Isotope crisis reactor back under regulation

14 April 2008

The Canadian Nuclear Safety Commission (CNSC) has resumed oversight of the National Research Universal (NRU) reactor at Chalk River after the expiry of an exceptional government bill which had overruled its authority.


On 12 December 2007 a bill was passed by parliament to stay CNSC's authority on certain specific part of NRU's coolant system for 120 days in order to allow the reactor's owner and operator, Atomic Energy of Canada Ltd. (AECL) to restart the unit sooner. This was necessary, the government had argued, to safely bring NRU back into operation as soon as possible in order to end the shortage of medical isotopes that was beginning to threaten Canadians' health treatment.


The reactor, which supplies about one third of the world's radiotherapy isotopes, was forced to stay shut down after CNSC staff objected to the slow pace of AECL's work to upgrade certain safety systems in November. CNSC said AECL had been in violation of its licence to operate the reactor.


Connections from two heavy water cooling pumps to a new emergency back-up power supply were to be made, but this work would take so long that medical isotopes would run out. AECL insisted the reactor would be safe to operate on an interim configuration with just one of the pumps connected to the new supply, while CNSC insisted all the work should be complete before any restart. It was CNSC's authority on the other as-yet unconnected pump that was stayed by the government bill. The regulator continued to oversee other matters at the facility.


As the medical isotope supply situation grew worse, the government intervened with an emergency bill which exempted NRU from CNSC oversight and made it legal for AECL to restart in the interim configuration. Natural resources minister Gary Lunn then sacked CNSC president Linda Keen from the top role, although she stayed on as a commissioner.


Now, "the reactor is operating safely and CNSC and AECL staff have agreed on a way forward through more effective regulatory compliance to ensure that such a situation does not reoccur," according to Keen's replacement, Michael Binder. "Upgrades relating to the connection of the emergency power supply to two of the NRU's main cooling pumps are fully operational," he confirmed.


A directive to CNSC to 'take into account the health of Canadians who, for medical purposes, depend on nuclear substances produced by nuclear reactors' had been issued by government shortly before the CNSC was overruled. Binder said the directive "will be part of our deliberations in all future CNSC licensing decisions."