Disposal criticality analysis for aluminum-based DOE fuels
- Framatome Cogema Fuels, Las Vegas, NV (United States)
- TRW Environmental Safety Systems, Inc., Las Vegas, NV (United States)
This paper describes the disposal criticality analysis for canisters containing aluminum-based Department of Energy fuels from research reactors. Different canisters were designed for disposal of highly enriched uranium (HEU) and medium enriched uranium (MEU) fuel. In addition to the standard criticality concerns in storage and transportation, such as flooding, the disposal criticality analysis must consider the degradation of the fuel and components within the waste package. Massachusetts Institute of Technology (MIT) U-Al fuel with 93.5% enriched uranium and Oak Ridge Research Reactor (ORR) U-Si-Al fuel with 21% enriched uranium are representative of the HEU and MEU fuel inventories, respectively. Conceptual canister designs with 64 MIT assemblies (16/layer, 4 layers) or 40 ORR assemblies (10/layer, 4 layers) were developed for these fuel types. Borated stainless steel plates were incorporated into a stainless steel internal basket structure within a 439 mm OD, 15 mm thick XM-19 canister shell. The Codisposal waste package contains 5 HLW canisters (represented by 5 Defense Waste Processing Facility canisters from the Savannah River Site) with the fuel canister placed in the center. It is concluded that without the presence of a fairly insoluble neutron absorber, the long-term action of infiltrating water can lead to a small, but significant, probability of criticality for both the HEU and MEU fuels. The use of 1.5kg of Gd distributed throughout the MIT fuel and the use of carbon steels for the structural basket or 1.1 kg of Gd distributed in the ORR fuel will reduce the probability of criticality to virtually zero for both fuels.
- Research Organization:
- Framatome Cogema Fuels, Las Vegas, NV (United States)
- Sponsoring Organization:
- USDOE Office of Civilian Radioactive Waste Management, Washington, DC (United States)
- DOE Contract Number:
- AC08-91RW00134
- OSTI ID:
- 658249
- Report Number(s):
- DOE/RW-98005826; ON: DE98005826; TRN: 98:011291
- Resource Relation:
- Other Information: PBD: Nov 1997
- Country of Publication:
- United States
- Language:
- English
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