Nuclear Power and Canadian Oil Sands

Extraction of oil from sand requires heat, lots of it. In fact, by far the most rapidly growing source of CO₂ emissions in Canada is the oil sands projects, which currently burn natural gas to obtain the heat required.

1. A reactor designed to replace natural gas heat and to co-produce electrical power could have an effective efficiency of at least 60%, double that of electricity only. This is because the reactor would be cooled with the sand stream instead of with water whose energy is then wasted. Electricity would be generated only on the portion of the cooling cycle that takes place above the temperature to which the sand must be heated. The resulting carbon footprint per megajoule would be the lowest of any other option in the world today, by a large factor. A proposed Toshiba mini-reactor could offer the nuclear option at smaller scale than a Candu reactor, matching the mobility of oil sands extraction better.

   The advantage to Canada's reputation and that of the oil sands projects would be huge.

2. Canadian Candu reactors have two unique advantages over all other designs. The first is that they can't melt down. If there is physical damage to the reactor unit, the heavy water drains away and the reaction is unsustainable. No human intervention or elaborate safety mechanism is required.

   Their second advantage is that they use unenriched uranium. If Canada were to instal an enriched fuel reactor, we have only two choices. One is to be totally dependent upon a foreign country for fuel. Given the disastrous consequences of losing access to fuel for electricity generators in a modern society, we are courting disaster with that choice. The only other choice is to build our own enrichment capability. That, of course, puts us on the route to potentially making bombs, the route that has aroused such concerns over Iran. Staying with unenriched fuel avoids both these problems.

3. There is a valid, long-standing public safety issue with nuclear power: the lack of a method of safe disposal of radioactive waste produced by reactors. Presently, such waste is stored on site in indoor water ponds. This method requires continuous human attention to maintain even minimal safety. It leaves the material open to capture and dispersal by an absurdly small terrorist group. It's a catastrophe waiting to happen, minute by minute.

   The United States is attempting to store waste at a central repository in such a way that it can be reused at some future time when technology permits. Not only has this evoked furious opposition from the jurisdiction chosen to accept most of the nation's waste, it ignores a fundamental truth of human civilizations. No civilization has ever lasted much more than a thousand years; most have lasted more like half that duration. The only way to handle waste that poses an acute danger to humans for hundreds of thousands of years is to dispose of it in a way that will survive a meltdown of civilization.

   There is such a way. It uses existing Canadian expertise, in oil well drilling. It not only permits each province to look after its own waste, it permits each major site to do so, thus removing the risks inherent in transportation of dangerous material. Put simply, it is to drill a hole two or more kilometers deep, as large in diameter as existing technology permits for low level waste, a smaller size for high level. Fill it to the one kilometer level with waste material prepared and diluted sufficiently in concrete cylinders that it is unlikely to reach critical mass now or in the future. Then, seal the top kilometer with non-radioactive material such as concrete and soil and start on the next hole. With such a geometry, there is no need for special measures to dissipate the heat produced by the decaying material. There are few places in the world where a kilometer of bedrock is insufficient to guarantee survival for a million years. Existing technology permits many separate bore holes to radiate out from a central point. A single drilling site, close to a major nuclear facility, could thus be used almost indefinitely.

   It's something we could begin now, to support a relatively quick and nationally significant reduction of Canada's carbon emissions. It would build exportable expertise that would permit others all over the world to improve the safety of nuclear electricity plants and to reduce their emissions. This would benefit Canada both financially and with a better climate for our future.

John Sankey