The transfer of undamaged used fuel to an on-site interim storage facility from units 1 to 3 of the Chernobyl nuclear power plant in Ukraine has now been completed.
On the 28th of September 2013, the final undamaged used fuel assembly from unit 1 was transferred to one of the five compartments in the cooling pool of the existing wet-type interim storage facility 1 (ISF-1). Since December 2011, a total of 1333 used fuel assemblies were transferred from the unit. The transfer of all undamaged fuel from unit 3 to ISF-1 was completed in September 2010, while the last from unit 2 was moved in November 2012.Used nuclear fuel from Chernobyl 1, 2 and 3 has been progressively removed from plant cooling ponds and the reactor cores as part of an overall decommissioning program, separate from dealing with the destroyed unit 4. During the entire operation of the Chernobyl plant, more than 21,000 used fuel assemblies accumulated at the site.
Workers continue to address the issue of removing some damaged fuel assemblies which remain in units 1 and 2, the plant said, without specifying the nature of the damage or the number of assemblies remaining.
ISF-1 was commissioned in 1986, but its existing design does not allow for the storage of all the used fuel assemblies. A dry-type interim fuel storage facility (ISF-2) is under construction by US-based Holtec International under a contract signed with Ukraine in September 2007. Once completed in 2015, it will be used to store all the used fuel on the site for at least 100 years.
On 26 April 1986, a power runaway event in Chernobyl unit 4 wrecked the reactor, leading to a hydrogen explosion that destroyed the reactor building and exposed the radioactive remains of the reactor core. 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.
Source: World Nuclear News