The Siting Record
The Siting Record
An Account of the Programs of Federal Agencies and Events That Have Led to the Selection of a Potential Site for a Geologic Repository for High-Level Radioactive Waste
An Account of the Programs of Federal Agencies and Events That Have Led to the Selection of a Potential Site for a Geologic Repository for High-Level Radioactive Waste
The benefits of burnup credit and the technical issues associated with utilizing burnup credit in spent
nuclear fuel (SNF) casks have been studied in the United States for almost two decades. The issuance of the
U.S. Nuclear Regulatory Commission (NRC) staff guidance for actinide-only burnup credit in 2002 was a
significant step toward providing a regulatory framework for using burnup credit in transport casks. However,
adherence to the current regulatory guidance (e.g., limit credit to actinides) enables only about 30% of the existing
The validity of the computation of pressurized-water-reactor (PWR) spent fuel isotopic
composition by the SCALE system depletion analysis was assessed using data presented in the report.
Radiochemical measurements and SCALE/SAS2H computations of depleted fuel isotopics were
compared with 19 benchmark-problem samples from Calvert Cliffs Unit 1, H. B. Robinson Unit 2,
and Obrigheim PWRs. Even though not exhaustive in scope, the validation included comparison of
predicted and measured concentrations for 14 actinides and 37 fission and activation products.
The purpose of this scientific analysis report, Commercial Spent Nuclear Fuel Igneous Scenario Criticality Evaluation, is to investigate the effects of an igneous intrusion event occurring in the repository on commercial spent nuclear fuel (CSNF) stored in waste packages. This activity supports the Postclosure Criticality Department's development of bounding (design-basis) configurations for loading specifications and the evaluation of features, events, and processes (FEPs) that could lead to waste package criticality.
This report presents the analysis and conclusions with respect to disposal criticality for canisters containing aluminum-based fuels from research reactors. The analysis has been divided into three phases. Phase I, dealt with breached and flooded waste packages containing relatively intact canisters and intact internal (basket) structures; Phase II, the subject of this report, covers the degradation of the spent nuclear fuel (SNF) and structures internal to the codisposal waste package including high level waste (HLW), canisters, and criticality control material.
Thep purpose of this calculation is to perform degraded mode criticality evaluations of plutonium disposed in a ceramic waste form and emplaced in a Monitored geologic Repository (MGR). A 5 Defense High-Level Waste (DHLW) Canister Waste Package (WP) design, incorporating the can-in-canister concept for plutonium immobilization is considered in this calculation. Each HLW glass pour canister contains 7 tubes. Each tube contains 4 cans, with 20 ceramic disks (immobilized plutonium) in each.
The first objective of this calculation is the identification of the degraded configurations of the Enhanced Design Alternatives (EDA) II design that have some possibility of criticality and that can occur within 10,000 years of placement in the repository. The next objective is to evaluate the criticality of these configurations and to estimate the probability of occurrence for those configurations that could support criticality.
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 the transportation, aging and disposal (TAD) canister-based systems.
This report attempts to summarize and consolidate the existing knowledge on axial
burnup distribution issues that are important to burnup credit criticality safety calculations.
Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup
credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity
difference between the neutron multiplication factor (keff) calculated with explicit representation
The Centralized Interim Storage Facility (CISF) is designed as a temporary, above-ground away-from-reactor spent fuel storage installation for up to 40,000 metric tons of uranium (MTU). The design is non-site-specific but incorporates conservative environmental and design factors (e.g., 360 mph tornado and 0.75 g seismic loading) intended to be capable of bounding subsequent site-specific factors. Spent fuel is received in dual-purpose canister systems and/or casks already approved for transportation and storage by the Nuclear Regulatory Commission (NRC).
The means to prevent and control criticality must be addressed as part of the Preclosure Safety Analysis (PCSA) required for compliance with 10 CFR Part 63 [DIRS 180319], where the preclosure period covers the time prior to permanent closure activities. This technical report presents the nuclear criticality safety evaluation that documents the achievement of this objective.
This report summarizes the results of an initial investigation into the uncertainties associated with the burnup records maintained by nuclear power plants. The results indicate that there is an overall uncertainty of about 2 percent in the burnup records, which must be accounted for in spent fuel applications.
Uncertainties in the predicted isotopic concentrations in spent nuclear fuel represent one of the largest
sources of overall uncertainty in criticality calculations that use burnup credit. The methods used to
propagate the uncertainties in the calculated nuclide concentrations to the uncertainty in the predicted
neutron multiplication factor (keff) of the system can have a significant effect on the uncertainty in the
safety margin in criticality calculations and ultimately affect the potential capacity of spent fuel transport
This document contains analyses and calculations of absorbed dose from dispersed waste forms from light water reactors. The design features of HEPA filters are compared to the results. The calculation determines the consequences from normal operations and event sequences from surface and subsurface facilities during the preclosure period.
The purpose of this calculation is to document the Quad Cities Unit 2 boiling water reactor (BWR) fuel depletion calculations performed as part of the commercial reactor critical (CRC) evaluation program. The CRC evaluations constitute benchmark calculations that support the development and validation of the neutronics models used for criticality analyses involving commercial spent nuclear fuel in a geologic repository. The revision of this calculation incorporates control blade effects and minor variations in the SAS2H assembly modeling.
Burnup credit is an ongoing technical concern for many countries that operate commercial
nuclear power reactors. In a multinational cooperative effort to resolve burnup credit issues, a
Burnup Credit Working Group has been formed under the auspices of the Nuclear Energy Agency
of the Organization for Economic Cooperation and Development. This working group has
established a set of well-defined calculational benchmarks designed to study significant aspects of
burnup credit computational methods. These benchmarks are intended to provide a means for the
The objectie of this calculation is to document the Grand Gulf, Unit 1, (GG1) fuel depletion calculations. The GG1 reactor is a boiling water reactor (BWR) owned and operated by Entergy Operations Inc. The Commercial Reactor Criticality (CRC) evaluations support the development and validation of the neutronic models used for criticality analyses involving commercial spent nuclear fuel in a geologic repository. This calculation is performed as part of the evaluation CRC program. This report is an engineering calculation supporting the burnup credit methodology of YMP 2000 (Ref.
The purpose of this calculation is to estimate the probability of misloading a commercial spent
nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or
burnup) outside the waste package design. The waste package designs are based on the expected
commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1
and Table 1). For this calculation, a misloaded waste package is defined as a waste package that
About 20,000 metric tons of spent, or used, nuclear
fuel have accumulated since the beginning of commercial
nuclear power prbduction in the United States. At the end
of the currently licensed period of all existing nuclear power
plants and those under construction, the amount of spent
nuclear fuel is expected to total 87,000 metric tons.
Thus far, practically all of the spent nuclear fuel is
stored in water-filled pools at reactor sites. However, space
does not exist in the pools to store all the spent fuel expected
This report proposes and documents a computational benchmark problem for the estimation of the additional reactivity margin available in spent nuclear fuel (SNF) from fission products and minor actinides in a burnupcredit storage/transport environment, relative to SNF compositions containing only the major actinides. The benchmark problemlconfiguration is a generic burnup credit cask designed to hold 32 pressurized water reactor (PWR) assemblies.
Reactor physics computer programs are important tools that will be-used to estimate mixed oxide
fuel (MOX) physics performance in support of weapons grade plutonium disposition in U.S. and
Russian Federation reactors. Many of the computer programs used today have not undergone
calculational comparisons to measured data obtained during reactor operation. Pin power, the
buildup of transuranics, and depletion of gadolinium measurements were conducted (under Electric
Power Research Institute sponsorship) on uranium and MOX pins irradiated in the Quad Cities-l
Dear Secretary Chu:
At the direction of the President, you charged the Blue Ribbon Commission on America’s
Nuclear Future with reviewing policies for managing the back end of the nuclear fuel
cycle and recommending a new plan. We thank you for choosing us to serve as Co-
Chairmen of the Commission and for selecting the talented and dedicated set of
Commissioners with whom we serve.
We have sought to ensure that our review is comprehensive, open and inclusive. The
Commission and its subcommittees have heard from hundreds of individuals and
The purpose of this calculation is to determine the required minimum burnup as a function of initial pressurized water reactor (PWR) assembly enrichment that would permit loading of fuel into the 21 PWR waste package (WP), as provided for in QAP-2-0 Activity Evaluation, Perform Criticality, Thermal, Structural, & Shielding Analyses (Reference 7.1).