In early December there was another round of isotope woes with NRU closing down for repairs but only for a relatively short period this time. Every time there’s a problem with creaky old NRU, AECL is criticised for its failure to replace NRU with the ill-fated MAPLE reactors. When NRU finally goes down for good there is no plan for future isotope production. As long as there are isotope supply problems, nobody is going to forget the MAPLE fiasco – it will keep on damaging AECL’s reputation in terms of building new reactors.
In my opinion, trying to extend the working lifetime of NRU past 2011 is not a good option assuming it continues to run until then. Patchwork repairs are not going to cut it and I suspect dismantling NRU in any serious way would reveal an increasing number of problems to be fixed. My feeling is that NRU needs to be completely rebuilt from the ground up to be safe in the future. This must involve replacing the vessel which would mean at least a year, but probably more like two to three years of downtime. If NRU were down for the years needed to refurbish it in a serious way, other arrangements for supplying fresh isotopes would need to be in place. (Since the isotopes have a very limited lifetime (short half-life) you can’t put aside a surplus supply for future use.) However, if such alternate arrangements for isotopes were indeed possible that begs the question why refurbish NRU in the first place? I think a realistic guess at the cost would be in the $1 billion range.
The economics of isotope production used to be very poor for producers. For example, some years ago it was said that nuclear medicine tests had a mark up of a factor of 100 i.e. the material for one test was supplied at $3 and patients were charged $300. It seems that for many years AECL (i.e. the Canadian taxpayer) subsidized medical radioisotopes for much of the world. Recently, it was reported that a US company is the distributor for Canadian isotopes in both the US and Canada and apparently gives no preference to Canadian patients. If true, that’s a real shame because I suspect there is still a Canadian subsidy of some kind.
A big problem for isotope producers is that the technetium is produced from a molybdenum fission product that comes from the irradiation of enriched uranium targets in a reactor (NRU in this case). This leads to a very messy waste problem. Once the molybdenum has been extracted all the other highly radioactive fission products in solution must be safely stored in large high-quality double-walled tanks. Safe means that care has to be taken that unwanted fission reactions don’t occur in these tanks. Every so often a new tank has to be built at a cost of many millions of dollars. All of this is technically possible and indeed has been done without serious incident for many years. The problem is that the wastes from isotope production have to be looked after for a very long time in a rather expensive manner.
An additional costly overhead is the security needed to safeguard the enriched uranium targets. This was going to be a double whammy with MAPLE which used (or was going to use) enriched fuel. (I read a report a few months ago that this fuel hadn’t been returned to the US in a timely manner; I hope this has now been done.) What company or university could afford to build a fortress-like complex and mount a round-the-clock security force to protect potential weapons materials? The answer, of course, is there are no takers.
Most of the cobalt-60 for cancer therapy and sterilization of medical supplies is or could be produced in power reactors and is not involved in the NRU issue. The problem concerns mainly the diagnostic tests based on technetium.
At the moment no one questions the assumption that large amounts of diagnostic medical isotopes will continue to be needed in future. Perhaps, the nuclear medicine doctors should moderate their consumption of isotopes and use them only when there is no other test available. I’ve heard it whispered by other physicians that there are indeed non-nuclear alternate diagnostic tests that are just as effective as some of the nuclear tests. If true, the number of nuclear procedures in the “nice to have” category could be reduced drastically. I can’t assess the truth of these assertions but they would be worth looking at by a non-biased (non-nuclear) group of doctors. This might go some way to solving the problem.
Many groups have probably tried to make business cases for isotope production. The fact that no other organization either US or Canadian has stepped forward to produce isotopes is a good indicator that there just isn’t a plausible business case. Furthermore, as a producer if your isotope supply system goes down you get pilloried by the nuclear medicine community, pressured by politicians, vilified by the press and generally accused of lack of humanity. It’s a Public Relations nightmare no sane company would want to get itself into however “attractive” they might consider the economics. That’s why there’s no ‘white knight’ on the isotope horizon with an easy solution.