An emergency exercise was conducted April 17, 2012, at the Seabrook nuclear power plant in New Hampshire. Federal regulations require these exercises to be conducted every two years for each nuclear plant. For these exercises the Nuclear Regulatory Commission (NRC) is onsite to evaluate how well the plant owner performs during the simulated emergency. And the Federal Emergency Management Agency (FEMA) is onsite to evaluate how well local, state and federal officials perform.
The exercise simulated an accident involving the large, rapid loss of cooling water for the reactor core. With reactor core meltdown imminent, workers declared a General Emergency, the most serious emergency declaration. This declaration required workers to notify offsite authorities so they could take appropriate steps to protect the public.
In preparing the summary of plant conditions to be conveyed to offsite authorities, an emergency coordinator asked for the wind direction from the low-level indicator on the plant’s meteorological tower. This tall tower has wind speed and director indicators near its top and also towards its base. The plant’s emergency procedures directed that the upper elevation indicator be used if a release of radiation was in progress and the lower elevation indicator be used otherwise. Although a release of radiation was already in progress necessitating that the upper indicator be used, the coordinator mistakenly requested readings from the lower one.
Workers compounded that mistake by mistakenly responding with wind information from the upper elevation indicator. Because a release of radiation was occurring at the time, their mistake could have been fortuitous since procedures required the upper indicator to be used during releases. But a third mistake undermined that fortune. The wind information from the upper elevation was recorded on the offsite notification form along with a note that “A radiological release has not occurred” when in fact a radiological release was occurring.
The NRC also identified that the company failed to detect the inaccurate information provided to offsite authorities during its formal critique of the exercise. The combination of the inaccurate notification and the associated failure to identify it during the post-exercise critique led the NRC to propose a White finding (the NRC classifies violations as green, white, yellow and red in order of increasing severity) for the violation.
The good news is that emergency exercises are conducted periodically to gauge how well onsite and offsite entities perform to protect the public from harm in event of a nuclear plant accident.
The bad news is that a fairly serious failure occurred during this exercise. Workers informed offsite authorities that a radiological release was not occurring when just the opposite was true. They blew the call about what was blowing in the wind.
This serious failure happened during a simulated exercise when stress levels are likely far lower than during a real accident and workers are not distracted with worries for their families and friends. In other words, decision-making during real accidents is more conducive to mistakes than during simulations.
“Fission Stories” is a weekly feature by Dave Lochbaum. For more information on nuclear power safety, see the nuclear safety section of UCS’s website and our interactive map, the Nuclear Power Information Tracker.