We put this question to Professor Swadesh Mahajan from the Institute for Fusion Studies at the University of Texas in Austin....

Swadesh: -   Yes.  The Yucca mountain site which was designed by the US folks  - of course not with a tremendous amount of enthusiasm - was expected to cost about $90 billion to $100 billion and it would’ve stored waste of about 40 years of operation of 50 to 100 nuclear reactors.  So if you really try to just divide it to all over, I think it adds just a few cents to the cost of electricity.

Chris: -   And, of course, you've got to factor in the environmental impact which is that we’re not releasing CO₂ as Ian Farnan said.  We’re sparing, for every ton of uranium, the equivalent in CO₂ terms, of a million tons of coal.

Swadesh: -   Right.  The very important thing of course is that it’s very difficult for us to be able to engineer too many such repositories with 10,000 to 200,000 years of lifetime.  So I think we should have a minimum number of them and if nuclear energy is going to have a renaissance, we really must destroy this before we store it.  Destroy as much as we can, if we reduce it to 10% or to 1%, the better it gets.  We are not going to be able to get a hundred Yucca mountains if the nuclear energy were to take off for instance, which is what will be needed if we try to store untreated waste.  That’s a political as well as a physical impossibility.  So we must destroy this.

We put this question to Professor Swadesh Mahajan from the Institute for Fusion Studies at the University of Texas in Austin....

Swadesh -   Yes, it can be, but when an actinide fissions inside a nuclear reactor, it produces about 200 MEV of energy.  That means a large amount of energy in a single reaction.  Anything that you might be able to get from the geothermal thing will be about a factor of 40 to 50 less.  So it will be a tremendous wastage of the actinide energy, just to get it in the form of geothermal energy from the waste.

Chris -   And also, presumably taking into account the infrastructure you would have to plumb in in order to recover the heat from the storage materials.  It just wouldn’t be financially or from a safety perspective, viable, would it?

Swadesh -   Too little energy for that much investment.

Chris -   They use what are called control rods - these are dense materials which, when dropped down into the reactor, soak up some of the neutrons that are produced by the nuclear chain reaction.  The consequence of that is that there are fewer neutrons left to bust open other uranium or fissionable nuclei, and as a result, the chain reaction is slowed down.  By putting the fuel rods in, or drawing them out, you can speed up or slow down the chain reaction, and therefore, you can affect how much energy actually comes out of the reactor.