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An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses-Criticality (keff) Predictions
An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses-Criticality (keff) Predictions
Taking credit for the reduced reactivity of spent nuclear fuel (SNF) in criticality analyses is referred to as burnup credit (BUC). Criticality safety evaluations require validation of the computational methods with critical experiments that are as similar as possible to the safety analysis models, and for which the keff values are known. This poses a challenge for validation of BUC criticality analyses, as critical experiments with actinide and fission product (FP)
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
Summary Report of Commercial Reactor Criticality Data for Crystal River Unit 3
Summary Report of Commercial Reactor Criticality Data for Crystal River Unit 3
The "Summary Report of Commercial Reactor Criticality Data for Crystal River Unit 3" contains the detailed information necessary to perform commercial reactor criticality (CRC) analyses for the Crystal River Unit 3 (CR3) reactor.
Fission Product Benchmarking for Burnup Credit Applications
Fission Product Benchmarking for Burnup Credit Applications
Progress toward developing a technical basis for a cost-effective burnup credit methodology for
spent nuclear fuel with initial U-235 enrichment up to 5% is presented. Present regulatory
practices provide as much burnup credit flexibility as can be currently expected. Further progress
is achievable by incorporating the negative reactivity effects of a subset of neutron-absorbing
fission product isotopes. Progress also depends on optimizing the procedure for establishing the
Safety Evaluation Report for Disposal Criticality Analysis Methodology Topical Report, Revision 0
Safety Evaluation Report for Disposal Criticality Analysis Methodology Topical Report, Revision 0
In January 1999, the U.S. Department of Energy (DOE)/Office of Civilian Radioactive
Waste Management (OCRWM) submitted the Disposal Criticality Analysis Methodology
Topical Report, Revision 0 (TR) to the U.S. Nuclear Regulatory Commission (NRC) for
review and approval. The TR presents an overall approach for consideration of postclosure
disposal criticality of commercial and defense high-level waste to be placed at
the proposed Yucca Mountain site. During the course of the review and interactions
ANSI/ANS-8.27-2008: Burnup Credit for LWR Fuel
ANSI/ANS-8.27-2008: Burnup Credit for LWR Fuel
This standard provides criteria for accounting for reactivity effects of fuel irradiation and radioactive decay in criticality safety control of storage, transportation, and disposal of commercial LWR UO2 fuel assemblies.
This standard assumes the fuel and any fixed burnable absorbers are contained in an intact assembly. Additional considerations could be necessary for fuel assemblies that have been disassembled, consolidated, damaged, or reconfigured in any manner.
Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask
Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask
The Interim Staff Guidance on burnup credit (ISG-8) for spent fuel in storage and transportation casks, issued by the Nuclear Regulatory Commission’s Spent Fuel Project Office, recommends a burnup measurement for each assembly to confirm the reactor record and compliance with the assembly burnup value used for loading acceptance. This recommendation is intended to prevent unauthorized loading (misloading) of assemblies due to inaccuracies in reactor burnup records and/or improper assembly identification, thereby ensuring that the appropriate subcritical margin is maintained.
OECD/NEA Burnup Credit Criticality Benchmark, Analysis of Phase II-B Results: Conceptual PWR Spent Fuel Transportation Cask
OECD/NEA Burnup Credit Criticality Benchmark, Analysis of Phase II-B Results: Conceptual PWR Spent Fuel Transportation Cask
Experimental Investigation of Burnup Credit for Safe Transport, Storage, and Disposal of Spent Nuclear Fuel
Experimental Investigation of Burnup Credit for Safe Transport, Storage, and Disposal of Spent Nuclear Fuel
Burnup Credit - Technical Basis for Spent-Fuel Burnup Verification
Burnup Credit - Technical Basis for Spent-Fuel Burnup Verification
Present regulatory practices provide as much burnup credit flexibility as can be currently
expected. Further progress is achievable by incorporating the negative reactivity effects of a
subset of neutron-absorbing fission-product isotopes, and by optimizing the procedural approach
for establishing the burnup characteristics of the spent fuel to be loaded in burnup-creditdesigned
storage and transportation systems. This report describes progress toward developing a
BWR Axial Profile
BWR Axial Profile
Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty
Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty
Analytical methods, described in this report, are used to
systematically determine experimental fuel sub-batch
reactivities as a function of burnup. Fuel sub-batch reactivities
are inferred using more than 600 in-core pressurized water
reactor (PWR) flux maps taken during 44 cycles of operation
at the Catawba and McGuire nuclear power plants. The
analytical methods systematically search for fuel sub-batch
reactivities that minimize differences between measured and
computed reaction rates, using Studsvik Scandpower’s
Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation
Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation
Pressurized water reactor (PWR) burnup credit validation is
demonstrated using the benchmarks for quantifying fuel reactivity
decrements, published as Benchmarks for Quantifying Fuel Reactivity
Depletion Uncertainty, Electric Power Research Institute (EPRI)
report 1022909. This demonstration uses the depletion module
TRITON (Transport Rigor Implemented with Time-Dependent
Operation for Neutronic Depletion) available in the SCALE 6.1
(Standardized Computer Analyses for Licensing Evaluations) code
Feasibility of Direct Disposal of Dual-Purpose Canisters-Options for Assuring Criticality Control
Feasibility of Direct Disposal of Dual-Purpose Canisters-Options for Assuring Criticality Control
The concept of direct disposal of dual-purpose canisters (DPCs) has not been previously considered
for the Yucca Mountain geologic repository because of concerns, among other reasons,
about degradation of the reactivity-control material over the relatively long period of the repository
analyses. Aluminum-based neutron absorber materials, typically used in DPCs, are not
expected to have sufficient corrosion resistance necessary to retain their integrity over a 10,000+
Topical Report on Actinide-Only Burnup Credit for PWR Spent Nuclear Fuel Packages
Topical Report on Actinide-Only Burnup Credit for PWR Spent Nuclear Fuel Packages
A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay.
Burn-up Credit Criticality Safety Benchmark - Phase VII, UO2 Fuel: Study of Spent Fuel Compositions for Long-term Disposal
Burn-up Credit Criticality Safety Benchmark - Phase VII, UO2 Fuel: Study of Spent Fuel Compositions for Long-term Disposal
Analysis of Experimental Data for High Burnup PWR Spent Fuel Isotopic Validation--Calvert Cliffs, Takahama, and Three Mile Island Reactors
Analysis of Experimental Data for High Burnup PWR Spent Fuel Isotopic Validation--Calvert Cliffs, Takahama, and Three Mile Island Reactors
This report is part of a report series designed to document benchmark-quality radiochemical isotopic
assay data against which computer code accuracy can be quantified to establish the uncertainty and bias
associated with the code predictions. The experimental data included in the report series were acquired
from domestic and international programs and include spent fuel samples that cover a large burnup range.
The measurements analyzed in the current report, for which experimental data is publicly available,
Topical Report on Actinide-Only Burnup Credit for PWR Spent Nuclear Fuel Packages
Topical Report on Actinide-Only Burnup Credit for PWR Spent Nuclear Fuel Packages
A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay.
The Likelihood of Criticality Following Disposal of SF/HLW/HEU/Pu
The Likelihood of Criticality Following Disposal of SF/HLW/HEU/Pu
PWR Axial Burnup Profile Analysis
PWR Axial Burnup Profile Analysis
Burn-up Credit Criticality Safety Benchmark - Phase VII, UO2 Fuel: Study of Spent Fuel Compositions for Long-term Disposal
Burn-up Credit Criticality Safety Benchmark - Phase VII, UO2 Fuel: Study of Spent Fuel Compositions for Long-term Disposal
Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask
Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask
The Interim Staff Guidance on burnup credit (ISG-8) for spent fuel in storage and transportation casks, issued by the Nuclear Regulatory Commission’s Spent Fuel Project Office, recommends a burnup measurement for each assembly to confirm the reactor record and compliance with the assembly burnup value used for loading acceptance. This recommendation is intended to prevent unauthorized loading (misloading) of assemblies due to inaccuracies in reactor burnup records and/or improper assembly identification, thereby ensuring that the appropriate subcritical margin is maintained.