The Monitored Geologic Repository (MGR) Waste Package Operations (WPO) of the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of Pu-ceramic waste forms. The Pu- ceramic (Refs. 1 and 2) is designed to immobilize excess plutonium from weapons production, and has been considered for disposal at the potential Yucca Mountain site.

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 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).

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

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.

There are more than 250 forms of U.S. Department of Energy (DOE)­owned spent nuclear fuel (SNF). Due to the variety of the spent nuclear fuel, the National Spent Nuclear Fuel Program (NSNFP) has designated nine representative fuel groups for disposal criticality analyses based on fuel matrix, primary fissile isotope, and enrichment. For each fuel group, a fuel type that represents the characteristics of all fuels in that group has been selected for detailed analysis.

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.

Independent spent fuel storage installations (ISFSIs) are currently licensed for 20 years. However, delays in developing permanent spent fuel disposal capability require continued ISFSI storage beyond the 20-year term. This report provides a technical basis for demonstrating the feasibility of extended spent fuel storage in ISFSIs.

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 purpose of this analysis is to provide input on the criticality potential of various degraded configurations to an analysis on the probability of a criticality event in a Pressurized Water Reactor (PWR) Advanced Uncanistered Fuel (AUCF) Waste Package (WP).

The objective of this analysis is to characterize a codisposal canister containing MIT or ORR fuel in the Five-Pack defense high level waste (DHLW) waste package (WP) to demonstrate concept viability related to use in the Mined Geologic Disposal System (MGDS) environment for the postclosure time frame. The purpose of this analysis is to investigate the disposal criticality and shielding issues for the DHLW WP and establish DHLW WP and codisposal canister compatibility with the MGDS, and to provide criticality and shielding evaluations for the preliminary DHLW WP design.

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 Emico Fermi Atomic Power Plant (Ref. 1). The Fermi fuel has been considered for disposal at the potential Yucca Mountain site.

The purpose of this calculation is to perform a parametric study to determine the effects of fission product leaching, assembly collapse, and iron oxide loss (Me203) on the reactivity of a waste package (WP) containing mixed oxide (MOX) spent nuclear fuel (SNF). Previous calculations (CRWMS M&O 1998a) have shown that the criticality control features of the WP are adequate to prevent criticality of a flooded WP for all the enrichment/ burnup pairs expected for the MOX SNF.

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 purpose of this report is to document calculations of the number of waste packages that could be damaged in a potential future igneous event intersecting a repository at YuccaMountain. The analyses include disruption from an igneous intrusion and from an igneous eruption. The analyses also support the evaluation of the potential consequences from a future event as part of the total system performance assessment (TSPA) for the license application for the Yucca Mountain Project.

Dear Tim:
As we work to complete our final recommendations to the Secretary by January 29, 2012,
we have determined that our efforts would be aided by the formation of an ad hoc
subcommittee to investigate the issue of co‐mingling of defense and commercial wastes.
Specifically, the ad hoc subcommittee would review and make a recommendation to the
Commission on the issue of whether the 1985 Presidential decision to co‐mingle defense
and commercial wastes for disposal should be revisited in light of changes that have

The purpose of this report is to develop and analyze the Engineered Barrier System (EBS) Radionuclide Transport Abstraction Model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment: Engineered Barrier System: Radionuclide Transport Abstraction Model Report (BSC 2006 [DIRS 177739]). The EBS Radionuclide Transport Abstraction (or RTA) is the conceptual model used in the Total System Performance Assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ).

Stress corrosion cracking (SCC) is one of the most common corrosion-related causes for premature breach of metal structural components. SCC is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously (Jones 1992 [DIRS 169906], Section 8.1): metallurgical susceptibility, critical environment, and sustained tensile stresses.