NRU Status Report No. 27

AECL provides update on NRU activities

CHALK RIVER, ON, Oct. 28 /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).

Vessel cleaning activities for the six sites requiring localized repair is complete and preparations are underway to conduct additional cleaning as necessary. This marks a critical step in the repair process as this cleaning prepares the repair sites for welding.

As part of the weld preparation, several samples of vessel material were "scooped" from the vessel wall. These scoop samples are presently undergoing analysis. This will provide AECL with a better understanding on the nature of the corrosion in the vessel and will allow final weld tests on actual vessel material.

Work continues on the training and qualification of welders who are preparing to execute the weld repairs. The weld repair team is preparing to transfer its training to Chalk River from the repair vendor's facility where they will continue to train using the remote welding tools and the full height mock-up in preparation for the actual in-vessel welding. The repair vendor is also preparing to ship the first series of welding tools to Chalk River later this week.

More information on the return to service of NRU is available at NRUcanada.ca, including a new video update from NRU Return to Service Project Director, David Cox . The video provides viewers with an overview of the complex work that has been completed to date including the inspections as well as the new tools being used to clean the inside of the reactor vessel. Cox explains that AECL is on the cusp of moving into the repair stage of the project, due largely to the speed at which the cleaning tool development was done.

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.

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.

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.

For further information: Dale Coffin, Director, Corporate Communications, Atomic Energy of Canada Limited, 1-866-886-2325