A failure in Russias worn out electric grid led to a blackout in the Ural regions, prompting emergency shutdowns at three nuclear reactors, including those at the Mayak reprocessing plant located in Chelyabinsk County.
Officials went out assuring the public that no radioactivity slipped out and everything was under their control but the nervousness was hard to disguise. The head of the Mayak plant, Vitaliy Sadovnikov, said that only his staffs near military discipline prevented the worst scenario developing at the plants two operational reactors.
In an interview with a local daily Chelyabinsky Rabochy, Sadovnikov said that he learned about the problems in the grid at around 10:30 Moscow time on Saturday, September 9. During the next three-four minutes, Mayak was completely cut off.
Sadovnikov assured that the reactors were automatically shutdown and no release of radioactivity was detected. He admitted, however, that the redundancy electricity supply systems designed to cool down the reactors in emergency situations were started up only 30 minutes after the shutdown.
One of the reactors was reportedly being under preparation for start-up on Monday, September 11.
Sadovnikov would not mention whether the reprocessing plant was in operation at the time of the blackout and whether it experienced any troubles.
It was in Mayak that the plutonium for the first Soviet nuclear bomb was produced in 1949. Today Mayak operates two reactors called Ruslan and Lyudmila. The heavy water moderated reactor Ruslan was put into operation in the end of 40-s to produce tritium and specific isotopes such as 238Pu for nuclear weapon. It was redesigned towards the end of 80-s to a light water reactor with a capacity of 1000 MW. Lydmila is a 1000 MW light water reactor producing tritium and various isotopes, including 238Pu. Mayak also operates a reprocessing facility, which is capable of treating fuel from VVER-440 reactors, maritime PWR reactors, and some research reactors.
Sadovnikov stated that the blackout was the worst one his plant ever experienced. He also added that such situation could theoretically result in an accident followed by radioactivity discharge.
Shutdown at Beloyarsk NPP
But the first reactor effected by the disturbances in the grid was unit number 3 at Beloyarsk nuclear power plant in Sverdlovsk County. Officials say the reactor was shutdown automatically at 10:15 Moscow time on September 9.
The local residents, however, said they heard a loud noise coming from the plant at the time of the shutdown. Unofficial sources suggest that the plants personnel had to shutdown the reactor manually and had troubles starting up the emergency power supply systems to cool it down. The noise heard by the residents was apparently the steam gushing out from the reactors third cooling plant that is equipped with plugs, which open up if the pressure is growing beyond the permissible limits.
Beloyarsk NPPs fast-breeder BN-600 reactor was built in 1980 and currently is the only one in operation. The reactor is said to be back online on September 13. The two other reactors at the plant were taken out of service in 1981 and 1988 respectively.
The construction of a new reactor of BN-800 type was launched in 1984 but was later frozen in early 90-s. Russian Ministry for Nuclear Energy says they will restart the works at the construction site in 2001. Russian President Vladimir Putin was advertising BN-type reactors in New York last week referring to them as the most hi-tech reactors designed by Russian scientists, which could spare the world of the non-proliferation issue. The reactors were designed more than 30 years ago and so far have not been a successful venture.