US-based Holtec International has won a contract for the turnkey supply of a dry cask storage facility for the single-unit Krsko nuclear plant in Slovenia.

Operator Nuklearna Elektrana Krsko’s initial decision to award the contract to Holtec in May 2016 was contested by France’s Areva group leading to nine months of independent expert reviews under the auspices of Slovenia’s National Review Commission. Holtec said that the contract had now been confirmed, but did not give its value. The contract includes design and construction of a dry storage building, replacement of the fuel handling building crane trolley, and supply of equipment and services to implement dry storage.

The building is to be a fully equipped canister or cask handling facility with a temperature and radiation monitoring system, and equipment and systems to "safely execute rarely needed activities such as severing a welded canister lid", Holtec said. The casks and storage facility will be licensed in Slovenia, with additional performance criteria imposed by NEK to demonstrate safety against severe environmental phenomena and other modern hazards. Holtec will fabricate the majority of the equipment at its Heavy Manufacturing Plant at its Technology Campus in Camden, New Jersey.

Krsko is a 688MWe Westinghouse pressurised water reactor which began commercial operation in 1983.In 2001 its steam generators were replaced and the plant was uprated 6% then and 3%. Its operating period was to be 40 years, but a 20-year extension was confirmed in mid-2015, subject to inspections in 2023 and 2033.

Photo: Schematic of Holtec's HI-STORM FW system inside the dry storage building