Information Bulletin - Heavy Water Spill

Chalk River Information Bulletin

(2010 April 27) The following information bulletin is in accordance with Atomic Energy of Canada Limited's (AECL) ongoing commitment to voluntary public disclosure of events related to the Chalk River Laboratories (CRL).

During activities to refill the NRU Main Heavy Water Circuit in preparation for returning the reactor to service, approximately 42 litres of new inventory of heavy water was spilled within the NRU facility.

The spill was immediately detected by NRU’s leak detection equipment, and refill activities were halted. The source of the spill was located at a flange on a valve in one of the reactor’s heavy water heat exchanger rooms.

The heavy water was collected with absorbent material and will be reclaimed for future reuse. Approximately 7 litres of the heavy water evaporated through the facility’s ventilation system. This airborne release was well below regulatory limits for tritium release.

Operations staff is conducting a thorough examination of connections in the Main Heavy Water Circuit to prevent reoccurrence.

This event has been reported to the Canadian Nuclear Safety Commission (CNSC).

There is no threat to workers, the public, the environment or nuclear safety related to this event.

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Patrick Quinn
Manager, Site and Community Affairs
Chalk River Laboratories
(613) 584-8500