7. Properties of altered soils by alkaline solution: contribution in the performance evaluation of repositories; Propriedades de solos alterados por solucao alcalina: contribuicao na avaliacao de desempenho de repositorios

    Energy Technology Data Exchange (ETDEWEB)

    Calabria, Jaqueline Alves de Almeida

    2015-07-01

    The radioactive wastes from nuclear technology applications must be properly disposed in a repository, during the necessary time to ensure the human and the environment protection. The surface systems are largely considered for disposal of low and intermediate level radioactive waste, but generally require the use of engineering barriers to control the radionuclides release. An important engineering barrier is the backfill which is situated between the package and structural material, and has the functions of reducing the water infiltration and to promote the retardation of the radionuclide migration, among others. Therefore, the material to be used as backfill such as clays, cement, soils, rocks, must has good sorption, permeability and mechanical properties. The selection of the material will depend also largely on the material availability and installation design. The concrete is also used in the construction of repository, and its interaction with water induces its degradation, resulting in a high pH solution. This solution interacts with the backfilling materials promoting mineralogical alterations that results in significant changes in their key properties and performance as safety component of the repository. In this work, five Brazilian soils of Minas Gerais state, selected according to their generic characteristics along with information from Sistema Brasileiro de Classificacao de Solos (SiBCS) were investigated concerning their potential use as backfilling material in a superficial repository by the determination of retention capacity for cesium and iodine. Sorption-related parameters, used in the performance assessment of the soils, were obtained from experimental data fitting to different sorption isotherms models. The soil that showed the best sorption of Cs, was a clay soil that presented distribution coefficient (K{sub d}) of 90.5 mL.g{sup -1} and maximum sorption capacity (Q{sub max}) of 18.372 mg.g{sup -1}. Regarding the iodine, the sorption was

  8. Safety analysis methodologies for radioactive waste repositories in shallow ground

    International Nuclear Information System (INIS)

    1984-01-01

    The report is part of the IAEA Safety Series and is addressed to authorities and specialists responsible for or involved in planning, performing and/or reviewing safety assessments of shallow ground radioactive waste repositories. It discusses approaches that are applicable for safety analysis of a shallow ground repository. The methodologies, analysis techniques and models described are pertinent to the task of predicting the long-term performance of a shallow ground disposal system. They may be used during the processes of selection, confirmation and licensing of new sites and disposal systems or to evaluate the long-term consequences in the post-sealing phase of existing operating or inactive sites. The analysis may point out need for remedial action, or provide information to be used in deciding on the duration of surveillance. Safety analysis both general in nature and specific to a certain repository, site or design concept, are discussed, with emphasis on deterministic and probabilistic studies

  9. Spent fuel and high level waste: Chemical durability and performance under simulated repository conditions. Results of a coordinated research project 1998-2004

    International Nuclear Information System (INIS)

    2007-10-01

    This publication contains the results of an IAEA Coordinated Research Project (CRP). It provides a basis for understanding the potential interactions of waste form and repository environment, which is necessary for the development of the design and safety case for deep disposal. Types of high level waste matrices investigated include spent fuel, glasses and ceramics. Of particular interest are the experimental results pertaining to ceramic forms such as SYNROC. This publication also outlines important areas for future work, namely, standardized, collaborative experimental protocols for package-release studies, structured development and calibration of predictive models linking the performance of packaged waste and the repository environment, and studies of the long term behaviour of the wastes, including active waste samples

  10. Learning Object Repositories

    Science.gov (United States)

    Lehman, Rosemary

    2007-01-01

    This chapter looks at the development and nature of learning objects, meta-tagging standards and taxonomies, learning object repositories, learning object repository characteristics, and types of learning object repositories, with type examples. (Contains 1 table.)

  11. Retrievability as proposed in the US repository concept

    International Nuclear Information System (INIS)

    Harrington, P.G.

    2000-01-01

    The Nuclear Waste Policy Act states that any repository shall be designed and constructed to permit retrieval. Reasons for retrieval include public health and safety, environmental concerns, and recovery of economically valuable contents of spent nuclear fuel. The Nuclear Regulatory Commission requires that waste must be retrievable at any time up to 50 years after start of emplacement. The US Department of Energy intends to maintain a retrieval capability throughout the preclosure period. Possible preclosure periods range from a minimum of 50 years to as much as 300 years. Repository closure includes sealing all accessible portions of the repository, including ventilation shafts, access ramps and boreholes. Drip shields will be installed over the waste packages. Access to the repository after closure is not intended. The proposed repository includes horizontal emplacement drifts located in the unsaturated zone. The emplacement drift centerline spacing is 81 meters to provide a subboiling region between drifts for water drainage. A drip shield covers the waste packages. All emplacement drifts remain open until closure of the repository, providing performance benefits such as removing heat and moisture during the preclosure period and lowering postclosure temperatures. This does not impede retrieval, permitting a reversal of the emplacement process to accomplish retrieval under normal conditions. The preclosure period is therefore not to enhance retrievability, but does improve performance, and the resultant extension of the retrievability capability is a secondary effect. Information must be provided from the performance confirmation program to support a regulatory decision to close. Closure would isolate the repository from the accessible environment, preclude preferential flowpaths for water into the mountain, and minimize the possibility of inadvertent intrusion. (author)

  12. Zedex - an in-situ study of the importance of the excavation disturbed zone to repository performance

    International Nuclear Information System (INIS)

    Olsson, O.; Slimane K.B.; Davies, N.

    1995-01-01

    The excavation of shafts and tunnels in a waste repository will cause a disturbance to the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. The properties and extent of the disturbed zone must be considered in the design of a repository and in the assessment of its long-term safety. In addition, the data collected in drifts, which will be used for detailed characterization of the repository, will be affected by excavation effects. ANDRA, UK Nirex, and SKB have jointly set up the ZEDEX Project at the Aespoe Hard Rock Laboratory, Sweden, in order to improve understanding of the properties and extent the Excavation Disturbed Zone (EDZ). The main objective is to study the mechanical behavior of the EDZ with respect to its origin, character, magnitude of property change, extent, and its dependence of excavation method. The project will also provide a test of equipment and methodology for quantifying the EDZ. The ZEDEX Project includes tests of open-quote normal close-quote excavation by drill and blast, a smooth blasting procedure based on low shock explosives, and excavation by tunnel boring. The ZEDEX Project is still in progress and results have not been fully analyzed. The preliminary analysis of the results indicates that the measurable changes in properties induced by tunnel excavation are comparatively small

  13. Why is variability important for performance assessment and what are its consequences for site characterisation and repository design?

    International Nuclear Information System (INIS)

    Dverstorp, B.; Smith, P.A.; Zuidema, P.

    1998-01-01

    The importance of spatial variability is discussed in terms of its consequences for site characterisation and for repository design and safety. Variability is described in terms of various scales of discrete structural features and a pragmatic classification is proposed according to whether the features are: feasibility-determining (i.e. features within which repository construction and operation is not practical and which preclude long-term safety); layout-determining (i.e. features which, if avoided, would enhance long-term safety); safety-determining features (i.e. features which cannot be shown to be avoidable and which strongly influence the calculated long-term safety of the repository system). The significance with respect to the geosphere-transport barrier of small-scale pore structure within the various classes of feature is also discussed. The practical problems of characterising variability and modelling its effects on radionuclide transport are described. Key factors affecting groundwater flow and radionuclide transport are identified, models that incorporate spatial variability are described and the estimation of appropriate parameters for these models is discussed. (author)

  14. Cementitious Near-Field Sorption Data Base for Performance Assessment of an ILW Repository in Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E.; Van Loon, L. R

    2003-08-01

    The present report describes a cement sorption database (SDB) for the safety-relevant radionuclides to be disposed of in the planned Swiss repository for long-lived intermediate-level radioactive wastes (ILW). This report is an update on earlier SDBs, which were compiled for the cementitious near field of a repository for low- and intermediate-level radioactive wastes (L/ILW) by BRADBURY + SAROTT (1995) and BRADBURY + VAN LOON (1998). The radionuclide inventories are determined by the waste streams to be disposed of in the ILW repository. A list of the safety-relevant radionuclides was provided based on the currently available information on ILW inventories. The compositions of the cement porewaters in the near fields of the L/ILW and ILW repositories, which had been calculated using well-established codes for modelling cement degradation, were compared to identify any differences in the near-field conditions and to assess their influence on radionuclide sorption. Sorption values were selected based on the previously reported SDBs for the near field of the L/ILW repository. Sorption values were revised if new information and/or data were available which allowed changes to or re-appraisals of the data to be made. The sorption values recommended in this report were either selected on the basis of data from in-house experimental studies or from literature data. For some key radioelements, i.e., Cs(l), Sr(II), Ni(II), Eu(lll), Th(IV) and Sn(IV), new data were available from in-house measurements. These elements had been selected for experimental studies due to their relevance to safety assessment and/or their importance as appropriate chemical analogues. Degradation products of bitumen and cellulose, concrete admixtures and cement-derived near-field colloids were taken into account as the main potential perturbations, which could reduce radionuclide sorption in the near field. Possible impacts of the perturbing factors on radionuclide mobility were considered and

  15. Probabilistic modelling of gas generation in nuclear waste repositories under consideration of new studies performed at the WIPP

    International Nuclear Information System (INIS)

    Niemeyer, M.; Wilhelm, S.; Poppei, J.

    2012-01-01

    Document available in extended abstract form only. The inventory of a nuclear waste repository includes significant amounts of metal and organic matter. Under the prevailing conditions in a repository in a salt formation in contact with water, these materials tend to react and transform under significant gas production. This increases the pressure and potentially leads to an enhanced transport of radio nuclides. Therefore, these phenomena need to be understood and characterized in detail for the assessment of the safety of the repository A modelling code, GASGEN, developed by AF-Consult Switzerland Ltd to predict the evolution of gas production by microbial processes and anaerobic corrosion of metal, was applied at two locations of repositories in salt rock in Germany. Therein, the microbial decomposition of organic waste components is modelled by the sub-processes of denitrification, reduction of sulphates, fermentation and methano-genesis. The models differentiate between highly degradable cellulose and materials of lesser degradability, such as polymers. Gas production through anaerobic corrosion of metal is mainly due to the iron content of the waste. In addition, the precipitation of carbonate from alkaline materials in the inventory (e.g. cement) is considered. The inventories of contained waste, which determine the amount of gas that can be produced, are subject to uncertainties. The rates of the various reactions also depend on numerous factors and are therefore variable. In order to cover this variability, gas production is modelled probabilistically. In this way the behaviour of the gas generation can be estimated together with its bandwidth Figure 1. In addition to the produced amounts of gas, the model calculations also consider the potential of acidification of the fluid enclosed in the repository chambers and the effect of a changing pH-level on the rate of corrosion. Based on results, the effect of a pH-dependent corrosion rate is illustrated and the

  16. Expected dose for the early failure scenario classes in the 2008 performance assessment for the proposed high-level radioactive waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Helton, J.C.; Hansen, C.W.; Sallaberry, C.J.

    2014-01-01

    Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. In support of this development and an associated license application to the U.S. Nuclear Regulatory Commission (NRC), the DOE completed an extensive performance assessment (PA) for the proposed YM repository in 2008. This presentation describes the determination of expected dose to the reasonably maximally exposed individual (RMEI) specified in the NRC regulations for the YM repository for the early waste package (WP) failure scenario class and the early drip shield (DS) failure scenario class in the 2008 YM PA. The following topics are addressed: (i) properties of the early failure scenario classes and the determination of dose and expected dose the RMEI, (ii) expected dose and uncertainty in expected dose to the RMEI from the early WP failure scenario class, (iii) expected dose and uncertainty in expected dose to the RMEI from the early DS failure scenario class, (iv) expected dose and uncertainty in expected dose to the RMEI from the combined early WP and early DS failure scenario class with and without the inclusion of failures resulting from nominal processes, and (v) uncertainty in the occurrence of early failure scenario classes. The present article is part of a special issue of Reliability Engineering and System Safety devoted to the 2008 YM PA; additional articles in the issue describe other aspects of the 2008 YM PA. - Highlights: • Extensive work has been carried out by the U.S. DOE in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. • Properties of the early failure scenario classes (i.e. early waste package failure and early drip shield failure) in the 2008 YM performance assessment are described. • Determination of dose, expected dose and expected (mean

  17. Tools for Managing Repository Objects

    OpenAIRE

    Banker, Rajiv D.; Isakowitz, Tomas; Kauffman, Robert J.; Kumar, Rachna; Zweig, Dani

    1993-01-01

    working Paper Series: STERN IS-93-46 The past few years have seen the introduction of repository-based computer aided software engineering (CASE) tools which may finally enable us to develop software which is reliable and affordable. With the new tools come new challenges for management: Repository-based CASE changes software development to such an extent that traditional approaches to estimation, performance, and productivity assessment may no longer suffice - if they ever...

  18. Characterization, propagation and analysis of aleatory and epistemic uncertainty in the 2008 performance assessment for the proposed repository for radioactive waste at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Helton, Jon Craig; Sallaberry, Cedric M.; Hansen, Clifford W.

    2010-01-01

    The 2008 performance assessment (PA) for the proposed repository for high-level radioactive waste at Yucca Mountain (YM), Nevada, illustrates the conceptual structure of risk assessments for complex systems. The 2008 YM PA is based on the following three conceptual entities: a probability space that characterizes aleatory uncertainty; a function that predicts consequences for individual elements of the sample space for aleatory uncertainty; and a probability space that characterizes epistemic uncertainty. These entities and their use in the characterization, propagation and analysis of aleatory and epistemic uncertainty are described and illustrated with results from the 2008 YM PA.

  19. Salt Repository Project shaft design guide: Revision 0

    International Nuclear Information System (INIS)

    1987-12-01

    The Salt Repository Project (SRP) Shaft Design Guide (SDG) and the accompanying SRP Input to Seismic Design define the basic approach for developing appropriate shaft designs for a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. The SDG is based on current mining industry standards and practices enhanced to meet the special needs of an underground nuclear waste repository. It provides a common approach for design of both the exploratory and repository shafts. The SDG defines shaft lining and material concepts and presents methods for calculating the loads and displacements that will be imposed on lining structures. It also presents the methodology and formulae for sizing lining components. The SDG directs the shaft designer to sources of geoscience and seismic design data for the Deaf Smith County, Texas repository site. In addition, the SDG describes methods for confirming shaft lining design by means of computer analysis, and it discusses performance monitoring needs that must be considered in the design. 113 refs., 18 figs., 14 tabs

  20. To Confirm or to Conform? Performance Goals as a Regulator of Conflict with More-Competent Others

    Science.gov (United States)

    Sommet, Nicolas; Darnon, Céline; Butera, Fabrizio

    2015-01-01

    Despite the fact that most competence-relevant settings are "socially" relevant settings, the interpersonal effects of achievement goals have been understudied. This is all the more surprising in the case of performance goals, for which self-competence is assessed using an other-referenced standard. In the present research, performance…

  1. Staged Repository Development Programmes

    International Nuclear Information System (INIS)

    Isaacs, T

    2003-01-01

    Programs to manage and ultimately dispose of high-level radioactive wastes are unique from scientific and technological as well as socio-political aspects. From a scientific and technological perspective, high-level radioactive wastes remain potentially hazardous for geological time periods-many millennia-and scientific and technological programs must be put in place that result in a system that provides high confidence that the wastes will be isolated from the accessible environment for these many thousands of years. Of course, ''proof'' in the classical sense is not possible at the outset, since the performance of the system can only be known with assurance, if ever, after the waste has been emplaced for those geological time periods. Adding to this challenge, many uncertainties exist in both the natural and engineered systems that are intended to isolate the wastes, and some of the uncertainties will remain regardless of the time and expense in attempting to characterize the system and assess its performance. What was perhaps underappreciated in the early days of waste management and repository program development were the unique and intense reactions that the institutional, political, and public bodies would have to repository program development, particularly in programs attempting to identify and then select sites for characterization, design, licensing, and ultimate development. Reactions in most nations were strong, focused, unrelenting, and often successful in hindering, derailing, and even stopping national repository programs. The reasons for such reactions and the measures to successfully respond to them are still evolving and continue to be the focus of many national program and political leaders. Adaptive Staging suggests an approach to repository program development that reflects the unique challenges associated with the disposal of high-level radioactive waste. The step-wise, incremental, learn-as-you-go approach is intended to maximize the

  2. Performance on Functional Strength Measurement and Muscle Power Sprint Test confirm poor anaerobic capacity in children with Developmental Coordination Disorder.

    Science.gov (United States)

    Aertssen, Wendy F M; Ferguson, Gillian D; Smits-Engelsman, Bouwien C M

    2016-12-01

    There is little and conflicting information about anaerobic performance and functional strength in children with Developmental Coordination Disorder (DCD). To investigate anaerobic capacity and functional strength in children with a clinical diagnosis of DCD (clin-DCD) and if differences were larger in older (age 7-10 years) compared to younger children (age 4-6 years). Furthermore to determine the percentage of children with clin-DCD that scored Strength Measurement. A clin-DCD group (36 boys, 11 girls, mean age: 7y 1mo, SD=2y 1mo) and a typically developing group (TD) (57 boys, 53 girls, mean age: 7y 5mo, SD=1y 10mo) were compared on Muscle Power Sprint Test (MPST) and Functional Strength Measurement (FSM). Children with clin-DCD performed poorer on the MPST and FSM, especially on the muscle endurance items of the FSM. The differences were larger in the older children compared to the younger on the cluster muscle endurance and the FSM total score. Over 50% of clin-DCD group scored tested on items requiring fast repetitive movements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Food safety evaluation: Detection and confirmation of chloramphenicol in milk by high performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Nicolich, Rebecca S.; Werneck-Barroso, Eduardo; Marques, Marlice A. Sipoli

    2006-01-01

    A simple and rapid procedure for extraction of chloramphenicol (CAP) in milk and analysis by high-performance liquid chromatography coupled with quadrupole mass spectrometry in tandem was developed. The method consisted of one step of liquid-liquid extraction using ethyl acetate and acidified water (10 mmol L -1 formic acid) and HPLC-MS/MS detection. CAP-D5 was used as internal standard. The method was validated according to Commission Decision 2002/657/EC. The calibration curves were linear, with typical r 2 values higher than 0.98. Absolute recovery of CAP from milk proved to be more than 95%, however CAP-D5 absolute recovery was 75%. The method was accurate and reproducible, being successfully applied to the monitoring of CAP in milk samples obtained from the Brazilian market. Decision limit (CCα) was 0.05 ng mL -1 and detection capability (CCβ) was 0.09 ng mL -1

  4. The Use of Numerical Models in Support of Site Characterization and Performance Assessment Studies of Geological Repositories. Results of an IAEA Coordinated Research Project 2005-2010

    International Nuclear Information System (INIS)

    2013-10-01

    The siting, development and operation of waste disposal facilities, and the related safety issues, have been described in many IAEA publications. The safe management and disposal of radioactive waste from the nuclear fuel cycle remains a necessary condition for future development of nuclear energy. In particular, the disposal of high level waste and spent nuclear fuel in geological repositories, despite having been studied worldwide over the past several decades, still requires full scale demonstration through safe implementation, as planned at the national level in Finland and Sweden by 2020 and 2023, respectively, and in France by 2025. Safety assessment techniques are currently applicable to potential facility location and development through a quite large range of approaches and methodologies. By implementing research activities through coordinated research projects (CRPs), the IAEA enables research institutes in both developing and developed Member States to collaborate on research topics of common interest. In response to requests by several Member States in different networks and platforms dealing with waste disposal, in 2005 a CRP on The Use of Numerical Models in Support of Site Characterization and Performance Assessment Studies of Geological Repositories was proposed and developed to transfer modelling expertise and numerical simulation technology to countries needing them for their national nuclear waste management programmes. All Member States involved in this CRP have acquired the scientific basis for, and expertise in, the site characterization process, including test design, data analysis, model calibration, model validation, predictive modelling, sensitivity analysis and uncertainty propagation analysis. This expertise is documented in this publication, in which numerical modelling is used to address the pertinent issue of site characterization and its impact on safety, using data and information from a potential repository site

  5. Electrochemical and micro-gravimetric corrosion studies on spent fuel provide relevant source term data for a repository performance assessment

    International Nuclear Information System (INIS)

    Wegen, Detlef H.; Bottomley, Paul D. W.; Glatz, Jean-Paul

    2004-01-01

    Various electrochemical methods (corrosion potential monitoring, AC impedance analysis and electrochemical noise monitoring) were used in the investigation of UO 2 samples: natural and doped with two different levels of 238 Pu (0.1 and 10 wt%) simulating the increasing α-intensities seen with time in the repository. The results were compared and were able to show the intense, but also the very local nature of the radiolysis and to demonstrate that corrosion rates were proportional to α-radiolysis and hence the 238 Pu content; the corrosion rates were in accordance with earlier work at ITU. By contrast it was seen that the redox potentials only gave information as to the bulk solution that did not reflect the true conditions at the electrode interface that were driving the corrosion processes of UO 2 dissolution in groundwaters. The study shows how electrochemical techniques can provide vital information on the corrosion mechanism at the UO 2 /solution interface

  6. Fundamental criteria for the design of high-performance Josephson nondestructive readout random access memory cells and experimental confirmation

    International Nuclear Information System (INIS)

    Henkels, W.H.

    1979-01-01

    Fundamental design criteria for Josephson nondestructive readout random access memory (NDRO RAM) cells are presented, within the context of an LSI array environment. Emphasis is placed upon principles which are relevant to high performance. The criteria are elucidated via a specific design which is simulated and then experimentally evaluated in a technology with a smallest critical dimension of 5 μm. The specific cell differs from previously tested Josephson NDRO cells in several respects; namely, the cell stores only approx.8Phi 0 , employs interferometer gates and an external damping resistor, allows switching into device resonances, and eliminates the need for a special initialization cycle. The cell-selection scheme, employing triple coincidence, results in larger operating margins and smaller operating currents than have previously been achieved. The large operating margins and all basic cell design criteria were experimentally verified. The experimental interferometer gate characteristics were analyzed in detail and found to be describable by simple models. In addition, it was discovered that single flux quantum transitions in the interferometer gates could be exploited beneficially in order to enhance the insensitivity of operating margins to fabrication tolerances

  7. Spent fuel and high level waste: Chemical durability and performance under simulated repository conditions. Results of a coordinated research project 1998-2004. Part 1: Contributions by participants in the co-ordinated research project on chemical durability and performance assessment under simulated repository conditions

    International Nuclear Information System (INIS)

    2007-07-01

    This publication contains the results of an IAEA Coordinated Research Project (CRP). It provides a basis for understanding the potential interactions of waste form and repository environment, which is necessary for the development of the design and safety case for deep disposal. Types of high level waste matrices investigated include spent fuel, glasses and ceramics. Of particular interest are the experimental results pertaining to ceramic forms such as SYNROC. This publication also outlines important areas for future work, namely, standardized, collaborative experimental protocols for package-release studies, structured development and calibration of predictive models linking the performance of packaged waste and the repository environment, and studies of the long term behaviour of the wastes, including active waste samples. It comprises 15 contributions of the participants on the Coordinated Research Project which are indexed individually.

  8. Spent fuel and high level waste: Chemical durability and performance under simulated repository conditions. Results of a coordinated research project 1998-2004. Part 2: Results of a previously unpublished CRP: Performance of high level waste forms and packages under repository conditions. Results of a co-ordinated research project 1991-1998

    International Nuclear Information System (INIS)

    2007-07-01

    The objective of the CRP (Coordinated Research Projekt) on the 'Performance of High Level Waste Forms and Packages under Repository Conditions' was to contribute to the development and implementation of proper and sound technologies for HLW and spent fuel management. Special emphasis was given to the identification of various waste form properties and the study of their long term durability in simulated repository conditions. Another objective was to promote the co-operation and exchange of information between Member States on experimental concerning behaviour of the waste form. The CRP was composed of research contracts and agreements with Argentina, Australia, Belgium, Canada, China, Czech Republic, Finland, France, Germany, India, Japan, Russia, and the United States of America. The publication includes 14 individual contributions of the participants to the CRP, which are indexed separately.

  9. Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage (3). Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

    International Nuclear Information System (INIS)

    Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Oda, Chie; Ishidera, Takamitsu; Suyama, Tadahiro; Hatanaka, Koichiro; Kamei, Gento; Yoshikawa, Hideki; Senba, Takeshi; Seo, Toshihiro; Kurosawa, Susumu; Goto, Junichi; Shibutani, Sanae; Goto, Takahiro; Kubota, Shigeru; Inagaki, Manabu; Moriya, Toshifumi; Suzuki, Satoru; Ishida, Keisuke; Nishio, Hikaru; Makiuchi, Akie; Fujihara, Hiroshi

    2015-03-01

    JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on host rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for “defining conditions” has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed through its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed through its application to key radionuclides. (author)

  10. Confirmation tests of construction method and initial performance quality for low permeable engineered barrier in side part of radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Yamada, Atsuo; Chijimatsu, Masakazu; Akiyama, Yoshihiro; Komine, Hideo; Iizuka, Atsushi

    2016-01-01

    As for the low permeable layer, important functions are expected as an engineered barrier of radioactive waste disposal for low-level waste with comparatively high radiation levels. On examining the construction methods of this low permeable layer, it is important to confirm the possibility of the construction in the conditions similar to the actual constructed conditions with a true scale size. Therefore, the construction examination for the side part of the low permeable layer by bentonite and the performance check test of the low permeable layer were carried out. The result of the construction examination showed that the possibility of the construction were confirmed, and the result of performance check test showed that it was possible to ensure the required performance of the low permeable layer, such as hydraulic conductivity. (author)

  11. Performance assessment for Nuclear Power Plant Krsko intermediate and low-level rad-waste repository; Provjera sigurnosnih performansi odlagalishta radioaktivnog otpada niske i srednje aktivnosti nuklearne elektrane Krsko

    Energy Technology Data Exchange (ETDEWEB)

    Jelavic, V [Inst. za Elektroprivredu, Zagreb. (Yugoslavia).; Tankosic, Dj [Bechtel Inc., San Francisco (United States); Skanata, D [Nuklearna elektrana Krshko, Krshko (Yugoslavia); Plecjas, I [Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia)

    1990-07-01

    Performance safety Assessment for NPP Krsko radwaste repository was performed (LLW/ILW). Shallow land and tunnel type concept were analyzed. Because it was based on two unknown referent sites, one for the shallow land concept and the other for the tunnel type, analysis was generic in nature. Scenario selecting process and consequence analysis were performed by using deterministic approach. Results for both concepts of disposal suggests that proposed NPP Krsko radwaste repository reference site and disposal technology will fully meet radiation limits imposed by the Yugoslav regulations and ICRP guidelines. (author)

  12. Process mining software repositories

    NARCIS (Netherlands)

    Poncin, W.; Serebrenik, A.; Brand, van den M.G.J.

    2011-01-01

    Software developers' activities are in general recorded in software repositories such as version control systems, bug trackers and mail archives. While abundant information is usually present in such repositories, successful information extraction is often challenged by the necessity to

  13. Breast Cancer Tissue Repository

    National Research Council Canada - National Science Library

    Iglehart, J

    1997-01-01

    The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

  14. Nuclear waste repository design and construction

    International Nuclear Information System (INIS)

    Bohlke, B.M.; Monsees, J.E.

    1987-01-01

    Extensive underground excavation will be required for construction of a mined geologic repository for nuclear waste. Hundreds of thousands of feet of drift will be required based on the conceptual layout design for each candidate nuclear waste repository. Comparison of boring and blasting excavation methods are discussed, as are special design and construction requirements (e.g., quality assurance procedures and performance assessment) for the nuclear waste repository. Comparisons are made between boring and blasting construction methods for the repository designs proposed for salt, volcanic tuff, and basalt

  15. SUBSURFACE DESIGN SUPPORT LOW THERMAL LOAD REPOSITORY (25 MTU/ACRE)

    International Nuclear Information System (INIS)

    T.M. Lahnalampi

    1999-01-01

    The objective of this document is to present a comparison between the Viability Assessment Design Layout and a 25 MTU/acre conceptual repository design. The scope of this analysis is comparing the linear dimensions and the quantities of the major design elements, for example, emplacement drifts, perimeter mains, exhaust mains, performance confirmation drifts, connecting ramps and vertical development

  16. Visual querying and analysis of large software repositories

    NARCIS (Netherlands)

    Voinea, Lucian; Telea, Alexandru

    We present a software framework for mining software repositories. Our extensible framework enables the integration of data extraction from repositories with data analysis and interactive visualization. We demonstrate the applicability of the framework by presenting several case studies performed on

  17. Reference repository design concept for bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.W.; Martin, R.W.

    1980-10-08

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

  18. Reference repository design concept for bedded salt

    International Nuclear Information System (INIS)

    Carpenter, D.W.; Martin, R.W.

    1980-01-01

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood

  19. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    International Nuclear Information System (INIS)

    C.J. Fernado

    1998-01-01

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I andC) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I andC and will typically be integrated over a data communication network. The subsurface I andC systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures

  20. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    C.J. Fernado

    1998-09-17

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

  1. 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)

    Grahm, Paer; Hagman, Patrik; Johannesson, Lars-Erik

    2012-01-01

    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

  2. The in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. Examination of backfill material using muck from URL construction

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Tanai, Kenji; Fujita, Tomoo; Sugita, Yutaka

    2016-06-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, “Geoscientific Research” and “Research and Development on Geological Disposal Technologies”, and proceeds in three overlapping phases, “Phase I: Surface-based investigations”, “Phase II: Investigations during tunnel excavation” and “Phase III: Investigations in the underground facilities”, over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) was prepared from 2013 to 2014 fiscal year at G.L.-350m gallery (Niche No.4), and heating by electric heater in simulated overpack started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal – Hydrological – Mechanical – Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. In EBS experiment, the backfill material using mixture of bentonite and muck from Horonobe URL construction was used for backfilling a part of Niche No.4. This report shows the results of properties of the backfill material, confirmation test of compaction method and making backfill material block, and so on. From these results, it was confirmed that the backfill material would satisfy target value of the permeability and the swelling pressure. (author)

  3. Total System Performance Assessment, 1993: An evaluation of the potential Yucca Mountain repository, B00000000-01717-2200-00099, Rev. 01

    International Nuclear Information System (INIS)

    Andrews, R.W.; Dale, T.F.; McNeish, J.A.

    1994-03-01

    Total System Performance Assessments are an important component in the evaluation of the suitability of Yucca Mountain, Nevada as a potential site for a mined geologic repository for the permanent disposal of high-level radioactive wastes in the United States. The Total System Performance Assessments are conducted iteratively during the site characterization to identify issues which should be addressed by the characterization and design activities as well as providing input to regulatory/licensing and programmatic decisions. During fiscal years 1991 and 1992, the first iteration of Total System Performance Assessment (hereafter referred to as TSPA 1991) was completed by Sandia National Laboratories and Pacific Northwest Laboratory. Beginning in fiscal year 1993, the Civilian Radioactive Waste Management System Management and Operating Contractor was assigned the responsibility to plan, coordinate, and contribute to the second iteration of Total System Performance Assessment (hereafter referred to as TSPA 1993). This document presents the objectives, approach, assumptions, input, results, conclusions, and recommendations associated with the Management and Operating Contractor contribution to TSPA 1993. A parallel effort was conducted by Sandia National Laboratories and is reported in Wilson et al. (1994, in press)

  4. Prestudy Oskarshamn. Tourism in Oskarshamn with or without a repository

    International Nuclear Information System (INIS)

    Nordblom, C.J.; Foghagen, C.

    1998-11-01

    Consequences for the tourism at Oskarshamn from siting a spent fuel repository in the community are studied. Four questionnaire/interview enquires were performed, and the analysis of the results show that no noticeable effects are expected. Still, an uncertainty about the impact of a repository is felt by the public, and more thorough information about the repository and its components is needed

  5. Use of simplified models in the performance assessment of a high-level waste repository system in Japan

    International Nuclear Information System (INIS)

    Pensado, Osvaldo; Mohanty, Sitakanta; Kanno, Takeshi; Tochigi, Yoshikatsu

    2005-01-01

    This paper explores simplifications to the H12 performance assessment model to enhance performance in Monte Carlo analyses. It is shown that similar reference case results to those of the H12 model can be derived by describing the buffer material surrounding a waste package as a planar body. Other possible simplifications to the performance assessment model in areas related to the stratification of the host rock transmissivity domain and solubility constraints in the buffer material are explored. (author)

  6. MTF Database: A Repository of Students' Academic Performance Measurements for the Development of Techniques for Evaluating Team Functioning

    Science.gov (United States)

    Hsiung, Chin-Min; Zheng, Xiang-Xiang

    2015-01-01

    The Measurements for Team Functioning (MTF) database contains a series of student academic performance measurements obtained at a national university in Taiwan. The measurements are acquired from unit tests and homework tests performed during a core mechanical engineering course, and provide an objective means of assessing the functioning of…

  7. Repository Rodeo Redux

    CERN Document Server

    Anez, Melissa; Donohue, Tim; Fyson, Will; Simko, Tibor; Wilcox, David

    2017-01-01

    You’ve got more repository questions and we’ve got more answers! Last year’s Repository Rodeo panel was a huge success, so we’re taking the show on the road to Brisbane for OR2017. Join representatives from the DSpace, Eprints, Fedora, Hydra, and Islandora communities as we (briefly) explain what each of our repositories actually does. We'll also talk about the directions of our respective technical and community developments, and related to the conference theme of Open: Innovation Knowledge Repositories, offer brief observations about the latest, most promising and/or most surprising innovations in our space. This panel will be a great opportunity for newcomers to Open Repositories to get a crash course on the major repository options and meet representatives from each of their communities. After a brief presentation from each representative, we'll open the session up for questions from the audience.

  8. Development of a Risk-Based Performance Assessment Method for Long-Term Cover Systems--Application to the Monticello Mill Tailings Repository

    International Nuclear Information System (INIS)

    HO, CLIFFORD K.; ARNOLD, BILL W.; COCHRAN, JOHN R.; WEBB, STEPHEN W.; TAIRA, RANDAL Y.

    2001-01-01

    A probabilistic, risk-based performance-assessment methodology is being developed to assist designers, regulators, and involved stakeholders in the selection, design, and monitoring of long-term covers for contaminated subsurface sites. This report presents an example of the risk-based performance-assessment method using a repository site in Monticello, Utah. At the Monticello site, a long-term cover system is being used to isolate long-lived uranium mill tailings from the biosphere. Computer models were developed to simulate relevant features, events, and processes that include water flux through the cover, source-term release, vadose-zone transport, saturated-zone transport, gas transport, and exposure pathways. The component models were then integrated into a total-system performance-assessment model, and uncertainty distributions of important input parameters were constructed and sampled in a stochastic Monte Carlo analysis. Multiple realizations were simulated using the integrated model to produce cumulative distribution functions of the performance metrics, which were used to assess cover performance for both present- and long-term future conditions. Performance metrics for this study included the water percolation reaching the uranium mill tailings, radon flux at the surface, groundwater concentrations, and dose. Results of this study can be used to identify engineering and environmental parameters (e.g., liner properties, long-term precipitation, distribution coefficients) that require additional data to reduce uncertainty in the calculations and improve confidence in the model predictions. These results can also be used to evaluate alternative engineering designs and to identify parameters most important to long-term performance

  9. Collection of measurement data from in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. FY2014

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Nakayama, Mariko; Kobayashi, Masato

    2015-09-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, “Geoscientific Research” and “Research and Development on Geological Disposal Technologies”, and proceeds in three overlapping phases, “Phase I: Surface-based investigations”, “Phase II: Investigations during tunnel excavation” and “Phase III: Investigations in the underground facilities”, over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at G.L.-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal – Hydrological – Mechanical – Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report summarizes the measurement data acquired from the EBS experiment from December, 2014 to March, 2015. The summarized data of the EBS experiment will be published periodically. A CD-ROM is attached as an appendix. (J.P.N)

  10. Collection of measurement data from in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. FY2015

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Nakayama, Mariko; Kobayashi, Masato

    2016-07-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, 'Geoscientific Research' and 'Research and Development on Geological Disposal Technologies', and proceeds in three overlapping phases, 'Phase I: Surface-based investigations', 'Phase II: Investigations during tunnel excavation' and 'Phase III: Investigations in the underground facilities', over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at G.L.-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal - Hydrological - Mechanical - Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report summarizes the measurement data acquired from the EBS experiment from December, 2014 to March, 2016. The summarized data of the EBS experiment will be published periodically. A CD-ROM is attached as an appendix. (J.P.N)

  11. [Screening and confirmation of 24 hormones in cosmetics by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    Science.gov (United States)

    Li, Zhaoyong; Wang, Fengmei; Niu, Zengyuan; Luo, Xin; Zhang, Gang; Chen, Junhui

    2014-05-01

    A method of ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was established to screen and confirm 24 hormones in cosmetics. Various cosmetic samples were extracted with methanol. The extract was loaded onto a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile/water containing 0.1% (v/v) formic acid for the separation. The accurate mass of quasi-molecular ion was acquired by full scanning of electrostatic field orbitrap. The rapid screening was carried out by the accurate mass of quasi-molecular ion. The confirmation analysis for targeted compounds was performed with the retention time and qualitative fragments obtained by data dependent scan mode. Under the optimal conditions, the 24 hormones were routinely detected with mass accuracy error below 3 x 10(-6) (3 ppm), and good linearities were obtained in their respective linear ranges with correlation coefficients higher than 0.99. The LODs (S/N = 3) of the 24 compounds were hormones in 50 cosmetic samples. The results demonstrate that the method is a useful tool for the rapid screening and identification of the hormones in cosmetics.

  12. CAED Document Repository

    Data.gov (United States)

    U.S. Environmental Protection Agency — Compliance Assurance and Enforcement Division Document Repository (CAEDDOCRESP) provides internal and external access of Inspection Records, Enforcement Actions, and...

  13. Administrative Data Repository (ADR)

    Data.gov (United States)

    Department of Veterans Affairs — The Administrative Data Repository (ADR) was established to provide support for the administrative data elements relative to multiple categories of a person entity...

  14. Radioactive waste repository site selection in the Republic of Slovenia

    International Nuclear Information System (INIS)

    Jeran, M.

    1992-01-01

    The report shows the procedure for the low and intermediate level radwaste (LLW and ILW) repository site selection and the work performed up to the present. The procedure for the repository site selection is divided into four steps. In the first step the unsuitable areas are excluded by taking into consideration the rough exclusion criteria. In the second step, the remaining suitable areas are screened to identify the potential sites with respect to preference criteria. In the third step three to five candidate sites will be assessed and selected among the potential sites. In the final, the fourth step, detailed site investigation and confirmation of one or two most suitable sites will follow. In Slovenia the 1st and the 2nd step of site selection have been completed, while step 3 is now in its final stage. (author) [sl

  15. Analisis Konten dan Kebijakan Akses Institutional Repository

    Directory of Open Access Journals (Sweden)

    Amirul Ulum

    2016-07-01

    Abstract; Institutional repository has become a major concern of higher education in Indonesia. The number of institutional respository was increased, one of the reason is the ranking web of repositories has been conducted by the Cybermetrics Lab in 2008. At that time, many institutions started to build institutional repository in order to manage the scientific work and also trying to reach the better ranks. Meanwhile, it is an achievement of institution performance which can be promote and increase visibility for the institution. University of Surabaya has also developed the institutional repository and managed by the library. The aims of this study is to analyze the content availability and access policies defined by the University of Surabaya repository  providing services to the academic community and external users. The method used in this study by using observations of the institutional repository University of Surabaya with a literature review to clarify the analysis of the content and access policies. The results of this study indicate that the library's role is has the authority to manage the scientific work of academic community can be done through the institutional repository. However there is still need for library to be proactive to communicate regulations on mandatory deposit of scientific work and create intensive promotion of the institutional repository.

  16. Natural Analogues - One Way to Help Build Public Confidence in the Predicted Performance of a Mined Geologic Repository for Nuclear Waste

    Energy Technology Data Exchange (ETDEWEB)

    Stuckless, J. S.

    2002-02-26

    The general public needs to have a way to judge the predicted long-term performance of the potential high-level nuclear waste repository at Yucca Mountain. The applicability and reliability of mathematical models used to make this prediction are neither easily understood nor accepted by the public. Natural analogues can provide the average person with a tool to assess the predicted performance and other scientific conclusions. For example, hydrologists with the Yucca Mountain Project have predicted that most of the water moving through the unsaturated zone at Yucca Mountain, Nevada will move through the host rock and around tunnels. Thus, seepage into tunnels is predicted to be a small percentage of available infiltration. This hypothesis can be tested experimentally and with some quantitative analogues. It can also be tested qualitatively using a variety of analogues such as (1) well-preserved Paleolithic to Neolithic paintings in caves and rock shelters, (2) biological remains preserved in caves and rock shelters, and (3) artifacts and paintings preserved in man-made underground openings. These examples can be found in materials that are generally available to the non-scientific public and can demonstrate the surprising degree of preservation of fragile and easily destroyed materials for very long periods of time within the unsaturated zone.

  17. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, Robert P.

    2014-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2008 of the performance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment-specific laboratory experiments, in-situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site-specific characterization. Because the relationship is important to understanding the evolution of the Yucca Mountain Project, the tabulation also shows the interaction between four broad categories of political bodies and government agencies/institutions: (a) technical milestones of the implementing institutions, (b) development of the regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives and decisions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste.

  18. The use of performance assessment for the potential high-level radioactive waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Lee, Joon H.; Andrews, R. W.

    1997-01-01

    This paper covers the introduction and overview of the Yucca Mountain site, the overview of waste package and EBS design, the organization of CRWMS M and O, the overview of total system performance assessment (TSPA), the components of TSPA model, the examples results of TSPA component models, and the example results of TSPA scoping sensitivity analyses. 22 figs

  19. Brine and Gas Flow Patterns Between Excavated Areas and Disturbed Rock Zone in the 1996 Performance Assessment for the Waste Isolation Pilot Plant for a Single Drilling Intrusion that Penetrates Repository and Castile Brine Reservoir

    International Nuclear Information System (INIS)

    Economy, Kathleen M.; Helton, Jon Craig; Vaughn, Palmer

    1999-01-01

    The Waste Isolation Pilot Plant (WIPP), which is located in southeastern New Mexico, is being developed for the geologic disposal of transuranic (TRU) waste by the U.S. Department of Energy (DOE). Waste disposal will take place in panels excavated in a bedded salt formation approximately 2000 ft (610 m) below the land surface. The BRAGFLO computer program which solves a system of nonlinear partial differential equations for two-phase flow, was used to investigate brine and gas flow patterns in the vicinity of the repository for the 1996 WIPP performance assessment (PA). The present study examines the implications of modeling assumptions used in conjunction with BRAGFLO in the 1996 WIPP PA that affect brine and gas flow patterns involving two waste regions in the repository (i.e., a single waste panel and the remaining nine waste panels), a disturbed rock zone (DRZ) that lies just above and below these two regions, and a borehole that penetrates the single waste panel and a brine pocket below this panel. The two waste regions are separated by a panel closure. The following insights were obtained from this study. First, the impediment to flow between the two waste regions provided by the panel closure model is reduced due to the permeable and areally extensive nature of the DRZ adopted in the 1996 WIPP PA, which results in the DRZ becoming an effective pathway for gas and brine movement around the panel closures and thus between the two waste regions. Brine and gas flow between the two waste regions via the DRZ causes pressures between the two to equilibrate rapidly, with the result that processes in the intruded waste panel are not isolated from the rest of the repository. Second, the connection between intruded and unintruded waste panels provided by the DRZ increases the time required for repository pressures to equilibrate with the overlying and/or underlying units subsequent to a drilling intrusion. Third, the large and areally extensive DRZ void volumes is a

  20. Brine and Gas Flow Patterns Between Excavated Areas and Disturbed Rock Zone in the 1996 Performance Assessment for the Waste Isolation Pilot Plant for a Single Drilling Intrusion that Penetrates Repository and Castile Brine Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    ECONOMY,KATHLEEN M.; HELTON,JON CRAIG; VAUGHN,PALMER

    1999-10-01

    The Waste Isolation Pilot Plant (WIPP), which is located in southeastern New Mexico, is being developed for the geologic disposal of transuranic (TRU) waste by the U.S. Department of Energy (DOE). Waste disposal will take place in panels excavated in a bedded salt formation approximately 2000 ft (610 m) below the land surface. The BRAGFLO computer program which solves a system of nonlinear partial differential equations for two-phase flow, was used to investigate brine and gas flow patterns in the vicinity of the repository for the 1996 WIPP performance assessment (PA). The present study examines the implications of modeling assumptions used in conjunction with BRAGFLO in the 1996 WIPP PA that affect brine and gas flow patterns involving two waste regions in the repository (i.e., a single waste panel and the remaining nine waste panels), a disturbed rock zone (DRZ) that lies just above and below these two regions, and a borehole that penetrates the single waste panel and a brine pocket below this panel. The two waste regions are separated by a panel closure. The following insights were obtained from this study. First, the impediment to flow between the two waste regions provided by the panel closure model is reduced due to the permeable and areally extensive nature of the DRZ adopted in the 1996 WIPP PA, which results in the DRZ becoming an effective pathway for gas and brine movement around the panel closures and thus between the two waste regions. Brine and gas flow between the two waste regions via the DRZ causes pressures between the two to equilibrate rapidly, with the result that processes in the intruded waste panel are not isolated from the rest of the repository. Second, the connection between intruded and unintruded waste panels provided by the DRZ increases the time required for repository pressures to equilibrate with the overlying and/or underlying units subsequent to a drilling intrusion. Third, the large and areally extensive DRZ void volumes is a

  1. Andra's geologic repository monitoring strategy

    International Nuclear Information System (INIS)

    Buschaert, S.; Lesoille, S.; Bertrand, J.; Landais, P.

    2012-01-01

    Document available in extended abstract form only. After having concluded a feasibility study of deep geological disposal for high-level and long-lived radioactive waste in 2005, Andra was charged by the Planning Act no. 2006-739 to design and create an industrial site for geological disposal called Cigeo which must be reversible for at least a century-long period. The French Safety Guide recommends that Andra develop a monitoring program to be implemented at repository construction and conducted until closure, and possibly after closure, with the aim to confirming prior expectations and enhancing knowledge of relevant processes. This abstract focuses on underground structure monitoring. The monitoring system is based on a combination of in-situ instrumentation and nondestructive methods to obtain the required level of reliable performance. To optimize the device distribution, we take into account both the repetitive design of disposal cells and the homogeneity of the rock properties. This resulted in distinguishing pilot disposal cells that are highly instrumented and standard disposal cells where the instrumentation density could be reduced; monitoring will rely mostly on robotic nondestructive evaluations. If monitoring technologies do not comply with all monitoring objectives, real withdrawal tests of high level wastes in some pilot disposal cells are also planned to provide the possibility of carrying out visual inspection, destructive analyses and samplings on construction materials. Such cells are planned to be dismantled because of the potential disturbance of their component performances from the testing process. Based on this overall strategy, Andra has analyzed the technical requirements that must be met by its monitoring equipment. First, these must be able to provide information on key THMCR (Thermal- Hydraulic-Mechanical-Chemical and Radiological) processes, to provide a three-dimensional image of a disposal component's behavior and thus to understand

  2. Nuclear waste repository siting

    International Nuclear Information System (INIS)

    Soloman, B.D.; Cameron, D.M.

    1987-01-01

    This paper discusses the geopolitics of nuclear waste disposal in the USA. Constitutional choice and social equity perspectives are used to argue for a more open and just repository siting program. The authors assert that every potential repository site inevitably contains geologic, environmental or other imperfections and that the political process is the correct one for determining sites selected

  3. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the second part of a report of a preliminary study for AECL. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) geotechnical assessment, 2) hydrogeology and waste containment, 3) thermal loading and 4) rock mechanics. (author)

  4. Methodology developed at the CEA/IPSN for logn term performance assessment of nuclear waste repositories in geological formations

    International Nuclear Information System (INIS)

    Raimbault, P.; Lewi, J.

    1985-05-01

    The CEA/ISPN is currently developing a methodology for safety evaluation of disposal site projects in granite, clay and bedded salt, host rocks formations. In the Institute of Protection and Nuclear Safety, the Department of Safety Analysis (DAS) is responsible for the coordination of the modeling effort which is performed in several specialized groups. The models are commissionned and utilized at the IPSN for specific safety evaluations. They are improved as needed and validated through international exercices (INTRACOIN-HYDROCOIN-ATKINS) and experimental programs. The DAS develops as well a global performance assessment code named MELODIE which structure allows to couple the individual models. This code participates to international joint studies such as PAGIS, in order to test its ability to model specific sites. This should help to control the adequation of the individual models to the risk assessment evaluation in order to insure the availability of specific data and to identify the most sensitive parameters. This approach should allow to coordinate the action between experimentation, code development and safety rules determination in order to be ready to perform safety assessment on chosen sites. The current status of the different aspects of this work is presented. The model development concerns mainly: transport, hydrogeology, source term, dose calculation and sensitivity studies. Its connection with data collection and model validation is stressed in the field of source modeling, hydrogeology, geochemistry and geoprospective. The description of the first version of MELODIE is presented. Some results of the interactive evaluation of the source term, the groundwater flow and the transport of radionuclides in a granite site are presented as well

  5. Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's plans for repository performance assessment

    International Nuclear Information System (INIS)

    Harrison, W.

    1984-05-01

    In the peer review of the preliminary performance assessment plan, suggestions to improve the presentation are given, technical issues are addressed, a page-by-page commentary is included, and recommendations are summarized. In the peer review of the verification and validation plan, the following are addressed: suggestions to improve presentation; key activities that have been overlooked; improving the technical content of the plan; and degree to which code documents support the plan. Comments on other supporting code documents, page-by-page commentary, and summary of recommendations are included

  6. Generic performance assessment for a deep repository for low and intermediate level waste in the UK - a case study in assessing radiological impacts on the natural environment

    International Nuclear Information System (INIS)

    Jones, S.R.; Patton, D.; Copplestone D.; Norris, S.; O'Sullivan, P.

    2003-01-01

    Concentrations of radionuclides in soil and surface water, taken from a generic performance assessment of a repository for low and intermediate level radioactive waste, assumed to be located in the UK, have been used as the basis for a case study in assessing radiological impacts on the natural environment. Simplified descriptions of the terrestrial and aquatic ecosystem types likely to be impacted have been developed. A scoping assessment has identified 226 Ra, 210 Po, 234 U, 230 Th and 238 U as having the highest potential for impact, with doses from internally incorporated alpha emitters as being potentially of particular importance. These nuclides, together with 36 Cl and 129 I (which have proved to be of importance in radiological risk assessments for humans) were included in a more detailed dose assessment. A basic methodology for dose assessment of ecosystems is described, and has been applied for the defined impacted ecosystems. Paucity of published data on concentration factors prevented a more detailed assessment for terrestrial ecosystems. For the aquatic ecosystem, a more detailed assessment was possible and highest calculated absorbed dose rates (weighted for the likely higher biological effectiveness of alpha radiation were about 6.5 μGy h -1 . We conclude that harm to the impacted ecosystems is unlikely and make the observation that the lack of concentration factor or transfer factor data for a sufficiently wide range of species, ecosystems and nuclides appears to be the principal obstacle to establishing a comprehensive framework for the application of radiological protection to ecosystems

  7. Development of Earthquake Ground Motion Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    I. Wong

    2004-01-01

    This report describes a site-response model and its implementation for developing earthquake ground motion input for preclosure seismic design and postclosure assessment of the proposed geologic repository at Yucca Mountain, Nevada. The model implements a random-vibration theory (RVT), one-dimensional (1D) equivalent-linear approach to calculate site response effects on ground motions. The model provides results in terms of spectral acceleration including peak ground acceleration, peak ground velocity, and dynamically-induced strains as a function of depth. In addition to documenting and validating this model for use in the Yucca Mountain Project, this report also describes the development of model inputs, implementation of the model, its results, and the development of earthquake time history inputs based on the model results. The purpose of the site-response ground motion model is to incorporate the effects on earthquake ground motions of (1) the approximately 300 m of rock above the emplacement levels beneath Yucca Mountain and (2) soil and rock beneath the site of the Surface Facilities Area. A previously performed probabilistic seismic hazard analysis (PSHA) (CRWMS M and O 1998a [DIRS 103731]) estimated ground motions at a reference rock outcrop for the Yucca Mountain site (Point A), but those results do not include these site response effects. Thus, the additional step of applying the site-response ground motion model is required to develop ground motion inputs that are used for preclosure and postclosure purposes

  8. Radionuclide transport in the vicinity of the repository and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Stockman, C.T.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Shinta, A.; Smith, L.N.

    2000-01-01

    The following topics related to radionuclide transport in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e. aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that no releases to the accessible environment take place due to radionuclide movement through the anhydrite marker beds, through the Dewey Lake Red Beds or directly to the surface, and also that the releases to the Culebra Dolomite are small. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for release to the Culebra Dolomite fall to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

  9. Burning of MOX fuels in LWRs; fuel history effects on thermal properties of hull and end piece wastes and the repository performance

    International Nuclear Information System (INIS)

    Hirano, Fumio; Sato, Seichi; Kozaki, Tamotsu

    2012-01-01

    The thermal impacts of hull and end piece wastes from the reprocessing of MOX spent fuels burned in LWRs on repository performance were investigated. The heat generation rates in MOX spent fuels and the resulting heat generation rates in hull and end piece wastes change depending on the history of MOX fuels. This history includes the burn-up of UO 2 spent fuels from which the Pu is obtained, the cooling period before reprocessing, the storage period of fresh MOX fuels before being loaded into an LWR, as well as the burn-up of the MOX fuels. The heat generation rates in hull and end piece wastes from the reprocessing of MOX spent fuels with any of those histories are significantly larger than those from UO 2 spent fuels with burn-ups of 45 GWd/THM. If a temperature below 80degC is specified for cement-based materials used in waste packages after disposal, the allowable number of canisters containing compacted hull and end pieces in a package for 45 and 70 GWd-MOX needs to be limited to a value of 0.4-1.6, which is significantly lower than 4.0 for 45 GWd-UO 2 . (author)

  10. Development of Earthquake Ground Motion Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, NV

    Energy Technology Data Exchange (ETDEWEB)

    I. Wong

    2004-11-05

    This report describes a site-response model and its implementation for developing earthquake ground motion input for preclosure seismic design and postclosure assessment of the proposed geologic repository at Yucca Mountain, Nevada. The model implements a random-vibration theory (RVT), one-dimensional (1D) equivalent-linear approach to calculate site response effects on ground motions. The model provides results in terms of spectral acceleration including peak ground acceleration, peak ground velocity, and dynamically-induced strains as a function of depth. In addition to documenting and validating this model for use in the Yucca Mountain Project, this report also describes the development of model inputs, implementation of the model, its results, and the development of earthquake time history inputs based on the model results. The purpose of the site-response ground motion model is to incorporate the effects on earthquake ground motions of (1) the approximately 300 m of rock above the emplacement levels beneath Yucca Mountain and (2) soil and rock beneath the site of the Surface Facilities Area. A previously performed probabilistic seismic hazard analysis (PSHA) (CRWMS M&O 1998a [DIRS 103731]) estimated ground motions at a reference rock outcrop for the Yucca Mountain site (Point A), but those results do not include these site response effects. Thus, the additional step of applying the site-response ground motion model is required to develop ground motion inputs that are used for preclosure and postclosure purposes.

  11. Approaches for treating uncertainty in the long term performance assessment of a geological waste repository in clay

    International Nuclear Information System (INIS)

    Marivoet, J.; Volckaert, G.; Wemaere, I.; Mallants, D.

    1998-01-01

    In Belgium the current strategy for high-level waste disposal is the geological disposal in a plastic clay layer. The performance assessment approach consists of a systematic scenario selection based on the FEP (features, events and processes) methodology followed by consequence analyses for the selected scenarios. In these consequence analyses the different sources of uncertainty are systematically considered. For the normal evolution scenario, i.e. the scenario which includes all FEP's which are about certain to occur, a stochastic technique of the Monte Carlo type is applied for treating uncertainty. For the altered evolution scenarios a deterministic approach is generally used to evaluate the uncertainties on the long-term. In the case of altered evolution scenarios, comparisons of fluxes from the far field into the biosphere with those calculated for the normal evolution scenario are used, beside dose calculations, to evaluate the safety consequences. Some typical examples of the above approaches will be presented. (author)

  12. Groundwater flow reference model of the Meuse/Haute-Marne region: implications on performance analysis of high and intermediate level and long lived radwaste repository in clay formation

    International Nuclear Information System (INIS)

    Benabderrahmane, H.; Plas, F.; Yven, B.; Cornaton, F.; Perrochet, P.; Kerrou, J.; Stucki, J.; Caloz, P.

    2010-01-01

    flow conditions at the bottom and at the sides of the model. - Volumetric extraction due to pumping in the Albian aquifer in the Paris region (50'000 m 3 /day). The regional flow model was calibrated with neutral faults against 1255 measured hydraulic heads. Top surface head conditions were evaluated by calibrating the inflow fluxes and the hydraulic conductivity distribution of the outcropping formations using 400 head measurements. The mean discrepancy between the measured and computed values is less than 9 m. At local scale, a reference flow model of the Oxfordian and Dogger aquifers, respectively overlaying and underlaying the Callovo-Oxfordian host formation, is calibrated against measured hydraulic heads at Andra boreholes and the flow fields of these aquifers at sector scale derived from hydrogeologic, geologic and seismic data acquired from the last site investigation campaign (2007-2008). It includes the hydraulically active faults of Marne and Poissons as well as the less active faults of Gondrecourt. The parameterization that characterize the hydrogeological role of these faults leads to the calibration of the flow with a mean discrepancy between computed and measured values less than 3 m. The performance analysis of the repository emplacement within the 250 km 2 Andra site area was carried out using the stationary velocity field of this reference flow model and computing (i) the travel time and cumulative distance of purely advective particle trajectories and (ii) the lifetime expectancy of water molecules crossing the waste repository and migrating by hydro-dispersive motion (advection, dispersion and diffusion) through the 3-D structures towards the outlets of the aquifer system, using the method proposed by Cornaton and Perrochet. The corrosion of metals contained in intermediate level waste under reduced chemical conditions will lead to the production of hydrogen gas during the post closure phase of a radioactive waste repository. A rough

  13. Ultra-high performance liquid chromatography-tandem mass spectrometry in high-throughput confirmation and quantification of 34 anabolic steroids in bovine muscle.

    Science.gov (United States)

    Vanhaecke, Lynn; Vanden Bussche, Julie; Wille, Klaas; Bekaert, Karen; De Brabander, Hubert F

    2011-08-26

    An ultra-high performance liquid chromatography tandem mass spectrometry multi-residue method for the determination of 34 anabolic steroids (10 estrogens including stilbenes, 14 androgens and 10 gestagens) in meat of bovine origin is reported. The extraction and clean-up procedure involved homogenization with methanol, defatting with hexane, liquid/liquid extraction with diethylether and finally SPE clean-up with coupled Si and NH(2) cartridges. The analytes were separated on a 1.9 μm Hypersil Gold column (100×2.1 mm) and quantified on a triple quadrupole mass spectrometer (TSQ Vantage) operating simultaneously in both positive and negative atmospheric pressure chemical ionisation (APCI) modes. This analytical procedure was subsequently validated according to EU criteria (CD 2002/657/EC), resulting in decision limits and detection capabilities ranging between 0.04 and 0.88 μg kg(-1) and 0.12 and 1.9 μg kg(-1), respectively. The method obtained for all, natural and synthetic steroids, adequate precisions and intra-laboratory reproducibilities (relative standard deviation below 20%), and the linearity ranged between 0.991 and 0.999. The performance characteristics fulfill the recommended concentrations fixed by the Community Reference Laboratories. The developed analysis is sensitive, and robust and therefore useful for confirmation and quantification of anabolic steroids for research purposes and residue control programs. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Confirmation of congenital adrenal hyperplasia by adrenal steroid profiling of filter paper dried blood samples using ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rossi, Claudia; Calton, Lisa; Brown, Heather A; Gillingwater, Scott; Wallace, A Michael; Petrucci, Francesca; Ciavardelli, Domenico; Urbani, Andrea; Sacchetta, Paolo; Morris, Michael

    2011-04-01

    The specificity of screening for congenital adrenal hyperplasia by direct measurement of 17-hydroxyprogesterone in filter paper dried blood spot samples by immunoassay is low and has a high false-positive rate. In order to reduce the false-positive rate of this test, we developed a rapid, robust, specific confirmatory procedure in which cortisol, 4-androstene-3,17-dione and 17-hydroxyprogesterone were measured simultaneously by ultra-performance liquid chromatography-tandem mass spectrometry. After extraction, samples were analysed by ultra-performance liquid chromatography-tandem mass spectrometry and 17-hydroxyprogesterone was quantified accurately. Other steroids were determined using stable deuterated internal standards. In total, 25 patient blood spot samples and 92 control samples were analysed. The assay was linear for 17-hydroxyprogesterone, with a coefficient of determination >0.997 and imprecision ≤ 6.5%. An upper limit of normal for 17-hydroxyprogester-one of 4.45 nmol/L was established by analysing a cohort of samples from unaffected newborns. In addition, a cut-off of 3.5 for the peak areas ratio (17-hydroxyprogesterone+4-androstene-3,17-dione)/cortisol, allows confirmation of the affected steroidogenic enzyme. A high throughput method for the detection of steroids related to congenital adrenal hyperplasia has been developed, allowing the false-positive rate associated with screening for 17-hydroxyprogesterone by immunoassay to be determined.

  15. Retrieval effects on ventilation and cooling requirements for a nuclear waste repository

    International Nuclear Information System (INIS)

    Hambley, D.F.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the regulations promulgated in Title 10, Part 60 of the Code of Federal Regulations (10CFR60) by the US Nuclear Regulatory Commission (NRC) for an underground repository for spent fuel and high level nuclear waste (HLW) require that it is possible to retrieve waste, for whatever reason, from such a facility for a period of 50 years from initial storage or until the completion of the performance confirmation period, whichever comes first. This paper considers the effects that the retrievability option mandates on ventilation and cooling systems required for normal repository operations. An example is given for a hypothetical repository in salt. 18 refs., 1 tab

  16. Wireless Transmission of Monitoring Data out of an Underground Repository: Results of Field Demonstrations Performed at the HADES Underground Laboratory - 13589

    International Nuclear Information System (INIS)

    Schroeder, T.J.; Rosca-Bocancea, E.; Hart, J.

    2013-01-01

    As part of the European 7. framework project MoDeRn, Nuclear Research and Consultancy Group (NRG) performed experiments in order to demonstrate the feasibility of wireless data transmission through the subsurface over large distances by low frequency magnetic fields in the framework of the geological disposal of radioactive waste. The main objective of NRG's contribution is to characterize and optimize the energy use of this technique within the specific context of post-closure monitoring of a repository. For that, measurements have been performed in the HADES Underground Research Laboratory (URL) located at Mol, Belgium, at 225 m depth. The experimental set-up utilizes a loop antenna for the transmitter that has been matched to the existing infrastructure of the HADES. Between 2010 and 2012 NRG carried out several experiments at the HADES URL in order to test the technical set-up and to characterize the propagation behavior of the geological medium and the local background noise pattern. Transmission channels have been identified and data transmission has been demonstrated at several frequencies, with data rates up to 10 bit/s and bit error rates <1%. A mathematical model description that includes the most relevant characteristics of the transmitter, transmission path, and receiver has been developed and applied to analyze possible options to optimize the set-up. With respect to the energy-efficiency, results so far have shown that data transmission over larger distances through the subsurface is a feasible option. To support the conclusions on the energy need per bit of transmitted data, additional experiments are foreseen. (authors)

  17. Far-field sorption data bases for performance assessment of a L/ILW repository in an undisturbed Palfris marl host rock

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Baeyens, B.

    1997-12-01

    A Palfris marl formation at Wellenberg (Gemeinde Wolfenschiessen, NW) has been chosen by NAGRA as a potential repository site for low- and intermediate-level radioactive waste, L/ILW. In the coming years a series of performance assessment studies will be performed for this site. One set of key data required for such safety analysis calculations is sorption data bases (SDB) for safety relevant radionuclides in the far-field. The purpose of this report is to describe the procedures used to generate sorption data bases appropriate for the in situ conditions existing along the different potential flow paths in an undisturbed marl host rock formation. An important aim was to document the sources of sorption data used and, in particular, the processes by which data selections were mad.e. The main guiding principles here were 'transparency' and 'traceability'. Inherent within this whole process is also the justification for, and defensibility of, the selected values. Much of the sorption data used to generate the SDB for marl came from the open literature. A major part of this report is concerned with describing the procedures whereby these initial literature values are modified so that they apply to the actual marl mineralogies and groundwater chemistries. The resulting 'reference R d values' are then further modified using so called Lab -> Field transfer factors to produce sorption values which are appropriate to the in situ bulk rock conditions. The Lab -> Field transfer factors attempt to correct for the differences in sorption site availability between the crushed rock state used in batch tests and the intact rock state existing in reality in the host rock. There are two main groundwater chemistries and five characteristic mineralogical compositions which cover the three broad types of flow paths which have been identified in the Palfris marl formation. In principle the methodology described here to construct sorption data bases for marl is applicable to any type of

  18. Far-field sorption data bases for performance assessment of a L/ILW repository in an undisturbed Palfris marl host rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.H.; Baeyens, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-12-01

    A Palfris marl formation at Wellenberg (Gemeinde Wolfenschiessen, NW) has been chosen by NAGRA as a potential repository site for low- and intermediate-level radioactive waste, L/ILW. In the coming years a series of performance assessment studies will be performed for this site. One set of key data required for such safety analysis calculations is sorption data bases (SDB) for safety relevant radionuclides in the far-field. The purpose of this report is to describe the procedures used to generate sorption data bases appropriate for the in situ conditions existing along the different potential flow paths in an undisturbed marl host rock formation. An important aim was to document the sources of sorption data used and, in particular, the processes by which data selections were mad.e. The main guiding principles here were `transparency` and `traceability`. Inherent within this whole process is also the justification for, and defensibility of, the selected values. Much of the sorption data used to generate the SDB for marl came from the open literature. A major part of this report is concerned with describing the procedures whereby these initial literature values are modified so that they apply to the actual marl mineralogies and groundwater chemistries. The resulting `reference R{sub d} values` are then further modified using so called Lab -> Field transfer factors to produce sorption values which are appropriate to the in situ bulk rock conditions. The Lab -> Field transfer factors attempt to correct for the differences in sorption site availability between the crushed rock state used in batch tests and the intact rock state existing in reality in the host rock. There are two main groundwater chemistries and five characteristic mineralogical compositions which cover the three broad types of flow paths which have been identified in the Palfris marl formation. In principle the methodology described here to construct sorption data bases for marl is applicable to any

  19. Non-Text Theses as an Integrated Part of the University Repository: a Case Study of the Academy of Performing Arts in Prague

    Directory of Open Access Journals (Sweden)

    Iva Horová

    2010-09-01

    Full Text Available Training the professional artists of the future brings several challenges. Students at the Academy of Performing Arts in Prague (AMU, at all degree levels, are required to produce outputs including several final qualifying works. A piece of written work is mandatory, but this is usually accompanied by records of artistic performance — a graduation film, a stage role, graphic materials, a concert, a set of photographs, etc. Each of these works has its own topic, tutor, opponents, annotations and even classifications. Some qualifying works, such as films, can have multiple student input, with different graduands in the roles of screenwriter, director, producer, and so on. The preservation and discovery of and access to these works are issues of obvious importance, just as is the case with ‘traditional’ textual works. These issues were addressed at AMU by modifications to an Open Source system, DSpace. Metadata based on the Dublin Core Standard was extended to include the relation element qualifiers. The modules for editing and displaying were modified to permit searching and viewing of the related documents. Video and audio players were integrated into the system to make the related multimedia files available directly from the primary record page. A handle server, which generates persistent identifiers, was implemented. The automatic transfer of metadata from the AMU Study information system, KOS, into the repository was enabled, along with automated OAI-PMH harvesting into the national registry Theses.cz at Masaryk University in Brno, and exports into the AMU library system. This paper is based on a presentation given by the lead author at the 2010 LIBER Annual General Conference, Aarhus, as part of the DART-Europe Master Class on the management of electronic theses.

  20. Gas generation in repositories

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.; McGahan, D.; Rushbrook, P.E.

    1987-09-01

    The nature and quantities of gases likely to be produced by various processes in repositories for low level and intermediate level radioactive wastes are examined in this preliminary study. Many simplifying assumptions are made where published or experimental data is unavailable. The corrosion of the canisters and metallic components in wastes is likely to be the major gas production process in both types of repository. A significant contribution from microbiological activity is expected to occur in low level repositories, predominantly where no cement grouting of the cans has been carried out. A number of areas for further research, required before a more comprehensive study could be carried out, have been identified. (author)

  1. Centralized mouse repositories.

    Science.gov (United States)

    Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

    2012-10-01

    Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

  2. Experimental investigation of hydrous pyrolysis of diesel fuel and the effect of pyrolysis products on performance of the candidate nuclear waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Jackson, K.J.; Carroll, S.A.

    1994-01-01

    It is thought that a significant amount of diesel fuel and other hydrocarbon-rich phases may remain inside the candidate nuclear waste repository at Yucca Mountain after construction and subsequent emplacement of radioactive waste. Although the proposed repository horizon is above the water table, the remnant hydrocarbon phases may react with hydrothermal solutions generated by high temperature conditions that will prevail for a period of time in the repository. The preliminary experimental results of this study show that diesel fuel hydrous pyrolysis is minimal at 200 degrees C and 70 bars. The composition of the diesel fuel remained constant throughout the experiment and the concentration of carboxylic acids in the aqueous phases was only slightly above the detection limit (1-2 ppm) of the analytical technique

  3. The Radiological and Thermal Characteristics of Fission Waste from a Deep-Burn Fusion-Fission Hybrid (LIFE) and Implications for Repository Performance

    International Nuclear Information System (INIS)

    Shaw, H.F.; Blink, J.; Farmer, J.; Latkowski, J.; Kramer, K.

    2009-01-01

    photon transport calculations were performed using MCNP5. Burnup calculations were performed using a modified version of Monteburns 2.0. The nuclear data used were from ENDF/B-VII. Additional details of the burn calculations can be found in. For comparison to spent fuel from light water reactors (LWRs), we use the projected initial inventory of PWR and BWR fuels (current average age of 23 years since discharge) used for the Yucca Mountain Project Final Environmental Impact Statement. The decay of this initial inventory to 1 million years was calculated using ORIGEN2. The hybrid system considered here would have generated ∼44 GWe-yr of energy at 99% FIMA. The energy generated per MT is therefore about 1100 MWe-yr/MT. In contrast, using average burnups of 41.2 GWt-day/MT and 33.6 GWt-day/MT for the PWR and BWR fuel slated for disposal at Yucca Mtn., and assuming a thermal electric conversion efficiency of ∼33%, the total energy generated by the 68,000 MT 'Yucca Mtn. inventory' is ∼2500 GWe-yr, or ∼37 MWe-yr/MT, which is ∼30 times less energy per MT than the waste from the hybrid. Clearly, relative to the current once-through fuel cycle, the use of a deep-burn hybrid to generate electricity would significantly reduce the need for repository capacity.

  4. Impact of adaptation algorithm, timing, and stopping boundaries on the performance of Bayesian response adaptive randomization in confirmative trials with a binary endpoint.

    Science.gov (United States)

    Jiang, Yunyun; Zhao, Wenle; Durkalski-Mauldin, Valerie

    2017-11-01

    Despite the concerns of time trend in subject profiles, the use of Bayesian response adaptive randomization (BRAR) in large multicenter phase 3 confirmative trials has been reported in recent years, motivated by the potential benefits in subject ethics and/or trial efficiency. However three issues remain unclear to investigators: 1) among several BRAR algorithms, how to choose one for the specific trial setting; 2) when to start and how frequently to update the allocation ratio; and 3) how to choose the interim analyses stopping boundaries to preserve the type 1 error. In this paper, three commonly used BRAR algorithms are evaluated based on type 1 error, power, sample size, the proportion of subjects assigned to the better performing arm, and the total number of failures, under two specific trial settings and different allocation ratio update timing and frequencies. Simulation studies show that for two-arm superiority trials, none of the three BRAR algorithms has predominant benefits in both patient ethics and trial efficiency when compared to fixed equal allocation design. For a specific trial aiming to identify the best or the worst among three treatments, a properly selected BRAR algorithm and its implementation parameters are able to gain ethical and efficiency benefits simultaneously. Although the simulation results come from a specific trial setting, the methods described in this paper are generally applicable to other trials. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. National Radwaste Repository Mochovce

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the National Radioactive Waste Repository in Mochovce (Repository) is described. The Mochovce National Radioactive Waste Repository is a surface multi-barrier type storage facility for solid and treated solidified radioactive wastes generated from the Slovak Republic nuclear power plants operation and decommissioning, research institutes, laboratories and hospitals. The Repository comprises a system of single- and double-row storage boxes. The first double-row is enclosed by a steel-structure building. The 18 x 6 x 5.5 m storage boxes are made of reinforced concrete. The wall thickness is 600 mm. Two-double-rows, i.e. 80 storage boxes were built as part of Stage I (1 row = 20 storage boxes). Each storage box has a storage capacity of 90 fibre concrete containers of 3.1 m 3 volume. The total storage capacity is 7200 containers with the overall storage volume of 22320 m 3

  6. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  7. NIDDK Central Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

  8. Repository development status in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Beceiro, Alvaro; Zuloaga, Pablo [ENRESA (Spain)

    2009-06-15

    The paper describes the status of repository development for the different waste categories. Low and Intermediate Waste Disposal facility of El Cabril was commissioned in 1992 and is in normal operation. The major modifications and activities during the last years are the adaptation to waste streams not initially foreseen such as some decommissioning waste or waste from steel industry, and the improvement of its performance assessment, supported by a R and D and refined models. As part of this facility, a new disposal facility specifically intended for very low activity waste has been constructed and commissioned in July 2008. Its design is based on the European Directive for hazardous waste disposal. National policy for Nuclear Spent Fuel and High-Level waste is focused on the development of a centralized storage facility of the vault type, whose site location would be selected through a volunteering process. Meanwhile, with the aim of solving specific problems, three individual storage facilities are in different status at reactor sites. Research on final solution, including some repository aspects as well as separation and transmutation are being carried out in accordance to ENRESA's R and D program. ENRESA has developed conceptual designs for non site specific repositories, both in granite and clay, and has carried out their corresponding performance assessment exercises. (authors)

  9. Managing and Evaluating Digital Repositories

    Science.gov (United States)

    Zuccala, Alesia; Oppenheim, Charles; Dhiensa, Rajveen

    2008-01-01

    Introduction: We examine the role of the digital repository manager, discuss the future of repository management and evaluation and suggest that library and information science schools develop new repository management curricula. Method: Face-to-face interviews were carried out with managers of five different types of repositories and a Web-based…

  10. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the first part of a report of a preliminary study for Atomic Energy of Canada Limited. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) underground layout, 2) cost estimates, 3) waste handling, 4) retrievability, decommissioning, sealing and monitoring, and 5) research and design engineering requirements. (author)

  11. Preliminary design of the repository, stage 2

    International Nuclear Information System (INIS)

    Saanio, T.; Kirkkomaeki, T.; Keto, P.; Kukkola, T.; Raiko, H.

    2007-01-01

    Spent nuclear fuel from Finnish nuclear power plants will be disposed of in deep bedrock in Olkiluoto, Eurajoki. The repository is planned to be excavated at a depth of 400 - 500 metres. Access routes to the repository include a 1:10 inclined access tunnel, and vertical shafts. The fuel is encapsulated in the encapsulation plant above ground and transferred to the repository in the canister lift. Deposition tunnels, central tunnels and technical rooms are excavated at the disposal level. The canisters are deposited in deposition holes that are covered with bentonite blocks. The deposition holes are bored in the floors of the deposition tunnels. The central tunnel system consists of two parallel central tunnels that are inter-connected at certain distances. Two parallel central tunnels improve the fire safety of the rooms and also allow flexible backfilling and closing of the deposition tunnels in stages at the operational phase of the repository. An underground rock characterization facility, ONKALO, is excavated at the disposal level to support and confirm investigations carried out from above ground. ONKALO is designed so that it can later serve as part of the repository. ONKALO excavations were started in 2004. The repository will be excavated in the 2010s and operation will start in 2020. The fifth nuclear power unit makes the operational phase of the repository very long. Parts of the repository will be excavated and closed over the long operational period. The repository can be constructed at one or several levels. The one-storey alternative is the so-called reference alternative in this preliminary design report. The two-storey alternative is also taken into account in the ONKALO designs. The preliminary designs of the repository are presented as located in Olkiluoto. The location of the repository will be revised when more information on the bedrock has been gained. More detailed data of the circumstances will be obtained from above ground investigations

  12. Preliminary design of the repository. Stage 2

    International Nuclear Information System (INIS)

    Saanio, T.; Kirkkomaeki, T.; Keto, P.; Kukkola, T.; Raiko, H.

    2007-04-01

    Spent nuclear fuel from Finnish nuclear power plants will be disposed of in deep bedrock in Olkiluoto, Eurajoki. The repository is planned to be excavated at a depth of 400 - 500 metres. Access routes to the repository include a 1:10 inclined access tunnel, and vertical shafts. The fuel is encapsulated in the encapsulation plant above ground and transferred to the repository in the canister lift. Deposition tunnels, central tunnels and technical rooms are excavated at the disposal level. The canisters are deposited in deposition holes that are covered with bentonite blocks. The deposition holes are bored in the floors of the deposition tunnels. The central tunnel system consists of two parallel central tunnels that are inter-connected at certain distances. Two parallel central tunnels improve the fire safety of the rooms and also allow flexible backfilling and closing of the deposition tunnels in stages at the operational phase of the repository. An underground rock characterization facility, ONKALO, is excavated at the disposal level to support and confirm investigations carried out from above ground. ONKALO is designed so that it can later serve as part of the repository. ONKALO excavations were started in 2004. The repository will be excavated in the 2010s and operation will start in 2020. The fifth nuclear power unit makes the operational phase of the repository very long. Parts of the repository will be excavated and closed over the long operational period. The repository can be constructed at one or several levels. The one-storey alternative is the so-called reference alternative in this preliminary design report. The two-storey alternative is also taken into account in the ONKALO designs. The preliminary designs of the repository are presented as located in Olkiluoto. The location of the repository will be revised when more information on the bedrock has been gained. More detailed data of the circumstances will be obtained from above ground investigations

  13. Repository operational criteria analysis

    International Nuclear Information System (INIS)

    Hageman, J.P.; Chowdhury, A.H.

    1992-08-01

    The objective of the ''Repository Operational Criteria (ROC) Feasibility Studies'' (or ROC task) was to conduct comprehensive and integrated analyses of repository design, construction, and operations criteria in 10 CFR Part 60 regulations, considering the interfaces and impacts of any potential changes to those regulations. The study addresses regulatory criteria related to the preclosure aspects of the geologic repository. The study task developed regulatory concepts or potential repository operational criteria (PROC) based on analysis of a repository's safety functions and other regulations for similar facilities. These regulatory concepts or PROC were used as a basis to assess the sufficiency and adequacy of the current criteria in 10 CFR Part 60. Where the regulatory concepts were same as current operational criteria, these criteria were referenced. The operations criteria referenced or the PROC developed are given in this report. Detailed analyses used to develop the regulatory concepts and any necessary PROC for those regulations that may require a minor change are also presented. The results of the ROC task showed a need for further analysis and possible major rule change related to the design bases of a geologic repository operations area, siting, and radiological emergency planning

  14. Compliance demonstration: What can be reasonably expected from safety assessment for geological repositories?

    International Nuclear Information System (INIS)

    Zuidema, P.; Smith, P.; Sumerling, T.

    1999-01-01

    When licensing a nuclear facility, it is important to demonstrate that it will comply with regulatory limits (e.g. individual dose limits) and also show that sufficient attention has been paid to optimisation of facility design and operation, such that any associated radiological impacts will be as low as reasonably achievable (ALARA). In general, in demonstrating compliance, experience can be drawn from the performance of existing and similar facilities, and monitoring plans can be specified that will confirm that actual radiological discharges during operations are within authorised limits for the facility. This is also true in respect of the operational period of a geological repository. For the post-closure phase of a repository, however, it is also necessary to show that possible releases will remain acceptably low even at long times in the future when, it is assumed, control of the facility has lapsed and there is no method of either monitoring releases or taking remedial action in the case of unexpected events or releases. In addition, within each country, a deep geological repository will be a first-of-a-kind development so that compliance arguments can be expected to be rigorously tested without any assistance from the precedent of licensing of similar facilities nationally. This puts heavy, and quite unusual, burdens on the long-term safety assessment for a geological repository to develop a case that is sufficiently strong to demonstrate compliance. This paper focuses on the problem of demonstrating compliance with long-term safety requirements for a geological repository, and explores: the overall aims and special difficulties of demonstrating compliance for a geological repository; the role of safety assessment in demonstrating compliance; the scope for optimisation of a geological repository and importance of robustness and lessons learnt from the application of safety assessment. In addition, some issues requiring further discussion and clarification

  15. A Socio-Technical Perspective on Repository Monitoring - 12229

    Energy Technology Data Exchange (ETDEWEB)

    Bergmans, Anne [University of Antwerp, Faculty of Political and Social Sciences, Sint-Jacobstraat 2, 2000 Antwerpen (Belgium); Elam, Mark; Sundqvist, Goeran [University of Gothenburg, Department of Sociology, Box 720, 40530 Gothenburg (Sweden); Simmons, Peter [University of East Anglia, School of Environmental Sciences, Norwich NR4 7TJ (United Kingdom)

    2012-07-01

    Monitoring geological repositories for high-activity radioactive wastes has both technical and social dimensions, which are closely interrelated. To investigate the implications of this for geological disposal, data on experts' expectations of repository monitoring and the functions that it is expected to serve were analysed. The analysis drew on strategic and technical documents on monitoring produced by national agencies and by international organisations or projects; interviews with specialists in radioactive waste management organisations on monitoring and on their perceptions of societal concerns and expectations; and observations from technical workshops on repository monitoring. Three main rationales for monitoring were found: performance confirmation; decision support in a step-wise process; and public and stakeholder confidence building. The expectation that monitoring will enhance public confidence is then examined from a social scientific perspective and the potential for and challenges to using monitoring in this way are reviewed. In conclusion, implications for stakeholder engagement in the development of monitoring objectives and strategies are discussed. (authors)

  16. Determining redox properties of clay-rich sedimentary deposits in the context of performance assessment of radioactive waste repositories : Conceptual and practical aspects

    NARCIS (Netherlands)

    Behrends, T.; Bruggeman, Christophe

    Redox reactions play a key factor controlling the mobility of redox sensitive radionuclides in clay-rich sediments which might serve as host formations for radioactive waste repositories. Assessing the redox speciation of radionuclides requires information about the redox conditions in the formation

  17. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    Bradburry, M.; Baeyens, B.

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P CO 2 . In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab→Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some appreciation of the uncertainties

  18. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradburry, M.; Baeyens, B

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P{sub CO{sub 2}}. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab{yields}Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some

  19. Hydraulic/mechanical modeling of smectitic materials for HMC analytical evaluation of the long term performance of TRU geological repository - 59090

    International Nuclear Information System (INIS)

    Kobayashi, Ichizo; Owada, Hitoshi; Ishii, Tomoko

    2012-01-01

    Aiming at evaluation of the long term performance of transuranic (TRU) geological repositories, the hydraulic/ mechanical/chemical (HMC) analysis method has been studied. In this phase of research (four years) the hydraulic/mechanical modeling of smectitic materials for HMC analyses has been studied. In this paper, new experimental methods for investigation of the hydraulic/mechanical behavior of smectitic materials were developed. For hydraulic modeling, the measurement method of the specific surface area of compacted smectitic materials was developed using X-ray diffraction (XRD). The results of the method were applied to the Kozeny-Carman law. Since the specific surface area represents the microstructure of smectitic materials such as the degree of swelling, it was found that the Kozeny-Carman law using measured specific surface area of compacted smectitic materials was useful in evaluating the hydraulic performance of smectitic materials. Moreover, since the Kozeny-Carman law can take the alteration of content of pore water into consideration by not only a coefficient of viscosity but also by changes in specific surface area, the Kozeny-Carman law will be more suitable to chemical and mechanical couple analyses than the ordinary Darcy's law. For the mechanical modeling, the procedure of one dimensional exhausting compression test was developed. The tests gave the dry density and compression stress relation in the state of full-saturation of smectitic materials with varying water content. The relations between the dry density and compression stress in the state of fully saturation were termed fully saturation lines. The group of iso-grams of degree of saturation and water content were also given with this test. It was found that the fully-saturation line is consistent with swelling deformation-pressure relation in the equilibrium state. The results indicated that the swelling deformation-pressure relation does not depend on the saturation manner, such as the

  20. Geotechnical instrumentation for repository shafts

    International Nuclear Information System (INIS)

    Lentell, R.L.; Byrne, J.

    1993-01-01

    The US Congress passed the Nuclear Waste Policy Act in 1980, which required that three distinctly different geologic media be investigated as potential candidate sites for the permanent disposal of high-level nuclear waste. The three media that were selected for study were basalt (WA), salt (TX, LA, MS, UT), and tuff (NV). Preliminary Exploratory Shaft Facilities (ESF) designs were prepared for seven candidate salt sites, including bedded and domal salt environments. A bedded-salt site was selected in Deaf Smith County, TX for detailed site characterization studies and ESF Final Design. Although Congress terminated the Salt Repository Program in 1988, Final Design for the Deaf Smith ESF was completed, and much of the design rationale can be applied to subsequent deep repository shafts. This paper presents the rationale for the geotechnical instrumentation that was designed for construction and operational performance monitoring of the deep shafts of the in-situ test facility. The instrumentation design described herein can be used as a general framework in designing subsequent instrumentation programs for future high-level nuclear waste repository shafts

  1. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1993-02-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This Paper describes a mathematical model design to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (author)

  2. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1992-07-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

  3. Trust in Digital Repositories

    Directory of Open Access Journals (Sweden)

    Elizabeth Yakel

    2013-06-01

    Full Text Available ISO 16363:2012, Space Data and Information Transfer Systems - Audit and Certification of Trustworthy Digital Repositories (ISO TRAC, outlines actions a repository can take to be considered trustworthy, but research examining whether the repository’s designated community of users associates such actions with trustworthiness has been limited. Drawing from this ISO document and the management and information systems literatures, this paper discusses findings from interviews with 66 archaeologists and quantitative social scientists. We found similarities and differences across the disciplines and among the social scientists. Both disciplinary communities associated trust with a repository’s transparency. However, archaeologists mentioned guarantees of preservation and sustainability more frequently than the social scientists, who talked about institutional reputation. Repository processes were also linked to trust, with archaeologists more frequently citing metadata issues and social scientists discussing data selection and cleaning processes. Among the social scientists, novices mentioned the influence of colleagues on their trust in repositories almost twice as much as the experts. We discuss the implications our findings have for identifying trustworthy repositories and how they extend the models presented in the management and information systems literatures.

  4. CERN confirms LHC schedule

    CERN Document Server

    2003-01-01

    The CERN Council held its 125th session on 20 June. Highlights of the meeting included confirmation that the LHC is on schedule for a 2007 start-up, and the announcement of a new organizational structure in 2004.

  5. Supplemental Performance Analyses for Igneous Activity and Human Intrusion at the Potential High-Level Nuclear Waste Repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Swift, P.; Gaither, K.; Freeze, G.; McCord, J.; Kalinich, D.; Saulnier, G.; Statham, W.

    2002-01-01

    The U.S. Department of Energy (DOE) is considering the possible recommendation of a site at Yucca Mountain, Nevada, for the potential development of a geologic repository for the disposal of high-level radioactive waste and spent nuclear fuel. Consequences of hypothetical disruption of the Yucca Mountain site by igneous activity or human intrusion have been evaluated in the Yucca Mountain Science and Engineering Report (S and ER) (1), which presents technical information supporting the consideration of the possible site recommendation. Since completion of the S and ER, supplemental analyses have examined possible impacts of new information and alternative assumptions on the estimates of the consequences of these events. Specifically, analyses of the consequences of igneous disruption address uncertainty regarding: (1) the impacts of changes in the repository footprint and waste package spacing on the probability of disruption; (2) impacts of alternative assumptions about the appropriate distribution of future wind speeds to use in the analysis; (3) effects of alternative assumptions about waste particle sizes; and (4) alternative assumptions about the number of waste packages damaged by igneous intrusion; and (5) alternative assumptions about the exposure pathways and the biosphere dose conversion factors used in the analysis. Additional supplemental analyses, supporting the Final Environmental Impact Statement (FEIS), have examined the results for both igneous disruption and human intrusion, recalculated for a receptor group located 18 kilometers (km) from the repository (the location specified in 40 CFR 197), rather than at the 20 km distance used in the S and ER analyses

  6. Illustration of sampling-based approaches to the calculation of expected dose in performance assessments for the proposed high level radioactive waste repository at Yucca Mountain, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Helton, Jon Craig (Arizona State University, Tempe, AZ); Sallaberry, Cedric J. PhD. (.; .)

    2007-04-01

    A deep geologic repository for high level radioactive waste is under development by the U.S. Department of Energy at Yucca Mountain (YM), Nevada. As mandated in the Energy Policy Act of 1992, the U.S. Environmental Protection Agency (EPA) has promulgated public health and safety standards (i.e., 40 CFR Part 197) for the YM repository, and the U.S. Nuclear Regulatory Commission has promulgated licensing standards (i.e., 10 CFR Parts 2, 19, 20, etc.) consistent with 40 CFR Part 197 that the DOE must establish are met in order for the YM repository to be licensed for operation. Important requirements in 40 CFR Part 197 and 10 CFR Parts 2, 19, 20, etc. relate to the determination of expected (i.e., mean) dose to a reasonably maximally exposed individual (RMEI) and the incorporation of uncertainty into this determination. This presentation describes and illustrates how general and typically nonquantitive statements in 40 CFR Part 197 and 10 CFR Parts 2, 19, 20, etc. can be given a formal mathematical structure that facilitates both the calculation of expected dose to the RMEI and the appropriate separation in this calculation of aleatory uncertainty (i.e., randomness in the properties of future occurrences such as igneous and seismic events) and epistemic uncertainty (i.e., lack of knowledge about quantities that are poorly known but assumed to have constant values in the calculation of expected dose to the RMEI).

  7. Socioeconomic impacts of repositories

    International Nuclear Information System (INIS)

    Thomas, J.K.; Hamm, R.R.; Murdock, S.H.

    1983-01-01

    Federal and state decision makers, community leaders, and residents must know how communities will be changed by the impacts of a high-level nuclear waste repository. This chapter identifies the factors affecting an assessment of socioeconomic impacts and the types of impacts (economic, demographic, fiscal, community service, and social) likely to occur as a result of repository development. Each of these types can be divided into standard (those which typically results from any large-scale development) and special impact categories (those which result from the fact that radioactive materials will be handled). 3 tables

  8. Safeguards for geological repositories

    International Nuclear Information System (INIS)

    Fattah, A.

    2000-01-01

    Direct disposal of spent nuclear fuel in geological repositories is a recognised option for closing nuclear fuel cycles. Geological repositories are at present in stages of development in a number of countries and are expected to be built and operated early next century. A State usually has an obligation to safely store any nuclear material, which is considered unsuitable to re-enter the nuclear fuel cycle, isolated from the biosphere. In conjunction with this, physical protection has to be accounted for to prevent inadvertent access to such material. In addition to these two criteria - which are fully under the State's jurisdiction - a third criterion reflecting international non-proliferation commitments needs to be addressed. Under comprehensive safeguards agreements a State concedes verification of nuclear material for safeguards purposes to the IAEA. The Agency can thus provide assurance to the international community that such nuclear material has been used for peaceful purposes only as declared by the State. It must be emphasised that all three criteria mentioned constitute a 'unit'. None can be sacrificed for the sake of the other, but compromises may have to be sought in order to make their combination as effective as possible. Based on comprehensive safeguards agreements signed and ratified by the State, safeguards can be terminated only when the material has been consumed or diluted in such a way that it can no longer be utilised for any nuclear activities or has become practicably irrecoverable. As such safeguards for nuclear material in geological repositories have to be continued even after the repository has been back-filled and sealed. The effective application of safeguards must assure continuity-of-knowledge that the nuclear material in the repository has not been diverted for an unknown purpose. The nuclear material disposed in a geological repository may eventually have a higher and long term proliferation risk because the inventory is

  9. Site investigations for repositories for solid radioactive wastes in shallow ground

    International Nuclear Information System (INIS)

    1982-01-01

    This report provides an overview and technical guidelines for investigations on a national level for the selection and confirmation of a repository site that will provide adequately safe performance for disposal of solid radioactive wastes that are low- or intermediate-level and short-lived. It also provides basic information on technical activities to be undertaken and on techniques that are available for such investigations in the various steps in selecting suitable sites. The report supplements the information given in Shallow Ground Disposal of Radioactive Wastes: A Guidebook, IAEA Safety Series No. 53 (1981). This report focuses mainly on different aspects of earth sciences and the various investigative techniques relative to earth sciences that may be necessary for site investigations. Some major related studies in other fields are discussed briefly. It is assumed that no previous investigations have been undertaken, and the report proceeds through area site selection to the stage when the site is confirmed as suitable for a waste repository

  10. Site investigations for repositories for solid radioactive wastes in shallow ground

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This report provides an overview and technical guidelines for investigations on a national level for the selection and confirmation of a repository site that will provide adequately safe performance for disposal of solid radioactive wastes that are low- or intermediate-level and short-lived. It also provides basic information on technical activities to be undertaken and on techniques that are available for such investigations in the various steps in selecting suitable sites. The report supplements the information given in Shallow Ground Disposal of Radioactive Wastes: A Guidebook, IAEA Safety Series No. 53 (1981). This report focuses mainly on different aspects of earth sciences and the various investigative techniques relative to earth sciences that may be necessary for site investigations. Some major related studies in other fields are discussed briefly. It is assumed that no previous investigations have been undertaken, and the report proceeds through area site selection to the stage when the site is confirmed as suitable for a waste repository.

  11. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, Robert P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2009 of the performance of a repository for spent nuclear fuel and high - level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment - specific laboratory experiments, in - situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site - specific characterization . The current sixth period beyond 2010 represents a new effort to set waste management policy in the United States. Because the relationship is important to understanding the evolution of the Yucca Mountain Project , the tabulation also shows the interaction between the policy realm and technical realm using four broad categories of events : (a) Regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives, (c) technical milestones of implementing institutions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste. Preface The historical progression of technical milestones for the Yucca Mountain Project was originally developed for 10 journal articles in a special issue of Reliability Engineering System Safety on the performance assessment for the Yucca Mountain license

  12. Near Field sorption Data Bases for Compacted MX-80 Bentonite for Performance Assessment of a High-Level Radioactive Waste Repository in Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.; Baeyens, B

    2003-08-01

    Bentonites of various types and compacted forms are being investigated in many countries as backfill materials in high-level radioactive waste disposal concepts. Nagra is currently considering an Opalinus clay (OPA) formation in the Zuercher Weinland as a potential location for a high-level radioactive waste repository. A compacted MX-80 bentonite is foreseen as a potential backfill material. Performance assessment studies will be performed for this site and one of the requirements for such an assessment are sorption data bases (SDB) for the bentonite near-field. The purpose of this report is to describe the procedures used to develop the SDB. One of the pre-requisites for developing a SDB is a water chemistry for the compacted bentonite porewater. For a number of reasons mentioned in the report, and discussed in more detail elsewhere, this is not a straightforward task. There are considerable uncertainties associated with the major ion concentrations and in particular with the system pH and Eh. The MX-80 SDB was developed for a reference bentonite porewater (pH = 7.25) which was calculated using the reference OPA porewater. In addition, two further SDBs are presented for porewaters calculated at pH values of 6.9 and 7.9 corresponding to lower and upper bound values calculated for the range of groundwater compositions anticipated for the OPA host rock. 'In house' sorption isotherm data were measured for Cs(I), Ni(II), Eu(III), Th(IV), Se(IV) and 1(-1) on the 'as received' MX-80 material equilibrated with a simulated porewater composition. Complementary 'in house' sorption edge and isotherm measurements on conditioned Na/Ca montmorillonites were also available for many of these radionuclides. These data formed the core of the SDB. Nevertheless, some of the required sorption data still had to be obtained from the open literature. An important part of this report is concerned with describing selection procedures and the modifications

  13. Process model repositories and PNML

    NARCIS (Netherlands)

    Hee, van K.M.; Post, R.D.J.; Somers, L.J.A.M.; Werf, van der J.M.E.M.; Kindler, E.

    2004-01-01

    Bringing system and process models together in repositories facilitates the interchange of model information between modelling tools, and allows the combination and interlinking of complementary models. Petriweb is a web application for managing such repositories. It supports hierarchical process

  14. Low level waste repositories

    International Nuclear Information System (INIS)

    Hill, P.R.H.; Wilson, M.A.

    1983-11-01

    Factors in selecting a site for low-level radioactive waste disposal are discussed. South Australia has used a former tailings dam in a remote, arid location as a llw repository. There are also low-level waste disposal procedures at the Olympic Dam copper/uranium project

  15. CRIS and Institutional Repositories

    Directory of Open Access Journals (Sweden)

    A Asserson

    2010-04-01

    Full Text Available CRIS (Current Research Information Systems provide researchers, research managers, innovators, and others with a view over the research activity of a domain. IRs (institutional repositories provide a mechanism for an organisation to showcase through OA (open access its intellectual property. Increasingly, organizations are mandating that their employed researchers deposit peer-reviewed published material in the IR. Research funders are increasingly mandating that publications be deposited in an open access repository: some mandate a central (or subject-based repository, some an IR. In parallel, publishers are offering OA but replacing subscription-based access with author (or author institution payment for publishing. However, many OA repositories have metadata based on DC (Dublin Core which is inadequate; a CERIF (Common-European Research Information Format CRIS provides metadata describing publications with formal syntax and declared semantics thus facilitating interoperation or homogeneous access over heterogeneous sources. The formality is essential for research output metrics, which are increasingly being used to determine future funding for research organizations.

  16. Salt repository design approach

    International Nuclear Information System (INIS)

    Matthews, S.C.

    1983-01-01

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure

  17. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the third part of a report of a preliminary study for AECL. It summarizes the topics considered in reports AECL-6188-1 and AECL-6188-2 as requirements for an undergpound repository for disposal of wastes produced by the Canadian Nuclear Fuel Program. (author)

  18. Computational Materials Repository

    DEFF Research Database (Denmark)

    Landis, David

    , different abstraction levels and enables users to analyze their own results, and allows to share data with collaborators. The approach of the Computational Materials Repository (CMR) is to convert data to an internal format that maintains the original variable names without insisting on any semantics...

  19. The Computational Materials Repository

    DEFF Research Database (Denmark)

    Landis, David D.; Hummelshøj, Jens S.; Nestorov, Svetlozar

    2012-01-01

    The possibilities for designing new materials based on quantum physics calculations are rapidly growing, but these design efforts lead to a significant increase in the amount of computational data created. The Computational Materials Repository (CMR) addresses this data challenge and provides...

  20. Consortial routes to effective repositories

    OpenAIRE

    Moyle, M.; Proudfoot, R.

    2009-01-01

    A consortial approach to the establishment of repository services can help a group of Higher Education Institutions (HEIs) to share costs, share technology and share expertise. Consortial repository work can tap into existing structures, or it can involve new groupings of institutions with a common interest in exploring repository development. This Briefing Paper outlines some of the potential benefits of collaborative repository activity, and highlights some of the technical and organisation...

  1. Gabbro as a host rock for a nuclear waste repository

    International Nuclear Information System (INIS)

    Ahlbom, K.; Leijon, B.; Smellie, J.; Liedholm, M.

    1992-09-01

    As an alternative to granitic rocks, gabbro and other basic rock types have been investigated with respect to their suitability to host a nuclear waste repository. The present report summarizes and examines existing geoscientific knowledge of relevance in assessing the potential merits of gabbro as a repository host rock. Implications in terms of site selection, repository construction and post-closure repository performance are also discussed. The objective of the study is to provide a basis for decisions as regards future consideration of the gabbro alternative. It is found that there are rather few gabbro bodies in Sweden, that are potentially of sufficient size to host a repository. Thus, gabbro offers little latitude as regards site selection. In comparison to siting a repository in granitic rocks, this is a major disadvantage, and it may in fact remove gabbro from further consideration. The potential advantages of gabbro refer to repository performance, and include low hydraulic conductivity and a chemical environment promoting efficient radionuclide retardation. However, results from field investigations show that groundwater flow in gabbro bodies is largely controlled by intersecting heterogeneities, in particular granitic dykes, that are significantly more conductive to water than the gabbro. In the far-field scale significant to repository performance, this may reduce or eliminate the potential effects of favourable hydraulic and chemical characteristics of the gabbro itself. In conclusion, there are apparent difficulties associated with siting a repository in gabbro, due to lack of sufficiently large gabbro bodies. On the basis of the present state of knowledge, no decisive differences can be demonstrated when comparing gabbro with granitic rocks, neither with respects to repository construction, nor as regards repository performance. (au)

  2. Plutonian Moon confirmed

    Science.gov (United States)

    In late February, two separate observations confirmed the 1978 discovery by U.S. Naval Observatory scientist James W. Christy of a moon orbiting the planet Pluto. According to the U.S. Naval Observatory, these two observations were needed before the International Astronomical Society (IAS) would officially recognize the discovery.Two types of observations of the moon, which was named Charon after the ferryman in Greek mythology who carried the dead to Pluto's realm, were needed for confirmation: a transit, in which the moon passes in front of Pluto, and an occultation, in which the moon passes behind the planet. These two phenomena occur only during an 8-year period every 124 years that had been calculated to take place during 1984-1985. Both events were observed in late February.

  3. Knowledge repositories for multiple uses

    Science.gov (United States)

    Williamson, Keith; Riddle, Patricia

    1991-01-01

    In the life cycle of a complex physical device or part, for example, the docking bay door of the Space Station, there are many uses for knowledge about the device or part. The same piece of knowledge might serve several uses. Given the quantity and complexity of the knowledge that must be stored, it is critical to maintain the knowledge in one repository, in one form. At the same time, because of quantity and complexity of knowledge that must be used in life cycle applications such as cost estimation, re-design, and diagnosis, it is critical to automate such knowledge uses. For each specific use, a knowledge base must be available and must be in a from that promotes the efficient performance of that knowledge base. However, without a single source knowledge repository, the cost of maintaining consistent knowledge between multiple knowledge bases increases dramatically; as facts and descriptions change, they must be updated in each individual knowledge base. A use-neutral representation of a hydraulic system for the F-111 aircraft was developed. The ability to derive portions of four different knowledge bases is demonstrated from this use-neutral representation: one knowledge base is for re-design of the device using a model-based reasoning problem solver; two knowledge bases, at different levels of abstraction, are for diagnosis using a model-based reasoning solver; and one knowledge base is for diagnosis using an associational reasoning problem solver. It was shown how updates issued against the single source use-neutral knowledge repository can be propagated to the underlying knowledge bases.

  4. Consequences of the Thermal Transient on the Evolution of the Damaged Zone Around a Repository for Heat-Emitting High-Level Radioactive Waste in a Clay Formation: a Performance Assessment Perspective

    Science.gov (United States)

    Yu, Li; Weetjens, Eef; Sillen, Xavier; Vietor, Tim; Li, Xiangling; Delage, Pierre; Labiouse, Vincent; Charlier, Robert

    2014-01-01

    A proper evaluation of the perturbations of the host rock induced by the excavation and the emplacement of exothermic wastes is essential for the assessment of the long-term safety of high-level radioactive waste disposals in clay formations. The impact of the thermal transient on the evolution of the damaged zone (DZ) has been explored in the European Commission project TIMODAZ (thermal impact on the damaged zone around a radioactive waste disposal in clay host rocks, 2006-2010). This paper integrates the scientific results of the TIMODAZ project from a performance assessment (PA) point of view, showing how these results support and justify key PA assumptions and the values of PA model parameters. This paper also contextualises the significance of the thermal impact on the DZ from a safety case perspective, highlighting how the project outcomes result into an improved understanding of the thermo-hydro-mechanical behaviour of the clay host rocks. The results obtained in the TIMODAZ project strengthen the assessment basis of the safety evaluation of the current repository designs. There was no evidence throughout the TIMODAZ experimental observations of a temperature-induced additional opening of fractures nor of a significant permeability increase of the DZ. Instead, thermally induced plasticity, swelling and creep seem to be beneficial to the sealing of fractures and to the recovery of a very low permeability in the DZ, close to that of an undisturbed clay host rock. Results from the TIMODAZ project indicate that the favourable properties of the clay host rock, which guarantee the effectiveness of the safety functions of the repository system, are expected to be maintained after the heating-cooling cycle. Hence, the basic assumptions usually made in PA calculations so far are expected to remain valid, and the performance of the system should not be affected in a negative way by the thermal evolution of the DZ around a radioactive waste repository in clay host rock.

  5. Proposed methodology for completion of scenario analysis for the Basalt Waste Isolation Project. [Assessment of post-closure performance for a proposed repository for high-level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Roberds, W.J.; Plum, R.J.; Visca, P.J.

    1984-11-01

    This report presents the methodology to complete an assessment of postclosure performance, considering all credible scenarios, including the nominal case, for a proposed repository for high-level nuclear waste at the Hanford Site, Washington State. The methodology consists of defensible techniques for identifying and screening scenarios, and for then assessing the risks associated with each. The results of the scenario analysis are used to comprehensively determine system performance and/or risk for evaluation of compliance with postclosure performance criteria (10 CFR 60 and 40 CFR 191). In addition to describing the proposed methodology, this report reviews available methodologies for scenario analysis, discusses pertinent performance assessment and uncertainty concepts, advises how to implement the methodology (including the organizational requirements and a description of tasks) and recommends how to use the methodology in guiding future site characterization, analysis, and engineered subsystem design work. 36 refs., 24 figs., 1 tab.

  6. Publishers and repositories

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The impact of self-archiving on journals and publishers is an important topic for all those involved in scholarly communication. There is some evidence that the physics arXiv has had no impact on physics journals, while 'economic common sense' suggests that some impact is inevitable. I shall review recent studies of librarian attitudes towards repositories and journals, and place this in the context of IOP Publishing's experiences with arXiv. I shall offer some possible reasons for the mis-match between these perspectives and then discuss how IOP has linked with arXiv and experimented with OA publishing. As well as launching OA journals we have co-operated with Cornell and the arXiv on Eprintweb.org, a platform that offers new features to repository users. View Andrew Wray's biography

  7. Distributed Web Service Repository

    Directory of Open Access Journals (Sweden)

    Piotr Nawrocki

    2015-01-01

    Full Text Available The increasing availability and popularity of computer systems has resulted in a demand for new, language- and platform-independent ways of data exchange. That demand has in turn led to a significant growth in the importance of systems based on Web services. Alongside the growing number of systems accessible via Web services came the need for specialized data repositories that could offer effective means of searching of available services. The development of mobile systems and wireless data transmission technologies has allowed the use of distributed devices and computer systems on a greater scale. The accelerating growth of distributed systems might be a good reason to consider the development of distributed Web service repositories with built-in mechanisms for data migration and synchronization.

  8. Shared Medical Imaging Repositories.

    Science.gov (United States)

    Lebre, Rui; Bastião, Luís; Costa, Carlos

    2018-01-01

    This article describes the implementation of a solution for the integration of ownership concept and access control over medical imaging resources, making possible the centralization of multiple instances of repositories. The proposed architecture allows the association of permissions to repository resources and delegation of rights to third entities. It includes a programmatic interface for management of proposed services, made available through web services, with the ability to create, read, update and remove all components resulting from the architecture. The resulting work is a role-based access control mechanism that was integrated with Dicoogle Open-Source Project. The solution has several application scenarios like, for instance, collaborative platforms for research and tele-radiology services deployed at Cloud.

  9. Czech Republic. Dukovany repository

    International Nuclear Information System (INIS)

    2001-01-01

    Full text: The repository at the Dukovany site is a structure located above the land surface. It consists of two double-rows of reinforced concrete vaults. Each double-row has dimensions 38x160x6 meters and contains 2x28 vaults. The internal dimensions of each vault are 18x6x5.4 meters. The repository serves for reactor wastes from the Dukovany and Temelin nuclear power plants (NPPs). Its capacity is 55,000 m 3 or 130,000 drums. The repository is a fully engineered facility with multiple barriers. The first engineered barrier is the waste form (in the case of waste from the Dukovany NPP, the waste form is mainly bitumen, but concrete and glass are also considered as suitable solidification products). The second barrier is the container (a 200 litre steel drum or a HIC container), whereas the third consists of cut-off reinforced concrete walls with asphalt-based hydro-insulation. The fourth barrier is a cap which should protect the vaults against infiltration of rainwater and should serve also as an intrusion and erosion barrier. The fifth barrier is a drainage system around the repository which is composed of layers of gravel and sand. The void space in drums around the waste is filled with specially composed grout. Such waste packages are emplaced into the disposal vault, which is covered by pre-fabricated panels. Thereafter, joints between the panels are sealed and a provisional coverage added; the final cover, however, will be constructed only over the whole row of 28 vaults, until all vaults are filled with waste. The final cover will encompass the following components: reinforced concrete pre-fabricated panels (500 mm); cement overcoat (30 mm); insulation foil; concrete layer for cap levelling (5-150 mm); layer of asphalto-propylene concrete (150 mm); soil (450 mm); geotextile foil with topsoil (top surface vegetation). (author)

  10. Isotopic Generation and Confirmation of the PWR Application Model?

    International Nuclear Information System (INIS)

    L.B. Wimmer

    2003-01-01

    The objective of this calculation is to establish an isotopic database to represent commercial spent nuclear fuel (CSNF) from pressurized water reactors (PWRs) in criticality analyses performed for the proposed Monitored Geologic Repository at Yucca Mountain, Nevada. Confirmation of the conservatism with respect to criticality in the isotopic concentration values represented by this isotopic database is performed as described in Section 3.5.3.1.2 of the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2000). The isotopic database consists of the set of 14 actinides and 15 fission products presented in Section 3.5.2.1.1 of YMP 2000 for use in CSNF burnup credit. This set of 29 isotopes is referred to as the principal isotopes. The oxygen isotope from the UO 2 fuel is also included in the database. The isotopic database covers enrichments of 235 U ranging from 1.5 to 5.5 weight percent (wt%) and burnups ranging from approximately zero to 75 GWd per metric ton of uranium (mtU). The choice of fuel assembly and operating history values used in generating the isotopic database are provided is Section 5. Tables of isotopic concentrations for the 29 principal isotopes (plus oxygen) as a function of enrichment and burnup are provided in Section 6.1. Results of the confirmation of the conservatism with respect to criticality in the isotopic concentration values are provided in Section 6.2

  11. Geoengineering properties of potential repository units at Yucca Mountain, southern Nevada

    International Nuclear Information System (INIS)

    Tillerson, J.R.; Nimick, F.B.

    1984-12-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) Project is currently evaluating volcanic tuffs at the Yucca Mountain site, located on and adjacent to the Nevada Test Site, for possible use as a host rock for a radioactive waste repository. The behavior of tuff as an engineering material must be understood to design, license, construct, and operate a repository. Geoengineering evaluations and measurements are being made to develop confidence in both the analysis techniques for thermal, mechanical, and hydrothermal effects and the supporting data base of rock properties. The analysis techniques and the data base are currently used for repository design, waste package design, and performance assessment analyses. This report documents the data base of geoengineering properties used in the analyses that aided the selection of the waste emplacement horizon and in analyses synopsized in the Environmental Assessment Report prepared for the Yucca Mountain site. The strategy used for the development of the data base relies primarily on data obtained in laboratory tests that are then confirmed in field tests. Average thermal and mechanical properties (and their anticipated variations) are presented. Based upon these data, analyses completed to date, and previous excavation experience in tuff, it is anticipated that existing mining technology can be used to develop stable underground openings and that repository operations can be carried out safely

  12. Research Opportunities in Corrosion Science for Long-Term Prediction of Materials Performance: A Report of the DOE Workshop on ''Corrosion Issues of Relevance to the Yucca Mountain Waste Repository''

    International Nuclear Information System (INIS)

    Payer, Joe H.; Scully, John R.

    2003-01-01

    The report summarizes the findings of a U.S. Department of Energy workshop on ''Corrosion Issues of Relevance to the Yucca Mountain Waste Repository''. The workshop was held on July 29-30, 2003 in Bethesda, MD, and was co-sponsored by the Office of Basic Energy Sciences and Office of Civilian Radioactive Waste Management. The workshop focus was corrosion science relevant to long-term prediction of materials performance in hostile environments, with special focus on relevance to the permanent disposal of nuclear waste at the Yucca Mountain Repository. The culmination of the workshop is this report that identifies both generic and Yucca Mountain Project-specific research opportunities in basic and applied topic areas. The research opportunities would be realized well after the U.S. Nuclear Regulatory Commission's initial construction-authorization licensing process. At the workshop, twenty-three invited scientists deliberated on basic and applied science opportunities in corrosion science relevant to long-term prediction of damage accumulation by corrosive processes that affect materials performance.

  13. Impact of production and release of gas in a L/ILW repository. A summary of the work performed within the Nagra programme

    International Nuclear Information System (INIS)

    Zuidema, P.; Hoglund, L.O.

    1988-01-01

    In a repository for low- and intermediate-level radioactive wastes, gases will be formed due to corrosion of metals, microbial degradation of organic materials and radiolytic decomposition of water and organic materials. The predominant source of gas is calculated to be anaerobic corrosion of metals, particularly iron. Gas pressure will build up in the near-field until it is released through the system of engineered barriers into the geosphere at a rate equivalent to the production rate. Excessive gas pressures may damage the engineered barriers if no precautions are taken. Radionuclide transport both through the host rock and near-field may be influenced by such gas releases. Water will be displaced and local hydrology will be altered. The significance of these alterations are site-specific; theoretical studies as well as field investigations are underway to clarify the role of the different processes involved

  14. PASS - Project on Alternative Systems Study. Performance assessment of bentonite clay barrier in three repository concepts: VDH, KBS-3 and VLH

    International Nuclear Information System (INIS)

    Pusch, R.; Boergesson, L.

    1992-12-01

    The three repository concepts VDH, KBS3 and VLH have been investigated with respect to their functions in short- and long-term perspectives. The study shows that while KBS3 does not require development of new techniques for excavation and application of buffers and canisters, such development is needed for VLH and VDH. The various physical processes in the deployment part of VDH are more critical and less understood than those in KBS3 and VLH, but the sealing effect of the plugged 'low-temperature' part is sufficiently good to make the concept qualify as a candidate. VLH has the highest and KBS3 the lowest temperature and the latter has the highest potential for good long-term function. (59 refs.)

  15. Guidelines for the operation and closure of deep geological repositories for the disposal of high level and alpha bearing wastes

    International Nuclear Information System (INIS)

    1991-10-01

    The operation and closure of a deep geological repository for the disposal of high level and alpha bearing wastes is a long term project involving many disciplines. This unique combination of nuclear operations in a deep underground location will require careful planning by the operating organization. The basic purpose of the operation stage of the deep repository is to ensure the safe disposal of the radioactive wastes. The purpose of the closure stage is to ensure that the wastes are safely isolated from the biosphere, and that the surface region can be returned to normal use. During these two stages of operation and closure, it is essential that both workers and the public are safely protected from radiation hazards, and that workers are protected from the hazards of working underground. For these periods of the repository, it is essential to carry out monitoring for purposes of radiological protection, and to continue testing and investigations to provide data for repository performance confirmation and for final safety assessment. Over the lengthy stages of operation and closure, there will be substantial feedback of experience and generation of site data. These will lead both to improved quality of operation and a better understanding of the site characteristics, thereby enhancing the confidence in the ability of the repository system to isolate the waste and protect future generations. 15 refs

  16. Towards Interoperable Preservation Repositories: TIPR

    Directory of Open Access Journals (Sweden)

    Priscilla Caplan

    2010-07-01

    Full Text Available Towards Interoperable Preservation Repositories (TIPR is a project funded by the Institute of Museum and Library Services to create and test a Repository eXchange Package (RXP. The package will make it possible to transfer complex digital objects between dissimilar preservation repositories.  For reasons of redundancy, succession planning and software migration, repositories must be able to exchange copies of archival information packages with each other. Every different repository application, however, describes and structures its archival packages differently. Therefore each system produces dissemination packages that are rarely understandable or usable as submission packages by other repositories. The RXP is an answer to that mismatch. Other solutions for transferring packages between repositories focus either on transfers between repositories of the same type, such as DSpace-to-DSpace transfers, or on processes that rely on central translation services.  Rather than build translators between many dissimilar repository types, the TIPR project has defined a standards-based package of metadata files that can act as an intermediary information package, the RXP, a lingua franca all repositories can read and write.

  17. Upgrading of radon's type near surface repository in Latvia

    International Nuclear Information System (INIS)

    Abramenkovs, A.

    2006-01-01

    In 1959, the Soviet government decided to construct the near surface radioactive wastes repository 'Radons' near the Baldone city. It was put in operation in 1962. The changes in the development of the repository were induced by the necessarily to upgrade it for disposal of radioactive wastes from the decommissioning of the Salaspils Research Reactor (SRR). The safety assessment of repository was performed during 2000-2001 under the PHARE project for necessary upgrades of repository. The outline design for new vaults and interim storage for long lived radioactive wastes was elaborated during 2003-2004 years. The Environmental Impact Assessment (EIA) for upgrade of Baldone repository was performed during 2004-2005 years. It was found, that additional efforts must be devoted for solution of social aspects o for successful operation and upgrade of repository. It was shown by EIA, that the local population has a negative opinion against the upgrade of repository in Latvia. The main recommendations for upgrades were connected with increasing the safety of repository, increasing of PR activities for education of society and developing of compensation mechanism for local municipality. (author)

  18. A Summary of Properties Used to Evaluate INEEL Calcine Disposal in the Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Dahl, C.A.

    2003-01-01

    To support evaluations of the direct disposal of Idaho National Engineering and Environmental Laboratory calcines to the repository at Yucca Mountain, an evaluation of the performance of the calcine in the repository environment must be performed. This type of evaluation demonstrates, through computer modeling and analysis, the impact the calcine would have on the ability of the repository to perform its function of containment of materials during the repository lifetime. This report discusses parameters that were used in the scoping evaluation conducted in FY 2003. It provides nominal values for the parameters, with explanation of the source of the values, and how the values were modified for use in repository analysis activities

  19. CONFIRMATION OF CIRCUMSTELLAR PHOSPHINE

    Energy Technology Data Exchange (ETDEWEB)

    Agúndez, M.; Cernicharo, J. [Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, E-28049 Cantoblanco (Spain); Decin, L. [Sterrenkundig Instituut Anton Pannekoek, University of Amsterdam, Science Park 904, NL-1098 Amsterdam (Netherlands); Encrenaz, P. [LERMA, Observatoire de Paris, 61 Av. de l' Observatoire, F-75014 Paris (France); Teyssier, D. [European Space Astronomy Centre, Urb. Villafranca del Castillo, P.O. Box 50727, E-28080 Madrid (Spain)

    2014-08-01

    Phosphine (PH{sub 3}) was tentatively identified a few years ago in the carbon star envelopes IRC +10216 and CRL 2688 from observations of an emission line at 266.9 GHz attributable to the J = 1-0 rotational transition. We report the detection of the J = 2-1 rotational transition of PH{sub 3} in IRC +10216 using the HIFI instrument on board Herschel, which definitively confirms the identification of PH{sub 3}. Radiative transfer calculations indicate that infrared pumping in excited vibrational states plays an important role in the excitation of PH{sub 3} in the envelope of IRC +10216, and that the observed lines are consistent with phosphine being formed anywhere between the star and 100 R {sub *} from the star, with an abundance of 10{sup –8} relative to H{sub 2}. The detection of PH{sub 3} challenges chemical models, none of which offer a satisfactory formation scenario. Although PH{sub 3} holds just 2% of the total available phosphorus in IRC +10216, it is, together with HCP, one of the major gas phase carriers of phosphorus in the inner circumstellar layers, suggesting that it could also be an important phosphorus species in other astronomical environments. This is the first unambiguous detection of PH{sub 3} outside the solar system, and is a further step toward a better understanding of the chemistry of phosphorus in space.

  20. Thermal analyses of KBS-3H type repository

    International Nuclear Information System (INIS)

    Ikonen, K.

    2003-12-01

    This report contains the temperature dimensioning of the KBS-3H type nuclear fuel repository, where the fuel canisters are disposed at horizontal position in the horizontal tunnels according to the preliminary SKB (Swedish Nuclear Fuel and Waste Management Co) and Posiva plan. The maximum temperature on the canister surface is limited to the design temperature of +100 deg C. However, due to uncertainties in thermal analysis parameters (like scattering in rock conductivity) the allowable calculated maximum canister temperature is set to 90 deg C causing a safety margin of 10 deg C. The allowable temperature is controlled by adjusting the space between adjacent canisters, adjacent tunnels and the distance between separate panels of the repository and the pre-cooling time affecting power of the canisters. With reasonable canister and tunnel spacing the maximum temperature 90 deg C is achieved with an initial canister power of 1700 W. It became apparent that the temperature of canister surfaces can be determined by superposing analytic line heat source models much more efficiently than by numerical analysis, if the analytic model is first verified and calibrated by numerical analysis. This was done by comparing the surface temperatures of the central canister in a single infinite canister queue calculated numerically and analytically. In addition, the results from SKB analysis were used for comparison and for confirming the calculation procedure. For the Olkiluoto repository a reference case of one panel having 1500 canisters was analysed. The canisters are disposed in a rectangular geometry in a certain order. The calculation was performed separately for both Olkiluoto BWR canisters and Loviisa PWR canisters. The result was the minimum allowable spacing between canisters. (orig.)

  1. NASA Biological Specimen Repository

    Science.gov (United States)

    McMonigal, K. A.; Pietrzyk, R. A.; Sams, C. F.; Johnson, M. A.

    2010-01-01

    The NASA Biological Specimen Repository (NBSR) was established in 2006 to collect, process, preserve and distribute spaceflight-related biological specimens from long duration ISS astronauts. This repository provides unique opportunities to study longitudinal changes in human physiology spanning may missions. The NBSR collects blood and urine samples from all participating ISS crewmembers who have provided informed consent. These biological samples are collected once before flight, during flight scheduled on flight days 15, 30, 60, 120 and within 2 weeks of landing. Postflight sessions are conducted 3 and 30 days after landing. The number of in-flight sessions is dependent on the duration of the mission. Specimens are maintained under optimal storage conditions in a manner that will maximize their integrity and viability for future research The repository operates under the authority of the NASA/JSC Committee for the Protection of Human Subjects to support scientific discovery that contributes to our fundamental knowledge in the area of human physiological changes and adaptation to a microgravity environment. The NBSR will institute guidelines for the solicitation, review and sample distribution process through establishment of the NBSR Advisory Board. The Advisory Board will be composed of representatives of all participating space agencies to evaluate each request from investigators for use of the samples. This process will be consistent with ethical principles, protection of crewmember confidentiality, prevailing laws and regulations, intellectual property policies, and consent form language. Operations supporting the NBSR are scheduled to continue until the end of U.S. presence on the ISS. Sample distribution is proposed to begin with selections on investigations beginning in 2017. The availability of the NBSR will contribute to the body of knowledge about the diverse factors of spaceflight on human physiology.

  2. The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis.

    Science.gov (United States)

    Li, S; Tang, X; Peng, L; Luo, Y; Dong, R; Liu, J

    2015-05-01

    To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFRCT) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFRCT, with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) for FFRCT were 89% (85-93%), 71% (65-75%), 70% (65-75%), 90% (85-93%), 3.31 (1.79-6.14), 0.16 (0.11-0.23), and 21.21 (9.15-49.15) at the patient-level, and 83% (78-63%), 78% (75-81%), 61% (56-65%), 92% (89-90%), 4.02 (1.84-8.80), 0.22 (0.13-0.35), and 19.15 (5.73-63.93) at the vessel-level. At per-patient analysis, FFRCT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR-, and DOR versus those of CTA. At per-vessel analysis, FFRCT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR-, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFRCT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. FFRCT, which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  3. The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis

    International Nuclear Information System (INIS)

    Li, S.; Tang, X.; Peng, L.; Luo, Y.; Dong, R.; Liu, J.

    2015-01-01

    Aim: To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFR CT ) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. Materials and methods: A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFR CT , with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Results: Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR) for FFR CT were 89% (85–93%), 71% (65–75%), 70% (65–75%), 90% (85–93%), 3.31 (1.79–6.14), 0.16 (0.11–0.23), and 21.21 (9.15–49.15) at the patient-level, and 83% (78–63%), 78% (75–81%), 61% (56–65%), 92% (89–90%), 4.02 (1.84–8.80), 0.22 (0.13–0.35), and 19.15 (5.73–63.93) at the vessel-level. At per-patient analysis, FFR CT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR−, and DOR versus those of CTA. At per-vessel analysis, FFR CT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR−, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFR CT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. Conclusions: FFR CT , which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions

  4. Space Telecommunications Radio System (STRS) Application Repository Design and Analysis

    Science.gov (United States)

    Handler, Louis M.

    2013-01-01

    The Space Telecommunications Radio System (STRS) Application Repository Design and Analysis document describes the STRS application repository for software-defined radio (SDR) applications intended to be compliant to the STRS Architecture Standard. The document provides information about the submission of artifacts to the STRS application repository, to provide information to the potential users of that information, and for the systems engineer to understand the requirements, concepts, and approach to the STRS application repository. The STRS application repository is intended to capture knowledge, documents, and other artifacts for each waveform application or other application outside of its project so that when the project ends, the knowledge is retained. The document describes the transmission of technology from mission to mission capturing lessons learned that are used for continuous improvement across projects and supporting NASA Procedural Requirements (NPRs) for performing software engineering projects and NASAs release process.

  5. INSTITUTIONAL REPOSITORY: EMPLOYMENT IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Vasyl P. Oleksyuk

    2012-11-01

    Full Text Available The article investigated the concept of «institutional repository» and determined the aspects of institutional repositories in higher education. Institutional Repositories are information systems that allow preserving, storing and disseminating scientific knowledge produced in higher education and scientific research institutions. This study presented the main aspects using institutional repositories in educational process (such as storage of scientific and educational information, means of organization activity of students, object of studying. This article produced the structure of communities and collections of the institutional. It is described the experience of implementing of DSpace in the learning process.

  6. Future extension of the Swedish repository for low and intermediate level waste (SFR)

    International Nuclear Information System (INIS)

    Carlsson, Jan

    2006-01-01

    The existing Swedish repository for low and intermediate level waste (SFR) is licensed for disposal of short-lived waste originated from operation and maintenance of Swedish nuclear power plants. The repository is foreseen to be extended to accommodate short-lived waste from the future decommissioning of the Nuclear Power Plants. Long-lived waste from operation, maintenance and eventually decommissioning will be stored some years before disposal in a geological repository. This repository can be build either as a further extension of the SFR facility or as a separate repository. This paper discusses the strategy of a step-wise extended repository where the extensions are performed during operation of the existing parts of the repository. It describes the process for licensing new parts of the repository (and re-license of the existing parts). (author)

  7. Integrated safety case development for deep geological repositories

    International Nuclear Information System (INIS)

    Kawamura, Hideki; McKinley, Ian G.

    2008-01-01

    The paper will illustrate an 'integrated safety case', which involves combining both pre-closure and post-closure safety arguments from the point of view of a repository implementer, who must also ensure that projects are practical, acceptable and economic. The post-closure safety case is based on the performance of a number of barriers, which are established during construction, operation and closure. Such barriers must be confirmed using quality assured methods, supported, as required, by inspection and monitoring. The requirement for integrated assessment means that even the final process to end institutional control and transfer any liabilities from the implementer needs to be considered at present, even though this will undoubtedly be refined and tailored to the site characteristics over the many decades that will pass before this occurs. To illustrate the practical application of this approach, assessment of variants for remote-handled emplacement of the EBS for disposal of HLW in Japan will be discussed. (author)

  8. Fundamentals of the NEA Thermochemical Database and its influence over national nuclear programs on the performance assessment of deep geological repositories.

    Science.gov (United States)

    Ragoussi, Maria-Eleni; Costa, Davide

    2017-03-14

    For the last 30 years, the NEA Thermochemical Database (TDB) Project (www.oecd-nea.org/dbtdb/) has been developing a chemical thermodynamic database for elements relevant to the safety of radioactive waste repositories, providing data that are vital to support the geochemical modeling of such systems. The recommended data are selected on the basis of strict review procedures and are characterized by their consistency. The results of these efforts are freely available, and have become an international point of reference in the field. As a result, a number of important national initiatives with regard to waste management programs have used the NEA TDB as their basis, both in terms of recommended data and guidelines. In this article we describe the fundamentals and achievements of the project together with the characteristics of some databases developed in national nuclear waste disposal programs that have been influenced by the NEA TDB. We also give some insights on how this work could be seen as an approach to be used in broader areas of environmental interest. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son (ed.) [Canadian Nuclear Safety Commission (Canada); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Chijimatzu, Masakazu [Hazama Corporation (Japan); Jussila, Petri [Helsinki Univ. of Technology, Helsinki (Finland); Rutqvist, Jonny [Lawrence Berkeley National Laboratory CA (United States)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the

  10. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    International Nuclear Information System (INIS)

    Nguyen, Son; Lanru Jing; Boergesson, Lennart; Chijimatzu, Masakazu; Jussila, Petri; Rutqvist, Jonny

    2007-02-01

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the container

  11. Object linking in repositories

    Science.gov (United States)

    Eichmann, David (Editor); Beck, Jon; Atkins, John; Bailey, Bill

    1992-01-01

    This topic is covered in three sections. The first section explores some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life cycle of software development. A model is considered that provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The second section gives a description of the efforts to implement the repository architecture using a commercially available object-oriented database management system. Some of the features of this implementation are described, and some of the next steps to be taken to produce a working prototype of the repository are pointed out. In the final section, it is argued that design and instantiation of reusable components have competing criteria (design-for-reuse strives for generality, design-with-reuse strives for specificity) and that providing mechanisms for each can be complementary rather than antagonistic. In particular, it is demonstrated how program slicing techniques can be applied to customization of reusable components.

  12. Assessment of Public Acceptability in LILW Repository Site Selection Process in Slovenia

    International Nuclear Information System (INIS)

    Zeleznik, N.; Kralj, M.; Polic, M.; Kos, D.

    2006-01-01

    repository). For each of the applied local communities the research team has conducted analyses and research in their local environment. The results of the research have been than compared and further assessed in order to obtain 3 local communities in which perspective of positive public acceptance for the LILW repository seems to be the highest. It is planned that with selected candidate local communities local partnership will be established which will serve us an umbrella for all activities during site characterization and confirmation and will also be the platform for cooperation and for decision making of local stake holders. The paper will present the approach to the public acceptability assessment and the results of the research which have been performed for prefeasibility study. (author)

  13. Management strategy for site characterization at candidate HLW repository sites

    International Nuclear Information System (INIS)

    Bartlett, J.W.

    1988-01-01

    This paper describes a management strategy for HLW repository site characterization which is aimed at producing an optimal characterization trajectory for site suitability and licensing evaluations. The core feature of the strategy is a matrix of alternative performance targets and alternative information-level targets which can be used to allocate and justify program effort. Strategies for work concerning evaluation of expected and disrupted repository performance are distinguished, and the need for issue closure criteria is discussed

  14. Accelerator Physics Code Web Repository

    CERN Document Server

    Zimmermann, Frank; Bellodi, G; Benedetto, E; Dorda, U; Giovannozzi, Massimo; Papaphilippou, Y; Pieloni, T; Ruggiero, F; Rumolo, G; Schmidt, F; Todesco, E; Zotter, Bruno W; Payet, J; Bartolini, R; Farvacque, L; Sen, T; Chin, Y H; Ohmi, K; Oide, K; Furman, M; Qiang, J; Sabbi, G L; Seidl, P A; Vay, J L; Friedman, A; Grote, D P; Cousineau, S M; Danilov, V; Holmes, J A; Shishlo, A; Kim, E S; Cai, Y; Pivi, M; Kaltchev, D I; Abell, D T; Katsouleas, Thomas C; Boine-Frankenheim, O; Franchetti, G; Hofmann, I; Machida, S; Wei, J

    2006-01-01

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic acceleratorphysics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  15. Safety analysis in subsurface repositories

    International Nuclear Information System (INIS)

    1985-06-01

    The development of mathematical models to represent the repository-geosphere-biosphere system, and the development of a structure for data acquisition, processing, and use to analyse the safety of subsurface repositories, are presented. To study the behavior of radionuclides in geosphere a laboratory to determine the hydrodynamic dispersion coefficient was constructed. (M.C.K.) [pt

  16. Granite-repository - geochemical environment

    International Nuclear Information System (INIS)

    1979-04-01

    Some geochemical data of importance for a radioactive waste repository in hard rock are reviewed. The ground water composition at depth is assessed. The ground water chemistry in the vicinity of uranium ores is discussed. The redox system in Swedish bedrock is described. Influences of extreme climatic changes and of repository mining and construction are also evaluated

  17. ACCELERATION PHYSICS CODE WEB REPOSITORY.

    Energy Technology Data Exchange (ETDEWEB)

    WEI, J.

    2006-06-26

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  18. Cementitious near-field sorption data bases for performance assessment of a L/ILW repository in a Palfris marl host rock. CEM-94: update I, June 1997

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Loon, L.R. van

    1998-01-01

    This report is an update on an earlier cementitious sorption data base (SDB) prepared by Bradbury and Sarott (1994). The aim is to review any new information or data which have become available in the intervening time and modify the existing SDB appropriately. Discussions will be confined predominantly to areas which have led to significant changes to or reappraisals of the data/values or procedures for obtaining/modifying them. From this point of view this update and the previous SDB are closely related and belong together. The complexation of radionuclides with organic ligands from the chemical degradation of cellulose, and the subsequent negative effects on sorption properties, were identified as being processes of great importance. Since 1994 significant progress has been made in this field and a major part of this work is devoted to a reassessment of the impact of 'organics' on near-field sorption. In particular, the very conservative assumptions which had been made previously because of the general lack of good quality data available at that time, could be replaced by realistic parameter estimates based on new knowledge. For example, maximum likely concentrations of cellulose degradation products and cement additives in the cement pore waters could be calculated allowing the potential effects of these organic ligands on sorption to be bounded. Sorption values for safety relevant radionuclides corresponding to the three broad stages of cement/concrete degradation during the lifetime of the repository are presented in tabulated form. The influence of the wide variety of organic ligands existing in the different waste categories, SMA-1 to SMA-4, is quantified in terms of sorption reduction factors. In the compilation of this cement SDB update, radionuclide uptake onto the vast quantities of aggregate materials and corrosion products from iron/steel was not taken into account. (author) 10 figs., 8 tabs., refs

  19. Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

    International Nuclear Information System (INIS)

    Juncosa, R.; Delgado, J.; Font, I.

    2010-01-01

    Radioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion,..) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (i.e. phase) thereby affecting their reactive behavior. The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption). In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture. (orig.)

  20. Influence analysis of Github repositories.

    Science.gov (United States)

    Hu, Yan; Zhang, Jun; Bai, Xiaomei; Yu, Shuo; Yang, Zhuo

    2016-01-01

    With the support of cloud computing techniques, social coding platforms have changed the style of software development. Github is now the most popular social coding platform and project hosting service. Software developers of various levels keep entering Github, and use Github to save their public and private software projects. The large amounts of software developers and software repositories on Github are posing new challenges to the world of software engineering. This paper tries to tackle one of the important problems: analyzing the importance and influence of Github repositories. We proposed a HITS based influence analysis on graphs that represent the star relationship between Github users and repositories. A weighted version of HITS is applied to the overall star graph, and generates a different set of top influential repositories other than the results from standard version of HITS algorithm. We also conduct the influential analysis on per-month star graph, and study the monthly influence ranking of top repositories.

  1. Determination of Four Major Saponins in Skin and Endosperm of Seeds of Horse Chestnut (Aesculus Hippocastanum L.) Using High Performance Liquid Chromatography with Positive Confirmation by Thin Layer Chromatography

    OpenAIRE

    Abudayeh, Zead Helmi Mahmoud; Al Azzam, Khaldun Mohammad; Naddaf, Ahmad; Karpiuk, Uliana Vladimirovna; Kislichenko, Viktoria Sergeevna

    2015-01-01

    urpose: To separate and quantify four major saponins in the extracts of the skin and the endosperm of seeds of horse chestnut (Aesculus hippocastanum L.) using ultrasonic solvent extraction followed by a high performance liquid chromatography-diode array detector (HPLC-DAD) with positive confirmation by thin layer chromatography (TLC). Methods: The saponins: escin Ia, escin Ib, isoescin Ia and isoescin Ib were extracted using ultrasonic extraction method. The optimized ex...

  2. DECOVALEX III/BENCHPAR PROJECTS. Approaches to Upscaling Thermal-Hydro-Mechanical Processes in a Fractured Rock. Mass and its Significance for Large-Scale Repository Performance Assessment. Summary of Findings. Report of BMT2/WP3

    International Nuclear Information System (INIS)

    Andersson, Johan; Staub, Isabelle; Knight, Les

    2005-02-01

    The Benchmark Test 2 of DECOVALEX III and Work Package 3 of BENCHPAR concerns the upscaling Thermal (T), Hydrological (H) and Mechanical (M) processes in a fractured rock mass and its significance for large-scale repository performance assessment. The work is primarily concerned with the extent to which various thermo-hydro-mechanical couplings in a fractured rock mass adjacent to a repository are significant in terms of solute transport typically calculated in large-scale repository performance assessments. Since the presence of even quite small fractures may control the hydraulic, mechanical and coupled hydromechanical behaviour of the rock mass, a key of the work has been to explore the extent to which these can be upscaled and represented by 'equivalent' continuum properties appropriate PA calculations. From these general aims the BMT was set-up as a numerical study of a large scale reference problem. Analysing this reference problem should: help explore how different means of simplifying the geometrical detail of a site, with its implications on model parameters, ('upscaling') impacts model predictions of relevance to repository performance, explore to what extent the THM-coupling needs to be considered in relation to PA-measures, compare the uncertainties in upscaling (both to uncertainty on how to upscale or uncertainty that arises due to the upscaling processes) and consideration of THM couplings with the inherent uncertainty and spatial variability of the site specific data. Furthermore, it has been an essential component of the work that individual teams not only produce numerical results but are forced to make their own judgements and to provide the proper justification for their conclusions based on their analysis. It should also be understood that conclusions drawn will partly be specific to the problem analysed, in particular as it mainly concerns a 2D application. This means that specific conclusions may have limited applicability to real problems in

  3. DECOVALEX III III/BENCHPAR PROJECTS. Approaches to Upscaling Thermal-Hydro-Mechanical Processes in a Fractured Rock. Mass and its Significance for Large-Scale Repository Performance Assessment. Summary of Findings. Report of BMT2/WP3

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan (comp.) [JA Streamflow AB, Aelvsjoe (Sweden); Staub, Isabelle (comp.) [Golder Associates AB, Stockholm (Sweden); Knight, Les (comp.) [Nirex UK Ltd, Oxon (United Kingdom)

    2005-02-15

    The Benchmark Test 2 of DECOVALEX III and Work Package 3 of BENCHPAR concerns the upscaling Thermal (T), Hydrological (H) and Mechanical (M) processes in a fractured rock mass and its significance for large-scale repository performance assessment. The work is primarily concerned with the extent to which various thermo-hydro-mechanical couplings in a fractured rock mass adjacent to a repository are significant in terms of solute transport typically calculated in large-scale repository performance assessments. Since the presence of even quite small fractures may control the hydraulic, mechanical and coupled hydromechanical behaviour of the rock mass, a key of the work has been to explore the extent to which these can be upscaled and represented by 'equivalent' continuum properties appropriate PA calculations. From these general aims the BMT was set-up as a numerical study of a large scale reference problem. Analysing this reference problem should: help explore how different means of simplifying the geometrical detail of a site, with its implications on model parameters, ('upscaling') impacts model predictions of relevance to repository performance, explore to what extent the THM-coupling needs to be considered in relation to PA-measures, compare the uncertainties in upscaling (both to uncertainty on how to upscale or uncertainty that arises due to the upscaling processes) and consideration of THM couplings with the inherent uncertainty and spatial variability of the site specific data. Furthermore, it has been an essential component of the work that individual teams not only produce numerical results but are forced to make their own judgements and to provide the proper justification for their conclusions based on their analysis. It should also be understood that conclusions drawn will partly be specific to the problem analysed, in particular as it mainly concerns a 2D application. This means that specific conclusions may have limited applicability

  4. Repository-based software engineering program

    Science.gov (United States)

    Wilson, James

    1992-01-01

    The activities performed during September 1992 in support of Tasks 01 and 02 of the Repository-Based Software Engineering Program are outlined. The recommendations and implementation strategy defined at the September 9-10 meeting of the Reuse Acquisition Action Team (RAAT) are attached along with the viewgraphs and reference information presented at the Institute for Defense Analyses brief on legal and patent issues related to software reuse.

  5. Groundwater flow modelling of an abandoned partially open repository

    Energy Technology Data Exchange (ETDEWEB)

    Bockgaard, Niclas (Golder Associates AB (Sweden))

    2010-12-15

    As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

  6. Groundwater flow modelling of an abandoned partially open repository

    International Nuclear Information System (INIS)

    Bockgaard, Niclas

    2010-12-01

    As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

  7. Model confirmation in climate economics

    Science.gov (United States)

    Millner, Antony; McDermott, Thomas K. J.

    2016-01-01

    Benefit–cost integrated assessment models (BC-IAMs) inform climate policy debates by quantifying the trade-offs between alternative greenhouse gas abatement options. They achieve this by coupling simplified models of the climate system to models of the global economy and the costs and benefits of climate policy. Although these models have provided valuable qualitative insights into the sensitivity of policy trade-offs to different ethical and empirical assumptions, they are increasingly being used to inform the selection of policies in the real world. To the extent that BC-IAMs are used as inputs to policy selection, our confidence in their quantitative outputs must depend on the empirical validity of their modeling assumptions. We have a degree of confidence in climate models both because they have been tested on historical data in hindcasting experiments and because the physical principles they are based on have been empirically confirmed in closely related applications. By contrast, the economic components of BC-IAMs often rely on untestable scenarios, or on structural models that are comparatively untested on relevant time scales. Where possible, an approach to model confirmation similar to that used in climate science could help to build confidence in the economic components of BC-IAMs, or focus attention on which components might need refinement for policy applications. We illustrate the potential benefits of model confirmation exercises by performing a long-run hindcasting experiment with one of the leading BC-IAMs. We show that its model of long-run economic growth—one of its most important economic components—had questionable predictive power over the 20th century. PMID:27432964

  8. Bacteriologically confirmed tuberculosis in children

    International Nuclear Information System (INIS)

    Ozere, I.; Sele, A.; Ozolina, A.

    2005-01-01

    manifestation of bacteriologically confirmed TB in children is varied covering wide range from asymptomatic, on conventional X-ray invisible inthrathoracic adenopathy up to advanced disease. 2. Excretion of MT can occur in early stages of the TB before the disease becomes visible on conventional radiological examination and even on CT. 3. High-isoniazid resistance level of isolates makes reasonable the commensement of antituberculosis therapy with 4 first line drugs in every newly diagnosed case 4. The prophylactic treatment of latent tuberculosis infection is limited essentially by high isoniazid-resistance level of isolates. 5. None of the diagnostic criteria including chest CT has reliable sensitivity for diagnosing of TB in children. 6. In every case, if the child has positive tuberculin skin test and / or TB contact history, full diagnostic complex has to be performed, including chest CT and bacteriology

  9. Repository for fissile materials

    International Nuclear Information System (INIS)

    Gablin, K.A.

    1976-01-01

    A repository for holding and storing fissile or other hazardous materials either under or above the ground is provided by enclosing one or more inner containers, such as standard steel drums, in a larger, corrosion-resistant outer shell, with a layer of foamed polyurethane occupying the space therebetween. The polyurethane foam is free of voids at its interfaces with the inner container and outer shell, and adheres to and reinforces same to provide a stress skin structure. Protection is afforded by the chemical and physical characteristics of the polyurethane foam against destructive influences such as water vapor intrusion, package leakage and damaging effects of the environment, such as freezing, electrolysis, chemical and bacterial action. The outer shell is shaped to conform generally to the shape of the inner container and is made of a tube of bituminized fiber material with endcaps of exterior grade plywood treated with wood preservative. A quantity of fluorescein dye is positioned within the inner container for monitoring each package for leakage

  10. Biospecimen repositories and cytopathology.

    Science.gov (United States)

    Krishnamurthy, Savitri

    2015-03-01

    Biospecimen repositories are important for the advancement of biomedical research. Literature on the potential for biobanking of fine-needle aspiration, gynecologic, and nongynecologic cytology specimens is very limited. The potential for biobanking of these specimens as valuable additional resources to surgically excised tissues appears to be excellent. The cervicovaginal specimens that can be used for biobanking include Papanicolaou-stained monolayer preparations and residual material from liquid-based cytology preparations. Different types of specimen preparations of fine-needle aspiration and nongynecologic specimens, including Papanicolaou-stained and Diff-Quik-stained smears, cell blocks. and dedicated passes/residual material from fine-needle aspiration stored frozen in a variety of solutions, can be used for biobanking. Because of several gaps in knowledge regarding the standard of operative procedures for the procurement, storage, and quality assessment of cytology specimens, further studies as well as national conferences and workshops are needed not only to create awareness but also to facilitate the use of cytopathology specimens for biobanking. © 2014 American Cancer Society.

  11. VHA Data Sharing Agreement Repository

    Data.gov (United States)

    Department of Veterans Affairs — The VHA Data Sharing Agreement Repository serves as a centralized location to collect and report on agreements that share VHA data with entities outside of VA. It...

  12. NIH Common Data Elements Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Common Data Elements (CDE) Repository has been designed to provide access to structured human and machine-readable definitions of data elements that have...

  13. Privacy Impact Assessment (PIA) Repository

    Data.gov (United States)

    Department of Veterans Affairs — This repository contains Privacy Impact Assessments (PIA) that have been vetted/approved. Section 208 of the Electronic Government Act of 2002 (E-Gov Act) requires...

  14. Summary of repository siting models. Final report

    International Nuclear Information System (INIS)

    Thomas, S.D.; Ross, B.; Mercer, J.W.

    1982-07-01

    This report is the first in a series of reports that will provide critical reviews and summaries of computer programs that can be used to analyze the potential performance of a high-level radioactive waste repository. The computer programs identified address the following phenomena: saturated and unsaturated subsurface flow, heat transport, solute transport, surface water runoff, geomechanical interactions, and geochemical interactions. The report identifies 183 computer programs that can be used to analyze a repository site and provides a summary description of 31 computer programs. The summary descriptions can be used: to assist in code evaluation, to facilitate code comparison, to determine applicability of codes to specific problems, to identify code deficiencies, and to provide a screening mechanism for code selection

  15. The environmental constraint needs for design improvements to the Saligny I/LLW-repository near Cernavoda NPP

    International Nuclear Information System (INIS)

    Barariu, Gheorghe

    2007-01-01

    The paper presents the new perspectives on the development of the L/ILW Final Repository Project which will be built near Cernavoda NPP. The Repository is designed to satisfy the main performance objectives in accordance to IAEA recommendation. Starting in October 1996, Romania became a country with an operating nuclear power plant. Reactor 2 reached the criticality on May 6, 2007 and it will be put in commercial operation in September 2007. The Ministry of Economy and Finance has decided to proceed with the commissioning of Units 3 and 4 of Cernavoda NPP till 2014. The Strategy for radioactive waste management was elaborated by National Agency for Radioactive Waste (ANDRAD), the jurisdictional authority for definitive disposal and the coordination of nuclear spent fuel and radioactive waste management (Order 844/2004) with attributions established by Governmental Decision (GO) 31/2006. The Strategy specifies the commissioning of the Saligny L/IL Radwaste Repository near Cernavoda NPP in 2014. When designing the L/IL Radwaste Repository, the following prerequisites have been taken into account: 1) Cernavoda NPP will be equipped with 4 Candu 6 units. 2) National Legislation in radwaste management will be reviewed and/or completed to harmonize with UE standards 3) The selected site is now in process of confirmation after a comprehensive set of interdisciplinary investigations. (author)

  16. Conceptual design of repository facilities

    International Nuclear Information System (INIS)

    Beale, H.; Engelmann, H.J.; Souquet, G.; Mayence, M.; Hamstra, J.

    1980-01-01

    As part of the European Economic Communities programme of research into underground disposal of radioactive wastes repository design studies have been carried out for application in salt deposits, argillaceous formations and crystalline rocks. In this paper the design aspects of repositories are reviewed and conceptual designs are presented in relation to the geological formations under consideration. Emphasis has been placed on the disposal of vitrified high level radioactive wastes although consideration has been given to other categories of radioactive waste

  17. Business models for digital repositories

    CERN Document Server

    CERN. Geneva; Bjørnshauge, Lars

    2007-01-01

    Those setting up, or planning to set up, a digital repository may be interested to know more about what has gone before them. What is involved, what is the cost, how many people are needed, how have others made the case to their institution, and how do you get anything into it once it is built? I have recently undertaken a study of European repository business models for the DRIVER project and will present an overview of the findings.

  18. IAEA safeguards for geological repositories

    International Nuclear Information System (INIS)

    Moran, B.W.

    2005-01-01

    In September. 1988, the IAEA held its first formal meeting on the safeguards requirements for the final disposal of spent fuel and nuclear material-bearing waste. The consensus recommendation of the 43 participants from 18 countries at this Advisory Group Meeting was that safeguards should not terminate of spent fuel even after emplacement in, and closure of, a geologic repository.' As a result of this recommendation, the IAEA initiated a series of consultants' meetings and the SAGOR Programme (Programme for the Development of Safeguards for the Final Disposal of Spent Fuel in Geologic Repositories) to develop an approach that would permit IAEA safeguards to verify the non-diversion of spent fuel from a geologic repository. At the end of this process, in December 1997, a second Advisory Group Meeting, endorsed the generic safeguards approach developed by the SAGOR Programme. Using the SAGOR Programme results and consultants' meeting recommendations, the IAEA Department of Safeguards issued a safeguards policy paper stating the requirements for IAEA safeguards at geologic repositories. Following approval of the safeguards policy and the generic safeguards approach, the Geologic Repository Safeguards Experts Group was established to make recommendations on implementing the safeguards approach. This experts' group is currently making recommendations to the IAEA regarding the safeguards activities to be conducted with respect to Finland's repository programme. (author)

  19. Corrosion phase formation on container alloys in basalt repository environments

    International Nuclear Information System (INIS)

    Johnston, R.G.; Anantatmula, R.P.; Lutton, J.M.; Rivera, C.L.

    1986-01-01

    The Basalt Waste Isolation Project is evaluating the suitability of basalt in southeastern Washington State as a possible location for a nuclear waste repository. The performance of the waste package, which includes the waste form, container, and surrounding packing material, will be affected by the stability of container alloys in the repository environment. Primary corrosion phases and altered packing material containing metals leached from the container may also influence subsequent reactions between the waste form and repository environment. Copper- and iron-based alloys were tested at 50 0 to 300 0 C in an air/steam environment and in pressure vessels in ground-water-saturated basalt-bentonite packing material. Reaction phases formed on the alloys were identified and corrosion rates were measured. Changes in adhering packing material were also evaluated. The observed reactions and their possible effects on container alloy durability in the repository are discussed

  20. Radioactive waste repository of high ecological safety

    International Nuclear Information System (INIS)

    Sobolev, I.; Barinov, A.; Prozorov, L.

    2000-01-01

    With the purpose to construct a radioactive waste repository of high ecological safety and reliable containment, MosNPO 'Radon' specialists have developed an advanced type repository - large diameter well (LBD) one. A project is started for the development of a technology for LDW repository construction and pilot operation of the new repository for 25-30 years. The 2 LDW repositories constructed at the 'Radon' site and the developed monitoring system are described

  1. Demystifying the institutional repository for success

    CERN Document Server

    Buehler, Marianne

    2013-01-01

    Institutional repositories remain key to data storage on campus, fulfilling the academic needs of various stakeholders. Demystifying the Institutional Repository for Success is a practical guide to creating and sustaining an institutional repository through marketing, partnering, and understanding the academic needs of all stakeholders on campus. This title is divided into seven chapters, covering: traditional scholarly communication and open access publishing; the academic shift towards open access; what the successful institutional repository looks like; institutional repository collaboratio

  2. Virtual patient repositories--a comparative analysis.

    Science.gov (United States)

    Küfner, Julia; Kononowicz, Andrzej A; Hege, Inga

    2014-01-01

    Virtual Patients (VPs) are an important component of medical education. One way to reduce the costs for creating VPs is sharing through repositories. We conducted a literature review to identify existing repositories and analyzed the 17 included repositories in regards to the search functions and metadata they provide. Most repositories provided some metadata such as title or description, whereas other data, such as educational objectives, were less frequent. Future research could, in cooperation with the repository provider, investigate user expectations and usage patterns.

  3. Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage. Progress report on NUMO-JAEA collaborative research in FY2011 (Joint research)

    International Nuclear Information System (INIS)

    Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; Semba, Takeshi; Hioki, Kazumasa; Kamei, Gento; Ebashi, Takeshi; Kubota, Shigeru; Kurosawa, Susumu; Goto, Junichi; Goto, Takahiro; Ishii, Eiichi; Inagaki, Manabu; Moriya, Toshifumi; Suzuki, Satoru; Ohi, Takao; Ichihara, Takayuki; Ishida, Keisuke; Ishiguro, Katsuhiko; Tsuchi, Hiroyuki

    2012-09-01

    JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. The topics of such joint research are (1) study on selection of host rock, (2) study on development of scenario, (3) study on setting nuclide migration parameters, (4) study on ensuring quality of knowledge. With regard to (1), in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. With regard to (2), the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. With regard to (3), the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. With regard to (4), framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition. (author)

  4. Prestudy Oskarshamn. Tourism in Oskarshamn with or without a repository; Foerstudie Oskarshamn. Turismen i Oskarshamn med eller utan djupfoervar

    Energy Technology Data Exchange (ETDEWEB)

    Nordblom, C.J.; Foghagen, C. [Hoegskolan i Kalmar (Sweden). Inst. foer samhaellsvetenskap med ekonomi

    1998-11-01

    Consequences for the tourism at Oskarshamn from siting a spent fuel repository in the community are studied. Four questionnaire/interview enquires were performed, and the analysis of the results show that no noticeable effects are expected. Still, an uncertainty about the impact of a repository is felt by the public, and more thorough information about the repository and its components is needed

  5. Effect of organic carbon content of the domestic bentonite on the performance of buffer material in a high-level waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Lee, Jae Owan; Kang, Chul Hyung [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    The organic carbon content of the domestic bentonite have been measured, and its effects on the performance of buffer are analyzed. The total carbon content and the organic carbon content were in the range of 3160 to 3600 and 2400 to 2800 ppm, respectively. The aqueous phase equilibrium concentrations of total carbon and organic carbon in bentonite-water mixture were in the range of 25 to 50 ppm and 4 to 18 ppm, respectively. The results indicate that the effect of organic matter in the domestic bentonite on the performance of buffer material were insignificant. 33 refs., 15 figs., 10 tabs. (Author)

  6. Design and Performance Assessment of a Conceptual Cover Cap of Near Surface Repository for Short Lived Low and Intermediate Level Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Asaba, Ruth; Kim, Changlak [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-05-15

    The safety of the overall waste disposal system is determined by the performance of its individual components: waste form, waste container, engineered barrier and the host environment. The design of the cover cap helps in preventing percolation of water, and in retarding radionuclide migration from the disposal facility to the biosphere. The cover of a disposal facility is usually a combination of materials such as sand, gravel, concrete, clay and soil conditioned for vegetation growth. The cover system will be designed using models such as EPA's Hydrological Evaluation of Land fill Performance (HELP) code. This paper describes a conceptual design for a cover cap for a land fill as a preferred disposal facility for low and short lived intermediate radioactive waste in Uganda. Majority of the waste is generated from disused sealed and unsealed radioactive sources arising from medical, industrial applications, and research. Radioactive waste management has raised a lot of concern in both developed and developing countries. Each country has a responsibility to come up with a solution to prevent contamination of the environment and humans from radioactive waste. It is important to have thicker soil layers in cap designs so as to support vegetation growth since some activities such as erosion and settlements are expected. Help simulations in this study will assist to demonstrate that it is possible to design a cover cap which can contain radioactive waste packages for hundreds of years provided the proper institutional and performance monitoring schemes are implemented.

  7. Compliance with NRC subsystem requirements in the repository licensing process

    International Nuclear Information System (INIS)

    Minwalla, H.

    1994-01-01

    Section 121 of the Nuclear Waste Policy Act of 1982 requires the Nuclear Regulatory Commission (Commission) to issue technical requirements and criteria, for the use of a system of multiple barriers in the design of the repository, that are not inconsistent with any comparable standard promulgated by the Environmental Protection Agency (EPA). The Administrator of the EPA is required to promulgate generally applicable standards for protection of the general environment from offsite releases from radioactive material in repositories. The Commission's regulations pertaining to geologic repositories are provided in 10 CFR part 60. The Commission has provided in 10 CFR 60.112 the overall post-closure system performance objective which is used to demonstrate compliance with the EPA high-level waste (HLW) disposal standard. In addition, the Commission has provided, in 10 CFR 60.113, subsystem performance requirements for substantially complete containment, fractional release rate, and groundwater travel time; however, none of these subsystem performance requirements have a causal technical nexus with the EPA HLW disposal standard. This paper examines the issue of compliance with the conflicting dual regulatory role of subsystem performance requirements in the repository licensing process and recommends several approaches that would appropriately define the role of subsystem performance requirements in the repository licensing process

  8. Biological Web Service Repositories Review.

    Science.gov (United States)

    Urdidiales-Nieto, David; Navas-Delgado, Ismael; Aldana-Montes, José F

    2017-05-01

    Web services play a key role in bioinformatics enabling the integration of database access and analysis of algorithms. However, Web service repositories do not usually publish information on the changes made to their registered Web services. Dynamism is directly related to the changes in the repositories (services registered or unregistered) and at service level (annotation changes). Thus, users, software clients or workflow based approaches lack enough relevant information to decide when they should review or re-execute a Web service or workflow to get updated or improved results. The dynamism of the repository could be a measure for workflow developers to re-check service availability and annotation changes in the services of interest to them. This paper presents a review on the most well-known Web service repositories in the life sciences including an analysis of their dynamism. Freshness is introduced in this paper, and has been used as the measure for the dynamism of these repositories. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  9. Multibarrier system preventing migration of radionuclides from radioactive waste repository

    Directory of Open Access Journals (Sweden)

    Olszewska Wioleta

    2015-09-01

    Full Text Available Safety of radioactive waste repositories operation is associated with a multibarrier system designed and constructed to isolate and contain the waste from the biosphere. Each of radioactive waste repositories is equipped with system of barriers, which reduces the possibility of release of radionuclides from the storage site. Safety systems may differ from each other depending on the type of repository. They consist of the natural geological barrier provided by host rocks of the repository and its surroundings, and an engineered barrier system (EBS. The EBS may itself comprise a variety of sub-systems or components, such as waste forms, canisters, buffers, backfills, seals and plugs. The EBS plays a major role in providing the required disposal system performance. It is assumed that the metal canisters and system of barriers adequately isolate waste from the biosphere. The evaluation of the multibarrier system is carried out after detailed tests to determine its parameters, and after analysis including mathematical modeling of migration of contaminants. To provide an assurance of safety of radioactive waste repository multibarrier system, detailed long term safety assessments are developed. Usually they comprise modeling of EBS stability, corrosion rate and radionuclide migration in near field in geosphere and biosphere. The principal goal of radionuclide migration modeling is assessment of the radionuclides release paths and rate from the repository, radionuclides concentration in geosphere in time and human exposure to ionizing radiation

  10. An analysis of repository waste-handling operations

    International Nuclear Information System (INIS)

    Dennis, A.W.

    1990-09-01

    This report has been prepared to document the operational analysis of waste-handling facilities at a geologic repository for high-level nuclear waste. The site currently under investigation for the geologic repository is located at Yucca Mountain, Nye County, Nevada. The repository waste-handling operations have been identified and analyzed for the year 2011, a steady-state year during which the repository receives spent nuclear fuel containing the equivalent of 3000 metric tons of uranium (MTU) and defense high-level waste containing the equivalent of 400 MTU. As a result of this analysis, it has been determined that the waste-handling facilities are adequate to receive, prepare, store, and emplace the projected quantity of waste on an annual basis. In addition, several areas have been identified where additional work is required. The recommendations for future work have been divided into three categories: items that affect the total waste management system, operations within the repository boundary, and the methodology used to perform operational analyses for repository designs. 7 refs., 48 figs., 11 tabs

  11. Classifying decommissioning wastes for allocation to appropriate final repositories

    International Nuclear Information System (INIS)

    Alder, J.C.; Tunaboylu, K.

    1982-01-01

    For the safe disposal of radioactive wastes in different repositories, it is of advantage to classify them in well-defined conditioned categories, appropriate for final disposal. These categories, the so-called waste sorts are characterized by similar radionuclide distribution, similar nuclide-specific activity concentrations and similar waste matrix. A methodology is presented for classifying decommissioning wastes and is applied to the decommissioning wastes arising from a Swiss program of 6 GWe. The amounts and nuclide-specific activity inventories of the decommissioning waste sorts have been estimated. A first allocation into two different repository types has been performed. Such a classification enables one to define the source parameters for repository safety analysis and allows one to allocate the different waste categories into appropriate final repositories. This work presents a first iteration to determine which waste sorts belong to which repository type. The characteristics of waste sorts have to be better defined and the protective strength of the repository barriers has to be optimized. 7 references, 2 figures, 4 tables

  12. Geotechnical instrumentation requirements for atdepth testing and repository monitoring in tuff

    International Nuclear Information System (INIS)

    Zimmerman, R.M.

    1983-01-01

    This paper outlines geotechnical instrumentation requirements for the possible establishment of a nuclear waste repository in tuff on the Nevada Test Site (NTS). The Nuclear Regulatory Commission (NRC) has specified a continuing program to confirm performance during the operational period of the repository, which could last 50 years. Minimum required geotechnical measurements for confirmation of performance include thermal and thermomechanical responses; changes in stress, strain, and displacements; and pore pressure and groundwater flow characteristics. Conditions expected in tuff are: maximum rock temperatures of less than 250 0 C, stresses less than 100 MPa, strains between + or -0.01 mm/mm, and pore pressures less than 35 KPa in the unsaturated zone where hydraulic head is not the primary contributor. The paper describes instrumentation needed to make the desired measurements. In general, the instrumentation and data system are required to be stable and reliable for tens of years. Designs must consider requirements for temperature stability, temperature expansion compensation, moisture resistance, and long-term durability in mining-type environments. Severe requirements such as these suggest consideration of techniques for in-situ replacement of instrumentation. State-of-the-art instrumentation is briefly described along with a discussion of needs for refinement, replacement/recalibration and instrumentation development

  13. Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

    International Nuclear Information System (INIS)

    1985-10-01

    Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin

  14. The Ec prototype repository project: implications of assessments for refining repository design

    International Nuclear Information System (INIS)

    Svemar, C.

    2004-01-01

    The most important issue in the evaluation of the repository performance is the long term safety of the repository. Analyses for this issue focuses on the 'steady state' conditions which start at the time when the repository has been saturated and the groundwater table returned to its normal level. The bentonite buffer around the canisters is saturated and homogeneous, and the canister is located exactly in the centre of the buffer. The backfill in the tunnel has been saturated as well and fills the earlier open spaces in the tunnel completely. The task of the activities taking places prior to the start of the 'steady state' conditions, like excavation, deposition, backfilling and sealing, with due consideration to the processes a consequences they may cause in the long run, is to provide for these 'ideal' conditions, as close as possible. While studying these activities in detail it has become obvious that development of methods and techniques needs to be carefully addressed before the decision is made on how to apply them in the repository. One general finding is that the situation in engineering of details is not that much different from the situation in geological characterisation of a site in detail; one more detail of engineering and the consequences it brings often complicates the situation rather than supports the solution prioritized so far. Many of the practical issues have been studied in the Prototype Repository project in the AEspoe Hard Rock Laboratory (Pusch et al., 2000). The Prototype Repository consists of two sections with four respectively two deposition holes with bentonite buffer and canister, the latter holding electrical heaters. The sections are separated by a concrete plug, and the whole test is to be separated from the rest of the laboratory by an outer plug. The project has two objectives: 1. To demonstrate the integrated function of tile deep repository components under realistic conditions and to compare results with models and

  15. Harvesting NASA's Common Metadata Repository

    Science.gov (United States)

    Shum, D.; Mitchell, A. E.; Durbin, C.; Norton, J.

    2017-12-01

    As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

  16. International perspective on repositories for low level waste

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Pers, Karin; Almen, Ylva

    2011-12-01

    Nuclear energy production gives rise to different types of radioactive waste. The use of nuclear isotopes within the research, industry and medical sectors also generates radioactive waste. To protect man and the environment from radiation the waste is isolated and contained by deposition in repositories. These repositories may have various designs regarding location, barriers etc depending on the potential danger of the waste. In Sweden, low- and intermediate level waste (LILW) is disposed of in the SFR repository in Forsmark. The repository is located 60 metres down into the bedrock under the bottom of the sea and covered by 6 metres of water. It is planned to extend SFR to accommodate decommissioning waste from the dismantling of the Swedish nuclear power facilities and also for the additional operation waste caused by the planned prolonged operation time. When planning the extension consultations will be carried out with the host municipality, authorities, organisations and general public. In planning the extension, SKB has performed a worldwide compilation of how other countries have, or plan to, handle the final disposal of similar wastes. The aim of this report is to give a brief description of LILW repositories worldwide; including general brief descriptions of many facilities, descriptions of the waste and the barriers as well as safety assessments for a few chosen repositories which represent different designs. The latter is performed, where possible, to compare certain features against the Swedish SFR. To provide a background and context to this study, international organisations and conventions are also presented along with internationally accepted principles regarding the management of radioactive waste. Similar to SFR, suitable locations for the repositories have, in many countries, been found at sites that already have, or used to have nuclear activities, such as reactor sites. Abandoned and disused mines, such as the salt mines in Germany, also

  17. International perspective on repositories for low level waste

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Pers, Karin; Almen, Ylva (SKB International AB (Sweden))

    2011-12-15

    Nuclear energy production gives rise to different types of radioactive waste. The use of nuclear isotopes within the research, industry and medical sectors also generates radioactive waste. To protect man and the environment from radiation the waste is isolated and contained by deposition in repositories. These repositories may have various designs regarding location, barriers etc depending on the potential danger of the waste. In Sweden, low- and intermediate level waste (LILW) is disposed of in the SFR repository in Forsmark. The repository is located 60 metres down into the bedrock under the bottom of the sea and covered by 6 metres of water. It is planned to extend SFR to accommodate decommissioning waste from the dismantling of the Swedish nuclear power facilities and also for the additional operation waste caused by the planned prolonged operation time. When planning the extension consultations will be carried out with the host municipality, authorities, organisations and general public. In planning the extension, SKB has performed a worldwide compilation of how other countries have, or plan to, handle the final disposal of similar wastes. The aim of this report is to give a brief description of LILW repositories worldwide; including general brief descriptions of many facilities, descriptions of the waste and the barriers as well as safety assessments for a few chosen repositories which represent different designs. The latter is performed, where possible, to compare certain features against the Swedish SFR. To provide a background and context to this study, international organisations and conventions are also presented along with internationally accepted principles regarding the management of radioactive waste. Similar to SFR, suitable locations for the repositories have, in many countries, been found at sites that already have, or used to have nuclear activities, such as reactor sites. Abandoned and disused mines, such as the salt mines in Germany, also

  18. Reference Design Description for a Geologic Repository

    International Nuclear Information System (INIS)

    2000-01-01

    One of the current major national environmental problems is the safe disposal of large quantities of spent nuclear fuel and high-level radioactive waste materials, which are rapidly accumulating throughout the country. These radioactive byproducts are generated as the result of national defense activities and from the generation of electricity by commercial nuclear power plants. At present, spent nuclear fuel is accumulating at over 70 power plant sites distributed throughout 33 states. The safe disposal of these high-level radioactive materials at a central disposal facility is a high national priority. This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada for the disposal of spent nuclear fuel and high-level radioactive waste materials. This document describes a possible design for the three fundamental parts of a repository: a surface facility, subsurface repository, and waste packaging. It also presents the current conceptual design of the key engineering systems for the final four phases of repository processes: operations, monitoring, closure, and postclosure. In accordance with current law, this design does not include an interim storage option. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. It describes the natural barrier system which, together with the engineered systems, achieves the repository objectives. This design will protect the public and the environment by allowing the safe disposal of radioactive waste received from government-owned custodial spent fuel sites, high-level radioactive waste sites, and commercial power reactor sites. All design elements meet or exceed applicable regulations governing the disposal of high-level radioactive waste. The design will provide safe disposal of waste materials for at least a 10,000 year period. During this time interval, natural radioactive decay

  19. Overly Honest Data Repository Development

    Directory of Open Access Journals (Sweden)

    Colleen Fallaw

    2016-10-01

    Full Text Available After a year of development, the library at the University of Illinois at Urbana-Champaign has launched a repository, called the Illinois Data Bank (https://databank.illinois.edu/, to provide Illinois researchers with a free, self-serve publishing platform that centralizes, preserves, and provides persistent and reliable access to Illinois research data. This article presents a holistic view of development by discussing our overarching technical, policy, and interface strategies. By openly presenting our design decisions, the rationales behind those decisions, and associated challenges this paper aims to contribute to the library community's work to develop repository services that meet growing data preservation and sharing needs.

  20. Studies on an advanced repository system with enhanced engineered barriers (a framework)

    International Nuclear Information System (INIS)

    Fujiwara, A.; Tashiro, S.; Ikari, S.; Suzuki, A.

    1993-01-01

    In order to propose advanced designs of repositories with enhanced engineered barriers of relatively high radioactive wastes such as burnable poisons, channel boxes, control rods and highly irradiated metals, studies started in 1987 and completed the first phase in 1992. This paper presents the framework and brief results of the first phase. The studies set preliminary design concepts of the repositories with various combinations with engineered barriers and natural barriers for different models and locations such as a silo type in shallow land or a tunnel type in intermediate depth. Through the designs, four component technics were picked up and studied for (1) construction of the components in repository; (2) performance evaluation to realize repository design; (3) improvement of circumstances inside or around repository; and (4) surveillance of repository performance to realize the repository designs. Finally, some repository systems were provided using obtained results, and then the applicability and the economy were evaluated. The studies will continue to the second phase focusing on the long-term performance of the repositories

  1. Developing of Radioactive Wastes Management Safety at Baldone Repository Radons

    International Nuclear Information System (INIS)

    Abramenkovs, A.; Abramenkova, G.; Klavins, M.

    2008-01-01

    The near surface radioactive wastes repository Radons near the Baldone city was put in operation in 1962. The safety assessment of repository was performed during 2000-2001 under the PHARE project to evaluate the recommended upgrades of repository. The outline design for new vaults and interim storage for long lived radioactive wastes was elaborated during 2003-2004 years. The Environmental Impact Assessment (EIA) for upgrade of Baldone repository was performed during 2004-2005 years. Additional evaluations of radioactive wastes management safety were performed during 2006 year by the experts of ENRESA, Spain. It was shown, that the additional efforts were spent for improving of radioactive wastes cementation in concrete containers. The results of tritium and Cs 137 leaching studies are presented and discussed. It was shown, that additives can significantly reduce the migration of radionuclides in ground water. The leaching coefficients for tritium and Cs 137 were determined to supply with the necessary data the risk assessment calculations for operation of Baldone repository R adons

  2. Scrapping of student bursaries confirmed.

    Science.gov (United States)

    Longhurst, Chris

    2016-07-27

    Student bursaries for nurses will be scrapped from next year, the government has confirmed. Undergraduate nursing and midwifery students in England will now face tuition fees and student loans from August 2017.

  3. Selective enrichment of volatiles confirmed

    Science.gov (United States)

    de Pater, Imke

    2018-05-01

    Hydrogen sulfide gas is detected above Uranus's main cloud deck, confirming the prevalence of H2S ice particles as the main cloud component and a strongly unbalanced nitrogen/sulfur ratio in the planet's deep atmosphere.

  4. Continuing Science and Technology at the Proposed Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Finch, R.J.

    2005-01-01

    Yucca Mountain, Nevada, was designated in 2002 to be the site for the nation's first permanent geological repository for spent nuclear fuel and high-level radioactive waste. The process of selecting a site for the repository began nearly 25 years ago with passage of the Nuclear Waste Policy Act in 1982. The Department of Energy (DOE) is responsible for submitting a license application to the Nuclear Regulatory Commission for constructing and operating the repository, and DOE's Office of Civilian Radioactive Waste Management (OCRWM) is charged with carrying out this action. The use of multiple natural and engineered barriers in the current repository design are considered by OCRWM to be sufficiently robust to warrant license approval; however, potential design enhancements and increased understanding of both natural and engineered barriers, especially over the long time frames during which the waste is to remain isolated from human contact continue to be examined. The Office of Science and Technology and International (OST andI) was created within OCRWM to help explore novel technologies that might lower overall costs and to develop a greater understanding of processes relevant to the long-term performance of the repository. A brief overview of Yucca Mountain, and the role that OST andI has in identifying technological or scientific advances that could make repository operations more efficient or performance more robust, will be presented. It is important to note, however, that adopting any of OST andI's technological or scientific developments will be at the discretion of OCRWM's Office of Repository Development (ORD)

  5. Oxidation-reduction reactions. Overview and implications for repository studies

    International Nuclear Information System (INIS)

    Apted, Michael J.; Arthur, Randolph C.; Sasamoto, Hiroshi; Yui, Mikazu; Iwatsuki, Teruki

    2001-02-01

    The purpose of this report is to provide a survey and review on oxidation-reduction ('redox') reactions, with particular emphasis on implications for disposal of high-level waste (HLW) in deep geological formations. As an overview, the focus is on basic principles, problems, and proposed research related specifically to the assessment of redox for a HLW repository in Japan. For a more comprehensive treatment of redox and the myriad associated issues, the reader is directed to the cited textbooks used as primary references in this report. Low redox conditions in deep geological formations is a key assumption in the 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' (hereafter called H12'). The release behavior of multi-valent radioelements (e.g., Tc, Se, U, Pu, Np), as well as daughter radioelements of these radioelements, from a deep geological repository are sensitively related to redox conditions. Furthermore, the performance of certain barrier materials, such as overpack and buffer, may be impacted by redox conditions. Given this importance, this report summarizes some key topics for future technical studies supporting site characterization and repository performance as follows: To fully test the conceptual models for system Eh, it will be necessary to measure and evaluate trace element and isotopic information of both coexisting groundwater and reactive minerals of candidate rocks. Because of importance of volatile species (e.g., O 2 , H 2 etc.) in redox reactions, and given the high total pressure of a repository located 500 to 1000 meter deep, laboratory investigations of redox will necessarily require use of pressurized test devices that can fully simulate repository conditions. The stability (redox capacity) of the repository system with respect to potential changes in redox boundary condition induced by oxidizing waters intrusion should be established experimentally. An overall conceptual model that unifies

  6. Assessment of the Durability of Cementitious Materials in Repository Environment

    International Nuclear Information System (INIS)

    Vicente, R.; Marumo, J.T.; Miyamoto, H.; Isiki, V.L.K.; Ferreira, E.G.

    2013-01-01

    The Radioactive Waste Management Laboratory of the Energy and Nuclear Research Institute is developing the concept of a borehole repository for disused sealed radioactive sources drilled in a deep granite batholite. In this concept, the annular space between the well steel casing and the geological formation is backfilled with cement paste. The hardened cement paste functions as an additional barrier against the escape of radionuclides from the repository and their migration to the environment. It also functions as an obstacle to the flow of groundwater between different layers of the geological setting crossed by the borehole. The long term behavior of hydrated cement compounds is yet incompletely known and therefore more research is needed to increase the confidence on the performance of the material under the repository conditions as required. For the repository to achieve the required performance, the cement paste must be durable. However, in a deep repository, the cementitious materials is exposed to the deleterious action of high temperatures and pressures, the radiation field created by the radioactive sources and aggressive ion species that may be present in groundwater. Furthermore, it is necessary to consider that the cement paste is unstable in the long term because its microstructure and mineralogy change with time as the cement gel components recrystallize and react chemically with materials of the repository environment. In principle, the lifetime of this material could be determined based on the study of its long-term behavior, which, in turn, could be estimated from the extrapolation of short-term results, by accelerating, under controlled laboratory conditions, the composition changes and the loss of mechanical strength and cohesion induced by any detrimental component of the repository environment. Loss of mechanical strength, dimensional variations, changes in chemical-mineralogical composition, and leaching of hydrate compounds are all possible

  7. Chemical conditions in the repository for low- and intermediate-level reactor waste

    International Nuclear Information System (INIS)

    Snellman, M.; Uotila, H.

    1984-01-01

    The chemical conditions in the proposed repositories for low- and intermediate-level reactor waste at Haestholmen (IVO) and Olkiluoto (TVO) have been discussed with respect to materials introduced into the repository, their possible long-term changes and interaction with groundwater flowing into the repository. The main possible groundwater-rock interactions have been discussed, as well as the role of micro-organisms, organic acids and colloids in the estimation of the barrier integrity. Experimental and theoretical studies have been performed on the basis of the natural groundwater compositions expected at the repository sites. Main emphasis is put on the chemical parameters which might influence the integrity of the different barriers in the repository as well as on the parameters which might effect the release and transport of radionuclides from the repository

  8. Cancer Epidemiology Data Repository (CEDR)

    Science.gov (United States)

    In an effort to broaden access and facilitate efficient data sharing, the Epidemiology and Genomics Research Program (EGRP) has created the Cancer Epidemiology Data Repository (CEDR), a centralized, controlled-access database, where Investigators can deposit individual-level de-identified observational cancer datasets.

  9. Repository operational criteria comparative analysis

    International Nuclear Information System (INIS)

    Hageman, J.P.; Chowdhury, A.H.

    1994-06-01

    The objective of the ''Repository Operational Criteria (ROC) Feasibility Studies'' (or ROC task) was to conduct comprehensive and integrated analyses of repository design, construction, and operations criteria in 10 CFR Part 60 regulations considering the interfaces among the components of the regulations and impacts of any potential changes to those regulations. The ROC task addresses regulatory criteria and uncertainties related to the preclosure aspects of the geologic repository. Those parts of 10 CFR Part 60 that require routine guidance or minor changes to the rule were addressed in Hageman and Chowdhury, 1992. The ROC task shows a possible need for further regulatory clarity, by major changes to the rule, related to the design bases and siting of a geologic repository operations area and radiological emergency planning in order to assure defense-in-depth. The analyses, presented in this report, resulted in the development and refinement of regulatory concepts and their supporting rationale for recommendations for potential major changes to 10 CFR Pan 0 regulations

  10. LIFE Materials: Fuel Cycle and Repository Volume 11

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, H; Blink, J A

    2008-12-12

    to meet the thermal constraints of the repository design. (4) A simple, but arguably conservative, estimate for the dose from a repository containing 63,000 MT of spent LIFE fuel would have similar performance to the currently planned Yucca Mountain Repository. This indicates that a properly designed 'LIFE Repository' would almost certainly meet the proposed Nuclear Regulatory Commission standards for dose to individuals, even though the waste in such a repository would have produced 20-30 times more generated electricity than the reference case for Yucca Mountain. The societal risk/benefit ratio for a LIFE repository would therefore be significantly better than for currently planned repositories for LWR fuel.

  11. LIFE Materials: Fuel Cycle and Repository Volume 11

    International Nuclear Information System (INIS)

    Shaw, H.; Blink, J.A.

    2008-01-01

    the repository design. (4) A simple, but arguably conservative, estimate for the dose from a repository containing 63,000 MT of spent LIFE fuel would have similar performance to the currently planned Yucca Mountain Repository. This indicates that a properly designed 'LIFE Repository' would almost certainly meet the proposed Nuclear Regulatory Commission standards for dose to individuals, even though the waste in such a repository would have produced 20-30 times more generated electricity than the reference case for Yucca Mountain. The societal risk/benefit ratio for a LIFE repository would therefore be significantly better than for currently planned repositories for LWR fuel

  12. Hydrothermal modeling for the efficient design of thermal loading in a nuclear waste repository

    International Nuclear Information System (INIS)

    Cho, Won-Jin; Kim, Jin-Seop; Choi, Heui-Joo

    2014-01-01

    Highlights: • Three-dimensional hydrothermal modeling for HLW repository is performed. • The model reduces the peak temperature in the repository by about 10 °C. • Decreasing the tunnel distance is more efficient to improve the disposal density. • The EDZ surrounding the deposition hole increases the peak temperature. • The peak temperature for the double-layer repository remains below the limit. - Abstract: The thermal analysis of a geological repository for nuclear waste using the three-dimensional hydrothermal model is performed. The hydrothermal model reduces the maximum peak temperature in the repository by about 10 °C compared to the heat conduction model with constant thermal conductivities. Decreasing the tunnel distance is more efficient than decreasing the deposition hole spacing to improve the disposal density for a given thermal load. The annular excavation damaged zone surrounding the deposition hole has a considerable effect on the peak temperature. The possibility of double-layer repository is analyzed from the viewpoint of the thermal constraints of the repository. The maximum peak temperature for the double-layer repository is slightly higher than that for the single-layer repository, but remains below the temperature limit

  13. Monte Carlo simulations for generic granite repository studies

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Shaoping [Los Alamos National Laboratory; Lee, Joon H [SNL; Wang, Yifeng [SNL

    2010-12-08

    In a collaborative study between Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) for the DOE-NE Office of Fuel Cycle Technologies Used Fuel Disposition (UFD) Campaign project, we have conducted preliminary system-level analyses to support the development of a long-term strategy for geologic disposal of high-level radioactive waste. A general modeling framework consisting of a near- and a far-field submodel for a granite GDSE was developed. A representative far-field transport model for a generic granite repository was merged with an integrated systems (GoldSim) near-field model. Integrated Monte Carlo model runs with the combined near- and farfield transport models were performed, and the parameter sensitivities were evaluated for the combined system. In addition, a sub-set of radionuclides that are potentially important to repository performance were identified and evaluated for a series of model runs. The analyses were conducted with different waste inventory scenarios. Analyses were also conducted for different repository radionuelide release scenarios. While the results to date are for a generic granite repository, the work establishes the method to be used in the future to provide guidance on the development of strategy for long-term disposal of high-level radioactive waste in a granite repository.

  14. Underground excavation methods for a high-level waste repository

    International Nuclear Information System (INIS)

    Peshel, J.; Gupta, D.; Nataraja, M.

    1990-01-01

    This paper reports on rock excavation methods for a High-Level Waste repository that should be selected to limit the potential for creating preferential pathways for groundwater to travel to the waste packages or for radionuclides to migrate to the accessible environment. The use of water and other foreign substances should be controlled so that the repository performance is not compromised. The excavated openings should remain stable so that operations can be carried out safely and the retrievability option maintained. As per the current conceptual designs presented by the Department of Energy, the exploratory shaft facility becomes a part of the repository if the Yucca Mountain site is found suitable for repository development. Therefore, the methods of constructing the underground openings should be compatible with the performance requirements for the repository. Also, the degree of damage to the rock surrounding the openings and the extent of the damage zone should not preclude adequate site characterization. The ESf construction and operation should be compatible with the site data gathering activities, such as geological, thermomechanical, hydrological and geochemical testing

  15. Core Certification of Data Repositories: Trustworthiness and Long-Term Stewardship

    Science.gov (United States)

    de Sherbinin, A. M.; Mokrane, M.; Hugo, W.; Sorvari, S.; Harrison, S.

    2017-12-01

    Scientific integrity and norms dictate that data created and used by scientists should be managed, curated, and archived in trustworthy data repositories thus ensuring that science is verifiable and reproducible while preserving the initial investment in collecting data. Research stakeholders including researchers, science funders, librarians, and publishers must also be able to establish the trustworthiness of data repositories they use to confirm that the data they submit and use remain useful and meaningful in the long term. Data repositories are increasingly recognized as a key element of the global research infrastructure and the importance of establishing their trustworthiness is recognised as a prerequisite for efficient scientific research and data sharing. The Core Trustworthy Data Repository Requirements are a set of universal requirements for certification of data repositories at the core level (see: https://goo.gl/PYsygW). They were developed by the ICSU World Data System (WDS: www.icsu-wds.org) and the Data Seal of Approval (DSA: www.datasealofapproval.org)—the two authoritative organizations responsible for the development and implementation of this standard to be further developed under the CoreTrustSeal branding . CoreTrustSeal certification of data repositories involves a minimally intensive process whereby repositories supply evidence that they are sustainable and trustworthy. Repositories conduct a self-assessment which is then reviewed by community peers. Based on this review CoreTrustSeal certification is granted by the CoreTrustSeal Standards and Certification Board. Certification helps data communities—producers, repositories, and consumers—to improve the quality and transparency of their processes, and to increase awareness of and compliance with established standards. This presentation will introduce the CoreTrustSeal certification requirements for repositories and offer an opportunity to discuss ways to improve the contribution of

  16. Models and criteria for waste repository performance

    International Nuclear Information System (INIS)

    Smith, C.F.; Cohen, J.J.

    1981-03-01

    A primary objective of the Waste Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in assuring that this objective is met. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste management decision making. Criteria development needs and the relation between criteria and models are also discussed

  17. Consistency of Network Traffic Repositories: An Overview

    NARCIS (Netherlands)

    Lastdrager, E.; Lastdrager, E.E.H.; Pras, Aiko

    2009-01-01

    Traffc repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffc that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  18. Consistency analysis of network traffic repositories

    NARCIS (Netherlands)

    Lastdrager, Elmer; Lastdrager, E.E.H.; Pras, Aiko

    Traffic repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffic that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  19. Application of ultra-high-performance liquid chromatography coupled with LTQ-Orbitrap mass spectrometry for identification, confirmation and quantitation of illegal adulterated weight-loss drugs in plant dietary supplements.

    Science.gov (United States)

    Cheng, Qiaoyuan; Shou, Linjun; Chen, Cen; Shi, Shi; Zhou, Minghao

    2017-10-01

    In this paper, an ultra-high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high resolution mass spectrometry (UHPLC-LTQ-Orbitrap HRMS) method was developed and validated for identification, confirmation and quantitation of illegal adulterated weight-loss drugs in plant dietary supplements. 13 wt-loss drugs were well separated by the gradient elution of 10mmol/L ammonium acetate - 0.05% formic acid H 2 O and acetonitrile at a flow rate of 0.2mL/min within 12min. The MS analysis was operated under the positive ion and in full MS/dd-MS 2 (data-dependent MS 2 ) mode. The full MS scan with resolution at 60 000 FWHM and narrow mass windows at 5ppm acquired data for identification and quantitation, and dd-MS 2 scan with resolution at 15 000 FWHM obtained product ions for confirmation. The method validation showed good linearity with coefficients of determination (r 2 ) higher than 0.9951 for all analytes. Meantime, all the LOD and LLOQ values were in the respective range of 0.3-2 and 1-9ng/g. The accuracy, intra- and inter-day precision were in the ranges of -1.7 to 3.4%, 1.7-5.0% and 1.9-4.4%, respectively. The mean recoveries ranged from 85.4 to 107.1%, while the absolute and relative matrix effect were in the corresponding range of 98.2-108.6% and 2.6-8.7%. Among 120 batches of weight loss plant dietary supplements, sibutramine and fluoxertine or both were positive in 29 samples. In general, LTQ-Orbitrap HRMS technology was a powerful tool for the analysis of illegal ingredients in dietary supplements. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Ground water movements around a repository. Rock mechanics analyses

    International Nuclear Information System (INIS)

    Ratigan, J.L.

    1977-09-01

    The determination and rational assessment of groundwater flow around a repository depends upon the accurate analysis of several interdependent and coupled phenomenological events occuring within the rock mass. In particular, the groundwater flow pathways (joints) are affected by the excavation and thermomechanical stresses developed within the rock mass, and the properties, of the groundwater are altered by the temperature perturbations in the rock mass. The objective of this report is to present the results of the rock mechanics analysis for the repository excavation and the thermally-induced loadings. Qualitative analysis of the significance of the rock mechanics results upon the groundwater flow is provided in this report whenever such an analysis can be performed. Non-linear rock mechanics calculations have been completed for the repository storage tunnels and the global repository domain. The rock mass has been assumed to possess orthoganol joint sets or planes of weakness with finite strength characteristics. In the local analyses of the repository storage tunnels the effects of jointorientation and repository ventilation have been examined. The local analyses indicated that storage room support requirements and regions of strength failure are highly dependent upon joint orientation. The addition of storage tunnel ventilation was noted to reduce regions of strength failure, particularly during the 30 year operational phase of the repository. Examination of the local stresses around the storage tunnels indicated the potential for perturbed hydraulic permeabilities. The permeabilities can be expected to be altered to a greater degree by the stresses resulting from excavation than from stresses which are thermally induced. The thermal loading provided by the instantaneous waste emplacement resulted in stress states and displacements quite similar to those provided by the linear waste emplacement sequence

  1. THERMAL CONDUCTIVITY OF THE POTENTIAL REPOSITORY HORIZON

    Energy Technology Data Exchange (ETDEWEB)

    J.E. BEAN

    2004-09-27

    The primary purpose of this report is to assess the spatial variability and uncertainty of bulk thermal conductivity in the host horizon for the repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). Design plans indicate that approximately 81 percent of the repository will be excavated in the Tptpll, approximately 12 percent in the Tptpmn, and the remainder in the Tptul and Tptpln (BSC 2004 [DIRS 168370]). This report provides three-dimensional geostatistical estimates of the bulk thermal conductivity for the four stratigraphic layers of the repository horizon. The three-dimensional geostatistical estimates of matrix and lithophysal porosity, dry bulk density, and matrix thermal conductivity are also provided. This report provides input to various models and calculations that simulate heat transport through the rock mass. These models include the ''Drift Degradation Analysis, Multiscale Thermohydrologic Model, Ventilation Model and Analysis Report, Igneous Intrusion Impacts on Waste Packages and Waste Forms, Drift-Scale Coupled Processes (DST and TH Seepage) Models'', and ''Drift Scale THM Model''. These models directly or indirectly provide input to the total system performance assessment (TSPA). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large-scale (centimeters-meters) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity.

  2. Monitored Geologic Repository Project Description Document

    International Nuclear Information System (INIS)

    Curry, P. M.

    2001-01-01

    The primary objective of the Monitored Geologic Repository Project Description Document (PDD) is to allocate the functions, requirements, and assumptions to the systems at Level 5 of the Civilian Radioactive Waste Management System (CRWMS) architecture identified in Section 4. It provides traceability of the requirements to those contained in Section 3 of the ''Monitored Geologic Repository Requirements Document'' (MGR RD) (YMP 2000a) and other higher-level requirements documents. In addition, the PDD allocates design related assumptions to work products of non-design organizations. The document provides Monitored Geologic Repository (MGR) technical requirements in support of design and performance assessment in preparing for the Site Recommendation (SR) and License Application (LA) milestones. The technical requirements documented in the PDD are to be captured in the System Description Documents (SDDs) which address each of the systems at Level 5 of the CRWMS architecture. The design engineers obtain the technical requirements from the SDDs and by reference from the SDDs to the PDD. The design organizations and other organizations will obtain design related assumptions directly from the PDD. These organizations may establish additional assumptions for their individual activities, but such assumptions are not to conflict with the assumptions in the PDD. The PDD will serve as the primary link between the technical requirements captured in the SDDs and the design requirements captured in US Department of Energy (DOE) documents. The approved PDD is placed under Level 3 baseline control by the CRWMS Management and Operating Contractor (M and O) and the following portions of the PDD constitute the Technical Design Baseline for the MGR: the design characteristics listed in Table 1-1, the MGR Architecture (Section 4.1), the Technical Requirements (Section 5), and the Controlled Project Assumptions (Section 6)

  3. Monitored Geologic Repository Project Description Document

    International Nuclear Information System (INIS)

    Curry, P.

    2000-01-01

    The primary objective of the Monitored Geologic Repository Project Description Document (PDD) is to allocate the functions, requirements, and assumptions to the systems at Level 5 of the Civilian Radioactive Waste Management System (CRWMS) architecture identified in Section 4. It provides traceability of the requirements to those contained in Section 3 of the ''Monitored Geologic Repository Requirements Document'' (MGR RD) (CRWMS M and O 2000b) and other higher-level requirements documents. In addition, the PDD allocates design related assumptions to work products of non-design organizations. The document provides Monitored Geologic Repository (MGR) engineering design basis in support of design and performance assessment in preparing for the Site Recommendation (SR) and License Application (LA) milestones. The engineering design basis documented in the PDD is to be captured in the System Description Documents (SDDs) which address each of the systems at Level 5 of the CRWMS architecture. The design engineers obtain the engineering design basis from the SDDs and by reference from the SDDs to the PDD. The design organizations and other organizations will obtain design related assumptions directly from the PDD. These organizations may establish additional assumptions for their individual activities, but such assumptions are not to conflict with the assumptions in the PDD. The PDD will serve as the primary link between the engineering design basis captured in the SDDs and the design requirements captured in U.S. Department of Energy (DOE) documents. The approved PDD is placed under Level 3 baseline control by the CRWMS Management and Operating Contractor (M and O) and the following portions of the PDD constitute the Technical Design Baseline for the MGR: the design characteristics listed in Table 2-1, the MGR Architecture (Section 4.1),the Engineering Design Bases (Section 5), and the Controlled Project Assumptions (Section 6)

  4. Rock support for nuclear waste repositories

    International Nuclear Information System (INIS)

    Abramson, L.W.; Schmidt, B.

    1984-01-01

    The design of rock support for underground nuclear waste repositories requires consideration of special construction and operation requirements, and of the adverse environmental conditions in which some of the support is placed. While repository layouts resemble mines, design, construction and operation are subject to quality assurance and public scrutiny similar to what is experienced for nuclear power plants. Exploration, design, construction and operation go through phases of review and licensing by government agencies as repositories evolve. This paper discusses (1) the various stages of repository development; (2) the environment that supports must be designed for; (3) the environmental effects on support materials; and (4) alternative types of repository rock support

  5. The Hidden Risk Decisions in Waste Repository Regulation

    International Nuclear Information System (INIS)

    Frishman, Steve

    2001-01-01

    The move toward risk-informed, performance-based regulation of activities involving radioactive materials is becoming wide spread and broadly applied. While this approach may have some merit in specific applications in which there is a considerable body of experience, its strict application in regulation of geologic repositories for highly radioactive wastes may not be appropriate for this unproven and socially controversial technology. The U.S. Nuclear Regulatory Commission describes risk-informed, performance-based regulation as 'an approach in which risk insights, engineering analysis and judgement (eg. defense in depth), and performance history are used to (1) focus attention on the most important activities, (2) establish objective criteria based upon risk insights for evaluating performance, (3) develop measurable or calculable parameters for monitoring system and licensee performance, and (4) focus on the results as the primary basis for regulatory decision-making.' Both the risk-informed and performance-based elements of the approach are problematic when considering regulation of geologic repositories for highly radioactive wastes - an activity yet to be accomplished by any nation. In investigating potential sites for geologic repositories there will always be residual uncertainty in understanding the natural system and the events and processes that affect it. The more complex the natural system, the greater will be the uncertainty in both the data and the models used to describe the characteristics of the site's natural barriers, and the events and processes that could affect repository waste isolation. The engineered barriers also are subject to uncertainties that are important to the repository system. These uncertainties translate themselves into a range of probabilities that certain events or processes, detrimental to waste isolation, will occur. The uncertainties also translate to a range of consequences and magnitudes of consequences, should the

  6. Safety considerations of disposal of disused sealed sources in Puspokszilagy Repository, Hungary

    International Nuclear Information System (INIS)

    2003-01-01

    The report presents the management of radioactive waste in Hungary Puspokszilagy Repository (RWTDF) including waste acceptance criteria, safety assessments, Action Plan for the safety improvement and present projects. The Puspokszilagy Repository is a typical near-surface repository, sink into the ground 6 m depth. The facility is a shallow land disposal type, appropriated for disposal of short and medium lived LILW, acceptable for temporary storage of long lived LILW. It consists of vaults containing cells for solidified drummed waste, wells for spent sealed sources, work building for treatment and interim storage and office building for environmental measurements. Two safety assessments have been performed in 2000 and 2002. The new safety assessment confirms the main statements of SA 2000, according to which several waste types can cause serious problems in the distant future: Until the finish of passive control the safety of the environment is guaranteed. After that time it is possible to arise events leading to exceeding of dose restricts (more then 10 mSv/yr but less then 100 mSv/yr), because of disposal of long lived radionuclides (mainly C-14,Tc-99, Ra-226, Th-232, U-234) and significant activities of Cs-137 sources.There are uncertainties in radionuclide amounts and distributions, as well as in the physical and chemical characteristics of the wastes that determine radionuclide mobility and toxicity. The recommendations to improve the safety include: Long lived SSRS in the 'B' and 'D' wells should be removed before the closure of repository. Large Cs-137 sources and long lived sources in the 'A' vaults should be recovered (if its feasible); All vaults should be backfilled to provide chemical conditioning; The waste packaged in plastic bags should be repackaged and compacted into drums or containers; The inventory should be revise. Waste acceptance requirements in the future are: The disposal of long lived radionuclides is no permitted. The long lived waste

  7. Nuclide release calculation in the near-field of a reference HLW repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

    2004-01-01

    The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997 in order to develop a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as waste and generic site characteristics in Korea was roughly envisaged in 2003 focusing on the near-field components of the repository system. According to above basic repository concept, which is similar to that of Swedish KBS-3 repository, the spent fuel is first encapsulated in corrosion resistant canisters, even though the material has not yet been determined, and then emplaced into the deposition holes surrounded by high density bentonite clay in tunnels constructed at a depth of about 500 m in a stable plutonic rock body. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near-field components of the repository, even though enough information has not been available that much yet, but also to show a methodology by which a generic safety assessment could be performed for further development of Korea reference repository concept, nuclide release calculation study strongly seems to be necessary

  8. Long-term environmental impacts of geologic repositories

    International Nuclear Information System (INIS)

    Pigford, T.H.

    1983-05-01

    This paper summarizes a study of the long-term environmental impacts of geologic repositories for radioactive wastes. Conceptual repositories in basalt, granite, salt, and tuff were considered. Site-specific hydrological and geochemical parameters were used wherever possible, supplemented with generic parameters when necessary. Radiation doses to future maximally exposed individuals who use the contaminated groundwater and surface water were calculated and compared with a performance criterion of 10 -4 Sv/yr for radiation exposures from probable events. The major contributors to geologic isolation are the absence of groundwater if the repository is in natural salt, the slow dissolution of key radioelements as limited by solubility and by diffusion and convection in groundwater, long water travel times from the waste to the environment, and sorption retardation in the media surrounding the repository. In addition, dilution by surface water can considerably reduce the radiation exposures that result from the small fraction of the waste radioactivity that may ultimately reach the environment. Estimates of environmental impacts are made both for unreprocessed spent fuel and for reprocessing wastes. Accelerated dissolution of waste exposed to groundwater during the period of repository heating is also considered. This study of environmental impacts is a portion of a more comprehensive study of geologic waste disposal carried out by the Waste Isolation System Panel of the US National Research Council

  9. Reference design description for a geologic repository: Revision 01

    International Nuclear Information System (INIS)

    1997-09-01

    This document describes the current design expectations for a potential geologic repository that could be located at Yucca Mountain in Nevada. This Reference Design Description (RDD) looks at the surface and subsurface repository and disposal container design. Additionally, it reviews the expected long-term performance of the potential repository. In accordance with current legislation, the reference design for the potential repository does not include an interim storage option. The reference design presented allows the disposal of highly radioactive material received from government-owned spent fuel custodian sites; produces high-level waste sites, and commercial spent fuel sites. All design elements meet current federal, state, and local regulations governing the disposal of high-level radioactive waste and protection of the public and the environment. Due to the complex nature of developing a repository, the design will be created in three phases to support Viability Assessment, License Application, and construction. This document presents the current reference design. It will be updated periodically as the design progresses. Some of the details presented here may change significantly as more cost-effective solutions, technical advancements, or changes to requirements are identified

  10. Evaluation of Nuclide Release Scenarios for a Hypothetical LILW Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Jeong, Jong Tae

    2010-11-01

    A program for the safety assessment and performance evaluation of a low- and intermediate-level radioactive waste (LILW) repository system has been developed. Utilizing GoldSim (GoldSim, 2006), the program evaluates nuclide release and transport into the geosphere and biosphere under various disruptive natural and manmade events and scenarios that can occur after a waste package failure. We envisaged and illustrated these events and scenarios as occurring after the closure of a hypothetical LILW repository, and they included the degradation of various manmade barriers, pumping well drilling, and natural disruptions such as the sudden formation of a preferential flow pathway in the far-field area of the repository. Possible enhancement of nuclide transport facilitated by colloids or chelating agents is also dealt with. We used the newly-developed GoldSim template program, which is capable of various nuclide release scenarios and is greatly suited for simulating a potential repository given the geological circumstances in Korea, to create the detailed source term and near-field release scheme, various nuclide transport modes in the far-field geosphere area, and the biosphere transfer. Even though all parameter values applied to the hypothetical repository were assumed, the illustrative results, particularly the probabilistic calculations and sensitivity studies, may be informative under various scenarios

  11. Reference design description for a geologic repository. Revision 02

    International Nuclear Information System (INIS)

    1999-01-01

    This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada. It describes the proposed design for a surface facility, subsurface repository, and waste packaging; it also presents the current design of the key engineering systems for the final four phases: operations, monitoring, closure, and postclosure. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. In accordance with current law, this design does not include an interim storage option. This document has six major sections. Section 1 describes the physical layout of the proposed repository. The second section describes the 4-phase evolution of the development of the proposed repository. Section 3 describes the reception of waste from offsite locations. The fourth section details the various systems that will package the waste and move it below ground as well as safety monitoring and closure. Section 5 describes the systems (both physical and analytical) that ensure continued safety after closure. The final section offers design options that may be adopted to increase the margin of safety

  12. Implementing digital preservation in repositories: Knowledge and practices

    Directory of Open Access Journals (Sweden)

    Caterina Groposo Pavão

    2016-09-01

    Full Text Available Digital preservation has to be undertaken by institutional repositories, which are responsible for the preservation of the scientific output from academic institutions. However, due to the constant evolution of the field, to gain domain knowledge and recognise best practices is a complex task for people responsible for digital preservation in those institutions. Digital preservation research, practices and solutions address specific problems, such as formats, curation, reference models, authenticity, policies and preservation plans, tools, etc., while stakeholders need an integrated, contextualized and applicable overview. This paper focuses on the implementation of digital preservation in repositories, from the perspective of the team responsible for the project, regarding the necessary knowledge and best practices. Initially, it defines and contextualizes digital preservation repositories. The following section presents a conceptual model of digital preservation, synthesized from conceptual models developed in influential projects in the field, which allows us to identify the domain knowledge in digital preservation. Finally, aspects represented in the model are discussed in the light of the performance of teams implementing digital preservation repositories. It provides recommendations, guides and examples that may be useful for the implementation of digital preservation. It points to the need to strengthen the relationship between domain knowledge in digital preservation repositories with practices developed in numerous projects developed worldwide.

  13. PA/SA for Slovenian LILW repository

    International Nuclear Information System (INIS)

    Zeleznik, N.; Mele, I.

    1999-01-01

    The RAO Agency started with a new site selection procedure in 1996. As part of the preparational work for the new disposal facility, tools for assessment of the specific disposal concept influence on the environment and human has to be developed. Therefore the Slovenian assessment team that has been organized, joined the IAEAs ISAM programme, in which different approaches to performance and safety assessment were applied to safety cases. As part of the ISAM individual (national) safety cases. The RAO Agency, together with other Slovenian Inst.ions, performed the preliminary performance assessment of the Slovenian LILW repository for generic site location. The method and the results of the safety case are presented in this paper.(author)

  14. NRC overview: Repository QA

    International Nuclear Information System (INIS)

    Kennedy, J.E.

    1988-01-01

    The US Department of Energy (DOE) is on the threshold of an extensive program for characterizing Yucca Mountain in Nevada to determine if it is a suitable site for the permanent disposal of high-level nuclear waste. Earlier this year, the DOE published the Consultation Draft Site Characterization Plan for the Nevada site, which describes in some detail the studies that need to be performed to determine if the site is acceptable. In the near future, the final site characterization plan (SCP) is expected to be issued and large-scale site characterization activities to begin. The data and analyses that will result from the execution of that plan are expected to be the primary basis for the license application to the US Nuclear Regulatory Commission (NRC). Because of the importance of these data and analyses in the assessment of the suitability of the site and in the demonstration of that suitability in the NRC licensing process, the NRC requires in 10CFR60 that site characterization be performed under a quality assurance (QA) program. The QA program is designed to provide confidence that data are valid, retrievable, and reproducible. The documentation produced by the program will form an important part of the record on which the suitability of the site is judged in licensing. In addition, because the NRC staff can review only a selected portion of the data collected, the staff will need to rely on the system of controls in the DOE QA program

  15. Determination of Four Major Saponins in Skin and Endosperm of Seeds of Horse Chestnut (Aesculus Hippocastanum L.) Using High Performance Liquid Chromatography with Positive Confirmation by Thin Layer Chromatography.

    Science.gov (United States)

    Abudayeh, Zead Helmi Mahmoud; Al Azzam, Khaldun Mohammad; Naddaf, Ahmad; Karpiuk, Uliana Vladimirovna; Kislichenko, Viktoria Sergeevna

    2015-11-01

    To separate and quantify four major saponins in the extracts of the skin and the endosperm of seeds of horse chestnut (Aesculus hippocastanum L.) using ultrasonic solvent extraction followed by a high performance liquid chromatography-diode array detector (HPLC-DAD) with positive confirmation by thin layer chromatography (TLC). The saponins: escin Ia, escin Ib, isoescin Ia and isoescin Ib were extracted using ultrasonic extraction method. The optimized extraction conditions were: 70% methanol as extraction solvent, 80 °C as extraction temperature, and the extraction time was achieved in 4 hours. The HPLC conditions used: Zorbax SB-ODS-(150 mm × 2.1 mm, 3 μm) column, acetonitrile and 0.10% phosphoric acid solution (39:61 v/v) as mobile phase, flow rate was 0.5 mL min(-1) at 210 nm and 230 nm detection. The injection volume was 10 μL, and the separation was carried out isothermally at 30 °C in a heated chamber. The results indicated that the developed HPLC method is simple, sensitive and reliable. Moreover, the content of escins in seeds decreased by more than 30% in endosperm and by more than 40% in skin upon storage for two years. This assay can be readily utilized as a quality control method for horse chestnut and other related medicinal plants.

  16. The Proposed Yucca Mountain Repository From A Corrosion Perspective

    International Nuclear Information System (INIS)

    J.H. Payer

    2005-01-01

    Corrosion is a primary determinant of waste package performance at the proposed Yucca Mountain Repository and will control the delay time for radionuclide transport from the waste package. Corrosion is the most probable and most likely degradation process that will determine when packages will be penetrated and the shape size and distribution of those penetrations. The general issues in corrosion science, materials science and electrochemistry are well defined, and the knowledge base is substantial for understanding corrosion processes. In this paper, the Yucca Mountain Repository is viewed from a corrosion perspective

  17. SCALING ANALYSIS OF REPOSITORY HEAT LOAD FOR REDUCED DIMENSIONALITY MODELS

    International Nuclear Information System (INIS)

    MICHAEL T. ITAMUA AND CLIFFORD K. HO

    1998-01-01

    The thermal energy released from the waste packages emplaced in the potential Yucca Mountain repository is expected to result in changes in the repository temperature, relative humidity, air mass fraction, gas flow rates, and other parameters that are important input into the models used to calculate the performance of the engineered system components. In particular, the waste package degradation models require input from thermal-hydrologic models that have higher resolution than those currently used to simulate the T/H responses at the mountain-scale. Therefore, a combination of mountain- and drift-scale T/H models is being used to generate the drift thermal-hydrologic environment

  18. Software aspects of the Geant4 validation repository

    Science.gov (United States)

    Dotti, Andrea; Wenzel, Hans; Elvira, Daniel; Genser, Krzysztof; Yarba, Julia; Carminati, Federico; Folger, Gunter; Konstantinov, Dmitri; Pokorski, Witold; Ribon, Alberto

    2017-10-01

    The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientific Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER is easily accessible via a web application. In addition, a web service allows for programmatic access to the repository to extract records in JSON or XML exchange formats. In this article, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

  19. Impact of partitioning and transmutation on repository design

    International Nuclear Information System (INIS)

    Carter, D. 'Buzz' Savage

    2004-01-01

    The U.S. Department of Energy's Advanced Fuel Cycle Initiative (AFCI) program is investigating spent nuclear fuel treatment technologies that have the potential to improve the performance of the proposed geologic repository at Yucca Mountain. Separating actinides and selected fission products from spent fuel, storing some of them as low level waste and transmuting them in thermal and/or fast reactors has the potential to reduce the volume, short and long-term heat load and radiotoxicity of the high level waste destined for the repository, effectively increasing its capacity by a factor of 50 or more above the current legislative limit. (author)

  20. Software Aspects of the Geant4 Validation Repository

    CERN Document Server

    Dotti, Andrea; Elvira, Daniel; Genser, Krzysztof; Yarba, Julia; Carminati, Federico; Folger, Gunter; Konstantinov, Dmitri; Pokorski, Witold; Ribon, Alberto

    2016-01-01

    The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientic Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER is easily accessible via a web application. In addition, a web service allows for programmatic access to the repository to extract records in JSON or XML exchange formats. In this article, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

  1. University digital repositories and authors.

    Directory of Open Access Journals (Sweden)

    Alice Keefer

    2008-02-01

    Full Text Available The Open Access movement offers two strategies for making scientific information available without economic, technical or legal obstacles: the publication of articles in OA journals and the deposit by authors of their Works in stable institutional or discipline-based repositories. This article explores the implementation of the second “route” on the part of authors, because it is the strategy that offers the greatest possibility of attaining OA in the short term. However, it does require repositories to exert great effort in informing the authors of the advantages of self-archiving and of the procedures for depositing their work and, even helping them to do so – through services and promotional activities.

  2. Thermal dimensioning of spent fuel repository

    International Nuclear Information System (INIS)

    Ikonen, K.

    2009-09-01

    This report contains the temperature dimensioning of the KBS-3V type nuclear fuel repository in Olkiluoto for the BWR, VVER and EPR fuel canisters, which are disposed at vertical position in the horizontal tunnels in a rectangular geometry according to the preliminary Posiva plan. This report concerns only the temperature dimensioning of the repository and does not take into account the possible restrictions caused by the stresses induced in the rock. The maximum temperature on the canister-bentonite interface is limited to the design temperature of +100 deg C. However, due to uncertainties in thermal analysis parameters (like scattering in rock conductivity or in predicted decay power) the allowable calculated maximum canister temperature is set to 90 deg C causing a safety margin of 10 deg C. The allowable temperature is controlled by adjusting the space between adjacent canisters, adjacent tunnels and the pre-cooling time affecting on power of the canisters. The temperature of canister surfaces can be determined by superposing analytic line heat source models much more efficiently than by numerical analysis, if the analytic model is first calibrated by numerical analysis (by control volume method). This was done by comparing the surface temperatures of a single canister calculated numerically and analytically. For the Olkiluoto repository of one panel having 900 canisters of BWR, VVER and EPR spent fuel was analyzed. The analyses were performed with an initial canister power of 1 700 W, 1 370 W and 1 830 W, respectively. These decay heats are obtained when the pre-cooling times of the fuels are 32.9, 29.6 and 50.3 years (the burn-up values 40, 40 and 50 MWd/kgU, respectively). The analyses gave as a result the canister spacing (6.0-10.8 m), when the tunnel spacing was 25 m, 30 m or 40 m. On the edge areas of the panel with constant canister spacing the temperatures of the canisters are lower than in the middle area of the repository. Thus it is possible to pack

  3. Some reflections on human intrusion into a nuclear waste repository

    International Nuclear Information System (INIS)

    Westerlind, M.

    2002-01-01

    This paper summarises some of the Swedish nuclear regulators' requirements and views related to intrusion into a repository for spent nuclear fuel, in the post-closure phase. The focus is however on experiences from the interaction with various stakeholders in the Swedish process for siting a repository. It is recognised that intrusion is not a major concern but that it is regularly raised in the debate, often in connection with issues related to retrievability. It is pointed out that more attention should be paid to the repository performance after an intrusion event, both in safety assessments and in communication with stakeholders, and not only address the immediate impacts to intruders. It is believed that international co-operation would be useful for developing methodologies for defining intrusion scenarios. (author)

  4. Engineered barrier development for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    The BWIP Engineered Barrier Program has been developed to provide an integrated approach to the development of site-specific Engineered Barrier assemblages for a repository located in basalt. The goal of this program is to specify engineered and natural barriers which will ensure that nuclear and non-radioactive hazardous materials emplaced in a repository in basalt do not exceed acceptable rates of release to the biosphere. A wide range of analytical and experimental activities related to the basalt repository environment, waste package environment, waste/barrier/rock interactions, and barrier performance assessment provide the basis for selection of systems capable of meeting licensing requirements. Work has concentrated on specifying and testing natural and man-made materials which can be used to plug boreholes in basalt and which can be used as multiple barriers to surround nuclear waste forms and containers. The Engineered Barriers Program is divided into two major activities: multiple barrier studies and borehole plugging. 8 figures, 4 tables

  5. Stability of underground excavations in a repository system

    International Nuclear Information System (INIS)

    Calash, A.Y.; Greer, J.C.; Andrea, S.J.; Chowdhury, A.H.; Nguyen, V.V.

    1988-01-01

    The DOE is investigating the feasibility of constructing a deep geologic repository at the Hanford Site, Washington, for the permanent disposal of nuclear waste. The underground openings associated with the repository design include shafts, tunnels, emplacement rooms and boreholes. The stability of these underground openings, the extent and characteristics of the disturbed zones due to excavation, and their effects on groundwater flow path and travel time have a primary influence on the performance assessment of the Hanford Site as a nuclear waste repository. This study is being done in accordance with the requirements of the NRC. Results of structural analyses of shafts and tunnels under in situ stresses and/or medium weight are presented in this paper. Four different analyses were carried out to analyze the shaft: a plane strain model, axisymmetric model, 3-D model of a single material medium, and 3-D model of a three material medium

  6. Opinion dynamics with confirmation bias.

    Directory of Open Access Journals (Sweden)

    Armen E Allahverdyan

    Full Text Available Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science.We formulate a (non-Bayesian model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect-when consecutively exposed to two opinions, the preference is given to the last opinion (recency or the first opinion (primacy -and relates recency to confirmation bias. Finally, we study the model in the case of repeated persuasion and analyze its convergence properties.The standard Bayesian approach to probabilistic opinion revision is inadequate for describing the observed phenomenology of persuasion process. The simple non-Bayesian model proposed here does agree with this phenomenology and is capable of reproducing a spectrum of effects observed in psychology: primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point out several limitations of the model that should motivate its future development.

  7. Integrating repositories with fuel cycles: The airport authority model

    International Nuclear Information System (INIS)

    Forsberg, C.

    2012-01-01

    The organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of a geological repository site with a single owner, a single function (disposal), and no other facilities on site. Recent studies indicate large economic, safety, repository performance, nonproliferation, and institutional incentives to collocate and integrate all back-end facilities. Site functions could include geological disposal of spent nuclear fuel (SNF) with the option for future retrievability, disposal of other wastes, reprocessing with fuel fabrication, radioisotope production, other facilities that generate significant radioactive wastes, SNF inspection (navy and commercial), and related services such as SNF safeguards equipment testing and training. This implies a site with multiple facilities with different owners sharing some facilities and using common facilities - the repository and SNF receiving. This requires a different repository site institutional structure. We propose development of repository site authorities modeled after airport authorities. Airport authorities manage airports with government-owned runways, collocated or shared public and private airline terminals, commercial and federal military facilities, aircraft maintenance bases, and related operations - all enabled and benefiting the high-value runway asset and access to it via taxi ways. With a repository site authority the high value asset is the repository. The SNF and HLW receiving and storage facilities (equivalent to the airport terminal) serve the repository, any future reprocessing plants, and others with needs for access to SNF and other wastes. Non-public special-built roadways and on-site rail lines (equivalent to taxi ways) connect facilities. Airport authorities are typically chartered by state governments and managed by commissions with members

  8. Integrating repositories with fuel cycles: The airport authority model

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C. [Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)

    2012-07-01

    The organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of a geological repository site with a single owner, a single function (disposal), and no other facilities on site. Recent studies indicate large economic, safety, repository performance, nonproliferation, and institutional incentives to collocate and integrate all back-end facilities. Site functions could include geological disposal of spent nuclear fuel (SNF) with the option for future retrievability, disposal of other wastes, reprocessing with fuel fabrication, radioisotope production, other facilities that generate significant radioactive wastes, SNF inspection (navy and commercial), and related services such as SNF safeguards equipment testing and training. This implies a site with multiple facilities with different owners sharing some facilities and using common facilities - the repository and SNF receiving. This requires a different repository site institutional structure. We propose development of repository site authorities modeled after airport authorities. Airport authorities manage airports with government-owned runways, collocated or shared public and private airline terminals, commercial and federal military facilities, aircraft maintenance bases, and related operations - all enabled and benefiting the high-value runway asset and access to it via taxi ways. With a repository site authority the high value asset is the repository. The SNF and HLW receiving and storage facilities (equivalent to the airport terminal) serve the repository, any future reprocessing plants, and others with needs for access to SNF and other wastes. Non-public special-built roadways and on-site rail lines (equivalent to taxi ways) connect facilities. Airport authorities are typically chartered by state governments and managed by commissions with members

  9. Environmentally assisted cracking mechanisms in repository environments

    International Nuclear Information System (INIS)

    Mills, W.J.

    1987-02-01

    This paper assesses how environmentally assisted cracking (EAC) mechanisms in candidate container materials can be identified to enhance the accuracy of long-term projections of performance in the repository. In low and intermediate strength steels, the role of the two principal mechanisms, slip dissolution/film rupture (SD/FR) and hydrogen embrittlement (HE), is a very complex and controversial issue. No unanimity exists concerning the operative cracking mechanisms, and there is no unique or rigorous approach that would be persuasive in selecting an appropriate model. Both of the proposed mechanisms have common rate controlling processes such as surface adsorption rate, passivation rate, and oxidation rupture rate, which makes it difficult to identify the operative mechanism. Development of a quantitative model for predicting environmental effects for low-carbon steels in repository environments would provide a theoretical basis for assuring the long-term structural integrity of waste-package containment. To date, only one quantitative model has been developed. The agreement between predicted and observed behavior suggests that SD/FR processes control the environmental acceleration in crack growth rates for this class of materials. Deviations from predicted behavior due to HE effects should be uncovered experimentally. 59 refs., 4 figs., 4 tabs

  10. Salt Repository Project transportation program plan

    International Nuclear Information System (INIS)

    Fisher, R.L.; Greenberg, A.H.; Anderson, T.L.; Yates, K.R.

    1987-01-01

    The Salt Repository Project (SRP) has the responsibility to develop a comprehensive transportation program plan (TrPP) that treats the transportation of workers, supplies, and high-level radioactive waste to the site and the transportation of salt, low-level, and transuranic wastes from the site. The TrPP has developed a systematic approach to transportation which is directed towards satisfying statutes, regulations, and directives and is guided by a hierarchy of specific functional requirements, strategies, plans, and reports. The TrPP identifies and develops the planning process for transportation-related studies and provides guidance to staff in performing and documenting these activities. The TrPP also includes an explanation of the responsibilities of the organizational elements involved in these transportation studies. Several of the report chapters relate to identifying routes for transporting nuclear waste to the site. These include a chapter on identifying an access corridor for a new rail route leading to the site, identifying and evaluating emergency-response preparedness capabilities along candidate routes in the state, and identifying alternative routes from the state border, ports, or in-state reactors to the site. The TrPP also includes plans for identifying salt disposal routes and a discussion of repository/transportation interface requirements. 89 refs., 6 figs

  11. Repository design sensitivity study: Engineering study report

    International Nuclear Information System (INIS)

    1987-01-01

    A preliminary sensitivity study of the salt repository design has been performed to identify critical site and design parameters to help guide future site characterization and design optimization activities. The study considered the SCP-conceptual design at the Deaf Smith County site in Texas with the horizontal waste package emplacement mode as the base case. Relative to this base case, parameter variations were compared. Limited studies were performed which considered the vertical emplacement mode geometry. The report presents the reference data base and design parameters on which the study was based (including the range of parameters that might be expected). Detailed descriptions of the numerical modeling methods and assumptions are included for the thermal, thermomechanical and hydrogeological analyses. The impacts of parameter variations on the sensitivity of the rock mass response are discussed. Recommendations are provided to help guide site characterization activities and advanced conceptual design optimization activities. 47 refs., 119 refs., 22 tabs

  12. Simultaneous determination and identity confirmation of thiodicarb and its degradation product methomyl in animal-derived foodstuffs using high-performance liquid chromatography with fluorescence detection and tandem mass spectrometry.

    Science.gov (United States)

    Rahman, Md Musfiqur; Abd El-Aty, A M; Kim, Sung-Woo; Lee, Young-Jun; Na, Tae-Woong; Park, Joon-Seong; Shin, Ho-Chul; Shim, Jae-Han

    2017-01-01

    A high-performance liquid chromatography-fluorescence detection method was developed for the simultaneous determination of thiodicarb and its degradation product methomyl in animal-derived food products, including chicken muscle, beef, pork, table eggs, and milk. Thiodicarb is known to degrade during analysis; therefore, a thorough investigation was carried out, revealing that thiodicarb degrades to methomyl immediately after spiking into a matrix of animal-derived food products. Consequently, thiodicarb was determined as the sum of the parent compound and methomyl. Samples were extracted with acetonitrile and sodium salts, and purified using solid-phase extraction (SPE). The limits of detection (LODs) and quantification (LOQs) were 0.0013 and 0.004mg/kg, respectively, for both analytes in various matrices. Seven-point external calibration curves were obtained, and they showed excellent linearity with determination coefficients (R 2 )≥0.999 for all tested matrices. The method was validated at three fortification levels (LOQ, LOQ×2, and LOQ×10) in triplicate with average recoveries ranging from 84.24 to 112.8% (for methomyl) and relative standard deviations (RSDs)≤6.5% in all matrices. The converted recoveries of thiodicarb in various matrices ranged from 74.80 to 107.80% with RSDs≤4.5%. The identities of both compounds in standard solutions and for recovery were confirmed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The developed method was further validated by accurate reproduction at another laboratory. Finally, the method was applied to market samples collected from different areas (and, in the case of milk, different brands), and none of the samples tested positive for thiodicarb or methomyl. In conclusion, the developed method can be successfully applied for a single-run analysis of thiodicarb and methomyl in livestock products. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Characteristics and behaviour of C-14, Cl-36, Pu-239 and Tc-99 in the Biosphere in the context of performance assessments of geological repositories for high-level radioactive wastes

    International Nuclear Information System (INIS)

    Aguero, A.; Perez-Sanchez, D.; Trueba, C.; Moraleda, M.

    2006-01-01

    The evaluation of the safety of high-level radioactive wastes repositories is a requisite of the radioactive waste management policy. Criteria for the safety of those facilities [IAEA, 1995] require protection of the population and the environment over a time scale appropriate to the characteristics of the disposed wastes. In order to demonstrate compliance with the relevant principles and regulations, there is the requirement for an analysis and quantification of system behavior including the transport of radionuclides from the facility to the biosphere, their transport in the biosphere and the resulting exposure of humans, including the evaluation of radiation doses from both external and internal exposure. Realistic models to simulate the transport of radionuclides in the environment are essential. The biosphere model needs to represent the transport and accumulation of radionuclides in the different media, including characterization of the pathways through which the contaminants give rise to exposure of humans. Such modeling needs to take account of the specific characteristics of the radionuclides involved, which have different physical, chemical and biological characteristics and behaviors and could require conceptually different models to predict their transport through, and distribution in, the relevant environmental media. Key radionuclides that have been shown to contribute most to the doses estimated in high-level radioactive waste disposal performance assessments were identified in [Watkins and Smith, 1999]. The important factors that determine whether a radionuclide will be a key contributor to dose are: its total inventory, half-life, solubility and adsorption potential, and biosphere flux-to-dose conversion factor. Only a limited number of radionuclides are likely to be important for the groundwater release and transport pathway from the point of view of their contribution to annual individual dose to humans: ''237Np (and its progeny), ''129I, ''99Tc

  14. Technical conservatism in the design and analysis of a nuclear-waste repository in basalt

    International Nuclear Information System (INIS)

    Jones, K.A.

    1982-01-01

    The US Department of Energy's National Waste Terminal Storage Program has adopted a policy of technical conservatism to guide the design and analysis of geologic disposal systems for commercial high-level radioactive waste. Technical conservatism serves as the programmatic philosophy for managing uncertainty in the performance of the disposal system. The implementation of technical conservatism as applied to a nuclear waste repository in basalt is discussed. Preliminary assessments of the performance of the waste package, repository, and site subsystems are compared to key proposed regulatory criteria. The comparison shows that there are substantial safety margins in the predicted performance of the nuclear waste repository in basalt

  15. A reversed phase high performance liquid chromatography method for the determination of fumonisins B1 and B2 in food and feed using monolithic column and positive confirmation by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Khayoon, Wejdan Shakir; Saad, Bahruddin; Salleh, Baharuddin; Ismail, Nor Azliza; Abdul Manaf, Normaliza Hj; Abdul Latiff, Aishah

    2010-10-29

    The development of a reversed phase high performance liquid chromatography fluorescence method for the determination of the mycotoxins fumonisin B(1) and fumonisin B(2) by using silica-based monolithic column is described. The samples were first extracted using acetonitrile:water (50:50, v/v) and purified by using a C(18) solid phase extraction-based clean-up column. Then, pre-column derivatization for the analyte using ortho-phthaldialdehyde in the presence of 2-mercaptoethanol was carried out. The developed method involved optimization of mobile phase composition using methanol and phosphate buffer, injection volume, temperature and flow rate. The liquid chromatographic separation was performed using a reversed phase Chromolith(®) RP-18e column (100 mm × 4.6 mm) at 30 °C and eluted with a mobile phase of a mixture of methanol and phosphate buffer pH 3.35 (78:22, v/v) at a flow rate of 1.0 mL min(-1). The fumonisins separation was achieved in about 4 min, compared to approximately 20 min by using a C(18) particle-packed column. The fluorescence excitation and emission were at 335 nm and 440 nm, respectively. The limits of detections were 0.01-0.04 μg g(-1) fumonisin B(1) and fumonisin B(2), respectively. Good recoveries were found for spiked samples (0.1, 0.5, 1.5 μg g(-1) fumonisins B(1) and B(2)), ranging from 84.0 to 106.0% for fumonisin B(1) and from 81.0 to 103.0% for fumonisin B(2). Fifty-three samples were analyzed including 39 food and feeds and 14 inoculated corn and rice. Results show that 12.8% of the food and feed samples were contaminated with fumonisin B(1) (range, 0.01-0.51 μg g(-1)) and fumonisin B(2) (0.05 μg g(-1)). The total fumonisins in these samples however, do not exceed the legal limits established by the European Union of 0.8 μg g(-1). Of the 14 inoculated samples, 57.1% contained fumonisin B(1) (0.16-41.0 μg g(-1)) and fumonisin B(2) (range, 0.22-50.0 μg g(-1)). Positive confirmation of selected samples was carried out using

  16. Corrosion of the copper canister in the repository environment

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Eriksson, Sture [Studsvik Material AB, Nykoeping (Sweden)

    1999-12-01

    The present report accounts for studies on copper corrosion performed at Studsvik Material AB during 1997-1999 on commission by SKI. The work has been focused on localised corrosion and electrochemistry of copper in the repository environment. The current theory of localised copper corrosion is not consistent with recent practical experiences. It is therefore desired to complete and develop the theory based on knowledge about the repository environment and evaluations of previous as well as recent experimental and field results. The work has therefore comprised a thorough compilation and up-date of literature on copper corrosion and on the repository environment. A selection of a 'working environment', defining the chemical parameters and their ranges of variation has been made and is used as a fundament for the experimental part of the work. Experiments have then been performed on the long-range electrochemical behaviour of copper in selected environments simulating the repository. Another part of the work has been to further develop knowledge about the thermodynamic limits for corrosion in the repository environment. Some of the thermodynamic work is integrated here. Especially thermodynamics for the system Cu-Cl-H-O up to 150 deg C and high chloride concentrations are outlined. However, there is also a rough overview of the whole system Cu-Fe-Cl-S-C-H-O as a fundament for the discussion. Data are normally accounted as Pourbaix diagrams. Some of the conclusions are that general corrosion on copper will probably not be of significant importance in the repository as far as transportation rates are low. However, if such rates were high, general corrosion could be disastrous, as there is no passivation of copper in the highly saline environment. The claim on knowledge of different kinds of localised corrosion and pitting is high, as pitting damages can shorten the lifetime of a canister dramatically. Normal pitting can happen in oxidising environment, but

  17. Corrosion of the copper canister in the repository environment

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Eriksson, Sture

    1999-12-01

    The present report accounts for studies on copper corrosion performed at Studsvik Material AB during 1997-1999 on commission by SKI. The work has been focused on localised corrosion and electrochemistry of copper in the repository environment. The current theory of localised copper corrosion is not consistent with recent practical experiences. It is therefore desired to complete and develop the theory based on knowledge about the repository environment and evaluations of previous as well as recent experimental and field results. The work has therefore comprised a thorough compilation and up-date of literature on copper corrosion and on the repository environment. A selection of a 'working environment', defining the chemical parameters and their ranges of variation has been made and is used as a fundament for the experimental part of the work. Experiments have then been performed on the long-range electrochemical behaviour of copper in selected environments simulating the repository. Another part of the work has been to further develop knowledge about the thermodynamic limits for corrosion in the repository environment. Some of the thermodynamic work is integrated here. Especially thermodynamics for the system Cu-Cl-H-O up to 150 deg C and high chloride concentrations are outlined. However, there is also a rough overview of the whole system Cu-Fe-Cl-S-C-H-O as a fundament for the discussion. Data are normally accounted as Pourbaix diagrams. Some of the conclusions are that general corrosion on copper will probably not be of significant importance in the repository as far as transportation rates are low. However, if such rates were high, general corrosion could be disastrous, as there is no passivation of copper in the highly saline environment. The claim on knowledge of different kinds of localised corrosion and pitting is high, as pitting damages can shorten the lifetime of a canister dramatically. Normal pitting can happen in oxidising environment, but there is

  18. Comparison of potential radiological consequences from a spent-fuel repository and natural uranium deposits

    International Nuclear Information System (INIS)

    Wick, O.J.; Cloninger, M.O.

    1980-09-01

    A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore deposits and, in some cases, present less radiological hazard than their natural counterparts. On the basis of the first comparison, placing spent fuel in a deep geologic repository apparently reduces the hazard from natural radioactive materials occurring in the earth's crust by locating the waste in impermeable strata without access to oxidizing conditions. On the basis of the second comparison, a repository constructed within reasonable constraints presents no greater hazard than a large ore deposit. It is recommended that if the naturally radioactive environment is to be used as a basis for a criterion regarding repositories, then this criterion should be carefully constructed. The criterion should be based on the radiological quality of the waters in the immediate region of a specific repository, and it should be in terms of an acceptable potential increase in the radiological content of those waters due to the existence of the repository

  19. An evaluation of repository-induced disturbances for a KBS-3 type repository

    Energy Technology Data Exchange (ETDEWEB)

    Savage, D.; McLeod, R.; McEwen, T. [QuantiSci, Melton Mowbray (United Kingdom)

    1998-03-01

    This report considers the potential physical and chemical perturbations caused by the excavation, operation and backfilling and sealing of a KBS-3 type repository for spent fuel in Sweden. Parts of the underground excavations are likely to remain open to the atmosphere for up to several decades. Time-dependent changes to the chemical environment and the properties of the geological formation will be occurring as well as the initial disturbance of construction and subsequent changes after backfilling. In addition, this report also discusses issues that arise from the co-disposal of spent fuel and intermediate level waste. The processes which are likely to act during each stage of a repository from construction through to backfilling and sealing have been reviewed and the degree to which these processes are understood and represented within the performance assessment is discussed. The areas of particular interest are: The coupling of thermal, hydrogeological and mechanical processes with particular reference to the development of the near-field; Understanding the transient process of re-saturation with particular reference to the buffer material surrounding the waste canisters, including chemical changes to the material; The impact of accidental events during the construction and operational phases of work and their possible consequence on the long term performance of the repository; Chemical issues relating to the co-disposal of spent fuel and intermediate level wastes within a single facility. When consideration of transient processes and coupling is discussed, it is apparent that numerical tools and a complete understanding to provide quantitative information is lacking. The importance of the engineered barrier system within the performance assessment for spent fuel disposal is recognised and the emphasis is placed on the understanding of the coupled processes in the evolution in the near-field of the geosphere 45 refs, 4 fig, 2 tabs

  20. An evaluation of repository-induced disturbances for a KBS-3 type repository

    International Nuclear Information System (INIS)

    Savage, D.; McLeod, R.; McEwen, T.

    1998-03-01

    This report considers the potential physical and chemical perturbations caused by the excavation, operation and backfilling and sealing of a KBS-3 type repository for spent fuel in Sweden. Parts of the underground excavations are likely to remain open to the atmosphere for up to several decades. Time-dependent changes to the chemical environment and the properties of the geological formation will be occurring as well as the initial disturbance of construction and subsequent changes after backfilling. In addition, this report also discusses issues that arise from the co-disposal of spent fuel and intermediate level waste. The processes which are likely to act during each stage of a repository from construction through to backfilling and sealing have been reviewed and the degree to which these processes are understood and represented within the performance assessment is discussed. The areas of particular interest are: The coupling of thermal, hydrogeological and mechanical processes with particular reference to the development of the near-field; Understanding the transient process of re-saturation with particular reference to the buffer material surrounding the waste canisters, including chemical changes to the material; The impact of accidental events during the construction and operational phases of work and their possible consequence on the long term performance of the repository; Chemical issues relating to the co-disposal of spent fuel and intermediate level wastes within a single facility. When consideration of transient processes and coupling is discussed, it is apparent that numerical tools and a complete understanding to provide quantitative information is lacking. The importance of the engineered barrier system within the performance assessment for spent fuel disposal is recognised and the emphasis is placed on the understanding of the coupled processes in the evolution in the near-field of the geosphere

  1. Fostering New Roles for Librarians: Skills Set for Repository Managers — Results of a Survey in Italy

    Directory of Open Access Journals (Sweden)

    Maria Cassella

    2012-04-01

    Full Text Available The open access movement in scholarly communication has grown considerably over the last ten years and it has driven an increase in the number of institutional repositories (IRs. New professional roles and skills had to be developed to secure effective IR management. Collection developmente expertise and metadata curation are regarded as strategic roles for repositories and therefore it is only logical for the library and information community to take on the responsibility for managing these digital archives. However, it has become clear that traditional librarian skills do not suffice anymore to run successful repositories. A richer set of skills is needed, including management and communication skills, technical skills, and expertise with regard to access rights and preservation of digital content. Referring to the work carried out by the SHERPA Project in the UK with regard to the skills set for repository staff, the authors performed a survey among repository managers in Italy to assess the educational and professional background of the repository managers and the skills set required to implement successful institutional repositories. The survey findings show that the professional profile of the repository manager is a multiform and complex one. It requires cross-functional and highly specialised competencies. Italian repository managers are of the opinion that the skills required to promote the repository within the institution and those required to deal with copyright issues as the most essential skills repository managers should acquire and be trained for. Collection development and metadata expertise, familiarity with project management and expertise in repository workflow design are also highly rated. Technical skills are needed to deal with interoperability standards and protocols. In Italy academic curricula do not meet the repository managers’ educational needs. Academic programmes should be developed to include communication

  2. Implementing the EuroFIR Document and Data Repositories as accessible resources of food composition information.

    Science.gov (United States)

    Unwin, Ian; Jansen-van der Vliet, Martine; Westenbrink, Susanne; Presser, Karl; Infanger, Esther; Porubska, Janka; Roe, Mark; Finglas, Paul

    2016-02-15

    The EuroFIR Document and Data Repositories are being developed as accessible collections of source documents, including grey literature, and the food composition data reported in them. These Repositories will contain source information available to food composition database compilers when selecting their nutritional data. The Document Repository was implemented as searchable bibliographic records in the Europe PubMed Central database, which links to the documents online. The Data Repository will contain original data from source documents in the Document Repository. Testing confirmed the FoodCASE food database management system as a suitable tool for the input, documentation and quality assessment of Data Repository information. Data management requirements for the input and documentation of reported analytical results were established, including record identification and method documentation specifications. Document access and data preparation using the Repositories will provide information resources for compilers, eliminating duplicated work and supporting unambiguous referencing of data contributing to their compiled data. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Hydrothermal conditions around a radioactive waste repository

    International Nuclear Information System (INIS)

    Thunvik, R.; Braester, C.

    1981-12-01

    Numerical solutions for the hydrothermal conditions around a hard rock repository for nuclear fuel waste are presented. The objective of the present investigation is to illustrate in principle the effect of heat released from a hypothetical radioactive waste repository with regard to anisotropy in the rock permeability. Permeability and porosity are assumed to be constant or to decrease exponentially with depth. The hypothetical repository is situated below a horizontal ground surface or below the crest of a hill, and it is assumed that the water table follows the topography. Major interest in the analysis is directed towards the influence of anisotropy in the permeability on the flow patterns and travel times for water particles, being traced from the repository to the ground surface. The presented results show that anisotropy in the permeability may have a significant influence on the flow conditions around the repository and subsequently also on the travel times from the repository. (Authors)

  4. Waste package performance assessment

    International Nuclear Information System (INIS)

    Lester, D.H.

    1981-01-01

    This paper describes work undertaken to assess the life-expectancy and post-failure nuclide release behavior of high-level and waste packages in a geologic repository. The work involved integrating models of individual phenomena (such as heat transfer, corrosion, package deformation, and nuclide transport) and using existing data to make estimates of post-emplacement behavior of waste packages. A package performance assessment code was developed to predict time to package failure in a flooded repository and subsequent transport of nuclides out of the leaking package. The model has been used to evaluate preliminary package designs. The results indicate, that within the limitation of model assumptions and data base, packages lasting a few hundreds of years could be developed. Very long lived packages may be possible but more comprehensive data are needed to confirm this

  5. People's perception of LILW repository

    International Nuclear Information System (INIS)

    Zeleznik, Nadja; Polic, Marko

    2002-01-01

    Full text: Social acceptability of the radioactive waste repository presents a great problem in every country with such a waste. Even if people agree with the need for its construction, the chosen location should be far from their homes (NIMBY). The reasons for such attitudes were attributed to different causes: uneducated public, differences in understanding of radioactivity and risk by experts and lay public, risk communication problems, lack of credibility and social trust, etc. While in earlier days public was blamed for its irrationality, and need for education and information was emphasized, today it is realized that public trust is extremely important if effective risk communication is to be achieved. It is also recognized that it is not so much the content of the risk message itself, as the lack of trust to those responsible for provision of information that is behind this opposition. Perhaps we could apply here Petty and Caciopo's elaboration likelihood model of persuasion, with credibility as a factor in peripheral route of persuasion. Nevertheless also general lowering of social trust should explain social non-agreement. This lack of trust in experts and political institutions is perhaps caused by outwitting public in earlier years, its bad experiences with responsible officials, dangerous accidents (e.g. TMI, Chernobyl), increased influence that professions have over people's welfare, a greater value placed on equality and better educated public, etc. In 1996 the ARAO re-initiated the search for a LILW repository location with a new, so-called combined approach to the site selection, where the technical, geologically led process is combined with participation of local community. In order to get information on people's perception of the LILW repository construction, their willingness to accept it and factors that influence the acceptability, several surveys have been conducted. Groups of experts and lay persons answered the questionnaires. The results of

  6. Asse salt mine nuclear waste repository simulation experiments

    International Nuclear Information System (INIS)

    Coyle, A.J.

    1983-01-01

    The field tests underway in Asse, Federal Republic of Germany are dicected toward the development of test plans, techniques and equipment to be used in Exploratory Shafts or At Depth Test Facilities confirmation tests. These simulated repository tests will also provide information which address the following issues: brine migration (liquid and vapor); radiation effects of gamma rays; gas generation caused by radiation and corrosion; accelerated corrosion and leaching; altered properties of salt (the effects of heat, radiation and brine); and the effects of heat and radiation on test assemblies, instruments, and various materials exposed to repository conditions. This paper is a status of the first 82 days of operation of the Asse Brine Migration Tests, which were initiated on May 25, 1983. 6 references

  7. Confirmation of the applicability of low alkaline cement-based material in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Niunoya, Sumio; Minamide, Masashi

    2016-01-01

    In Japan, high-level radioactive waste repository will be constructed in a stable host rock formation more than 300 m underground. Tunnel support is used for safety during the construction and operation, so, shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement, water and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed the low alkaline cement, named as HFSC (Highly fly-ash contained silicafume cement), containing over 60wt% of silicafume (SF) and Fly-ash (FA). JAEA is presently constructing the underground research laboratory (URL) at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 350 m deep gallery in the Horonobe URL in 2013. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel constructed using HFSC shotcrete is about 112 m at 350 m deep drift. The workability of HFSC shotcrete was confirmed by this experimental construction. In this report, we present detailed results of the in-situ construction test. (author)

  8. Underground repository for radioactive wastes

    International Nuclear Information System (INIS)

    Cassibba, R.O.

    1989-01-01

    In the feasibility study for an underground repository in Argentina, the conceptual basis for the final disposal of high activity nuclear waste was set, as well as the biosphere isolation, according to the multiple barrier concept or to the engineering barrier system. As design limit, the container shall act as an engineering barrier, granting the isolation of the radionuclides for approximately 1000 years. The container for reprocessed and vitrified wastes shall have three metallic layers: a stainless steel inner layer, an external one of a metal to be selected and a thick intermediate lead layer preselected due to its good radiological protection and corrosion resistance. Therefore, the study of the lead corrosion behaviour in simulated media of an underground repository becomes necessary. Relevant parameters of the repository system such as temperature, pressure, water flux, variation in salt concentrations and oxidants supply shall be considered. At the same time, a study is necessary on the galvanic effect of lead coupled with different candidate metals for external layer of the container in the same experimental conditions. Also temporal evaluation about the engineering barrier system efficiency is presented in this thesis. It was considered the extrapolated results of corrosion rates and literature data about the other engineering barriers. Taking into account that corrosion is of a generalized type, the integrity of the lead shall be maintained for more than 1000 years and according to temporal evaluation, the multiple barrier concept shall retard the radionuclide dispersion to the biosphere for a period of time between 10 4 and 10 6 years. (Author) [es

  9. Groundwater movements around a repository

    International Nuclear Information System (INIS)

    Burgess, A.

    1977-10-01

    Based on regional models of groundwater flow, the regional hydraulic gradient at depth is equal to the regional topographic gradient. As a result, the equipotentials are near vertical. The permeability distribution with depth influences the groundwater flow patterns. A zone of sluggish flows, the quiescent zone is developed when the permeability decreases with depth. This feature is accentuated when horizontal anisotropy, with the horizontal permeability higher then the vertical permeability, is included. The presence of an inactive zone will be a prerequesite for a satisfactory repository site. The effect of an inclined discontinuity representing a singular geological feature such as a fault plane or shear zone has been modelled. The quiescent zone does not appear to be unduly disturbed by such a feature. However, meaningful quantitative predictions related to the flows in a typical singular feature cannot be made without more specific data on their hydraulic properties. Two dimensional analysis has been made for a site specific section of a candidate repository site at Forsmark, Sweden. The lateral extent of the model was defined by major tectonic features, assumed vertical. Potential gradients and pore velocities have been computed for a range of boundary conditions and assumed material properties. The potential gradients for the model with anisotropic permeability approach the average potential gradient between the boundaries. The result of this study of the initial groundwater conditions will be used as input data for the analyses of the thermomechanical perturbations of the groundwater regime. In the long term, the groundwater flow will return to the initial conditions. The residual effects of the repository on the flow will be discussed in part 2 of this report. (author)

  10. National radioactive wasterRepository Mochovce

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the scheme of the Mochovce National radioactive waste repository for the Slovak Republic is presented. The National radioactive waste repository in Mochovce is a surface type storage facility. It is intended for final disposal of solid and solidified low and intermediate radioactive waste produced during the operation of nuclear power plants and institutions located within the territory of the Slovak Republic. The Repository site is situated about 2 km northwest to the Mochovce NPP

  11. Regulatory status on the safety assessment of a HLW repository in other countries

    International Nuclear Information System (INIS)

    Lee, Sung Ho; Hwang, Yong Soo

    2008-12-01

    To construct a HLW repository, it is essential to meet the requirements on the regulation for a deep geological disposal. Even if the construction of a HLW repository is determined positively, technical standards which assert the performance of a repository will be needed. Among various technical standards, safety assessment based on the repository evolution in the future will play an important role in the licensing process. The foreign countries' technical standards on the safety assessment of a HLW repository may be an indicator to carry out the R and D activities on geological disposal effectively. In this report, assessment period, limit of radiation dose and uncertainty related to the safety assessment are investigated and analyzed in detail. Especially, the technical reviews of USA regulation bodies seems to be reasonable in the point of the intrinsic attribute of safety assessment

  12. Evaluation of radiological safety assessment of a repository in a clay rock formation

    International Nuclear Information System (INIS)

    1999-01-01

    This report presents a comprehensive description of the post-closure radiological safety assessment of a repository for the spent fuel arisings resulting from the Spanish nuclear program excavated in a clay host rock formation. In this report three scenarios have been analysed in detail. The first scenario represents the normal in detail. The first scenario represents the normal evolution of the repository (Reference Scenario); and includes a set of variants to investigate the relative importance of the various repository components and examine the sensitivity of the performance to parameters variations. Two altered scenarios have also been considered: deep well construction and poor sealing of the repository. This document contains a detailed description of the repository system, the methodology adopted for the scenarios generation, the process modelling approach and the results of the consequences analysis. (Author)

  13. System analysis methods for geological repository of high level radioactive waste in granite

    International Nuclear Information System (INIS)

    Chen Weiming; Wang Ju; Li Yunfeng; Jin Yuanxin; Zhao Honggang

    2009-01-01

    Taking Beishan granite site as an example, this paper proposes the conceptual and structural design of repository for high level radioactive waste at first. Then the function, structure, environment and evolution of the repository are described by the methodology of system analysis. Based on these designs and descriptions, a calculation model for the repository is developed with software GoldSim. At last, this calculation model is applied to emulate the space-time distribution of repository radiotoxicity, to analyze the sensitivity of parameters in the model, to optimize the design parameters, and to predict and assess the repository performance. The results of this study can provide technical supports for resources allocation and coordination of R and D projects. (authors)

  14. Environmental effects on corrosion in the Tuff repository

    International Nuclear Information System (INIS)

    Beavers, J.A.; Thompson, N.G.

    1990-02-01

    Cortest Columbus is investigating the long-term performance of container materials used for high-level waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy's application to construct a geologic repository for high-level radioactive waste. The scope of work consists of employing short-term techniques, to examine a wide range of possible failure modes. Long-term tests are being used to verify and further examine specific failure modes identified as important by the short-term studies. The original focus of the program was on the salt repository but the emphasis was shifted to the Tuff repository. This report summarizes the results of a literature survey performed under Task 1 of the program. The survey focuses on the influence of environmental variables on the corrosion behavior of candidate container materials for the Tuff repository. Environmental variables considered include: radiation, thermal and microbial effects. 80 refs., 44 figs., 44 tabs

  15. Office of Geologic Repositories quality assurance plan for high-level radioactive waste repositories

    International Nuclear Information System (INIS)

    1986-08-01

    This document sets forth geologic repository program-wide quality assurance program requirements and defines management's quality assurance responsibilities for the Office of Geologic Repositories and its projects. (LM)

  16. The European Repository Landscape 2008 Inventory of Digital Repositories for Research Output

    CERN Document Server

    Van der Graaf, Maurits

    2009-01-01

    It is widely acknowledged that a common knowledge base for European research is necessary. Research repositories are an important innovation to the scientific information infrastructure. In 2006, digital repositories in the 27 countries of the European we

  17. Thermal Management and Analysis for a Potential Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Dr. A. Van Luik

    2004-01-01

    In the current Yucca Mountain repository design concept, heat from the emplaced waste (mostly from spent nuclear fuel) would keep the temperature of the rock around the waste packages higher than the boiling point of water for hundreds to thousands of years after the repository is closed. The design concept allows below-boiling portions of the pillars between drifts to serve as pathways for the drainage of thermally mobilized water and percolating groundwater by limiting the distance that boiling temperatures extend into the surrounding rock. This design concept takes advantage of host rock dry out, which would create a dry environment within the emplacement drifts and reduce the amount of water that might otherwise be available to enter the drifts and contact the waste packages during this thermal pulse. Table 1 provides an overview of design constraints related to thermal management after repository closure. The Yucca Mountain repository design concept also provides flexibility to allow for operation over a range of lower thermal operating conditions. The thermal conditions within the emplacement drifts can be varied, along with the relative humidity, by modifying operational parameters such as the thermal output of the waste packages, the spacing of the waste packages in the emplacement drifts, and the duration and rate of active and passive ventilation. A lower range has been examined to quantify lower-temperature thermal conditions (temperatures and associated humidity conditions) in the emplacement drifts and to quantify impacts to the required emplacement area and excavated drift length. This information has been used to evaluate the potential long-term performance of a lower-temperature repository and to estimate the increase in costs associated with operating a lower-temperature repository. This presentation provides an overview of the thermal management evaluations that have been conducted to investigate a range of repository thermal conditions and

  18. Workshop: Creating Your Institutional Research Repository

    KAUST Repository

    Grenz, Daryl M.

    2016-11-08

    In 2002, the Scholarly Publishing and Academic Resources Coalition (SPARC) proposed the concept of an institutional repository to simultaneously disrupt and enhance the state of scholarly communications in the academic world. Thirteen years later, thousands of universities and other institutions have answered this call, but many more have not due to gaps in budgets, awareness and, most of all, practical guidance on creating an institutional repository. This workshop provides you with an essential primer on what it takes to establish a fully-functioning institutional repository. Every aspect of the process will be covered, including policies, procedures, staffing guidelines, workflows and repository technologies.

  19. Center for Leadership Development (CLD) Repository

    Data.gov (United States)

    Office of Personnel Management — The Center for Leadership Development Repository stores various data including policies, procedures, governance, guidance, security, and financial documents of the...

  20. 1972 preliminary safety analysis report based on a conceptual design of a proposed repository in Kansas

    International Nuclear Information System (INIS)

    Blomeke, J.O.

    1977-08-01

    This preliminary safety analysis report is based on a proposed Federal Repository at Lyons, Kansas, for receiving, handling, and depositing radioactive solid wastes in bedded salt during the remainder of this century. The safety analysis applies to a hypothetical site in central Kansas identical to the Lyons site, except that it is free of nearby salt solution-mining operations and bore holes that cannot be plugged to Repository specifications. This PSAR contains much information that also appears in the conceptual design report. Much of the geological-hydrological information was gathered in the Lyons area. This report is organized in 16 sections: considerations leading to the proposed Repository, design requirements and criteria, a description of the Lyons site and its environs, land improvements, support facilities, utilities, different impacts of Repository operations, safety analysis, design confirmation program, operational management, requirements for eventually decommissioning the facility, design criteria for protection from severe natural events, and the proposed program of experimental investigations