Atomic Energy of Canada Limited's (AECL) said 51 percent of the repair activities of the Chalk River, Ontario-based National Research Universal (NRU) reactor have been completed and is revising the return-to-service schedule.

“The latest weld repair was successfully completed on Tuesday, March 16 and has proven to be the most complicated and difficult repair undertaken to date,” said AECL. The vessel repair team is transitioning to the final repair sequence with two repair sites remaining. 

AECL said it is currently revising the return-to-service schedule based on the experience obtained from the latest repair, as well as recommendations stemming from the expert review conducted last week. The NRU reactor was earlier projected to return-to-service during the second half of May 2010.