A new generation of nuclear reactors is now vehemently "on" according to the U.K.'s Prime Minister, Tony Blair. There has been some conflict of opinion about this issue: on the one side is Professor Sir David King, the government's Chief Scientific Advisor, who believes that nuclear is the correct option to avoid CO2 emissions ("reduce" is a more accurate word than "avoid"), while Sir Jonathon Porritt, who heads the government-incepted Sustainable Development Commission panel is, on balance, opposed to the idea. It would appear that the coin has fallen on the face of nuclear. Indeed, at face value, there is some sense to the idea. Nuclear currently provides around 18% of Britain's electricity, and all but one (Sizewell B) of the present generation of reactors are due for decommissioning by 2025. If we don't replace them, then what?
On reading through yesterday's newspapers (The Guardian in particular) I don't see any mention of what type of reactors are to be implemented, and this is undoubtedly a key point. If the world continues to use fission reactors (which "burn" uranium enriched in the isotope uranium 235) it will run out of uranium within 50 years, and long before then, the mining, milling, extraction, enrichment and fabrication of nuclear fuel rods will become counterproductive in terms of the quantity of fossil fuel required to run the gamut of these processes. i.e. Nuclear will produce more CO2 by burning more conventional fuel than it generates in terms of electricity: a good case for cutting out the middle man, in this case "nuclear".
As an alternative strategy, the known reserves of uranium could be significantly stretched-out by a factor of about 60 (i.e. to last 3,000 years as a simple sum), if it were employed in fast breeder reactors, which convert the majority uranium isotope (238) into plutonium by in-situ neutron irradiation. However, this will render vast amounts of plutonium available: a wonderful weapon for terrorists or anyone else with a grudge. The one benefit of this method is that there will be less "depleted uranium" available for fabrication into armaments and missile warheads, which is what is done with the left-over uranium, after uranium-235 enrichment. Put another way, the uranium-235 is extracted by centrifugation of the gas uranium hexafluoride, since it is lighter than the uranium-238 version, which is hence depleted in uranium-235.
The enriched and depleted uranium hexafluoride are both hydrolysed (reacted with water) to form uranium oxide (U3O8). The uranium-235 enriched U3O8 is then used as a nuclear fuel, while the depleted (or uranium-238 enriched) U3O8 is reduced (a chemical term meaning "deprived of oxygen") to metallic uranium, a very dense material (weighing in at 19 grams per cubic centimetre; 1.6 times the density of lead) that either blocks a punch when made into the housing of a tank, or packs one when fabricated into the warhead of a missile.
In the latter case, the effect is particularly charming, since a depleted uranium missile tears its way into a tank, heating up in the process to around 1,000 degrees C. whereupon the metal ignites and exposes the enemy tank crew to a fireball of burning metal. Bye-Bye. So, fast breeders might discourage this eventuality.
It is not just the replacement of the contemporary nuclear power stations that is envisaged, however, since Professor King believes that we could realistically provide 40% of the U.K.'s electricity using nuclear. Clearly if the whole world were to follow this example, it would run out of uranium in just over 20 years, so I presume it is "fast breeder" technology that is intended. The French are committed to fast breeders in the long term of their nuclear power programme. We should heed their views, since France with its very limited natural resources produces almost 80% of its electrical power using nuclear, and are sensibly and well aware of the limitations of uranium fuel. Currently, all European countries, including the U.K., buy their uranium from Russia.The U.S. gets its supply from Canada - along with much of its oil. So, CO2 emissions aside, there is the issue of "security of supply". Since the U.K. has no reserves of uranium, it must depend on good relations between Europe and Russia to provide it.
Naively, one might speculate that supply is not "secure" of any resource not native to one's own shores; however, Europe has two years worth of uranium in stock, and it is presumed that if anything were to go awry politically, this would buy sufficient time to find a new source. Canada? The same concern applies to supplies of oil and gas, and the U.K., having used-up its own North-Sea provision and sold the rest off, is now a net importer of these precious fuels.
It is all rather worrying. Increasingly we are dependent on energy stocks that are honed from politically maverick regions of the world. Surely, a more appropriate strategy is to provide from our own resources - those of nature, sun, wind and water - but only having first eliminated all unnecessary and wasteful practices, such as those of draughty buildings and profligate transportation. Recently, the Oxford (university) Environmental Change Institute concluded that we could provide 20% of our electricity in the U.K. using "sea" power, i.e. tidal stream and wave power, which almost exactly matches the amount we are seeking to generate via Mr Blair's new generation of nuclear power stations. So, why don't we do it?