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SAS2H Generated Isotopic Concentrations for B&W 15xl5 PWR Assembly (SCPB: N/A)
SAS2H Generated Isotopic Concentrations for B&W 15xl5 PWR Assembly (SCPB: N/A)
This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide pressurized water reactor (PWR) isotopic composition data as a function of time for use in criticality analyses. The objectives of this evaluation are to generate burnup and decay dependant isotopic inventories and to provide these inventories in a form which can easily be utilized in subsequent criticality calculations.
Report On External Criticality of Plutonium Waste Forms In A Geologic Repository
Report On External Criticality of Plutonium Waste Forms In A Geologic Repository
This report presents the analyses and results for the potential occurrence of external criticality events which could result from plutonium waste forms emplaced in a geologic repository similar to the one being developed at Yucca Mountain. The analyses evaluate both the MOX spent fuel and the immobilized plutonium waste forms in a repository if the waste package has degraded and if the fissile material has migrated to the invert and out into the far-field.
Initial Radionuclide Inventories
Initial Radionuclide Inventories
The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only.
Spent Fuel Project Office, Interim Staff Guidance - 8, Revision 1, Burnup Credit in the Criticality Safety Analyses of PWR Spent Fuel in Transport and Storage Casks
Spent Fuel Project Office, Interim Staff Guidance - 8, Revision 1, Burnup Credit in the Criticality Safety Analyses of PWR Spent Fuel in Transport and Storage Casks
Spent Fuel Project Office, Interim Staff Guidance - 8, Revision 1
Transportation System Requirements Document Revision 5
Transportation System Requirements Document Revision 5
The Nuclear Waste Policy Act of 1982 (NWPA), as amended, authorized the DOE to develop and manage a Federal system for the disposal of Spent Nuclear Fuel (SNF) and High-Level Radioactive Waste (HLW). The Office of Civilian Radioactive Waste (OCRWM) was created to manage acceptance, transportation and disposal of SNF and HLW in a manner that protects public health, safety, and the environment; enhances national and energy security; and merits public confidence.
SCALE-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 1-Summary
SCALE-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 1-Summary
The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor
criticality safety analyses be validated against experimental measurements. If credit is to be taken for
the reduced reactivity of burned or spent fuel relative to its original $fresh# composition, it is
necessary to benchmark computational methods used in determining such reactivity worth against
spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to
OECD/NEA Burnup Credit Criticality Benchmarks Phase IIIB: Burnup Calculations of BWR Fuel Assemblies for Storage and Transport
OECD/NEA Burnup Credit Criticality Benchmarks Phase IIIB: Burnup Calculations of BWR Fuel Assemblies for Storage and Transport
The report describes the final results of the Phase IIIB Benchmark conducted by the
Expert Group on Burnup Credit Criticality Safety under the auspices of the Nuclear Energy
Agency (NEA) of the Organization for Economic Cooperation and Development (OECD).
The Benchmark was intended to compare the predictability of current computer code and
data library combinations for the atomic number densities of an irradiated BWR fuel
assembly model. The fuel assembly was irradiated under specific power of 25.6 MW/tHM
ANS Position Statement: Licensing of Yucca Mountain as a Geological Repository for Radioactive Wastes
ANS Position Statement: Licensing of Yucca Mountain as a Geological Repository for Radioactive Wastes
The American Nuclear Society (ANS) supports (1) the development and use of geological
repositories for disposal of high-level radioactive wastes and (2) expeditious processing of the
Yucca Mountain license application in an open, technically sound manner. Geological disposal
means placing the wastes hundreds of feet underground and far from the biosphere. The U.S.
Nuclear Regulatory Commission (NRC) is following a legislatively well-defined regulatory
process to evaluate the safety of the proposed Yucca Mountain Site to meet both the scientific
Public Beliefs, Concerns and Preferences Regarding the Management of Used Nuclear Fuel and High Level Radioactive Waste
Public Beliefs, Concerns and Preferences Regarding the Management of Used Nuclear Fuel and High Level Radioactive Waste
US policy for management of used nuclear fuel (UNF) and high level radioactive wastes (HLRW) is at a crossroads, and the success of new policy directions will depend in part on broad public acceptance and support. In this paper I provide an overview of the evidence concerning the beliefs and concerns of members of the American public regarding UNF and HLNW. I also characterize the evidence on American’s policy preferences for management of these materials.
Evaluation of Measured LWR Spent Fuel Composition Data for Use in Code Validation End-User Manual
Evaluation of Measured LWR Spent Fuel Composition Data for Use in Code Validation End-User Manual
Burnup credit (BUC) is a concept applied in the criticality safety analysis of spent nuclear fuel
in which credit or partial credit is taken for the reduced reactivity worth of the fuel due to both fissile
depletion and the buildup of actinides and fission products that act as net neutron absorbers.
Typically, a two-step process is applied in BUC analysis: first, depletion calculations are performed
to estimate the isotopic content of spent fuel based on its burnup history; second, three-dimensional
Probabilistic Criticality Consequence Evaluation
Probabilistic Criticality Consequence Evaluation
This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development (WPD) department with the objective of providing a comprehensive, conservative estimate of the consequences of the criticality which could possibly occur as the result of commercial spent nuclear fuel emplaced in the underground repository at Yucca Mountain. The consequences of criticality are measured principally in terms of the resulting changes in radionuclide inventory as a function of the power level and duration of the criticality.
Key Issues Associated with Interim Storage of Used Nuclear Fuel
Key Issues Associated with Interim Storage of Used Nuclear Fuel
The issue of interim storage of used (spent)1 fuel is dependent on a number of key factors, some
of which are not known at this time but are the subject of this study. The first is whether or not
the Yucca Mountain Project continues or is cancelled such that it may be able to receive spent
fuel from existing and decommissioned nuclear power stations. The second is whether the United
States will pursue a policy of reprocessing and recycling nuclear fuel. The reprocessing and
Drift-Scale THC Seepage Model
Drift-Scale THC Seepage Model
The purpose of this report is to document the thermal-hydrologic-chemical (THC) seepage model and model simulations. The simulations predict the composition of fracture water that could potentially seep into repository emplacement drifts and the composition of the associated gas phase. The THC seepage model is not used to feed the total system performance assessment (TSPA) for the license application (LA).
THC Sensitivity Study of Heterogeneous Permeability and Capillarity Effects
THC Sensitivity Study of Heterogeneous Permeability and Capillarity Effects
The purpose of this report is to <,locument the sensitivity of the drift-scale thermal-hydrologic- chemical (THC) seepage model (SNL 2007 [DIRS 177404]) to heterogeneities in permeability and capillarity, which could affect predicted fluxes and chemistries of water and gases seeping into the emplacement drifts. This report has been developed following Technical Work Plan for: Revision of Model Reports for Near-Field and In-Drift Water Chemistry (SNL 2007 [DIRS 179287]).
Investigation of Burnup Credit Modeling Issues Associated with BWR Fuel
Investigation of Burnup Credit Modeling Issues Associated with BWR Fuel
This report investigates various calculational modeling issues associated with boilingwater-
reactor (BWR) fuel depletion relevant to burnup credit. To date, most of the efforts in
burnup-credit studies in the United States have focused on issues related to pressurized-waterreactor
(PWR) fuel. However, requirements for the permanent disposal of BWR fuel have
necessitated the development of methods for predicting the spent fuel contents for such fuels.
Concomitant with such analyses, validation is also necessary. This report provides a summary of
Internationalization of the Nuclear Fuel Cycle
Internationalization of the Nuclear Fuel Cycle
Following the proposals for nuclear fuel assurance of International Atomic Energy
Agency (IAEA) Director General Mohamed El Baradei, former Russian President Vladimir V.
Putin, and U.S. President George W. Bush, joint committees of the Russian Academy of
Sciences (RAS) and the U.S. National Academies (NAS) were formed to address these and other
fuel assurance concepts and their links to nonproliferation goals. The joint committees also
addressed many technology issues relating to the fuel assurance concepts. This report provides
Direct Disposal of Dual-Purpose Canisters - Options for Assuring Criticality Control
Direct Disposal of Dual-Purpose Canisters - Options for Assuring Criticality Control
Nuclear Criticality Calculations for Canister-Based Facilities - DOE SNF
Nuclear Criticality Calculations for Canister-Based Facilities - DOE SNF
The purpose of this calculation is to perform waste-form specific nuclear criticality safety calculations to aid in establishing criticality safety design criteria, and to identify design and process parameters that are potentially important to the criticality safety of Department of Energy (DOE) standardized Spent Nuclear Fuel (SNF) canisters.
Degraded Waste Package Criticality: Summary Report of Evaluations Through 1996
Degraded Waste Package Criticality: Summary Report of Evaluations Through 1996
The purpose of this document is to summarize the degraded waste package disposal criticality evaluations which were performed in fiscal years I995 and I996. These evaluations were described in detail in 4 previous documents (Refs. I through 4). The initial version of this summary has been described in the I996 Disposal Criticality Analysis Methodology Technical Report (Ref. 5). A topical report planned for 1998 will present the methodology in its final form for approval by the US Nuclear Regulatory Commission.
An Extension of the Validation of SCALE (SAS2H) Isotopic Predictions of PWR Spent Fuel
An Extension of the Validation of SCALE (SAS2H) Isotopic Predictions of PWR Spent Fuel
Isotopic characterization of spent fuel via depletion and decay calculations is necessary for
determination of source terms for subsequent system analyses involving heat transfer, radiation
shielding, isotopic migration, etc. Unlike fresh fuel assumptions typically employed in the criticality
safety analysis of spent fuel configurations, burnup credit applications also rely on depletion and
decay calculations to predict the isotopic composition of spent fuel. These isotopics are used in
Calculation of Upper Subcritical Limits for Nuclear Criticality in a Repository
Calculation of Upper Subcritical Limits for Nuclear Criticality in a Repository
The purpose of this document is to present the methodology to be used for development of the Subcritical Limit (SL) for post closure conditions for the Yucca Mountain repository. The SL is a value based on a set of benchmark criticality multiplier, keff> results that are outputs of the MCNP calculation method. This SL accounts for calculational biases and associated uncertainties resulting from the use of MCNP as the method of assessing kerr·
Management of Commercial High Level and Transuranium Contaminated Radioactive Waste
Management of Commercial High Level and Transuranium Contaminated Radioactive Waste
This report summarizes the results of EPA's review of the AEC
draft environmental statement, "Management of Commercial High-Level
and Transuranium-Contaminated Radioactive Waste" (WASH-1539). The
means by which high-level and long-lived radioactive wastes are
managed constitutes one of the most important questions upon which
the public acceptability of nuclear power, with its social and economic
benefits, will be determined. While the generation of power by
nuclear means offers certain benefits from the environmental viewpoint,
SAS2H Analysis of Radiochemical Assay Samples from Obrigheim PWR Reactor
SAS2H Analysis of Radiochemical Assay Samples from Obrigheim PWR Reactor
The purpose of this design analysis is to determine the accuracy of the SAS2H module of SCALE 4.3 in predicting isotopic concentrations of spent fuel assemblies. The objective is to develop a methodology for modeling assemblies similar to those evaluated within this analysis and to establish the consistency of SAS2H predictions. The results of this analysis may then be applied to future depletion calculations using SAS2H in which no measurements are available.
Criticality Evaluation of Intact and Degraded PWR WPs Containing MOX SNF
Criticality Evaluation of Intact and Degraded PWR WPs Containing MOX SNF
The purpose of this calculation is to perform criticality evaluations for mixed oxide spent nuclear fuel in 12 and 21 pressurized water reactor waste packages for both intact and degraded configurations. The MOX assembly design considered in previous studies on Pu disposition in commercial reactors is based on the Westinghouse 17x17 Vantage 5 assembly (Ref. 7.2). Depletion analyses of four Pu enrichment and burnup(expressed as gigawatt days/metric ton heavy metal; GWd/MTHM)) combinations were performed in Ref. 7.4.