NRC seeks input on new nuclear design

WASHINGTON DC - The U.S. Nuclear Regulatory Commission NRC said it was seeking public comment on the proposed certification of General Electric-Hitachi Nuclear Energy's Economic Simplified Boiling-Water Reactor ESBWR design for use in the United States.

This is just one step in a long certification process started in 2005, but it comes just weeks after an earthquake and tsunami seriously damaged the Fukushima Daiichi nuclear power plant in Japan.

Following a radiation release at the plant in Japan, nations around the world, including the United States, started reviews of their existing and proposed new nuclear fleets to make sure the reactors are safe.

The NRC said it planned to make a final decision on the ESBWR design in late 2011. But a spokesman at the NRC could not say whether the events in Japan would change that schedule.

To date, the NRC has already certified four designs, three by Westinghouse — the System 80+, the Advanced Passive 600 AP600 and 1000 AP1000, and the General Electric Advanced Boiling Water Reactor ABWR.

The NRC is also expected to certify a modified version of the AP1000 in the autumn of 2011.

More than half of the applications for 26 new reactors already filed in the United States referenced the amended AP1000 design. Westinghouse is majority owned by Japan's Toshiba Corp and engineering firm Shaw Group Inc.

In a release, the NRC said the public had 75 days to comment on safety issues, among other things, for the proposed new ESBWR design.

After the NRC certifies a design, a utility applying with the NRC to build a new reactor can reference that design and would therefore not need to submit safety information on the design as part of their application.

At least one company, DTE Energy Inc, has already told the NRC it wants to use the ESBWR design in a new reactor proposed for Michigan. DTE however has said it has not made a final decision to build the new reactor.

GE-Hitachi submitted an application for certification of the ESBWR with the NRC on August 24, 2005.

The ESBWR is a 1,594-megawatt electric, natural circulation reactor. It includes passive safety features that would cool the reactor after an accident without the need for human intervention.

The disabling of the cooling system at the Daiichi reactors was a big part of the problem in Japan since it allowed the reactor cores to heat up and partially melt the fuel, releasing hydrogen gas that resulted in explosions that damaged the reactor's outer buildings.

Some of the passive safety systems on the ESBWR include enhanced natural circulation via a taller reactor vessel, a shorter core and improved water flow through the vessel an isolation condenser system to control water levels and remove decay heat while the reactor is pressurized and a gravity-driven cooling system to maintain water levels when the reactor pressure drops.