Prairie Island plant off alert status day after mystery alarm

Officials at the Prairie Island nuclear generating plant near Red Wing, Minnesota, terminated its Notification of Unusual Event on Friday, a day after an unexplained fire alarm went off in the Unit 2 containment building.

The notification was terminated at 12:18 a.m. after plant inspectors conducted a thorough investigation of the plant and were able to positively confirm the site-wide absence of fire. Plant personnel also confirmed that there was no release of dangerous radioactive materials and, thus, no hazards to the public or plant employees.

A Notification of Unusual Event is the lowest of four emergency classifications established by the U.S. Nuclear Regulatory Commission (NRC) and indicates a potential reduction in the level of safety at the plant, but no threat to public safety.

Plant officials are working diligently to assess the containment building’s conditions and make any necessary safety repairs before returning the unit back to full operational performance.

One of two nuclear power plants in Minnesota, Prairie Island began operations in 1973. The generating station has two nuclear reactors manufactured by Westinghouse that produce a collective 1,076 megawatts of power. Units 1 and 2 are licensed to operate through 2033 and 2034.