Slovenia's sole nuclear power station in Krško has finished building its new dry cask storage facility for spent nuclear fuel, a EUR 100 million project that has been completed as part of the plant's latest ten-year security upgrade.

Initially, 300 tonnes of spent nuclear fuel will be transferred from the wet storage pool to the dry storage facility that was built over the past eight years using established Western technology.

Dry cask storage does not require additional systems and energy to operate it, which will makes spent fuel storage simpler, cheaper and safer, the management said on 17 March.

The new facility will last for at least the next 100 years, and spent fuel will be stored there after five years of cooling in the dedicated pool.

In the first stage, 16 containers with 592 fuel cells will be moved from this pool by the autumn. The second stage is planned for 2028, when another 16 containers with the same number of fuel elements will be relocated. Two more stages will follow.

The facility has enough room to accommodate spent fuel generated in the entire lifespan of the plant's unit one, said Saša Medaković, a member of the management board.

The main advantage of dry storage is greater safety as this is a robust technical solution that protects the containers from extreme weather or earthquake hazards.

The containers should also be able to withstand a commercial aircraft crash or train collision, according to Gorazd Pfeifer, who will replace Stane Rožman at the helm of the plant's operator next month.

Other advantages include long-term cooling without operating cooling systems or with natural convection airflow only, and minimal maintenance.

From a radiation point of view, there is minimal impact on the environment, and a high level of employee and environmental safety is ensured in all operations, Pfeifer added.

The new 3,500 m2 facility has been approved by the International Atomic Energy Agency. The plant will use Holtec multi-purpose canisters. Each cylindrical container has space for 37 fuel cells, and the facility has space for 70 such containers or a total of nearly 2,600 fuel cells.

Similar storage systems are used in Belgium, Germany, Hungary, Switzerland, Spain, the UK, and in some places in the US.

The Krško Nuclear Power Plant has recently received a permit to extend the operating life by another twenty years, to 2043, while plans are afoot to build a second unit during that time.