SEABROOK — The Nuclear Regulatory Commission has issued the first set of orders meant to prevent the kind of disaster that engulfed Japan's Fukushima Daiichi nuclear power plant last year, and Seabrook Station nuclear plant will be required to make changes in its safety systems.
According to Neil Sheehan, spokesman for the NRC's Region 1, the first two orders were issued to all power reactor licensees in the nation. The third order is for plants that use a system called boiling water reactors, which was the type of reactor used at Fukushima. The Seabrook nuclear power plant uses a different technology, called a pressurized water reactor.
The NRC's first order requires all power plants to develop strategies to mitigate the effects of "beyond-design-basis natural phenomena," such as earthquakes, tornados, flooding, hurricanes, etc., to address multi-unit events and reasonable protection of equipment needed to implement strategies. This particular order deals with external events resulting in loss of power and loss of normal access to the plants' "ultimate heat sinks," which is the body of water from which it draws water for cooling purposes and where it subsequently discharges that water at a slightly higher temperature, Sheehan said.
For Seabrook, the ultimate heat sink would be the Atlantic Ocean. Seabrook has long pipes that draw water from about a mile offshore.
Plants are being ordered to provide capabilities to supplement those already permanently existing in the facilities, should those already installed become unavailable due to natural phenomena.
"The strategies will add multiple ways to maintain or restore core cooling, containment and spent fuel pool cooling capabilities in order to improve the defense in depth of licensed nuclear power reactors," Sheehan wrote in his summary of the orders. "(It) also requires that the equipment needed to implement the strategies be reasonably protected."