 | Dysviz is a 61 year old guy from Okanagan, British Columbia, Canada. |
- Jul 2, 4:07pm
- In 2003, the Massachusetts Institute of Technology produced a detailed study of the future of nuclear power [MIT 2003]. This provides a wealth of data on the various types of nuclear fuel cycle that might operate in the future, and how much uranium these different fuel cycles consume. On the MIT analysis, the effect of switching from a 'once through' to a 'closed' cycle (where a mixture of thermal and fast reactors are used and the plutonium is recycled through fuel reprocessing) is to nearly halve the consumption of uranium per unit of energy produced. However, despite the fact that using fast reactors would reduce uranium consumption, and allow a greater proportion of the uranium resource to be utilised, no viable commercial design for a fast reactor has yet been produced. The major fast breeder projects have been curtailed by technical flaws, principally related to the problems associated with cooling the core of the fast reactor system. This impasse seems unlikely to change in the future given that the new (Generation III) reactor designs currently being tested, and most of the future (Generation IV) reactors that are being designed, are thermal not fast reactors.
The Lifetime of Uranium Resources
The nuclear industry often expresses the contribution of nuclear energy in terms of electricity generation, but it's more realistic to look at its contribution in terms of global energy supply. This is because, as fossil fuels become scarce [Mobbs, 2004], nuclear energy would have to displace the energy currently supplied by fossil fuels. Although nuclear energy provides 16% of the world's electricity supply [WNA 2005], recent estimates put the contribution to the world's total energy supply at between 6.1% [BP 2004] and 6.6% [UNDP 2000].
At the current level of uranium consumption (67,000 tonnes per year) known uranium resources (2.8 million tonnes of uranium) would last 42 years - a fact highlighted by the European Commission in their Energy Green Paper [EC 2001]. The known and estimated resources plus secondary resources (such as the military inventory), a total of around 4.8 million tonnes, would last 72 years. Of course this assumes that nuclear continues to provide just a fraction of the world's energy supply. If capacity were increased six-fold then 72 years would reduce to 12 years. This is because nuclear energy, in terms of global energy supply, must increase by a factor of four to eight to make any significant difference to the use of fossil fuels around the globe. Consequently the expected lifetime of the uranium resource would fall by a similar factor.
The actual lifetime of the uranium resource will depend upon the technologies adopted as part of any new nuclear capacity. New reactor designs are more thermally efficient (up to 45% to 50% rather than 30% to 35%) which could extend the lifetime of the uranium resource by a factor of 1.7. Introducing a number of fast breeder reactors, to increase the efficiency of uranium consumption, might increase the lifetime of the uranium resource by a factor of 2. Even so, taking these two factors together alongside a six-fold increase in capacity, the lifetime of the known and estimated uranium resource would still be less than 50 years.
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