NRU Status Report No. 40

AECL provides update on NRU activities

CHALK RIVER, ON, Jan. 27 /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 the NRU reactor vessel repair activities are currently focused on preparation work in advance of the next series of weld repairs. The overall repair process commenced on December 12 . To date, 29 per cent of the repair activities are complete.

Difficulties experienced in deploying the specialized tooling required for the current sequence of repairs have been addressed and welding activities are scheduled to resume later this week.

Welders continue to practice repair welds in the NRU mockups and the project team has made progress in completing stress analysis for this repair sequence. This testing also minimizes the possibility that activities undertaken in the reactor vessel could cause damage to the reactor. The project team continues to work with third-party experts to optimize the repair strategy for the third and last sequence of weld repairs.

To help offset schedule delays, return-to-service activities are being brought forward in the schedule. Activities such as the commissioning of the Fuel Rod Flask, a major component required to add fuel to the reactor, are in progress.

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

In light of the continuing technical challenges, the project team has reviewed the return-to-service work plan. As a result of the review, 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.

More information on the return-to-service of the NRU is available at NRUCanada.ca, including a new video update from NRU Return-to-Service Project Director, David Cox . In his update, Mr. Cox provides an in-depth description of how several millimetres of aluminum thickness is being applied to the vessel wall at each repair site to provide both additional structural strength to the vessel wall and sufficient corrosion allowance.

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