Number one reactor at Kalinin NPP shuts down for second time in two weeks, raising concerns

Svetlana Zakharova

Publish date: August 5, 2010

Written by: Andrey Ozharovsky

Translated by: Charles Digges

MOSCOW – The Kalinin Nuclear Power Plant has again run into trouble for the second time in two weeks after its struggling No.1 reactor was plugged back into the power grid after a stoppage occasioned by a transformer fire on July 23, only to be shut down again yesterday.

The nuclear plant, located between Moscow and St. Petersburg, has produced record lows of power output throughout July, falling short by half a million kilowatt hours of energy pumped into Russia’s energy grid.  

According to the Kalinin NPP press office, “on August 5, 2010, at 3:07, the no. 1 reactor was taken off the grid by the actions of an automatic generator switch. The reasons for the event are currently being investigated.”

The No. 1 reactor therefore worked for only 11 days after it was plugged back into the grid on July 25. The reason for the shut down on July 23 was a fire at a piece of equipment called an outdoor switchgear, or an ORU-750kV in its Russian terminology. Whether the reason for the current shutdown is another fire is still unknown. It could be that workers were not successful in completing reliable repairs on the reactor and that the problems will persist, Bellona experts say.

Earlier, Russia’s state nuclear utility Rosenergoatom said that “the outbreak of the fire and the reasons for it were likewise eliminated on July 23.” But it is apparent that not all the failures of the electrical equipment at the NPP were discovered and eradicated.  

The Kola Nuclear Power Plant in Russia’s northwest Murmansk Region ran into similar problems when its reactor unit No. 3, after a short stoppage, was not able to work for more than nine hours, and was shut down by automatic switches. Such events occur because Russia’s NPPs do not run at full power and are significantly cutting down their power contribution to the grid.

The Kalinin NPP press reported that the plant had produced “1,591 billion kilowatts per hour of electrical energy in July. One thousand four hundred and ninety four billion kilowatt hours were delivered into the energy grid. The installed capacity utilisation factor (ICUF) in July consisted of 71.29 percent.”

As such, some 6421 million kilowatt hours were not delivered into the national grid. Had the plant worked at full capacity on all three of its reactors, it would have delivered 2.332 billion kilowatt hours.

Tha Kalinin NPP’s installed capacity utilisation factor also strongly differs from the 90 percent promised by Rosatom, Russia’s state nuclear corporation, which oversees Rosenergoatom. Worn out equipment, human error and for under-preparation of NPPs to work in fire conditions contribute to this low installed capacity utilisation factor.