Fast Flux Test Facility (FFTF) Reactor Fuel Degraded Criticality Calculation: Degraded SNF Canister

The objective of this calculation is to characterize the criticality aspect of a Department of Energy Spent Nuclear Fuel (DOE SNF) canister containing 5 Fast Flux Test Facility (FFTF) assemblies in a Five-Pack Defense High-Level Waste (HLW) waste package(WP). The purpose of this calculation is to investigate the criticality issues for the WP containg HLW and DOE SNF canisters in various stages of degradation. The calculational method used to perform the criticality calculations consisted of using the MNCP Version 4B2 (Ref. 7.1) to calculate the effective neutron multiplication factor (k-eff) of the system. The calculations were performed using continuous energy cross section libraries from Evaluated Nuclear Data File (ENDF). All calculations were performed with the fresh fuel isotopics (Assumption 3.1). The HLW degraded composition was given in Table 5-14 of Reference 7.2.