GAO Storage Study Request - Ltr to Honorable Gene Dodaro from Honorable Fred Upton and John Shimkus
GAO Storage Study Request - Ltr to Honorable Gene Dodaro from Honorable Fred Upton and John Shimkus
GAO Storage Study Request
GAO Storage Study Request
This paper presents an assessment of the benefits for extended burnup credit in transporting
pressurized-water-reactor (PWR) spent nuclear fuel (SNF) in the United States. A prototypic 32-
assembly cask and the current regulatory guidance were used as bases for this assessment. By
comparing recently released PWR discharge data with actinide-only-based loading curves, this
evaluation shows that additional negative reactivity (through either increased credit for fuel burnup or
The purpose of these calculations is to characterize the criticality safety concerns for the storage of Fast Flux Test Facility (FFTF) nuclear fuel in a Department of Energy spent nuclear fuel (DOE SNF) canister in a co-disposal waste package. These results will be used to support the analysis that will be done to demonstrate concept viability related to use in the Monitored Geologic Repository (MGR) environment.
NRC initiated a research activity with the Center for Nuclear Waste Regulatory Analyses (CNWRA®) to develop a conceptual test plan for measuring the quantity of residual water remaining in a canister following vacuum drying to the criterion referenced in NUREG–1536 (NRC, 2010). The test plan will be used to help NRC assess options for independently performing an experimental program or to support engagements with industry or the Department of Energy should they undertake a similar effort.
The purpose of this calculation is to document the Three Mile Island Unit 1 pressurized water reactor {PWR) reactivity calculations performed as part o f the commercial reactor critical (CRC) evaluation program. CRC evaluation reactivity calculations are performed at a number of statepoints, representing reactor start-up critical conditions at either beginning of life (BOL), beginning of cycle (BOC), or mid- cycle when the reactor resumed operation after a shutdown.
The purpose of this calculation file is to document criticality calculations performed on two different rod consolidation waste package designs. The results presented in this calculation file may be used to support further evaluation of the rod consolidation waste package design.
The purpose of this calculation is to document the McGuire Unit 1 pressurized water reactor (PWR) fuel depletion calculations performed as part of the commercial reactor critical (CRC) evaluation program. The CRC evaluations support the development and validation of the neutronics models used for criticality analyses involving commercial spent nuclear fuel in a geologic repository.
The criticality consequence analysis for pressurized water reactor (PWR) waste packages (WP) (Civilian Radioactive Waste Management System [CRWMS] Management and Operating Contractor [M&O] 1997) focused on results obtained by maximizing postulated rates of reactivity insertion to assure no synergistic reactions could occur among waste packages from hypothetical criticality events. Other variables potentially influencing the criticality consequences were held constant during the above referenced analysis.
This study provides results supporting the conclusion that the repository can be operated over a varying range of thermal modes and therefore temperatures. In particular, this work focused on limiting the peak, postclosure waste package surface temperature to less than 85 degrees Celsius, a possible limit due to corrosion considerations. These operating modes were compared by varying the waste package in drift spacing (0.1-2.83 meters), drift pitch (drift spacing centerline to centerline of 40-120 meters), ventilation duration (75-300 years), and ventilation efficiency (50-80%).
At the request of the staff to the Blue Ribbon Commission on America’s Nuclear Future (“BRC”), we have reviewed whether certain recommendations in the BRC’s July 29, 2011 Draft Report respecting near-term actions by the Department of Energy (“DOE”) or other officers or agencies in the Executive Branch can be implemented under existing law. These recommendations relate to:
(1) Initial steps to site, license and construct consolidated interim storage facilities for spent nuclear fuel (“spent fuel”);
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 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 briefing paper is a component of the comprehensive briefing package developed for the Negotiator, and describes previous DOE experience in its attempt to site an MRS facility. The Background section highlights, in chronological order, significant events in DOE's MRS siting history from enactment of the Nuclear Waste Policy Act of 1982 to the issuance of the "Report to Congress on Reassessment of the Civilian Radioactive Waste Management Program" in November 1989.
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.
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.
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