Understanding the changing nuclear and mechanical characteristics of used nuclear fuel (UNF) over time and how these changing characteristics affect storage, transportation, and disposal options can require many tools and types of data. To streamline analysis capabilities for the waste management system, a comprehensive, integrated data and analysis tool has been assembled—UNF-Storage, Transportation & Disposal Analysis Resource and Data System (UNF-ST&DARDS).

This analysis provides information necessary for total system performance assessment (TSPA) for the license application (LA) to include the excess U.S. Department of Energy (DOE) plutonium in the form of mixed oxide (MOX) spent nuclear fuel and lanthanide borosilicate (LaBS) glass. This information includes the additional radionuclide inventory due to MOX spent nuclear fuel and LaBS glass and the analysis that shows that the TSPA models for commercial spent nuclear fuel (CSNF) and high-level waste (HLW) degradation are appropriate for MOX spent nuclear fuel and LaBS glass, respectively.

After more than 20 years of commercial nuclear power, the Federal Government has yet to develop a broadly supported policy for fulfilling its legal responsibility for the final isolation of high-level radioactive waste. OTA's study concludes that until such a policy is adopted in law, there is a substantial risk that the false starts, shifts of policy, and fluctuating support that have plagued the final isolation program in the past will continue.

The purpose of this report, and the information contained in the associated computerized data bases, is to establish the DOE/OCRWM reference characteristics of the radioactive waste materials that may be accepted by DOE for emplacement in the mined geologic disposal system as developed under the Nuclear Waste Policy Act of 1982. This report provides relevant technical data for use by DOE and its supporting contractors and is not intended to be a policy document.

The purpose of this calculation is to develop an estimate of the isotopic content as a function of time for mixed oxide (MOX) spent nuclear fuel (SNF) assemblies in a Westinghouse pressurized water reactor (PWR). These data will be used as source data for criticality, thermal, and radiation shielding evaluations of waste package (WP) designs for MOX assemblies in the Monitored Geologic Repository (MGR).

The "Summary Report of SNF Isotopic Comparisons for the Disposal Criticality Analysis Methodology" contains a summary of the analyses that compare SNF measured isotopic concentrations (radiochemical assays) to calculated SNF isotop~c concentrations (SAS2H module ·orScale4.3). The results of these analyses are used to support the validation of the isotopic models for spent commercial light water reactor (LWR) fuel.

The Disposal Criticality Analysis Methodology Topical Report (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, Models, in that they are procedural, rather than mathematical.

In response to the remand of the U.S. Court of Appeals for the District of Columbia Circuit (Minnesota v. NRC, 602 F.2d 412 (1979)), and as a continuation of previous proceedings conducted in this area by NRC (44 Fed. Reg. 61,372), the Commission initiated a generic rulemaking proceeding on October 25, 1979.

This analysis is prepared by the Mined Geologic Disposal System (MODS) Waste Package Development (WPD) department to provide an evaluation of the criticality potential within a waste package having some or all of its contents degraded by corrosion and removal of neutron absorbers. This analysis is also intended to provide an estimate of the consequences of any internal criticality, particularly in terms of any increase in radionuclide inventory. These consequence estimates will be used as part of the WPD input to the Total System Performance Assessment.

As part of the plutonium waste form development and down-select process, repository analyses have been conducted to evaluate the long-term performance of these forms for repository acceptance. Intact and degraded mode criticality analysis of the mixed oxide (MOX) spent fuel is presented in Volume I, while Volume II presents the evaluations of the waste form containing plutonium immobilized in a ceramic matrix.

The success of the Civilian Radioactive Waste Management Program of the U.S.
Department of Energy (DOE) is critical to U.S. ability to manage and dispose of
nuclear waste safely--and to the reestablishment of confidence in the nuclear energy
option in the United States. The program must conform with all applicable standards
and, in fact, set the example for a national policy on the safe disposal of radioactive
waste.
The Secretary of Energy has recently completed an extensive review of the

The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for all spent fuels and high-level wastes (HLW) that will eventually be disposed of in a geologic repository. The purpose of this document, and the information contained in the associated computerized data bases and supporting technical reports, is to provide the technical characteristics of the radioactive waste materials that will (or may) be accepted by DOE for interim storage in an MRS or emplacement in a repository as developed under the Nuclear Waste Policy Act Amendment of 1987.

The main question before the Transportation and Storage Subcommittee was whether the United States
should change its approach to storing and transporting spent nuclear fuel (SNF) and high-level
radioactive waste (HLW) while one or more permanent disposal facilities are established.
To answer this question and to develop specific recommendations and options for consideration by the
full Commission, the Subcommittee held multiple meetings and deliberative sessions, visited several

The objective of these calculations is to perform intact and degraded mode criticality evaluations of the Department of Energy's (DOE) Three Mile Island- Unit 2 (TMI-2) spent nuclear fuel (SNF) in canisters. This analysis evaluates codisposal in a 5-Defense High-Level Waste (5-DHLW/DOE SNF) Long Waste Package (Civilian Radioactive Waste Management System Management and Operating Contractor [CRWMS M&O] 2000b, Attachment V), which is to be placed in a potential monitored geologic repository (MGR).

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?”

Since a 1985 decision by President Reagan that a separate permanent repository for disposal of
defense high level waste was not required1, DOE has planned for disposal of all high-level waste
and spent fuel from national defense activities and DOE’s own research activities in a repository
for commercial waste developed under the Nuclear Waste Policy Act (NWPA). The Commission
has heard recommendations from some commenters2 that this decision be revisited, or even