Atomic Energy of Canada Limited will be unable to meet its planned deliveries of medical isotope molybdenum-99 for the week ending November 23, due to repair work being carried out at its NRU reactor.

AECL said, 20 November, that repair activities are underway on the fuel rod flask, which is used for fuelling and de-fuelling of the NRU reactor and for movement of other reactor components including molybdenum-99 rods.

There are no nuclear safety issues related to this activity.

The NRU reactor is expected to return to service "before the end of the current week," AECL said. It hopes to resume supplying molybdenum-99 to the market over the weekend.

NRU is one of six reactors responsible for supplying around 90-95% of the world’s medical isotope demand. The other reactors are Maria (Poland); Osiris (France); Safari-1 (South Africa); BR2 (Belgium) and HFR Petten (Netherlands).

In October 2011, the Canadian Nuclear Safety Commission renewed AECL’s operating licence for the Chalk River Labs, including the NRU, to 2016.

Photo: AECL’s Chalk River Labs, site of the NRU reactor