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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
Translation of Technical Development on Burn-Up Credit for Spent LWR Fuels
Translation of Technical Development on Burn-Up Credit for Spent LWR Fuels
Technical development on burn-up credit for spent LWR fuels had been performed at JAERI since
1990 under the contract with Science and Technology Agency of Japan entitled ‘Technical Development on
Criticality Safety Management for Spent LWR Fuels.’ Main purposes of this work are to obtain the
experimental data on criticality properties and isotopic compositions of spent LWR fuels and to verify burnup
and criticality calculation codes. In this work three major experiments of exponential experiments for
UCF Waste Package Criticality Analysis
UCF Waste Package Criticality Analysis
This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to determine the viability of the UCF waste package concept with respect to criticality regulatory requirements in compliance with the goals of the Waste Package Implementation Plan5·1 for conceptual design. These design calculations are performed in sufficient detail to provide a comprehensive comparison base with other design alternatives.
A Stochastic Method for Estimating the Effect of Isotopic Uncertainties in Spent Nuclear Fuel
A Stochastic Method for Estimating the Effect of Isotopic Uncertainties in Spent Nuclear Fuel
This report describes a novel approach developed at the Oak Ridge National Laboratory
(ORNL) for the estimation of the uncertainty in the prediction of the neutron multiplication factor
for spent nuclear fuel. This technique focuses on burnup credit, where credit is taken in criticality
safety analysis for the reduced reactivity of fuel irradiated in and discharged from a reactor.
Validation methods for burnup credit have attempted to separate the uncertainty associated with
Prediction of the Isotopic Composition of UO2 Fuel from a BWR: Analysis of the DU1 Sample from the Dodewaard Reactor
Prediction of the Isotopic Composition of UO2 Fuel from a BWR: Analysis of the DU1 Sample from the Dodewaard Reactor
As part of a larger program to study mixed-oxide fuel subject to high burnup, some UO2 samples were exposed and analyzed. This report discusses results from the analysis of a UO sample that was burned in a boiling-water reactor (BWR) to approximately 57 GWd/t. The sample
Isotopic Models for Commercial SNF Burnup Credit
Isotopic Models for Commercial SNF Burnup Credit
Disposal Criticality Analysis Methodology Topical Report1 describes a methodology for performing postclosure criticality analyses within the repository at Yucca Mountain, Nevada. An important component of the postclosure criticality analysis is the calculation of conservative isotopic concentrations for spent nuclear fuel. This report documents the isotopic calculation methodology. The isotopic calculation methodology is shown to be conservative based upon current data for pressurized water reactor and boiling water reactor spent nuclear fuel.
U.S. Regulatory Recommendations for Actinide-Only Burnup Credit in Transport and Storage Casks
U.S. Regulatory Recommendations for Actinide-Only Burnup Credit in Transport and Storage Casks
In July 1999, the U.S. Nuclear Regulatory Commission (NRC) Spent Fuel Project Office
(SFPO) issued Interim Staff Guidance 8 Revision 1 (ISG8R1) to provide recommendations for the use
of burnup credit in storage and transport of pressurized-water reactor (PWR) spent fuel. Subsequent to
the issuance of ISG8R1, the NRC Office of Regulatory Research (RES) has directed an effort to
investigate the technical basis for extending the criteria and recommendations of ISG8R1 to allow
Parametric Analysis of PWR Spent Fuel Depletion Parameters for Long-Term Disposal Criticality Safety
Parametric Analysis of PWR Spent Fuel Depletion Parameters for Long-Term Disposal Criticality Safety
Utilization of burnup credit in criticality safety analysis for long-term disposal of spent
nuclear fuel allows improved design efficiency and reduced cost due to the large mass of fissile
material that will be present in the repository. Burnup-credit calculations are based on depletion
calculations that provide a conservative estimate of spent fuel contents (in terms of criticality
potential), followed by criticality calculations to assess the value of the effective neutron
44-BWR WASTE PACKAGE LOADING CURVE EVALUATION
44-BWR WASTE PACKAGE LOADING CURVE EVALUATION
The objective of this calculation is to evaluate the required minimum burnup as a function of initial boiling water reactor (BWR) assembly enrichment that would permit loading of spent nuclear fuel into the 44 BWR waste package configuration as provided in Attachment IV. This calculation is an application of the methodology presented in ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003). The scope of this calculation covers a range of enrichments from 0 through 5.0 weight percent (wt%) U-235, and a burnup range of 0 through 40 GWd/MTU.
Waste Package Probabilistic Criticality Analysis: Summary Report of Evaluations in 1997
Waste Package Probabilistic Criticality Analysis: Summary Report of Evaluations in 1997
The purpose of this document is to summarize the degraded waste package disposal criticality evaluations which were reported in FY 1997 (Refs. 2-6), and to explain how those evaluations have served to further develop various aspects of the overall methodology for such evaluations.
Assessment of Reactivity Margins and Loading Curves for PWR Burnup-Credit Cask Designs
Assessment of Reactivity Margins and Loading Curves for PWR Burnup-Credit Cask Designs
This report presents studies to assess reactivity margins and loading curves for pressurized water reactor
(PWR) burnup-credit criticality safety evaluations. The studies are based on a generic high-density 32-
assembly cask and systematically vary individual calculational (depletion and criticality) assumptions to
demonstrate the impact on the predicted effective neutron multiplication factor, keff, and burnup-credit
loading curves. The purpose of this report is to provide a greater understanding of the importance of
Assessment of Fission Product Cross-Section Data for Burnup Credit Applications
Assessment of Fission Product Cross-Section Data for Burnup Credit Applications
Past efforts by the Department of Energy (DOE), the Electric Power Research Institute (EPRI), the Nuclear Regulatory Commission (NRC), and others have provided sufficient technical information to enable the NRC to issue regulatory guidance for implementation of pressurized-water reactor (PWR) burnup credit; however, consideration of only the reactivity change due to the major actinides is recommended in the guidance.
Range of Applicability and Bias Determination for Postclosure Criticality of Commercial Spent Nuclear Fuel
Range of Applicability and Bias Determination for Postclosure Criticality of Commercial Spent Nuclear Fuel
The purpose of this calculation report, Range of Applicability and Bias Determination for Postclosure
Criticality of Commercial Spent Nuclear Fuel, is to validate the computational method used to perform
postclosure criticality calculations. The validation process applies the criticality analysis methodology
approach documented in Section 3.5 of the Disposal Criticality Analysis Methodology Topical Report.1
The application systems for this validation consist of waste packages containing transport, aging, and
STARBUCS: A Prototypic SCALE Control Module for Automated Criticality Safety Analyses Using Burnup Credit
STARBUCS: A Prototypic SCALE Control Module for Automated Criticality Safety Analyses Using Burnup Credit
STARBUCS is a new prototypic analysis sequence for performing automated criticality safety analyses of spent fuel systems employing burnup credit. A depletion analysis calculation for each of the burnup-dependent regions of a spent fuel assembly, or other system containing spent fuel, is performed using the ORIGEN-ARP sequence of SCALE. The spent fuel compositions are then used to generate resonance self-shielded cross sections for each region of the problem, which are applied in a three-dimensional criticality safety calculation using the KENO V.a code.
Parametric Study of the Effect of Control Rods for PWR Burnup Credit
Parametric Study of the Effect of Control Rods for PWR Burnup Credit
The Interim Staff Guidance on burnup credit for pressurized water reactor (PWR) spent nuclear fuel (SNF), issued by the United States Nuclear Regulatory Commission's (U.S. NRC) Spent Fuel Project Office, recommends the use of analyses that provide an "adequate representation of the physics" and notes particular concern with the "need to consider the more reactive actinide compositions of fuels burned with fixed absorbers or with control rods fully or partly inserted." In the absence of readily available information on the extent of control rod (CR) usage in U.S.
Sensitivity and Uncertainty Analysis of Commercial Reactor Criticals for Burnup Credit
Sensitivity and Uncertainty Analysis of Commercial Reactor Criticals for Burnup Credit
The purpose of this study is to provide insights into the neutronic similarities that may exist between a
generic cask containing typical spent nuclear fuel assemblies and commercial reactor critical (CRC) state-
points. Forty CRC state-points from five pressurized-water reactors were selected for the study and the
type of CRC state-points that may be applicable for validation of burnup credit criticality safety
calculations for spent fuel transport/storage/disposal systems are identified. The study employed cross-
End Effect keff Cias Curve for Actinide-Only Burnup Credit Casks
End Effect keff Cias Curve for Actinide-Only Burnup Credit Casks
A conservative end effect keff bias curve for actinide-only burnup credit casks is presented
in this paper. Rather than performing axially burnup-dependent analysis, cask designers can, if
they choose to, analyze casks with a uniform axial burnup (at assembly average burnup value) and
add the keff bias values to conservatively bound the actinide-only end effect. Earlier studies
suggested 1-3% increase in keff to account for the end effect, but they included fission products
as well as actinides for their analyses.
Review of Information for Spent Nuclear Fuel Burnup Confirmation
Review of Information for Spent Nuclear Fuel Burnup Confirmation
The Interim Staff Guidance on burnup credit (ISG-8, revision 2) for pressurized-water-reactor spent
nuclear fuel in storage and transport casks, issued in 2002 by the U.S. Nuclear Regulatory Commission’s
Spent Fuel Project Office, recommends an out-of-core burnup measurement to confirm the reactor record
and compliance with the assembly burnup value used for cask loading acceptance. This recommendation
is intended to prevent unauthorized loading (i.e., misloading) of assemblies due to inaccuracies in reactor
Isotopic Analysis of High-Burnup PWR Spent Fuel Samples from the Takahama-3 Reactor
Isotopic Analysis of High-Burnup PWR Spent Fuel Samples from the Takahama-3 Reactor
This report presents the results of computer code benchmark simulations against spent fuel radiochemical assay
measurements from the Kansai Electric Ltd. Takahama-3 reactor published by the Japan Atomic Energy
Research Institute. Takahama-3 is a pressurized-water reactor that operates with a 17 × 17 fuel-assembly design.
Spent fuel samples were obtained from assemblies operated for 2 and 3 cycles and achieved a maximum burnup
of 47 GWd/MTU. Radiochemical analyses were performed on two rods having an initial enrichment of
Calculation of Isotopic Bias and Uncertainty for BWR SNF
Calculation of Isotopic Bias and Uncertainty for BWR SNF
The objective of Calculation of Isotopic Bias and Uncertainty for BWR SNF is to quantify the computational bias and uncertainty in the multiplication factor (keff) to be used for Boiling Water Reactor (BWR) spent nuclear fuel (SNF) burn-up credit. The scope of this bias and uncertainty determination covers 38 different radiochemical assay (RCA) spent fuel samples from 14 different fuel assemblies that were irradiated in four different BWRs. The irradiated fuel samples evaluated span an enrichment range of 2.53 weight percent U-235 through 3.95 weight percent U-235.
Application of Sensitivity/Uncertainty Methods to Burnup Credit Criticality Validation
Application of Sensitivity/Uncertainty Methods to Burnup Credit Criticality Validation
Evaluation of the French Haut Taux de Combustion (HTC) Critical Experiment Data
Evaluation of the French Haut Taux de Combustion (HTC) Critical Experiment Data
In the 1980s, a series of critical experiments referred to as the Haut Taux de Combustion (HTC)
experiments was conducted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) at the
experimental criticality facility in Valduc, France. The plutonium-to- uranium ratio and the isotopic
compositions of both the uranium and plutonium used in the simulated fuel rods were designed to be
similar to what would be found in a typical pressurized-water reactor fuel assembly that initially had an
Evaluation of Cross-Section Sensitivities in Computing Burnup Credit Fission Product Concentrations
Evaluation of Cross-Section Sensitivities in Computing Burnup Credit Fission Product Concentrations
U.S. Nuclear Regulatory Commission Interim Staff Guidance 8 (ISG-8) for burnup credit covers actinides only, a position based primarily on the lack of definitive critical experiments and adequate radiochemical assay data that can be used to quantify the uncertainty associated with fission product credit.