Russian officials earlier this week shut off a block of the Beloyarsk nuclear power station after picking up a “false” response from the facility’s safety system, according to Rosenergoatom, the utility branch of Rosatom, the state nuclear corporation.
The early morning stoppage affecting the plant’s number 4 reactor which is the BN-800 fast reactor that Rosatom brought online in 2016.
“The stoppage was carried out under a routine algorithm,” Rosenergoatom said in a statement, adding that there was nothing unusual about the radiation levels surrounding the plant, which houses another fast rector, called the BN-600, as well as two AMB series reactors that have been shut down.
The stoppage comes amid heightened concerns about Russian nuclear facilities following a deadly explosion at an Arkhangelsk area rocket testing facility, which caused local radiation levels to spike briefly. Moscow has yet to offer a complete explanation of those August 8th events, which involved what Rosatom has described as an “isotope power source.”
Medical officials Arkhangelsk the area told the media they had treated patients exposed to radioactivity, and authorities ordered an evacuation that was later called off for reasons they would not clarify.
Beloyarsk’s number 4 reactor is a powerful sodium-cooled fast-breeder unit and its operation marks a step by Russia toward developing a closed nuclear fuel cycle – a subject of concern to some environmentalists and nonproliferation experts.
It has been billed in the Russian media as being capable of using waste from traditional nuclear reactors, thus reducing the amount of radioactive waste that needs to be stored in permanently sealed repositories. Some have also speculated that it could be capable of burning surplus Soviet weapons grade plutonium, though Rosatom has yet to endorse it for that purpose.
But the reactor’s reliance on mixed uranium oxide fuel, which is fashioned on a mixture of uranium and plutonium, could pose proliferation risks if it were put into commercial operation elsewhere in the world.
Physicists have also pointed to known problems in other reactors using sodium-based cooling system similar to that used by the BN-800. Some of those reactors have reported that sodium’s high reactivity when it comes into water has caused coolant instabilities.
While there were no coolant issues reported during the BN-stoppage this week, the event nonetheless drove headlines head lines at a time when Russia’s credibility relatives to nuclear mishaps is especially low.
The Russian Defense Ministry initially said no radiation had been released in the August 8th rocket explosion, although the city administration in Severodvinsk – a port city of 183,000 located about 20 kilometers away from were the accident occurred – reported a brief rise in radiation levels on the day of the accident.
The Defense Ministry sought to censor that report, but by the following Tuesday, Russia’s state weather agency Rosgidromet said that radiation levels had spiked by four to 16 times beyond natural background levels in the city.
It was also reported that Russia had shut down many of its radiation monitors in the wake of the accident, fueling suspicions that Moscow was obscuring the true extent of the damage. Rosatom has confirmed that five of its scientists died in the accident, though a final death toll remains unknown.