For the last few days I’ve been putting down top soil and mulch in our garden and in addition to cursing the scientific illiterates responsible for the Ontario pesticide ban, I’ve been thinking more about the latest isotope supply crisis at NRU.
I’ve already written a couple of pieces in this blog about NRU and its problems but I’d like to come back to a theme that I first introduced in my January 2 post. Namely, that the current level of medical isotope use is not sustainable.
Do we really need to produce and use medical isotopes at the current level? It seems nobody has stepped back to consider this key question in a serious way. Instead all sorts of expedients to maintain the current production level are under consideration.
The first but least likely solution is to fix NRU. If it is possible to repair it in a reasonable time (doubtful), it’s only a short-term fix. There’s a reported rumour that some “nuclear engineers” want to restart the MAPLE project. After the laughter died down, I have to concede there is something in the idea at least in terms of regulation. Given the present climate in government, CNSC would only pretend to regulate a MAPLE redux probably by making appropriate noises of no substantive content. The likely consequence would be that these apocryphal engineers would be enabled to do some “light dusting” of the existing MAPLEs all the time waving the banner of isotope production and then start them up. I suppose that if there was a good containment structure around the MAPLEs, the consequences of an accident (the MAPLES were infamous for control rods that wouldn’t engage reliably) would not be so severe. But is there anything left to dust? Can the project be revived at this stage or are they too far down the decommissioning road?
There is also an innovative scheme to make some isotopes by photo-neutron methods at TRIUMF in Vancouver but it is only in the conceptual stage. I read that the University of Missouri wants to get into isotope production in a big way about five years from now. If that means they plan to irradiate enriched uranium targets (requiring heavy security) and store the highly radioactive fission product liquid waste, it’s a totally inappropriate activity for a university campus in my opinion. A criticality accident in the fission product storage tanks would result in many casualties in a densely populated area like a campus. Large scale isotope production should only be undertaken at an isolated nuclear reservation such as Chalk River or one of the US national labs such as Oak Ridge.
The few isotope production reactors in other countries are also old and in bad shape. It’s a good time to seriously consider whether society can or indeed needs to continue the present system of isotope supply. The current and future shortage mostly concerns technicium-99 which is extensively used in diagnostic tests. Do we really need so much technicium-99? The supply of the main therapeutic isotope, cobalt-60, is assured from power reactors and many other diagnostic and therapeutic isotopes with longer half lives are not so seriously affected.
Before we go running off to implement desperate measures such as reviving the MAPLEs or embarking on intensive isotope production on university campuses, we should have an authoritative and objective assessment by an independent internationally respected institution (e.g. the Harvard School of Public Health) that spells out what technecium-99 tests are essential in the sense that there are no other tests that can be reasonably substituted. This would tell us what production level is really needed as distinct from what is desired by the specialists in the field and would form the basis for a sustainable plan for isotope production.
It’s clear that the old days of abundant supplies of cheap isotopes are over and the former altruistic attitude that the Canadian taxpayer should subsidize the world isotope supply (or more accurately the middlemen in the value chain) is hopefully long gone. Rather we must insist on a realistic price for isotopes that reflects their real cost, doing so will also serve to regulate demand.