Final testing of Chernobyl used fuel store

07 May 2019

Final system-wide trials began yesterday of the new dry interim used fuel storage facility at the site of the Chernobyl nuclear power plant in Ukraine. The facility is expected to be handed over to the state-owned enterprise Chernobyl Nuclear Power Plant (ChNPP) in the coming months.

The IFS2 facility at Chernobyl (Image: ChNPP)

The ISF2 facility is being constructed by the USA's Holtec International. The principal contractors on the project are Ukraine's UTEM, Germany's BNG and Italy's Maloni. The project, supported by the Nuclear Safety Account managed by the London-headquartered European Bank for Reconstruction and Development, will provide for the processing and storage of the used nuclear fuel from units 1, 2 and 3, which is required for the decommissioning of the Chernobyl plant.

"These functional dry runs follow a long series of exhaustive tests of the individual systems, structures and components within the spent nuclear fuel processing and storage complex called ISF2," Holtec said. These tests are expected to take two months to complete, the company noted. "ChNPP will then initiate commissioning of the facility beginning with 'hot' confirmatory tests."

The ISF2 project had begun in the late 1990s but was stalled when "the prior contractor's technology was shown to be inadequate to meet the facility's functional and regulatory requirements", according to Holtec, which took over the project in 2011.

"We were handed a facility full of defective equipment that had deteriorated for lack of any maintenance for nearly a decade," said Holtec's Project Manager Michael Pence. "Through the sheer commitment of our team and partners, this project, which looked nearly impossible given the poor condition of the building, shabby documentation and old equipment, with little or no hope of available replacement parts, has now reached the milestone we celebrate today."

On 26 April 1986, the Chernobyl plant suffered the worst nuclear accident in history when a power runaway event wrecked reactor 4. The three remaining reactor units, however, were vital to Ukraine's electricity needs and continued to operate for some years. Unit 2 shut down in 1991, unit 1 in 1996 and unit 3 in 2000. The plant officially entered the decommissioning phase in April last year, following approval by the Ukraine's State Nuclear Regulatory Inspectorate. The first phase of decommissioning is the so-called final shutdown and preservation stage, which is expected to take ten years. The last damaged used fuel assembly from units 1-3 of the plant was removed in June 2016 - from the cooling pool of unit 1 - and transferred to ISF1, a wet-type interim storage facility. ISF2 will store all the used fuel on the site for at least 100 years.

Holtec Ukraine's Director General Sergiy Tarakanov added, "We stand ready to assist ChNPP in the critically important fuel transfer campaign if necessary."

Energoatom, Ukraine's nuclear power plant operator, and Holtec started construction of the Central Spent Fuel Storage Facility (CSFSF) at the Chernobyl site in November 2017. It will receive used nuclear fuel from nine of Ukraine's 15 reactors - seven VVER-1000s and two VVER-440s - located at Rivne, South Ukraine and Khmelnitsky. The Zaporozhe nuclear power plant operates its own on-site used fuel storage facility that was commissioned in 2001. The CSFSF will be a dry storage facility in which the used fuel will be stored in double-walled stainless steel canisters. The facility will mean Ukraine will no longer have to spend USD200 million annually on its arrangement with Russia to transport and reprocess used nuclear fuel. The CSFSF is scheduled to enter full operation in 2020.

Researched and written by World Nuclear News