Reactor blackout fears spark post-Fukushima regulatory push

Among them were a set of new regulations to bolster U.S. reactors’ ability to withstand a prolonged blackout. The magnitude 9.0 earthquake that rattled the plant at Fukushima two years ago knocked out electric power to the entire facility. Backup onsite diesel generators were wiped out a short time later when a powerful tsunami caused by the earthquake hammered the Japanese coast.

Ultimately, the plant lost its cooling capabilities and a meltdown occurred.

The string of events “highlight the possibility that extreme natural phenomena could challenge the prevention, mitigation, and emergency preparedness defense-in-depth layers that are currently in place under the NRC’s regulatory framework,” NRC officials wrote in a notice announcing their plan to move forward with stronger regulations.

The notice, to be published in Wednesday’s Federal Register, is expected to be similar to a recommendation from an NRC taskforce created in Fukushima’s wake. They call for a minimum “coping time” of eight hours in the event of extended power loss throughout a power plant facility and 72-hours of coping for core, reactor and spent fuel pool cooling systems.

Nuclear plant operators would also be required to pre-stage resources that would support uninterrupted cooling in the event of an emergency.

It is unclear how much the proposed rules would cost, as estimates from a pair of two-unit plants ranged from $25 million to $43 million.

NRC is seeking comments from interested parties and members of the public, which can be made here beginning Wednesday.