1,332 Matching Results

Search Results

Advanced search parameters have been applied.

Aging and Phase Stability of Waste Package Outer Barrier

Description: This Analysis Model Report (AMR) was prepared in accordance with the Work Direction and Planning Document, ''Aging and Phase Stability of Waste Package Outer Barrier'' (CRWMS M&O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). It takes into consideration the Enhanced Design Alternative II (EDA II), which has been selected as the preferred design for the Engineered Barrier System (EBS) by the License Application Design Selection (LADS) program team (CRWMS M&O 1999b). The salient features of the EDA II design for this model are a waste package (WP) consisting of an outer barrier of Alloy 22 and an inner barrier of Type 316L stainless steel. This report provides information on the phase stability of Alloy 22l, the current waste-package-outer-barrier (WPOB) material. These phase stability studies are currently divided into three general areas: (1) Long-range order reactions; (2) Intermetallic and carbide precipitation in the base metal; and (3) Intermetallic and carbide precipitation in welded samples.
Date: August 23, 2001
Creator: Summers, Tammy S. Edgecumble
Partner: UNT Libraries Government Documents Department

Aging and Phase Stability of Waste Package Outer Barrier

Description: This report was prepared in accordance with ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). This report provides information on the phase stability of Alloy 22, the current waste package outer barrier material. The goal of this model is to determine whether the single-phase solid solution is stable under repository conditions and, if not, how fast other phases may precipitate. The aging and phase stability model, which is based on fundamental thermodynamic and kinetic concepts and principles, will be used to provide predictive insight into the long-term metallurgical stability of Alloy 22 under relevant repository conditions. The results of this model are used by ''General Corrosion and Localized Corrosion of Waste Package Outer Barrier'' as reference-only information. These phase stability studies are currently divided into three general areas: Tetrahedrally close-packed (TCP) phase and carbide precipitation in the base metal; TCP and carbide precipitation in welded samples; and Long-range ordering reactions. TCP-phase and carbide precipitates that form in Alloy 22 are generally rich in chromium (Cr) and/or molybdenum (Mo) (Raghavan et al. 1984 [DIRS 154707]). Because these elements are responsible for the high corrosion resistance of Alloy 22, precipitation of TCP phases and carbides, especially at grain boundaries, can lead to an increased susceptibility to localized corrosion in the alloy. These phases are brittle and also tend to embrittle the alloy (Summers et al. 1999 [DIRS 146915]). They are known to form in Alloy 22 at temperatures greater than approximately 600 C. Whether these phases also form at the lower temperatures expected in the repository during the 10,000-year regulatory period must be determined. The kinetics of this precipitation will be determined for both the base metal and the weld heat-affected zone (HAZ). The TCP phases (P, {mu}, and {sigma}) ...
Date: September 28, 2004
Creator: Wong, F.
Partner: UNT Libraries Government Documents Department

Agricultural and Environmental Input Parameters for the Biosphere Model

Description: This analysis is one of 10 technical reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) (i.e., the biosphere model). It documents development of agricultural and environmental input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for the repository at Yucca Mountain. The ERMYN provides the TSPA with the capability to perform dose assessments. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships between the major activities and their products (the analysis and model reports) that were planned in ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the ERMYN and its input parameters.
Date: September 14, 2004
Creator: Rasmuson, K. & Rautenstrauch, K.
Partner: UNT Libraries Government Documents Department

Analysis of Yucca Mountain Pore-Water Chloride Data

Description: Distribution of chemical constituents in the unsaturated zone (UZ) system of Yucca Mountain, Nevada, depends on many factors, such as hydrological and geochemical processes of surface precipitation, evapotranspiration, the water-fracture-matrix interactions, large-scale mixing via lateral flow and transport, and the history of climate changes. This study analyzes pore-water chloride-concentration data and models the transport processes. The model results are then used to calibrate the UZ flow model with the aim of refining the infiltration distribution and percolation fluxes to the potential repository. The major chemical data used in this study were pore-water chloride (Cl) concentrations. The sensitivity of this conservative tracer to the UZ flow system is well known. This constituent was directly incorporated into a three-dimensional dual-permeability flow model. Chemical transport properties were taken into account. The surface flux of chloride was determined by the total amount of precipitation reaching the surface and chemical concentration in the precipitation. The entire flow system was divided into domains based on the distribution of pore-water chemical data, infiltration data, hydrogeological and hydrostructural features. Model calibration proceeded by adjusting the site-scale infiltration map and anisotropy permeabilities to reach a satisfying agreement between the simulated subsurface chloride distribution and measured data.
Date: June 1, 2001
Creator: Liu, Jianchun; Sonnenthal, Eric & Bodvarrson, Bo
Partner: UNT Libraries Government Documents Department

Biosphere Process Model Report

Description: To evaluate the postclosure performance of a potential monitored geologic repository at Yucca Mountain, a Total System Performance Assessment (TSPA) will be conducted. Nine Process Model Reports (PMRs), including this document, are being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: (1) Integrated Site Model; (2) Unsaturated Zone Flow and Transport; (3) Near Field Environment; (4) Engineered Barrier System Degradation, Flow, and Transport; (5) Waste Package Degradation; (6) Waste Form Degradation; (7) Saturated Zone Flow and Transport; (8) Biosphere; and (9) Disruptive Events. Analysis/Model Reports (AMRs) contain the more detailed technical information used to support TSPA and the PMRs. The AMRs consists of data, analyses, models, software, and supporting documentation that will be used to defend the applicability of each process model for evaluating the postclosure performance of the potential Yucca Mountain repository system. This documentation will ensure the traceability of information from its source through its ultimate use in the TSPA-Site Recommendation (SR) and in the National Environmental Policy Act (NEPA) analysis processes. The objective of the Biosphere PMR is to summarize (1) the development of the biosphere model, and (2) the Biosphere Dose Conversion Factors (BDCFs) developed for use in TSPA. The Biosphere PMR does not present or summarize estimates of potential radiation doses to human receptors. Dose calculations are performed as part of TSPA and will be presented in the TSPA documentation. The biosphere model is a component of the process to evaluate postclosure repository performance and regulatory compliance for a potential monitored geologic repository at Yucca Mountain, Nevada. The biosphere model describes those exposure pathways in the biosphere by which radionuclides released from a potential repository could reach a human receptor. Collectively, the potential human receptor and exposure pathways form the biosphere ...
Date: May 25, 2000
Creator: Schmitt, J.
Partner: UNT Libraries Government Documents Department

Accelerated Testing of the CSNF Waste Form: Applicability to Yucca Mountain

Description: Spent fuel tests in support of Yucca Mountain have been performed for many years. Most of these tests have been either single-pass flowthrough (SPFT) or unsaturated drip tests that have been used to elucidate waste form degradation rates. In general, the tests have been considered accelerated tests per the definition found in ASTM Standard C1174 in that either the temperature or flow rate has been increased in order to increase the rate of alteration. However, as the design and models for the proposed repository have solidified, it is clear that much of what was originally considered an accelerated test is, in reality, either a service condition test or a test that determines bounding conditions that grossly overestimate radionuclide degradation and release rates under repository relevant conditions. This presentation will examine the factors that need to be considered for future waste form, including waste package internals, degradation tests.
Date: January 11, 2005
Creator: Hanson, B.; Buck, E. & Brady, P.
Partner: UNT Libraries Government Documents Department

Automatic Software Processing for Inventories of Nuclides (ASPIN)

Description: EQ6 users have difficulties tracking isotopic concentrations in a system with chemical and nuclear decay reactions. The capability to track isotopic concentrations is particularly important for simulating the degradation of the spent nuclear fuels. Isotopic tracking is necessary to evaluate the criticality risk associated with fissile material relocation inside of a disposal container. A code called ASPRIN (Automatic Software PRocessing, Inventories of Nuclides) was created to allow isotopic tracking using the results of EQ6 simulations.
Date: October 22, 2001
Creator: Gratton, Luca & Rammsy, J.M.
Partner: UNT Libraries Government Documents Department

Bedrock geologic Map of the Central Block Area, Yucca Mountain, Nye County, Nevada

Description: Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. As such, this map focuses on the central block at Yucca Mountain, which contains the potential repository site. The central block is a structural block of Tertiary volcanic rocks bound on the west by the Solitario Canyon Fault, on the east by the Bow Ridge Fault, to the north by the northwest-striking Drill Hole Wash Fault, and on the south by Abandoned Wash. Earlier reconnaissance mapping by Lipman and McKay (1965) provided an overview of the structural setting of Yucca Mountain and formed the foundation for selecting Yucca Mountain as a site for further investigation. They delineated the main block-bounding faults and some of the intrablock faults and outlined the zoned compositional nature of the tuff units that underlie Yucca Mountain. Scott and Bonk (1984) provided a detailed reconnaissance geologic map of favorable area at Yucca Mountain in which to conduct further site-characterization studies. Of their many contributions, they presented a detailed stratigraphy for the volcanic units, defined several other block-bounding faults, and outlined numerous intrablock faults. This study was funded by the U.S. Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bonk (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the ...
Date: September 29, 1998
Creator: Day, W.C.; Potter, C.; Sweetkind, D.; Dickerson, R.P. & Juan, C.A. San
Partner: UNT Libraries Government Documents Department

Calibrated Properties Model

Description: The purpose of this model report is to document the calibrated properties model that provides calibrated property sets for unsaturated zone (UZ) flow and transport process models (UZ models). The calibration of the property sets is performed through inverse modeling. This work followed, and was planned in, ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Sections 1.2.6 and 2.1.1.6). Direct inputs to this model report were derived from the following upstream analysis and model reports: ''Analysis of Hydrologic Properties Data'' (BSC 2004 [DIRS 170038]); ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (BSC 2004 [DIRS 169855]); ''Simulation of Net Infiltration for Present-Day and Potential Future Climates'' (BSC 2004 [DIRS 170007]); ''Geologic Framework Model'' (GFM2000) (BSC 2004 [DIRS 170029]). Additionally, this model report incorporates errata of the previous version and closure of the Key Technical Issue agreement TSPAI 3.26 (Section 6.2.2 and Appendix B), and it is revised for improved transparency.
Date: October 4, 2004
Creator: Ghezzehej, T.
Partner: UNT Libraries Government Documents Department

Calibrated Properties Model

Description: The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the ''AMR Development Plan for U0035 Calibrated Properties Model REV00. These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.
Date: March 12, 2000
Creator: Ahlers, C. & Liu, H.
Partner: UNT Libraries Government Documents Department

Building and Running the Yucca Mountain Total System Performance Model in a Quality Environment

Description: A Total System Performance Assessment (TSPA) model has been developed to support the Safety Analysis Report (SAR) for the Yucca Mountain High-Level Waste Repository. The TSPA model forecasts repository performance over a 20,000-year simulation period. It has a high degree of complexity due to the complexity of its underlying process and abstraction models. This is reflected in the size of the model (a 27,000 element GoldSim file), its use of dynamic-linked libraries (14 DLLs), the number and size of its input files (659 files totaling 4.7 GB), and the number of model input parameters (2541 input database entries). TSPA model development and subsequent simulations with the final version of the model were performed to a set of Quality Assurance (QA) procedures. Due to the complexity of the model, comments on previous TSPAs, and the number of analysts involved (22 analysts in seven cities across four time zones), additional controls for the entire life-cycle of the TSPA model, including management, physical, model change, and input controls were developed and documented. These controls did not replace the QA. procedures, rather they provided guidance for implementing the requirements of the QA procedures with the specific intent of ensuring that the model development process and the simulations performed with the final version of the model had sufficient checking, traceability, and transparency. Management controls were developed to ensure that only management-approved changes were implemented into the TSPA model and that only management-approved model runs were performed. Physical controls were developed to track the use of prototype software and preliminary input files, and to ensure that only qualified software and inputs were used in the final version of the TSPA model. In addition, a system was developed to name, file, and track development versions of the TSPA model as well as simulations performed with the final ...
Date: January 9, 2005
Creator: Kalinich, D.A.; Lee, K.P. & McNeish, J.A.
Partner: UNT Libraries Government Documents Department

Calibrated Properties Model

Description: This report has documented the methodologies and the data used for developing rock property sets for three infiltration maps. Model calibration is necessary to obtain parameter values appropriate for the scale of the process being modeled. Although some hydrogeologic property data (prior information) are available, these data cannot be directly used to predict flow and transport processes because they were measured on scales smaller than those characterizing property distributions in models used for the prediction. Since model calibrations were done directly on the scales of interest, the upscaling issue was automatically considered. On the other hand, joint use of data and the prior information in inversions can further increase the reliability of the developed parameters compared with those for the prior information. Rock parameter sets were developed for both the mountain and drift scales because of the scale-dependent behavior of fracture permeability. Note that these parameter sets, except those for faults, were determined using the 1-D simulations. Therefore, they cannot be directly used for modeling lateral flow because of perched water in the unsaturated zone (UZ) of Yucca Mountain. Further calibration may be needed for two- and three-dimensional modeling studies. As discussed above in Section 6.4, uncertainties for these calibrated properties are difficult to accurately determine, because of the inaccuracy of simplified methods for this complex problem or the extremely large computational expense of more rigorous methods. One estimate of uncertainty that may be useful to investigators using these properties is the uncertainty used for the prior information. In most cases, the inversions did not change the properties very much with respect to the prior information. The Output DTNs (including the input and output files for all runs) from this study are given in Section 9.4.
Date: February 14, 2003
Creator: Liu, H. H.
Partner: UNT Libraries Government Documents Department

Calibration of the Site-Scale Saturated Zone Flow Model

Description: The purpose of the flow calibration analysis work is to provide Performance Assessment (PA) with the calibrated site-scale saturated zone (SZ) flow model that will be used to make radionuclide transport calculations. As such, it is one of the most important models developed in the Yucca Mountain project. This model will be a culmination of much of our knowledge of the SZ flow system. The objective of this study is to provide a defensible site-scale SZ flow and transport model that can be used for assessing total system performance. A defensible model would include geologic and hydrologic data that are used to form the hydrogeologic framework model; also, it would include hydrochemical information to infer transport pathways, in-situ permeability measurements, and water level and head measurements. In addition, the model should include information on major model sensitivities. Especially important are those that affect calibration, the direction of transport pathways, and travel times. Finally, if warranted, alternative calibrations representing different conceptual models should be included. To obtain a defensible model, all available data should be used (or at least considered) to obtain a calibrated model. The site-scale SZ model was calibrated using measured and model-generated water levels and hydraulic head data, specific discharge calculations, and flux comparisons along several of the boundaries. Model validity was established by comparing model-generated permeabilities with the permeability data from field and laboratory tests; by comparing fluid pathlines obtained from the SZ flow model with those inferred from hydrochemical data; and by comparing the upward gradient generated with the model with that observed in the field. This analysis is governed by the Office of Civilian Radioactive Waste Management (OCRWM) Analysis and Modeling Report (AMR) Development Plan ''Calibration of the Site-Scale Saturated Zone Flow Model'' (CRWMS M&O 1999a).
Date: June 28, 2001
Creator: Zyvoloski, G. A.
Partner: UNT Libraries Government Documents Department

Calibrated Properties Model

Description: The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the AMR Development Plan for U0035 Calibrated Properties Model REV00 (CRWMS M&O 1999c). These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.
Date: December 18, 2001
Creator: C.F. Ahlers, H.H. Liu
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes: Disruptive Events

Description: The primary purpose of this analysis is to evaluate seismic- and igneous-related features, events, and processes (FEPs). These FEPs represent areas of natural system processes that have the potential to produce disruptive events (DE) that could impact repository performance and are related to the geologic processes of tectonism, structural deformation, seismicity, and igneous activity. Collectively, they are referred to as the DE FEPs. This evaluation determines which of the DE FEPs are excluded from modeling used to support the total system performance assessment for license application (TSPA-LA). The evaluation is based on the data and results presented in supporting analysis reports, model reports, technical information, or corroborative documents that are cited in the individual FEP discussions in Section 6.2 of this analysis report.
Date: March 31, 2004
Creator: King, J.
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes: Disruptive Events

Description: The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the disruptive events features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment for license application (TSPA-LA). A screening decision, either ''Included'' or ''Excluded,'' is given for each FEP, along with the technical basis for screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d), (e), and (f) [DIRS 156605]. The FEPs addressed in this report deal with both seismic and igneous disruptive events, such as fault displacements through the repository and an igneous intrusion into the repository. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). Previous versions of this report were developed to support the total system performance assessments (TSPA) for various prior repository designs. This revision addresses the repository design for the license application (LA).
Date: November 8, 2004
Creator: Sanchez, P.
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes in SZ Flow and Transport

Description: This analysis report evaluates and documents the inclusion or exclusion of the saturated zone (SZ) features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment (TSPA) for license application (LA) of a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either ''Included'' or ''Excluded'', is given for each FEP along with the technical basis for the decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d), (e), (f) (DIRS 156605). This scientific report focuses on FEP analysis of flow and transport issues relevant to the SZ (e.g., fracture flow in volcanic units, anisotropy, radionuclide transport on colloids, etc.) to be considered in the TSPA model for the LA. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded).
Date: November 16, 2004
Creator: Economy, K.
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes in UZ Flow and Transport

Description: The evaluation of impacts of potential volcanic eruptions on populations and facilities far in the future may involve detailed volcanological studies that differ from traditional hazards analyses. The proximity of Quaternary volcanoes to a proposed repository for disposal of the USA's high-level radioactive waste at Yucca Mountain, Nevada, has required in-depth study of probability and consequences of basaltic igneous activity. Because of the underground nature of the repository, evaluation of the potential effects of dike intrusion and interaction with the waste packages stored in underground tunnels (dnfts) as well as effects of eruption and ash dispersal have been important. These studies include analyses of dike propagation, dike-drift intersection, flow of magma into dnfts, heat and volcanic gas migration, atmospheric dispersal of tephra, and redistribution of waste-contaminated tephra by surficial processes. Unlike traditional volcanic hazards studies that focus on impacts on housing, transportation, communications, etc. (to name a small subset), the igneous consequences studies at Yucca Mountain have focused on evaluation of igneous impacts on nuclear waste packages and implications for enhanced radioactive dose on a hypothetical future ({le} 10000 yrs) local population. Potential exposure pathways include groundwater (affected by in-situ degradation of waste packages by igneous heat and corrosion) and inhalation, ingestion, and external exposure due to deposition and redistribution of waste-contaminated tephra.
Date: November 6, 2004
Creator: Persoff, P.
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes in UZ and Transport

Description: The purpose of this report is to evaluate and document the inclusion or exclusion of the unsaturated zone (UZ) features, events, and processes (FEPs) with respect to modeling that supports the total system performance assessment (TSPA) for license application (LA) for a nuclear waste repository at Yucca Mountain, Nevada. A screening decision, either ''Included'' or ''Excluded'', is given for each FEP, along with the technical basis for the screening decision. This information is required by the U.S. Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs deal with UZ flow and radionuclide transport, including climate, surface water infiltration, percolation, drift seepage, and thermally coupled processes. This analysis summarizes the implementation of each FEP in TSPA-LA (that is, how the FEP is included) and also provides the technical basis for exclusion from TSPA-LA (that is, why the FEP is excluded). This report supports TSPA-LA.
Date: November 6, 2004
Creator: Persoff, P.
Partner: UNT Libraries Government Documents Department

Features, Events, and Processes in UZ Flow and Transport

Description: Unsaturated zone (UZ) flow and radionuclide transport is a component of the natural barriers that affects potential repository performance. The total system performance assessment (TSPA) model, and underlying process models, of this natural barrier component capture some, but not all, of the associated features, events, and processes (FEPs) as identified in the FEPs Database (Freeze, et al. 2001 [154365]). This analysis and model report (AMR) discusses all FEPs identified as associated with UZ flow and radionuclide transport. The purpose of this analysis is to give a comprehensive summary of all UZ flow and radionuclide transport FEPs and their treatment in, or exclusion from, TSPA models. The scope of this analysis is to provide a summary of the FEPs associated with the UZ flow and radionuclide transport and to provide a reference roadmap to other documentation where detailed discussions of these FEPs, treated explicitly in TSPA models, are offered. Other FEPs may be screened out from treatment in TSPA by direct regulatory exclusion or through arguments concerning low probability and/or low consequence of the FEPs on potential repository performance. Arguments for exclusion of FEPs are presented in this analysis. Exclusion of specific FEPs from the UZ flow and transport models does not necessarily imply that the FEP is excluded from the TSPA. Similarly, in the treatment of included FEPs, only the way in which the FEPs are included in the UZ flow and transport models is discussed in this document. This report has been prepared in accordance with the technical work plan for the unsaturated zone subproduct element (CRWMS M&O 2000 [153447]). The purpose of this report is to document that all FEPs are either included in UZ flow and transport models for TSPA, or can be excluded from UZ flow and transport models for TSPA on the basis of low ...
Date: April 10, 2001
Creator: Houseworth, J.E.
Partner: UNT Libraries Government Documents Department

FEPs Screening of Processes and Issues in Drip Shield and Waste Package Degradation

Description: The purpose of this report is to evaluate and document the inclusion or exclusion of features, events and processes (FEPs) with respect to drip shield and waste package modeling used to support the Total System Performance Assessment for License Application (TSPA-LA). Thirty-three FEPs associated with the waste package and drip shield performance have been identified (DTN: MO0407SEPFEPLA.000 [DIRS 170760]). A screening decision, either ''included'' or ''excluded,'' has been assigned to each FEP, with the technical bases for screening decisions, as required by the Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs analyses in this report address issues related to the degradation and potential failure of the drip shield and waste package over the post closure regulatory period of 10,000 years after permanent closure. For included FEPs, this report summarizes the disposition of the FEP in TSPA-LA. For excluded FEPs, this report provides the technical bases for the screening arguments for exclusion from TSPA-LA. The analyses are for the TSPA-LA base-case design (BSC 2004 [DIRS 168489]), where a drip shield is placed over the waste package without backfill over the drip shield (BSC 2004 [DIRS 168489]). Each FEP includes one or more specific issues, collectively described by a FEP name and description. The FEP description encompasses a single feature, event, or process, or a few closely related or coupled processes, provided the entire FEP can be addressed by a single specific screening argument or TSPA-LA disposition. The FEPs were assigned to associated Project reports, so the screening decisions reside with the relevant subject-matter experts.
Date: October 11, 2004
Creator: Mon, K.
Partner: UNT Libraries Government Documents Department