Ukraine's nuclear regulator has issued a permit to SSE Chernobyl Nuclear Power Plant (ChNPP) for the retrieval of undamaged used nuclear fuel from the ISF-1 interim used fuel wet storage facility. The fuel will be moved into the new ISF-2 dry storage facility. The State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) has also issued a licence for the operation of the Liquid Radioactive Waste Treatment Plant at the Chernobyl site.

ChNPP Acting Director General Valeriy Seyda was presented with the fuel transfer permit by SNRIU head Hryhorii Plachkov on 21 May (Image: SNRIU)

More than 21,000 used fuel assemblies accumulated at the Chernobyl site between 1977 and 2000 when its four RBMK reactors were generating electricity. These are currently held in the wet-type ISF-1. This facility is not designed for long-term storage of fuel and its service life is limited, so all used fuel assemblies are to be moved to the newly-built dry-type ISF-2 intermediate storage facility. Each of the fuel assemblies will be disassembled into three parts - two fuel bundles and an activated connecting rod - in a purpose-built 'hot cell', packaged in double-walled transportable canisters and placed into ISF-2.

The ISF-2 has been financed by the international community and the European Bank for Reconstruction and Development. Described by the bank as the largest dry used fuel storage facility in the world, it cost EUR400 million (USD490 million) and was financed with contributions from Belgium, Canada, Denmark, the European Union, Finland, France, Germany, Italy, Japan, the Netherlands, Norway, Russia, Sweden, Switzerland, Ukraine, the UK and the USA.

The dry storage project began in 1999, and was taken over from Framatome by Holtec International in 2011. The ISF-2 was completed in 2019. Hot commissioning began in September 2020, and the first canister of used fuel was placed in the facility in November. SNRIU issued an operating licence for the ISF-2 facility on 23 April this year.

ChNPP said issuance of the permit to transfer fuel from ISF-1 enables it to start the next important stage of decommissioning the Chernobyl plant.

"Currently, all used nuclear fuel in Chernobyl units 1, 2 and 3 is kept in the spent fuel pools of the licensed ISF-1. The granted permit allows ChNPP to commence the transportation and placement of the standard nuclear fuel for long-term storage," said Kostiantyn Shefer, ChNPP Deputy Director General for Licensing and Departmental Supervision. "For removal of 'damaged' nuclear fuel from ISF-1, which demands taking additional safety measures, ChNPP must obtain a new permit in the future."

The transfer of the fuel from ISF-1 to ISF-2 will take place over the next 10 years, with fuel loading operations monitored by the International Atomic Energy Agency and the SNRIU. Once all fuel has been transferred, the ISF-1 facility will be decommissioned.

SNRIU has also issued ChNPP with an operating licence for the Liquid Radioactive Waste Treatment Plant (LRTP) at Chernobyl.

ChNPP said it can now process and store all of the liquid radioactive waste generated through the operation and decommissioning of the Chernobyl plant.

Up until now, ChNPP has operated the LRTP on basis of an individual permit, issued at the end of 2014, within the Chernobyl plant decommissioning licence. Having implemented alterations to nuclear legislation, ChNPP has now licensed the operation of the LRTP as an independent radioactive waste management facility.