When Dominion power crews refuel North Anna Power Station’s Unit 1 reactor over the next few weeks, they’ll have some other work to do that’s related to the Fukushima nuclear disaster in Japan.
The scheduled refueling and maintenance outage for Unit 1—one of two reactors at the plant on Lake Anna near Mineral—began over the weekend.
Richard Zuercher, spokesman for Dominion’s nuclear operations, said in an email sent to plant employees on Monday that among the items on the maintenance to-do list is the installation of “mechanical and electrical tie-in connections for hoses and external power supplies” that could be used in an emergency that knocked out power and cooling water supplies to the plant.
A magnitude-9.0 earthquake and resulting tsunami seriously damaged the Fukushima Dai-ichi nuclear plant on Japan’s northern coast in March 2011. Nuclear fuel in three of the plant’s six reactors melted down, sickening some workers, contaminating the plant site and the surrounding countryside.
The improvements at North Anna—along with others scheduled or completed at the rest of the nation’s 100 commercial nuclear reactors in operation—are aimed at ensuring that emergency power and cooling water are available in the event of a disaster.
A spokesman with the Nuclear Regulatory Commission in Maryland said Monday that the Fukushima-related improvements are being done during refueling outages, and may differ somewhat from plant to plant.
Zuercher said those will be added to the work schedule, but would not extend the time of the current outage. Outages typically take about 30 days.
Inspections are also planned for Unit 1’s three steam generators, which produce the steam needed to power a turbine generator, which produces electricity.
North Anna has already done some similar, but unrelated, work. It replaced and added some seismic-monitoring equipment following a magnitude-5.8 Mineral earthquake in August 2011 that shut down the two reactors. That marked the first time a U.S. reactor was idled because of an earthquake.
Next up on the refueling schedule is Unit 1 at Dominion’s two-reactor Surry Power Station along the James River. That will begin as soon as the North Anna outage is over.
About a third of the uranium dioxide nuclear fuel is replaced during refueling.
Dominion plans its refueling outages for the spring and fall when electricity demand is lowest. North Anna’s reactors are refueled every 18 months, on a staggered schedule.
North Anna’s two reactors generate 1,892 megawatts—enough electricity to power 450,000 homes. Unit 1 began commercial operation in June 1978, and Unit 2 followed in December 1980.
Rusty Dennen: 540/374-5431