AREVA/TRANSNUCLEAR’S NUHOMS® MP197 TRANSPORTATION PACKAGE WITH HIGHER BURNUP AND HIGHER HEAT LOAD CANISTERS AS A PAYLOAD

The AREVA/Transnuclear, Inc. (TN) licensed NUHOMS® MP197 Transportation Package is licensed for transportation of used fuel assemblies (SFAs) under U.S. Nuclear Regulatory Commission (NRC) requirements of 10CFR Part 71, Certificate of Compliance (CoC) No. 9302. The MP197 Transportation Package includes the NUHOMS® -61BT Canister as a payload with maximum heat load of 15.86 kW. The NUHOMS® -61BT Canister is currently licensed for storage under the requirements of 10CFR Part 72 with a maximum heat load of 18.3 kW. As burnups of the discharged SFAs from nuclear reactors are increasing, decay heats from these SFAs are also increasing. The dry storage systems currently been procured by the utilities have high burnup, high heat load SFAs. Design enhancements are made to the 61BT canister to increase the heat load for storage under the requirements of 10CFR Part 72 to 31.2 kW with high burnup (up to 62 GWD/MTU) and high heat load SFAs. TN has submitted an amendment application to the NRC for approval to store these high heat load, high burnup SFAs in the 61BT Canisters in the Standardized NUHOMS® CoC 1004. The design enhancements include the use of aluminum basket transition rails instead of stainless steel for improved heat transfer. The heat loads are expected to be high at the time of transportation of these SFAs. If the transportation package is not licensed for high heat loads, then there will be significantly longer cooling times required before these SFAs can be transported. To address this need, TN is planning to submit an amendment application for the MP197 Transportation Package CoC 9302 to increase the heat load up to 31 kW. Design enhancements made to the MP197 cask are the use of improved neutron shield resin material, use of heat transfer fins on the surface of the cask, and use of improved heat transfer material for the impact limiters. TN is also utilizing appropriate placement of SFAs in the 61BT canister basket locations to allow higher total heat loads.