NRU Status Report No. 42

AECL provides update on NRU activities

CHALK RIVER, ON, Feb. 10 /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).

AECL reports that NRU reactor vessel repair activities continue. The repair team completed its second horizontal weld repair and is preparing the vessel for the next series of repairs. The overall repair process began on December 12, 2009 . To date, 38 per cent of the repair activities and associated non-destructive examinations are complete.

This most recent repair marks the first time an in-vessel horizontal weld build-up was applied over a backing strip. This technique will also be used on the next weld repair site. Welders continue to perform practice welds using the horizontal welding tools in order to be qualified to conduct the next repair. The project team continues to work with third-party experts on finalizing detailed repair procedures for the next sequence of repairs.

In addition to vessel weld repair activities, work is being conducted to improve the overall reliability of key NRU reactor systems. For example, upgrades to the facility's process water system are now complete.

More information on the weld repair process and the work being done in parallel to prepare the NRU for restart can be seen in two new video updates posted to NRUCanada.ca.

Every effort is being made to return the NRU to service as soon as possible. However, the program to return the NRU to service is driven by safety, producing a quality repair, conservative decision-making and completing all of the necessary analysis before executing any of the repairs.

Guidance on the duration of the shutdown continues to be founded on the best evidence available, including the most up-to-date analysis of inspection data, progress on repair strategies and critical path requirements for restart after an extended shutdown. NRU's targeted return-to-service has been updated to April. Further guidance on the return-to-service date will be provided when more information becomes available.

The first medical isotopes will begin to be removed from the NRU for processing and distribution within 10 days of the reactor being returned to service.

The 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, AECL, 1-866-886-2325