Like a Hurricane: Nuclear Plants in High Winds
August 23, 2011
New safety procedures were just announced for nuclear power plants during a hurricane.
On August 15, 2011 the Nuclear Regulatory Commission (NRC) announced an amendment to safety procedures in the event of a hurricane. The stated objective is to ensure that work hours are controlled and worker fatigue is managed in hurricane-like conditions both before and after the actual storm.
Nuclear industry The NRC notes that high winds make travel unsafe, and that those conditions could exist for several days before the threshold for an emergency declaration can be met. Also, the unpredictability of hurricane paths and the speed at which the hurricane approaches the nuclear plant contribute to whether the plant is in a declared emergency.
Industry had pointed out that all this means the plant may not meet the threshold of an “emergency” but may still be experiencing high winds. Further, after a hurricane has passed the amount of damage to the plant and the surrounding area may prohibit offsite personnel to return to the site to provide for shift relief. Thus compliance with work-hour controls is not possible in that scenario, even though wind conditions have subsided and the plant has exited its applicable emergency action level.
Nuclear reaction The NRC says it reviewed industry’s request and agreed that preparing sites for the onset of hurricane conditions is necessary to ensure plant and personnel safety and the common defense and security. Preparing sites for the onset of a hurricane includes sequestering enough essential personnel to provide for shift relief.
In Nuclear Power Plant-speak, an ‘Unusual Event’ can be declared when wind speeds reach a hurricane force of 74 miles per hour. However, unsafe travel conditions exist when sustained wind speeds are greater than 40 miles per hour*. Therefore, plant licensees may need to sequester site personnel well in advance of actually meeting the conditions for an ‘Unusual Event.’
The nuclear industry estimates that, on average for a hurricane situation, a single-unit site will require approximately 150 personnel on site, and a dual-unit site will require approximately 250 personnel – these are subject to the work-hour control requirements. In this situation, the licensee evacuates all other nonessential personnel from the site and expects them to return as soon as conditions allow.
Nuclear emergency During the time that site staff is sequestered -- and before the declaration of an emergency -- licensees would need to process many waivers for the work-hour controls to remain in compliance**. Even if it’s possible to address all the waivers, the industry believes this would distract the operations and security managers during a time when they need to focus on site and personnel safety.***
The Statement of Considerations final rule states that “plant emergencies are extraordinary circumstances that may be most effectively addressed through staff augmentation.” And in certain circumstances involving an emergency such as a hurricane, enforcement discretion may be available for plant staff augmentation that results in noncompliance. In fact, enforcement discretion before and after a hurricane may be granted when the certain conditions exist. Guidance manual EGM-09-008 is a recommended reference.
All guidance can be found on this page, very helpful: http://www.nrc.gov/reading-rm/basic-ref/enf-man/app-a.html
Wishing everyone a safe hurricane season.
* wind speeds as per the National Oceanic and Atmospheric Administration’s wind advisories issued via the National Weather Service (removes guesswork)
** see 10 CFR 26.205(d)(1) through (d)(5)(i)
*** once the emergency is declared, licensees need not meet the work-hour requirements specified in 10 CFR 26.205(c) and (d), as provided by 10 CFR 26.207(d)
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