The world’s leading supplier of medical isotopes is back in business. In a statement released 7 July, the Canadian Nuclear Safety Commission has approved the restart of the National Research Universeral Reactor (NRU) at Chalk River, Ontario. Until it shut down last year, the facility produced more than half of the isotopes needed around the globe for medical applications, including molybdenum-99, which is crucial for diagnostic imaging of the heart, lungs, brain, liver and bone marrow.
The shutdown occurred on 14 May, 2009, following a power outage at the reactor site, 150 kilometres northeast of Ottawa. The detection of a heavy water leak hours later spelled the beginning of a protracted and complex repair operation. The reactor, built in 1957, has become a maintenance headache in recent years as well as a radioactive hot potato for Canada’s conservative minority government which has said it will not replace the reactor after NRU goes offline in 2016—against the advice of its own expert panel—and will instead seek other options for producing the isotopes.
The Commission’s decision today means the reactor can be reloaded with fuel and it is expected to begin making isotopes again by the end of this month. The decision follows a public hearing on 5 July to consider an application for the restart of NRU.
The decision is good news for thousands of patients and hospitals who depend on the isotopes which are produced in only a handful of reactors worldwide. The problems at Chalk River and other sites have led to a global isotope shortage at a time when the demand for medical imaging is growing. The molybdenum-99 produced at NRU is shipped regularly to facilities across North America where it decays into technetium-99m, a short lived isotope that is ideal as a radioactive tracer in the body for a wide variety of diagnostic applications. Other medical related isotopes produced at Chalk River include Iodine-131, Xenon-133 and high specific activity (SA) Cobalt-60, used in cancer treatment.
In a report issued on 16 June, the Canadian Institute for Health Information found a 22% drop in the number of nuclear medical tests performed in Canada between October 2008 and October 2009, in response to disruptions in isotope supply.