In three and a half years, the operating license of the National Research Universal (NRU) nuclear reactor at Chalk River will expire. The NRU is a hugely important piece of research equipment, arguably Canada’s most important and certainly among its most successful. It was instrumental in developing the CANDU reactor, which is the technology that is currently generating all of the output in the Nuclear row in Tables 1 and 2 in the left-hand sidebar on this page. As you can see, nuclear is by far the biggest electricity producer in Ontario. It comes with no air pollution, a vitally important attribute. The NRU also makes medical isotopes, the most important of which, by far, is molybdenum-99. Mo-99 is used in millions of medical diagnostic procedures every year, and most of the world’s supply comes from the NRU.

Extending the frontier of brain research using molybdenum-99 derived isotopes; in this case, investigating Alzheimer’s Disease. When Mo-99 production stops at the NRU reactor at Chalk River in Canada, the price of this priceless isotope will skyrocket. That is because the NRU makes Mo-99 more efficiently than any other production facility.
As things stand today, the NRU’s run as the biggest world supplier of Mo-99 will end in October 2016 when its 5-year operating license expires. What will happen then?
Again, as things continue as they are going today, the price of Mo-99 will go up. Medical professionals and millions of patients will then be forced to decide between paying that price or using less effective diagnostic techniques.
The price of Mo-99 will go up for a simple reason. The NRU is an extremely efficient machine for making Mo-99. It is efficient because it uses high-enriched uranium (HEU)—uranium that contains mostly the U-235 isotope—as target material for making Mo-99. U-235 splits easily into lighter fragments, one of which is the desired isotope Mo-99; so the higher the concentration of U-235, the more Mo-99 you can make.
Canada does not make HEU. So the operator of the NRU, Atomic Energy of Canada Limited, must use HEU that has been imported from the United States, which does have facilities that can make the stuff.
However, high enriched uranium (HEU) is viewed with suspicion by those entrusted with preventing nuclear weapons proliferation. If you have enough HEU you can, according to superficial and simplistic theory, make a nuclear bomb. In practice it is much more complicated: so much so that no nuclear weapons country in the world today has ever built a bomb by acquiring HEU in dribs and drabs from another country.
Nevertheless, the suspicion of HEU has led to an agreement among most countries of the world to stop using HEU.
No country views HEU with more suspicion than the U.S.; in fact, it was the U.S. that pushed hardest for the worldwide HEU phaseout, and continually threatens to embargo shipments to Canada, even though such a move would hurt its own health care industry by driving up the price of isotope diagnosis.
If the American position on HEU sounds paradoxical, given that the U.S. is our supplier of HEU, that is because it is paradoxical. The U.S. is the owner of one of the two biggest nuclear weapons arsenals in the world (the other owner is Russia). It also possesses the capacity to produce enormous amounts of HEU, and has no intention to give up that capacity.
It is not as if the U.S. is worried that Canada will use the small amounts of HEU it exports to Canada to secretly build a bomb. The NRU is under international safeguards, and there is no question that the the liquid wastes from isotope manufacture, wastes which still contain U-235, have been clandestinely used—AECL is shipping those liquid wastes back to the U.S.
So what is the U.S.’s problem with HEU? Its problem is Iran, North Korea, and Pakistan. Those three countries have all acquired the ability to make HEU, and the U.S. is trying to persuade Iran and North Korea to relinquish that ability (it has essentially given up on Pakistan).
And what do Iran, North Korea, and Pakistan do with HEU? The latter two make bombs, of course. And Iran hopes to make bombs.
You could be forgiven for wondering if the U.S.-led proscription against HEU is a case of closing the barn door after the horses have escaped. Iran, North Korea, and Pakistan already possess the capability to make HEU, and if you’ve been paying attention to world news over the past few years, you’ll know there is no indication they have any intention of giving up their HEU-production capability. The horses are not going back into that barn.
Which begs the question: what purpose exactly would be served by embargoing HEU shipments to Canada for medical isotope production? The embargo would end the NRU’s reign as the world’s premier source of cheap isotopes. Smaller, less efficient, high-cost producers would struggle to meet the world’s insatiable demand for Mo-99, thereby driving Mo-99 prices up, and consequently driving up the cost of health care in Canada, the U.S., and everywhere else. And what would the world get in return for that sacrifice? Nothing. The ban on HEU has had and will continue to have absolutely no influence on the weapons programs of Iran, North Korea, and Pakistan.
But I am a realist. I know that I can trumpet the absurdity of the HEU phaseout until I am blue in the face and Iran is accepted as an NPT weapons state, and the phaseout will probably remain in force. So how could Canada maintain its position as the world’s premier supplier of Mo-99?
There are two possibilities. First, the NRU could, against all expectations, receive another five-year operating license and the U.S. could continue supplying the NRU with HEU.
Second, we could make Mo-99 in CANDU reactors, the same ones that at 08:30 on Thursday, May 30 2013 were making more than 57 percent of Ontario’s electricity (see Tables 1 and 2). I have read a very interesting paper on this, and will discuss in an upcoming article. Stay tuned.
As Rod Adams has pointed out, the safest place to keep HEU or weapons-grade plutonium is inside an operating reactor. After some reactor operating hours, the fuel becomes a highly radioactive and degraded mixture of HEU or plutonium. While theoretically it might be possible to make a bomb from this used fuel, it is much more difficult than simply starting from scratch. So why bother?
I know the Maple reactors are – sadly – mothballed, probably for ever, but did their design also require HEU?
Originally yes and I’m not sure how decisive the additional technological challenges became when it “was decided” to use LEU. But I think the move to LEU factored into the decision to abandon the project.
You are correct that the US has a significant inventory of U235. It does not,however, have a capability to produce any more. The last enrichment facility capable of producing HEU was at Piketon, Ohio and it has been decommissioned.