South Korea’s Doosan Enerbility has signed a contract with Korea Hydro & Nuclear Power (KHNP) to carry out the overall design of a used nuclear fuel dry storage system. The contract was awarded following an international competitive tender. Doosan Enerbility will be completing the design work and obtaining certification by 2027 for the dry storage system, which includes the cask for storing and transporting used nuclear fuel.

The used fuel from NPPs will first be cooled in a used fuel pool for five years, after which it will be removed from the pool and moved outside for dry storage. The casks used in this process need to be designed to ensure safety and protection from radiation and heat.

The nuclear industry estimates that approximately 2,800 casks will be needed for the dry storage and interim storage facilities in the Korean market, which is expected to be worth KRW8,400bn ($6.5bn) by 2060. Doosan Enerbility plans to work in collaboration with its 140 small-to-medium sized partner companies spread across the various regions in an effort to promote the Korean domestic nuclear power industry.

“This contract holds huge significance as it was won with our locally-developed cask,” said Jongdoo Kim, CEO for Doosan Enerbility’s Nuclear Business Group. “This essentially laid the foundation for our Korean-standard used nuclear fuel storage & transportation cask business, for which we forecast there will be new orders amounting to trillions of Korean won in the future.” He added: “By working together with our small-to-medium sized local partners in Korea, we aim to do our utmost to enhance our manufacturing competitiveness, as we seek to also venture into the areas of interim storage and permanent disposal of spent nuclear fuel.”

Doosan Enerbility signed a technology cooperation agreement with the US NAC (Nuclear Assurance Corporation) in 2015, after which a range of casks applicable to various environments in the Korean and global market was developed. In 2017, Doosan completed development of the DSS-21, a dry storage system that has the capacity to safely store and transport up to 21 used fuel assemblies. Since then, the DSS-24 and DSS-32 models, upgraded versions with larger storage capacities, were developed, along with the DPC-24, a cask that can be used for both storage and transporting of used fuel.

Doosan and NAC also jointly developed a Korean-type metal storage overpack (MSO-37) for a Korean project and for which design certification was obtained from the US Nuclear Regulatory Commission (NRC). In 2019, Doosan was the first Korean company to win a used fuel cask supplier contract for unit 1 of the US Three Mile Island (TMI) NPP. This was followed by in 2021 by a similar contract for TMI 2, which is currently underway.

Image: Manufacturing of the casks for the Three Mile Island nuclear power plant in the US (courtesy of Doosan Enerbility)