US-based Deep Isolation EMEA has been contracted by Slovenia’s Agency for Radwaste Management (ARAO) and Croatia’s fund for financing the decommissioning of the Krško NPP (Fond-NEK), to deliver a cost study for the potential borehole disposal of used fuel and high-level wastes from the Krško plant.

Croatia’s Hrvatska elektroprivreda (HEP) and Slovenia's GEN Energija co-own the Krško NPP, which is located in Slovenia near the border with Croatia. The plant annually covers about 20% of Slovenia's and about 16% of Croatia's needs for electricity. The single unit NPP hosts a 696 MWe Westinghouse pressurised water reactor (PWR).

This eight-month study will examine the costs associated with disposal of the two countries’ shared inventory of PWR used fuel assemblies in either generic crystalline basement geologies or shale geologies such as at the Krško power plant. It will include cost comparisons for repository architectures based on both vertical and horizontal boreholes. The results are due to be delivered to ARAO and Fond-NEK in February 2024.

ARAO’s Head of Planning and Development, Leon Kegel said: “We are working in parallel to update our estimates for the option to construct a mined repository for this waste, as well as working with Deep Isolation to quantify the economic benefits of the deep borehole option. These projects will provide us with important cost data to inform our updated waste management strategy for Krško in 2024.”

The project builds on previous work that Deep Isolation has undertaken for Croatia and Slovenia. These include a preliminary high-level cost review undertaken as part of a wider review of deep borehole disposal across European countries that are members of the ERDO Association (Slovenia, Croatia, Netherlands, Norway, Italy, Denmark and Belgium). Deep Isolation also carried out a study for ARAO in exploring boreholes as a safe and economic option for the disposal of Slovenia’s TRIGA II research reactor waste.

“The inventory of waste at Krško is extremely well suited to boreholes and we are keen to help the governments of Croatia and Slovenia to optimize their waste management strategy for Krško,” said Chris Parker, Managing Director for Deep Isolation EMEA.

Leon Kegel, head of planning & development at ARAO, said: "We are working in parallel to update our estimates for the option to construct a mined repository for this waste, as well as working with Deep Isolation to quantify the economic benefits of the deep borehole option. These projects will provide us with important cost data to inform our updated waste management strategy for Krško in 2024."

Image: The Krško nuclear plant site (courtesy of NEK)