Irecently attended a thorium conference in Cape Town hosted by the South African Institute of Mining and Metallurgy.
There is a concerted effort to revive the idea of thorium as a better and ‘greener’ alternative to uranium. I would not classify thorium as ‘green’, but the experts tell us that it has four key properties that make it superior to uranium: you need less thorium to produce the same amount of energy, compared with uranium; thorium is more abundant than uranium (three to four times more); thorium cannot be used to make bombs because of its ‘proliferation resistance’ property (except that it does generate fissionable materials, such as U233, and its radioactive waste is said to be less dangerous and has a shorter half-life than uranium waste.
Thorium’s history confirms why it was never an option for atom bombs. There were thorium reactors in the 1950s and 1960s; US and German scientist worked on the reactors. The reactors were actually functional but not commercially available. By and large, these reactor programmes were abandoned for uranium-based reactors because the latter could be used to generate energy and to produce weapons-grade uranium and plutonium.
India has a big thorium reactor programme and seeks to be a leading country in thorium development. You will not hear much about it because it is quite a secret, following a pact India signed with the US during the George W Bush era. India never signed the Non-Proliferation Treaty, despite having nuclear bombs, which it actually tested at some point. So, India had to get the US’s nod for it to access critical technology from the Nuclear Support Group for its civilian nuclear programme. India has large deposits of thorium and this explains its urgency to develop thorium technology.
Commercially developed thorium reactors may not be very far off. There are two major developments as far as this story goes: Norway, in partnership with other countries, is racing to develop a commercially viable thorium fuel cycle to replace uranium-enriched rods for current light water reactors with thorium fuel, and India – and perhaps other countries as well – is looking at fourth-generation nuclear reactors as the next revolution in nuclear generation with many more modular formats similar to what we tried for the pebble-bed modular reactor (PBMR).
Norway’s commercialproofing can be done in the next five years at substantially lower costs than those associated with the PBMR. I am not a supporter of nuclear power but, clearly, the Norwegians, who do not even have nuclear power, have worked out a very strategic niche and role for themselves. We should apply their ‘nose’ for strategic niches to the development of cutting-edge renewables technologies.
Our nuclear industry should learn the hard lesson about developing new nuclear technologies: going big, bulky ends up being slow and costly. India’s thorium reactors are still a very long way from being proven. When the Indians decide to be less secretive, they may spring a surprise on us or they may come out clean on how foolhardy their whole endeavour may have been.
From what we know, India is looking at having a fast-breeder thorium reactor of about 300 MW up and ready by 2013 or so. We will wait and see whether this really happens.
South Africa also sits with large deposits of thorium. In fact, we have a mine called Steenkampskraal – which was last operational in the 1950s – which produced some thorium that was probably supplied to the US thorium reactors.
Steenkampskraal is being reopened, but not for thorium production – it has one of the largest deposits of high-grade monazite, an ore that contains generous amounts of thorium and rare-earth oxides (REOs). Monazite is also a waste product of mineral sands mining. So we sit on all of this ‘waste’ which is thought to have great value if commercial use for thorium can be found. This explains the big interest in thorium from the South African side.
The irony is that green technologies which use all sorts of REOs could end up making thorium as an alternative to uranium a viable option. Even digging REOs for green technologies is not without its problems and challenges. This is because an increase in the volumes REOs mined results in an increase in the radioactive waste pile, which goes unnoticed by the environmental lobby linked to the mining or disposal of monazite. I do not know the exact levels of radiotoxicity and the extent of the problem, but it does exist.
I am personally sceptical about thorium for now. I suppose the same things that bug me about nuclear energy would play themselves out in my thought processing of thorium.
These would be issues of waste of public funds, safety, the disposal of radioactive waste and the interest of big money in sucking the public purse for profit. But, as I am a great fan of open-mindedness, I will keep my mind open for now. However, as is always the case, as you go along the journey of discovery, you will find that you have more questions than answers.