The first cask of used nuclear fuel was moved to dry storage at the Krško nuclear power plant in Slovenia on April 2, officially marking the storage facility’s commissioning, announced Holtec International, which is conducting the fuel transfer campaign.
According to Holtec, the current fuel loading campaign will consist of a total of 16 of the company’s HI-STORM FW casks being placed in dry storage.
The facility: Plant operator Nuklearna elektrarna Krško (NEK) received the operating license for the dry storage facility, the plant’s first, from the Slovenian Nuclear Safety Administration last October. The Krško facility was built under the management of Holtec’s Civil Design and Construction Department with the assistance of local supply chains, primarily consisting of Slovenian, Croatian, and Italian companies.
“Our success is a testament to the teamwork and ingenuity of the transnational project team that executed the project,” said Rick Springman, Holtec’s senior vice president of international projects. “Holtec, NEK, and our local partners stood together, committed to delivering the facility even through the pandemic and uncertain market conditions caused by Russia’s aggression in Ukraine.”
According to Holtec, the facility is designed to withstand earthquake levels only encountered in high seismic regions of the world, such as California and the Western Pacific, although the seismic hazard at the site is not as high as those regions. The facility is also designed to function under severe flood conditions.
Additional monitoring: The Slovenian environmental permitting process for the facility, in accordance with European Unition rules, included a transboundary impact assessment in conjunction with neighboring countries. As part of the transboundary commenting process, it was decided to implement a nonintrusive leak-indication system to continuously monitor the welded multipurpose canisters containing the fuel, Holtec said. The system monitors the temperature profile of the casks to detect potential depressurization.
Because the HI-STORM FW system is designed and licensed as “leak-tight,” meaning a leak is not deemed credible by regulators, Holtec said the system serves only as an additional safety measure.