Mayak to resume waste processing

Radioaktiviteten i vannet og sedimentene er høy.
Foto: Thomas Nilsen

Publish date: October 30, 2001

Written by: Igor Kudrik

The Mayak combine in the southern Ural has reportedly commissioned a vitrification facility, which originally was scheduled to start operation in 1998.

The vitrification facility is processing high-level liquid radioactive waste, which is the by-product of spent nuclear fuel reprocessing. At the output, the waste is mixed with glass. In such form it can be stored relatively safe. Each tonne of reprocessed fuel results in around 45 cubic meters of high active liquid waste.

The old vitrification facility at Mayak was taken out of operation in early 1997. At that time the plant was 2.5 years past its operational limits. The closure of the plant prompted the Russian State Nuclear Regulatory, GAN, to withdraw the reprocessing licence from the Mayak combine in spring 1997. GAN officials said that the licence was given on the condition that the waste is vitrified. Otherwise Mayak would have to accumulate the waste in the storage tanks for highly radioactive waste, and the capacity of those tanks was limited. The licence was returned later the same year after Mayak proved they had the capacity to store the waste temporarily before installing a new vitrification facility.

The newly built vitrification facility has the same capacity as its former prototype – 500 litres of waste per hour, outputting 70kg of glass. The glass is placed into a temporary storage which is now one third full. Mayak officials say the plant will be able to process all the stored high active waste in five to six years to come.

Vitrification will not get Mayak better off

But the vitrification facility will not solve the disastrous environmental situation around Mayak. 150 cubic meters of medium and 2,000 cubic meters of low active liquid waste generated per tonne of reprocessed fuel are dumped into the Karachay Lake in the vicinity of Mayak. At the bottom of the Karachay Lake there is a lens-form formation with the dense concentration of highly radioactive waste. The ‘lens’ is gradually moving towards river system posing a threat of vast contamination.

The system of Techa River reservoirs located six kilometres from Mayak contain huge amount of highly radioactive waste in sediments resulted from direct discharge in 1950s. The reservoirs are separated from the river system by dams. Each year, depending on the level of precipitation, there is a risk that the water level will increase high enough to flow over the dams. This year the water at one of the dams was 30cm from the critical mark.

The management at Mayak say they can solve the problem if the South-Ural nuclear power plant is built in the area, which could use water from Techa reservoirs to cool the reactors. The construction of the South Ural NPP was launched in 1984. It was designed to operate on BN-800 type fast-breeder reactors. In 1987, the project was halted, but during the past couple of years the management of Mayak has been trying to put the construction of the plant back to the agenda. The main argument was the management’s ‘concern’ for the environmental situation around the Techa reservoirs.

Mayak fazing out

The RT-1 reprocessing plant at Mayak is in operation since 1956. Originally designed to reprocess weapons grade plutonium from military reactors it was later modified to handle spent nuclear fuel from VVER-440 reactors, BN-30 and BN-600 reactors, as well as PWR maritime reactors installed onboard nuclear powered submarines and nuclear powered icebreakers. RT-1 can also reprocess spent fuel from some research reactors. The plant has design capacity of 400 tonnes of spent fuel per year. But the past ten years the plant’s production level was rarely higher than 150 tonnes per year. The plans to upgrade RT-2 are not cheerfully accepted by the Ministry for Nuclear Energy, which supervises Mayak. The available reports suggest that the ministry would rather prefer to store spent nuclear fuel both from the domestic reactors and imported for a period of 20 years before a new reprocessing plant is built. The new plant – RT-2 – is located in Krasnoyarsk county. Its construction was launched 30 years ago but put on freeze in 1990s.