AECL reports that NRU reactor vessel repair activities continue to progress at the Chalk River Laboratories.
Repairs and non-destructive examinations remain at 24 per cent complete. Repair activities currently underway include the planned transition from the vertical welding tool to the horizontal weld equipment. Welders continue to perform reliability practice welds using the new horizontal welding tools in order to qualify to conduct each specific weld required for the remainder of the vessel repair. Repair efforts continue around the clock, seven days a week.
Evaluation of the data collected as part of the condition assessment of the reactor vessel is complete. Based on the assessment findings and input from third party experts, AECL has confirmed that the most effective repair method is a weld build-up technique applied to all of the identified repair sites. As a result, an extended band of weld build-up repair is not required.
More information on the return-to-service of NRU is available at NRUCanada.ca
. Evidence collected to-date continues to support AECL’s view that the necessary vessel repairs can be made and that the 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 inspection data, progress on repair strategies and critical path requirements for restart after an extended shutdown.
At this time, the application of the weld build-up technique, and the number of identified repair sites indicate the NRU will return to service by the end of March (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 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.
Source: AECL
