NRU Status Report No. 22

AECL provides update on NRU activities

CHALK RIVER, ON, Sept. 23 /CNW/ - 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).

Data analysis continues on Phase II Non Destructive Examinations (NDE). Phase III analysis is complete and findings confirm there is no degradation of the upper portions of the NRU vessel wall. Development of the Phase IV NDE probe tool is complete and testing and training on the use of the probe is underway.

In advance of commencing the vessel repair process, portions of the interior surface of the vessel will undergo surface preparation and cleaning. Specialized cleaning tools developed by AECL and third-party vendors are undergoing functional testing at Chalk River Laboratories.

Efforts remain focused on completing fabrication, assembly and qualification of the repair tooling. Two welding tool units are now assembled and are being tested at the vendor's facility. AECL employees are being trained and qualified in the use of this equipment. A trial repair weld on a sample section of irradiated material using the vendor-supplied equipment was performed in the hot cell facilities located at Chalk River. Additional weld tests will be conducted.

Testing of the cleaning and repair processes and tools will continue using the full height NRU mock-ups now constructed at AECL's Chalk River Laboratories, Sheridan Park facility in Mississauga, Ontario, and at the vendor's facility. The work underway at all three locations involve more than 300 engineers, welders, technicians and operators working to return the NRU to service.

Guidance on the duration of the shutdown continues to be founded on the best evidence available, including the most up-to-date analysis of the inspection data, progress on repair strategies, and critical path requirements for restart after an extended shutdown. At this time, the application of the band weld build-up technique, and the number of identified repair sites, indicates the NRU will return to service during the first calendar quarter of 2010. Further guidance on a return to service date will be provided when more information becomes available.

Evidence collected to date continues to support AECL's view that the necessary vessel repairs can be made and that NRU will be safely returned to service.

The Canadian Nuclear Safety Commission (CNSC) safety inspectors continue to provide independent regulatory oversight of AECL activities at the Chalk River Site.

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

More information on the return to service of NRU is available at NRUCanada.ca.

For further information: Dale Coffin, Director, Corporate Communications, 1-866-886-2325