Contrary to reports that the MAPLE reactors are the short-term answer to today’s global medical isotope shortage, there are significant technical and regulatory hurdles that require, in the best-case scenario, at least five to six years of intensive research and analysis before we can even consider bringing the MAPLE reactors on-line.
In May 2008, AECL announced the discontinued development of the MAPLE reactors. The main hurdle to completing the reactors was, and remains, resolving a power coefficient of reactivity (PCR) issue.
The MAPLEs were first-of-a-kind experimental reactors with technical risks known at the onset. The reactors were licensed by the Canadian Nuclear Safety Commission (CNSC) to operate with a small negative PCR. That means the core reactivity was to decrease as power increased. In June 2003, commissioning was put on hold when test data analysis indicated the reactor had a small positive PCR.
Extensive scientific analysis, consultations with the Korea Atomic Energy Research Institute and tests conducted between June 2003 and May 2008 could not resolve the PCR issue.
In addition, neither AECL nor its retained experts, including Brookhaven National Laboratory, Idaho National Laboratory and Argentinean INVAP, which recently completed Australia’s OPAL research reactor, were able to determine the cause of the positive PCR.
Beyond resolving the MAPLE PCR issue, the associated processing facility would need to be commissioned and the isotope product approved for use by regulatory authorities before these facilities could be brought on-line to supply medical isotopes.
Resurrecting the MAPLE project is not a quick fix to today’s global isotope issue.