Intact and Degrade Mode Criticality Calculations for the Codisposal of TMI-2 Spent Nuclear Fuel in a Waste Package

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 scope of this calculation is limited to the determination of the effective neutron multiplication factor (keff) for both intact and degraded mode internal configurations of the waste package. These calculations will support the analysis that will be performed to demonstrate the technical viability for disposing of low-enriched spent nuclear fuel at yucca mountain. There are no limitations on the use of the results of this calculation.