First of all, the heavy water, in fact, is reusable. It's in a sealed tank, and the water costs about $300 a kilogram, so it's a very valuable commodity. The plan would be to simply keep recycling that heavy water and reusing it and processing it to remove any radioactivity that is in the water. It's worth doing that because of the high cost of the water.
In terms of the fuel, we in Canada have generated enough fuel waste over the last 50 years to fill a soccer pitch probably to a height of about four feet, so the amount of waste is actually very small and very manageable--about 6,800 cubic metres of spent fuel. One of the reasons it's relatively easy to manage the waste is that it's in small quantity and it's solid, and over time the radioactivity is decaying away, so the amount of heat that the fuel puts out is going away rather rapidly. Ninety-nine percent of the radioactivity external to the fuel has decayed away after the first year the fuel has come out of the reactor. So the radioactivity is decaying away with time.
With the new reactor, there's only one particular type of uranium in the fuel that actually produces the energy. It's called uranium-235. In the new reactor, we have increased the quantity of that uranium in the fuel so we can actually get three times more energy out of that fuel bundle than we can with the old fuel bundles. We have reduced the volume of waste for the amount of energy that we will actually get out of the fuel. In the longer term, I think what you're talking about is whether it's possible to recycle the fuel. The answer is yes. It is technically possible to take the fuel and recycle it back into the reactor and reburn it.
For example, in our existing CANDU reactors, we could take the waste from another type of reactor called a light water reactor, which has more fissile content in it at the end of its life than does the fuel that we start with. So it's an excellent fuel for burning in a CANDU reactor and for reducing the amount of waste and getting more energy out of it.
There are plans in the longer term to look at these advanced fuel cycles and look at recycling in the field.