Agency announces NRU reactor shutdown will continue into 2010

The Canadian nuclear reactor that satisfies more than half of demand of molybdenum-99 for medical nuclear imaging services in North America will not return to service until the first quarter of 2010.

Atomic Energy Canada Limited announced Wednesday that it was rolling back the estimated startup date for the National Research Universal reactor at Chalk River, ON. The reactor was shut down May 14 after a heavy-water leak penetrating its vessel wall was discovered. AECL initially estimated repairs would be completed in late 2009.

The shutdown triggered a widespread shortage of Mo-99, the precursor isotope necessary for the production of technetium-99m, a radioisotope used in a majority of nuclear medicine procedures. Most nuclear medicine departments in the U.S. and Canada were affected. The situation worsened in June when the High Flux Reactor at Petten, the Netherlands, another important source of Mo-99 production, was shut down for planned routine maintenance.

Dr. Jean-Luc Urbain, chairman of nuclear medicine at the University of Western Ontario in London, told Diagnostic Imaging during an Aug. 4 interview that his department was receiving only 40% of its usual Mo-99 consignment. As with many facilities in Canada and the U.S., his clinic had delayed noncritical imaging procedures and shifted to thallium-201 for nuclear cardiology and FDG PET for cancer diagnosis and staging.

AECL rolled back its reactor startup date to Q1 2010 after a nondestructive survey of the containment vessel identified nine sites of corrosive wall-thinning requiring repair.

Safety-related problems at the NRU reactor have been the cause of two extended medical isotope shortages since 2007. The current incident triggered calls in the U.S. for Congress to approve funding to reestablish a domestic source of Mo-99. The last domestic provider ceased operations in 1989.