AmerenUE’s Callaway Nuclear Plant, located near Fulton, Mo., was under an “Unusual Event” declaration from 10:21 to 11:15 a.m. today due to flammable gas detected in the Turbine Building in amounts that adversely affected plant operations. Unusual Event is a term established by the U.S. Nuclear Regulatory Commission (NRC) to describe a relatively minor occurrence at a nuclear power plant that could reduce the overall level of safety. At an Unusual Event, no action by the public is advised.
The gas detected in the Turbine Building was hydrogen, which is used to cool the electric generator. Plant officials say the building was evacuated as a precaution, and the Unusual Event declaration was lifted when testing indicated the hydrogen level had declined. The source of the hydrogen leak is under investigation.
Company officials say there was no release of radioactivity to the environment above normal operating limits, and the incident presented no danger to plant workers or the public. They added that all appropriate federal, state and local agencies were notified.
The plant was not operating at the time the leak was detected, because operators had shut the plant down earlier today to replace the power supply to certain plant controls.
An Unusual Event is the least significant of four emergency classifications established by the NRC. The other categories, in order of severity, are “Alert,” “Site Area Emergency” and “General Emergency.”
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CONTACT: Mike Cleary, 573.681.7137, or Susan Gallagher, 314.554.2175, both of AmerenUE