The purpose of the material degradation and release (MDR) model is to predict the fate of the waste package materials, specifically the retention or mobilization of the radionuclides and the neutron-absorbing material as a function of time after the breach of a waste package during the 10,000 years after repository closure. The output of this model is used directly to assess the potential for a criticality event inside the waste package due to the retention of the radionuclides combined with a loss of the neutron-absorbing material.

The Disposal Subcommittee of the Blue Ribbon Commission on America’s Nuclear Future (BRC) addressed a wide-ranging set of issues, all bearing directly on the central question: “How can the United States go about establishing one or more disposal sites for high-level nuclear wastes in a manner and within a timeframe that is technically, socially, economically, and politically acceptable?”

The Monitored Geologic Repository Waste Package Operations of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Navy (Refs. 1 and , 2). The Navy SNF has been considered for disposal at the potential Yucca Mountain site. For some waste packages, the containment may breach (Ref. 3), allowing the influx of water. Water in the waste package may moderate neutrons, increasing the likelihood of a criticality event within the waste package.

This guidance manual provides the NRC staff methodology for calculating parameters for limiting conditions of operation required in the radiological effluent Technical Specifications for light-water-cooled nuclear power plants. it provides guidance in using the model specifications reported in NUREG-0472 (Revision 1)*, and NUREG-0473 (Revision 1)*, applicable to operating PWR and BWR licensees, and users of the Standard Technical Specifications packages available for various vendor designs.

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.

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 Monitored Geologic Repository (MGR) Waste Package Operations (WPO) of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Shippingport Pressurized Water Reactor (PWR) (Ref. 1). The Shippingport PWR SNF has been considered for disposal at the proposed Yucca Mountain site.

The Disposal Subcommittee of the Blue Ribbon Commission on America’s Nuclear Future has
commenced to address a set of issues, all of which bear directly on the central question: “How can the
United States go about establishing one or more disposal sites for high-level nuclear wastes in a manner
and within a timeframe that is technically, socially, economically, and politically acceptable?”
To answer this question and to develop specific recommendations and options for consideration by the

The main objective of this report is to identify conditions which affect public concern (either
increase or decrease) and political acceptance for developing and implementing programmes
for geologic disposal of long-lived radioactive waste. It also looks how citizens and relevant
actors can be associated in the decision making process in such a way that their input is
enriching the outcome towards a more socially robust and sustainable solution. Finally, it
aims at learning from the interaction how to optimise risk management addressing needs and

Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013

The purpose of this document is to provide the requirements rationale for the current version of the Preliminary Transportation, Aging and Disposal Canister System Performance Specification; WMO-TADCS-000001.

The comparison of different nuclear fuel cycle options has become an integral element to any analysis of the future prospects for nuclear energy, in the United States and around the world. Concerns for supply security and price volatility of fossil fuels, combined with growing resolve to reduce the emissions of greenhouse gases, have caused a general shift in attitudes towards nuclear energy. However, there are lingering sustainability concerns for nuclear energy – long term uranium supply and environmental impact – as well as concerns about the proliferation of nuclear weapons.

America’s nuclear waste management program is at an impasse. The Obama Administration’s decision
to halt work on a repository at Yucca Mountain in Nevada is but the latest indicator of a policy that has
been troubled for decades and has now all but completely broken down. The approach laid out under
the 1987 Amendments to the Nuclear Waste Policy Act (NWPA)—which tied the entire U.S. high-level
waste management program to the fate of the Yucca Mountain site—has not worked to produce a

The Monitored Geologic Repository (MGR) Waste Package Project of the BSC Management and Operating Contractor for the Department of Energy's Office of Civilian Radioactive Waste Management performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Enrico Fermi Reactor owned by the DOE (Ref. 9). The Fermi SNF has been considered for disposal at the proposed Yucca Mountain site.

The Monitored Geologic Repository Waste Package Operations of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Training, Research, Isotopes, General Atomics (TRIGA) reactor (Ref. 1). The TRIGA SNF has been considered for disposal at the potential Yucca Mountain site.

The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management & Operating contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Shippingport Light Water Breeder Reactor (LWBR) (Ref. 1). The Shippingport LWBR SNF has been considered for disposal at the potential Yucca Mountain site.

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

The Nuclear Energy Institute, on behalf of the nuclear energy industry, is pleased to provide comments on the discussion draft of the Nuclear Waste Administration Act of 2013 and the associated documents that were released on April 25.

DOE decided to terminate the Yucca Mountain repository program because, according to DOE officials, it is not a workable option and there are better solutions that can achieve a broader national consensus. DOE did not cite technical or safety issues. DOE also did not identify alternatives, but it did create a Blue Ribbon Commission to evaluate and recommend alternatives.