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.

The "Summary Report of Commercial Reactor Critical Analyses Perfonned for the Disposal Criticality Analysis Methodology" contains a summary of the commercial reactor critical (CRC) analyses used to support the validation of the criticality models for spent commercial light water reactor (LWR) fuel.

This report is in response to the directive of the House Appropriations Subcommittee for Energy and Water
Development that the Department of Energy (DOE) update a 1984 report of alternative means of financing and
managing (AMFM) the Office of Civilian Radioactive Waste Management (OCRWM) in the DOE. The
President’s FY 2002 budget also stated: “DOE will submit to Congress an updated report regarding alternative
approaches to finance and manage the program by June 30, 2001[.] DOE will identify in this report models of

The objective of this calculation is to characterize the nuclear criticality safety concerns associated with the codisposal of the U.S. Department of Energy's (DOE) Shippingport Light Water Breeder Reactor (SP LWBR) Spent Nuclear Fuel (SNF) in a 5-Defense High-Level Waste (5-DHLW) Waste Package (WP), which is to be placed in a Monitored Geologic Repository (MGR).

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.

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. One of those variables

The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only.

Approximately 54,000 tons of spent nuclear fuel are stored at operating nuclear power plants and several decommissioned power plants throughout the country. Spent fuel storage at these sites was never intended to be permanent. The current Federal plan is to place the fuel in a repository for permanent disposal in Nevada at Yucca Mountain.

The Nuclear Waste Policy Act of 1982, as amended, established a statutory basis
for managing the nation’s civilian (or commercially produced) spent nuclear
fuel. The law established a process for siting, developing, licensing, and constructing
an underground repository for the permanent disposal of that waste.
Utilities were given the primary responsibility for storing spent fuel until it is
accepted by the Department of Energy (DOE) for disposal at a repository —
originally expected to begin operating in 1998. Since then, however, the repository