Update: Oct. 10/14 3:30 pm

The Canadian Nuclear Safety Commission has granted its approval for the research reactor to be restarted. The reactor will resume operations on Tues. October 14.

Oct. 10/14 – 11:30 am

McMaster is finalizing its plan to restart its research reactor after temporarily shutting it down Wednesday, Oct. 8th.

An error during a routine refueling prompted an unscheduled shut down.  There were no impacts to the public or the environment, no injuries to workers, and no observed damage to the fuel assembly.  The Canadian Nuclear Safety Commission has been notified and has been in communication with the University on its plan to restart the reactor.

A preliminary review has determined that an error occurred during a routine operation involving the fuel assemblies.  The assemblies are submerged under 27 feet of water within the reactor but one was not in a position connected to the reactor’s cooling system during the re-start.

The operator realized the error and immediately shut down the reactor and reported the incident.  No radiation or fission products were released. The reactor was then restarted and operated normally before being shut down for the day as scheduled. Upon further review, the University determined that approval from the CNSC is required for a restart. McMaster will proceed with restarting the reactor once that approval is granted. An application is expected to be submitted to the CNSC today.

Shutting down the reactor and restarting it are daily occurrences. During normal operations, the reactor is shut down every night and restarted each morning.

An internal investigation has begun to determine how the error occurred and to identify steps to ensure similar errors are prevented from happening again. The McMaster  reactor is a teaching and research facility. It does not generate electrical power and in addition to its research mandate is used to produce medical isotopes for the treatment of cancer and other illnesses.