Design principle of TVO's final repository and preliminary adaptation to site specific conditions

International Nuclear Information System (INIS)

Salo, J-P.; Reikkola, R.

1995-01-01

Teollisuuden Voima Oy (TVO) is responsible for the management of spent fuel produced by the Olkiluoto power plant. TVO's current programme of spent fuel management is based on the guidelines and time schedule set by the Finnish Government. TVO has studied a final disposal concept in which the spent fuel bundles are encapsulated in copper canisters and emplaced in Finnish bedrock. According to the plan the final repository for spent fuel will be in operation by 2020. TVO's updated technical plans for the disposal of spent fuel together with a performance analysis (TVO-92) were submitted to the authorities in 1992. The paper describes the design principle of TVO's final repository and preliminary adaptation of the repository to site specific conditions. (author). 10 refs., 5 figs

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.

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.

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

HYDRIDE-RELATED DEGRADATION OF SNF CLADDING UNDER REPOSITORY CONDITIONS

International Nuclear Information System (INIS)

McCoy, K.

2000-01-01

The purpose and scope of this analysis/model report is to analyze the degradation of commercial spent nuclear fuel (CSNF) cladding under repository conditions by the hydride-related metallurgical processes, such as delayed hydride cracking (DHC), hydride reorientation and hydrogen embrittlement, thereby providing a better understanding of the degradation process and clarifying which aspects of the process are known and which need further evaluation and investigation. The intended use is as an input to a more general analysis of cladding degradation

Study of environmental conditions in the repositories of the National Archive of the Republic of Cuba

Directory of Open Access Journals (Sweden)

Isbel Vivar González

2016-01-01

Full Text Available The aim was to study the behavior of the temperature (T, relative humidity (RH and illuminance (I in the repositories of the National Archive of the Republic of Cuba. The values of T and RH were measured twice daily for four consecutive years. I was measured in sunny and cloudy days. The result sallow us to affirm that the environmental conditions (T, RH of these repositories are favorable for the conservation of paper documents. In cloudy days, I of the repositories located in lower-ground floor does not exceed the allowed 50 lux; but in sunny days, due to the incidence of sunlight, in all repositories I exceeds 50 lux. Artificial light caused an increase in I in all repositories, but this is not significant because the light bulbs are kept turned off most of the time.

Improvement of storage conditions and closure of the radioactive waste repository - Rozan

International Nuclear Information System (INIS)

Dutton, L.M.C.; Pacey, N.R.; Buckley, M.J.; Thomson, J.G.; Miller, W.; Barraclough, I.; Tomczak, W.; Mitrega, J.; Smietanski, L.

2005-01-01

The Rozan repository is a near-surface repository on the site of an ex-military fort, operated by Radioactive Waste Management Plant (RWMP). Solid or encapsulated waste is consigned to the repository. Low- and medium-activity waste produced in Poland is collected, processed, solidified and prepared for disposal at the Swierk facility. The waste is currently stored or disposed of within the fort structures, these have robust concrete walls, that provide both shielding and containment. The project, funded by the European Commission through the Phare Programme, aimed to improve the storage conditions and determine a strategy for closure achieving two key results; Stakeholder agreement to a strategy for the management and closure of the repository, and; Approval by the National Atomic Energy Agency of the safety case for the selected strategy. The strategy was selected using a multi-criteria analysis methodology at workshops that involved experts, regulators and other stakeholders. The selected strategy proposed that the waste in Facilities 3A and 8 should be left in situ and these facilities should continue to operate until the repository is closed. The waste in Rooms K7 to K9 of Facility 1 and in Facilities 2 and 3 should be retrieved, assayed, treated and packaged prior to redisposal. The short-lived waste that is retrieved from Rooms K7 to K9 of Facility 1 and Facilities 2 and 3 should be emplaced in Facility 8 subject to acceptance by the NAEA of the dose of 0.3mSv/y that might occur at long times in the future from a very unlikely scenario. When operations at the repository end, Facilities 3A and 8 should be covered with a multi-layer cap. Following selection of the strategy, assessment work was undertaken to support the production of the suite of safety cases. (author)

Methodology for determining time-dependent mechanical properties of tuff subjected to near-field repository conditions

International Nuclear Information System (INIS)

Blacic, J.D.; Andersen, R.

1983-01-01

We have established a methodology to determine the time dependence of strength and transport properties of tuff under conditions appropriate to a nuclear waste repository. Exploratory tests to determine the approximate magnitudes of thermomechanical property changes are nearly complete. In this report we describe the capabilities of an apparatus designed to precisely measure the time-dependent deformation and permeability of tuff at simulated repository conditions. Preliminary tests with this new apparatus indicate that microclastic creep failure of tuff occurs over a narrow strain range with little precursory Tertiary creep behavior. In one test, deformation under conditions of slowly decreasing effective pressure resulted in failure, whereas some strain indicators showed a decreasing rate of strain

Methodology for determining time-dependent mechanical properties of tuff subjected to near-field repository conditions

Energy Technology Data Exchange (ETDEWEB)

Blacic, J.D.; Andersen, R.

1983-01-01

We have established a methodology to determine the time dependence of strength and transport properties of tuff under conditions appropriate to a nuclear waste repository. Exploratory tests to determine the approximate magnitudes of thermomechanical property changes are nearly complete. In this report we describe the capabilities of an apparatus designed to precisely measure the time-dependent deformation and permeability of tuff at simulated repository conditions. Preliminary tests with this new apparatus indicate that microclastic creep failure of tuff occurs over a narrow strain range with little precursory Tertiary creep behavior. In one test, deformation under conditions of slowly decreasing effective pressure resulted in failure, whereas some strain indicators showed a decreasing rate of strain.

Permeability and long-term durability of concrete in final repository conditions

International Nuclear Information System (INIS)

Pihlajavaara, S.

1990-02-01

The interrelation of the permeability properties and longterm durability especially in wet repository conditions has been studied. The study is based on the author's long-term experience, literary survey and experiments on the durability, service life prediction, and on water and gas permeability. Degradation models and experimental results on water and gas permeability are presented. The experiments made indicated that high class concrete is practically water and gas tight, especially in the long run when stored under water. This meant that there will hardly be any mass transfer into concrete or out of it, if concrete is of good quality. Concrete structures can be designed to meet the required service life. It can be said that practically the precision increases and the scatter decreases in the service life estimation significantly when the thickness of the anticipated deteriorated surface layer is smaller due to the higher concrete quality. The service life of well-designed concrete silo walls made of high class concrete can be predicted to be at least 1000 years in the repository conditions. (orig.)

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

Information about activity, status and radiation conditions of Republic radioactive waste repository

International Nuclear Information System (INIS)

Saidumarov, P.

2000-01-01

All radioactive wastes in the Republic of Uzbekistan are stored in the Republic Radioactive Waste Repository in Parkent district of Tashkent region. In the facility there are 2 tanks for solid radioactive waste, each of 800 m 3 , one of them is full, second is in operation; 2 tanks for liquid radioactive waste each tank of 200 m 3 , both of them are empty; 6 storages, each of 3 m 3 all of them are empty; 3 storages for spent radioactive sources, one of them is full, 2 of them are in operation; 4 storages for high level radioactive waste, each storage of 3.5 m 3 , one of them is in operation, 3 are empty; one sealed storage containing 135 m 3 of concrete blocks with waste from electronic industry. According to conclusions of a few competent examinations RRWR does not cause damage to the environment. Geographic location and technical conditions of the repository are satisfactory. Low deposition of underground water (62 m) excludes penetration of radioisotopes. There were no radiation accidents during the repository operation

Radionuclide release from high level waste forms under repository conditions in clay or granite

International Nuclear Information System (INIS)

Godon, N.; Lanza, F.

1990-01-01

The behaviour of both fully active and simulated vitrified high level waste (HLW) has been studied under conditions that are likely to occur in future repositories in clay and granite. The simulated HLW was doped with Cs, Sr, Tc and the actinides and the leaching of these elements from the glass has been measured together with their concentrations in the water of the near-field and their distribution between the various components of the repository. The diffusion coefficients of several elements in Boom clay has also been measured. The results show that the concentrations of Tc and the actinides in the near-field of a repository will be very low and that the actinides will only diffuse very slowly away from the vicinity of the glass. 24 refs., 1 figs., 7 tabs

Wetting of bituminized ion-exchangers under simulated repository conditions

International Nuclear Information System (INIS)

Aalto, H.; Valkiainen, M.

2001-01-01

According to the present plans the spent nuclear fuel from four Finnish nuclear power units will be transferred after interim storage to the final disposal site where it will be encapsulated and disposed of in a final repository constructed into the bedrock at a depth of 500 meters. Low and medium level waste generated at nuclear power plants will be finally disposed of in caverns constructed in the bedrock at the power plant site. The safety of the final disposal is based on a multibarrier concept and the degree of safety is estimated by using predictive models. The properties of the waste form are taken into account in the design of the repository construction. Bitumen has been chosen as an immobilisation agent for the wet wastes at Olkiluoto Power Plant, where two BWR units, TVO 1 and TVO 2, have separate bituminization facilities designed by Asea-Atom. Properties of bituminized spent ion-exchange resins from Olkiluoto power plant have been studied by VTT Chemical Technology since the late 70's. These studies have concentrated mainly on determining the long-term behaviour of the bituminization product under the repository conditions. Current interest lies on wetted product as a diffusion barrier. For this purpose a microscopic method for the visualisation of the structure of the wetted product has been developed. The equilibration of the samples in simulated concrete groundwater is currently going on at a temperature of 5-8 deg. C. Preliminary results are presented in this paper. Diffusion experiments have been planned for the further characterising of the wetted product as a release barrier for radionuclides including modelling. (author)

Testing of high-level waste forms under repository conditions

International Nuclear Information System (INIS)

Mc Menamin, T.

1989-01-01

The workshop on testing of high-level waste forms under repository conditions was held on 17 to 21 October 1988 in Cadarache, France, and sponsored by the Commission of the European Communities (CEC), the Commissariat a l'energie atomique (CEA) and the Savannah River Laboratory (US DOE). Participants included representatives from Australia, Belgium, Denmark, France, Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, The United Kingdom and the United States. The first part of the conference featured a workshop on in situ testing of simulated nuclear waste forms and proposed package components, with an emphasis on the materials interface interactions tests (MIIT). MIIT is a sevent-part programme that involves field testing of 15 glass and waste form systems supplied by seven countries, along with potential canister and overpack materials as well as geologic samples, in the salt geology at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, USA. This effort is still in progress and these proceedings document studies and findings obtained thus far. The second part of the meeting emphasized multinational experimental studies and results derived from repository systems simulation tests (RSST), which were performed in granite, clay and salt environments

Preclosure radiological safety analysis for accident conditions of the potential Yucca Mountain Repository: Underground facilities

International Nuclear Information System (INIS)

Ma, C.W.; Sit, R.C.; Zavoshy, S.J.; Jardine, L.J.; Laub, T.W.

1992-06-01

This preliminary preclosure radiological safety analysis assesses the scenarios, probabilities, and potential radiological consequences associated with postulated accidents in the underground facility of the potential Yucca Mountain repository. The analysis follows a probabilistic-risk-assessment approach. Twenty-one event trees resulting in 129 accident scenarios are developed. Most of the scenarios have estimated annual probabilities ranging from 10 -11 /yr to 10 -5 /yr. The study identifies 33 scenarios that could result in offsite doses over 50 mrem and that have annual probabilities greater than 10 -9 /yr. The largest offsite dose is calculated to be 220 mrem, which is less than the 500 mrem value used to define items important to safety in 10 CFR 60. The study does not address an estimate of uncertainties, therefore conclusions or decisions made as a result of this report should be made with caution

Nye County Nuclear Waste Repository Project Office independent scientific investigations program annual report, May 1997 - April 1998

International Nuclear Information System (INIS)

1998-07-01

This annual summary report, prepared by the Nye County Nuclear Waste Repository Project Office (NWRPO), summarizes the activities that were performed during the period from May 1, 1997 to April 30, 1998. These activities were conducted in support of the Independent Scientific Investigation Program (ISIP) of Nye County at the Yucca Mountain Site (YMS). The Nye County NWRPO is responsible for protecting the health and safety of the Nye County residents. NWRPO's on-site representative is responsible for designing and implementing the Independent Scientific Investigation Program (ISIP). Major objectives of the ISIP include: Investigating key issues related to conceptual design and performance of the repository that can have major impact on human health, safety, and the environment; identifying areas not being addressed adequately by the Department of Energy (DOE). Nye County has identified several key scientific issues of concern that may affect repository design and performance which were not being adequately addressed by DOE. Nye County has been conducting its own independent study to evaluate the significance of these issues. This report summarizes the results of monitoring from two boreholes and the Exploratory Studies Facility (ESF) tunnel that have been instrumented by Nye County since March and April of 1995. The preliminary data and interpretations presented in this report do not constitute and should not be considered as the official position of Nye County. The ISIP presently includes borehole and tunnel instrumentation, monitoring, data analysis, and numerical modeling activities to address the concerns of Nye County

Nye County Nuclear Waste Repository Project Office independent scientific investigations program annual report, May 1997--April 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

This annual summary report, prepared by the Nye County Nuclear Waste Repository Project Office (NWRPO), summarizes the activities that were performed during the period from May 1, 1997 to April 30, 1998. These activities were conducted in support of the Independent Scientific Investigation Program (ISIP) of Nye County at the Yucca Mountain Site (YMS). The Nye County NWRPO is responsible for protecting the health and safety of the Nye County residents. NWRPO`s on-site representative is responsible for designing and implementing the Independent Scientific Investigation Program (ISIP). Major objectives of the ISIP include: Investigating key issues related to conceptual design and performance of the repository that can have major impact on human health, safety, and the environment; identifying areas not being addressed adequately by the Department of Energy (DOE). Nye County has identified several key scientific issues of concern that may affect repository design and performance which were not being adequately addressed by DOE. Nye County has been conducting its own independent study to evaluate the significance of these issues. This report summarizes the results of monitoring from two boreholes and the Exploratory Studies Facility (ESF) tunnel that have been instrumented by Nye County since March and April of 1995. The preliminary data and interpretations presented in this report do not constitute and should not be considered as the official position of Nye County. The ISIP presently includes borehole and tunnel instrumentation, monitoring, data analysis, and numerical modeling activities to address the concerns of Nye County.

Nuclear waste repository simulation experiments, Asse salt mine, Federal Republic of Germany. Annual report 1984

International Nuclear Information System (INIS)

Rothfuchs, T.; Feddersen, H.K.; Schwarzianeck, P.; Staupendahl, G.; Coyle, A.J.; Eckert, J.; Kalia, H.

1986-07-01

This is the second joint annual report (1984) on experiments simulating a nuclear waste repository at the 800-m (2624-ft) level of the Asse salt mine in the Federal Republic of Germany. This report describes the Asse salt mine, the test equipment, and the pretest properties of the salt in the mine and in the vicinity of the test area. Also included are test data for the first 19 months of operation on the following: brine migration rates, thermal mechanical behavior of the salt (including room closure, stress reading, and thermal profiles), and borehole gas pressures. In addition to field data, laboratory analyses of results are included in this report. The duration of the experiment will be 2 years, ending in December 1985

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

Nye County nuclear waste repository project office independent scientific investigations program. Summary annual report, May 1996--April 1997

International Nuclear Information System (INIS)

1997-05-01

This annual summary report, prepared by Multimedia Environmental Technology, Inc. (MET) on behalf of Nye County Nuclear Waste Project Office, summarizes the activities that were performed during the period from May 1, 1996 to April 30, 1997. These activities were conducted in support of the Independent Scientific Investigation Program (ISIP) of Nye County at the Yucca Mountain Site (YMS). The Nye County NWRPO is responsible for protecting the health and safety of the Nye County residents. NWRPO's on-site representative is responsible for designing and implementing the Independent Scientific Investigation Program (ISIP). Major objectives of the ISIP include: (1) Investigating key issues related to conceptual design and performance of the repository that can have major impact on human health, safety, and the environment. (2) Identifying areas not being addressed adequately by DOE Nye County has identified several key scientific issues of concern that may affect repository design and performance which were not being adequately addressed by DOE. Nye County has been conducting its own independent study to evaluate the significance of these issues

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

Long-term degradation of organic polymers under conditions found in deep repositories for low and intermediate-level wastes

International Nuclear Information System (INIS)

Warthmann, R.; Mosberger, L.; Baier, U.

2013-06-01

On behalf of Nagra, the Environmental Biotechnology Section of the Zürich University of Applied Sciences in Wädenswil investigated the potential for microbiological degradation of organic polymers under the conditions found in a deep geological repository for low- and intermediate-level waste (L/ILW). The existing scientific literature on the topic was analysed, some thermodynamic calculations carried out and input was elicited from internationally recognised experts in the field. The study was restricted to a few substances which, in terms of mass, are most significant in the Swiss L/ILW inventory; these are polystyrene (PS), polyvinyl chloride (PVC), other plastics and bitumen. There were no clear indications in the literature that the polymer structure of synthetic polymers is biodegraded under anoxic conditions. However, functional groups of ion exchangers and plasticizers in plastics are considered to be readily available and biodegradable. The greatest obstacle to biological degradation of synthetic polymers is depolymerisation to produce labile monomers. As energy is generally required for such breakdown, the chances of this process taking place outside the cells are very low. In so far as they are present, monomers are, in principle, anaerobically biodegradable. Thermodynamic considerations indicate that degradation of synthetic polymers under repository conditions is theoretically possible. However, the degradation of polystyrene is very close to thermodynamic equilibrium and the usable energy for microorganisms would barely be sufficient. Under high H2 partial pressures, it is predicted that there will be a thermodynamic inhibition of anaerobic degradation, as certain interim steps in degradation are endergonic. The starting conditions for microbial growth in a deep repository are unfavourable in terms of availability of water and prevailing pH values. Practically no known microorganisms can tolerate the combination of these conditions; most known

Coupling fuel cycles with repositories: how repository institutional choices may impact fuel cycle design

International Nuclear Information System (INIS)

Forsberg, C.; Miller, W.F.

2013-01-01

The historical repository siting strategy in the United States has been a top-down approach driven by federal government decision making but it has been a failure. This policy has led to dispatching fuel cycle facilities in different states. The U.S. government is now considering an alternative repository siting strategy based on voluntary agreements with state governments. If that occurs, state governments become key decision makers. They have different priorities. Those priorities may change the characteristics of the repository and the fuel cycle. State government priorities, when considering hosting a repository, are safety, financial incentives and jobs. It follows that states will demand that a repository be the center of the back end of the fuel cycle as a condition of hosting it. For example, states will push for collocation of transportation services, safeguards training, and navy/private SNF (Spent Nuclear Fuel) inspection at the repository site. Such activities would more than double local employment relative to what was planned for the Yucca Mountain-type repository. States may demand (1) the right to take future title of the SNF so if recycle became economic the reprocessing plant would be built at the repository site and (2) the right of a certain fraction of the repository capacity for foreign SNF. That would open the future option of leasing of fuel to foreign utilities with disposal of the SNF in the repository but with the state-government condition that the front-end fuel-cycle enrichment and fuel fabrication facilities be located in that state

Digital Repositories An investigation of best practices for content recruitment to academic digital repositories and the conditions for their livelihood

CERN Document Server

Hagen, Reidun Anette

2009-01-01

A digital repository is a web accessible database, aimed at preserving the research material of an institution or scientific community. A digital repository serves as a tool for dissemination of research material and can increase the impact of the research by making it freely accessible. Digital repositories are often mentioned as a possible aid in relation to the Open Access debate; how research material should be freely accessible to anyone, anywhere at any time. However, for a digital repository to fully unleash its potential as a crucial component of Open Access, it is reliant on the ability to successfully collect and organize content. To a large extent this involves initiating self-archiving of research material by scientists throughout the academic world. This is not a trivial task, and many current repositories are inadequate in this respect, remaining empty, unvisited shelves. This thesis explores best practices for content recruitment to digital repositories, through the review of literature, and an...

Spent fuel stability under repository conditions - final report of the european project

International Nuclear Information System (INIS)

Poinssot, Ch.; Ferry, C.; Kelm, M.; Cavedon, J.M.; Corbel, C.; Jegou, Ch.; Lovera, P.; Miserque, F.; Poulesquen, A.; Grambow, B.; Andriambololona, Z.; Martinez-Esparza, A.; Kelm, M.; Loida, A.; Rondinella, V.; Wegen, D.; Spahiu, K.; Johnson, L.; Cachoir, Ch.; Lemmens, K.; Quinones, J.; Bruno, J.; Christensen, H.; Grambow, B.; Pablo, J. de

2005-01-01

This report is the final report of the European Project 'Spent Fuel Stability under Repository Conditions' (FIKW-CT-2001-00192 SFS) funded by the European Commission from Nov.2000 to Oct.2004. Gathering the work performed by 13 partners from 6 countries, it aims to specifically focus on the spent nuclear fuel long term alteration in deep repository and the subsequent radionuclides release rate as a function of time. This report synthesised the wide experimental work performed within this project and enlightens the major outcomes, which can be summarised as follow: - A new model for defining the Instant Release Fraction was developed in order to consider the potential fuel evolution before the water penetrates the canister. Quantitative assessment has been produced and shows a significant contribution to the long term dose; - Based on new experimental data, kinetic radiolytic scheme have been upgraded and are used to determine the amount of oxidants produced at the fuel/water interface; - The existence of a dose threshold below which the water radiolysis does not influence the fuel alteration has been demonstrated and occurs between 3.5 and 33 MBq.g UO21. Above the threshold, the fuel alteration rates is directly related to the dose rate. - Hydrogen was experimentally demonstrated to be an efficient oxidants scavenger preventing therefore the fuel oxidation. Molecular mechanism still need to be understood. - Finally, a new Matrix Alteration Model integrating most of the SFS results (apart of the hydrogen effect) has been developed and used to assess the fuel long tern stability in representative conditions of deep repository in salt, clay-rock and granite. The breadth of the results and the significance of the conclusions testify of the success of the collaboration within the project. (authors)

Design information verification for spent fuel conditioning plants and for geological repositories

International Nuclear Information System (INIS)

Myatt, J.; Ward, M.D.

1995-01-01

The disposal of spent fuel is a major option for the back-end of the nuclear fuel cycle. It will require the construction, operation and eventual closure of conditioning plants and geological repositories. Consequently, a safeguards approach including Design Information Verification (DIV) must be developed for these facilities. DIV Is the examination of a completed facility to verify that it has been built to the design declared by the operator. Although DIV takes place chiefly before a plant begins routine operation, there is a continuing interest in ensuring that the plant remains as declared. That is, that the continuity of knowledge of design information is maintained during the operational phase of the plant and also post closure if necessary. A major problem with DIV of a repository is that there will be continuous structural changes during its operational life requiring advanced or special techniques for reverification. Some of these are briefly reviewed. Furthermore, since a disposal facility is expected to be operational for several decades, new mining technology may also have an impact on the DIV methods employed. Another factor in the safeguards supervision of a repository is that when the fuel has been backfilled and/or scaled in place a reassay will be a very costly exercise. The role of DIV in such novel circumstances must, therefore, be fully considered

Initial results from dissolution rate testing of N-Reactor spent fuel over a range of potential geologic repository aqueous conditions

International Nuclear Information System (INIS)

Gray, W.J.; Einziger, R.E.

1998-04-01

Hanford N-Reactor spent nuclear fuel (HSNF) may ultimately be placed in a geologic repository for permanent disposal. To determine whether the engineered barrier system that will be designed for emplacement of light-water-reactor (LWR) spent fuel will also suffice for HSNF, aqueous dissolution rate measurements were conducted on the HSNF. The purpose of these tests was to determine whether HSNF dissolves faster or slower than LWR spent fuel under some limited repository-relevant water chemistry conditions. The tests were conducted using a flowthrough method that allows the dissolution rate of the uranium matrix to be measured without interference by secondary precipitation reactions that would confuse interpretation of the results. Similar tests had been conducted earlier with LWR spent fuel, thereby allowing direct comparisons. Two distinct corrosion modes were observed during the course of these 12 tests. The first, Stage 1, involved no visible corrosion of the test specimen and produced no undissolved corrosion products. The second, Stage 2, resulted in both visible corrosion of the test specimen and left behind undissolved corrosion products. During Stage 1, the rate of dissolution could be readily determined because the dissolved uranium and associated fission products remained in solution where they could be quantitatively analyzed. The measured rates were much faster than has been observed for LWR spent fuel under all conditions tested to date when normalized to the exposed test specimen surface areas. Application of these results to repository conditions, however, requires some comparison of the physical conditions of the different fuels. The surface area of LWR fuel that could potentially be exposed to repository groundwater is estimated to be approximately 100 times greater than HSNF. Therefore, when compared on the basis of mass, which is more relevant to repository conditions, the HSNF and LWR spent fuel dissolve at similar rates

Groundwater movements around a repository. Geological and geotechnical conditions

International Nuclear Information System (INIS)

Stille, H.; Burgess, A.; Lindblom, U.E.

1977-09-01

The report was prepared as one of a series of technical reports within a study of the groundwater movements around a repository for radioactive waste in the Precambrian bedrock of Sweden. This assessment is intended to provide basic geotechnical data for the analysis. These data include properties and conditions that are representative of the intact rock, the rock mass in general, and the groundwater regime. As there exist a considerable range in the mineralogy of potentially suitable plutonic rocks and since a specific site has not yet been selected, all of the parameters presented in this report must be based on presumptive geological and hydrogeological conditions. Where possible, data for two potential site areas, namely Oskarshamn and Forsmark, are presented. This report is divided into four parts. First, a brief description of the procedure for modelling groundwater movements is presented, along with a tabulation of the important parameters. Secondly, a description of the geological and hydrogeological conditions of the Fennoscandian shield, as well as of the two general site areas, is given. The final two sections of the report provide thermomechanical and geohydrological characteristics and properties of the host rock

Low temperature spent fuel oxidation under tuff repository conditions

International Nuclear Information System (INIS)

Einziger, R.E.; Woodley, R.E.

1985-01-01

The Nevada Nuclear Waste Storage Investigations Project is studying the suitability of tuffaceous rocks at Yucca Mountain, Nye County, Nevada, for high level waste disposal. The oxidation state of LWR spent fuel in a tuff repository may be a significant factor in determining its ability to inhibit radionuclide migration. Long term exposure at low temperatures to the moist air expected in a tuff repository is expected to increase the oxidation state of the fuel. A program is underway to determine the spent fuel oxidation mechanisms which might be active in a tuff repository. Initial work involves a series of TGA experiments to determine the effectiveness of the technique and to obtain preliminary oxidation data. Tests were run at 200 0 C and 225 0 C for as long as 720 hours. Grain boundary diffusion appears to open up a greater surface area for oxidation prior to onset of bulk diffusion. Temperature strongly influences the oxidation rates. The effect of moisture is small but readily measurable. 25 refs., 7 figs., 4 tabs

Sorption of Np by UO2 under repository conditions

Science.gov (United States)

Kazakovskaya, T. V.; Zakharova, E. V.; Haire, M. J.

2010-03-01

This work is a part of the joint Russian - American Program on Beneficial Use of Depleted Uranium. The production of nuclear fuels results in the accumulation of large quantities of depleted uranium (DU) in the form of uranium hexafluoride (UF6), which is converted to uranium oxides. Depleted uranium dioxide (DUO2) can be used as a component of radiation shielding and as an absorbent for migrating radionuclides that may emerge from casks containing spent nuclear fuel (SNF) that are stored for hundreds of thousands of years in high-level wastes (HLW) and SNF repositories (e.g. Yucca Mountain Project). In this case DU oxides serve as an additional engineered chemical barrier. It is known that the primary radioisotope contributor to the calculated long-term radiation dose to the public at the Yucca Mountain SNF repository site boundary is neptunium-237 (237Np). This paper describes the sorption of 237Np in various media (deionized water and J-13 solution) by DUO2. Samples of DUO2 used in this work originated from the treatment of UF6 in a reducing media to form UO2(DUO2-1 at 600°C, DUO2-2 at 700°C, and DUO2-3 at 800°C). All species of DUO2 sorb Np(V) and Np(IV) from aqueous media. Equilibrium was achieved in 24 hours for Np(V) and in 2 hours for Np(IV). Np(V) sorption is accompanied with partial reduction of Np(V) to Np(IV) and vice versa. The sorption of Np(V) onto DUO2 surfaces is irreversible. The investigations on DUO2 transformations were performed under dynamic and static conditions. Under static conditions the solubility of the DUO2 samples in J-13 solution is considerably higher than in DW. When the pre-treatment temperature is decreased, the solubility of DUO2 samples raises regardless of the media. The experiments on interaction between DUO2 and aqueous media (DW and J-13 solution) under dynamic conditions demonstrated that during 30-40 days the penetration/filtration rate of DW and J-13 solution through a thin DUO2 layer decreased dramatically, and then

Geotechnical conditions of Bulgaria and site selection for radioactive waste repository

International Nuclear Information System (INIS)

Iliev, I.; Tacheva, E.

1993-01-01

A comparative study of the complex structure of the Bulgarian lands and the engineering geological criteria for site selection of national repositories for high level radwastes is made. A detailed description of the following geotechnical conditions of Bulgaria's territory is given: genetic, lithological and engineering-geological types of rocks; physico-mechanical parameters of the most widespread rocky and semi-rocky engineering geological types; fissuring of the rocks; rock massifs; geodynamic processes. The number of promising variants for repositories have been classified according to the structure of the rock massif and the engineering-geological properties of the layers which are promising for the purpose. The following sites are investigated: 1) sites in one-type homogeneous rock massifs of high strength and elasticity; 2) sites of various type massifs with a promising layer of rocks with medium strength and elasticity; 3) sites in various type massifs with a promising layer of plastic rocks of low strength. It is concluded that the complexity of the geotechnical and other conditions in the territory of Bulgaria would predetermine the deficiency of the list of the properties required for the selected sites. The building up of engineering defence will be needed to offset that deficiency and their problems will be resolved after the specific site have been chosen. Geotechnical elements should be likewise envisaged within the general pattern of the monitoring needed. The designing, installing and putting into operation of the monitoring systems should be accomplished as early as the stage of the detailed investigation of the site selected. 19 refs., 2 suppls. (author)

Modeling of Zircaloy cladding degradation under repository conditions

International Nuclear Information System (INIS)

Santanam, L.; Raghavan, S.; Chin, B.A.

1989-07-01

Two potential degradation mechanisms, creep and stress corrosion cracking, of Zircaloy cladding during repository storage of spent nuclear fuel have been investigated. The deformation and fracture map methodology has been used to predict maximum allowable initial storage temperatures to achieve a thousand year life without rupture as a function of spent-fuel history. A stress analysis of fuel rods has been performed. Stresses in the outer zirconium oxide layer and the inner Zircaloy tube have been predicted for typical internal pressurization, oxide layer thickness, volume expansion from formation of the oxide layer and thermal expansion coefficients of the cladding and oxide. Stress relaxation occurring in-reactor has also been taken into account. The calculations indicate that for the anticipated storage conditions investigated, the outer zirconium oxide layer is in a state of compression thus making it unlikely that stress corrosion cracking of the exterior surface will occur. 20 refs., 6 figs., 9 tabs

Zircaloy cladding degradation under repository conditions

International Nuclear Information System (INIS)

Santanam, L.; Raghavan, S.; Chin, B.A.

1990-12-01

Creep, a potential degradation mechanism of Zircaloy cladding after repository disposal of spent nuclear fuel, has been investigated. The deformation and fracture map methodology has been used to predict maximum allowable initial storage temperatures to achieve a thousand year life without rupture as a function of spent-fuel history. Maximum allowable temperatures are 340 degree C (613 K) for typically stressed rods (70--100 MPa) and 300 degree C (573 K) for highly stressed rods (140--160 MPa). 10 refs., 2 figs

Corrosion of titanium and titanium alloys in spent fuel repository conditions - literature review

International Nuclear Information System (INIS)

Aho-Mantila, I.; Haenninen, H.; Aaltonen, P.; Taehtinen, S.

1985-03-01

The spent nuclear fuel is planned to be disposed in Finnish bedrock. The canister of spent fuel in waste repository is one barrier to the release of radionuclides. It is possible to choose a canister material with a known, measurable corrosion rate and to make it with thickness allowing corrosion to occur. The other possibility is to use a material which is nearly immune to general corrosion. In this second category there are titanium and titanium alloys which exhibit a very high degree of resistance to general corrosion. In this literature study the corrosion properties of unalloyed titanium, titanium alloyed with palladium and titanium alloyed with molybdenum and nickel are reviewed. The two titanium alloys own in addition to the excellent general corrosion properties outstanding properties against localized corrosion like pitting or crevice corrosion. Stress corrosion cracking and corrosion fatique of titanium seem not to be a problem in the repository conditions, but the possibilities of delayed cracking caused by hydrogen should be carefully appreciated. (author)

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

Long-term stability of the near-field about high-level radioactive waste repository in thermo-hydro-mechanical coupling action condition

International Nuclear Information System (INIS)

Liu Yuemiao; Wang Ju; Ke Dan; Cai Meifeng

2008-01-01

It is a long-term process for the high-level radioactive waste repository, from opening, construction to end of its service. The long-term stability of the near-field is the key issue for the design of HLW repository because the opening and heat generated from the HLW. Through a nationwide investigation, Beishan area, a Gobi desert in Gansu province, is considered as a suitable candidate and GMZ bentonite deposit which located in Xinghe County, Inner Mongolia has been proposed for the supplier of buffer/backfill material for HLW geological repository in China. According to the R and D guide of high-level radioactive waste disposal in China, the 3D model of HLW repository with high-level radioactive waste, canister and buffer/backfill material is established using FLAC3D. To take into account in situ stress, geothermal gradient, groundwater, thermal relief of HLW and swelling pressure of buffer/backfill material, the evolution of temperature, stress and displacement of HLW repository under thermo-mechanical coupling, hydro-mechanical coupling and thermo-hydro-mechanical coupling conditions was analyzed respectively. The long-term stability of HLW repository in Beishan area was studied. (authors)

Transfer systems in an underground repository

International Nuclear Information System (INIS)

Berg, H.P.; Ehrlich, D.

1991-01-01

In addition to logistic problem definitions taking into account the waste types of the wastes to be disposed of and the mining conditions, transport and handling of radioactive wastes in a repository, particularly require the keeping of safety technological marginal conditions mainly resulting from the accident analyses carried out. The realization of these safety technological aspects is described taking the planned Konrad repository as an example. (author)

Developing criteria to establish Trusted Digital Repositories

Science.gov (United States)

Faundeen, John L.

2017-01-01

This paper details the drivers, methods, and outcomes of the U.S. Geological Survey’s quest to establish criteria by which to judge its own digital preservation resources as Trusted Digital Repositories. Drivers included recent U.S. legislation focused on data and asset management conducted by federal agencies spending $100M USD or more annually on research activities. The methods entailed seeking existing evaluation criteria from national and international organizations such as International Standards Organization (ISO), U.S. Library of Congress, and Data Seal of Approval upon which to model USGS repository evaluations. Certification, complexity, cost, and usability of existing evaluation models were key considerations. The selected evaluation method was derived to allow the repository evaluation process to be transparent, understandable, and defensible; factors that are critical for judging competing, internal units. Implementing the chosen evaluation criteria involved establishing a cross-agency, multi-disciplinary team that interfaced across the organization. 

Institutional Repositories as Infrastructures for Long-Term Preservation

Science.gov (United States)

Francke, Helena; Gamalielsson, Jonas; Lundell, Björn

2017-01-01

Introduction: The study describes the conditions for long-term preservation of the content of the institutional repositories of Swedish higher education institutions based on an investigation of how deposited files are managed with regards to file format and how representatives of the repositories describe the functions of the repositories.…

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

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

Long-term durability experiments with concrete-based waste packages in simulated repository conditions

International Nuclear Information System (INIS)

Ipatti, A.

1993-03-01

Two extensive experiments on long-term durability of waste packages in simulated repository conditions are described. The first one is a 'half-scale experiment' comprising radioactive waste product and half-scale concrete containers in site specific groundwater conditions. The second one is 'full-scale experiment' including simulated inactive waste product and full-scale concrete container stored in slowly flowing fresh water. The scope of the experiments is to demonstrate long-term behaviour of the designed waste packages in contact with moderately concrete aggressive groundwater, and to evaluate the possible interactions between the waste product, concrete container and ground water. As the waste packages are made of high-quality concrete, provisions have been made to continue the experiments for several years

Geological boundary conditions for a safety demonstration and verification concept for a HLW repository in claystone in Germany. AnSichT

Energy Technology Data Exchange (ETDEWEB)

Stark, Lena; Bebiolka, Anke; Gerardi, Johannes [Federal Institute for Geosciences and Natural Resources (BGR), Hannover (Germany). Dept. of Underground Space for Storage and Economic Use; and others

2015-07-01

Within the framework of the R and D project ''AnSichT'', DBE TECHNOLOGY, BGR and GRS are developing a method to demonstrate the safety of a HLW repository in claystone in Germany. The methodological approach basing on a holistic concept, links the legal and geologic boundary conditions, the disposal and closure concept, the demonstration of barrier integrity, and the long-term analysis of the repository evolution as well. The geologic boundary conditions are specified by the description of the geological situation and generic models, the selection of representative parameters and geoscientific long-term predictions. They form a fundament for the system analysis.

Preliminary report on longevity of montmorillonite clay under repository-related conditions

International Nuclear Information System (INIS)

Pusch, R.; Karnland, O.

1990-12-01

This report summarizes current work on developing complete models for predicting the chemical stability of montmorillonitic bentonite buffer materials in HLW repositories. The major degrading mechanism is the conversion of montmorillonite to hydrous mica ('illite'), the basis of the derivation of tentative models being offered by ongoing systematic hydrothermal tests, which indicate that such conversion takes place by dissolution, yielding very mobile silica, and aluminium that tends to stay in the clay voids. The key mechanism in the transformation to hydrous mica at temperatures below about 130 degrees C is concluded to be neoformation of the latter mineral, the controlling parameter being the access to potassium. For temperatures ranging between 130 and 200 degrees C, excess silica is released by beidellitization and this yields I/S mixed layer minerals on uptake of potassium, and precipitation of cementing silica in the form of amorphous silica and cristobalite. The rate of transformation of montmorillonite to hydrous mica is still controlled by the access to potassium, i.e. by the rate at which potassium enters the clay. 10 Aa minerals that can be mistaken for hydrous mica can be formed by cementing collapsed stacks together. The models appear to give montmorillonite transformation rates that are in agreement with lab results and geological examples but further calibration, primarily by using the results of ongoing hydrothermal tests in the Stripa study, are required to make them applicable to repository conditions. (au)

Radioactive Waste Repositories and Incentives to Local Communities

International Nuclear Information System (INIS)

Knapp, A.; Medakovic, S.

2008-01-01

Public acceptance of radioactive waste (RW) repository depends on various and often community-specific factors. Although radiological risk from a properly constructed low and intermediate level waste (LILW) repository is practically negligible, routine safety considerations will favor low populated areas and therefore probably underdeveloped communities. Repository acceptance in such communities is more likely to be facilitated by prospective benefits to local economy, such as infrastructure development and increased employment, as well as by dedicated financial incentives to the community. Direct financial compensation to the local community for acceptance of the repository has been considered in some documents in countries experienced in RW management, but it has not become a widely accepted practice. In Croatia, a possibility for such compensation is mentioned in the land use plan in conjunction with the prospective RW repository site. In Slovenia, the government has already specified the annual amount of 2.33 million euro as a compensation for 'limited land use' to be shared by local communities in the vicinity of the planned LILW repository during its operation. Applicability of the Slovenian compensations to the prospective joint Slovenian-Croatian repository is not yet clear, at least in the aspect of joint funding. The joint Slovenian-Croatian Decommissioning and LILW and SF management program for NPP Krsko from 2004 did conservatively include the compensations into the repository cost estimates, but that might not be retained in subsequent revisions of the Program. According to the agreement between governments of Slovenia and Croatia on the Nuclear power plant Krsko, Croatian side has no obligations to participate in 'public expenditures' introduced after the agreement, as would be the case of community compensations for LILW repository in Slovenia. Before further decisions on joint NPP Krsko waste management are made, including the issue of LILW

Corrosion of container and infrastructure materials under clay repository conditions

International Nuclear Information System (INIS)

Debruyn, W.; Dresselaers, J.; Vermeiren, P.; Kelchtermans, J.; Tas, H.

1991-01-01

With regard to the disposal of high-level radioactive waste, it was recommended in a IAEA Technical Committee meeting to perform tests in realistic environments corresponding with normal and accidental conditions, to qualify and apply corrosion monitoring techniques for corrosion evaluation under real repository conditions and to develop corrosion and near-field evolution models. The actual Belgian experimental programme for the qualification of a container for long-term HLW storage in clay formations complies with these recommendations. The emphasis in the programme is indeed on in situ corrosion testing and monitoring and on in situ control of the near-field chemistry. Initial field experiments were performed in a near-surface clay quarry at Terhaegen. Based on a broad laboratory material screening programme and in agreement with the Commission of the European Communities, three reference materials were chosen for extensive in situ overpack testing. Ti/0.2 Pd and Hastelloy C-4 were chosen as reference corrosion resistant materials and a low-carbon steel as corrosion allowance reference material. This report summarizes progress made in the material qualification programme since the CEC contract of 1983-84. 57 Figs.; 15 Tabs.; 18 Refs

Preclosure radiological safety analysis for accident conditions of the potential Yucca Mountain Repository: Underground facilities; Yucca Mountain Site Characterization Project

Energy Technology Data Exchange (ETDEWEB)

Ma, C.W.; Sit, R.C.; Zavoshy, S.J.; Jardine, L.J. [Bechtel National, Inc., San Francisco, CA (United States); Laub, T.W. [Sandia National Labs., Albuquerque, NM (United States)

1992-06-01

This preliminary preclosure radiological safety analysis assesses the scenarios, probabilities, and potential radiological consequences associated with postulated accidents in the underground facility of the potential Yucca Mountain repository. The analysis follows a probabilistic-risk-assessment approach. Twenty-one event trees resulting in 129 accident scenarios are developed. Most of the scenarios have estimated annual probabilities ranging from 10{sup {minus}11}/yr to 10{sup {minus}5}/yr. The study identifies 33 scenarios that could result in offsite doses over 50 mrem and that have annual probabilities greater than 10{sup {minus}9}/yr. The largest offsite dose is calculated to be 220 mrem, which is less than the 500 mrem value used to define items important to safety in 10 CFR 60. The study does not address an estimate of uncertainties, therefore conclusions or decisions made as a result of this report should be made with caution.

Synthesis of tobermorite: A cement phase expected under repository conditions

International Nuclear Information System (INIS)

Martin, S.I.

1994-11-01

In this study I have synthesized tobermorite, Ca 5 Si 6 O l6 (OH) 2. 4H 2 0, a principal crystalline phase expected to form in cementitious materials subjected to elevated temperatures in a potential nuclear waste repository. Fluids interacting with these materials may have a profound effect on the integrity of the waste package and on transport of radionuclides. At ambient temperature, Portland cement reacts with water to form an amorphous calcium-silicate-hydrate (C-S-H) gel. At elevated temperatures, crystalline phases of various hydration states form. The C-S-H system has not been well characterized at elevated temperatures up to 250 degrees C, which has been considered a bounding temperature for the potential Yucca Mountain repository. Physical, chemical, and thermodynamic data for these cement minerals that are predicted to be stable at these temperatures must be obtained from synthetic or natural samples to help predict fluid chemistry. For some of these minerals natural samples are difficult to obtain in sufficient quantity and purity. Therefore, monomineralic phases must be synthesized in order to unambiguously define their behavior. The synthetic or natural phases will be characterized as part of a comprehensive study to define the behavior of cementitious materials in a repository environment

Modelling spent fuel and HLW behaviour in repository conditions

International Nuclear Information System (INIS)

Esparza, A. M.; Esteban, J. A.

2003-01-01

The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great statistics for have a representative dissolution rate, due at the number of experimental results is not very high and many of them show a great scatter, independently of theirs different compositions by axial and radial variations, due to linear power or local burnup. On the other hand, it is difficult to predict the spent fuel behaviour over the long term, based in short term experiments. In this report is given a little description of the radionuclides distribution in the spent fuel and also in the cladding/pellet gap, grain boundary, cracks and rim zones (the matrix rim zone can be considered with an especial characteristics very different to the rest of the spent fuel), and structural

Modelling spent fuel and HLW behaviour in repository conditions

Energy Technology Data Exchange (ETDEWEB)

Esparza, A M; Esteban, J A

2003-07-01

The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great statistics for have a representative dissolution rate, due at the number of experimental results is not very high and many of them show a great scatter, independently of theirs different compositions by axial and radial variations, due to linear power or local burnup. On the other hand, it is difficult to predict the spent fuel behaviour over the long term, based in short term experiments. In this report is given a little description of the radionuclides distribution in the spent fuel and also in the cladding/pellet gap, grain boundary, cracks and rim zones (the matrix rim zone can be considered with an especial characteristics very different to the rest of the spent fuel), and structural

Repository waste-handling operations, 1998

International Nuclear Information System (INIS)

Cottam, A.E.; Connell, L.

1986-04-01

The Civilian Radioactive Waste Management Program Mission Plan and the Generic Requirements for a Mined Geologic Disposal System state that beginning in 1998, commercial spent fuel not exceeding 70,000 metric tons of heavy metal, or a quantity of solidified high-level radioactive waste resulting from the reprocessing of such a quantity of spent fuel, will be shipped to a deep geologic repository for permanent storage. The development of a waste-handling system that can process 3000 metric tons of heavy metal annually will require the adoption of a fully automated approach. The safety and minimum exposure of personnel will be the prime goals of the repository waste handling system. A man-out-of-the-loop approach will be used in all operations including the receipt of spent fuel in shipping casks, the inspection and unloading of the spent fuel into automated hot-cell facilities, the disassembly of spent fuel assemblies, the consolidation of fuel rods, and the packaging of fuel rods into heavy-walled site-specific containers. These containers are designed to contain the radionuclides for up to 1000 years. The ability of a repository to handle more than 6000 pressurized water reactor spent-fuel rods per day on a production basis for approximately a 23-year period will require that a systems approach be adopted that combines space-age technology, robotics, and sophisticated automated computerized equipment. New advanced inspection techniques, maintenance by robots, and safety will be key factors in the design, construction, and licensing of a repository waste-handling facility for 1998

The Annual Condition of Education Report 2012

Science.gov (United States)

Iowa Department of Education, 2013

2013-01-01

The Annual Condition of Education Report provides a wide range of state-level data, including shifts in student populations and demographics, teacher salaries and characteristics, student achievement results, and school financial information. The report provides important metrics to the education community about the status of the education system.…

Experimental investigation of factors affecting the control of redox conditions within a radwaste repository

International Nuclear Information System (INIS)

Guppy, R.M.; Atkinson, A.

1991-04-01

The maximum aqueous concentration of multivalent radioelements in a radwaste repository can be estimated from the expected Eh (the oxidising or reducing tendency of the solution) and pH of the aqueous phase in the repository so long as equilibrium between all oxidising and reducing species can be guaranteed. The objective of the work reported here was to ascertain whether any significant departures from redox equilibrium are likely to arise. Technetium (VII) species were exposed under anaerobic conditions to concentrations of ferrous, hydrogen sulphide and thiosulphate species likely to be present in a repository environment to establish which species are capable of reducing aqueous Tc(VII) to a less soluble Tc(IV) solid compound. Potential catalytic solid phases and phases capable of electron exchange were also exposed to Tc(VII) species under anaerobic, aerobic and hydrogen atmospheres. We have not been able to demonstrate conclusively that mutual equilibrium was attained between technetium and iron redox couples, nor that the apparent solubility of technetium was that expected from the resulting Eh and pH of the solution, although some technetium was removed from solution. Hydrogen did not reduce Tc(VII) within the timescale of the experiments and no catalytic effects by haematite or a cementitious backfill grout for reductions involving hydrogen were observable. Magnetite removed some technetium from solution, apparently by surface reaction, under inert (argon) and reducing (hydrogen) atmospheres. Sulphides, and to a lesser extent thiosulphates, will reduce the solubility of technetium to a very low level. (author)

Making the Most of What We Have Got: Enhancing the RADAR Repository to Support Research Planning

Science.gov (United States)

Pike, Dawn; Siminson, Nicola Jane

2017-01-01

This article discusses how RADAR, the institutional repository (IR) at the Glasgow School of Art (GSA), has been modified to house an Annual Research Planning (ARP) template. A case study on the implementation of this research planning tool will outline the role that a repository and its staff can play in supporting individuals, enhancing…

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

SKB's safety case for a final repository license application

International Nuclear Information System (INIS)

Hedin, Allan; Andersson, Johan

2014-01-01

The safety assessment SR-Site is a main component in SKB's license application, submitted in March 2011, to construct and operate a final repository for spent nuclear fuel at Forsmark in the municipality of Oesthammar, Sweden. Its role in the application is to demonstrate long-term safety for a repository at Forsmark. The assessment relates to the KBS-3 disposal concept in which copper canisters with a cast iron insert containing spent nuclear fuel are surrounded by bentonite clay and deposited at approximately 500 m depth in saturated, granitic rock. The principal regulatory acceptance criterion, issued by the Swedish Radiation Safety Authority (SSM), requires that the annual risk of harmful effects after closure not exceed 10 -6 for a representative individual in the group exposed to the greatest risk. SSM's regulations also imply that the assessment time for a repository of this type is one million years after closure. The licence applied for is one in a stepwise series of permits, each requiring a safety report. The next step concerns a permit to start excavation of the repository and requires a preliminary safety assessment report (PSAR) covering both operational and post-closure safety. Later steps include permission to commence trial operation, to commence regular operation and to close the final repository. (authors)

The Annual Condition of Education Report, 2011

Science.gov (United States)

Iowa Department of Education, 2011

2011-01-01

The Annual Condition of Education Report provides a wide range of state-level data, including shifts in student populations and demographics, teacher salaries and characteristics, student achievement results, and school financial information. A few examples of the categories presented in this 22nd edition report include: (1) Enrollment; (2) Early…

Chemical durability of copper canisters under crystalline bedrock repository conditions

International Nuclear Information System (INIS)

Sjoeblom, R.; Hermansson, H.P.; Amcoff, Oe.

1995-01-01

In the Swedish waste management programme, the copper canister is expected to provide containment of the radionuclides for a very long time, perhaps million of years. The purpose of the present paper is to analyze prerequisites for assessments of corrosion lifetimes for copper canisters. The analysis is based on compilations of literature from the following areas: chemical literature on copper and copper corrosion, mineralogical literature with emphasis on the stability of copper in near surface environments, and chemical and mineralogical literature with emphasis on the stabilities and thermodynamics of species and phases that may exist in a repository environment. Three main types of situations are identified: (1) under oxidizing and low chloride conditions, passivating oxide type of layers may form on the copper surface; (2) under oxidizing and high chloride conditions, the species formed may all be dissolved; and (3) under reducing conditions, non-passivating sulfide type layers may form on the copper surface. Considerable variability and uncertainty exists regarding the chemical environment for the canister, especially in certain scenarios. Thus, the mechanisms for corrosion can be expected to differ greatly for different situations. The lifetime of a thick-walled copper canister subjected to general corrosion appears to be long for most reasonable chemistries. Localized corrosion may appear for types (1) and (3) above but the mechanisms are widely different in character. The penetration caused by localized corrosion can be expected to be very sensitive to details in the chemistry. 20 refs, 3 figs, 1 tab

Hydrological and hydrogeological effects of an open repository in Forsmark. Final MIKE SHE flow modelling results for the Environmental Impact Assessment

International Nuclear Information System (INIS)

Maartensson, Erik; Gustafsson, Lars-Goeran

2010-07-01

conditions show that the magnitude and the geographical extent of the groundwater-table drawdown are smaller than the hydraulic-head drawdown in the bedrock. The influence area for the groundwater-table drawdown primarily coincides with locations where the Quaternary deposits are in contact with bedrock containing fracture zones with high vertical hydraulic conductivity. The groundwater inflow to the repository, the groundwater-table drawdown and the drawdown of hydraulic heads in the bedrock were analysed for different values of the hydraulic conductivity of the grouted zone (K grout ) and also for layouts that aim to represent different repository-development phases. For a hypothetical case with a fully open repository, the model-calculated inflow is in the interval 15-47 L/s depending on the value of K grout . Using meteorological data and sea-level data for the year 2006, the associated influence area for the groundwater-table drawdown (annual average drawdown exceeding 0.3 m) has a size of 1.4 km 2 for K grout = 10 -7 m/s and less than half for K grout = 10 -9 m/s. According to the modelling results, the groundwater inflow to the repository has very small effects on water levels in lakes and discharges in streams. However, for K grout = 10 -7 m/s the annually accumulated discharge in the stream upstream from Lake Bolundsfjaerden is reduced by 13%, which is due to drawdown of the groundwater table within the catchment area of the stream. Sensitivity analyses show that the groundwater inflow to the repository and the size of the groundwater table influence area are not very sensitive to the tested variants concerning the hydrogeological properties of the upper 200 m of the bedrock and the boundary conditions (including the sea level). The model-calculated influence area demonstrates some sensitivity to the choice of methodology for modelling water flow in the unsaturated zone. Moreover, the influence area is larger if the hydrogeological properties in the upper 20 m of

Hydrological and hydrogeological effects of an open repository in Forsmark. Final MIKE SHE flow modelling results for the Environmental Impact Assessment

Energy Technology Data Exchange (ETDEWEB)

Maartensson, Erik; Gustafsson, Lars-Goeran (DHI Sverige AB (Sweden))

2010-07-15

conditions show that the magnitude and the geographical extent of the groundwater-table drawdown are smaller than the hydraulic-head drawdown in the bedrock. The influence area for the groundwater-table drawdown primarily coincides with locations where the Quaternary deposits are in contact with bedrock containing fracture zones with high vertical hydraulic conductivity. The groundwater inflow to the repository, the groundwater-table drawdown and the drawdown of hydraulic heads in the bedrock were analysed for different values of the hydraulic conductivity of the grouted zone (K{sub grout}) and also for layouts that aim to represent different repository-development phases. For a hypothetical case with a fully open repository, the model-calculated inflow is in the interval 15-47 L/s depending on the value of K{sub grout}. Using meteorological data and sea-level data for the year 2006, the associated influence area for the groundwater-table drawdown (annual average drawdown exceeding 0.3 m) has a size of 1.4 km2 for K{sub grout} = 10-7 m/s and less than half for K{sub grout} = 10-9 m/s. According to the modelling results, the groundwater inflow to the repository has very small effects on water levels in lakes and discharges in streams. However, for K{sub grout} = 10-7 m/s the annually accumulated discharge in the stream upstream from Lake Bolundsfjaerden is reduced by 13%, which is due to drawdown of the groundwater table within the catchment area of the stream. Sensitivity analyses show that the groundwater inflow to the repository and the size of the groundwater table influence area are not very sensitive to the tested variants concerning the hydrogeological properties of the upper 200 m of the bedrock and the boundary conditions (including the sea level). The model-calculated influence area demonstrates some sensitivity to the choice of methodology for modelling water flow in the unsaturated zone. Moreover, the influence area is larger if the hydrogeological properties in

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

Transient boundary conditions in the frame of THM-processes at nuclear waste repositories

Directory of Open Access Journals (Sweden)

Schanz Tom

2016-01-01

Full Text Available In nuclear waste repositories, initially unsaturated buffer is subjected to constant heat emitted by waste canister in conjunction with peripheral hydration through water from host rock. The transient hydration process can be potraied as transformation of initial heterogeneity towards homogeneity as final stage. In this context, this paper addresses the key issue of hydro mechanical behaviour of compacted buffer in context of clay microstructure and its evolution under repository relevant loading paths and material heterogeneity. This paper also introduces a unique column experiment facility available at Ruhr Universität Bochum, Germany. The facility has been designed as a forerunner of field scale testing program to simulate the transient hydration process of compacted buffer as per German reference disposal concept. The device is unique in terms of having proficiency to capture the transient material response under various possible repository relevant loading paths with higher precision level by monitor the key parameters like temperature, total suction, water content and axial & radial swelling pressure at three different sections along the length of compacted soil sample. In general, a larger spectrum of loading paths/scenarios, which may arise in the nuclear repository, can be covered precisely with existing device.

Progress report on the results of testing advanced conceptual design metal barrier materials under relevant environmental conditions for a tuff repository

International Nuclear Information System (INIS)

McCright, R.D.; Halsey, W.G.; Van Konynenburg, R.A.

1987-12-01

This report discusses the performance of candidate metallic materials envisioned for fabricating waste package containers for long-term disposal at a possible geological repository at Yucca Mountain, Nevada. Candidate materials include austenitic iron-base to nickel-base alloy (AISI 304L, AISI 316L, and Alloy 825), high-purity copper (CDA 102), and copper-base alloys (CDA 613 and CDA 715). Possible degradation modes affecting these container materials are identified in the context of anticipated environmental conditions at the repository site. Low-temperature oxidation is the dominant degradation mode over most of the time period of concern (minimum of 300 yr to a maximum of 1000 yr after repository closure), but various forms of aqueous corrosion will occur when water infiltrates into the near-package environment. The results of three years of experimental work in different repository-relevant environments are presented. Much of the work was performed in water taken from Well J-13, located near the repository, and some of the experiments included gamma irradiation of the water or vapor environment. The influence of metallurgical effects on the corrosion and oxidation resistance of the material is reviewed; these effects result from container fabrication, welding, and long-term aging at moderately elevated temperatures in the repository. The report indicates the need for mechanisms to understand the physical/chemical reactions that determine the nature and rate of the different degradation modes, and the subsequent need for models based on these mechanisms for projecting the long-term performance of the container from comparatively short-term laboratory data. 91 refs., 17 figs., 16 tabs

Localized corrosion of metallic materials and γ radiation effects in passive layers under simulated radwaste repository conditions. Final report

International Nuclear Information System (INIS)

Schultze, J.W.; Kudelka, S.; Michaelis, A.; Schweinsberg, M.; Thies, A.

1996-02-01

The task of the project was to simulate the conditions in a radwaste repository and to perform local analyses in order to detect the critical conditions and material susceptibilities leading to localized corrosion of materials. The information thus obtained was to yield more precise data on the long-term stability of materials for the intended purpose, in order to be able to appropriately select or optimize the materials (Ti, TiO.2Pd, Hastelloy C4, fine-grained structural steel). A major aspect to be examined was natural inhomogeneities of the electrode surfaces, as determined by the grain structure of the selected materials. Thus a laterally inhomogeneous composition in the welded zone induces an inhomogeneous current distribution, and hence strong susceptibility to localized corrosion. This effect was to be quantified, and the localized corrosion processes had to be identified by means of novel, electrochemical methods with a resolution power of μm. The investigations were to be made under conditions as near to practice as possible, for instance by simulating radwaste repository conditions and performing measurements at elevated temperatures (170 C) in an autoclave. Another task was to examine the radiation effects of γ radiation on passive layers, and describe the possible modifications induced by recrystallisation, photocorrosion, or oxide formation. (orig./MM) [de

Analysis on one underground nuclear waste repository rock mass in USA

International Nuclear Information System (INIS)

Ha Qiuling; Zhang Tiantian

2012-01-01

When analyzing the rock mass of a underground nuclear waste repository, the current studies are all based on the loading mechanical condition, and the unloading damage of rock mass is unconsidered. According to the different mechanical condition of actual engineering rock mass of loading and unloading, this paper implements a comprehensive analysis on the rock mass deformation of underground nuclear waste repository through the combination of present loading and unloading rock mass mechanics. It is found that the results of comprehensive analysis and actual measured data on the rock mass deformation of underground nuclear waste repository are basically the same, which provide supporting data for the underground nuclear waste repository. (authors)

Basalt Waste Isolation Project. Annual report, fiscal year 1979

International Nuclear Information System (INIS)

1979-11-01

This project is aimed at examining the feasibility and providing the technology to design and construct a radwaste repository in basalt formations beneath and within the Hanford Site. The project is divided into seven areas: systems integration, geosciences, hydrologic studies, engineered barriers, near-surface test facility, engineering testing, and repository engineering. This annual report summarizes key investigations in these seven areas

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

Long-term degradation of organic polymers under conditions found in deep repositories for low and intermediate-level wastes; Langzeit-Degradation von organischen Polymeren unter SMA-Tiefenlagerbedingungen

Energy Technology Data Exchange (ETDEWEB)

Warthmann, R.; Mosberger, L.; Baier, U.

2013-06-15

On behalf of Nagra, the Environmental Biotechnology Section of the Zürich University of Applied Sciences in Wädenswil investigated the potential for microbiological degradation of organic polymers under the conditions found in a deep geological repository for low- and intermediate-level waste (L/ILW). The existing scientific literature on the topic was analysed, some thermodynamic calculations carried out and input was elicited from internationally recognised experts in the field. The study was restricted to a few substances which, in terms of mass, are most significant in the Swiss L/ILW inventory; these are polystyrene (PS), polyvinyl chloride (PVC), other plastics and bitumen. There were no clear indications in the literature that the polymer structure of synthetic polymers is biodegraded under anoxic conditions. However, functional groups of ion exchangers and plasticizers in plastics are considered to be readily available and biodegradable. The greatest obstacle to biological degradation of synthetic polymers is depolymerisation to produce labile monomers. As energy is generally required for such breakdown, the chances of this process taking place outside the cells are very low. In so far as they are present, monomers are, in principle, anaerobically biodegradable. Thermodynamic considerations indicate that degradation of synthetic polymers under repository conditions is theoretically possible. However, the degradation of polystyrene is very close to thermodynamic equilibrium and the usable energy for microorganisms would barely be sufficient. Under high H2 partial pressures, it is predicted that there will be a thermodynamic inhibition of anaerobic degradation, as certain interim steps in degradation are endergonic. The starting conditions for microbial growth in a deep repository are unfavourable in terms of availability of water and prevailing pH values. Practically no known microorganisms can tolerate the combination of these conditions; most known

Safety case for Slovenian LILW near-surface repository

International Nuclear Information System (INIS)

Viršek, Sandi; Špiler, Janja; Žagar, Tomaž

2016-01-01

Conclusions: • Repository provides the fulfillment of international and national legal requirements regarding treatment and disposal of LILW; • Repository improves the conditions for life extension for NPP Krško and offers synergetic effects for the second unit of NPP Krško; • Repository provides a basis for safe, economic and reliable use of radioactive sources in science, medicine and industry in Slovenia; • All economic calculations and comparisons show a clear advantage in case of a joint Slovenian and Croatian solution

Reactive transport predictions for an Olkiluoto. Final repository tunnel unit

International Nuclear Information System (INIS)

Luukkonen, A.; Nordman, H.

2007-09-01

The presented hydrogeochemical reactive transport calculations concentrate to a defined unit piece (unit cell) of the planned Olkiluoto repository that is under design for spent nuclear fuel. The material properties assigned to the tunnel unit are based on literature as far as possible. Calculations make up geochemical future scenarios on the repository evolution. Most recent predictions on the potential future climate at Olkiluoto are utilised together with estimates how future hydraulic conditions affect the repository. Two climate scenarios are considered in detail. The Weichselian-R scenario is based on the repetition of the last glacial cycle, while the Emissions-M scenario attempts to predict the future groundwater conditions at Olkiluoto in the situation where the atmospheric greenhouse gasses delay the next glacial cycle at least for 100,000 years. The groundwater compositions, considered active at the repository depth in future, are judged in this study. Several geochemical processes are considered active at the repository depth. Calculations concentrate on the changes occurring with time within the tunnel unit. All simulations are done in geochemically reducing conditions. It turns out that sulphur cycling in these conditions is in central role considering the safety assessment studies of Olkiluoto repository. Furthermore, groundwater salinity and cation occupancy within the exchange sites of montmorillonite contributes to sealing properties of the engineered barrier system. Calculations attempt to estimate effects of possible future scenarios for the Olkiluoto repository. The results indicate that the buffer capacities assigned to the tunnel unit are large enough, at least to next 100,000 years, to maintain dissolved sulphide contents low in the groundwater infiltrating through the tunnel engineered barrier system. Geochemical reactions raise the bicarbonate levels within the groundwater. This is a useful buffer if low pH conditions emerge in the

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

Logistics characterization for regional spent fuel repositories concept

International Nuclear Information System (INIS)

Joy, D.S.; Hudson, B.J.; Anthony, M.W.

1980-08-01

This report summarizes a study of logistics considerations for a four-region repository system for spent fuel disposal. The logistics considerations include: (1) yearly receipt and emplacement; (2) inventory; (3) away-from-reactor (AFR) storage; (4) nuclear capacity growth effects; (5) entire lifetime of reactors served by repository operations; (6) proportions of pressurized-water-reactor (PWR)/boiling-water-reactor (BWR) fuel; (7) proportions of rail and truck shipments; (8) shipping cask fleet requirements; (9) number of annual shipments; (10) mode (rail/truck) and cost of shipment; and (11) initial year for shipment to maintain full core reserve. The nation was divided into Northeast, North Central, Southern, and Western regions for evaluation purposes. Repository logistics were analyzed in each region based on three different capacity projections. For the Southern region, results for seven salt dome sites are presented. The Western region results cover four potential sites. The North Central and Northeastern regions results are not presented on a site specific basis. Conclusions are drawn based on the results. The methodology assumptions and references used in the logistics analysis are described for the convenience of the reader

Implications of one-year basalt weathering/reactivity study for a basalt repository environment

International Nuclear Information System (INIS)

Pine, G.L.; Jantzen, C.M.

1987-03-01

The Savannah River Laboratory is testing the performance of the Defense Waste Processing Facility glass under conditions representing potential repository environments. For a basalt repository, one of the important issues is how rapidly reducing conditions are re-established after placement of the waste. The objective of this study was to examine the factors affecting the reactivity of the basalt. Construction of a nuclear waste repository in basalt will temporarily perturb the groundwater conditions, creating more oxidizing (air-saturated) conditions than an undisturbed repository system. Reducing conditions can be beneficial to the performance of waste glass and canisters, and may limit the transport of certain radionuclides. The Basalt Waste Isolation Project intends to use a backfill containing crushed basalt to re-establish the reducing conditions of the groundwater. The reactivity of the basalt has been found to be minimal once the fresh crushed surfaces have been weathered and the reactive intergranular glass component has been leached, e.g., by long-term surface storage. Crushing of the basalt for pneumatic emplacement of the backfill should, therefore, occur shortly before placement in the repository. This backfill must contain a minimum of 5 percent reactive fines (<100 mesh), to rapidly achieve reducing conditions. 23 refs., 21 figs., 18 tabs

Old waste products - new requirements. Preparations for the later repository

International Nuclear Information System (INIS)

Graf, A.; Merx, H.

2003-01-01

For more than 30 years now, the Hauptabteilung Dekontaminationsbetriebe (HDB, Central Decontamination Department) of the Forschungszentrum Karlsruhe has been engaged in the management of radioactive wastes produced by the operation and decommissioning of research reactors and institutes of the Research Center, the Karlsruhe reprocessing plant, the European Institute for Transuranium Elements, and the Baden-Wuerttemberg state collection center. For this purpose, the wastes delivered to HDB have been conditioned at various facilities according to the requirements specified. These conditioning requirements, however, have changed in the course of time. In the past, only minimum declaration and conditioning requirements had to be fulfilled for the ASSE repository storage facility. Since 1994, the KONRAD repository storage conditions have been adopted. They comprise a variety of quality criteria. Judging from today, duration of interim storage until transfer to a repository storage facility will take another 30 years at least. In addition to the documentary qualification of the waste products, it is therefore required to take measures to ensure long-term safety of both the waste packages and their storage. This is why the HDB, in agreement with the supervisory authority, i.e. the Federal Radiation Protection Authority, and its experts, has decided to put the waste products into KONRAD containers in certified compliance with the repository storage conditions and to backfill these containers with concrete in accordance with approved procedures. Thus, waste packages suited for repository storage will be produced and corrosion processes and the possible release of radioactivity will be prevented. (orig.)

Old waste products - new requirements. Preparations for the later repository

Energy Technology Data Exchange (ETDEWEB)

Graf, A.; Merx, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Hauptabteilung Dekontaminationsbetriebe

2003-07-01

For more than 30 years now, the Hauptabteilung Dekontaminationsbetriebe (HDB, Central Decontamination Department) of the Forschungszentrum Karlsruhe has been engaged in the management of radioactive wastes produced by the operation and decommissioning of research reactors and institutes of the Research Center, the Karlsruhe reprocessing plant, the European Institute for Transuranium Elements, and the Baden-Wuerttemberg state collection center. For this purpose, the wastes delivered to HDB have been conditioned at various facilities according to the requirements specified. These conditioning requirements, however, have changed in the course of time. In the past, only minimum declaration and conditioning requirements had to be fulfilled for the ASSE repository storage facility. Since 1994, the KONRAD repository storage conditions have been adopted. They comprise a variety of quality criteria. Judging from today, duration of interim storage until transfer to a repository storage facility will take another 30 years at least. In addition to the documentary qualification of the waste products, it is therefore required to take measures to ensure long-term safety of both the waste packages and their storage. This is why the HDB, in agreement with the supervisory authority, i.e. the Federal Radiation Protection Authority, and its experts, has decided to put the waste products into KONRAD containers in certified compliance with the repository storage conditions and to backfill these containers with concrete in accordance with approved procedures. Thus, waste packages suited for repository storage will be produced and corrosion processes and the possible release of radioactivity will be prevented. (orig.)

Status of LANL investigations of temperature constraints on clay in repository environments

International Nuclear Information System (INIS)

Caporuscio, Florie A.; Cheshire, Michael C.; Newell, Dennis L.; McCarney, Mary Kate

2012-01-01

The Used Fuel Disposition (UFD) Campaign is presently evaluating various generic options for disposal of used fuel. The focus of this experimental work is to characterize and bound Engineered Barrier Systems (EBS) conditions in high heat load repositories. The UFD now has the ability to evaluate multiple EBS materials, waste containers, and rock types at higher heat loads and pressures (including deep boreholes). The geologic conditions now available to the U.S.A. and the international community for repositories include saturated and reduced water conditions, along with higher pressure and temperature (P, T) regimes. Chemical and structural changes to the clays, in either backfill/buffer or clay-rich host rock, may have significant effects on repository evolution. Reduction of smectite expansion capacity and rehydration potential due to heating could affect the isolation provided by EBS. Processes such as cementation by silica precipitation and authigenic illite could change the hydraulic and mechanical properties of clay-rich materials. Experimental studies of these repository conditions at high P,T have not been performed in the U.S. for decades and little has been done by the international community at high P,T. The experiments to be performed by LANL will focus on the importance of repository chemical and mineralogical conditions at elevated P,T conditions. This will provide input to the assessment of scientific basis for elevating the temperature limits in clay barriers.

Radionuclide getters in the near-field chemistry of repositories

International Nuclear Information System (INIS)

Holland, T.R.; Lee, D.J.

1993-01-01

The ultimate release of radionuclides from a radioactive waste repository will depend upon the natural and man-made barriers surrounding the site. An opportunity exists to enhance natural radionuclide retention through improved sorption, by the use of suitable additives applied to the repository backfill material. This programme of work was designed to identify problem isotopes, to search for suitable materials to enhance their retention and ultimately to provide, through experimental studies, an understanding of their effectiveness under repository conditions. (Author)

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.

Management of radioactive waste at Novi Han Repository

International Nuclear Information System (INIS)

Stefanova, I.G.; Mateeva, M.D.; Milanov, M.V.

2002-01-01

The Novi Han Repository is the only existing repository in Bulgaria for the disposal of radioactive waste from nuclear applications in industry, medicine and research. The repository was constructed in the early sixties according to the existing requirements. It was operated by the Institute for Nuclear Research and Nuclear Energy for more than thirty years without any accident or release of radioactivity to the environment, but without any investment for upgrading. As a consequence, the Bulgarian Nuclear Safety Authority temporarily stopped the operation of the repository in 1994. The measures for upgrading the Novi Han Repository, supported by the IAEA under TC Project BUL/4/005 'Increasing Safety of Novi Han Repository', are presented in this paper. They comprise: assessment of radionuclide inventory and future waste arisings, characterisation of disposal vaults, characterisation of the site, safety assessment, upgrading of the monitoring system, option study for the selection of treatment and conditioning processes and the development of a conceptual design for low and intermediate level waste processing and storage facility, immediate measures for improvement of the existing disposal vaults and infrastructure, construction of above-ground temporary storage structures, and resuming the operation of the Novi Han Repository. The necessary activities for re-licensing of the Novi Han Repository, construction of a waste processing and storage facility and a disposal facility for spent sealed sources are discussed. (author)

Evaluation on radiation protection aspect and radiological risk at Mukim Belanja repository

Energy Technology Data Exchange (ETDEWEB)

Azmi, Siti Nur Aisyah, E-mail: nuclear.aisyahazmi@gmail.com; Kenoh, Hamiza; Majid, Amran Ab. [Nuclear Technology Research Centre, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

2016-01-22

Asian Rare Earth (ARE) is a locally incorporated company that operated a mineral processing operation to extract rare earth element. ARE has received much attention from the public since the beginning of their operation until the work of decommissioning and decontamination of the plant. Due to the existence of Naturally Occurring Radioactive Material (NORM) in the residue, the decommissioning and disposal was done by the company in collaboration with the Perak State Government and the Atomic Energy Licensing Board (AELB). The main objective of this study is to review the level of compliance of the existing Radiation Protection Regulations enforced by AELB particularly in the achievement of allowed exposure dose limit. The next objective was to study the impact of the construction of the Mukim Belanja Repository to workers and public. This study was conducted by analyzing documents that were issued and conducting the area monitoring using a Geiger Muller detector (GM) and Sodium Iodide (NaI(Tl)) survey meters. The measurements were made at 5 cm and 1 m from the ground surface at 27 measurement stations. The external doses measured were within the background levels of the surrounding area. The annual effective dose using the highest reading at 5 cm and 1 m from ground surface by GM detector was calculated to be 1.36 mSv/year and 1.21 mSv/year respectively. Whereas the annual effective dose using the highest reading at 5 cm and 1 m from ground surface by using NaI(Tl) detector was calculated to be 3.31 mSv/year and 2.83 mSv/year respectively. The calculated cancer risks from the study showed that the risk is small compared with the risks derived from natural radiation based on global annual radiation dose to humans. This study therefore indicated that the repository is able to constrain the dose exposure from the disposed NORM waste. The study also revealed that the construction of the repository has complied with all the rules and regulations subjected to

Microbial corrosion of metallic materials in a deep nuclear-waste repository

Directory of Open Access Journals (Sweden)

Stoulil J.

2016-06-01

Full Text Available The study summarises current knowledge on microbial corrosion in a deep nuclear-waste repository. The first part evaluates the general impact of microbial activity on corrosion mechanisms. Especially, the impact of microbial metabolism on the environment and the impact of biofilms on the surface of structure materials were evaluated. The next part focuses on microbial corrosion in a deep nuclear-waste repository. The study aims to suggest the development of the repository environment and in that respect the viability of bacteria, depending on the probable conditions of the environment, such as humidity of bentonite, pressure in compact bentonite, the impact of ionizing radiation, etc. The last part is aimed at possible techniques for microbial corrosion mechanism monitoring in the conditions of a deep repository. Namely, electrochemical and microscopic techniques were discussed.

Thermal management and analysis for a potential yucca mountain repository

International Nuclear Information System (INIS)

Van Luik, A.

2005-01-01

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. 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 includes a summary of the technical basis that supports these evaluations. The majority of the material

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

Average monthly and annual climate maps for Bolivia

KAUST Repository

Vicente-Serrano, Sergio M.

2015-02-24

This study presents monthly and annual climate maps for relevant hydroclimatic variables in Bolivia. We used the most complete network of precipitation and temperature stations available in Bolivia, which passed a careful quality control and temporal homogenization procedure. Monthly average maps at the spatial resolution of 1 km were modeled by means of a regression-based approach using topographic and geographic variables as predictors. The monthly average maximum and minimum temperatures, precipitation and potential exoatmospheric solar radiation under clear sky conditions are used to estimate the monthly average atmospheric evaporative demand by means of the Hargreaves model. Finally, the average water balance is estimated on a monthly and annual scale for each 1 km cell by means of the difference between precipitation and atmospheric evaporative demand. The digital layers used to create the maps are available in the digital repository of the Spanish National Research Council.

Creep of OFHC and silver copper at simulated final repository canister-service conditions

International Nuclear Information System (INIS)

Auerkari, P.; Leinonen, H.; Sandlin, S.

1991-07-01

Result of high-resolution creep rate measurements are described for estimating very long term creep life of copper and silver alloyed copper at room temperature and at stresses approaching the expected service conditions of final repository canisters. The aim was to assess the limiting service stress levels for potential canister wall materials. The 0.1 % silver alloyed copper showed minimum creep rates of 10 - 9 to 10 - 10 l/h, corresponding to 1 % strain in about 1000 to 10000 years, at room temperature and uniaxial stress level of 50 to 75 MPa. The predicted time to 1 % strain, when extrapolated from literature data, was at least one order of magnitude shorter. From the results of the present work, the 1 % creep life for OFHC copper was at most a few hundreds of years at 50 MPa stress level. The technique developed and used in this work for measuring very low strain rates appears useful for assessing low temperature creep life of practical structures essentially without accelerating the test from the service conditions

Creep of OFHC and silver copper at simulated final repository canister-service conditions

International Nuclear Information System (INIS)

Auerkari, P.; Leinonen, H.; Sandlin, S.

1991-09-01

Results of high-resolution creep rate measurements are described for estimating very long term creep life of copper and silver alloyed copper at room temperature and at stresses approaching the expected service conditions of final repository canisters. The aim was to assess the limiting service stress levels for potential canister wall materials. The 0.1% silver alloyed copper showed minimum creep rates of 10 -9 to 10 -10 l/h, corresponding to 1 % strain in about 1000 to 10000 years, at room temperature and uniaxial stress level of 50 to 75 MPa. The predicted time to 1 % strain, when extrapolated from literature data, was at least one order of magnitude shorter. From the results of the present work, the 1 % creep life for OFHC copper was at most a few hundreds of years at 50 MPa stress level. The technique developed and used in this work for measuring very low strain rates appears useful for assessing low temperature creep life of practical structures essentially without accelerating the test from the service conditions. (au)

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.)

TURVA-2012: Assessment of radionuclide release scenarios for the repository system

International Nuclear Information System (INIS)

Smith, Paul; Poteri, Antti; Nordman, Henrik; Cormenzana, Jose Luis; Snellman, Margit; Marcos, Nuria; Hjerpe, Thomas; Koskinen, Lasse

2014-01-01

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the analyses of the radionuclide release scenarios formulated in a companion paper, TURVA-2012: Formulation of Radionuclide Release Scenarios (Marcos, 2014). The scenarios and the analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in a further paper: TURVA-2012: Performance Assessment (Hellae, 2014). For each scenario, calculation cases are analysed to evaluate compliance of the proposed repository with regulatory requirements on radiological protection, as well as to illustrate the impact of specific uncertainties or combinations of uncertainties on the calculated results. Each case illustrates different possibilities for how the repository might evolve and perform over time, taking into account uncertainties in the models and parameter values used to represent radionuclide release, retention and transport and, for biosphere assessment calculation cases, radiation exposure. The calculation cases each address a single, failed canister, where three possible modes of failure are considered: - The presence of an initial defect in the copper overpack of the canister that penetrates the overpack completely (subsequent corrosion of the insert may then lead to an enlargement of the defect). - Corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion. - Shear movements on fractures intersecting the deposition holes. However, the likelihood and consequences of more than one canister failure occurring during the assessment time fame are also considered, generally based on the findings from the single canister calculations. Quantitative

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

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.

Diversion path analysis for the Swedish geological repository

International Nuclear Information System (INIS)

Fritzell, Anni; Meer, Klaas Van Der

2008-02-01

The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

Diversion path analysis for the Swedish geological repository

Energy Technology Data Exchange (ETDEWEB)

Fritzell, Anni (Dept. of Physics and Astronomy, Uppsala Univ., Uppsala (Sweden)); Meer, Klaas Van Der (Belgian Nuclear Research Center SCK.CEN (BG))

2008-02-15

The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

Expert and non-expert groups perception of LILW repository site selection procedure

International Nuclear Information System (INIS)

Zeleznik, N.; Polic, M.

2001-01-01

Slovenia is now in the process of the site selection for a low and intermediate level radioactive waste (LILW) repository. Earlier searches for the LILW repository site confronted the Agency for radwaste management (ARAO) with a number of problems, mainly concerning the contacts with the local communities and their willingness to accept the repository. Therefore the Agency started with a new, so-called mixed mode approach to the site selection, where the special role of a mediator is introduced. The mediator represents the link between the investor and the local community, and facilitates the communication and negotiations between both. In this study we try to find out how people perceive the mediating process and conditions under which the LILW repository would be accepted in the local community. Therefore a special survey was conducted. The results showed some of the conditions under which participants would possibly accept the LILW repository. Differences in the perception between non-expert and expert groups were demonstrated and analysed, especially in the assessment of the consequences of LILW repository construction on the environment. Also the socio-psychological influences of the LILW repository were noted and examined. Consequences and recommendations for future work on the site selection procedure were prepared on the basis of the research results.(author)

Time evolution of dissolved oxygen and redox conditions in a HLW repository

International Nuclear Information System (INIS)

Wersin, P.; Spahiu, K.; Bruno, J.

1994-02-01

The evolution of oxygen in a HLW repository has been studied using presently available geochemical background information. The important processes affecting oxygen migration in the near-field include diffusion and oxidation of pyrite and dissolved Fe(II). The evaluation of time scales of oxygen decrease is carried out with 1. an analytical approach involving the coupling of diffusion and chemical reaction, 2. a numerical geochemical approach involving the application of a newly developed diffusion-extended version of the STEADYQL code. Both approaches yield consistent rates of oxygen decrease and indicate that oxidation of pyrite impurities in the clay is the dominant process. The results obtained fRom geochemical modelling are interpreted in terms of evolution of redox conditions. Moreover, a sensitivity analysis of the major geochemical and physical parameters is performed. These results indicate that the uncertainties associated with reactive pyrite surface area impose the overall uncertainties of prediction of time scales. Thus, the obtained time of decrease to 1% of initial O 2 concentrations range between 7 and 290 years. The elapsed time at which the transition to anoxic conditions occurs is estimated to be within the same time range. Additional experimental information on redox sensitive impurities in the envisioned buffer and backfill material would further constrain the evaluated time scales. 41 refs

Experimental conditions and monitoring items of the prototype repository project (PRP). Research document

International Nuclear Information System (INIS)

Sugita, Yutaka; Ito, Akira; Kawakami, Susumu

2003-03-01

Various experiments are ongoing in the underground research facility 'the Hard Rock Laboratory (HRL)' of SKB in Sweden for the geological disposal of the high-level radioactive waste. International joint project Prototype Repository Project (PRP) is one of the experiments in the HRL which has some engineered barrier systems and to study the coupled behavior happening in and around the engineered barrier system. JNC has joined this international joint project PRP to obtain the information of the coupled behavior on such systematic engineered barrier system and to apply the JNC's coupled THMC analytical code to the prediction and back analysis of the PRP. The analytical code will be verified through these analyses in this project. JNC can apply the verified analytical code to assess the coupled behavior in Japan. This report summarizes the experimental conditions and monitoring items of the PRP. (author)

EEI/UWASTE oversight of the DOE Repository Program by the Repository Information Exchange Team

International Nuclear Information System (INIS)

Henkel, C.J.; Supko, E.M.; Schwartz, M.H.

1993-01-01

The Utility Nuclear Waste and Transportation Program of the Edison Electric Institute (EEI/UWASTE) has conducted reviews of the US DOE's repository program through its Repository Information Exchange Team (RIET or Team). Eight such reviews have been conducted since 1985 covering topics that include repository program management and control; repository schedule; repository budget; quality assurance; site characterization; repository licensing; environmental issues; and institutional and public information activities. The utility industry has used these repository program reviews as a forum for providing DOE's Office of Civilian Radioactive Waste Management (OCRWM) with comments on the direction of the repository program, advice for future actions regarding quality assurance activities and repository licensing, and suggestions for management and control of the Repository Program. The most significant recommendations made by the utility industry through the RIET are discussed along with any subsequent action by OCRWM in response to or subsequent to utility industry recommendations. The process used by the RIET to develop its recommendations to OCRWM regarding the repository program is also discussed

Development of a central final repository management for the coordination of the waste for Schacht Konrad from public authorities

International Nuclear Information System (INIS)

Graffunder, Iris; Dominke-Bendix, Carola; Waldek, Achim

2012-01-01

The central final repository management is supposed to fulfill the following tasks: active collaboration of Konrad contract draft, signing of internal contracts and agreements, cooperation contract with GNS, cooperation with coordination authorities, inventory taking of wastes (existing inventory and prognosis) and interim storage capacities of public authorities, development of planning and management software, optimization of the final repository documentation, container management, logistics concept, long-term disposal planning and prognosis, planning and coordination of the annual waste amount, management and documentation of disposed waste allocation, coordination of transport schedules, consulting service for waste obligations (final repository requirements, product control, documentation).

Experimental and modelling studies of the near-field chemistry for Nirex repository concepts

International Nuclear Information System (INIS)

Atkinson, A.; Ewart, F.T.; Pugh, S.Y.R.; Rees, J.H.; Sharland, S.M.; Tasker, P.W.; Wilkins, J.D.

1988-02-01

A research programme is described which is designed to investigate the chemical conditions in the near field of a concrete based repository and the behaviour of the radiologically important nuclides under these conditions. The chemical conditions are determined by the corrosion of the iron components of the repository and by the soluble components of the concrete. Both of these have been investigated experimentally and models developed which have been validated by further experiment. The effect of these reactions on the repository pH and Eh, and how these develop in time and space have been modelled using a coupled chemical equilibrium and transport code. The solubility of the important nuclides are being studied experimentally under these conditions, and under sensible variations. These data have been used to refine the thermodynamic data base used for the geochemical code PHREEQE. The sorption behaviour of plutonium and americium, under the same conditions, have been studied; the sorption coefficients were found to be large and independent of the concrete formulation, particle size and solid liquid ratio. Recent experimental results from sorption/exchange experiments with lead and 14-carbon are also reported. The programme has also investigated experimentally the possible perturbation of the repository chemistry by microbial action and by natural and added organic material. A final set of experiments combine all the repository components and the waste in a long term equilibration experiment. (author)

General construction requirements for the deep repository in the KBS-3 system

International Nuclear Information System (INIS)

2002-10-01

The KBS-3 systems includes equipment and plants for transport of spent nuclear fuels and encapsulated spent fuels, central intermediate storage, encapsulation and deep geologic disposal. The requirements in this document concern the repository and have been put together in view of the tasks of designing, constructing and building the repository. The report presents: A general review of existing design plans; Laws and regulations relevant for the design of the repository; How the regulations have been broken down to functional demands and dimensioning requirements for the repository; How the site conditions influence the design, and how the layout of the different parts of the repository interact; Relations between the functions of the repository, the safety and the design; A foundation for developing construction plans for the repository. The requirements will be collected in a database that will develop as new knowledge is collected

Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

Science.gov (United States)

Rodríguez, Martín A.

2014-03-01

Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

The waste isolation pilot plant transuranic waste repository: A case study in radioactive waste disposal safety and risk

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Leif G. [GRAM, Inc., Albuquerque, NM (United States)

1999-12-01

The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk.

The waste isolation pilot plant transuranic waste repository: A case study in radioactive waste disposal safety and risk

International Nuclear Information System (INIS)

Eriksson, Leif G.

1999-01-01

The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk

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)

Repository relevant testing applied to the Yucca Mountain Project

International Nuclear Information System (INIS)

Bates, J.K.; Woodland, A.B.; Wronkiewicz, D.J.; Cunnane, J.C.

1990-10-01

The tuff beds of Yucca Mountain, Nevada, are currently being investigated as a site for the disposal of high-level nuclear waste in an underground repository. If this site is found suitable, the repository would be located in the unsaturated zone above the water table, and a description of the site and the methodology of assessing the performance of the repository are described in the Site Characterization Plan (SCP). While many factors are accounted for during performance assessment, an important input parameter is the degradation behavior of the waste forms, which may be either spent fuel or reprocessed waste contained in a borosilicate glass matrix. To develop the necessary waste form degradation input, the waste package environment needs to be identified. This environment will change as the waste decays and also is a function of the repository design which has not yet been finalized. At the present time, an exact description of the waste package environment is not available. The SCP does provide an initial description of conditions that can be used to guide waste form evaluation. However, considerable uncertainty exists concerning the conditions under which waste form degradation and radionuclide release may occur after the waste package containment barriers are finally breached. The release conditions that are considered to be plausible include (1) a open-quotes bathtubclose quotes condition in which the waste becomes fully or partially submerged in water that enters the breached container and accumulates to fill the container up to the level of the breach opening, (2) a open-quotes wet dripclose quotes or open-quotes trickle throughclose quotes condition in which the waste form is exposed to dripping water that enters through the top and exits the bottom of a container with multiple holes, and (3) a open-quotes dryclose quotes condition in which the waste form is exposed to a humid air environment

Autogenous healing of cracks in concrete and its relevance to radwaste repositories

International Nuclear Information System (INIS)

Guppy, R.

1988-03-01

Cracks in concrete structures within a radioactive waste repository could provide fast transport pathways and as such could impair the performance of the concrete as a barrier to radionuclide migration. It has been widely reported that cracks in concrete can heal and, therefore, the evidence in support of this phenomenon has been reviewed and its relevance to a concrete barrier in a radioactive waste repository assessed. The mechanism of crack healing is not understood, but the most likely process responsible is calcite formation under wet conditions. There is doubt concerning whether the conditions in a repository will be suitable for crack healing; especially if the cement is extensively modified with slag or fuel ash. It is concluded that further experimental work is required to assess the impact of this phenomenon on the behaviour of cracks in repositories. (author)

The Morsleben radwaste repository. Preparing for decommissioning

International Nuclear Information System (INIS)

Mehnert, M.; Schmitt, R.

2001-06-01

The publication is intended to illustrate with a brief chronology the history and the present situation of the Morsleben radwaste repository, including specific aspects such as the geology of the site and construction and engineering activities, the particulars of waste form emplacement and log-term storage conditions, topical issues relating to radiological safety during operation and after decommissioning. The brochure is designed for the general audience interested in background information on all aspects of the uses, operation and decommissioning of a radwaste repository in Germany. (orig./CB) [de

The main demands and criteria for building site choice for radioactive waste repositories

International Nuclear Information System (INIS)

Angelova, R.; Sandul, G.A.; Sen'ko, T.Ya.

2002-01-01

There are considered the main demands of building site choice for RAW repositories. At this the accent is placed on geological repositories (underground repositories of geological type) and near surface repositories assigned to disposal of low- and intermediate-level short- and mediate-lived radionuclides. These demands are conditionally separated into two blocks: account of social development of the adjoining territories; account of natural factors characterizing building site. Further there are discussed the questions of anthropogenous influence on a safety functioning of RAW repositories and of urgency of stable development of the adjoining territories. In context of the Ukrainian and other states nuclear laws there is also considered the lawful aspect defining the building site choice for RAW repositories

Analysis on regional hydrogeological condition of Beishan preselected area for high level radioactive waste disposal repository in Gansu province

International Nuclear Information System (INIS)

Guo Yonghai; Su Rui; Liu Shufen; Lu Chuanhe

2004-01-01

Based on the field investigation which has been carried out in the Beishan preselected area for high level radioactive waste repository in Gansu province during the last few years and the previous hydrogeological investigation results, the different groundwater types are divided initially and the hydrogeological features of different water-bearing media are described in this paper. Meanwhile, the preliminary evaluation of the regional hydrogeological condition of the study area is carried out. (author)

Repository Safety Strategy: Strategy for Protecting Public Health and Safety after Closure of a Yucca Mountain Repository, Rev. 1

Energy Technology Data Exchange (ETDEWEB)

DOE

1998-01-01

The updated Strategy to Protect Public Health and Safety explains the roles that the natural and engineered systems are expected to play in achieving the objectives of a potential repository system at Yucca Mountain. These objectives are to contain the radionuclides within the waste packages for thousands of years, and to ensure that annual doses to a person living near the site will be acceptably low. This strategy maintains the key assumption of the Site Characterization Plan (DOE 1988) strategy that the potential repository level (horizon) will remain unsaturated. Thus, the strategy continues to rely on the natural attributes of the unsaturated zone for primary protection by providing a setting where waste packages assisted by other engineered barriers are expected to contain wastes for thousands of years. As in the Site Characterization Plan (DOE 1988) strategy, the natural system from the walls of the underground openings (drifts) to the human environment is expected to provide additional defense by reducing the concentrations of any radionuclides released from the waste packages. The updated Strategy to Protect Public Health and Safety is the framework for the integration of site information, repository design and assessment of postclosure performance to develop a safety case for the viability assessment and a subsequent license application. Current site information and a reference design are used to develop a quantitative assessment of performance to be compared with a performance measure. Four key attributes of an unsaturated repository system that are critical to meeting the objectives: (1) Limited water contacting the waste packages; (2) Long waste package lifetime; (3) Slow rate of release of radionuclides from the waste form; and (4) Concentration reduction during transport through engineered and natural barriers.

Ventilation planning for a prospective nuclear waste repository

International Nuclear Information System (INIS)

Wallace, K.G. Jr.

1987-01-01

In 1982, the US Congress passed the Nuclear Waste Policy Act to provide for the development of underground repositories for spent nuclear fuel. This development will be managed by the United States Department of Energy. In 1986, the President selected three areas for site characterization to determine their suitability for the development of an underground repository; those sites were: (1) A site in volcanic tuff located at Yucca Mountain in Nevada, (2) a site in bedded salt located in Deaf Smith County in Texas, and (3) a site in basalt located in Hanford, Washington. At present conceptual repository designs are being developed for each site. A key element of a repository design is the underground ventilation system required to support construction, nuclear waste emplacement, and potential waste retrieval. This paper describes the preliminary ventilation systems designed for the repository in tuff. The concept provides separate ventilation systems for the construction and waste emplacement activities. The paper further describes the means by which acceptable environmental conditions will be re-established to allow re-entry into previously closed rooms for the purpose of inspection, maintenance or retrieval

Safety analysis of the transportation of radioactive waste to the Konrad final repository

International Nuclear Information System (INIS)

Sentuc, F.N.; Bruecher, W.

2010-01-01

A transport risk assessment study has been conducted for transport of radioactive waste with negligible heat-generation to the German final repository Konrad. This study is a revision of the former Konrad Transport Study performed by GRS in 1991 implementing updated waste data among other improved methods and assumptions for the purpose of a more realistic approach to risk assessment. The first part of the transport risk assessment study concerns the radiological consequences from normal (accident-free) transportation of radioactive material, i.e. the radiation exposure of transport personnel and the public. Based on the assessed detailed information on transport arrangements and on the average number and radiological characteristics of waste packages the maximum annual effective doses for the representative persons were estimated. The risk associated with transport incidents and accidents has been quantified for the area within a radius of 25 km around the repository site. The probabilistic method adopted in this study considers parameters as the frequency and severity of railway or road accidents, characteristics of radioactive waste and transport packagings and the frequency of atmospheric dispersion conditions. From a large set of parameter combinations the spectrum of potential radiological consequences and of the associated probability of occurrence was assessed. (orig.)

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)

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)

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.

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

Monitoring system specifications: retrieval of surf from a salt repository

International Nuclear Information System (INIS)

1980-01-01

The task of developing specifications for a reference monitoring system determined by repository environmental conditions, retrieval operations, and federal regulatory criteria is discussed. The monitoring system specified in this report is capable of measuring (1) package position and orientation, (2) vault deformation, (3) brine accumulation, (4) spent fuel dissolution, (5) temperature, (6) nuclear radiation, and (7) package condition with sufficient accuracy to provide data input to a general risk assessment model. In order to define a monitoring system which can provide probabilistic data on radiological risk to operating personnel and the general public for a salt mine repository, the following information is required: (1) a complete design of the salt SURF repository including inventory, density and waste package design details; (2) probalistic failure rate data on containment integrity of the SURF waste package; (3) probabilistic failure rate data on the monitoring system components

The analysis of repository-heat-driven hydrothermal flow at Yucca Mountain

International Nuclear Information System (INIS)

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

1993-01-01

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 the waste package (WP), accelerate its failure rate, and eventually transport radionuclides to the water table. In a concept called the ''extended-dry repository,'' decay heat arising from radioactive waste extends the time before liquid water can contact a WP. Recent modeling and theoretical advances in nonisothermal, multiphase fracture-matrix flow have demonstrated (1) the critical importance of capillary pressure disequilibrium between fracture and matrix flow, and (2) that radioactive decay heat plays a dominant role in the ability of the engineered and natural barriers to contain and isolate radionuclides. Our analyses indicate that the thermo-hydrological performance of both the unsaturated zone (UZ) and saturated zone (SZ) will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years. For thermal loads resulting in extended-dry repository conditions, UZ performance is primarily sensitive to the thermal properties and thermal loading conditions and much less sensitive to the highly spatially and temporally variable ambient hydrologic properties and conditions. The magnitude of repository-heat-driven buoyancy flow in the SZ is far more dependent on the total mass of emplaced spent nuclear fuel (SNF) than on the details of SNF emplacement, such as the Areal Power Density [(APD) expressed in kill/acre] or SNF age

Methods for definition of reference conditions for a repository site taking long-term environmental change into account

Energy Technology Data Exchange (ETDEWEB)

Ikonen, A.T.K. [Environmental Research and Assessment EnviroCase, Ltd. (Finland)

2014-07-01

In a few countries, programmes for disposal of spent nuclear fuel have proceeded into a site-specific phase, and the number of low- and intermediate-level nuclear waste repositories requiring updated state-of-the-art long-term safety assessments is considerable. In this contribution, the approach employed in the Finnish spent fuel disposal programme is analysed and used as an example for a more general methodology for defining reference surface conditions for a site, e.g. to guide selection of representative input data to safety assessments, using spatio-temporal analogues so that long-term environmental changes are taken into account. The contribution incorporates also elements from discussions in the IAEA EMRAS II and MODARIA working groups on addressing the environmental change in the assessments. The legacy of the earlier BIOMASS project is also recognised. Broadly, the methods to be presented include identification of similarity factors (e.g. geological, biological and climate regimes) upon which a reference area can be delineated. Within the reference area, characteristic lines of development and biotopes are identified and described, and these are then used to guide further research and application of literature data to iteratively accumulate adequate understanding of the site conditions and relevant processes at the present and in the future (by projecting further the past and present development lines and biotopes). In this iterative approach, also the intensity of research efforts can be adjusted with the stage of the repository programme, as will be discussed in the complete contribution. Document available in abstract form only. (authors)

Relationship of engineering geology to conceptual repository design in the Gibson Dome area, Utah

International Nuclear Information System (INIS)

Helgerson, R.; Henderson, N.

1984-01-01

The Paradox Basin in Southeastern Utah is being investigated as a potential site for development of a high-level nuclear waste repository. Geologic considerations are key areas of concern and influence repository design from a number of aspects: depth to the host rock, thickness of the host rock, and hydrologic conditions surrounding the proposed repository are of primary concern. Surface and subsurface investigations have provided data on these key geologic factors for input to the repository design. A repository design concept, based on the surface and subsurface geologic investigations conducted at Gibson Dome, was synthesized to provide needed information on technical feasibility and cost for repository siting decision purposes. Significant features of the surface and subsurface repository facilities are presented. 5 references, 4 figures

Earth and Environmental Sciences 1999 Annual Report Meeting National Needs

International Nuclear Information System (INIS)

Yonker, L.; Dannevik, B.

2000-01-01

Lawrence Livermore National Laboratory's Earth and Environmental Sciences 1999 Annual Report covers the following topics: (1) Nuclear Materials--Modeling Thermohydrologic Processes at the Proposed Yucca Mountain Nuclear-Waste Repository; Dose Assessments and Resettlement Support on Rongelap Atoll in the Marshall Islands. (2) Climate, Carbon, and Energy--Incorporating Surprise into Models of Global Climate Change: A Simple Climate Demonstrator Model; (3) Environmental Risk Reduction--The NASA Global Modeling Initiative: Analyzing the Atmospheric Impacts of Supersonic Aircraft; (4) National Security--Atmospheric Release Assessment Programs; and (5) Cross-Cutting Technologies/Capabilities--Advances in Technology at the Center for Accelerator Mass Spectrometry; Experimental Geophysics: Investigating Material Properties at Extreme Conditions

Understanding large scale groundwater flow to aid in repository siting

International Nuclear Information System (INIS)

Davison, C.C.; Brown, A.; Gascoyne, M.; Stevenson, D.R.; Ophori, D.U.

1996-01-01

Atomic Energy of Canada Limited (AECL) with support from Ontario Hydro has developed a concept for the safe disposal of Canada's nuclear fuel waste in a deep (500 to 1000 m) mined repository in plutonic rocks of the Canadian Shield. The disposal concept involves the use of multiple engineered and natural barriers to ensure long-term safety. The geosphere, comprised of the enclosing rock mass and the groundwater which occurs in cracks and pores in the rock, is expected to serve as an important natural barrier to the release and migration of wastes from the engineered repository. Although knowledge of the physical and chemical characteristics of the groundwater in the rock at potential repository sites is needed to help design the engineered barriers of the repository it can also be used to aid in repository siting, to take greater advantage of natural conditions in the geosphere to enhance its role as a barrier in the overall disposal system

Definition of the waste package environment for a repository located in salt

International Nuclear Information System (INIS)

Clark, D.E.; Bradley, D.J.

1983-01-01

The expected environmental conditions for emplaced waste packages in a salt repository are simulated in the materials testing program to evaluate performance. Synthetic brines, based on the analyses of actual brines (both intrusion and inclusion), are used for corrosion and leach testing. Elevated temperatures (to 150 0 C) and radiation fields of up to 10 3 rad/h are employed as conservative conditions to bracket expected performance and provide data for worst case scenarios. Obtaining a precise definition of the waste package environment in a salt repository and its change with time is closely tied to detailed site characterization of the candidate salt repository horizon. It is expected that field testing can augment some of the materials testing currently under way and can provide increased confidence in the predicted site-specific near-field conditions. 17 references, 5 figures, 1 table

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)

SKB Annual Report 1995. Including summaries of Technical Reports issued during 1995

International Nuclear Information System (INIS)

1996-05-01

The annual report covers planning, construction and operation of facilities and systems as well as research, development, demonstration work and information activities. The aim of the program is to start the permanent disposal of spent nuclear fuel around year 2008. Work is undertaken for the development of encapsulation technology on an industrial scale and for design of an encapsulation plant. The siting process for the final repository for spent fuel has started with feasibility studies in a few Swedish municipalities in order to evaluate the potential technical conditions and requirements and the influence on the region. 36 refs, figs

SKB Annual Report 1995. Including summaries of Technical Reports issued during 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-05-01

The annual report covers planning, construction and operation of facilities and systems as well as research, development, demonstration work and information activities. The aim of the program is to start the permanent disposal of spent nuclear fuel around year 2008. Work is undertaken for the development of encapsulation technology on an industrial scale and for design of an encapsulation plant. The siting process for the final repository for spent fuel has started with feasibility studies in a few Swedish municipalities in order to evaluate the potential technical conditions and requirements and the influence on the region. 36 refs, figs.

2016 Annual Technology Baseline (ATB)

Energy Technology Data Exchange (ETDEWEB)

Cole, Wesley; Kurup, Parthiv; Hand, Maureen; Feldman, David; Sigrin, Benjamin; Lantz, Eric; Stehly, Tyler; Augustine, Chad; Turchi, Craig; O' Connor, Patrick; Waldoch, Connor

2016-09-01

Consistent cost and performance data for various electricity generation technologies can be difficult to find and may change frequently for certain technologies. With the Annual Technology Baseline (ATB), National Renewable Energy Laboratory provides an organized and centralized dataset that was reviewed by internal and external experts. It uses the best information from the Department of Energy laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information. The ATB includes both a presentation with notes (PDF) and an associated Excel Workbook. The ATB includes the following electricity generation technologies: land-based wind; offshore wind; utility-scale solar PV; concentrating solar power; geothermal power; hydropower plants (upgrades to existing facilities, powering non-powered dams, and new stream-reach development); conventional coal; coal with carbon capture and sequestration; integrated gasification combined cycle coal; natural gas combustion turbines; natural gas combined cycle; conventional biopower. Nuclear laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information.

Uncertainty: a discriminator for above and below boiling repository design decisions

International Nuclear Information System (INIS)

Wilder, D G; Lin, W; Buscheck, T A; Wolery, T J; Francis, N D

2000-01-01

The US nuclear waste disposal program is evaluating the Yucca Mountain (YM) site for possible disposal of nuclear waste. Radioactive decay of the waste, particularly spent fuel, generates sufficient heat to significantly raise repository temperatures. Environmental conditions in the repository system evolve in response to this heat. The amount of temperature increase, and thus environmental changes, depends on repository design and operations. Because the evolving environment cannot be directly measured until after waste is emplaced, licensing decisions must be based upon model and analytical projections of the environmental conditions. These analyses have inherent uncertainties. There is concern that elevated temperatures increase uncertainty, because most chemical reaction rates increase with temperature and boiling introduces additional complexity of vapor phase reactions and transport. This concern was expressed by the NWTRB, particularly for above boiling temperatures. They state that ''the cooler the repository, the lower the uncertainty about heat-driven water migration and the better the performance of waste package materials. Above this temperature, technical uncertainties tend to be significantly higher than those associated with below-boiling conditions.'' (Cohon 1999). However, not all uncertainties are reduced by lower temperatures, indeed some may even be increased. This paper addresses impacts of temperatures on uncertainties

SKB annual report 1987

International Nuclear Information System (INIS)

1988-05-01

The annual report on the activities of the Swedish Nuclear Fuel and Waste Management contains in part I an overview of SKB activities in different fields. Part II gives a description of the research and development work on nuclear waste disposal performed during 1987. Lectures and publications during 1987 as well as reports issued in the SKB technical report series are listed in part III. Part IV contains the summaries of all technical reports issued during 1987. At Forsmark the first construction phase for the final repository for radioactive waste - SFR - is now completed. The repository is situated in crystalline rock under the Baltic Sea. The first construction phase includes rock caverns for 60 000 m 3 of waste. A second phase for additional 30 000 m 3 is planned to be built and commissioned around the year 2000. (orig./DG)

Development of thermal analysis method for the near field of HLW repository using ABAQUS

Energy Technology Data Exchange (ETDEWEB)

Kuh, Jung Eui; Kang, Chul Hyung; Park, Jeong Hwa [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-10-01

An appropriate tool is needed to evaluate the thermo-mechanical stability of high level radioactive waste (HLW) repository. In this report a thermal analysis methodology for the near field of HLW repository is developed to use ABAQUS which is one of the multi purpose FEM code and has been used for many engineering area. The main contents of this methodology development are the structural and material modelling to simulate a repository, setup of side conditions, e.g., boundary and load conditions, and initial conditions, and the procedure to selection proper material parameters. In addition to these, the interface programs for effective production of input data and effective change of model size for sensitivity analysis for disposal concept development are developed. The results of this work will be apply to evaluate the thermal stability and to use as main input data for mechanical analysis of HLW repository. (author). 20 refs., 15 figs., 5 tabs.

The deep geologic repository technology programme: toward a geoscience basis for understanding repository safety

International Nuclear Information System (INIS)

Jensen, M.R.

2007-01-01

Within the Deep Geologic Repository Technology Programme (DGRTP) several Geoscience activities are focused on advancing the understanding of groundwater flow system evolution and geochemical stability in a Canadian Shield setting as affected by long-term climate change. A key aspect is developing confidence in predictions of groundwater flow patterns and residence times as they relate to the safety of a deep geologic repository for used nuclear fuel waste. This is being achieved through a coordinated multi-disciplinary approach intent on: i) demonstrating coincidence between independent geo-scientific data; ii) improving the traceability of geo-scientific data and its interpretation within a conceptual descriptive model(s); iii) improving upon methods to assess and demonstrate robustness in flow domain prediction(s) given inherent flow domain uncertainties (i.e. spatial chemical/physical property distributions, boundary conditions) in time and space; and iv) improving awareness amongst geo-scientists as to the utility of various geo-scientific data in supporting a safety case for a deep geologic repository. This multi-disciplinary DGRTP approach is yielding an improved understanding of groundwater flow system evolution and stability in Canadian Shield settings that is further contributing to the geo-scientific basis for understanding and communicating aspects of DGR safety. (author)

An approach to improve Romanian geological repository planning

International Nuclear Information System (INIS)

Andrei, Veronica; Prisecaru, Ilie

2016-01-01

International standards recommend typical phases to be included within any national program for the development of a geological repository dedicated to disposal of the high level radioactive wastes generated in countries using nuclear power. However, these are not universally applicable and the content of each of these phases may need to be adapted for each national situation and regulatory and institutional framework. Several national geological repository programs have faced failures in schedules and have revised their programs to consider an adapted phased management approach. The authors have observed that in the case of those countries in the early phases of a geological repository program where boundary conditions have not been fully defined, international recommendations for handling delays/failures in the national program might not immediately help. This paper considers a case study of the influences of the national context risks on the current planning schedule of the Romanian national geological repository. It proposes an optimum solution for an integrated response to any significant adverse impact arising from these risks, enabling sustainable program planning

The industrial organization of the repository. Pitfall or logical?

International Nuclear Information System (INIS)

Frostenson, Magnus

2010-11-01

From a systems perspective the organization of the Swedish final repository project for nuclear waste is studied. Different aspects of organization are identified in the report, covering dimensions of geographical, operative, structural, responsibility and contextual organization. Following SKB's site selection for the applications for the final repository for spent nuclear system and the closing of the surplus value agreement, issues concerning operative, structural and contextual organization tend to become particularly pressing, which is reflected in three research questions: - How will the final repository project be organized operatively and structurally over time? - Why is the final repository project organized in this way by SKB? - What kind of contextual organization takes place in the final repository project and what are the consequences of these activities? How the different industrial units of the final repository project should be run and within which structure, for example concerning ownership and integration of units, is established in the report. SKB's reasons for choosing this kind of organization are also highlighted. Apart from legal and safety-related demands that must be met together with the demands of the owners, SKB's strategic preference for insourcing conditions organizational choices. The traditional task centred operative and structural organization of SKB is also reflected in the organizational choices for the present and future units of the final depository system. Contextual organization implies deepened actor relationships between SKB's owners and SKB on the one side and the municipalities Oesthammar and Oskarshamn on the other. Through active organizing, the final repository arena 'narrows down' and the final repository issue turns into an in many respects local issue. There is a clear tendency that the roles of SKB are multiplied in order to handle the demands that central stakeholders - in particular the municipalities - place on

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)

An initial study of the behaviour under repository conditions of inactive components of nuclear wastes

International Nuclear Information System (INIS)

Biddle, P.; Rees, J.H.

1988-02-01

This review extends the appreciation of repository behaviour to include the inactive components of wastes and their degradation products. These materials include a wide range of metals and organics, sludges and decommissioning wastes. The effect of degradation products on the solubility of long-lived radionuclides and any active daughters and their sorption on surfaces of the repository are assessed. Research requirements are identified that may help to improve significantly the assessment of the effects of inactive materials. Data required to improve the quality of inventory data on nuclear wastes are listed. (author)

Deep geological repository: Starting communication at potentially suitable sites

International Nuclear Information System (INIS)

Sumberova, Vera

2001-01-01

The siting of a deep geological repository in the Czech Republic is and will be a complicated process, since it is the first siting process of a nuclear facility designed from the start to be located at non-nuclear sites and to be organised under democratic conditions. This presentation describes the concept of radioactive waste and spent nuclear management in the Czech Republic, Communication activities of Radioactive Waste Repository Authority (RAWRA) with local representatives and lessons learned

Establishment of IAEA knowledge of integrity of the geological repository boundaries and disposed spent fuel assemblies in the context of the Finnish geological repository. Experts' Group meeting Report on Task JNT/C 1204 of the Member States' Support Programme to IAEA Safeguards

International Nuclear Information System (INIS)

Okko, O.

2004-05-01

The Geological Repository Safeguards Experts Group (Member State Support Programme tasks JNT/C1204 and C1226), agreed that annual meetings should be held to address interface issues between IAEA safeguards and radioactive waste management and to explore the use of safety and operational information to make International Atomic Energy Agency (IAEA) safeguards more effective and efficient for geological repository facilities. It has also been recognised that the safeguards measures for geological repositories are to be developed site-specifically. To address these issues to the planned Olkiluoto repository in Finland a meeting of experts in safety, geological repository operations,and safeguards from 6 States, European Commission, and IAEA was held in Olkiluoto and Rauma, Finland, during September 29 - October 4, 2003. The pre-operational phase of the Olkiluoto repository should be efficiently used by the parties involved in safeguards. The applicability and reliability of the potential new techniques and the efficient practices must be developed and proven before their implementation as safeguards measures to be applied at the subsequent stages of the repository development. The visit to the location of the proposed Olkiluoto repository and neighbouring areas and subsequent presentations enabled the working groups to discuss the various issues with reference to actual site conditions. The working groups were thus able to identify potential measurement and monitoring techniques and research and development requirements for consideration by the Finnish authorities, in addition to making recommendations to the IAEA on planned activities for carrying out before and during the early investigation phase of the proposed Olkiluoto repository. It was understood that all parties shall take good care of the implementation of the planned activities to ensure that proven means, approaches and the required verified information is at hand at the time the projected facility will

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…

Preliminary postclosure risk assessment: Yucca Mountain, Nevada, candidate repository site

International Nuclear Information System (INIS)

Eslinger, P.W.; Elwood, D.M.; Freshley, M.D.; Reimus, P.W.; Tanner, J.E.; Doctor, P.G.; Engel, D.W.; Liebetrau, A.M.; Strenge, D.L.; Van Luik, A.E.

1989-10-01

A study was conducted by the Pacific Northwest Laboratory for the US Department of Energy, Office of Civilian Radioactive Waste Management, to estimate the postclosure risk, in terms of population health effects, of a proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The risk estimates cover a time span of 1 million years following repository closure. Representative disruptive and intrusive events were selected and evaluated in addition to expected conditions. The estimates were generated assuming spent fuel as the waste form and included all important nuclides from inventory, half-life and dose perspectives. The base case results yield an estimate of 36 health effects over the first million years of repository operation. The doses attributed to the repository corresponds to about 0.1 percent of the doses received from natural background radiation. 16 refs., 1 fig

The repository ecology an approach to understanding repository and service interactions

CERN Document Server

CERN. Geneva; Hagemann, Melissa

2007-01-01

An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning.

NAGRA annual report 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-07-01

This report issued by the Swiss National Co-operative for the Disposal of Radioactive Waste NAGRA reviews the co-operative’s activities in the year 2012. In January 2012, the Swiss Federal Office of Energy (SFOE) announced the 20 proposals made by NAGRA for siting areas for nuclear waste repository surface facilities. The discussions within the framework of regional participation focused on the location and layout of the surface facility within the defined planning perimeter. Progress in NAGRA’s work on the safety-based comparison and further narrowing-down of the geological siting regions for the repositories is reported on. NAGRA’s mandate includes its responsibility for preparing the technical and scientific basis for the safe, long-term management of nuclear waste. Progress on the so-called ‘Sectorial Plan’ which addresses the fundamental question of how to safely dispose of all types of radioactive waste is reported on, as is the process of defining locations in Switzerland for one or more deep repositories for nuclear wastes. Public participation in the process is reported on and geochemical considerations involved in designing the repositories are looked at. The work done in the rock laboratories is summarised and international co-operation is noted. The NAGRA ‘Time Ride’ exhibition is also briefly looked at. The report is completed with listings of those involved in NAGRA’s Board of Directors, commissions and auditors along with the annual financial statement for 2012.

NAGRA annual report 2012

International Nuclear Information System (INIS)

2013-01-01

This report issued by the Swiss National Co-operative for the Disposal of Radioactive Waste NAGRA reviews the co-operative’s activities in the year 2012. In January 2012, the Swiss Federal Office of Energy (SFOE) announced the 20 proposals made by NAGRA for siting areas for nuclear waste repository surface facilities. The discussions within the framework of regional participation focused on the location and layout of the surface facility within the defined planning perimeter. Progress in NAGRA’s work on the safety-based comparison and further narrowing-down of the geological siting regions for the repositories is reported on. NAGRA’s mandate includes its responsibility for preparing the technical and scientific basis for the safe, long-term management of nuclear waste. Progress on the so-called ‘Sectorial Plan’ which addresses the fundamental question of how to safely dispose of all types of radioactive waste is reported on, as is the process of defining locations in Switzerland for one or more deep repositories for nuclear wastes. Public participation in the process is reported on and geochemical considerations involved in designing the repositories are looked at. The work done in the rock laboratories is summarised and international co-operation is noted. The NAGRA ‘Time Ride’ exhibition is also briefly looked at. The report is completed with listings of those involved in NAGRA’s Board of Directors, commissions and auditors along with the annual financial statement for 2012

International perspective on repositories for low level waste

International Nuclear Information System (INIS)

Bergstroem, Ulla; Pers, Karin; Almen, Ylva

2011-12-01

represent a common type of locality for a repository, given that siting criteria are fulfilled. There is also a site that was selected without any association to existing nuclear sites or mines. This is the case for the French L'Aube repository. National repositories for disposal of all waste arising in that country are common, e.g. El Cabril in Spain and Low Level Repository close to Drigg in United Kingdom. The depth of the repositories varies from being on the surface to down to 650 metres below ground. The geological conditions of the different repositories are described as well as engineered barriers, geographical location and, if available, information on safety analysis. It can be noted that in the safety analysis of repositories located close to the coast (such as in Sweden, Finland and the United Kingdom), the effect of post-glacial land rise or coastal erosion is taken into special consideration. In general, the size of the repository reflects the size of the nuclear programmes in the respective country. The activity content of the facility, both the total and normalised figures against the volume capacities, are compared for groups of radionuclides

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

represent a common type of locality for a repository, given that siting criteria are fulfilled. There is also a site that was selected without any association to existing nuclear sites or mines. This is the case for the French L'Aube repository. National repositories for disposal of all waste arising in that country are common, e.g. El Cabril in Spain and Low Level Repository close to Drigg in United Kingdom. The depth of the repositories varies from being on the surface to down to 650 metres below ground. The geological conditions of the different repositories are described as well as engineered barriers, geographical location and, if available, information on safety analysis. It can be noted that in the safety analysis of repositories located close to the coast (such as in Sweden, Finland and the United Kingdom), the effect of post-glacial land rise or coastal erosion is taken into special consideration. In general, the size of the repository reflects the size of the nuclear programmes in the respective country. The activity content of the facility, both the total and normalised figures against the volume capacities, are compared for groups of radionuclides

NAGRA Annual report 2010

International Nuclear Information System (INIS)

2011-04-01

This annual report presents the highlights of the activities carried out by the Swiss National Co-operative for the Disposal of Radioactive Wastes NAGRA during the year 2010. These include reviews by various commissions of the NAGRA co-operative's proposals for possible sites for nuclear waste repositories. Also, the enhancements made concerning information facilities for the general public at the co-operative's rock laboratories are mentioned. The operation of initial satellite-based precision measurement systems for movements in the earth's crust is noted. Organisational aspects and international co-operation are discussed. This annual report also looks at NAGRA's organisational structures and its commercial accounts. Appendices provide details on waste inventories and volumes and publications made in 2010. A selection of relevant internet addresses is also provided

Staff Technical Position on consideration of fault displacement hazards in geologic repository design

International Nuclear Information System (INIS)

McConnell, K.I.; Lee, M.P.

1994-09-01

Nuclear Regulatory Commission regulations for the disposal of spent nuclear fuel and high-level radioactive waste in a geologic repository recognize that fault displacement is a potentially adverse condition. However, they do not prohibit designing the geologic repository against the effects of such a potentially adverse condition. This Staff Technical Position recognizes the acceptability of designing the geologic repository to take into account the attendant effects (e.g., displacement) of faults of regulatory concern and expresses the staff's views on what is needed from the US Department of Energy if it chooses to locate structures, systems, and components important to safety or important to waste isolation in areas that contain faults of regulatory concern

Double Diffusive Natural Convection in a Nuclear Waste Repository

International Nuclear Information System (INIS)

Y. Hao; J. Nitao; T.A. Buscheck; Y. Sun

2006-01-01

In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport

Siting guidelines and their role in repository site selection

International Nuclear Information System (INIS)

Hanlon, C.L.

1985-01-01

The first requirement of the Nuclear Waste Policy Act was for the Secretary of Energy to issue general guidelines for siting repositories. The guidelines were to specify detailed geologic considerations that would be the primary criteria for the selection of sites in various host rocks, as well as factors that would qualify or disqualify any site from development as a repository. These guidelines were clearly intended to provide not only the framework for the siting program but also the stimulus for establishing effective communication and consultation among the parties involved in the program. The Act further required that the guidelines be a factor in the development of all future decision documents of the Office of Civilian Radioactive Waste Management, including the environmental assessments that would accompany the nomination of sites for characterization, the site-characterization plans that are to be prepared before the sinking of exploratory shafts at any candidate site, and the environmental impact statement that is to support the recommendation of a site for development as a repository. More than two years after its passage, the intention of the Act for the guidelines has been realized. Concurred in by the Nuclear Regulatory Commission on June 22, 1984, and issued by the Department in November 1984, the guidelines include postclosure technical guidelines that apply to conditions governing the long-term performance of the repository system; preclosure technical guidelines that apply to conditions governing the siting, construction, operation, and closure of the repository; and system guidelines whose objective is to ensure that the regulatory requirements of the Environmental Protection Agency and the Nuclear Regulatory Commission are met

The repository ecology: an approach to understanding repository and service interactions

CERN Multimedia

CERN. Geneva

2007-01-01

An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning. View John Robertson's biography

Developing multinational radioactive waste repositories: Infrastructural framework and scenarios of cooperation

International Nuclear Information System (INIS)

2004-10-01

Currently the management of radioactive wastes centres on national strategies for collection, treatment, interim storage and disposal. This tendency to focus exclusively on national strategies reflects the fact that radioactive waste is a sensitive political issue, making cooperation among countries difficult. It is consistent with the accepted principle that a country that enjoys the benefit of nuclear energy, or the utilization of nuclear technology, should also take full responsibility for managing the generated radioactive waste. However, there are countries whose radioactive waste volumes do not easily justify a national repository, and/or countries that do not have the resources or favourable natural conditions for waste disposal to dedicate to a national repository project or would prefer to collaborate in shared initiatives because of their economic advantages. In such cases it may be appropriate for these countries to engage in a multinational collaborative effort to ensure that they have access to a common repository, in order that they can fulfil their responsibilities for their managing wastes safely. In response to requests from several Member States expressing an interest in multinational disposal options, the IAEA produced in 1998 a TECDOC outlining the important factors to be taken into account in the process of realizing such options. These factors include for example, technical (safety), institutional (legal, safeguards), economic (financial) socio-political (public acceptance) and ethical considerations. The present report reviews the work done in the previous study, taking into account developments since its publication as well as current activities in the field of multinational repositories. The report attempts to define the concepts involved in the creation of multinational repositories, to explore the likely scenarios, to examine the conditions for successful implementation, and to point out the benefits and challenges inherent to

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

Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

Energy Technology Data Exchange (ETDEWEB)

Baeckblom, Goeran [Conrox (Sweden); Almen, Karl-Erik [KEA Geokonsult AB (Sweden)

2004-03-01

Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for

Local-scale modelling of density-driven flow for the phases of repository operation and post-closure at Beberg

International Nuclear Information System (INIS)

Jaquet, O.; Siegel, P.

2004-09-01

A hydrogeological model was developed for Beberg with the aim of evaluating the impact of a repository (for the operational and post-closure phases) while accounting for the effects of density-driven flow. Two embedded scales were taken into account for this modelling study: a local scale at which the granitic medium was considered as a continuum and a repository scale, where the medium is fractured and therefore was regarded to be discrete. The following step-wise approach was established to model density-driven flow at both repository and local scale: (a) modelling fracture networks at the repository scale, (b) upscaling the hydraulic properties to a continuum at local scale and (c) modelling density-driven flow to evaluate repository impact at local scale. The results demonstrate the strong impact of the repository on the flow field during the phase of operation. The distribution of the salt concentration is affected by a large upcoming effect with increased relative concentration and by the presence of fracture zones carrying freshwater from the surface. The concentrations obtained for the reference case, expressed in terms of percentage with respect to the maximum (prescribed) value in the model, are as follows: ca 30% for the phase of desaturation, and ca 20% for the resaturation phase. For the reference case, the impact of repository operations appears no longer visible after a resaturation period of about 20 years after repository closure; under resaturation conditions, evidence of the operational phase has already disappeared in terms of the observed hydraulic and concentration fields. Sensitivity calculations have proven the importance of explicitly discretising repository tunnels when assessing resaturation time and maximum concentration values. Furthermore, the definition of a fixed potential as boundary condition along the model's top surface is likely to provide underestimated values for the maximum concentration and overestimated flow rates in the

Identification of candidate sites for a near surface repository for radioactive waste

International Nuclear Information System (INIS)

Motiejunas, S.

2004-01-01

This Report comprises results of the area survey stage, which involves regional screening to define the regions of interest and identification of potential sites within suitable regions. The main goal was to define a few sites potentially suitable for constructing of the near surface repository. It was concluded that a vicinity of Ignalina NPP is among the best suitable regions for the near surface repository. At the present investigation level a ridge in Galilauke village has the most favorable conditions. However, Apvardai site is potentially suitable for the repository too

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

. Mathematical models play an even larger role in evaluating repository safety in the much longer postclosure period. During this period, repository performance is evaluated considering gradual degradation of engineered barriers, together with possible slow changes in the natural system (e.g., climate) and under conditions of potential discrete and sudden disruptive events (e.g., volcanic eruption, seismic ground motion, and direct fault movement). The general aim of postclosure performance assessment models is to simulate the future behavior of the repository in a manner that is sufficiently simplified to be tractable, yet sufficiently realistic to give reasonable (or bounded) estimates of risk to future generations. The simplifications are based on information gained by using process level models, natural analog studies, and laboratory and fieldwork. Because of large uncertainties inherent in characterizing a large and complex system for such long periods, probabilistic simulations are generally preferred. In this paper, we briefly describe the preclosure and postclosure safety evaluation models developed jointly by the Center for Nuclear Waste Regulatory Analyses and the U.S. Nuclear Regulatory Commission. We give examples illustrating how we intend to use these models within the regulatory framework to evaluate the required.

Evaluation of repository safety

International Nuclear Information System (INIS)

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

2002-01-01

. Mathematical models play an even larger role in evaluating repository safety in the much longer postclosure period. During this period, repository performance is evaluated considering gradual degradation of engineered barriers, together with possible slow changes in the natural system (e.g., climate) and under conditions of potential discrete and sudden disruptive events (e.g., volcanic eruption, seismic ground motion, and direct fault movement). The general aim of postclosure performance assessment models is to simulate the future behavior of the repository in a manner that is sufficiently simplified to be tractable, yet sufficiently realistic to give reasonable (or bounded) estimates of risk to future generations. The simplifications are based on information gained by using process level models, natural analog studies, and laboratory and fieldwork. Because of large uncertainties inherent in characterizing a large and complex system for such long periods, probabilistic simulations are generally preferred. In this paper, we briefly describe the preclosure and postclosure safety evaluation models developed jointly by the Center for Nuclear Waste Regulatory Analyses and the U.S. Nuclear Regulatory Commission. We give examples illustrating how we intend to use these models within the regulatory framework to evaluate the required

Radiation effects on materials in the near-field of a nuclear waste repository. 1997 annual progress report

International Nuclear Information System (INIS)

Ewing, R.C.; Wang, L.M.

1997-01-01

'Sheet silicates (e.g. micas and clays) are important constituents of a wide variety of geological formations such as granite, basalt, and sandstone. Sheet silicates, particularly clays such as bentonite are common materials in near-field engineered barriers in high-level nuclear waste (HLW) repositories. This is because migration of radionuclides from an underground HLW repository to the geosphere may be significantly reduced by sorption of radionuclides (e.g., Pu, U and Np) onto sheet silicates (e.g., clays and micas) that line the fractures and pores of the rocks along groundwater flowpaths. In addition to surface sorption, it has been suggested that some sheet silicates may also be able to incorporate many radionuclides, such as Cs and Sr, in the inter-layer sites of the sheet structure. However, the ability of the sheet silicates to incorporate radionuclides and retard release and migration of radionuclides may be significantly affected by the near-field radiation due to the decay of fission products and actinides. for example, the unique properties of the sheet structures will be lost completely if the structure becomes amorphous due to irradiation effects. Thus, the study of irradiation effects on sheet-structures, such as structural damage and modification of chemical properties, are critical to the performance assessment of long-term repository behavior.'

Site selection of a deep repository of HLRW in relation to geological conditions of Slovak Republic

International Nuclear Information System (INIS)

Kovacik, M.; Kovacikova, M.; Madaras, J.; Vandlikova, M.

1996-01-01

All countries which use nuclear energy to generate electricity face the problem of high level radioactive waste (HLRW) and spent fuel. Until 1987, this problem was addressed in Czechoslovakia by transferring the material to the former USSR. After the political changes in Central and Eastern Europe in 1989 and the division of Czechoslovakia into two states in 1993, Slovakia independently faced the complex problem of creating its own deep repository. Although Slovakia has begun to solve the problem of HLRW and spent fuel only recently, it can take advantage of the theoretical and practical knowledge of other countries in this field. The geological aspects of the setting of the deep repository of HLRW have been studied within the project R epositories of radioactive and hazardous wastes in geological environment. The assessment of the Slovak Republic for creating a repository of HLRW was based on the application of internationally determined and applied criteria

National Aeronautics and Space Administration Biological Specimen Repository

Science.gov (United States)

McMonigal, Kathleen A.; Pietrzyk, Robert a.; Johnson, Mary Anne

2008-01-01

The National Aeronautics and Space Administration Biological Specimen Repository (Repository) is a storage bank that is used to maintain biological specimens over extended periods of time and under well-controlled conditions. Samples from the International Space Station (ISS), including blood and urine, will be collected, processed and archived during the preflight, inflight and postflight phases of ISS missions. This investigation has been developed to archive biosamples for use as a resource for future space flight related research. The International Space Station (ISS) provides a platform to investigate the effects of microgravity on human physiology prior to lunar and exploration class missions. The storage of crewmember samples from many different ISS flights in a single repository will be a valuable resource with which researchers can study space flight related changes and investigate physiological markers. The development of the National Aeronautics and Space Administration Biological Specimen Repository will allow for the collection, processing, storage, maintenance, and ethical distribution of biosamples to meet goals of scientific and programmatic relevance to the space program. Archiving of the biosamples will provide future research opportunities including investigating patterns of physiological changes, analysis of components unknown at this time or analyses performed by new methodologies.

The design of the Bulgaria rad waste repository

International Nuclear Information System (INIS)

Stefonova, I.; Petrov, I.; Navarro, M.; Sanchez, M.; Medinilla, G.

2012-01-01

In October 2011 a consortium composed by Westinghouse Engineering Spain SAU, ENRESA and DBE Technology GmbH was awarded a contract for the design of the Bulgaria rad waste repository. The facility, inspired in the spanish centre of El Cabril owned by ENRESA, will consist of a 66 reinforced concrete cells surface repository capable of receiving 18600 already conditioned waste containers of 20 t each, during 60 years, and the related auxiliary facilities and buildings. The project, representing a challenge because of the schedule and required level of detail, goes on fulfilling main milestones and getting customer satisfaction. (Author)

Study of the influence of hydrogeological conditions in the upper aquifer on radionuclide migration from a geological repository using a 2D groundwater flow model

Energy Technology Data Exchange (ETDEWEB)

Shestopalov, Vyacheslav; Bohuslavskyy, Alexander; Shybetskyi, Iurii [National Academy of Science of Ukaraine, Kyiv (Ukraine). Radioenvironmental Centre

2015-07-01

Results are presented of a case groundwater flow-transport modeling to predict the radionuclide migration from a deep geological repository (DGR) of radioactive waste. The influence of hydrogeological conditions in the upper aquifers of a storey water exchange system on the rate of contaminant migration from the DGR to its natural far-field groundwater discharges (a shallow well and a river) as a general DGR safety condition is considered.

The preliminary design and feasibility study of the spent fuel and high level waste repository in the Czech Republic

International Nuclear Information System (INIS)

Valvoda, Z.; Holub, J.; Kucerka, M.

1996-01-01

In the year 1993, began the Program of Development of the Spent Fuel and High Level Waste Repository in the Conditions of the Czech Republic. During the first phase, the basic concept and structure of the Program has been developed, and the basic design criteria and requirements were prepared. In the conditions of the Czech Republic, only an underground repository in deep geological formation is acceptable. Expected depth is between 500 to 1000 meters and as host rock will be granites. A preliminary variant design study was realized in 1994, that analyzed the radioactive waste and spent fuel flow from NPPs to the repository, various possibilities of transportation in accordance to the various concepts of spent fuel conditioning and transportation to the underground structures. Conditioning and encapsulation of spent fuel and/or radioactive waste is proposed on the repository site. Underground disposal structures are proposed at one underground floor. The repository will have reserve capacity for radioactive waste from NPPs decommissioning and for waste non acceptable to other repositories. Vertical disposal of unshielded canisters in boreholes and/or horizontal disposal of shielded canisters is studied. As the base term of the start up of the repository operation, the year 2035 has been established. From this date, a preliminary time schedule of the Project has been developed. A method of calculating leveled and discounted costs within the repository lifetime, for each of selected 5 variants, was used for economic calculations. Preliminary expected parametric costs of the repository are about 0,1 Kc ($0.004) per MWh, produced in the Czech NPPs. In 1995, the design and feasibility study has gone in more details to the technical concept of repository construction and proposed technologies, as well as to the operational phase of the repository. Paper will describe results of the 1995 design work and will present the program of the repository development in next period

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

Statistical methods for mechanistic model validation: Salt Repository Project

International Nuclear Information System (INIS)

Eggett, D.L.

1988-07-01

As part of the Department of Energy's Salt Repository Program, Pacific Northwest Laboratory (PNL) is studying the emplacement of nuclear waste containers in a salt repository. One objective of the SRP program is to develop an overall waste package component model which adequately describes such phenomena as container corrosion, waste form leaching, spent fuel degradation, etc., which are possible in the salt repository environment. The form of this model will be proposed, based on scientific principles and relevant salt repository conditions with supporting data. The model will be used to predict the future characteristics of the near field environment. This involves several different submodels such as the amount of time it takes a brine solution to contact a canister in the repository, how long it takes a canister to corrode and expose its contents to the brine, the leach rate of the contents of the canister, etc. These submodels are often tested in a laboratory and should be statistically validated (in this context, validate means to demonstrate that the model adequately describes the data) before they can be incorporated into the waste package component model. This report describes statistical methods for validating these models. 13 refs., 1 fig., 3 tabs

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...

Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

International Nuclear Information System (INIS)

Baeckblom, Goeran; Almen, Karl-Erik

2004-03-01

Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for monitoring are

Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

International Nuclear Information System (INIS)

Francis, A.J.; Gillow, J.B.; Giles, M.R.

1997-03-01

Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 micromol/g cellulose/day in anaerobic samples without nutrients, 0.05 micromol/g cellulose/day in the presence of nutrients, and 0.2 micromol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N 2 O in the headspace (200 micromol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO 2 production to 0.3 micromol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO 2 at a rate of 0.2 micromol/g cellulose/day in the absence of nutrients, and 1 micromol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber

Zircaloy cladding corrosion degradation in a Tuff repository: initial experimental plan

International Nuclear Information System (INIS)

Smith, H.D.

1984-07-01

The projected environmental history of a Tuff repository sited in an unsaturated hydrologic setting is evaluated to identify the potentially most severe corrosion conditions for Zircaloy spent fuel cladding. Three distinct corrosion periods are identified over the projected history. In two of those, liquid water may be present which is believed to produce the most severe corrosive environment for Zircaloy spent fuel cladding. In the time interval 100 to 1000 years after emplacement in the repository, the most severe condition is exposure to 170 0 C water at about 100 psi in an unbreached canister. This condition will be reproduced experimentally in an autoclave. For times after 1000 years, the most severe condition is exposure to 90 0 C water that is equilibrated with the tuff and invades breached canisters. This condition will be reproduced with a water bath system

Radionuclide transport from near-surface repository for radioactive waste - The unsaturated zone approach

Energy Technology Data Exchange (ETDEWEB)

Jakimaviciute-Maseliene, V. [Vilnius University (Lithuania); Mazeika, J. [Nature Research Centre (Lithuania); Motiejunas, S. [Radioactive Waste Management Agency (Lithuania)

2014-07-01

About 100 000 m{sup 3} of solid conditioned Low and Intermediate Level Waste (LILW), generated during operation and decommissioning of the Ignalina nuclear power plant (INPP), are to be disposed of in a near-surface repository (NSR) - a 'hill'-type repository with reinforced concrete vaults and with engineered and natural barriers. The northeastern Lithuania and the environment of the INPP in particular were recognized as the areas most suitable for a near-surface repository (Stabatiske Site). The engineered barriers of the repository consist of concrete cells surrounded by clay-based material of low permeability with about the same isolating capacity in all directions. The clay materials must be effectively compactable so that required hydraulic conductivity is reached. The Lithuanian Triassic clay turned out to be sufficiently rich in smectites and was proposed as main candidate for sealing of the repository. When the concrete vaults are filled, the repository cover will be constructed. The surface of the mound will be planted with grass. In this study a computer code FEFLOW 5.0 was applied for simulating the transport of the most mobile radionuclides ({sup 3}H, {sup 14}C, {sup 59}Ni and {sup 94}Nb) with moisture through an unsaturated vault of the near-surface repository in Stabatiske Site. The HYDRUS-1D analysis was used to assess the radionuclide transport in the repository and to estimate initial activity concentrations of radionuclides transported from the cemented waste matrix. Radionuclide release from the vault in the unsaturated conditions after closure of the repository and consequent contaminant plume transport has been assessed taking into account site-specific natural and engineering conditions and based on a normal evolution scenario. The highest peak radionuclide activity concentrations were estimated applying the FEFLOW code. The highest value of {sup 14}C activity concentration(about 1.3x10{sup 8} Bq/m{sup 3}) at the groundwater table

Investigations of natural groundwater hazards at the proposed Yucca Mountain high level nuclear waste repository. Part A: Geology at Yucca Mountain. Part B: Modeling of hydro-tectonic phenomena relevant to Yucca Mountain. Annual report - Nevada

International Nuclear Information System (INIS)

Szymanski, J.S.; Schluter, C.M.; Livingston, D.E.

1993-05-01

This document is an annual report describing investigations of natural groundwater hazards at the proposed Yucca Mountain, Nevada High-Level Nuclear Waste Repository.This document describes research studies of the origin of near surface calcite/silica deposits at Yucca Mountain. The origin of these deposits is controversial and the authors have extended and strengthened the basis of their arguments for epigenetic, metasomatic alteration of the tuffs at Yucca Mountain. This report includes stratigraphic, mineralogical, and geochronological information along with geochemical data to support the conclusions described by Livingston and Szymanski, and others. As part of their first annual report, they take this opportunity to clarify the technical basis of their concerns and summarize the critical geological field evidence and related information. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

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)

Salt Repository Project: Waste Package Program (WPP) modeling activiteis: FY 1984 annual report

International Nuclear Information System (INIS)

Kuhn, W.L.; Simonson, S.A.; Pulsipher, B.A.

1987-03-01

The Pacific Northwest Laboratory (PNL) is supporting the US Department of Energy's (DOE) Salt Repository Project (SRP) through its Waste Package Program (WPP). During FY 1984, the WPP continued its program of waste package component development and interactions testing and application of the resulting data base to develop predictive models describing waste package degradation and radionuclide release. Within the WPP, the Modeling Task (Task 04 during FY 1984) was conducted to interpret the tests in such a way that scientifically defensible models can be developed for use in qualification of the waste package

Radionuclide getters in the near-field chemistry of repositories. Annual report - February 1989

International Nuclear Information System (INIS)

Holland, T.R.; Lee, D.J.

1989-02-01

A programme of work has commenced to assess the radionuclide sorption efficiency of selected inorganic 'getters' incorporated into sulphate resisting Portland cement; as a means of enhancing the retention of radioactive species by the proposed repository backfill. For this initial study, a limited number of radioisotopes have been selected, with particular reference to those likely to be mobile in an alkaline environment, ie. Ra-266, Cs-134 and I-125. The getters chosen for this stage of the programme were Clinoptilolite, Molecular Sieve 5a, Tobermorite and Ferric Floc. (author)

NAGRA Annual report 2010

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-04-15

This annual report presents the highlights of the activities carried out by the Swiss National Co-operative for the Disposal of Radioactive Wastes NAGRA during the year 2010. These include reviews by various commissions of the NAGRA co-operative's proposals for possible sites for nuclear waste repositories. Also, the enhancements made concerning information facilities for the general public at the co-operative's rock laboratories are mentioned. The operation of initial satellite-based precision measurement systems for movements in the earth's crust is noted. Organisational aspects and international co-operation are discussed. This annual report also looks at NAGRA's organisational structures and its commercial accounts. Appendices provide details on waste inventories and volumes and publications made in 2010. A selection of relevant internet addresses is also provided

Low- and intermediate-level waste repository-induced effects

Energy Technology Data Exchange (ETDEWEB)

Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom); Savage, D. [Savage Earth Associates Ltd, Bournemouth, Dorset (United Kingdom); Senger, R. [Intera Inc., Ennetbaden (Switzerland)

2016-10-15

system has been designed to perform with sufficient safety margin for a range of siting conditions. The barriers include the host rock, its surrounding geological setting, the waste forms, drums and the cementitious backfill. They have a range of attributes that intrinsically favour safety and that avoid or minimise detrimental phenomena and uncertainties or mitigate their effects. Nevertheless, potentially detrimental repository-induced effects remain and in the present report, these are investigated and discussed considering a broad spectrum of parameters, reflecting, among other things, the range of potential siting conditions. The L/ILW emplacement caverns are designed, constructed, operated and finally backfilled in such a way that formation of excavation damaged zones is limited. Specifically this is achieved by restricting the size of the excavations and the depth of the repository, using a low-deformation, controlled construction and excavation method and by the fact that the excavations will be backfilled relatively soon after construction with grain supported mortar. At expected repository depths, the caverns will need to be supported to ensure stability and worker protection; this will prevent rock falls and further extension of the EDZ. Based on the modelling results, it can be concluded that the extent of the EDZ around the L/ILW emplacement caverns will not exceed a thickness of one cavern diameter and that the hydraulic conductance of the EDZ around the emplacement caverns, access tunnels and shafts will not exceed a value of 10{sup -7} m{sup 3}/s. Self sealing of the EDZ and low hydraulic gradients along the tunnels will result in negligible radionuclide transport by the EDZ pathway. It is shown that gas pressure build-up is controlled by the gas transport capacity of the pathways between the main repository and the access tunnel forming the so-called EGTS. Results obtained with the sensitivity cases for a repository depth of 500 m below ground level

Low- and intermediate-level waste repository-induced effects

International Nuclear Information System (INIS)

Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J.; Smith, P.; Savage, D.; Senger, R.

2016-10-01

system has been designed to perform with sufficient safety margin for a range of siting conditions. The barriers include the host rock, its surrounding geological setting, the waste forms, drums and the cementitious backfill. They have a range of attributes that intrinsically favour safety and that avoid or minimise detrimental phenomena and uncertainties or mitigate their effects. Nevertheless, potentially detrimental repository-induced effects remain and in the present report, these are investigated and discussed considering a broad spectrum of parameters, reflecting, among other things, the range of potential siting conditions. The L/ILW emplacement caverns are designed, constructed, operated and finally backfilled in such a way that formation of excavation damaged zones is limited. Specifically this is achieved by restricting the size of the excavations and the depth of the repository, using a low-deformation, controlled construction and excavation method and by the fact that the excavations will be backfilled relatively soon after construction with grain supported mortar. At expected repository depths, the caverns will need to be supported to ensure stability and worker protection; this will prevent rock falls and further extension of the EDZ. Based on the modelling results, it can be concluded that the extent of the EDZ around the L/ILW emplacement caverns will not exceed a thickness of one cavern diameter and that the hydraulic conductance of the EDZ around the emplacement caverns, access tunnels and shafts will not exceed a value of 10 -7 m 3 /s. Self sealing of the EDZ and low hydraulic gradients along the tunnels will result in negligible radionuclide transport by the EDZ pathway. It is shown that gas pressure build-up is controlled by the gas transport capacity of the pathways between the main repository and the access tunnel forming the so-called EGTS. Results obtained with the sensitivity cases for a repository depth of 500 m below ground level indicate that

Assessment of Savannah River borosilicate glass in the repository environment

International Nuclear Information System (INIS)

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

1982-04-01

Since 1973, borosilicate glass has been studied as a matrix for the immobilization of high-level radioactive waste generated at the Savannah River Plant (SRP). In 1977, efforts began to develop and test the large-scale equipment necessary to convert the alkaline waste slurries at SRP into a durable borosilicate glass. A process has now been developed for the proposed Defense Waste Processing Facility (DWPF) which will annually produce approximately 500 canisters of SRP waste glass which will be stored on an interim basis on the Savannah River site. Current national policy calls for the permanent disposal of high-level waste in deep geologic repositories. In the repository environment, SRP waste glass will eventually be exposed to such stresses as lithostatic or hydrostatic pressures, radiation fields, and self-heating due to radioactive decay. In addition, producing and handling each canister of glass will also expose the glass to thermal and mechanical stresses. An important objective of the extensive glass characterization and testing programs of the Savannah River Laboratory (SRL) has been to determine how these stresses affect the performance of SRP waste glass. The results of these programs indicate that: these stresses will not significantly affect the performance of borosilicate glass containing SRP waste; and SRP waste glass will effectively immobilize hazardous radionuclides in the repository environment

Staged Repository Development Programmes

International Nuclear Information System (INIS)

Isaacs, T

2003-01-01

probability of program success, including a redefinition of what success means. The key objective is to come to broad agreement on a program approach that will result in a suitable repository, performing better than required, with the flexibility to adapt to experience and be prepared to change or even reverse direction if conditions merit. The step-wise and transparent approach is intended to foster implementer and regulator behavior that earns the trust and confidence of the many diverse stakeholders and the public by proceeding in a manner that makes it clear that the program is striving to meet their needs and fully address their concerns

Industrial complementarities between interim storage and reversible geological repository - 59237

International Nuclear Information System (INIS)

Hoorelbeke, Jean-Michel

2012-01-01

The French Act voted in 2006 made the choice of deep geological disposal as the reference option for the long term management of high level (HLW) and intermediate level long-lived waste. The CIGEO repository project aims at avoiding or limiting burden to future generations, which could not be achieved by the extension in time of interim storage. The reversibility as provided by the Act will maintain a liberty of choice for waste management on a duration which is comparable to new storage facility. Interim storage is required to accommodate waste as long as the repository is not available. The commissioning of the repository in 2025 will not suppress needs for interim storage. The paper describes the complementarities between existing and future interim storage facilities and the repository project: repository operational issues and planning, HLW thermal decay, support for the reversibility, etc. It shows opportunities to prepare a global optimization of waste management including the utilization at best of storage capacities and the planning of waste emplacement in the repository in such a way to facilitate operational conditions and to limit cost. Preliminary simulations of storage-disposal scenarios are presented. Thanks to an optimal use of the waste management system, provision can be made for a progressive increase of waste emplacement flow during the first operation phase of the repository. It is then possible to stabilize the industrial activity level of the repository site. An optimal utilization of interim storage can also limit the diversity of waste packages emplaced simultaneously, which facilitates the operation of the repository. 60 years minimum interim storage duration is generally required with respect to HLW thermal output. Extending this interim storage period may reduce the underground footprint of the repository. Regarding reversibility, the capability to manage waste packages potentially retrieved from the repository should be analyzed. The

Thermal Conductivity of the Potential Repository Horizon Model Report

International Nuclear Information System (INIS)

Ramsey, J.

2002-01-01

The purpose of this report is to assess the spatial variability and uncertainty of thermal conductivity in the host horizon for the proposed 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). The Tptpul is the layer directly above the repository host layers, which consist of the Tptpmn, Tptpll, and the Tptpln. Current design plans indicate that the largest portion of the repository will be excavated in the Tptpll (Board et al. 2002 [157756]). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large scale (cm-m) 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 and perhaps repository system performance as well. To assess the spatial variability and uncertainty of thermal conductivity, a model is proposed that is functionally dependent on the volume fraction of lithophysae and the thermal conductivity of the matrix portion of the rock. In this model, void space characterized as lithophysae is assumed to be air-saturated under all conditions, while void space characterized as matrix may be either water- or air-saturated. Lithophysae are assumed to be air-saturated under all conditions since the units being studied are all located above the water table in the region of interest, and the relatively strong capillary forces of the matrix will, under most conditions, preferentially retain any moisture present in the rock

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.

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

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

A Climate Statistics Tool and Data Repository

Science.gov (United States)

Wang, J.; Kotamarthi, V. R.; Kuiper, J. A.; Orr, A.

2017-12-01

Researchers at Argonne National Laboratory and collaborating organizations have generated regional scale, dynamically downscaled climate model output using Weather Research and Forecasting (WRF) version 3.3.1 at a 12km horizontal spatial resolution over much of North America. The WRF model is driven by boundary conditions obtained from three independent global scale climate models and two different future greenhouse gas emission scenarios, named representative concentration pathways (RCPs). The repository of results has a temporal resolution of three hours for all the simulations, includes more than 50 variables, is stored in Network Common Data Form (NetCDF) files, and the data volume is nearly 600Tb. A condensed 800Gb set of NetCDF files were made for selected variables most useful for climate-related planning, including daily precipitation, relative humidity, solar radiation, maximum temperature, minimum temperature, and wind. The WRF model simulations are conducted for three 10-year time periods (1995-2004, 2045-2054, and 2085-2094), and two future scenarios RCP4.5 and RCP8.5). An open-source tool was coded using Python 2.7.8 and ESRI ArcGIS 10.3.1 programming libraries to parse the NetCDF files, compute summary statistics, and output results as GIS layers. Eight sets of summary statistics were generated as examples for the contiguous U.S. states and much of Alaska, including number of days over 90°F, number of days with a heat index over 90°F, heat waves, monthly and annual precipitation, drought, extreme precipitation, multi-model averages, and model bias. This paper will provide an overview of the project to generate the main and condensed data repositories, describe the Python tool and how to use it, present the GIS results of the computed examples, and discuss some of the ways they can be used for planning. The condensed climate data, Python tool, computed GIS results, and documentation of the work are shared on the Internet.

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)

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.

BMI and BMI SDS in childhood: annual increments and conditional change.

Science.gov (United States)

Brannsether, Bente; Eide, Geir Egil; Roelants, Mathieu; Bjerknes, Robert; Júlíusson, Pétur Benedikt

2017-02-01

Background Early detection of abnormal weight gain in childhood may be important for preventive purposes. It is still debated which annual changes in BMI should warrant attention. Aim To analyse 1-year increments of Body Mass Index (BMI) and standardised BMI (BMI SDS) in childhood and explore conditional change in BMI SDS as an alternative method to evaluate 1-year changes in BMI. Subjects and methods The distributions of 1-year increments of BMI (kg/m 2 ) and BMI SDS are summarised by percentiles. Differences according to sex, age, height, weight, initial BMI and weight status on the BMI and BMI SDS increments were assessed with multiple linear regression. Conditional change in BMI SDS was based on the correlation between annual BMI measurements converted to SDS. Results BMI increments depended significantly on sex, height, weight and initial BMI. Changes in BMI SDS depended significantly only on the initial BMI SDS. The distribution of conditional change in BMI SDS using a two-correlation model was close to normal (mean = 0.11, SD = 1.02, n = 1167), with 3.2% (2.3-4.4%) of the observations below -2 SD and 2.8% (2.0-4.0%) above +2 SD. Conclusion Conditional change in BMI SDS can be used to detect unexpected large changes in BMI SDS. Although this method requires the use of a computer, it may be clinically useful to detect aberrant weight development.

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

Climate Considerations in Long-Term Safety Assessments for Nuclear Waste Repositories

Energy Technology Data Exchange (ETDEWEB)

Naeslund, Jens-Ove; Brandefelt, Jenny; Claesson Liljedahl, Lillemor [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)], E-mail: jens-ove.naslund@skb.se

2013-05-15

For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

Environmental assessment: Reference repository location, Hanford site, Washington

Energy Technology Data Exchange (ETDEWEB)

none,

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites suitable for characterization.

Environmental assessment: Reference repository location, Hanford site, Washington

Energy Technology Data Exchange (ETDEWEB)

none,

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that is is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites available for characterization.

Environmental assessment: Reference repository location, Hanford site, Washington

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites suitable for characterization

Environmental assessment: Reference repository location, Hanford site, Washington

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that is is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites available for characterization

Siting regions for deep geological repositories. Why just here?

International Nuclear Information System (INIS)

Rieser, A.

2009-09-01

This report helps to the popularization of the Nagra works accomplished for the management and disposal of the radioactive wastes in Switzerland. The programme for management and disposal of the radioactive wastes are extensively determined by regulations. Protection of mankind and environment is the primary objective. The basic storage process is considered as having been solved. The question addressed in the report is where the facility has to be built; the site selection procedure includes five steps: 1) according to their type the wastes have to be allocated to two different repositories: for low- and intermediate-level wastes (L/ILW), and for high-level and alpha-toxic wastes (HLW); 2) the safety concept for both repositories and the requirements on the geology have to be determined; 3) large suitable geological-tectonic zones must be found where repositories could be built; 4) in these geological zones a suitable host rock has to be identified; 5) the most important spatial geological conditions of the host rock (minimum depth with respect to surface erosion, maximum depth in terms of engineering requirements, lateral extent) have to be identified. Based on these criteria, three suitable siting regions for a HLW repository were found in the North of Switzerland. The preferred host rock is Opalinus clay because of its very low permeability; it is therefore an excellent barrier against nuclide transport. In the three proposed siting regions, Opalinus clay is present in sufficient volumes at a suitable depth. For a L/ILW repository six different possible siting regions were identified, five in Northern Switzerland and one in Central Switzerland. In the three siting regions found for a possible HLW repository, it would also be possible to built a combined repository for both HLW and L/ILW wastes

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...

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)

Barriers of repository under the conditions of underground isolation of heat releasing radioactive waste in permafrost

International Nuclear Information System (INIS)

Kazakov, A.N.; Fedorovich, L.N.

1995-01-01

The main positions and the leading principle of the ensuring of the environmental safety of the method of the underground isolation of radioactive waste in permafrost rock are presented in this work and it is shown here the peculiarities in realization of the principle of the multibarrier protection. It is substantiated here the principle of the optimal time of the capacity for work of the repository's engineered barriers. The possibility of the exclusion of the radionuclides migration beyond the working volume of the repository during the time of the potential danger of radioactive waste is also substantiated in these papers

Factors affecting actinide solubility in a repository for spent fuel, 1

International Nuclear Information System (INIS)

Snellman, Margit

1986-07-01

The main tasks in the study were to get information on the chemical conditions in a repository for spent fuel and information on factors affecting releases of actinides from spent fuel and solubility of actinides in a repository for spent fuel. The work in this field started at the Reactor Laboratory of the Technical Research Centre of Finland (VTT) in 1982. This is a report on the effects on the main parameters, Eh, pH, carbonate, organic compounds, colloids, microbes and radiation on the actinide solubility in the nearfield of the repository. Another task has been to identify available models and reported experience from actinide solubility calculations with different codes. 167 refs

Evolution of geochemical conditions in SFL 3-5

International Nuclear Information System (INIS)

Karlsson, Fred; Lindgren, M.; Skagius, K.; Wiborgh, M.; Engkvist, I.

1999-12-01

The evolution of geochemical conditions in the repository for long-lived low- and intermediate-level waste, SFL 3-5, and in the vicinity of the repository are important when predicting the retention of radionuclides and the long-term stability of engineered barriers. In this study the initial conditions at different repository sites at 300 - 400 m depth, the influence of repository construction and operation, the expected conditions after repository closure and saturation, and the evolution in a long-term perspective are discussed. Groundwaters that are found at these depths have near-neutral pH and are reducing in character, but the composition can vary from saline to non-saline water. The water chemistry in the near-field will mainly be influenced by the composition of the groundwater and by the large amounts of cementitious material that can be found in the repository. Disturbances caused during construction and operation are not expected to be permanent. Studies of old concrete indicate that leaching of concrete is a slow process. The geochemical conditions in the repository are therefore expected to be stable and prevail for hundreds of thousand years. However, the evolution of the surrounding environment may influence the conditions in long-term perspective

Evolution of geochemical conditions in SFL 3-5

Energy Technology Data Exchange (ETDEWEB)

Karlsson, Fred [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Lindgren, M.; Skagius, K.; Wiborgh, M. [Kemakta Konsult AB, Stockholm (Sweden); Engkvist, I. [Barsebaeck Kraft AB (Sweden)

1999-12-01

The evolution of geochemical conditions in the repository for long-lived low- and intermediate-level waste, SFL 3-5, and in the vicinity of the repository are important when predicting the retention of radionuclides and the long-term stability of engineered barriers. In this study the initial conditions at different repository sites at 300 - 400 m depth, the influence of repository construction and operation, the expected conditions after repository closure and saturation, and the evolution in a long-term perspective are discussed. Groundwaters that are found at these depths have near-neutral pH and are reducing in character, but the composition can vary from saline to non-saline water. The water chemistry in the near-field will mainly be influenced by the composition of the groundwater and by the large amounts of cementitious material that can be found in the repository. Disturbances caused during construction and operation are not expected to be permanent. Studies of old concrete indicate that leaching of concrete is a slow process. The geochemical conditions in the repository are therefore expected to be stable and prevail for hundreds of thousand years. However, the evolution of the surrounding environment may influence the conditions in long-term perspective.

Nuclear waste repository simulation experiments

International Nuclear Information System (INIS)

Rothfuchs, T.; Wieczorek, K.; Feddersen, H.K.; Staupendahl, G.; Coyle, A.J.; Kalia, H.; Eckert, J.

1986-12-01

This document is the third joint annual report on the Cooperative German-American 'Brine Migration Tests' that are in progress at the Asse salt mine in the Federal Republic of Germany (FRG). This Government supported mine serves as an underground test facility for research and development (R and D)-work in the field of nuclear waste repository research and simulation experiments. The tests are designed to simulate a nuclear waste repository to measure the effects of heat and gamma radiation on brine migration, salt decrepitation, disassociation of brine, and gases collected. The thermal mechanical behavior of salt, such as room closure, stresses and changes of the properties of salt are measured and compared with predicted behavior. This document covers the following sections: Issues and test objectives: This section presents issues that are investigated by the Brine Migration Test, and the test objectives derived from these issues; test site: This section describes the test site location and geology in the Asse mine; test description: A description of the test configuration, procedures, equipment, and instrumentation is given in this section; actual test chronology: The actual history of the test, in terms of the dates at which major activities occured, is presented in this section. Test results: This section presents the test results observed to data and the planned future work that is needed to complete the test; conclusions and recommendations: This section summarizes the conclusions derived to date regarding the Brine Migration Test. Additional work that would be useful to resolve the issues is discussed. (orig.)

Deep geological isolation of nuclear waste: numerical modeling of repository scale hydrology

International Nuclear Information System (INIS)

Dettinger, M.D.

1980-04-01

The Scope of Work undertaken covers three main tasks, described as follows: (Task 1) CDM provided consulting services to the University on modeling aspects of the study having to do with transport processes involving the local groundwater system near the repository and the flow of fluids and vapors through the various porous media making up the repository system. (Task 2) CDM reviewed literature related to repository design, concentrating on effects of the repository geometry, location and other design factors on the flow of fluids within the repository boundaries, drainage from the repository structure, and the eventual transport of radionucldies away from the repository site. (Task 3) CDM, in a joint effort with LLL personnel, identified generic boundary and initial conditions, identified processes to be modeled, and recommended a modeling approach with suggestions for appropriate simplifications and approximations to the problem and identifiying important parameters necessary to model the processes. This report consists of two chapters and an appendix. The first chapter (Chapter III of the LLL report) presents a detailed description and discussion of the modeling approach developed in this project, its merits and weaknesses, and a brief review of the difficulties anticipated in implementing the approach. The second chapter (Chapter IV of the LLL report) presents a summary of a survey of researchers in the field of repository performance analysis and a discussion of that survey in light of the proposed modeling approach. The appendix is a review of the important physical processes involved in the potential hydrologic transport of radionuclides through, around and away from deep geologic nuclear waste repositories

Influence of the annual flood-pulse on catch per unit effort, condition ...

African Journals Online (AJOL)

Influence of the annual flood-pulse on catch per unit effort, condition and reproduction of Clarias gariepinus from the upper Okavango Delta, Botswana. ... therefore, that conservation efforts should be focused on maintaining natural flow patterns in the face of climate change and potential water extraction schemes upstream.

Review of durability of cementitious engineered barriers in repository environments

International Nuclear Information System (INIS)

Parrott, L.J.; Lawrence, C.D.

1992-01-01

This report is concerned with the durability of cementitious engineered barriers in a repository for low and intermediate level nuclear waste. Following the introduction the second section of the review identifies the environmental conditions associated with a deep, hard rock repository for ILW and LLW that are relevant to the durability of cementitious barriers. Section three examines the microstructure and macrostructure of cementitious materials and considers the physical and chemical processes of radionuclide immobilization. Potential repository applications and compositions of cementitious materials are reviewed in Section four. The main analysis of durability is dealt with in Section five. The different types of cementitious barrier are considered separately and their most probable modes of degradation are analysed. Concluding remarks that highlight critical technical matters are given in Section six. (author)

Geohydrological simulation of a deep coastal repository

International Nuclear Information System (INIS)

Follin, S.

1995-12-01

This conceptual-numerical study treats the dewatering and resaturation phases associated with the construction, use and closure of a coastal nuclear waste repository located at depth in sparsely fractured Baltic Shield rocks. The main objective is to simulate the extent and duration of saline intrusion for a reasonable set of geohydrological assumptions. Long-term changes in the chemical environment associated with saline intrusion may affect the properties of the buffer zone material (bentonite). The first part of the study deals with history matching of a simple model geometry and the second part treats the dewatering and resaturation phases of the simulated repository. The history matching supports the standpoint that the occurrence of saline ground water reflects an ongoing but incomplete Holocene flushing of the Baltic Shield. The drawdown after fifty years of dewatering is highly dependent on the permeability of the excavated damaged zone. If the permeability close the repository is unaltered the entire region between the top side of the model and the repository is more or less partially saturated at the end of the simulation period. The simulations of a fifty year long recovery period suggest that the distribution between fresh and saline ground waters may be quite close to the conditions prior to the dewatering phase already after fifty years of closure despite an incomplete pressure recovery, which is an interesting result considering the objective of the study. 12 refs

Single or multi-repository concept? A personal contribution to the discussion of pros and cons

International Nuclear Information System (INIS)

Closs, K.-D.; Duphorn, K.; Kuehn, K.

2002-01-01

The coalition agreement concluded between the parties in government, i.e. SPD and Alliance 90/The Greens, after the 1998 federal elections provided for an approach to back-end fuel cycle conditions for German nuclear power plants which differed from the practice intended up to that point. Among other things, only one single repository in deep geologic formations is to be available approximately from 2030 on. Exploration of the Gorleben salt dome is to be interrupted because of prevailing doubts while, at the same time, a basic discussion is to be held about potentially suitable host rock varieties and sites. The 'Working Party of Selection Procedures for Repository Sites (AkEnd)' instituted by the federal government is to elaborate scientific siting criteria under these conditions. The authors, who are members of AkEnd, come to the conclusion, based on technical findings and the historical back-end fuel cycle and siting situation in Germany, that a multi-repository concept incorporates substantial advantages. These are the aspects referred to: - Back-end fuel cycle concept: The multi-repository concept offers clearcut advantages in the far advanced Konrad repository project. This is true also against the background of the volume of waste with negligible heat generation to be managed by public authorities. - Long-term safety: Advantages exist, among other things, with respect to technical safety regarding possible compromises in a single-repository concept and the possible restriction of the number of potential sites. - Methods of detection: Spreading the waste over two or more repositories offers benefits in the technical aspects of detection. - Cost: A differentiated assessment of the cost arising in connection with the total amount of waste to be stored in repositories indicates benefits of a multi-repository concept, especially for the public authorities. (orig.) [de

Radionuclides in hydrothermal systems as indicators of repository conditions

International Nuclear Information System (INIS)

Wollenberg, H.A.; Flexser, S.; Smith, A.R.

1990-11-01

Hydrothermal systems in tuffaceous and older sedimentary rocks contain evidence of the interaction of radionuclides in fluids with rock matrix minerals and with materials lining fractures, in settings somewhat analogous to the candidate repository site at Yucca Mountain, NV. Earlier studies encompassed the occurrences of U and Th in a ''fossil'' hydrothermal system in tuffaceous rock of the San Juan Mountains volcanic field, CO. More recent and ongoing studies examine active hydrothermal systems in calderas at Long Valley, CA and Valles, NM. At the Nevada Test Site, occurrences of U and Th in fractured and unfractured rhyolitic tuff that was heated to simulate the introduction of radioactive waste are also under investigation. Observations to date suggest that U is mobile in hydrothermal systems, but that localized reducing environments provided by Fe-rich minerals and/or carbonaceous material concentrate U and thus attenuate its migration. 11 refs., 6 figs., 1 tab

Biosphere modelling for a deep radioactive waste repository: site-specific consideration of the groundwater-soil pathway

International Nuclear Information System (INIS)

Grogan, H.A.; Baeyens, B.; Mueller, H.; Dorp, F. van

1991-07-01

Scenario evaluations indicate that groundwater is the most probable pathway for released radionuclides to reach the biosphere from a deep underground nuclear waste repository. This report considers a small valley in northern Switzerland where the transport of groundwater to surface soil might be possible. The hydrological situation has been examined to allow a system of compartments and fluxes for modelling this pathway with respect to the release of radionuclides from an underground repository to be produced. Assuming present day conditions the best estimate surface soil concentrations are calculated by dividing the soil into two layers (deep soil, surface soil) and assuming an annual upward flux of 10 mm from the groundwater through the two soil layers. A constant unit activity concentration is assumed for the radionuclides in the groundwater. It is concluded that the resultant best estimate values must still be considered to be biased on the conservative side, in view of the fact that the more typical situation is likely to be that no groundwater reaches the surface soil. Upper and lower estimates for the surface soil radionuclide concentrations are based on the parameter perturbation results which were carried out for three key parameters, i.e. precipitation surplus, upward flux and solid-liquid distribution coefficients (K d ). It is noted that attention must be given to the functional relationships which exist between various model parameters. Upper estimates for the surface soil concentration are determined assuming a higher annual upward flux (100 mm) as well as a more conservative K d value compared with the base case. This gives rise to surface soil concentrations more than two orders of magnitude higher than the best estimate values. The lower estimated are more easily assigned assuming that no activity reaches the surface soil via this pathway. (author) 18 figs., 4 tabs., refs

Climate considerations in long-term safety assessments for nuclear waste repositories.

Science.gov (United States)

Näslund, Jens-Ove; Brandefelt, Jenny; Liljedahl, Lillemor Claesson

2013-05-01

For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

Multi criteria decision analysis on a waste repository in Mol

International Nuclear Information System (INIS)

Carle, B.

2005-01-01

In Belgium, the management of radioactive waste is taken care of by ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials. Local partnerships with stakeholders from municipalities in existing nuclear zones were setup to facilitate the dialogue between the repository designers and the local community. Since the establishment of the partnership in Mol, MONA in February 2000, all aspects of a possible near-surface or a deep geological repository are discussed in 4 working groups by around 50 volunteer members. The outcome of the discussions in the partnership can be a shared project, supported by both local stakeholders and ONDRAF/NIRAS, in which the specifications and the conditions needed for establishing a repository in Mol are elaborated. MONA asked the Decision Strategy Research Department of SCK-CEN to organise a Multi Criteria Analysis (MCA) in the context of the deciding between a surface and a deep repository for low level radioactive waste. The objective of the multi criteria analysis is to support a number of representatives of the various working groups within MONA in their selection between two acceptable options for a repository of low level radioactive waste on the territory of Mol. The options are the surface repository developed by the working groups of MONA, and a deep repository in the clay layers underneath the nuclear site of Mol. This study should facilitate the selection between both options, or in case this appears to be difficult, at least to get a well-structured overview of all factors (criteria) of importance to the judgement, and to get insight into the degree in which the various criteria contribute to the selection

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.

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.

Desiderata for healthcare integrated data repositories based on architectural comparison of three public repositories.

Science.gov (United States)

Huser, Vojtech; Cimino, James J

2013-01-01

Integrated data repositories (IDRs) are indispensable tools for numerous biomedical research studies. We compare three large IDRs (Informatics for Integrating Biology and the Bedside (i2b2), HMO Research Network's Virtual Data Warehouse (VDW) and Observational Medical Outcomes Partnership (OMOP) repository) in order to identify common architectural features that enable efficient storage and organization of large amounts of clinical data. We define three high-level classes of underlying data storage models and we analyze each repository using this classification. We look at how a set of sample facts is represented in each repository and conclude with a list of desiderata for IDRs that deal with the information storage model, terminology model, data integration and value-sets management.

Evolution of near-field physico-chemical characteristics of the SFR repository

International Nuclear Information System (INIS)

Savage, D.; Stenhouse, M.; Benbow, S.

2000-08-01

The evaluation of the post-closure performance of the SFR repository needs to consider time dependent evolution of the repository environment. Time-dependent reaction of near-field barriers (cement, steel, bentonite) with saturating groundwater will lead to the development of hyper alkaline repository pore fluids, chemically reducing conditions, and ultimately, the generation of gas through anaerobic corrosion of metals. Cement and concrete will act as chemical conditioning agents to minimise metal corrosion and ultimately, maximise radioelement sorption. The chemical and physical evolution of cement and concrete through reaction with ambient groundwater will thus affect sorption processes through changes in pH, complexing ligands, and solid surface properties. It is desirable that these changes be incorporated into the safety assessment. The sorption behaviour of radionuclides in cementitious systems has been reviewed in detail. The available evidence from experimental work carried out on the influence of organic materials on the sorption behaviour of radionuclides, indicates that most organic degradation products will not affect sorption significantly at the concentrations expected in a cementitious repository. The notable exception to this conclusion involves the degradation products of cellulose and, in particular, polycarboxylic acids represented by iso-saccharinic acid (ISA). Results using ISA indicate a significant reduction in sorption of Pu, by several orders of magnitude, for an ISA concentration of about 10 -3 M. More recent data indicate that the negative effect is not as great, though still significant. Therefore, some scoping calculations are advisable to determine how realistic an ISA concentration of about 10 -3 M would be for the SFR repository and to estimate concentrations of other relevant organic compounds, in particular EDTA, for comparison. Scoping calculations relevant to the longevity of hyper alkaline pore fluid conditions at SFR have been

From the repository to the deep geological repository - and back to the Terrain surface?

International Nuclear Information System (INIS)

Lahodynsky, R.

2011-01-01

How deep is 'safe'? How long is long-term? How and for how long will something be isolated? Which rock, which formation and which location are suitable? A repository constructed for the safekeeping of radioactive or highly toxic wastes can be erected either on the surface, near the surface or underground. Radioactive waste is currently often stored at near-surface locations. The storage usually takes place nearby of a nuclear power plant in pits or concrete tombs (vaults). However, repositories can also be found in restricted areas, e.g. near nuclear weapon production or reprocessing plants (WAA) or nuclear weapons test sites (including Tomsk, Russia, Hanford and Nevada desert, USA), or in extremely low rainfall regions (South Africa). In addition there are disused mines which are now used as underground repositories. Low-level and medium-active (SMA) but also high-level waste (HAA) are stored at these types of sites (NPP, WAA, test areas, former mines). In Russia (Tomsk, Siberia) liquid radioactive waste has been injected into deep geological formations for some time (Minatom, 2001). However, all these locations are not the result of a systematic, scientific search or a holistic process for finding a location, but the result of political decisions, sometimes ignoring scientific findings. Why underground storage is given preference over high-security landfill sites (HSD) often has economic reasons. While a low safety standard can significantly reduce the cost of an above-ground high-security landfill as a waste disposal depot, spending remains high, especially due to the need for capital formation to cover operating expenses after filling the HSD. In the case of underground storage, on the other hand, no additional expenses are required for the period after backfilling. The assumption of lower costs for a deep repository runs through the past decades and coincides with the assumption that the desired ideal underground conditions actually exist and will

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

Applicability of risk-informed criticality methodology to spent fuel repositories

International Nuclear Information System (INIS)

Mays, C.; Thomas, D.A.; Favet, D.

2000-01-01

An important objective of geologic disposal is keeping the fissionable material in a condition so that a self-sustaining nuclear chain reaction (criticality) is highly unlikely. This objective supports the overall performance objective of any repository, which is to protect the health and safety of the public by limiting radiological exposure. This paper describes a risk-informed, performance-based methodology, which combines deterministic and probabilistic approaches for evaluating the criticality potential of high-level waste and spent nuclear fuel after the repository is sealed and permanently closed (postclosure). (authors)

48 CFR 227.7108 - Contractor data repositories.

Science.gov (United States)

2010-10-01

... repositories. 227.7108 Section 227.7108 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS... Technical Data 227.7108 Contractor data repositories. (a) Contractor data repositories may be established when permitted by agency procedures. The contractual instrument establishing the data repository must...

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

Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

Energy Technology Data Exchange (ETDEWEB)

Francis, A.J.; Gillow, J.B.; Giles, M.R. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

1997-03-01

Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 {micro}mol/g cellulose/day in anaerobic samples without nutrients, 0.05 {micro}mol/g cellulose/day in the presence of nutrients, and 0.2 {micro}mol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N{sub 2}O in the headspace (200 {micro}mol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO{sub 2} production to 0.3 {micro}mol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO{sub 2} at a rate of 0.2 {micro}mol/g cellulose/day in the absence of nutrients, and 1 {micro}mol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber.

Perceived risk, trust in government, and response to repository siting in the United States

International Nuclear Information System (INIS)

Kraft, M.E.

1991-01-01

Conflicts over the siting of high-level radioactive waste repositories have been intense and unrelenting. Public and state opposition to implementation of the US Nuclear Waste Policy Act is tied closely to the perception of unacceptably high repository risks and to lack of trust and confidence in governmental agencies, particularly the DOE. This paper explores the relationship of perceived risk, trust in government, and opposition to repository siting in the US in an attempt to clarify the conditions of successful implementation of nuclear waste policy in the decades ahead

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)

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)

The evolution of minor active and toxic gases in repositories

International Nuclear Information System (INIS)

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

1988-09-01

This study has considered a number of toxic and active gases which could potentially form in relatively small amounts in a deep repository for radioactive wastes. It has been concluded that many of these would react under repository conditions or be highly soluble in groundwater. The minor amounts of the inert and relatively insoluble gas krypton-85 would dissolve in a small volume of repository water. The wide range of organic gases and vapours that could form in trace amounts has been shortened to a list of 21 by consideration of their toxicity, volatibility and extent of formation at a landfill site for non-radioactive waste. The amounts of the inert and inactive gas helium formed from α-particles and the decay of tritium will have only a very minor effect on the overall rate of gas production. (author)

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

Global thermo-mechanical effects from a KBS-3 type repository

International Nuclear Information System (INIS)

Hakami, E.; Olofsson, Stig-Olof

1998-01-01

The objective of this study has been to identify the global thermo-mechanical effects in the bedrock hosting a nuclear waste repository. Numerical thermo-mechanical modeling using distinct element models was performed. The number of fracture zones, the heat intensity of the waste, the material properties of the rock mass and the boundary conditions of the models were varied. Different models for multi-level repositories were also analyzed and compared to the main single-level case. Further, the global influence from the excavation of repository tunnels and deposition holes was examined by introducing weaker rock mass material properties in the repository region of one model. The maximum compression stress obtained for the main model is 44 MPa and occurs at the repository level after about 100 years of deposition. Due to thermal expansion, the rock mass displaces upward, and the maximum heave at the ground surface after 1000 years is calculated to be 16 cm. In the area close to the ground surface the horizontal stresses reduce, causing the rock to yield in tension down to a depth of about 80 meters. The fracture zones show opening displacements at shallow depths and closing and shearing at the repository level. The maximum displacements are 0.3-2.5 cm for closing, 0.0-0.8 cm for opening and 0.2-2.2 cm for shearing. The resultant stresses and displacements depend in large part on the assumptions made concerning the heat intensity of the waste. In the main model, an initial heat intensity of 10 W/m 2 is assumed, which gives larger effects than the case with 6 W/m 2 . Another important input parameter for the analysis is the Young's modulus of the rock mass. In the main model, a value of 30 GPa is assumed. Higher values of Young's modulus give larger thermo-mechanical effects. All multi-level repository layouts give rise to higher temperatures than the single-level layout, causing the compressive stresses to increase more at the repository level. The multi

Annual report 2009. Institute of Radiochemistry

International Nuclear Information System (INIS)

Bernhard, G.

2010-01-01

The annual report 2009 of the institute of radiochemistry covers the following topics: Part 1: Actinides (metals) in biosystems; Part 2: Actinides in waste repositories. The research projects were aimed to the basic knowledge about coordination of actinide element transport and transfer in the environment, bacteria influence on the immobilization of heavy metals in water and soils, microbial diversity in biofilms and clays, protein applications for biosensors, dominating processes of soil-liquid interfaces, sorption and surface complexation processes.

Analysis of Turkey’s Institutional Open Repositories: An Example of Dokuz Eylül University Institutional Open Repository

Directory of Open Access Journals (Sweden)

Korhan Levent Ertürk

2012-03-01

Full Text Available After the declaration of the Budapest Open Access Initiative in 2001, institutional open repositories are known as the most important tool of the self archiving, which is also known as green road. There are 26 institutional repositories, which are all compatible to international standards. All the institutional open repositories of Turkey mentioned before are listed in international open archive directories. In this study institutional open repository of Dokuz Eylül University is examined and institutional open repositories of Turkey are discussed.

Progress in the assessment of the corrosion of low and intermediate level waste containers under repository conditions

International Nuclear Information System (INIS)

Marsh, G.P.

1988-08-01

This report describes the methodology which has been developed to assess the long term corrosion of carbon steel and austenitic stainless steel containers for LLW and ILW under repository conditions. In the case of carbon steel the objective is to estimate the metal thickness required as a corrosion allowance in order to attain a container life of up to 300 years. With the stainless steel the aim is to prove their corrosion resistance over the same life-span. Results are reported which given confidence that both classes of steel may be used to produce containers which will last beyond 300 years. Furthermore the level of confidence in this prediction is expected to be increased by the corrosion data which will be obtained in the final year of the current research programme. (author)

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

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

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

Thermodynamic data for copper. Implications for the corrosion of copper under repository conditions

International Nuclear Information System (INIS)

Puigdomenech, I.; Taxen, C.

2000-08-01

The stability of copper canisters has a central role in the safety concept for the planned nuclear spent fuel repository in Sweden. The corrosion of copper canisters will be influenced by the chemical and physical environment in the near-field of the repository, and thermodynamic equilibrium calculations provide the basis for understanding this system. Thermodynamic data have been selected in this work for solids and aqueous species in the system: Cu - H 2 O - H + - H 2 - F - - Cl - - S 2- - SO 4 2- - NO 3 - - NO 2 - - NH 4 + PO 4 3- - CO 3 2+ . For some reactions and compounds, for which no experimental information on temperature effects was available, entropy and heat capacity values have been estimated. The compiled data were used to calculate thermodynamic equilibria for copper systems up to 100 deg C. The stability of copper in contact with granitic groundwaters has been illustrated using chemical equilibrium diagrams, with he following main conclusions: Dissolved sulphide and O 2 in groundwater are the most damaging components for copper corrosion. If available, HS - will react quantitatively with copper to form a variety of sulphides. However, sulphide concentrations in natural waters are usually low, because it forms sparingly soluble solids with transition metals, including Fe(II), which is wide-spread in reducing environments. Chloride can affect negatively copper corrosion. High concentrations (e.g., [Cl - ]TOT > 60 g/l) may be unfavourable for the general corrosion of copper in combination with in the following circumstances: Low pH ( + . The negative effects of Cl - are emphasised at higher temperatures. The chloride-enhancement of general corrosion may be beneficial for localised corrosion: pitting and stress corrosion cracking. The concept of redox potential, E H , has been found to be inadequate to describe copper corrosion in a nuclear repository. The available amounts of oxidants/reductants, and the stoichiometry of the corrosion reactions are

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.

Effect of boundary conditions on thermohydraulic behavior of clay buffer used in nuclear waste repository

International Nuclear Information System (INIS)

Arul Peter, A.; Murugesan, K.; Mamidi, Ganesh; Sharma, Umesh Kumar; Sharma, D. Akanshu; Arora, Puneet

2010-01-01

The use of nuclear energy is increasing dramatically in the world due to the fast depletion of fossil fuels, and hence the nuclear waste disposal and its short and long-term effects are of considerable importance. One of the options considered for nuclear waste disposal is underground nuclear waste repository facility. In this underground nuclear waste disposal system the waste filled canisters are placed in the rock surrounded by an engineered clay barrier and the whole system is buried in the geological formation, which serves as the natural or geological barrier. The important characteristic of the clay barrier is that it should not open up for radiation though it is continuously subjected to heat loading from the canisters. The heat and moisture transport mechanisms through the clay barrier plays an important role in deciding its mechanical strength. Clay behaves as an unsaturated porous material when it is used as a buffer material in nuclear waste facility. The governing equations for heat and moisture transfer through unsaturated porous media are coupled and nonlinear and hence they have to be solved using numerical solution technique. This paper reports the results of a numerical study on heat and moisture transport through a buffer layer made of clay as used in nuclear waste repository. Galerkin's weighted residual finite element method has been employed for the solution of the non-linear coupled governing equations used to represent the heat and moisture transport through unsaturated clay material. A detailed computational procedure has been established for the solution of the non-linear governing equations using Newton-Raphson technique. Initially the code has been validated with available experimental results. Then numerical simulation results were obtained for heat and moisture variations within the buffer material for Dirichlet temperature boundary conditions in the range, 50 deg C 2 2 , with an aim to simulate the boundary conditions which the clay

Project Guarantee 1985. Repository for high-level radioactive waste: construction and operation

International Nuclear Information System (INIS)

Anon.

1985-01-01

An engineering project study aimed at demonstrating the feasibility of constructing a deep repository for high-level waste (Type C repository) has been carried out; the study is based on a model data-set representing typical geological and rock mechanical conditions as found outside the so-called Permocarboniferous basin in the regions under investigation by Nagra in Cantons Aargau, Schaffhausen, Solothurn and Zuerich. The repository is intended for disposal of high-level waste and any intermediate-level waste from re-processing in which the concentration of long-lived alpha-emitters exceeds the permissible limits set for a Type B repository. Final disposal of high-level waste is in subterranean, horizontally mined tunnels and of intermediate-level waste in underground vertical silos. The repository is intended to accomodate a total of around 6'000 HWL-cylinders (gross volume of around 1'200 m3) and around 10'000 m3 of intermediate-level waste. The total excavated volume is around 1'100'000 m3 and a construction time for the whole repository (up to the beginning of emplacement) of around 15 years is expected. For the estimated 50-year emplacement operations, a working team of around 60 people will be needed and a team of around 160 for the simultaneous tunnelling operations and auxiliary work. The project described in the present report permits the conclusion that construction of a repository for high-level radioactive waste and, if necessary, spent fuel-rods is feasible with present-day technology

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.

Effects of long-term exposure of tuffs to high-level nuclear waste-repository conditions. Preliminary report

International Nuclear Information System (INIS)

Blacic, J.; Carter, J.; Halleck, P.; Johnson, P.; Shankland, T.; Andersen, R.; Spicochi, K.; Heller, A.

1982-02-01

Tests have been performed to explore the effects of extended exposure of tuffs from the southwestern portion of the Nevada Test Site to temperatures and pressures similar to those that will be encountered in a high-level nuclear waste repository. Tuff samples ranging from highly welded, nonzeolitized to unwelded, highly zeolitized varieties were subjected to temperatures of 80, 120, and 180 0 C; confining pressures of 9.7 and 19.7 MPa; and water-pore pressures of 0.5 to 19.7 MPa for durations of 2 to 6 months. The following basic properties were measured before and after exposure and compared: tensile strength, uniaxial compressive strength, grain density, porosity, mineralogy, permeability, thermal expansion, and thermal conductivity. Depending on rock type and exposure conditions, significant changes in ambient tensile strength, compressive strength, grain density, and porosity were measured. Mineralogic examination, permeability, and thermal property measurements remain to be completed

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

Dose calculation for accident situations at WWR-S type spent nuclear fuel repository

International Nuclear Information System (INIS)

Margeanu, S.; Florescu, G.

2006-01-01

Full text: The Spent Nuclear Fuel Repository at IFIN-HH Bucharest (SNFR IFIN-HH) consists in four pools, repository hall, radiological monitoring system, ventilation system and auxiliary systems. At the moment the remaining activity in the repository is about 3500 Ci. Despite of the small activity, for emergency preparedness purposes, several accident scenarios, with a non zero probability of occurrence during the repository lifetime, have been postulated. Evaluations of radiological consequences to personnel, general public and environment, for each accident scenario have been performed. The radioactive inventory was evaluated with ORIGEN code from SCALE computer code system and radiological consequences were evaluated with COSYMA computer code. Assumptions for the source term determination, meteorological conditions and release, are presented. The calculated values of doses and risk are also presented. The impact of these accident scenarios on population and environment is also discussed. (authors)

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

Childhood vesicoureteral reflux studies: registries and repositories sources and nosology.

Science.gov (United States)

Chesney, Russell W; Patters, Andrea B

2013-12-01

Despite several recent studies, the advisability of antimicrobial prophylaxis and certain imaging studies for urinary tract infections (UTIs) remains controversial. The role of vesicoureteral reflux (VUR) on the severity and re-infection rates for UTIs is also difficult to assess. Registries and repositories of data and biomaterials from clinical studies in children with VUR are valuable. Disease registries are collections of secondary data related to patients with a specific diagnosis, condition or procedure. Registries differ from indices in that they contain more extensive data. A research repository is an entity that receives, stores, processes and/or disseminates specimens (or other materials) as needed. It encompasses the physical location as well as the full range of activities associated with its operation. It may also be referred to as a biorepository. This report provides information about some current registries and repositories that include data and samples from children with VUR. It also describes the heterogeneous nature of the subjects, as some registries and repositories include only data or samples from patients with primary reflux while others also include those from patients with syndromic or secondary reflux. Copyright © 2012 Journal of Pediatric Urology Company. All rights reserved.

Near-surface hydrogeological model of Laxemar. Open repository - Laxemar 1.2

Energy Technology Data Exchange (ETDEWEB)

Bosson, Emma

2006-07-15

This report presents the methodology and the results from the modelling of an open final repository for spent nuclear fuel in Laxemar. Thus, the present work analyses the hydrological effects of the planned repository during the construction and operational phases when it is open, i.e. air-filled, and hence may cause a disturbance of the hydrological conditions in the surroundings. The numerical modelling is based on the conceptual and descriptive model presented in the version 1.2 Site Descriptive Model (SDM) for Laxemar. The modelling was divided into three steps. The first step was to update the L1.2 version model for hydrology and near surface hydrogeology, the main updates were related to the hydraulic properties of the bedrock and the size of the model area. The next step was to describe the conditions for the introductory construction by implementing the access tunnel and shafts to the model. The third step aimed at describing the consequences on the surface hydrology caused by an open repository. A sensitivity analysis that aimed to investigate the sensitivity of the model to the properties of the upper bedrock and the properties in the interface between the Quaternary deposits and the bedrock was performed as a part of steps two and three. The model covers an area of 19 km{sup 2}. In the Quaternary deposits, the surface water divides are assumed to coincide with the groundwater divides, thus a no-flow boundary condition is used at the horizontal boundaries. The transient top boundary condition uses meteorological data gathered at a local SKB station at Aespoe during 2004. The bottom boundary condition and the horizontal boundary condition in the bedrock is a steady state head boundary condition taken from the open repository modelling of the bedrock performed as a parallel activity with the modelling tool DarcyTools. The vertical extent of the model is from the ground surface to 150 m below sea level. Since the repository will be built at 450 m below sea

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

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.

Annual Report 2003

International Nuclear Information System (INIS)

2004-01-01

The following topics are dealt with: Current situation in radioactive waste storage/disposal; Major activities and results (Dukovany radioactive waste repository; Richard and Bratrstvi radioactive waste repositories; Monitoring of the repositories and of their environmental impacts); Preparatory activities for a deep geological disposal facility (Site selection; Major stages of deep geological disposal facility selection programme; Results of Stage 1 - site assessment; Step 1: Excluding unsuitable sites; Step 2: Selection of sites with suitable geologic conditions; Step 3: Exclusion of sites based on exclusion criteria; Step 4: Assessment of strengths; Results of Stage 2 - short-list of sites; Design activities, proposal for engineered barriers, safety assessment; Supplementary research projects); Administrative, technical and law-related activities (Licensing; Account-keeping of radioactive wastes and nuclear material taken for storage/disposal; Administration of payments to the nuclear account; Supervision of accumulation of decommissioning funds; Public relations; Internal auditing; International cooperation; Quality assurance and quality control); and Financial statements. (P.A.)

Rock mass modification around a nuclear waste repository in welded tuff

International Nuclear Information System (INIS)

Mack, M.G.; Brandshaug, T.; Brady, B.H.

1989-08-01

This report presents the results of numerical analyses to estimate the extent of rock mass modification resulting from the presence of a High Level Waste (HLW) repository. Changes in rock mass considered are stresses and joint deformations resulting from disposal room excavation and thermal efffects induced by the heat generated by nuclear waste. rock properties and site conditions are taken from the Site Characterization Plan Conceptual Design Report for the potential repository site at Yucca Mountain, Nevada. Analyses were conducted using boundary element and distinct element methods. Room-scale models and repository-scale models were investigated for up to 500 years after waste emplacement. Results of room-scale analyses based on the thermoelastic boundary element model indicate that a zone of modified rock develops around the disposal rooms for both vertical and horizontal waste emplacement. This zone is estimated to extend a distance of roughly two room diameters from the room surface. Results from the repository-scale model, which are based on the thermoelastic boundary element model and the distinct element model, indicate a zone with modified rock mass properties starting approximately 100 m above and below the repository, with a thickness of approximately 200 m above and 150 m below the repository. Slip-prone subhorizontal features are shown to have a substantial effect on rock mass response. The estimates of rock mass modification reflect uncertainties and simplifying assumptions in the models. 32 refs., 57 figs., 1 tab

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

Biogeochemistry of Redox at Repository Depth and Implications for the Canister

Energy Technology Data Exchange (ETDEWEB)

Bath, Adrian; Hermansson, Hans-Peter

2009-08-15

The present groundwater chemical conditions at the candidate sites for a spent nuclear fuel repository in Sweden (the Forsmark and Laxemar sites) and processes affecting its future evolution comprise essential conditions for the evaluation of barrier performance and long-term safety. This report reviews available chemical sampling information from the site investigations at the candidate sites, with a particular emphasis on redox active groundwater components and microbial populations that influence redox affecting components. Corrosion of copper canister material is the main barrier performance influence of redox conditions that is elaborated in the report. One section addresses native copper as a reasonable analogue for canister materials and another addresses the feasibility of methane hydrate ice accumulation during permafrost conditions. Such an accumulation could increase organic carbon availability in scenarios involving microbial sulphate reduction. The purpose of the project is to evaluate and describe the available knowledge and data for interpretation of geochemistry, microbiology and corrosion in safety assessment. A conclusive assessment of the sufficiency of information can, however, only be done in the future context of a full safety assessment. The authors conclude that SKB's data and models for chemical and microbial processes are adequate and reasonably coherent. The redox conditions in the repository horizon are predominantly established through the SO{sub 4}2-/HS- and Fe3+/Fe2+ redox couples. The former may exhibit a more significant buffering effect as suggested by measured Eh values, while the latter is associated with a lager capacity due to abundant Fe(II) minerals in the bedrock. Among a large numbers of groundwater features considered in geochemical equilibrium modelling, Eh, pH, temperature and concentration of dissolved sulphide comprise the most essential canister corrosion influences. Groundwater sulphide may originate from

Biogeochemistry of Redox at Repository Depth and Implications for the Canister

International Nuclear Information System (INIS)

Bath, Adrian; Hermansson, Hans-Peter

2009-08-01

The present groundwater chemical conditions at the candidate sites for a spent nuclear fuel repository in Sweden (the Forsmark and Laxemar sites) and processes affecting its future evolution comprise essential conditions for the evaluation of barrier performance and long-term safety. This report reviews available chemical sampling information from the site investigations at the candidate sites, with a particular emphasis on redox active groundwater components and microbial populations that influence redox affecting components. Corrosion of copper canister material is the main barrier performance influence of redox conditions that is elaborated in the report. One section addresses native copper as a reasonable analogue for canister materials and another addresses the feasibility of methane hydrate ice accumulation during permafrost conditions. Such an accumulation could increase organic carbon availability in scenarios involving microbial sulphate reduction. The purpose of the project is to evaluate and describe the available knowledge and data for interpretation of geochemistry, microbiology and corrosion in safety assessment. A conclusive assessment of the sufficiency of information can, however, only be done in the future context of a full safety assessment. The authors conclude that SKB's data and models for chemical and microbial processes are adequate and reasonably coherent. The redox conditions in the repository horizon are predominantly established through the SO 4 2- /HS - and Fe 3+ /Fe 2+ redox couples. The former may exhibit a more significant buffering effect as suggested by measured Eh values, while the latter is associated with a lager capacity due to abundant Fe(II) minerals in the bedrock. Among a large numbers of groundwater features considered in geochemical equilibrium modelling, Eh, pH, temperature and concentration of dissolved sulphide comprise the most essential canister corrosion influences. Groundwater sulphide may originate from sulphide

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

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

Analysis of the processes defining radionuclide migration from deep geological repositories in porous medium

International Nuclear Information System (INIS)

Brazauskaite, A.; Poskas, P.

2004-01-01

Due to the danger of exposure arising from long-lived radionuclides to humans and environment, spent nuclear fuel (SNF) and high level waste (HLW) are not allowed to be disposed of in near surface repositories. There exists an international consensus that such high level and long-lived radioactive wastes are best disposed of in geological repositories using a system of engineered and natural barriers. At present, the geological repository of SNF and HLW has not been realized yet in any country but there is a lot of experience in the assessment of radionuclide migration from deep repositories, investigations of different processes related to the safety of a disposal system. The aim of this study was to analyze the processes related to the radionuclide migration from deep geological repositories in porous medium such as SNF matrix dissolution, release mechanism of radionuclides from SNF matrix, radionuclide solubility, sorption, diffusive, advective transport of radionuclides from the canister and through the engineered and natural barriers. It has been indicated that SNF matrix dissolution, radionuclide solubility and sorption are sensitive to ambient conditions prevailing in the repository. The approaches that could be used for modeling the radionuclide migration from deep repositories in porous medium are also presented. (author)

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.

Establishment of the Slovenian Universities' Repositories and of the National Open Science Portal

Directory of Open Access Journals (Sweden)

Milan Ojsteršek

2014-12-01

Full Text Available AbstractThe paper presents the legal, organisational and technical perspectives regarding the implementation of the Slovenian national open access infrastructure for electronic theses and dissertations as well as for research publications. The infrastructure consists of four institutional repositories and a national portal that aggregates content from the university repositories and other Slovenian archives in order to provide a common search engine, recommendation of similar publications, and similar text detection. We have developed the software which is integrated with the universities' information and authentication systems and with the COBISS.SI. During the project the necessary legal background was defined and processes for mandatory submission of electronic theses and dissertations as well as of research publications were designed. The processes for data exchange between the institutional repositories and the national portal, and the processes for similar text detection and recommendation system were established. Bilingual web and mobile applications, a recommendation system and the interface suitable for persons with disabilities are provided to the users from around the world. The repositories are an effective promotion tool for universities and their researchers. It is expected that they will improve the recognition of Slovenian universities in the world. The complex national open access infrastructure with similar text detection support and integration with other systems will enable the storage of almost eighty percent of peer-reviewed scientific papers, annually published by Slovenian researchers. The majority of electronic theses and dissertations yearly produced at the Slovenian higher education institutions will also be accessible.

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.

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)

Model of evolution of radioactive waste repositories and their influence on the resource-ecological safety of an adjoining territories

International Nuclear Information System (INIS)

Angelova, R.; Sandul, G.A.; Sen'ko, T.Ya.

2002-01-01

In this paper it is considered the mathematical model of evolution of radioactive waste (RAW) repositories and their influence on the resource-ecological safety (RES) and sustainable development of an adjoining territories. Heart of considered model consists of that RAW repository is considered as a system with two processes proceeding in parallel: deterioration of repository buildings, equipment etc. enlarging resource-ecological danger (RED) on account of probability increase (risk increase) of emergency conditions; natural decay of RAW being in repository that lead to RED decrease. Considered model allows to learn RAW repositories evolution in given time interval and to analyze their behavior at its different stages depending on state of repositories, e.g., their modernization or other events as well as to define periods of RAW repositories peak danger for environment

Use of a United States mid-Pacific Island territory for a Pacific Island Repository System (PIRS): Extended summary

International Nuclear Information System (INIS)

Forsberg, C.W.

1987-08-01

The concept of using a mid-ocean island for a geologic high-level waste repository was investigated. The technical advantages include geographical isolation and near-infinite ocean dilution as a backup to repository geological waste isolation. The institutional advantages are reduced siting problems and the potential of creating an international waste repository. Establishment of international waste repository would allow cost sharing, aid US nonproliferation goals, and assure proper disposal of spent fuel from developing countries. The major uncertainties in this concept are rock conditions at waste disposal depths and costs. 13 refs., 2 tabs

Multiscale Thermohydrologic Model Analyses of Heterogeneity and Thermal-Loading Factors for the Proposed Repository at Yucca Mountain

International Nuclear Information System (INIS)

Glascoe, L.G.; Buscheck, T.A.; Gansemer, J.; Sun, Y.; Lee, K.

2002-01-01

The MultiScale ThermoHydrologic Model (MSTHM) predicts thermohydrologic (TH) conditions in emplacement drifts and the adjoining host rock throughout the proposed nuclear-waste repository at Yucca Mountain. The MSTHM is a computationally efficient approach that accounts for TH processes occurring at a scale of a few tens of centimeters around individual waste packages and emplacement drifts, and for heat flow at the multi-kilometer scale at Yucca Mountain. The modeling effort presented here is an early investigation of the repository and is simulated at a lower temperature mode and with a different panel loading than the repository currently being considered for license application. We present these recent lower temperature mode MSTHM simulations that address the influence of repository-scale thermal-conductivity heterogeneity and the influence of preclosure operational factors affecting thermal-loading conditions. We can now accommodate a complex repository layout with emplacement drifts lying in non-parallel planes using a superposition process that combines results from multiple mountain-scale submodels. This development, along with other improvements to the MSTHM, enables more rigorous analyses of preclosure operational factors. These improvements include the ability to (1) predict TH conditions on a drift-by-drift basis, (2) represent sequential emplacement of waste packages along the drifts, and (3) incorporate distance- and time-dependent heat-removal efficiency associated with drift ventilation. Alternative approaches to addressing repository-scale thermal-conductivity heterogeneity are investigated. We find that only one of the four MSTHM submodel types needs to incorporate thermal-conductivity heterogeneity. For a particular repository design, we find that the most influential parameters are (1) percolation-flux distribution, (2) thermal-conductivity heterogeneity within the host-rock units, (3) the sequencing of waste-package emplacement, and (4) the

Aquatic ecosystem characterisation strategy at a repository site

Energy Technology Data Exchange (ETDEWEB)

Kangasniemi, Ville; Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, 00420 Helsinki (Finland); Kirkkala, Teija [Pyhaejaervi Institute, Sepaentie 7, 27500 Kauttua (Finland); Koivunen, Sari [Water and Environment Research of South-West Finland, Telekatu 16, 20360 Turku (Finland)

2014-07-01

Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. According to regulatory requirements, the safety assessment for the repository should have an assessment timeframe of several millennia. Due to the post-glacial land uplift, the relatively shallow sea areas around Olkiluoto Island will change gradually to lakes, rivers and terrestrial areas. As there are no limnic systems at present Olkiluoto site, the reference area was delineated and reference lakes and rivers were selected as an analogue. For the modelling of the transport and accumulation of possible radionuclide releases in the surface environment, aquatic ecosystems were identified and divided into biotopes. Despite the number of available templates, the division of aquatic environment for the biosphere assessment of the Olkiluoto spent fuel repository was necessary to made separately. In this contribution, the processes behind the identification of aquatic ecosystems (e.g. legislation, physical and chemical properties) together with the biotope selection methodology (e.g. light and bottom conditions) and the challenges related to the amount of variable input parameters for each biotope in the modelling are presented. (authors)

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

An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

International Nuclear Information System (INIS)

King, Fraser; Lilja, Christina; Pedersen, Karsten; Pitkaenen, Petteri; Vaehaenen, Marjut

2010-12-01

Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid

An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

Energy Technology Data Exchange (ETDEWEB)

King, F. [Integrity Corrosion Consulting Limited (Canada); Lilja, C. [Svensk Kaernbraenslehantering AB, Stockholm (Sweden); Pedersen, K. [Microbial Analytics Sweden AB, Molnlycke (Sweden); Pitkaenen, P.; Vaehaenen, M.

2012-07-15

Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid. (orig.)

An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

Energy Technology Data Exchange (ETDEWEB)

King, Fraser (Integrity Corrosion Consulting Limited (Canada)); Lilja, Christina (Svensk Kaernbraenslehantering AB (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden)); Pitkaenen, Petteri; Vaehaenen, Marjut (Posiva Oy (Finland))

2010-12-15

Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid

An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

International Nuclear Information System (INIS)

King, F.; Lilja, C.; Pedersen, K.; Pitkaenen, P.; Vaehaenen, M.

2012-07-01

Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid. (orig.)

DOCUMENTATION OF NATIONAL WEATHER CONDITIONS AFFECTING LONG-TERM DEGRADATION OF COMMERCIAL SPENT NUCLEAR FUEL AND DOE SPENT NUCLEAR FUEL AND HIGH-LEVEL WASTE

International Nuclear Information System (INIS)

W. L. Poe, Jr.; P.F. Wise

1998-01-01

The U.S. Department of Energy (DOE) is preparing a proposal to construct, operate 2nd monitor, and eventually close a repository at Yucca Mountain in Nye County, Nevada, for the geologic disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW). As part of this effort, DOE has prepared a viability assessment and an assessment of potential consequences that may exist if the repository is not constructed. The assessment of potential consequences if the repository is not constructed assumes that all SNF and HLW would be left at the generator sites. These include 72 commercial generator sites (three commercial facility pairs--Salem and Hope Creek, Fitzpatrick and Nine Mile Point, and Dresden and Morris--would share common storage due to their close proximity to each other) and five DOE sites across the country. DOE analyzed the environmental consequences of the effects of the continued storage of these materials at these sites in a report titled Continued Storage Analysis Report (CSAR; Reference 1 ) . The CSAR analysis includes a discussion of the degradation of these materials when exposed to the environment. This document describes the environmental parameters that influence the degradation analyzed in the CSAR. These include temperature, relative humidity, precipitation chemistry (pH and chemical composition), annual precipitation rates, annual number of rain-days, and annual freeze/thaw cycles. The document also tabulates weather conditions for each storage site, evaluates the degradation of concrete storage modules and vaults in different regions of the country, and provides a thermal analysis of commercial SNF in storage

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)

Principal organic materials in a repository for spent nuclear fuel

International Nuclear Information System (INIS)

Hallbeck, Lotta

2010-01-01

The largest pool of organic material in a repository at closure is the organic material in the bentonite in buffer and backfill. It is impossible to make any assumptions as to how much of this material will be available for biodegradation, since the character of the material is unknown. However, it is unlikely that this organic material can dissolve in groundwater unless the bentonite loses its swelling capacity. The second largest pool will be the biofilms formed on the rock surfaces. This assumption presupposes that no cleaning is undertaken before repository closure. The third largest pool is the organic material produced by microorganisms using hydrogen from the anaerobic corrosion of iron in steel as an energy source. The following provides summary descriptions of the different pools of organic material that will remain in the repository: 1. Microorganisms. Their effect would mainly be to reduce the redox potential soon after repository closure. They may contribute to the depletion of the oxygen entrapped during repository construction, an effect that would not jeopardise repository stability. If the dominant microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to the formation of HS - . The produced sulphide could corrode the copper canisters under anaerobic conditions if it reaches them. Another effect of microorganisms would be to increase the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the small amounts of such substances. 2. Materials in the ventilation air. Their effect will probably be to help maintain reducing conditions in the area, although this effect will likely be minimal or negligible. 3. Construction materials. Among these materials, we emphasise the organic materials present in concrete, asphalt, bentonite, and wood. Hydrocarbons from asphalt may help reduce

Principal organic materials in a repository for spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Hallbeck, Lotta (Microbial Analytics Sweden AB, Moelnlycke (Sweden))

2010-01-15

The largest pool of organic material in a repository at closure is the organic material in the bentonite in buffer and backfill. It is impossible to make any assumptions as to how much of this material will be available for biodegradation, since the character of the material is unknown. However, it is unlikely that this organic material can dissolve in groundwater unless the bentonite loses its swelling capacity. The second largest pool will be the biofilms formed on the rock surfaces. This assumption presupposes that no cleaning is undertaken before repository closure. The third largest pool is the organic material produced by microorganisms using hydrogen from the anaerobic corrosion of iron in steel as an energy source. The following provides summary descriptions of the different pools of organic material that will remain in the repository: 1. Microorganisms. Their effect would mainly be to reduce the redox potential soon after repository closure. They may contribute to the depletion of the oxygen entrapped during repository construction, an effect that would not jeopardise repository stability. If the dominant microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to the formation of HS-. The produced sulphide could corrode the copper canisters under anaerobic conditions if it reaches them. Another effect of microorganisms would be to increase the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the small amounts of such substances. 2. Materials in the ventilation air. Their effect will probably be to help maintain reducing conditions in the area, although this effect will likely be minimal or negligible. 3. Construction materials. Among these materials, we emphasise the organic materials present in concrete, asphalt, bentonite, and wood. Hydrocarbons from asphalt may help reduce

Hydrogeological modelling for assessment of radionuclide release scenarios for the repository system 2012

Energy Technology Data Exchange (ETDEWEB)

Hartley, L.; Hoek, J.; Swan, D.; Appleyard, P.; Baxter, S.; Roberts, D.; Simpson, T. [AMEC (United Kingdom)

2013-07-15

Posiva Oy is responsible for implementing the programme for geological disposal of spent nuclear fuel produced by its owners Teollisuuden Voima Oyj (TVO) and Fortum Power and Heat Oy in Finland. Olkiluoto in Eurajoki has been selected as the primary site for the repository, subject to further detailed investigation which is currently focused on the construction of an underground rock characterisation and research facility (the ONKALO). An essential part of the assessment of long-term safety of a repository is the analysis of groundwater flow since it is the only means of transport of radionuclides to the biosphere (besides human intrusion). The analysis of long-term safety for a KBS-3 concept requires as input a description of details of the groundwater flow around and through components of the engineered barrier system as well as details of the groundwater pathway to the biosphere during the current temperate climate period, as well as indications of behaviour under future climate periods such as glacial conditions. This report describes the groundwater flow modelling study performed to provide some of the necessary inputs required by Safety Assessment (i.e. radionuclide transport analysis). Underlying this study is the understanding of the site developed during the site investigations as summarised in the site descriptive model (SDM), and in particular the description of Olkiluoto Hydrogeological DFN model (Hydro-DFN). The main focus of this study is the temperate climate period, i.e. the evolution over the next 10,000 years, but the hydrogeological situation under various glacial climate conditions is also evaluated. Primary outputs of the study are repository performance measures relating to: the distributions of groundwater flow around the deposition holes; deposition tunnels and through the EDZ; flow-related transport resistance along groundwater pathways from the repository to the surface; and their the exit locations. Other analyses consider the

Hydrogeological modelling for assessment of radionuclide release scenarios for the repository system 2012

International Nuclear Information System (INIS)

Hartley, L.; Hoek, J.; Swan, D.; Appleyard, P.; Baxter, S.; Roberts, D.; Simpson, T.

2013-07-01

Posiva Oy is responsible for implementing the programme for geological disposal of spent nuclear fuel produced by its owners Teollisuuden Voima Oyj (TVO) and Fortum Power and Heat Oy in Finland. Olkiluoto in Eurajoki has been selected as the primary site for the repository, subject to further detailed investigation which is currently focused on the construction of an underground rock characterisation and research facility (the ONKALO). An essential part of the assessment of long-term safety of a repository is the analysis of groundwater flow since it is the only means of transport of radionuclides to the biosphere (besides human intrusion). The analysis of long-term safety for a KBS-3 concept requires as input a description of details of the groundwater flow around and through components of the engineered barrier system as well as details of the groundwater pathway to the biosphere during the current temperate climate period, as well as indications of behaviour under future climate periods such as glacial conditions. This report describes the groundwater flow modelling study performed to provide some of the necessary inputs required by Safety Assessment (i.e. radionuclide transport analysis). Underlying this study is the understanding of the site developed during the site investigations as summarised in the site descriptive model (SDM), and in particular the description of Olkiluoto Hydrogeological DFN model (Hydro-DFN). The main focus of this study is the temperate climate period, i.e. the evolution over the next 10,000 years, but the hydrogeological situation under various glacial climate conditions is also evaluated. Primary outputs of the study are repository performance measures relating to: the distributions of groundwater flow around the deposition holes; deposition tunnels and through the EDZ; flow-related transport resistance along groundwater pathways from the repository to the surface; and their the exit locations. Other analyses consider the

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

Mechanical stability of repository tunnels and factors to be considered for determining tunnel spacing

International Nuclear Information System (INIS)

Takeuchi, Kunifumi

1994-01-01

Kristallin-1 organized by Nagra is currently advanced as a synthetic project regarding a high level radioactive waste (HLW) repository in Switzerland. Its host rock is granitic rocks, and the potential siting area is located in northern Switzerland. The objective of this project is to demonstrate the long term safety of a HLW repository under more site-specific conditions than before. As the detailed geological data were investigated, the average size of undisturbed crystalline rock blocks is limited horizontally to about several hundred meter, therefore, the HLW repository area must be divided into several panels to avoid fracture zones. It is necessary to make tunnel spacing as small as possible for the purpose of reasonably designing the entire layout of repository tunnels. The main factors to be considered for determining repository tunnel spacing are listed. Rock mass modeling, rock mass material properties, the analysis model and parameters, the numerical analysis of repository tunnel stability and its main conclusion are reported. The numerical analysis of the temperature distribution in near field was carried out. Tunnel spacing should be set more than 20 m in view of the maximum temperature. (K.I.)

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

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

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

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

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.

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

A review of sorption of radionuclides under the near- and far-field conditions of an underground radioactive waste repository. Pt. 2

International Nuclear Information System (INIS)

Berry, J.A.

1992-01-01

This report, a bibliography, has been prepared, presenting work carried out world-wide since 1970 on the sorption of radionuclides under near- and far-field conditions. Work has been included where the results are relevant to the disposal of low- and intermediate-level radioactive waste in a cementitious repository in the UK. The bibliography has been prepared using the INIS database and includes eight hundred references, listed both by subject and by country. In addition to these indexes, full abstracts are presented in reverse chronological order. A brief description of the relevance and measurement of sorption parameters is included. (author)

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

second part of the study stress paths obtained from the thermo-mechanical analysis were used as boundary conditions in DFN-DEM analysis of six DFN models at the repository level. Increases of permeability up to a factor of four were observed during thermal loading history and shear dilation of fractures was not recovered after cooling of the repository. An understanding of the stress path and potential areas of slip induced shear dilation and related permeability changes during the lifetime of a repository for spent nuclear fuel is of utmost importance for analysing long-term safety. The result of this study will assist in identifying critical areas around a repository where fracture shear slip is likely to develop. The present study is restricted to rock mass conditions found at repository level in SKB's Forsmark site

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

second part of the study stress paths obtained from the thermo-mechanical analysis were used as boundary conditions in DFN-DEM analysis of six DFN models at the repository level. Increases of permeability up to a factor of four were observed during thermal loading history and shear dilation of fractures was not recovered after cooling of the repository. An understanding of the stress path and potential areas of slip induced shear dilation and related permeability changes during the lifetime of a repository for spent nuclear fuel is of utmost importance for analysing long-term safety. The result of this study will assist in identifying critical areas around a repository where fracture shear slip is likely to develop. The present study is restricted to rock mass conditions found at repository level in SKB's Forsmark site

Aespoe Hard Rock Laboratory. Annual report 1997

International Nuclear Information System (INIS)

1998-05-01

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

Thermodynamic data for copper. Implications for the corrosion of copper under repository conditions

Energy Technology Data Exchange (ETDEWEB)

Puigdomenech, I. [Royal Inst. of Tech., Stockholm (Sweden); Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden)

2000-08-01

The stability of copper canisters has a central role in the safety concept for the planned nuclear spent fuel repository in Sweden. The corrosion of copper canisters will be influenced by the chemical and physical environment in the near-field of the repository, and thermodynamic equilibrium calculations provide the basis for understanding this system. Thermodynamic data have been selected in this work for solids and aqueous species in the system: Cu - H{sub 2}O - H{sup +} - H{sub 2} - F{sup -} - Cl{sup -} - S{sup 2-} - SO{sub 4}{sup 2-} - NO{sub 3}{sup -} - NO{sub 2}{sup -} - NH{sub 4}{sup +} PO{sub 4}{sup 3-} - CO{sub 3}{sup 2+} . For some reactions and compounds, for which no experimental information on temperature effects was available, entropy and heat capacity values have been estimated. The compiled data were used to calculate thermodynamic equilibria for copper systems up to 100 deg C. The stability of copper in contact with granitic groundwaters has been illustrated using chemical equilibrium diagrams, with he following main conclusions: Dissolved sulphide and O{sub 2} in groundwater are the most damaging components for copper corrosion. If available, HS{sup -} will react quantitatively with copper to form a variety of sulphides. However, sulphide concentrations in natural waters are usually low, because it forms sparingly soluble solids with transition metals, including Fe(II), which is wide-spread in reducing environments. Chloride can affect negatively copper corrosion. High concentrations (e.g., [Cl{sup -}]TOT > 60 g/l) may be unfavourable for the general corrosion of copper in combination with in the following circumstances: Low pH (< 4 at 25 deg C, or < 5 at 100 deg C). The presence of other oxidants than H{sup +}. The negative effects of Cl{sup -} are emphasised at higher temperatures. The chloride-enhancement of general corrosion may be beneficial for localised corrosion: pitting and stress corrosion cracking. The concept of redox potential, E

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

Aespoe Hard Rock Laboratory. Annual report 1996

International Nuclear Information System (INIS)

1997-04-01

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

Aespoe Hard Rock Laboratory. Annual report 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-04-01

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

Evolution of near-field physico-chemical characteristics of the SFR repository

Energy Technology Data Exchange (ETDEWEB)

Savage, D [Quintessa Ltd., Nottingham (United Kingdom); Stenhouse, M [Monitor Scientific LLC, Denver, CO (United States); Benbow, S [Quintessa Ltd., Henley-on-Thames (United Kingdom)

2000-08-01

The evaluation of the post-closure performance of the SFR repository needs to consider time dependent evolution of the repository environment. Time-dependent reaction of near-field barriers (cement, steel, bentonite) with saturating groundwater will lead to the development of hyper alkaline repository pore fluids, chemically reducing conditions, and ultimately, the generation of gas through anaerobic corrosion of metals. Cement and concrete will act as chemical conditioning agents to minimise metal corrosion and ultimately, maximise radioelement sorption. The chemical and physical evolution of cement and concrete through reaction with ambient groundwater will thus affect sorption processes through changes in pH, complexing ligands, and solid surface properties. It is desirable that these changes be incorporated into the safety assessment. The sorption behaviour of radionuclides in cementitious systems has been reviewed in detail. The available evidence from experimental work carried out on the influence of organic materials on the sorption behaviour of radionuclides, indicates that most organic degradation products will not affect sorption significantly at the concentrations expected in a cementitious repository. The notable exception to this conclusion involves the degradation products of cellulose and, in particular, polycarboxylic acids represented by iso-saccharinic acid (ISA). Results using ISA indicate a significant reduction in sorption of Pu, by several orders of magnitude, for an ISA concentration of about 10{sup -3} M. More recent data indicate that the negative effect is not as great, though still significant. Therefore, some scoping calculations are advisable to determine how realistic an ISA concentration of about 10{sup -3} M would be for the SFR repository and to estimate concentrations of other relevant organic compounds, in particular EDTA, for comparison. Scoping calculations relevant to the longevity of hyper alkaline pore fluid conditions at SFR

Aespoe Hard Rock Laboratory. Annual Report 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-06-15

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

Aespoe Hard Rock Laboratory. Annual Report 2005

International Nuclear Information System (INIS)

2006-06-01

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

A safeguards approach for a closed geological repository for spent fuel

International Nuclear Information System (INIS)

Meer, K. van der; Carchon, R.

1999-01-01

After closure of a geological repository a diversion of fissile material can only take place by excavating spent fuel containers and bringing them to the surface. Therefore mining activities are required, either by reopening the original shaft, by creating a new shaft or by approaching the containers underground via a neighbouring mine The recovery time of the stored spent fuel plays an important role in the determination of the timeliness criterion and, therefore, the inspection frequency of the site. Obviously, this frequency can create a financial constraint due to the infinite character of the spent fuel storage in a geological repository. Anomalies for detection of a possible diversion are undeclared mining activities. The safeguards approach has to assure Continuity Of Knowledge (COK) of the fissile material. By consequence, a safeguards approach that is developed for a closed repository, is influenced by the safeguards approach applied to an open. repository and a conditioning facility. A closed repository is verified by DIV. To perform the DIV satellite monitoring could be performed for surface verification and e.g. seismic techniques could be used for verification that no undeclared mining activities underground take place. Visual inspections of the site by inspectors have to reveal concealment methods used by a potential diverter. These measures should guarantee that the disposed spent fuel remains untouched. (author)

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)

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.

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

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)

Open DOAR the Directory of Open Access Repositories

CERN Multimedia

CERN. Geneva

2005-01-01

The last year has seen wide-spread growth in the idea of using open access repositories as a part of a research institution's accepted infrastructure. Policy development from institutions and funding bodies has also supported the growth of the repository network. The next stage of expansion will be in the provision of services and cross-repository facilities and resources. Of course, it is hoped that these will then establish a feed-back loop to encourage repository population and further repository establishment, as the potential of open access to research materials is realised. The growth of repositories has been organic, with a variety of different repositories based in departments, institutions, funding agencies or subject communities, with a range of content, both in type and subject. Existing repositories are expanding their holdings, from eprints to associated research data-sets, or with learning objects and multimedia material. This presentation will look at the development of the Directory of Open Ac...

Evaluasi Website Repositori Institusi Universitas Surabaya

Directory of Open Access Journals (Sweden)

Amirul Ulum

2015-11-01

Full Text Available The  development  of  institutional  repositories  (IRs  in Indonesia within the broader framework of open access has significant impact on preserving intellectual capital and scholarly communication. Institutional  repositories  play  a  fundamental  role  in  centralizing, preserving,  and  making  accessible  institution’s  intellectual  capital. Evaluation of the system is to determine the functionality the system to meet the users need. Using a descriptive analysis this study wants to evaluate institutional repositories of University of Surabaya. The result is usefull for institution to develop the repository systems.

Coupled thermo-mechanical analysis of granite for high-level radioactive waste repository

International Nuclear Information System (INIS)

Liu Wengang; Wang Ju; Zhou Hongwei; Jiang Pengfei; Yang Chunhe

2008-01-01

High-level radioactive wastes (HLW) repository is a special deep underground engineering, and in the stages of site selection, designing, constructing ,the stability evaluation, lots of important rock mechanics problems need to be resolved. During the decay of nuclear waste, enormous thermal energy was released and temperature variation caused dynamic distribution of stress and deformation field of surrounding rock of repository. BeiShan region of Gansu province was selected to be the repository field in the future, it is of practical significance to do research on granite in this region. Based on the concept model of HLW repository, this thesis calculates temperature field, stress field and deformation field of HLW repository surrounding rock under the condition of TM coupled with applying the finite difference FLAC 3D . From this study, thermo-mechanical characteristic of granite is obtained primarily under given canister heat source and given decay law function. And these results show that the reasonable space between disposal hole is 8 m-12 m, and the peak temperature of the canister surface is 130 ℃, the centerline temperature between pits is about 40 ℃ which is maintained for about hundreds of years under given heating output at -500 m depth. (authors)

Aespoe Hard Rock Laboratory Annual Report 2004

International Nuclear Information System (INIS)

2005-08-01

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

Aespoe Hard Rock Laboratory Annual Report 2004

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-08-01

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

Plans for characterization of the potential geologic repository site at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Dobson, D.C.; Blanchard, M.B.; Voegele, M.D.; Younker, J.L.

1990-01-01

Site investigations in the vicinity of the potential repository site at Yucca Mountain, Nevada, have occurred for many years. Although information from previous site investigations was adequate to support preliminary evaluations by the US Department of Energy (DOE) in the Environmental Assessment and to develop conceptual repository and waste package designs, this information is insufficient to proceed to the advanced designs and performance assessments required for the license application to the US Nuclear Regulatory Commission (NRC). Therefore, intensive site characterization is planned, as described in the December 1988 Site Characterization Plan (SCP). The data acquisition activities described in the SCP are focused on obtaining information to allow evaluations of the natural and engineered barriers considered potentially relevant to repository performance. The site data base must be adequate to allow predictions of the range of expected variation in geologic conditions over the next 10,000 years, as well as predictions of the probabilities for catastrophic geologic events that could affect repository performance. 4 refs., 4 figs

Waste-rock interactions in the immediate repository

International Nuclear Information System (INIS)

McCarthy, G.J.

1977-01-01

The high level wastes (HLW's) to be placed underground in rock formations will contain significant amounts of radioactive decay heat for the first hundred-or-so years of isolation. Several physical-chemical changes analogous to natural geochemical processes can occur during this ''thermal period.'' The waste canister can act as a heat source and cause changes in the mineralogy and properties of the surrounding rocks. Geochemically, this is ''contact metamorphism.'' In the event that the canister is corroded and breached, chemical reactions can occur between the HLW, the surrounding rock and possibly the remains of the canister. In a dry repository which has not been backfilled (and thus pressurized) these interactions could be slow at best and with rates decreasing rapidly as the HLW cools. However, significant interactions can occur in years, months or even days under hydrothermal conditions. These conditions could be created by the combination of HLW heat, overburden pressure and water mobilized from the rocks or derived from groundwater intrusion. At the end of the thermal period these interaction products would constitute the actual HLW form (or ''source term'') subject to the low temperature leaching and migration processes under investigation in other laboratories. It is quite possible that these interaction product waste forms will have superior properties compared to the original HLW. Experimental programs initiated at Penn State during the last year aim at determining the nature of any chemical or mineralogical changes in, or interactions between, HLW solids and host rocks under various repository ambients. The accompanying figures describe the simulated HLW forms and the experimental approach and techniques. Studies with basalts as the repository rock are supported by Rockwell Hanford Operations and with shales by the Office of Waste Isolation

Subseabed Disposal Program. Annual report, January-December 1978

International Nuclear Information System (INIS)

Talbert, D.M.

1980-02-01

This is the fifth annual report describing the progress and evaluating the status of the Subseabed Disposal Program (SDP), which was begun in June 1973. The program was initiated by Sandia Laboratories to explore the utility of stable, uniform, and relatively unproductive areas of the world as possible repositories for high-level nuclear wastes. The program, now international in scope, is currently focused on the stable submarine geologic formations under the deep oceans

Assessment of cement durability in repository environment

International Nuclear Information System (INIS)

Ferreira, E.G.A.; Vicente, R.; Isiko, V.L.K.; Miyamoto, H.; Marumo, J.T.; Gobbo, L.A.

2015-01-01

The present research aimed at investigating the durability of cement paste under nuclear waste repository conditions using accelerated tests. Cement paste samples are examined after being exposed to the environmental conditions that are expected to prevail in the repository environment and the results are compared with those obtained with unexposed specimens or specimens exposed to reference conditions. The following exposure conditions were selected: a) Immersion in salt solution, distilled water, or kept in dry storage; b) Room temperature (20 C. degrees) or high temperature (60 C. degrees); c) Immersion time of 30 days or 60 days (not for dry storage); d) Irradiation to a dose of (400 kGy) or background radiation (0 kGy). After exposure to the stressing conditions, the effects of each factor on the cement paste samples were observed by changes in their characteristics. Compressive strength tests were performed on all samples and some of them were investigated in terms of changes in mineralogy by X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). With the results obtained so far it was possible to point out the following conclusions. First, after a period of immersion in water, cement paste samples further hydrated and presented higher mechanical resistance, as expected. Secondly, dry storage did not allow a complete hydration as a consequence of pore water evaporation. High temperatures intensified this process and led to the ettringite decomposition to meta-ettringite. Thirdly, higher temperature accelerated hydration kinetics and promoted higher mechanical resistance in samples kept under immersion. Fourthly, the irradiation dose applied was unable to change the mineralogy of cement paste samples and fifthly, no statistically significant differences were observed between 30 or 60 days exposure time, for the test conditions

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

Materials Degradation Issues in the U.S. High-Level Nuclear Waste Repository

Energy Technology Data Exchange (ETDEWEB)

K.G. Mon; F. Hua

2005-04-12

This paper reviews the state-of-the-art understanding of the degradation processes by the Yucca Mountain Project (YMP) with focus on interaction between the in-drift environmental conditions and long-term materials degradation of waste packages and drip shields within the repository system during the first 10,000-years after repository closure. This paper provides an overview of the degradation of the waste packages and drip shields in the repository after permanent closure of the facility. The degradation modes discussed in this paper include aging and phase instability, dry oxidation, general and localized corrosion, stress corrosion cracking, and hydrogen induced cracking of Alloy 22 and titanium alloys. The effects of microbial activity and radiation on the degradation of Alloy 22 and titanium alloys are also discussed. Further, for titanium alloys, the effects of fluorides, bromides, and galvanic coupling to less noble metals are considered. It is concluded that the materials and design adopted will provide sufficient safety margins for at least 10,000-years after repository closure.

Aerosol particle transport modeling for preclosure safety studies of nuclear waste repositories

International Nuclear Information System (INIS)

Gelbard, F.

1989-01-01

An important concern for preclosure safety analysis of a nuclear waste repository is the potential release to the environment of respirable aerosol particles. Such particles, less than 10 μm in aerodynamic diameter, may have significant adverse health effects if inhaled. To assess the potential health effects of these particles, it is not sufficient to determine the mass fraction of respirable aerosol. The chemical composition of the particles is also of importance since different radionuclides may pose vastly different health hazards. Thus, models are needed to determine under normal and accident conditions the particle size and the chemical composition distributions of aerosol particles as a function of time and of position in the repository. In this work a multicomponent sectional aerosol model is used to determine the aerosol particle size and composition distributions in the repository. A range of aerosol mass releases with varying mean particle sizes and chemical compositions is used to demonstrate the sensitivities and uncertainties of the model. Decontamination factors for some locations in the repository are presented. 8 refs., 1 tab

Materials Degradation Issues in the U.S. High-Level Nuclear Waste Repository

International Nuclear Information System (INIS)

Mon, K.G.; Hua, F.

2005-01-01

This paper reviews the state-of-the-art understanding of the degradation processes by the Yucca Mountain Project (YMP) with focus on interaction between the in-drift environmental conditions and long-term materials degradation of waste packages and drip shields within the repository system during the first 10,000-years after repository closure. This paper provides an overview of the degradation of the waste packages and drip shields in the repository after permanent closure of the facility. The degradation modes discussed in this paper include aging and phase instability, dry oxidation, general and localized corrosion, stress corrosion cracking, and hydrogen induced cracking of Alloy 22 and titanium alloys. The effects of microbial activity and radiation on the degradation of Alloy 22 and titanium alloys are also discussed. Further, for titanium alloys, the effects of fluorides, bromides, and galvanic coupling to less noble metals are considered. It is concluded that the materials and design adopted will provide sufficient safety margins for at least 10,000-years after repository closure

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)

VerSi. A method for the quantitative comparison of repository systems

Energy Technology Data Exchange (ETDEWEB)

Kaempfer, T.U.; Ruebel, A.; Resele, G. [AF-Consult Switzerland Ltd, Baden (Switzerland); Moenig, J. [GRS Braunschweig (Germany)

2015-07-01

Decision making and design processes for radioactive waste repositories are guided by safety goals that need to be achieved. In this context, the comparison of different disposal concepts can provide relevant support to better understand the performance of the repository systems. Such a task requires a method for a traceable comparison that is as objective as possible. We present a versatile method that allows for the comparison of different disposal concepts in potentially different host rocks. The condition for the method to work is that the repository systems are defined to a comparable level including designed repository structures, disposal concepts, and engineered and geological barriers which are all based on site-specific safety requirements. The method is primarily based on quantitative analyses and probabilistic model calculations regarding the long-term safety of the repository systems under consideration. The crucial evaluation criteria for the comparison are statistical key figures of indicators that characterize the radiotoxicity flux out of the so called containment-providing rock zone (einschlusswirksamer Gebirgsbereich). The key figures account for existing uncertainties with respect to the actual site properties, the safety relevant processes, and the potential future impact of external processes on the repository system, i.e., they include scenario-, process-, and parameter-uncertainties. The method (1) leads to an evaluation of the retention and containment capacity of the repository systems and its robustness with respect to existing uncertainties as well as to potential external influences; (2) specifies the procedures for the system analyses and the calculation of the statistical key figures as well as for the comparative interpretation of the key figures; and (3) also gives recommendations and sets benchmarks for the comparative assessment of the repository systems under consideration based on the key figures and additional qualitative

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.

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.

Hydrothermal evolution of repository groundwaters in basalt

International Nuclear Information System (INIS)

Apps, J.A.

1984-01-01

Groundwaters in the near field of a radioactive waste repository in basalt will change their chemical composition in response to reactions with the basalt. These reactions will be promoted by the heat generated by the decaying waste. It is important to predict both the rate and the extent of these reactions, and the secondary minerals produced, because the alteration process controls the chemical environment affecting the corrosion of the canister, the solubility and complexation of migrating radionuclides, the reactivity of the alteration products to radionuclides sorption, and the porosity and permeability of the host rock. A comprehensive review of the literature leads to the preliminary finding that hydrothermally altering basalts in geothermal regions such as Iceland lead to a secondary mineralogy and groundwater composition similar to that expected to surround a repository. Furthermore, laboratory experiments replicating the alteration conditions approximate those observed in the field and expected in a repository. Preliminary estimates were made of the rate of hydration and devitrification of basaltic glass and the zero-order dissolution rate of basaltic materials. The rates were compared with those for rhyolitic glasses and silicate minerals. Preliminary calculations made of mixed process alteration kinetics, involving pore diffusion and surface reaction suggest that at temperatures greater than 150 0 C, alteration proceeds so rapidly as to become pervasive in normally fractured basalt exposed to higher temperatures in the field. 70 references

BMI and BMI SDS in childhood: annual increments and conditional change

OpenAIRE

Brannsether-Ellingsen, Bente; Eide, Geir Egil; Roelants, Mathieu; Bjerknes, Robert; Juliusson, Petur Benedikt

2016-01-01

Background: Early detection of abnormal weight gain in childhood may be important for preventive purposes. It is still debated which annual changes in BMI should warrant attention. Aim: To analyse 1-year increments of Body Mass Index (BMI) and standardised BMI (BMI SDS) in childhood and explore conditional change in BMI SDS as an alternative method to evaluate 1-year changes in BMI. Subjects and methods: The distributions of 1-year increments of BMI (kg/m2) and BMI SDS are summarised by...

Preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt

International Nuclear Information System (INIS)

Taylor, C.L.; O'Rourke, J.E.; Allirot, D.; O'Connor, K.

1980-09-01

This report presents results of a study leading to preconceptual designs for plugging boreholes, shafts, and tunnels to a nuclear waste repository in basalt. Beginning design criteria include a list of preferred plug materials and plugging machines that were selected to suit the environmental conditions, and depths, diameters, and orientations of the accesses to a nuclear waste repository in the Columbia River basalts located in eastern Washington State. The environmental conditions are described. The fiscal year 1979-1980 Task II work is presented in two parts: preliminary testing of materials for plugging of man-made accesses to a repository in basalt (described in a separate report); and preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt (described in this report). To fulfill the scope of the Task II work, Woodward-Clyde Consultants (WCC) was requested to: provide preconceptual systems for plugging boreholes, tunnels, and shafts in basalt; describe preconceptual borehole plugging equipment for placing the selected materials in man-made accesses; utilize the quality assurance program, program plan and schedule, and work plans previously developed for Task II; and prepare a preliminary report

Repository-relevant testing applied to the Yucca Mountain Project

International Nuclear Information System (INIS)

Bates, J.K.; Gerding, T.J.; Veleckis, E.

1989-04-01

A repository environment poses a challenge to developing a testing program because of the diverse nature of conditions that may exist at a given time during the life of the repository. A starting point is to identify whether any potential waste-water contact modes are particularly deleterious to the waste form performance, and whether any interactions between materials present in the waste package environment need to be accounted for during modeling the waste form reaction. The Unsaturated Test method in one approach that has been developed by the Yucca Mountain Project (YMP) to investigate the above issues, and a description of results that have been obtained during the testing of glass and unirradiated UO 2 are the subject of this report. 10 refs., 7 figs., 4 tabs

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

48 CFR 227.7207 - Contractor data repositories.

Science.gov (United States)

2010-10-01

... repositories. 227.7207 Section 227.7207 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS... Computer Software and Computer Software Documentation 227.7207 Contractor data repositories. Follow 227.7108 when it is in the Government's interests to have a data repository include computer software or to...

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.

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

A Careful Blasting Technique During Construction of underground Openings for Nuclear Waste Repository

International Nuclear Information System (INIS)

Ester, Z.; Vrkljan, D.

1998-01-01

Underground nuclear waste repositories are constructed in natural rock formations, with heterogenous compound and structure, and should be accommodated in design and construction according to rock conditions. The quality insurance of underground repository, during and after construction, is most demanding in view of contour and category of excavation. the technology of drilling and blasting, regarding the mechanical excavation, is accommodated in sense of response to cross section magnitude of underground openings, the rock conditions and category, the support performance and other design demands. The high level rock damage around underground openings, that is in opposition with reaching quality insurance. Conventional construction technology can be successful by implementation of controlled blasting technique avoiding extensive rock weakness. (author)

Criticality issues with highly enriched fuels in a repository environment

International Nuclear Information System (INIS)

Taylor, L.L.; Sanchez, L.C.; Rath, J.S.

1998-03-01

This paper presents preliminary analysis of a volcanic tuff repository containing a combination of low enrichment commercial spent nuclear fuels (SNF) and DOE-owned SNF packages. These SNFs were analyzed with respect to their criticality risks. Disposal of SNF packages containing significant fissile mass within a geologic repository must comply with current regulations relative to criticality safety during transportation and handling within operational facilities. However, once the repository is closed, the double contingency credits for criticality safety are subject to unremediable degradation, (e.g., water intrusion, continued presence of neutron absorbers in proximity to fissile material, and fissile material reconfiguration). The work presented in this paper focused on two attributes of criticality in a volcanic tuff repository for near-field and far-field scenarios: (1) scenario conditions necessary to have a criticality, and (2) consequences of a nuclear excursion that are components of risk. All criticality consequences are dependent upon eventual water intrusion into the repository and subsequent breach of the disposal package. Key criticality parameters necessary for a critical assembly are: (1) adequate thermal fissile mass, (2) adequate concentration of fissile material, (3) separation of neutron poison from fissile materials, and (4) sufficient neutron moderation (expressed in units of moderator to fissile atom ratios). Key results from this study indicated that the total energies released during a single excursion are minimal (comparable to those released in previous solution accidents), and the maximum frequency of occurrence is bounded by the saturation and temperature recycle times, thus resulting in small criticality risks

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

SR 97: Post-closure safety for a KBS 3 type deep repository for spent nuclear fuel

International Nuclear Information System (INIS)

Hedin, A.; Kautsky, U.

2000-03-01

Prior to coming site investigations for siting of a deep repository for spent nuclear fuel, SKB has carried out the long-term safety assessment SR 97, requested by the Swedish Government. The repository is of the KBS-3 type, where the fuel is placed in isolating copper canisters with a high-strength cast iron insert. The canisters are surrounded by bentonite clay in individual deposition holes at a depth of 500 m in granitic bedrock. The future evolution of the repository system is analysed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings, including climate, persist. The four other scenarios show the evolution if the repository contains a few initially defective canisters, in the event of climate change, in the event of earthquakes, and in the event of future inadvertent human intrusion. The principal conclusion of the assessment is that the prospects of building a safe deep repository for spent nuclear fuel in Swedish granitic bedrock are very good. (author)

Development of an international safeguards approach to the final disposal of spent fuel in geological repositories

International Nuclear Information System (INIS)

Murphey, W.M.; Moran, B.W.; Fattah, A.

1996-01-01

The International Atomic Energy Agency (IAEA) is currently pursuing development of an international safeguards approach for the final disposal of spent fuel in geological repositories through consultants meetings and through the Program for Development of Safeguards for Final Disposal of Spent Fuel in Geological Repositories (SAGOR). The consultants meetings provide policy guidance to IAEA; SAGOR recommends effective approaches that can be efficiently implemented by IAEA. The SAGOR program, which is a collaboration of eight Member State Support Programs (MSSPs), was initiated in July 1994 and has identified 15 activities in each of three areas (i.e. conditioning facilities, active repositories, and closed repositories) that must be performed to ensure an efficient, yet effective safeguards approach. Two consultants meetings have been held: the first in May 1991 and the last in November 1995. For nuclear materials emplaced in a geological repository, the safeguards objectives were defined to be (1) to detect the diversion of spent fuel, whether concealed or unconcealed, from the repository and (2) to detect undeclared activities of safeguards concern (e.g., tunneling, underground reprocessing, or substitution in containers)

Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

Energy Technology Data Exchange (ETDEWEB)

Gascoyne, M. [Gascoyne GeoProjects Inc, Pinawa, MB (Canada)

1999-04-01

Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O{sub 2}) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O{sub 2} might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O{sub 2} from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O{sub 2} content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O{sub 2} will not penetrate to repository depths over

Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

International Nuclear Information System (INIS)

Gascoyne, M.

1999-04-01

Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O 2 ) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O 2 might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O 2 from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O 2 content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O 2 will not penetrate to repository depths over the next 100,000 years

Peculiarities of the High-Level Concrete-Encased Radwaste Repository Disposition at the Radwaste Disposal Site of the Russian Research Center 'Kurchatov Institute'

International Nuclear Information System (INIS)

Volkov, V.G.; Ponomarev-Stepnoi, N.N.; Gorodetsky, G.G.; Zverkov, Yu.A.; Ivanov, O.P.; Lemus, A.V.; Semenov, S.G.; Stepanov, V.E.; Chesnokov, A.V.; Shisha, A.D.

2006-01-01

The paper presents peculiarities of organization and performance of activities on disposition of the old repository that contained high-level waste and located at the radwaste disposal site of the Russian Research Center 'Kurchatov Institute' in Moscow. The repository was constructed in the late 1950's. A large number of cases with high-level waste were placed in the repository along with low- and intermediate-level waste. When the repository was filled in 1973, the entire radwaste mass was encased in concrete matrix which caused difficulties with the radwaste extraction and made the work on the repository disposition highly hazardous in terms of radiation conditions. Based on results of the preliminary radiation survey of the repository, technologies and equipment to be used in disposition works were selected, and a decision on construction of external radiation shielding around the repository to maintain normal radiation conditions during these works was made. Specific features of the selected radiation shielding design constructed around the repository and of a technology used for the radwaste extraction from the repository are provided. According to the technology, conventional construction machines equipped with a hydraulic hammer or a clamshell were used for destruction of the concrete-encased radwaste mass and extraction of low-level waste. Intermediate- and high-level waste was extracted by remotely controlled robots operating inside the radiation shielding structure. Video cameras and a gamma imager were used for detection of high-level waste or fragments of such radwaste in the mass concrete being destroyed and for guiding remotely controlled robots. Peculiarities of rapid control of changes in radiation conditions in the working areas are presented. This control was performed using a gamma locator with on-line transmission of its data to a PC for their processing. With disposition of this not easily accessible repository, the stage of remediation of old

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

Plugs for deposition tunnels in a deep geologic repository in granitic rock. Concepts and experience

International Nuclear Information System (INIS)

Dixon, D. A.; Boergesson, L.; Gunnarsson, D.; Hansen, J.

2009-11-01

Regardless of the emplacement geometry selected in a geological repository for spent nuclear fuel, there will be a requirement for the access tunnels to remain open while repository operations are ongoing. The period of repository operation will stretch for many years (decades to more than a century depending on disposal concept and number of canisters to be installed). Requirements for extended monitoring of the repository before final closure may further extend the period over which the tunnels must remain open. The intersection of the emplacement rooms/drifts and the access tunnels needs to be physically closed in order to ensure that the canisters remain undisturbed and that no undesirable hydraulic conditions are allowed to develop within the backfilled volume. As a result of these requirements, generic guidelines and design concepts have been developed for 'Plugs' that are intended to provide mechanical restraint, physical security and hydraulic control functions over the short-term (repository operational and pre-closure monitoring periods). This report focuses on the role and requirements of plugs to be installed at emplacement room/ tunnel/drift entrances or in other locations within the repository that may require installation of temporary mechanical or hydraulic control structures. These plugs are not necessarily a permanent feature of the repository and may, if required, be removed for later installation of a permanent seal. Room/Drift plugs are also by their defined function, physically accessible during repository operation so their performance can be monitored and remedial actions taken if necessary (e.g. increased seepage past the plug). A considerable number of sealing demonstrations have been undertaken at several research laboratories that are focussed on development of technologies and materials for use in isolation of spent nuclear fuel and these are briefly reviewed in this report. Additionally, technologies developed for non

Plugs for deposition tunnels in a deep geologic repository in granitic rock. Concepts and experience

Energy Technology Data Exchange (ETDEWEB)

Dixon, D.A. (AECL, Chalk River (Canada)); Boergesson, L. (Clay Technology, Lund (Sweden)); Gunnarsson, D. (Swedish Nuclear Fuel and Waste Management Co, Stockholm (Sweden)); Hansen, J. (Posiva Oy, Eurajoki (Finland))

2009-11-15

Regardless of the emplacement geometry selected in a geological repository for spent nuclear fuel, there will be a requirement for the access tunnels to remain open while repository operations are ongoing. The period of repository operation will stretch for many years (decades to more than a century depending on disposal concept and number of canisters to be installed). Requirements for extended monitoring of the repository before final closure may further extend the period over which the tunnels must remain open. The intersection of the emplacement rooms/drifts and the access tunnels needs to be physically closed in order to ensure that the canisters remain undisturbed and that no undesirable hydraulic conditions are allowed to develop within the backfilled volume. As a result of these requirements, generic guidelines and design concepts have been developed for 'Plugs' that are intended to provide mechanical restraint, physical security and hydraulic control functions over the short-term (repository operational and pre-closure monitoring periods). This report focuses on the role and requirements of plugs to be installed at emplacement room/ tunnel/drift entrances or in other locations within the repository that may require installation of temporary mechanical or hydraulic control structures. These plugs are not necessarily a permanent feature of the repository and may, if required, be removed for later installation of a permanent seal. Room/Drift plugs are also by their defined function, physically accessible during repository operation so their performance can be monitored and remedial actions taken if necessary (e.g. increased seepage past the plug). A considerable number of sealing demonstrations have been undertaken at several research laboratories that are focussed on development of technologies and materials for use in isolation of spent nuclear fuel and these are briefly reviewed in this report. Additionally, technologies developed for non

What do we mean by a cold repository?

International Nuclear Information System (INIS)

Halsey, W.G.

1994-01-01

The topic of thermal loading of a potential repository at Yucca Mountain in Nevada has been the subject of intense discussion within the project technical community. While terms such as ''Hot Repository'' and ''Cold Repository'' are frequently used, they have not been clearly defined. In particular, the definition of a cold repository has remained the opinion of each individual. This has led to confusion and misunderstanding. In this paper, a number of observed definitions for a cold repository are discussed along with the technical implications, assumptions and inconsistencies. Finally, a common language is suggested

Main organic materials in a repository for high level radioactive waste

International Nuclear Information System (INIS)

Hallbeck, Lotta; Grive, Mireia; Gaona, Xavier; Duro, Lara; Bruno, Jordi

2007-11-01

A compilation of the origin and composition of organic material possibly left in a repository is made. Recommendations of precautions and actions for the different material are listed as well. As a brief summary, the different categories of organic material of relevance for the repository are: 1. Microorganisms. Their effect would be mainly a reduction of the redox potential in the initial stages after the repository closure. They may contribute to the depletion of the oxygen entrapped due to the repository construction. This effect would not jeopardize the stability of the repository. If the dominating microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to formation of HS - . The produced sulphide can corrode copper under anaerobic conditions, if it reaches the canisters. Another effect of microorganisms would be the increase of the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the low amounts of the excreted substances. 2. Materials in the ventilation air. Their effect will probably be a contribution to the maintenance of reducing conditions in the area, although it is likely that this effect will be minimal or negligible. 3. Construction materials. Among them we can highlight organic materials present in concrete, asphalt, bentonite and wood. The most important compounds from the repository safety perspective will be those hydrocarbons from asphalt that may contribute to decreasing the redox potential around the repository, and the products of degradation of cellulose. This last category of compounds may contribute to enhance the complexing capacity of the groundwater around the repository and it is recommended to minimize the amount of cellulose left in the repository. 4. Fuels and engine emissions. No important effects from these organics in the repository are expected

Main organic materials in a repository for high level radioactive waste

Energy Technology Data Exchange (ETDEWEB)

Hallbeck, Lotta [Vita vegrandis, Hindaas (Sweden); Grive, Mireia; Gaona, Xavier; Duro, Lara; Bruno, Jordi [Enviros Consulting, Valldoreix, Barcelona (Spain)

2007-11-15

A compilation of the origin and composition of organic material possibly left in a repository is made. Recommendations of precautions and actions for the different material are listed as well. As a brief summary, the different categories of organic material of relevance for the repository are: 1. Microorganisms. Their effect would be mainly a reduction of the redox potential in the initial stages after the repository closure. They may contribute to the depletion of the oxygen entrapped due to the repository construction. This effect would not jeopardize the stability of the repository. If the dominating microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to formation of HS{sup -}. The produced sulphide can corrode copper under anaerobic conditions, if it reaches the canisters. Another effect of microorganisms would be the increase of the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the low amounts of the excreted substances. 2. Materials in the ventilation air. Their effect will probably be a contribution to the maintenance of reducing conditions in the area, although it is likely that this effect will be minimal or negligible. 3. Construction materials. Among them we can highlight organic materials present in concrete, asphalt, bentonite and wood. The most important compounds from the repository safety perspective will be those hydrocarbons from asphalt that may contribute to decreasing the redox potential around the repository, and the products of degradation of cellulose. This last category of compounds may contribute to enhance the complexing capacity of the groundwater around the repository and it is recommended to minimize the amount of cellulose left in the repository. 4. Fuels and engine emissions. No important effects from these organics in the repository are expected

Aespoe Hard Rock Laboratory. Annual report 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

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

An Optimal Centralized Carbon Dioxide Repository for Florida, USA

Directory of Open Access Journals (Sweden)

Brandon Poiencot

2011-03-01

Full Text Available For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida’s electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels, from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s is also presented.

People's perception of LILW repository

International Nuclear Information System (INIS)

Zeleznik, Nadja; Polic, Marko

2002-01-01

our surveys indicated significant differences in answers of experts and lay persons, mainly regarding evaluation of the consequences of repository construction. Although both groups believed that the land in the repository vicinity would lose its value, lay persons emphasized fear of the radioactivity as one of the most important factor, while experts emphasized increased safety due to the constant monitoring. For all of them assurance of safety, and constant informing of the public, were the main conditions of public acceptance of the repository. According to experts' opinion financial compensation could improve the acceptability, while for lay persons it was not so important. Authors believe that the new siting process should assure sufficient information, transparency of actions, and the use of professional but understandable language in communicating with the public, as well as permanent participation of local representatives in the siting process, with the possibility of withdrawing their approval at any stage. The fear of radioactivity should also be taken into consideration, even though it may not have a rational basis. Also it must be borne in mind, that external factors should also be considered, e.g. origin of the waste, high tension between centre and periphery, foreign examples and practices. (author)

Salt Repository Project: Data report on corrosion results obtained from excess-salt corrosion test Matrix 1

International Nuclear Information System (INIS)

Haberman, J.H.; Westerman, R.E.

1987-05-01

The test discussed in this data report was directed at determining the response of the reference A216 grade WCA steel when it is exposed to anoxic excess-salt conditions at 150 0 C. The environment used in the test was intended to duplicate the intrusion brine scenario (i.e., the formation of brine by the intrusion of water from an outside source into the repository, with the formation of brine through dissolution of salt from the repository horizon). The salt-brine environment used in the test therefore reflected the expected gross salt composition of the repository horizon

Long Term Behaviour of 14C and Stability Assessments of Graphite Under Repository Conditions

International Nuclear Information System (INIS)

Jones, Abbie N.; McDermott, Lorraine; Worth, Robert; Hagos, Bereket; Black, Greg; Marsden, Barry J

2016-01-01

The key objectives of the University of Manchester’s nuclear graphite research within the CRP are to provide analysis on the long term behaviour and stability assessments of irradiated graphite waste. The research will concentrate on isotopic 14 C mobility under repository environments. This also requires an understanding the long-term behaviour of the final waste form under repository conditions. Procedures to evaluate the long term leaching properties of radionuclides from irradiated graphite waste has been developed by combining ANSI 16.1 (USA) and NEN 7345 (Netherlands) standardised diffusion leaching techniques. The ANSI 16.1 standard has been followed to acquire the leachates and to determine the leach rate and diffusion coefficient. The NEN 7345 standard technique has been used to determine the diffusion mechanism of radionuclides. The investigation employs simulated Drigg groundwater as a leachant using semi-dynamic technique for the production of leachate specimens. Analysis of 3 H and 14 C activity release from Magnox graphite was measured using liquid scintillating counting. Preliminary results show that there is an initial high release of activity and decreases when the leaching period increases. This may be due to the depletion of contaminants that were initially bound by the internal pore networks and the free surface. During the leaching test approximately 275.33 ± 18.20 Bq of 3 H and 106.26 ± 7.01 Bq of 14 C was released into the leachant within 91 days. The work reported herein contributed several key findings to the international work on graphite leaching to offer guidance leading toward obtaining leaching data in the future: (a) the effective diffusion coefficient for 14 C from graphite waste has been determined. The diffusion process for 14 C has two stages resulting two different values of diffusion coefficient, i.e., for the fast and slow components; (b) the controlling leaching mechanism for 3 H radionuclide from graphite is shown to be

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)

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)

Development of a central final repository management for the coordination of the waste for Schacht Konrad from public authorities; Aufbau des zentralen Endlagerungsmanagements fuer die Koordination der Konrad-Abfaelle aus der oeffentlichen Hand

Energy Technology Data Exchange (ETDEWEB)

Graffunder, Iris; Dominke-Bendix, Carola; Waldek, Achim [Energiewerke Nord GmbH (EWN), Eggenstein-Leopoldshafen (Germany). Betriebsstaette Karlsruhe; Wunn, Christoph [admoVa Consulting GmbH, Bad Camberg (Germany)

2012-11-01

The central final repository management is supposed to fulfill the following tasks: active collaboration of Konrad contract draft, signing of internal contracts and agreements, cooperation contract with GNS, cooperation with coordination authorities, inventory taking of wastes (existing inventory and prognosis) and interim storage capacities of public authorities, development of planning and management software, optimization of the final repository documentation, container management, logistics concept, long-term disposal planning and prognosis, planning and coordination of the annual waste amount, management and documentation of disposed waste allocation, coordination of transport schedules, consulting service for waste obligations (final repository requirements, product control, documentation).

Global thermo-mechanical effects from a KBS-3 type repository. Summary report

International Nuclear Information System (INIS)

Hakami, E.; Olofsson, Stig-Olof; Hakami, H.; Israelsson, Jan

1998-04-01

The objective of this study has been to identify the global thermomechanical effects in the bedrock hosting a nuclear waste repository - i.e. the effects at large distances from the repository. Numerical thermomechanical modeling was performed in several steps, beginning with elastic continuum models and followed by distinct element models (3DEC), in which fracture zones are explicitly simulated. The number of fracture zones, the heat intensity of the waste, the material properties of the rock mass and the boundary conditions of the models were varied in different simulations. The results from the numerical modeling show that the principal stresses increase near the repository. The maximum stress obtained for the main model is 44 MPa and occurs at the repository level after about 100 years of deposition. Due to thermal expansion, the rock mass displaces upward, and the maximum heave at the ground surface after 1000 years is calculated to be 16 cm. In the area close to the ground surface, above the center of the repository, the horizontal stresses reduce, causing the rock to yield in tension down to a depth of about 80 m. In correspondence with the stress changes, the fracture zones show opening normal displacements at shallow depths and closing normal displacements and shearing at the repository level. The maximum displacements of the different fracture zones are 0.3-2.5 cm for closing, 0.0-0.8 cm for opening and 0.2-2.2 cm for shearing. Another important input parameter for the analysis is the Young's modulus of the rock mass. In the main model, a value of 30 GPa is assumed. Higher values of Young's modulus give larger thermo-mechanical effects. Other changes of the properties considered give minor changes of the rock mass behavior. All multi-level repository layouts give rise to higher temperatures than the single-level layout, causing the compressive stresses to increase more at the repository level. Fracture zone displacements caused by different layouts are

NRC high-level radioactive waste program. Annual progress report: Fiscal Year 1996

International Nuclear Information System (INIS)

Sagar, B.

1997-01-01

This annual status report for fiscal year 1996 documents technical work performed on ten key technical issues (KTI) that are most important to performance of the proposed geologic repository at Yucca Mountain. This report has been prepared jointly by the staff of the Nuclear Regulatory Commission (NRC) Division of Waste Management and the Center for Nuclear Waste Regulatory Analyses. The programmatic aspects of restructuring the NRC repository program in terms of KTIs is discussed and a brief summary of work accomplished is provided. The other ten chapters provide a comprehensive summary of the work in each KTI. Discussions on probability of future volcanic activity and its consequences, impacts of structural deformation and seismicity, the nature of of the near-field environment and its effects on container life and source term, flow and transport including effects of thermal loading, aspects of repository design, estimates of system performance, and activities related to the U.S. Environmental Protection Agency standard are provided

Rainfall and net infiltration probabilities for future climate conditions at Yucca Mountain

International Nuclear Information System (INIS)

Long, A.; Childs, S.W.

1993-01-01

Performance assessment of repository integrity is a task rendered difficult because it requires predicting the future. This challenge has occupied many scientists who realize that the best assessments are required to maximize the probability of successful repository sitting and design. As part of a performance assessment effort directed by the EPRI, the authors have used probabilistic methods to assess the magnitude and timing of net infiltration at Yucca Mountain. A mathematical model for net infiltration previously published incorporated a probabilistic treatment of climate, surface hydrologic processes and a mathematical model of the infiltration process. In this paper, we present the details of the climatological analysis. The precipitation model is event-based, simulating characteristics of modern rainfall near Yucca Mountain, then extending the model to most likely values for different degrees of pluvial climates. Next the precipitation event model is fed into a process-based infiltration model that considers spatial variability in parameters relevant to net infiltration of Yucca Mountain. The model predicts that average annual net infiltration at Yucca Mountain will range from a mean of about 1 mm under present climatic conditions to a mean of at least 2.4 mm under full glacial (pluvial) conditions. Considerable variations about these means are expected to occur from year-to-year

Analytical model for screening potential CO2 repositories

Science.gov (United States)

Okwen, R.T.; Stewart, M.T.; Cunningham, J.A.

2011-01-01

Assessing potential repositories for geologic sequestration of carbon dioxide using numerical models can be complicated, costly, and time-consuming, especially when faced with the challenge of selecting a repository from a multitude of potential repositories. This paper presents a set of simple analytical equations (model), based on the work of previous researchers, that could be used to evaluate the suitability of candidate repositories for subsurface sequestration of carbon dioxide. We considered the injection of carbon dioxide at a constant rate into a confined saline aquifer via a fully perforated vertical injection well. The validity of the analytical model was assessed via comparison with the TOUGH2 numerical model. The metrics used in comparing the two models include (1) spatial variations in formation pressure and (2) vertically integrated brine saturation profile. The analytical model and TOUGH2 show excellent agreement in their results when similar input conditions and assumptions are applied in both. The analytical model neglects capillary pressure and the pressure dependence of fluid properties. However, simulations in TOUGH2 indicate that little error is introduced by these simplifications. Sensitivity studies indicate that the agreement between the analytical model and TOUGH2 depends strongly on (1) the residual brine saturation, (2) the difference in density between carbon dioxide and resident brine (buoyancy), and (3) the relationship between relative permeability and brine saturation. The results achieved suggest that the analytical model is valid when the relationship between relative permeability and brine saturation is linear or quasi-linear and when the irreducible saturation of brine is zero or very small. ?? 2011 Springer Science+Business Media B.V.

Natural geochemical analogues of the near field of high-level nuclear waste repositories

International Nuclear Information System (INIS)

Apps, J.A.

1995-01-01

United States practice has been to design high-level nuclear waste (HLW) geological repositories with waste densities sufficiently high that repository temperatures surrounding the waste will exceed 100 degrees C and could reach 250 degrees C. Basalt and devitrified vitroclastic tuff are among the host rocks considered for waste emplacement. Near-field repository thermal behavior and chemical alteration in such rocks is expected to be similar to that observed in many geothermal systems. Therefore, the predictive modeling required for performance assessment studies of the near field could be validated and calibrated using geothermal systems as natural analogues. Examples are given which demonstrate the need for refinement of the thermodynamic databases used in geochemical modeling of near-field natural analogues and the extent to which present models can predict conditions in geothermal fields

Evaluation of backfill materials for a shallow-depth repository

International Nuclear Information System (INIS)

Buckley, L.P.; Arbique, G.M.; Tosello, N.B.; Woods, B.L.

1986-11-01

The focus of laboratory research effort on the disposal of low- and intermediate-level radioactive waste is to determine what conditions will dominate and which engineered barriers will be most effective for the retention of radionuclides. Initial studies have concentrated on the evaluation of a flooded repository and the assessment of backfill materials suitable for the adsorption of radioactivity, yet permeable enough to allow excess water to pass through the repository and into the underlying water table. Both physical and adsorption studies have been performed. Based on these preliminary experiments, it is felt that a mixture of 10 wt% clay and the remainder sand would satisfy the above criteria. Since both are available within the Ottawa Valley, they also have the added advantage of being more cost effective to use than imported materials

Salt Repository Project input to seismic design: Revision 0

International Nuclear Information System (INIS)

1987-12-01

The Salt Repository Program (SRP) Input to Seismic Design (ISD) documents the assumptions, rationale, approaches, judgments, and analyses that support the development of seismic-specific data and information to be used for shaft design in accordance with the SRP Shaft Design Guide (SDG). The contents of this document are divided into four subject areas: (1) seismic assessment, (2) stratigraphy and material properties for seismic design, (3) development of seismic design parameters, and (4) host media stability. These four subject areas have been developed considering expected conditions at a proposed site in Deaf Smith County, Texas. The ISD should be used only in conjunction with seismic design of the exploratory and repository shafts. Seismic design considerations relating to surface facilities are not addressed in this document. 54 refs., 55 figs., 18 tabs

Technical, institutional and economic factors important for developing a multinational radioactive waste repository

International Nuclear Information System (INIS)

1998-06-01

Countries planning and implementing nuclear energy programmes should assume responsibility for the safe management and final disposal of radioactive waste from their programmes. However, there are countries whose radioactive waste volumes do not easily justify a national repository, and/or countries which do not have the resources or favorable natural conditions for waste disposal to dedicate to a national repository project. These countries would benefit from multinational co-operation for the disposal. Interest in the concept of a multinational repository for radioactive waste has been expressed by several Member States and the waste management community in the light of the potential benefit to the partner countries from the safety, technical and economic standpoints. However, such an approach involves many political and public acceptance issues and therefore a consensus among countries or regions concerned is a prerequisite. In this context, it was deemed appropriate that the IAEA access the technical, institutional, ethical and economic factors to be taken into account in the process of such consensus building. This report is intended to provide an assessment which can serve as a general basis for establishing a waste management policy and/or further assessing specific issues such as ownership and liability, institutional aspects and problems related to long term commitments. This report is divided into five sections where the first section gives background, objectives, scope and structure of the report. Section 2 discusses multinational repository concept in terms of needs and the role of a multinational repository, interaction between host and partner countries and formulation of a multinational repository. Section 3 identifies basic issues to be considered for establishing a multinational repository, and some specific issues relating to specific waste categories. Section 4 analyses potential benefits and challenges to be addresses in establishing a

Memory provisions for the Manche Surface Repository

International Nuclear Information System (INIS)

Dumont, Jean-Noel; Espiet-Subert, Florence

2015-01-01

The French La Manche repository site received its last radioactive waste package in 1994. In 2003, the official surveillance phase of the closed repository started under the supervision of Andra (the national industrial operator), the French Nuclear Safety Authority (ASN) and society (e.g. the local municipalities). Florence Espiet explained that information on the existence of the repository, its content, how it was operated and how it works needs to be preserved. It also is planned to review the information periodically for a minimum of 300 years. She described the creation of two documents on memory (a detailed and a summary one), both on permanent paper, and the preservation of the land registration. The latter constitutes 'passive' provisions for preserving memory. In addition, a number of 'active' provisions are and will be put in place: guided visits, exhibitions, partnerships with organisations dealing with memory preservation, and the creation of a think tank. The latter consists of local citizens and politicians, retired employees from Andra and artists that meet several times a year and reflect on memory preservation from the perspective of, for instance, local history, education, arts and rituals. Finally, two types of markers will be used to preserve the repository's memory: i) three herbaria cataloguing the plants growing on the site of the repository, including a very short description of the repository, will be stored at different sites in France; ii) a stele indicating the main characteristics of the repository, potentially linked to an art work, will be erected at the repository

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

How many geologic repositories will be needed

International Nuclear Information System (INIS)

Evans, T.J.; Halstead, R.J.

1987-01-01

DOE's postponement of site-specific work on the second repository program had rekindled debate over the number of geologic repositories needed for disposal of high level radioactive waste. The multiple repository approach grew out of the March, 1979 IRG report, which recommended co-disposal of civilian and defense HLW in a system of regional repositories. The multiple repository approach was adopted by DOE, and incorporated in the Nuclear Waste Policy Act passed by Congress in December, 1982. Since the late 1970's, the slower than anticipated growth of the nuclear power industry has substantially reduced earlier estimates of the amount of civilian spent fuel which will require geologic disposal. Reactors currently in operation (78.5 GWe) and reactors in the construction pipeline (28 GWe) are expected to discharge about 103,200 MTU of spent fuel by the year 2036, assuming no increase in fuel burnup rate. By the year 2020, defense high level radioactive wastes equivalent to as much as 27,000 MTU could require geologic disposal. Small amounts of high level waste from other sources will also require geologic disposal. Total disposal requirements appear to be less than 140,000 MTU. The five sites nominated for the first repository, as well as hypothetical sites in granite, the host rock under primary consideration for the second repository, all appear capable of accommodating up to 140,000 MTU

Formulating a low-alkalinity cement for radioactive waste repositories

Energy Technology Data Exchange (ETDEWEB)

Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X

2004-07-01

A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

Formulating a low-alkalinity cement for radioactive waste repositories

International Nuclear Information System (INIS)

Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X.

2004-01-01

A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

Effects on surface hydrology and near-surface hydrogeology of an open repository in Laxemar Results of modelling with MIKE SHE

International Nuclear Information System (INIS)

Maartensson, Erik; Gustafsson, Lars-Goeran; Bosson, Emma

2009-10-01

This report presents the methodology and the results from the modelling of an open repository for spent nuclear fuel in Laxemar. Specifically, the present work analyses the hydrological effects of the planned repository during the construction and operational phases when it is open, i.e. air-filled, and hence may cause a disturbance of the hydrological conditions in the surroundings. The numerical modelling is based on the SDM-Site Laxemar MIKE SHE model. The modelling was divided into three steps. The first step was to update the SDM-Site Laxemar model with a new hydrogeological bedrock model. The other main updates were an increase of the depth of the MIKE SHE model domain, enhanced vertical computational resolution and that the drainage of the Aespoe Hard Rock Laboratory was included in the model. The resulting model was used to simulate undisturbed natural conditions. The next step was to describe the open repository conditions, using Laxemar layout D2, by implementing the access tunnel, the repository tunnels and shafts in the model, and to simulate the consequences for the surface hydrology caused by an open repository under different conditions. The final step was a sensitivity analysis that aimed to investigate the sensitivity of the modelled effects of the open repository to the hydrogeological properties of the bedrock and the Quaternary deposits, the sediments under the sea, and changes in boundary conditions. The model covers an area of 34 km 2 . The groundwater divides were assumed to coincide with the surface water divides; thus, a no-flow boundary condition was used at the horizontal boundaries, except in the Quaternary deposit layers towards the sea where a time-varying boundary condition describing the sea-level in the area was used. In the bedrock layers, however, a no-flow boundary condition was applied. Also the bottom boundary was described as a no-flow boundary. The transient top boundary condition was based on meteorological data gathered at

Low and medium level radioactive waste repository: risk perception

International Nuclear Information System (INIS)

Aquino, Afonso Rodrigues de; Bueno, Lilian de Oliveira; Vieira, Martha Marques Ferreira; Fonseca, Edvaldo Roberto Paiva da; Bellintani, Sandra Aparecida

2009-01-01

This paper focuses on the risk perception associated to the installation of low and intermediate level radioactive waste (LLRW and ILRW) disposal facilities. The purpose is to give support for the implementation of a repository in Brazil. Public acceptance results from a long term work and trust is vital for the process as it takes long to be conquered but might be shortly lost. Therefore, it is essential to care about the way each step is conducted. The knowledge about the system and the risks, the comprehension about these risks, the commitment with safety, adequate support systems for the project (legislation, involved institutions) and the excellence as a goal to be reached are extremely important parameters. The involvement of all interested parties in the decision-making process is condition for a successful and publicly acceptable implementation of such project. The steps for public acceptance of a repository are summarized as follow: Risk perception: to verify how the local population understand and feel the installation of a repository in the region. Media observatory: to continuously follow the news reaching the region where the repository will be installed, including different media. Local population social/economical/cultural profile identification: to determine the local population social/economical/cultural profile; to conduct a survey to know their expectations, allowing the proposal of compensation and incentives to fully account for their expectations. Finally, the philosophy governing this Project is: on doubt, the public must be heard and only after this public hearing the policies concerning the project shall be formulated. (author)

Low and medium level radioactive waste repository: risk perception

Energy Technology Data Exchange (ETDEWEB)

Aquino, Afonso Rodrigues de; Bueno, Lilian de Oliveira; Vieira, Martha Marques Ferreira; Fonseca, Edvaldo Roberto Paiva da; Bellintani, Sandra Aparecida [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: araquino@ipen.br, e-mail: lbueno@ipen.br, e-mail: mmvieira@ipen.br, e-mail: efonseca@ipen.br, e-mail: sbellint@ipen.br

2009-07-01

This paper focuses on the risk perception associated to the installation of low and intermediate level radioactive waste (LLRW and ILRW) disposal facilities. The purpose is to give support for the implementation of a repository in Brazil. Public acceptance results from a long term work and trust is vital for the process as it takes long to be conquered but might be shortly lost. Therefore, it is essential to care about the way each step is conducted. The knowledge about the system and the risks, the comprehension about these risks, the commitment with safety, adequate support systems for the project (legislation, involved institutions) and the excellence as a goal to be reached are extremely important parameters. The involvement of all interested parties in the decision-making process is condition for a successful and publicly acceptable implementation of such project. The steps for public acceptance of a repository are summarized as follow: Risk perception: to verify how the local population understand and feel the installation of a repository in the region. Media observatory: to continuously follow the news reaching the region where the repository will be installed, including different media. Local population social/economical/cultural profile identification: to determine the local population social/economical/cultural profile; to conduct a survey to know their expectations, allowing the proposal of compensation and incentives to fully account for their expectations. Finally, the philosophy governing this Project is: on doubt, the public must be heard and only after this public hearing the policies concerning the project shall be formulated. (author)

New wireless data transmission system based on high frequency radio communication: design, development and testing results under repository conditions

International Nuclear Information System (INIS)

Garcia-Sineriz, J.L.; Barcena, I.; Espada, F.; Rodriguez, A.; Mayor, J.C.; Barnichon, J.D.; Dick, P.

2012-01-01

Document available in extended abstract form only. According to the starting basis of the MoDeRn project (FP7 232598), the design and development of a system capable of transmitting the evolution of the physical parameters inside a repository will be a challenging task due to the harsh working conditions imposed by both the element itself to be monitored (for instance the canister enclosing radioactive waste), the engineered barriers into which they will be embedded and the host rock that contains everything. The measuring devices will work exposed to high pressures, high temperatures, high humidity degrees, presence of radiation, etc., during an expected lifetime of several decades without any possibility of either being powered from any external source or being replaced in case of malfunction, as the operating area will be sealed and inaccessible. Therefore, a main objective of AITEMIN and ENRESA contribution to MoDeRn was focused on the design, development and test under 'real conditions' of a new wireless system, based on high frequency radio transmission (HF), capable of monitoring the physical parameters inside a repository cell independently of the host rock type. In order to achieve the aforementioned objectives and to obtain a suitable monitoring system for the target application, the following key points have been addressed: 1. Data transmission technology (transmission media); 2. Communication protocols; 3. Available power sources; 4. Expected environmental conditions; 5. Suitable sensors. The activities carried out for the development of the HF wireless system were structured in three steps: 1. Laboratory work, to select the best solutions under controlled environment. 2. Field testing, to validate under more realistic conditions the solutions selected at lab. 3. Demonstration: long-term evaluation of the real performance of the solutions proved to be applicable during the field testing Obtained results were as follows: 1. A suitable radio communication

Building Scientific Data's list of recommended data repositories

Science.gov (United States)

Hufton, A. L.; Khodiyar, V.; Hrynaszkiewicz, I.

2016-12-01

When Scientific Data launched in 2014 we provided our authors with a list of recommended data repositories to help them identify data hosting options that were likely to meet the journal's requirements. This list has grown in size and scope, and is now a central resource for authors across the Nature-titled journals. It has also been used in the development of data deposition policies and recommended repository lists across Springer Nature and at other publishers. Each new addition to the list is assessed according to a series of criteria that emphasize the stability of the resource, its commitment to principles of open science and its implementation of relevant community standards and reporting guidelines. A preference is expressed for repositories that issue digital object identifiers (DOIs) through the DataCite system and that share data under the Creative Commons CC0 waiver. Scientific Data currently lists fourteen repositories that focus on specific areas within the Earth and environmental sciences, as well as the broad scope repositories, Dryad and figshare. Readers can browse and filter datasets published at the journal by the host repository using ISA-explorer, a demo tool built by the ISA-tools team at Oxford University1. We believe that well-maintained lists like this one help publishers build a network of trust with community data repositories and provide an important complement to more comprehensive data repository indices and more formal certification efforts. In parallel, Scientific Data has also improved its policies to better support submissions from authors using institutional and project-specific repositories, without requiring each to apply for listing individually. Online resources Journal homepage: http://www.nature.com/scientificdata Data repository criteria: http://www.nature.com/sdata/policies/data-policies#repo-criteria Recommended data repositories: http://www.nature.com/sdata/policies/repositories Archived copies of the list: https

Calculation of fluxes through a repository caused by a local well

International Nuclear Information System (INIS)

Thunvik, R.

1983-05-01

The purpose of the present study is to roughly estimate the ground water flux through a radioactive repository in relation to the flux into a local well under various conditions. The well is assumed to be located at a depth of either 60 or 200 metres below the ground surface. Two main settings are considered, in one the well is located in a vertical fracture zone at a distance of 100 metres from one of the outer edges of the repository. The withdrawal from the well is assumed to be 6 m 3 /day. The flow domain is characterized by a rather low permeability. The boundary conditions considered are either a continuously saturated upper boundary and impervious lateral boundaries, or a phreatic upper boundary and hydrostatic lateral boundaries. The ratio of the flux through the repository to the flux into the well was obtained to be in the range from about 10- 5 to 10- 3 , depending on the boundary conditions and the depth of the well. The lowest figures were obtained in the examples, in which the upper boundary was assumed to be continually saturated. It is concluded that these examples may be considered representative of the actual flow problem. This conclusion is based upon the fact that in the case of a phreatic boundary the drawdown caused by the well was very small and the flow responses were very slow, implying that rather a small infiltration rate is requied to maintain saturated conditions at the upper boundary. The regional gradients caused by the well were rather small in comparison with the typically naturally occurring gradients. The flow to the well will therefore have little influence on the regional flow pattern in most practical cases. (author)

Long term behaviour of low and intermediate level waste packages under repository conditions. Results of a co-ordinated research project 1997-2002

International Nuclear Information System (INIS)

2004-06-01

The development and application of approaches and technologies that provide long term safety is an essential issue in the disposal of radioactive waste. For low and intermediate level radioactive waste, engineered barriers play an important role in the overall safety and performance of near surface repositories. Thus, developing a strong technical basis for understanding the behaviour and performance of engineered barriers is an important consideration in the development and establishment of near surface repositories for radioactive waste. In 1993, a Co-ordinated Research Project (CRP) on Performance of Engineered Barrier Materials in Near Surface Disposal Facilities for Radioactive Waste was initiated by the IAEA with the twin goals of addressing some of the gaps in the database on radionuclide isolation and long term performance of a wide variety of materials and components that constitute the engineered barriers system (IAEA-TECDOC-1255 (2001)). However, during the course of the CRP, it was realized that that the scope of the CRP did not include studies of the behaviour of waste packages over time. Given that a waste package represents an important component of the overall near surface disposal system and the fact that many Member States have active R and D programmes related to waste package testing and evaluation, a new CRP was launched, in 1997, on Long Term Behaviour of Low and Intermediate Level Waste Packages Under Repository Conditions. The CRP was intended to promote research activities on the subject area in Member States, share information on the topic among the participating countries, and contribute to advancing technologies for near surface disposal of radioactive waste. Thus, this CRP complements the afore mentioned CRP on studies of engineered barriers. With the active participation and valuable contributions from twenty scientists and engineers from Argentina, Canada, Czech Republic, Egypt, Finland, India, Republic of Korea, Norway, Romania

Eighth annual occupational radiation exposure report, 1975

International Nuclear Information System (INIS)

Brooks, B.G.

1976-10-01

This is a report by the U.S. Nuclear Regulatory Commission on the operation of the Commission's centralized repository of personnel occupational radiation exposure information. Annual reports were received from 387 covered licensees indicating that some 78,713 individuals, having an average exposure of 0.36 rems, were monitored for exposure to radiation during 1975 and that 21,601 individuals terminated their employment or work assignment with covered licensees in 1975. The number of personnel overexposures reported in 1975 decreased from previous years. The most significant overexposures which occurred in 1975 are summarized

Annual Technology Baseline (Including Supporting Data); NREL (National Renewable Energy Laboratory)

Energy Technology Data Exchange (ETDEWEB)

Blair, Nate; Cory, Karlynn; Hand, Maureen; Parkhill, Linda; Speer, Bethany; Stehly, Tyler; Feldman, David; Lantz, Eric; Augusting, Chad; Turchi, Craig; O' Connor, Patrick

2015-07-08

Consistent cost and performance data for various electricity generation technologies can be difficult to find and may change frequently for certain technologies. With the Annual Technology Baseline (ATB), National Renewable Energy Laboratory provides an organized and centralized dataset that was reviewed by internal and external experts. It uses the best information from the Department of Energy laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information. The ATB includes both a presentation with notes (PDF) and an associated Excel Workbook. The ATB includes the following electricity generation technologies: land-based wind; offshore wind; utility-scale solar PV; concentrating solar power; geothermal power; hydropower plants (upgrades to existing facilities, powering non-powered dams, and new stream-reach development); conventional coal; coal with carbon capture and sequestration; integrated gasification combined cycle coal; natural gas combustion turbines; natural gas combined cycle; conventional biopower. Nuclear laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information.

The importance of the retrievability of nuclear waste for the implementation of safeguard regimes for geologic repositories

International Nuclear Information System (INIS)

Swahn, J.A.

1999-01-01

To find acceptance for the construction and siting of spent fuel repositories retrievability of the spent fuel is a desired feature. In order to minimize the levels of safeguards needed for the plutonium in spent fuel repositories the retrievability should be as low as possible. These contradictory goals have be balanced against each other during the operational phase, before closure and after closure of the repository. Arguments can be made for having the spent fuel in a highly-retrievable state during the operational phase, in a semi-retrievable state at the end of the operational phase but before closure and in a low-retrievable state after closure. The spent fuel in a mined geologic repository will never be able to be considered irretrievable and surveillance of the repository will be needed for an extended time after closure. The level of safeguards needed will depend on the local, regional and global societal conditions for several hundred thousand years into the future. (author)

The industrial organization of the repository. Pitfall or logical?; Slutfoervarets industriella organisering. Fallgrop eller foeljdriktighet?

Energy Technology Data Exchange (ETDEWEB)

Frostenson, Magnus (Dept. of Business Studies, Uppsala Univ., Uppsala (Sweden))

2010-11-15

From a systems perspective the organization of the Swedish final repository project for nuclear waste is studied. Different aspects of organization are identified in the report, covering dimensions of geographical, operative, structural, responsibility and contextual organization. Following SKB's site selection for the applications for the final repository for spent nuclear system and the closing of the surplus value agreement, issues concerning operative, structural and contextual organization tend to become particularly pressing, which is reflected in three research questions: - How will the final repository project be organized operatively and structurally over time? - Why is the final repository project organized in this way by SKB? - What kind of contextual organization takes place in the final repository project and what are the consequences of these activities? How the different industrial units of the final repository project should be run and within which structure, for example concerning ownership and integration of units, is established in the report. SKB's reasons for choosing this kind of organization are also highlighted. Apart from legal and safety-related demands that must be met together with the demands of the owners, SKB's strategic preference for insourcing conditions organizational choices. The traditional task centred operative and structural organization of SKB is also reflected in the organizational choices for the present and future units of the final depository system. Contextual organization implies deepened actor relationships between SKB's owners and SKB on the one side and the municipalities Oesthammar and Oskarshamn on the other. Through active organizing, the final repository arena 'narrows down' and the final repository issue turns into an in many respects local issue. There is a clear tendency that the roles of SKB are multiplied in order to handle the demands that central stakeholders - in particular

Draft environmental assessment: reference repository location, Hanford Site, Washington. Nuclear Waste Policy Act (Section 112)

International Nuclear Information System (INIS)

1984-12-01

In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the reference repository location at the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received on the draft EA. The reference repository location at Hanford is located in the Columbia Plateau, one of five distinct geohydrologic settings that are being considered for the first repository. On the basis of the evaluations reported in this draft EA, the DOE has found that the reference repository location at Hanford is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is proposing to nominate the reference repository location at Hanford as one of five sites suitable for characterization. Furthermore, having performed a comparative evaluation of the five sites proposed for nomination, the DOE has determined that the reference repository location at Hanford is one of three sites preferred for site characterization

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...

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)

Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

International Nuclear Information System (INIS)

R.B. Rebak

2006-01-01

Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking

Literature survey on solid and aqueous species of importance for nuclear waste repositories: The elements uranium, neptunium and cesium

International Nuclear Information System (INIS)

Bucher, J.J.

1987-01-01

This document contains extensive tables listing all possible chemical compounds of species that might occur in a proposed nuclear waste repository. Most are listed as unlikely to occur under conditions predicted for the repository. Extensive data tables and reference sources are provided for those compounds that might occur on form

Numerical modeling of magma-repository interactions

NARCIS (Netherlands)

Bokhove, Onno

2001-01-01

This report explains the numerical programs behind a comprehensive modeling effort of magma-repository interactions. Magma-repository interactions occur when a magma dike with high-volatile content magma ascends through surrounding rock and encounters a tunnel or drift filled with either a magmatic

Multinational/regional repository - an illusion or solution

International Nuclear Information System (INIS)

Mele, I.

2006-01-01

The concept and current status of multinational and regional repositories are presented in the paper. Particular emphasis is given to the results and findings of the recent EU project SAPIERR, investigating the feasibility of regional repository concepts in Europe. Prospects for further development of multinational repositories are also brought forward and the impact and potential benefits of this approach to our national disposal programme are discussed as well. (author)

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

New system for the container conditioning of liquid waste in the German future finale repository 'Schacht Konrad'

International Nuclear Information System (INIS)

Starke, H.

2012-01-01

The full text of publication follows. On-site the NPP Gundremmingen liquid radioactive waste from the NPP water treatment plant is stored in resin or concentrate collecting tanks. These liquid wastes are cemented in containers in order to temporarily store them in the Bavarian interim storage Mitterteich until they are transported into final repository in 'Schacht Konrad'. With this new system liquid radioactive waste is for the first time conditioned directly into containers destined for final repository in 'Schacht Konrad'. Thus, a very secure and sustainable procedure was developed which also provides high profitability. The conditioning plant for resins and concentrate extracts the liquid waste from the respective collecting tank and transports the waste to the separation tank. This separation tank is dimensioned to ensure complete filling of a Konrad container with only one batch. Within the tank there is the option to adjust the suspensions solids content by either extracting supernatant water or by adding de-ionised water. The specific activity is analysed and after the radiologic data and the solids content are available, the containers are cemented. The required amount of cement is based on the solids content and is automatically added. In the mixer, cement and primary waste suspension are mixed. This mixture is filled into the Konrad container via the allocator. The allocator is a funnel-shaped inlet equipped with a movable tube which makes sure the mixture is evenly spread and also ensures optimal filling of the Konrad container. While filling is ongoing, the container is covered by a lowerable splash guard to avoid contamination. The room situation in Gundremmingen and the specific activities of the primary waste suspension make it necessary to disperse the plant to several rooms. Main components such as separation tanks and pumps are installed in shielded rooms. All activities are conducted remotely controlled and are supervised from the central

Current status of geotechnical research on the long-term safety of permanent repositories for nuclear waste

International Nuclear Information System (INIS)

Langer, M.

1988-01-01

The planned permanent underground repository for non-heat-generating wastes in the former Konrad iron-ore mine is now in the final stages of the plan approval procedures. The deadline for the final stages of the plan approval procedures for the Gorleben salt dome is approaching. It is time to give an account of what has been accomplished in the geotechnical field. The BGR has developed a complex geotechnical stability analysis that takes into account the requirements of permanent storage and the objectives required for the protection of the biosphere. This stability analysis is based on the following considerations: Owing to the complexity of the boundary conditions, a cavity intended for a permanent repository can be demonstrated to be safe only by a combination of studies and simulations. These studies must integrate engineering geology, geotechnics, rock mechanics, statics, monitoring of the conditions in the repository, and mining expertise. (orig.) With 27 figs

The Lincoln Repository presentation: ten reasons why you should put a copy of your work in the Repository

OpenAIRE

Stainthorp, Paul

2010-01-01

Slideshow presentation created to promote the Lincoln Repository to staff at the University of Lincoln. Consists of ten reasons why academic authors should consider depositing copies of their work in the Repository.

Data repositories for medical education research: issues and recommendations.

Science.gov (United States)

Schwartz, Alan; Pappas, Cleo; Sandlow, Leslie J

2010-05-01

The authors explore issues surrounding digital repositories with the twofold intention of clarifying their creation, structure, content, and use, and considering the implementation of a global digital repository for medical education research data sets-an online site where medical education researchers would be encouraged to deposit their data in order to facilitate the reuse and reanalysis of the data by other researchers. By motivating data sharing and reuse, investigators, medical schools, and other stakeholders might see substantial benefits to their own endeavors and to the progress of the field of medical education.The authors review digital repositories in medicine, social sciences, and education, describe the contents and scope of repositories, and present extant examples. The authors describe the potential benefits of a medical education data repository and report results of a survey of the Society for Directors of Research in Medicine Education, in which participants responded to questions about data sharing and a potential data repository. Respondents strongly endorsed data sharing, with the caveat that principal investigators should choose whether or not to share data they collect. A large majority believed that a repository would benefit their unit and the field of medical education. Few reported using existing repositories. Finally, the authors consider challenges to the establishment of such a repository, including taxonomic organization, intellectual property concerns, human subjects protection, technological infrastructure, and evaluation standards. The authors conclude with recommendations for how a medical education data repository could be successfully developed.

Damage-plasticity model of the host rock in a nuclear waste repository

Energy Technology Data Exchange (ETDEWEB)

Koudelka, Tomáš; Kruis, Jaroslav, E-mail: kruis@fsv.cvut.cz [Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

2016-06-08

The paper describes damage-plasticity model for the modelling of the host rock environment of a nuclear waste repository. Radioactive Waste Repository Authority in Czech Republic assumes the repository to be in a granite rock mass which exhibit anisotropic behaviour where the strength in tension is lower than in compression. In order to describe this phenomenon, the damage-plasticity model is formulated with the help of the Drucker-Prager yield criterion which can be set to capture the compression behaviour while the tensile stress states is described with the help of scalar isotropic damage model. The concept of damage-plasticity model was implemented in the SIFEL finite element code and consequently, the code was used for the simulation of the Äspö Pillar Stability Experiment (APSE) which was performed in order to determine yielding strength under various conditions in similar granite rocks as in Czech Republic. The results from the performed analysis are presented and discussed in the paper.

Implementation of the Brazilian national repository

International Nuclear Information System (INIS)

Tello, Cledola Cassia Oliveira de

2013-01-01

Ionizing radiation in Brazil is used in electricity generation, medicine, industry, agriculture and for research and development purposes. All these activities can generate radioactive waste. At this point, in Brazil, the use of nuclear energy and radioisotopes justifies the construction of a national repository for radioactive wastes of low and intermediate-level. According to Federal Law No. 10308, Brazilian National Commission for Nuclear Energy (CNEN) is responsible for designing and constructing the intermediate and final storages for radioactive wastes. Additionally, a restriction on the construction of Angra 3 is that the repository is under construction until its operation start, attaining some requirements of the Brazilian Environmental Regulator (IBAMA). The RBMN Project (Repository for Low and Intermediate-Level Radioactive Wastes) aims at the implantation of a National Repository for disposal of low and intermediate-level of radiation wastes. This Project has some aspects that are unique in the Brazilian context, especially referring to the time between its construction and the end of its institutional period. This time is about 360 years, when the area will be released for unrestricted uses. It means that the Repository must be safe and secure for more than three hundred years, which is longer than half of the whole of Brazilian history. This aspect is very new for the Brazilian people, bringing a new dimension to public acceptance. Another point is this will be the first repository in South America, bringing a real challenge for the continent. The current status of the Project is summarized. (author)

Panel report on coupled thermo-mechanical-hydro-chemical processes associated with a nuclear waste repository

International Nuclear Information System (INIS)

Tsang, C.F.; Mangold, D.C.

1984-07-01

Four basic physical processes, thermal, hydrological, mechanical and chemical, are likely to occur in 11 different types of coupling during the service life of an underground nuclear waste repository. A great number of coupled processes with various degrees of importance for geological repositories were identified and arranged into these 11 types. A qualitative description of these processes and a tentative evaluation of their significance and the degree of uncertainty in prediction is given. Suggestions for methods of investigation generally include, besides theoretical work, laboratory and large scale field testing. Great efforts of a multidisciplinary nature are needed to elucidate details of several coupled processes under different temperature conditions in different geological formations. It was suggested that by limiting the maximum temperature to 100 0 C in the backfill and in the host rock during the whole service life of the repository the uncertainties in prediction of long-term repository behavior might be considerably reduced

Panel report on coupled thermo-mechanical-hydro-chemical processes associated with a nuclear waste repository

Energy Technology Data Exchange (ETDEWEB)

Tsang, C.F.; Mangold, D.C. (eds.)

1984-07-01

Four basic physical processes, thermal, hydrological, mechanical and chemical, are likely to occur in 11 different types of coupling during the service life of an underground nuclear waste repository. A great number of coupled processes with various degrees of importance for geological repositories were identified and arranged into these 11 types. A qualitative description of these processes and a tentative evaluation of their significance and the degree of uncertainty in prediction is given. Suggestions for methods of investigation generally include, besides theoretical work, laboratory and large scale field testing. Great efforts of a multidisciplinary nature are needed to elucidate details of several coupled processes under different temperature conditions in different geological formations. It was suggested that by limiting the maximum temperature to 100{sup 0}C in the backfill and in the host rock during the whole service life of the repository the uncertainties in prediction of long-term repository behavior might be considerably reduced.

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

Deep repository for long-lived low- and intermediate-level waste. Preliminary safety assessment

International Nuclear Information System (INIS)

1999-11-01

A preliminary safety assessment has been performed of a deep repository for long-lived low- and intermediate-level waste, SFL 3-5. The purpose of the study is to investigate the capacity of the facility to act as a barrier to the release of radionuclides and toxic pollutants, and to shed light on the importance of the location of the repository site. A safety assessment (SR 97) of a deep repository for spent fuel has been carried out at the same time. In SR 97, three hypothetical repository sites have been selected for study. These sites exhibit fairly different conditions in terms of hydrogeology, hydrochemistry and ecosystems. To make use of information and data from the SR 97 study, we have assumed that SFL 3-5 is co-sited with the deep repository for spent fuel. A conceivable alternative is to site SFL 3-5 as a completely separate repository. The focus of the SFL 3-5 study is a quantitative analysis of the environmental impact for a reference scenario, while other scenarios are discussed and analyzed in more general terms. Migration in the repository's near- and far-field has been taken into account in the reference scenario. Environmental impact on the three sites has also been calculated. The calculations are based on an updated forecast of the waste to be disposed of in SFL 3-5. The forecast includes radionuclide content, toxic metals and other substances that have a bearing on a safety assessment. The safety assessment shows how important the site is for safety. Two factors stand out as being particularly important: the water flow at the depth in the rock where the repository is built, and the ecosystem in the areas on the ground surface where releases may take place in the future. Another conclusion is that radionuclides that are highly mobile and long-lived, such as 36 Cl and 93 Mo , are important to take into consideration. Their being long-lived means that barriers and the ecosystems must be regarded with a very long time horizon

The development of safeguards for geological repositories

International Nuclear Information System (INIS)

Van der Meer, K.

2009-01-01

Traditionally, research and development on geological repositories for High Level Waste (HLW) focuses on the short- and long-term safety aspects of the repository. If the repository will also be used for the disposal of spent fuel, safeguards aspects have to be taken into account. Safety and safeguards requirements may be contradictory; the safety of a geological repository is based on the non-intrusion of the geological containment, while safeguards require regular inspections of position and amount of the spent fuel. Examples to reconcile these contradictory requirements are the use of information required for the safety assessment of the geological repository for safeguards purposes and the adaptation of the safeguards approach to use non-intrusive inspection techniques. The principles of an inspection approach for a geological repository are now generally accepted within the IAEA. The practical applicability of the envisaged inspection techniques is still subject to investigation. It is specifically important for the Belgian situation that an inspection technique can be used in clay, the geological medium in which Belgium intends to dispose its HLW and spent fuel. The work reported in this chapter is the result of an international cooperation in the framework of the IAEA, in which SCK-CEN participates

Investigative study of standards for digital repositories and related services

CERN Document Server

Foulonneau, Muriel; Badolato, Anne-Marie

2008-01-01

This study is meant for institutional repository managers, service providers, repository software developers and generally, all players taking an active part in the creation of the digital repository infrastructure for e-research and e-learning. It reviews the current standards, protocols and applications in the domain of digital repositories. Special attention is being paid to the interoperability of repositories to enhance the exchange of data in repositories. It aims to stimulate discussion about these topics and supports initiatives for the integration of and, where needed, development of

Development of emergency arrangements for the transport of radioactive waste to a deep repository

International Nuclear Information System (INIS)

Gray, I.L.S.; Hutchinson, D.L.; Burgess, M.H.; Higson, J.; Randall, M.A.

1993-01-01

This paper summarises the results of the studies and discussions which have led to the recommendation that Nirex should adopt NIREP as the Emergency Plan for the proposed transport arrangements of radioactive waste to the proposed UK deep repository for the disposal of low level and intermediate level waste. Although NIREP is currently specific to the road transport of radioactive materials, it is in the process of being extended to cover their transport by rail. An extended version of NIREP, covering both road and rail transport, could be operational by the end of 1992. NIREP is an established plan which meets all the current legal requirements and is flexible enough to accommodate any likely changes in legislation in the future. It is compatible with the Planning Basis and meets the requirements of the Emergency Plan Specification. The extended version of NIREP will be subject to an annual full-scale exercise and the Plan should be well-proven by the time that transport of waste packages to the repository commences. (J.P.N.)

Saturation of compacted bentonite under repository conditions: long-term experimental evidences

International Nuclear Information System (INIS)

Villar, M.V.; Martin, P.L.; Gomez-Espina, R.; Garcia-Sineriz, J.L.; Barcena, I.; Lloret, A.

2010-01-01

Document available in extended abstract form only. A current design for engineered barriers in the context of high-level radioactive waste disposal includes bentonite compacted blocks initially unsaturated. The heat released by the waste will induce high temperatures in the bentonite barrier. It is expected that full saturation of the buffer be reached before the dissipation of the thermal gradient. However, it still remains unclear whether the high temperatures around the canister would hinder the full saturation of the inner part of the barrier or just delay it. This paper summarises the information gathered in the last 15 years on the saturation of compacted FEBEX bentonite by means of different scale laboratory tests, a big-scale mock-up test and a real-scale in situ test, that were performed in order to simulate the conditions of the clay barrier in the repository and better understand the hydration/heating processes and their consequences on bentonite performance. FEBEX is a Spanish bentonite composed mainly of montmorillonite (about 92%). In the tests it has been used compacted with its hygroscopic water content (14%) at dry densities between 1.6 and 1.7 g/cm 3 , which is the range expected in the repository. For these densities the saturated permeability of the bentonite is about 3.10 -14 m/s and its swelling pressure 8 MPa. The FEBEX in situ test is being performed under natural conditions and at full scale within a drift excavated in the underground laboratory managed by NAGRA at the Grimsel Test Site (Switzerland). The thickness of the bentonite barrier is of 65 cm, and the surface heater temperature is 100 C. After five years of heating, and according to the sensors measurements, the bentonite closer to the heater had water contents below the initial ones, although they were recovering after the intense initial drying. On the contrary, for the same period of time, the sensors located at the same distance from the gallery wall, but in an area not

Training courses on integrated safety assessment modelling for waste repositories

International Nuclear Information System (INIS)

Mallants, D.

2007-01-01

Near-surface or deep repositories of radioactive waste are being developed and evaluated all over the world. Also, existing repositories for low- and intermediate-level waste often need to be re-evaluated to extend their license or to obtain permission for final closure. The evaluation encompasses both a technical feasibility as well as a safety analysis. The long term safety is usually demonstrated by means of performance or safety assessment. For this purpose computer models are used that calculate the migration of radionuclides from the conditioned radioactive waste, through engineered barriers to the environment (groundwater, surface water, and biosphere). Integrated safety assessment modelling addresses all relevant radionuclide pathways from source to receptor (man), using in combination various computer codes in which the most relevant physical, chemical, mechanical, or even microbiological processes are mathematically described. SCK-CEN organizes training courses in Integrated safety assessment modelling that are intended for individuals who have either a controlling or supervising role within the national radwaste agencies or regulating authorities, or for technical experts that carry out the actual post-closure safety assessment for an existing or new repository. Courses are organised by the Department of Waste and Disposal

Refinancing of the search for a repository and of the repository for heat generating radioactive Waste. Pt. 2

International Nuclear Information System (INIS)

Moench, Christoph

2013-01-01

Part I of this article, which appeared in the preceding issue, described in general terms the background to the search for a disposal site and the result of the exploration to date of the repository, which would appear to be suitable from a mining standpoint according to the present knowledge. According to the rules in effect up to now, the exploration and construction would be financed by advance payments on the contributions of the waste producing companies, in particular the utility companies. The working draft of an 'Act on the search for and selection of a site for a repository for heat generating radioactive waste' (Gesetz zur Suche und Auswahl eines Standortes fuer ein Endlager fuer waermeentwickelnde radioaktive Abfaelle) from autumn 2012 provides for a new version of section 21b Atomic Energy Act, under which the costs for 'carrying out a repository selection procedure pursuant to the Repository Selection Act (Standort-auswahlgesetz)' would be allocated to the future users of the repository who are obliged to make contributions as a 'necessary expense'. Part II evaluates this provision of the working draft on the basis of the financial constitutional law. A comparison of sites is not a measure that could be allocated to the future users of the repository who are obliged to make contributions as a 'necessary expense'. Moreover, there is a lack of responsibility for the financing and of a legally relevant advantage that would be conferred by a cumulative alternative repository search for the later users of the repository who are obliged to provide the pre-financing. The costs can therefore not be allocated to the later users as either a contribution or a special charge, not even by way of an association with mandatory membership (Zwangsverband). They must be borne by the state. Consequently, the allocation stipulated by provision would constitute an impermissible charge under financial constitutional law. (orig.)

Investigations on the populations of introduced and resident micro-organisms in deep repositories and their effects on containment of radioactive wastes

International Nuclear Information System (INIS)

West, J.M.; Arme, S.C.; Christofi, N.; Philp, J.C.

1986-01-01

The present study has sought to establish basic facts concerning the importance of microbial presence in a radioactive waste repository. These are: (1) establishing the presence of microbes in relevant geological formations; (2) defining the importance of isolated groups to radioactive waste containment; (3) establishing the ability of sampled microbes to tolerate repository environmental conditions; (4) conducting preliminary work on microbial ability to influence radionuclide migration characteristics; (5) attempting basic modelling of the effects of micro-organisms on containment and radionuclide migration. Results have shown that micro-organisms of significance (e.g. sulphur cycle bacteria) are present in relevant formations. These groups can tolerate repository conditions and influence migration studies. Their growth, however, would seem to be limited by the nutrient availability. Simple modelling has concentrated on conservative calculations on the constraints of maximum effects of microbial contamination of a high-level waste repository

Thermo-mechanical analysis for multi-level HLW repository concept

International Nuclear Information System (INIS)

Kwon, Sang Ki; Choi, Jong Won

2004-01-01

This work aims to investigate the influence of design parameters for the underground high-level nuclear waste repository with multi-level concept. B. Necessity o In order to construct an HLW repository in deep underground, it is required to select a site, which is far from major discontinuities. To dispose the whole spent fuels generated from the Korean nuclear power plants in a repository, the underground area of about 4km 2 is required. This would be a constraints for selecting an adequate repository site. It is recommended to dispose the two different spent fuels, PWR and CANDU, in different areas at the operation efficiency point of view. It is necessary to investigate the influence of parameters, which can affect the stability of multi-level repository. It is also needed to consider the influence of heat generated from the HLW and the high in situ stress in deep location. Therefore, thermo-mechanical coupling analysis should be carried out and the results should be compared with the results from single-level repository concept. Three-dimensional analysis is required to model the disposal tunnel and deposition hole. It is recommended to use the Korean geological condition and actually measured rock properties in Korea in order to achieve reliable modeling results. A FISH routine developed for effective modeling of Thermal-Mechanical coupling was implemented in the modeling using FLAC3D, which is a commercial three-dimensional FDM code. The thermal and mechanical properties of rock and rock mass achieved from Yusung drilling site, were used for the computer modeling. Different parameters such as level distance, waste type disposed on different levels, and time interval between the operation on different levels, were considered in the three-dimensional analysis. From the analysis, it was possible to derive adequate multi-level repository concept. Results and recommendations for application From the thermal-mechanical analysis for the multi-level repository

Assessment of crushed salt consolidation and fracture healing processes in a nuclear waste repository in salt

International Nuclear Information System (INIS)

1984-11-01

For a nuclear waste repository in salt, two aspects of salt behavior are expected to contribute to favorable conditions for waste isolation. First, consolidation of crushed salt backfill due to creep closure of the underground openings may result in a backfill barrier with low permeability. Second, fractures created in the salt by excavation may heal under the influence of stress and temperature following sealing. This report reviews the status of knowledge regarding crushed salt consolidation and fracture healing, provides analyses which predict the rates at which the processes will occur under repository conditions, and develops requirements for future study. Analyses of the rate at which crushed salt will consolidate are found to be uncertain because of unexplained wide variation in the creep properties of crushed salt obtained from laboratory testing, and because of uncertainties in predictions of long term closure rates of openings in salt. This uncertainty could be resolved to a large degree by additional laboratory testing of crushed salt. Similarly, additional testing of fracture healing processes is required to confirm that healing will be effective under repository conditions. Extensive references, 27 figures, 5 tables

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

Groundwater flow modeling of periods with temperate climate conditions for use in a safety assessment of a repository for spent nuclear fuel - 59154

International Nuclear Information System (INIS)

Joyce, Steven; Hartley, Lee; Simpson, Trevor

2012-01-01

Document available in abstract form only. Full text of publication follows: As a part of the license application for a final repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Company (SKB) has prepared a safety report (SR-Site) that assesses the long-term radiological safety after closure of a repository located at 500 m depth in the Forsmark area, c. 120 km north of Stockholm. The movement and composition of groundwater affect both the key pathways for radionuclide migration and the performance of engineered barriers, and hence are important issues that have to be considered and modelled as part of quantitative assessment calculations. This presentation describes the groundwater flow modelling studies that have been performed to represent the post-closure hydrogeological and hydrochemical situations during temperate climate conditions, and how these are used to support safety assessment calculations and arguments. The collation and implementation of onsite hydrogeological and hydrogeochemical data from the surface based site investigations at Forsmark are used as the basis for defining a reference case for the natural hydrogeological situation at the site (hydrogeological base case). Areas of uncertainty within the current site understanding and the engineered system are examined by a series of flow model variants

Electronic Repository of Russian Historical Statistics

NARCIS (Netherlands)

Tykhonov, Vyacheslav; Kessler, Gijs; Markevich, Andrei; de Vries, Jerry

2014-01-01

The Electronic Repository for Russian Historical Statistics brings together data extracted from various published and unpublished sources in one place. Its principal focus is Russian economic and social history of the last three centuries (18th-21st). The repository caters to the needs of the

1992 Annual Capacity Report

International Nuclear Information System (INIS)

1993-05-01

The Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (10 CFR Part 961) requires the Department of Energy (DOE) to issue an Annual Capacity Report (ACR) for planning purposes. This report is the fifth in the series published by DOE. In May 1993, DOE published the 1992 Acceptance Priority Ranking (APR) that established the order in which DOE will allocate projected acceptance capacity. As required by the Standard Contract, the acceptance priority ranking is based on the date the spent nuclear fuel (SNF) was permanently discharged, with the owners of the oldest SNF, on an industry-wide basis, given the highest priority. The 1992 ACR applies the projected waste acceptance rates in Table 2.1 to the 1992 APR, resulting in individual allocations for the owners and generators of the SNF. These allocations are listed in detail in the Appendix, and summarized in Table 3.1. The projected waste acceptance rates for SNF presented in Table 2.1 are nominal and assume a site for a Monitored Retrievable Storage (MRS) facility will be obtained; the facility will initiate operations in 1998; and the statutory linkages between the MRS facility and the repository set forth in the Nuclear Waste Policy Act of 1982, as amended (NWPA), will be modified. During the first ten years following projected commencement of Civilian Radioactive Waste Management System (CRWMS) operation, the total quantity of SNF that could be accepted is projected to be 8,200 metric tons of uranium (MTU). This is consistent with the storage capacity licensing conditions imposed on an MRS facility by the NWPA. The annual acceptance rates provide an approximation of the system throughput and are subject to change as the program progresses

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

Review of the potential effects of alkaline plume migration from a cementitious repository for radioactive waste

International Nuclear Information System (INIS)

Savage, D.

1997-01-01

Extensive use of cement and concrete is envisaged in the construction of geological repositories for low and intermediate-level radioactive wastes, both for structural, and encapsulation and backfilling purposes. Saturation of these materials with groundwater may occur in the post-closure period of disposal, producing a hyperalkaline pore fluid with a pH in the range 10-13.5. These pore fluids have the potential to migrate from the repository according to local groundwater flow conditions and react chemically with the host rock. These chemical reactions may affect the rock's capacity to retard the migration of radionuclides released from the repository after the degradation of the waste packages. The effects of these chemical reactions on the behaviour of the repository rock as a barrier to waste migration need to be investigated for the purposes of assessing the safety of the repository design (so-called 'safety assessment' or 'performance assessment'). The objectives of the work reported here were to: identify those processes influencing radionuclide mobility in the geosphere which could be affected by plume migration; review literature relevant to alkali-rock reaction; contact organisations carrying out relevant research and summarise their current and future activities; and make recommendations how the effects of plume migration can be incorporated into models of repository performance assessment. (author)

Carbon-14 speciation during anoxic corrosion of activated steel in a repository environment

Energy Technology Data Exchange (ETDEWEB)

Wieland, E.; Cvetkovic, B.Z.; Kunz, D. [Paul Scherrer Institute, Villigen (Switzerland). Lab. for Waste Management; Salazar, G.; Szidat, S. [Bern Univ. (Switzerland). Dept. of Chemistry and Biochemistry and Oeschger Centre for Climate Change Research

2018-01-15

Radioactive waste contains significant amounts of {sup 14}C which has been identified a key radionuclide in safety assessments. In Switzerland, the {sup 14}C inventory of a cement-based repository for low- and intermediate-level radioactive waste (L/ILW) is mainly associated with activated steel (∝85 %). {sup 14}C is produced by {sup 14}N activation in steel parts exposed to thermal neutron flux in light water reactors. Release of {sup 14}C occurs in the near field of a deep geological repository due to anoxic corrosion of activated steel. Although the {sup 14}C inventory of the L/ILW repository and the sources of {sup 14}C are well known, the formation of {sup 14}C species during steel corrosion is only poorly understood. The aim of the present study was to identify and quantify the {sup 14}C-bearing carbon species formed during the anoxic corrosion of iron and steel and further to determine the {sup 14}C speciation in a corrosion experiment with activated steel. All experiments were conducted in conditions similar to those anticipated in the near field of a cement-based repository.

Numerical simulation of groundwater flow in LILW Repository site:I. Groundwater flow modeling

Energy Technology Data Exchange (ETDEWEB)

Park, Koung Woo; Ji, Sung Hoon; Kim, Chun Soo; Kim, Kyoung Su [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Ji Yeon [Korea Hydro and Nuclear Power Co. Ltd., Seoul (Korea, Republic of)

2008-12-15

Based on the site characterization works in a low and intermediate level waste (LILW) repository site, the numerical simulations for groundwater flow were carried out in order to understand the groundwater flow system of repository site. To accomplish the groundwater flow modeling in the repository site, the discrete fracture network (DFN) model was constructed using the characteristics of fracture zones and background fractures. At result, the total 10 different hydraulic conductivity(K) fields were obtained from DFN model stochastically and K distributions of constructed mesh were inputted into the 10 cases of groundwater flow simulations in FEFLOW. From the total 10 numerical simulation results, the simulated groundwater levels were strongly governed by topography and the groundwater fluxes were governed by locally existed high permeable fracture zones in repository depth. Especially, the groundwater table was predicted to have several tens meters below the groundwater table compared with the undisturbed condition around disposal silo after construction of underground facilities. After closure of disposal facilities, the groundwater level would be almost recovered within 1 year and have a tendency to keep a steady state of groundwater level in 2 year.

Project ANSICHT. Final repository concept and backfilling and sealing concept for the final repository site model SUeD; Projekt ANSICHT. Endlagerkonzept sowie Verfuell- und Verschlusskonzept fuer das Endlagerstandortmodell SUeD. Technischer Bericht

Energy Technology Data Exchange (ETDEWEB)

Jobmann, Michael; Lommerzheim, Andree

2015-08-03

In the frame of ANSICHT the methodology for the demonstration of safe enclosure for high-level heat generating radioactive wastes is described. The report is based on the safety requirements for final repository concepts and shows a first backfilling and sealing concept that was developed for the final repository site model SUeD. The final repository model SUeD is based on a horizontal line storage concept, the Gorleben (VSG) and ERATO container concept and the mine layout were adopted and adapted to the given conditions. The backfill and sealing concept includes migration barriers, line closures and shaft closures in the frame of a redundant and diverse enclosure system. For all technical and geotechnical barrier components the long-term functional requirements were defined. The backfilling concept of underground cavities considers the variety of possible cavities in the line and infrastructure areas.

Fons antic i repositoris universitaris a Espanya

Directory of Open Access Journals (Sweden)

Herrera Morillas, José Luis

2015-12-01

Full Text Available Es mostra la presència de col·leccions de fons antic en els repositoris de les biblioteques universitàries espanyoles després d'analitzar tots els repositoris. Per a aquesta anàlisi, com a part de la metodologia emprada, s'ha elaborat un model o llista que consta d'onze elements. Del conjunt de les universitats espanyoles, seixanta tenen repositoris, vint-i-vuit dels quals (16,8 % disposen de col·leccions de fons antic. Com que del concepte de repositori institucional no sembla desprendre's que tingui com a finalitat incloure aquest tipus de col·leccions, es reflexiona sobre la peculiaritat que una part dels repositoris universitaris espanyols inclogui col·leccions d'aquestes característiques.Se muestra la presencia de colecciones de fondo antiguo en los repositorios de las bibliotecas universitarias españolas después de analizar todos los repositorios. Para este análisis, como parte de la metodología empleada, se ha elaborado un modelo o lista que consta de once elementos. Del conjunto de las universidades españolas, sesenta cuentan con repositorios y, de estos, veintiocho (16,8 % disponen de colecciones de fondo antiguo. Debido a que del concepto de repositorio institucional no parece desprenderse que tenga como finalidad albergar este tipo de colecciones, se hace una reflexión sobre la peculiaridad de que parte de los repositorios universitarios españoles incluya colecciones de estas características.This paper uses an analysis of the repositories of Spanish universities to identify which institutions contain rare book and manuscript collections. The method used in this analysis involved examining each university on the basis of a list comprising eleven elements. A total of 60 universities were found to have repositories but only 28 (16.8 % of these contained rare book and manuscript collections. In the light of these figures, which suggest that Spanish university repositories do not generally consider the preservation of rare

Decompression of magma into repository tunnels

NARCIS (Netherlands)

Bokhove, Onno; Woods, A.W.

2002-01-01

It is nontrivial to find and design safe repository sites for nuclear waste. It appears common sense to drill tunnels as repository sites in a mountain in remote and relatively dry regions. However, erosion of the waste canisters by naturally abundant chemicals in the mountains water cycle remains a

Paper and digital repositories in the United States

Directory of Open Access Journals (Sweden)

David F. Kohl

2003-09-01

Full Text Available What you've asked me to talk about today is basically what can libraries do with all the stuff they have and continue to get. Where do we put it all; what do we do with it? As we know, libraries have three core functions: collecting, organizing and preserving the key documents of the human enterprise. And, with apologies to Saint Paul, the greatest of these is preservation. For without preservation neither of the first two ultimately matter. My assignment this morning is to bring you up to date on one specific aspect of the preservation function, library repositories, and indeed, library repository developments in the US. The plan for this morning's presentation is the following: after a brief background review to give us a context for American developments we will examine first the various kinds of print repositories and then the various initiatives for electronic repositories. Because other presentations at this conference deal with electronic repositories, the main focus today will be on U.S. print repositories.

Institutional Repository Sebagai Sarana Komunikasi Ilmiah Yang Sustainable Dan Reliable

Directory of Open Access Journals (Sweden)

Faizuddin Harliansyah

2016-07-01

Full Text Available Abstract; Institutional repositories development has drawn the attention of many scholars throughout the world. Using the keywords ‘institutional repositories’, there are over 300 peer-reviewed articles related on the topic has been indexed in Library, Information Science, & Technology Abstracts (LISTA and SCOPUS. There are also hundreds of theses, dissertations, and websites dedicated on this blooming trends. These are proofs that the importance of IR in higher education has been acknowledged by many professionals in the field. This paper aims at clarifying the role of repositories in strengthening scholarly communication in higher education and research institution and explaining some basic repositories concepts (types of repositories and their characteristics, as well as exploring its relations with open access movement, the development ideas, and resources that could be kept in repositories and deposit policies. Abstrak; Pengembangan institutional repositories telah banyak menyita perhatian dari kalangan ilmiah di seluruh dunia. Melalui kata kunci ‘institutional repositories’, ada lebih dari 300 artikel terulas mitra bestari yang berhubungan dengan topik ini, yang telah terindeks di Library, Information Science, & Technology Abstracts (LISTA, dan SCOPUS. Terdapat juga ratusan tesis, disertasi, dan website yang mengulas trend ini. Inilah bukti bahwa pentingnya institutional repositories (IR telah dipahami oleh para profesional di bidangnya. Tulisan ini akan menjelaskan aturan-aturan repository dalam memperkuat komunikasi ilmiah di perguruan tinggi dan lembaga riset, menjelaskan konsep-konsep dasar repositories, termasuk tipe-tipe repository dan karakteristiknya. Tulisan ini juga akan memperdalam konsep repositories dalam hubungannya dengan gerakan open access, pengembangan ide-ide, sumber-sumber ilmiah yang dapat disimpan di repositories, serta kebijakan penyimpanan di dalamnya.

Environmental issues of repository licensing: an evaluation of a hypothetical high-level radioactive waste repository

International Nuclear Information System (INIS)

Owen, J.L.; McGinnis, J.T.; Harper, C.M.; Battelle Columbus Labs., OH)

1982-01-01

This paper presents results of an environmental assessment conducted under the direction of the Office of Nuclear Waste Isolation as part of the National Waste Terminal Storage program. The study defined a range of potential environmental effects of constructing, operating, decommissioning, and long-term isolation of a nuclear waste repository. The analytical methodology used to determine potential environmental effects required definition of a hypothetical environmental setting and repository. Potentially applicable regulatory requirements were identified and were used as guidelines to evaluate permitting feasibility. The environmental effects of repository development were analyzed for the two major time periods of concern: short term (the period of construction, operation, and decommissioning) and long term (the isolation period after decommissioning). As a result of this analysis, major environmental uncertainties and issues were identified. 11 references, 5 figures

KBS annual report 1981

International Nuclear Information System (INIS)

1982-05-01

The nuclear power utilities have commissioned the jointly owned Swedish Nuclear Fuel Supply Company (SKBF) to assume responsibility for a safe handling of the waste and a safe final storage. KBS is the department within SKBF that is responsible for research and development within the area of radioactive waste management. The government agency of PRAV (the National Council for Radioactive Waste) was dissolved as of mid-year 1981 and its research activities were transferred to SKBF/KBS. Simultaneosly, the National Board for Spent Nuclear Fuel, NAK, was created and charged with the duties of overseeing the work being conducted by SKBF within the nuclear waste field and administering the funds that are to be set up for the financing of future waste management activities. The present annual report describes activities within KBS during 1981. The work conducted during the year has been concentrated on three areas: 1) A systematic review has begun of geologically interesting areas in Sweden that might be suitable as sites for a final repository for highlevel waste or spent fuel. 10-20 areas are scheduled for study during the 1980s. 2) The chemical research has been broadened in order to future understanding of the chemical interplay that exists in the repository between the canister material, the buffer, the waste matrix and the groundwater. The retardation effects associated with the transport of radioactive elements with the groundwater in the bedrock also constitute an important subject of these studies. 3) The preliminary planning and engineering of a final repository for low- and medium-level operating waste from the Swedish reactors is in progress. The aim is to submit an application during the spring of 1982 for permission to build the facility at the Forsmark Nuclear Power Station. (Author)

Analysis of computational vulnerabilities in digital repositories

Directory of Open Access Journals (Sweden)

Valdete Fernandes Belarmino

2015-04-01

Full Text Available Objective. Demonstrates the results of research that aimed to analyze the computational vulnerabilities of digital directories in public Universities. Argues the relevance of information in contemporary societies like an invaluable resource, emphasizing scientific information as an essential element to constitute scientific progress. Characterizes the emergence of Digital Repositories and highlights its use in academic environment to preserve, promote, disseminate and encourage the scientific production. Describes the main software for the construction of digital repositories. Method. The investigation identified and analyzed the vulnerabilities that are exposed the digital repositories using Penetration Testing running. Discriminating the levels of risk and the types of vulnerabilities. Results. From a sample of 30 repositories, we could examine 20, identified that: 5% of the repositories have critical vulnerabilities, 85% high, 25% medium and 100% lowers. Conclusions. Which demonstrates the necessity to adapt actions for these environments that promote informational security to minimizing the incidence of external and / or internal systems attacks.Abstract Grey Text – use bold for subheadings when needed.

New Roles, New Responsibilities: Examining Training Needs of Repository Staff

Directory of Open Access Journals (Sweden)

Natasha Simons

2012-05-01

Full Text Available INTRODUCTION Institutional repositories play a critical role in the research lifecycle. Funding agencies are increasingly seeking an improved return on their investment in research. Repositories facilitate this process by providing storage of, and access to, institutional research outputs and, more recently, research data. While repositories are generally managed within the academic library, repository staff require different skills and knowledge compared with traditional library roles. This study reports on a survey of Australasian institutional repository staff to identify skills and knowledge sets. METHODS Institutional repository staff working at universities in Australia and New Zealand were invited to participate in an online survey which incorporated both open and closed-ended question types. RESULTS The survey found significant gaps in the current provision of formal training and coursework related to institutional repositories, which echoed findings in the United Kingdom, Italy, and the United States. DISCUSSION There is clearly a need for more and varied training opportunities for repository professionals. Repository work requires a specific set of skills that can be difficult to find and institutions will benefit from investing in training and ongoing development opportunities for repository staff. CONCLUSION The data from this study could be used to facilitate staff recruitment, development, training, and retention strategies.

Semantic Linking of Learning Object Repositories to DBpedia

Science.gov (United States)

Lama, Manuel; Vidal, Juan C.; Otero-Garcia, Estefania; Bugarin, Alberto; Barro, Senen

2012-01-01

Large-sized repositories of learning objects (LOs) are difficult to create and also to maintain. In this paper we propose a way to reduce this drawback by improving the classification mechanisms of the LO repositories. Specifically, we present a solution to automate the LO classification of the Universia repository, a collection of more than 15…

Iron-nickel alloys as canister material for radioactive waste disposal in underground repositories

International Nuclear Information System (INIS)

Apps, J.A.

1982-01-01

Canisters containing high-level radioactive waste must retain their integrity in an underground waste repository for at least one thousand years after burial (Nuclear Regulatory Commission, 1981). Since no direct means of verifying canister integrity is plausible over such a long period, indirect methods must be chosen. A persuasive approach is to examine the natural environment and find a suitable material which is thermodynamically compatible with the host rock under the environmental conditions with the host rock under the environmental conditions expected in a waste repository. Several candidates have been proposed, among them being iron-nickel alloys that are known to occur naturally in altered ultramafic rocks. The following review of stability relations among iron-nickel alloys below 350 0 C is the initial phase of a more detailed evaluation of these alloys as suitable canister materials

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...

Researching radioactive waste disposal. [Underground repository

Energy Technology Data Exchange (ETDEWEB)

Feates, F; Keen, N [UKAEA Research Group, Harwell. Atomic Energy Research Establishment

1976-02-16

At present it is planned to use the vitrification process to convert highly radioactive liquid wastes, arising from nuclear power programme, into glass which will be contained in steel cylinders for storage. The UKAEA in collaboration with other European countries is currently assessing the relative suitability of various natural geological structures as final repositories for the vitrified material. The Institute of Geological Sciences has been commissioned to specify the geological criteria that should be met by a rock structure if it is to be used for the construction of a repository though at this stage disposal sites are not being sought. The current research programme aims to obtain basic geological data about the structure of the rocks well below the surface and is expected to continue for at least three years. The results in all the European countries will then be considered so that the United Kingdom can choose a preferred method for isolating their wastes. It is only at that stage that a firm commitment may be made to select a site for a potential repository, when a far more detailed scientific research study will be instituted. Heat transfer problems and chemical effects which may occur within and around repositories are being investigated and a conceptual design study for an underground repository is being prepared.

Cross Institutional Cooperation on a Shared Bit Repository

DEFF Research Database (Denmark)

Zierau, Eld; Kejser, Ulla Bøgvad

2013-01-01

This paper explores how independent institutions, such as archives and libraries, can cooperate on managing a shared bit repository with bit preservation, in order to use their resources for preservation in a more cost-effective way. It uses the OAIS Reference Model to provide a framework...... for systematically analysing institutions technical and organisational requirements for a remote bit repository. Instead of viewing a bit repository simply as Archival Storage for the institutions repositories, we argue for viewing it as consisting of a subset of functions from all entities defined by the OAIS...... Reference Model. The work is motivated by and used in a current Danish feasibility study for establishing a national bit repository. The study revealed that depending on their missions and the collections they hold, the institutions have varying requirements e.g. for bit safety, accessibility...

Cross Institutional Cooperation on a Shared Bit Repository

DEFF Research Database (Denmark)

Zierau, Eld; Kejser, Ulla Bøgvad

2010-01-01

This paper explores how independent institutions, such as archives and libraries, can cooperate on managing a shared bit repository with bit preservation in order to use their resources for preservation n in a more cost-effective way. It uses the OAIS Reference Model to provide a framework...... for systematically analysing the technical and organizational requirements of institutions for a remote bit repository. Instead of viewing a bit repository simply as Archival Storage for the institutions’ repositories, we argue for viewing it as consisting of a subset of functions from all entities defined...... by the OAIS Reference Model. The work is motivated by and used in a current Danish feasibility study for establishing a national bit repository. The study revealed that depending on their missions and the collections they hold, the institutions have varying requirements, such as for bit safety, accessibility...

On ocean island geological repository - a second-generation option for disposal of spent fuel and high-level waste

International Nuclear Information System (INIS)

Forsberg, C.W.

1993-01-01

The concept of an ocean subseabed geological high-level waste repository with access via an ocean island is discussed. The technical advantages include, in addition to geologic waste isolation, geographical isolation, near-zero groundwater flow through the disposal site, and near-infinite ocean dilution as a backup in the event of a failure of the repository geological waste isolation system. The institutional advantages may include reduced siting problems and the potential of creating an international waste repository. Establishment of a repository accepting wastes from many countries would allow cost sharing, aid international nonproliferation goals, and ensure proper disposal of spent fuel from developing countries. Major uncertainties that are identified in this concept are the uncertainties in rock conditions at waste disposal depths, costs, and ill-defined institutional issues

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...

Basalt Waste Isolation Project. Annual report, fiscal year 1980

International Nuclear Information System (INIS)

1980-11-01

During this fiscal year the information available in the fields of geology and hydrology of the Columbia Plateau was consolidated and two reports were issued summarizing this information. In addition, the information on engineered barriers was consolidated and a report summarizing the research to date on waste package development and design of borehole seals was prepared. The waste package studies, when combined with the hydrologic integration, revealed that even under extreme disruptive conditions, a repository in basalt with appropriately designed waste packages can serve as an excellent barrier for containment of radionuclides for the long periods of time required for waste isolation. On July 1, 1980, the first two heater tests at the Near-Surface Test Facility were started and have been successfully operated to this date. The papers on the Near-Surface Test Facility section of this report present the results of the equipment installed and the preliminary results of the testing. In October 1979, the US Department of Energy selected the joint venture of Kaiser Engineers/Parsons Brinckerhoff Quade and Douglas, Inc., to be the architect-engineer to produce a conceptual design of a repository in basalt. During the year, this design has progressed and concept selection has now been completed. This annual report presents a summary of the highlights of the work completed during fiscal year 1980. It is intended to supplement and summarize the nearly 200 papers and reports that have been distributed to date as a part of the Basalt Waste Isolation Project studies

Natural analogues to the conditions around a final repository for high-level radioactive waste

International Nuclear Information System (INIS)

Smellie, J.A.T.

1984-12-01

This report documents the proceedings resulting from a Workshop held at Lake Geneva, Wisconsin, USA, from 1-3 October, 1984. The theme of the Workshop was entitled 'Natural analogues to the conditions around a final repository for high-level radioactive waste', and was restricted to ultimate disposal in a crystalline bedrock environment. The Workshop provided an important first step in co-ordinating and focussing different national and individual interests and approaches towards natural analogue studies. One of the points highlighted at the concluding forum of the meeting was the necessity to first define the geochemical processes which are assumed to occur after disposal of the radioactive waste, and then locate suitable analogue systems which can be used to test the mechanisms of one, or a simple combination of these geochemical processes. Even accepting that the choice of which geochemical process(es) to be selected for validation will be sensitive to individual national disposal strategies, farfield radionuclide retardation mechanisms in the geosphere were considered to be a central topic of importance, and should therefore be given high priority. At this early stage in the development of natural analogue studies it was not possible to cover all the important aspects. In retrospect, the role of the models should have received more attention; bridging the gap between geoscientists and the modellers was seen as being of prime importance in future meetings of this nature. (author)

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

Geochemical Results of Lysimeter Sampling at the Manning Canyon Repository in the Mercur Mining District, Utah

Science.gov (United States)

Earle, John; Choate, LaDonna

2010-01-01

This report presents chemical characteristics of transient unsaturated-zone water collected by lysimeter from the Manning Canyon repository site in Utah. Data collected by U.S. Geological Survey and U.S. Department of the Interior, Bureau of Land Management scientists under an intragovernmental order comprise the existing body of hydrochemical information on unsaturated-zone conditions at the site and represent the first effort to characterize the chemistry of the soil pore water surrounding the repository. Analyzed samples showed elevated levels of arsenic, barium, chromium, and strontium, which are typical of acidic mine drainage. The range of major-ion concentrations generally showed expected soil values. Although subsequent sampling is necessary to determine long-term effects of the repository, current results provide initial data concerning reactive processes of precipitation on the mine tailings and waste rock stored at the site and provide information on the effectiveness of reclamation operations at the Manning Canyon repository.

Validation of MCNP4A for repository scattered radiation analysis

International Nuclear Information System (INIS)

Haas, M.N.; Su, S.

1998-02-01

Comparison is made between experimentally determined albedo (scattered) radiation and MCNP4A predictions in order to provide independent validation for repository shielding analysis. Both neutron and gamma scattered radiation fields from concrete ducts are compared in this paper. Satisfactory agreement is found between actual and calculated results with conservative values calculated by the MCNP4A code for all conditions

Technical and logistic provisions for the delivery of radioactive wastes in the final repository Konrad

International Nuclear Information System (INIS)

Poeppinghaus, Jens

2013-01-01

The beginning of radioactive waste delivery to the final repository Konrad is planned for 2019. The main issue for the technical and logistic provisions is the development of a concept for the transport of the licensed radioactive waste containers to the site, including a turning concept for cylindrical waste forms and planning, construction and manufacture of transport equipment. Further issues include a logistic concept considering specific boundary conditions as administrative processes, priorities, special features of the delivering institutions and technical requirements of the repository.

The importance of counting cows: Social and economic effects of a high-level nuclear waste repository in Texas

International Nuclear Information System (INIS)

Fleishman, J.; Brody, J.; Galavotti, C.

1987-01-01

Impact assessments that rely on existing records and extrapolation from broad geographic areas provide inadequate information about social and economic conditions important in siting a high-level nuclear waste repository. Texas has used an alternative approach, involving systematic surveys of representative samples of local residents, farm operators and businesses in the proposed site counties and comparison areas. Results show that this technique is useful in describing current economic conditions, including characteristics of key sectors of the economy, changes related to the siting process, and expectations that may influence investment. In addition, the surveys are useful in assessing the degree of consensus in local communities and in identifying possible differential effects of a repository on particular groups. They also provide a baseline for long-term monitoring of repository effects and contribute to their understanding of the underlying processes that shape public response to the nuclear waste program

3D numerical modelling of the thermal state of deep geological nuclear waste repositories

Science.gov (United States)

Butov, R. A.; Drobyshevsky, N. I.; Moiseenko, E. V.; Tokarev, Yu. N.

2017-09-01

One of the important aspects of the high-level radioactive waste (HLW) disposal in deep geological repositories is ensuring the integrity of the engineered barriers which is, among other phenomena, considerably influenced by the thermal loads. As the HLW produce significant amount of heat, the design of the repository should maintain the balance between the cost-effectiveness of the construction and the sufficiency of the safety margins, including those imposed on the thermal conditions of the barriers. The 3D finite-element computer code FENIA was developed as a tool for simulation of thermal processes in deep geological repositories. Further the models for mechanical phenomena and groundwater hydraulics will be added resulting in a fully coupled thermo-hydro-mechanical (THM) solution. The long-term simulations of the thermal state were performed for two possible layouts of the repository. One was based on the proposed project of Russian repository, and another features larger HLW amount within the same space. The obtained results describe the spatial and temporal evolution of the temperature filed inside the repository and in the surrounding rock for 3500 years. These results show that practically all generated heat was ultimately absorbed by the host rock without any significant temperature increase. Still in the short time span even in case of smaller amount of the HLW the temperature maximum exceeds 100 °C, and for larger amount of the HLW the local temperature remains above 100 °C for considerable time. Thus, the substantiation of the long-term stability of the repository would require an extensive study of the materials properties and behaviour in order to remove the excessive conservatism from the simulations and to reduce the uncertainty of the input data.

Gas generation and release from the VLJ repository

International Nuclear Information System (INIS)

Vieno, T.; Valkiainen, M.

1992-01-01

The VLJ repository is an underground disposal facility located at the Olkiluoto nuclear power plant site on the west coast of Finland. The repository will house low (LLW) and intermediate level radioactive wastes (MLW) from the TVO I and TVO II BWR's and the spent fuel interim store at Olkiluoto. The disposal rooms have been excavated at a depth of 60... 100 meters in the crystalline bedrock. They consist of two rock silos - one for the LLW and the other for MLW. Low level waste is usually packed in steel drums and steel boxes. Medium level wastes consists of bituminized resins in steel drums. Wastes packages are emplaced in concrete boxes before transportation into the repository. Low level wastes are emplaced in the shotcreted rock silo where no backfilling will used. For medium level wastes, a separate silo of reinforced concrete has been constructed inside the rock silo. No backfilling will be used inside the concrete silo and an opening will be made in the lid of the concrete silo for gas release. The microbial degradation of low level wastes is the principle gas generation process in the repository. The gas transport though the bedrock covering the repository is evaluated with the help of ground water flow study. It is recommended that the shotcrete lining on the ceiling of the repository cavern is partly removed before the final sealing of the repository. Provided that dissipation of gases from the disposal cavern into the rock can been assured, the overall effects of gas generation on the long-term safety of the repository are insignificant. 10 refs., 6 figs

Design of repository sealing systems - 1981

International Nuclear Information System (INIS)

Ellison, R.D.; Shukla, D.K.; Kelsall, P.C.; D'Appolonia Consulting Engineers, Albuquerque, NM)

1982-01-01

Isolating nuclear waste in geologic repositories will require the sealing of penetrations such as access shafts and tunnels, disposal rooms, and exploration boreholes. This paper discusses seal designs developed for a repository in bedded salt referenced to the stratigraphy of southeastern New Mexico. Designs are based on a multiple component concept whereby individual components are designed for a specific function and location. For a repository in salt the major function of the seals is to exclude groundwater inflow. Two main types of component are included for this purpose: (1) bulk-heads are dense concrete structures keyed into the walls of the penetration and are intended to reduce flow at the interface between the seal and the salt; (2) backfills are granular materials compacted in place in the penetration. In the repository the major backfill material is crushed salt, which is expected to consolidate and recrystallize as the rooms close in response to salt creep. Densely compacted clays will be used as backfill in the shafts closer to potential sources of water inflow. 22 references, 10 figures, 1 table

Creation of Data Repositories to Advance Nursing Science.

Science.gov (United States)

Perazzo, Joseph; Rodriguez, Margaret; Currie, Jackson; Salata, Robert; Webel, Allison R

2017-12-01

Data repositories are a strategy in line with precision medicine and big data initiatives, and are an efficient way to maximize data utility and form collaborative research relationships. Nurse researchers are uniquely positioned to make a valuable contribution using this strategy. The purpose of this article is to present a review of the benefits and challenges associated with developing data repositories, and to describe the process we used to develop and maintain a data repository in HIV research. Systematic planning, data collection, synthesis, and data sharing have enabled us to conduct robust cross-sectional and longitudinal analyses with more than 200 people living with HIV. Our repository building has also led to collaboration and training, both in and out of our organization. We present a pragmatic and affordable way that nurse scientists can build and maintain a data repository, helping us continue to make to our understanding of health phenomena.

Evolution of pH in a radwaste repository: internal reactions between concrete constituents

International Nuclear Information System (INIS)

Atkinson, A.; Everitt, N.M.; Guppy, R.M.

1988-01-01

The pH is an important characteristic of the chemical conditions within a radioactive waste repository. A high pH is particularly beneficial from a variety of points of view and this can be assured by the use of cementitious materials within the repository. Reactions between repository components which have an influence on pH have been studied in accelerated laboratory experiments. The reactions studied were those occurring in modified cements (specifically 90% pulverized fly ash/10% ordinary Portland cement and 90% blast furnace slag/10% OPC) and between aqueous calcium hydroxide and both crystalline and amorphous SiO 2 . The experiments indicate that extensive use of fuel ash leads to uncertainty in long term pH which could be as low as 9 to 10 in such cases. Experiments with crystalline calcium silicon hydrate (CSH) minerals suggest that crystallization of amorphous CSH could also lead to pH being lower than the optimum. (author)

Reducing Psychological Resistance to Digital Repositories

Directory of Open Access Journals (Sweden)

Brian Quinn

2010-06-01

Full Text Available The potential value of digital repositories is dependent on the cooperation of scholars to deposit their work. Although many researchers have been resistant to submitting their work, the literature on digital repositories contains very little research on the psychology of resistance. This article looks at the psychological literature on resistance and explores what its implications might be for reducing the resistance of scholars to submitting their work to digital repositories. Psychologists have devised many potentially useful strategies for reducing resistance that might be used to address the problem; this article examines these strategies and how they might be applied.

Augmenting interoperability across repositories architectural ideas

CERN Multimedia

CERN. Geneva

2005-01-01

The aDORe digital repository architecture designed and implemented by the Los Alamos Research Library is fully standards-based and highly modular, with the various components of the architecture interacting in a protocol-driven manner. Although aDORe was designed for use in the context of the Los Alamos Library, its modular and standards-based design has led to interesting insights regarding possible new levels of interoperability in a federation of heterogeneous repositories. The presentation will discuss these insights, and will illustrate that attractive federations of repositories can be built by introducing rather basic interoperability requirements. The presentation will also show that, once these requirements are met, a powerful service framework that overlays the federation can emerge.