Vitrification facility stopped at Mayak

According to Russian weekly Ogoneyok on March 3, the vitrification facility for high level liquid wastes at Mayak reprocessing facility in Siberia, was taken out of operation early this year. At the time, the facility was 2,5 years past its operational limits.

Environmental activist Natalya Mironova, reporting from Chelyabinsk, confirms that the facility is now out of operation.

Research on vitrification of high level liquid wastes (HLW) at Mayak began in 1967, but it was to take 20 years before the first small facility was put into operation in 1987, processing around 500 litres and outputting 90 kg glass per hour. The process involved introducing radio nucleides into phosphate glass prepared in a ceramic melter. The facility was decommissioned following an accident, after 13 months of operation.

A second similar electric oven (EP-500-1) was installed in the same building, and put into operation on June 25, 1991. The vitrified wastes are stored on site in metal containers, for up to 40 years pending final disposal. Storage facilities are approx. 20 % full. The EP-500-1 had an estimated three-year operational life, but was operating till January 1997. The last permission to extend the life time of the plant was granted by the Russian State nuclear inspection – Gosatomnadzor – in June 1994. Mayak has plans to build four more vitrification installations, including one based on French technology, but progress is limited by lack of money.

By the beginning of 1995, 8100 PBq (218 MCi) from 8500 m3 of liquid waste had been vitrified. The HLW generated through reprocessing at Mayak Chemical Combine is stored in approximately 100 different containers. In 1991, the total radioactivity in these storage tanks was 30,000 PBq (823 MCi), with a total volume of between 20 000 and 30 000 m3. In 1993, 2,500 PBq (67 MCi) of stored waste was vitrified.

Since 1991, all the HLW generated by ongoing reprocessing has been vitrified. From now on, the wastes will have to be disposed of in one of the hundred storage tanks. It was one of these HLW tanks that exploded in 1957, releasing 740 PBq (20 MCi) worth of radioactive materials. About 74 PBq (2 MCi) was swept up to a height of one kilometre, leading to the radioactive contamination of certain parts of Chelyabinsk, Sverdlovsk and Tyumen counties.

Read more:

• Reprocessing plants in Siberia, Bellona Working Papers, no. 4:95

References:

Natalya Mironova, Chelyabinsk environmental group, 1997-03-10
Ogoneyok, Russian weekly, 1997-03-03
Perera, J., The Nuclear Industry in the Former Soviet Union: Transition from crisis to opportunity, vol.1, Financial Times Energy Publishing, 1997
Nilsen, T. and Bohmer, N., Reprocessing plants in Siberia, Bellona Working Papers, no. 4:95