A contingency happened to nuclear-powered icebreaker Taimyr currently staying in Yenisei Bay. According to YouMurman, insignificant increase of airborne radioactivity was detected in reactor ventilation system, reported Yekaterina Ananieva, press secretary of Rosatom.
The icebreaker belongs to state corporation Rosatom. At present, it completes icebreaking works in the bay and is to return to homeport Murmansk in 5 days.
The contingency was detected by radiation control system. According to Ananieva, airborne radioactivity could rise due to non-compactness of primary coolant circuit. "Process parameters of primary circuit – pressure and temperature – are within normal limits; radioactivity level does not exceed control points. No radioactive release into environment was detected", Ananieva added.
Control over process parameters of reactor plant was tightened. If the situation gets worse, reactor plant would be shut down and cooling process would start. In this case the icebreaker would move by diesel engines.
There is no threat to people and environment. This event is classified by International Nuclear and Radiological Event Scale (INES) as "zero" level, i.e. out of scale.
Taimyr has not completed icebreaking escorts in Yenisei River. Nuclear icebreaker Vaigach has been already dispatched to this route after successful escort of the vessel named Kapitan Danilkin in the Gulf of Ob. Vaigach was sent there despite early ice drift in Yenisei River and almost completed winter navigation.
Reference
Taimyr is the first Russian shallow-draft nuclear icebreaker (8 meters) specially designed for operations in Siberian rivers. It was built in 1989 at Finnish shipyard Wartsila by order of the USSR. Length is 151 meters; beam is 29 meters; nuclear power plant is 50,000 shp. The year after Taimyr, the Finnish yard built icebreaker Vaigach under the same project.
FSUE Atomflot (Rosatomflot) is a member of state-led corporation Rosatom. Currently operational icebreaking fleet consists of 4 nuclear icebreakers with 75,000-shp dual-reactor plant, and 2 icebreakers with 40,000-shp single-reactor plant.