The repair process of Chalk River, Ontario-based National Research Universal (NRU) reactor is progressing slowly and only 27 percent of the repair activities have been completed, delaying its reopening until April, according to Atomic Energy of Canada Limited (AECL).

The organization said that the overall repair process, which began Dec. 12, is proving effective but is progressing at a slower pace than originally anticipated and that welding equipment is undergoing modifications and testing for use in applying the horizontal repairs. 

AECL’s current schedule targets return to service by the end of March 2010. “However, if there are continuing challenges with the repair process, the NRU return-to-service schedule could extend into April,” AECL said.

“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,” AECL added.

AECL stated that 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.