The Unit 3 reactor at the Dresden Nuclear Power Station near Morris, Illinois is a boiling water reactor with a Mark I containment design that began operating in 1971. On June 27, 2016, operators manually started the high pressure coolant injection (HPCI) system for a test run required every quarter by the reactor’s operating license. Soon after starting HPCI, alarms sounded in the main control room. The operators shut down the HPCI system and dispatched equipment operators to the HPCI room in the reactor building to investigate the problem.
The equipment operators opened the HPCI room door and saw flames around the HPCI system’s auxiliary oil pump motor and the room filling with smoke. They reported the fire to the control room operators and used a portable extinguisher to put out the fire within three minutes. Read more >