NRC Eyes Changes to Address Station Blackout Conditions
The ANPRM published March 20, to ensure licensees are prepared for the potential loss of all AC power at a nuclear power plant, stems from the March 2011 Fukushima Daiichi disaster.
The Nuclear Regulatory Commission has published an advance notice of proposed rulemaking as it considers revised regulations that address station blackout, which is the total loss of on-site and off-site alternating current (AC) power to a nuclear power plant. NRC said it seeks public comments on specific questions and issues for this scenario.
This is coming up now because the task force formed after the Fukushima Daiichi nuclear power plant disaster in Japan in March 2011 proposed a station blackout recommendation, which the National Resources Defense Council then endorsed in a petition for rulemaking that would require new and operating reactor licensees to:
- Establish a minimum coping time of eight hours for a loss of all AC power
- Establish the equipment, procedures, and training needed to implement an "extended loss of all AC" coping time of 72 hours for core and spent fuel cooling and for reactor coolant system and primary containment integrity as needed
- Preplan and prestage off-site resources to support uninterrupted core and spent fuel pool cooling, and reactor coolant system and containment integrity as needed, including the ability to deliver the equipment to the site in the time period allowed for extended coping, under conditions involving significant degradation of off-site transportation infrastructure associated with significant natural disasters.
NRC is asking for comments within 45 days (Docket ID NRC-2011-0299, www.regulations.gov). The contact for more information is Timothy A. Reed in the Office of Nuclear Reactor Regulation, 301-415-1462 or Timothy.Reed@nrc.gov.
The Fukushima Daiichi plant's three operating reactors lost off-site power following the March 11, 2011, earthquake nearby, and five of its six units experienced station blackout after tsunami waves struck the site. One air-cooled emergency diesel generator stayed on in the sixth unit, according to NRC's ANPRM.