The scientific briefing with Luke Boulter
In July 1945 the US tested a bomb with an explosive impact equivalent to 200,000 tonnes of TNT: the bomb named Trinity was the first (not so small) step in nuclear technology. Now several hundred thousand tonnes of plutonium and enriched uranium are available, and 27,000 atomic bombs are stored away. Having said this, 16% of the world’s energy supply comes from nuclear power. It is of massive benefit to people; the question is, at what cost?
In the last fortnight the World Wildlife Federation-UK (WWF-UK) has produced a report which states in no uncertain terms that the UK can meet its energy demands and reduce CO2 emissions in line with the Kyoto protocols without the need to use nuclear technology. With some small tweaks to current government policy it would be feasible to reduce 1990 carbon emissions levels by 40% by 2010, and to further reduce these levels to 55% by 2025. Great, you might think, and this is true: the notion of replacing our carbon based energy sources with nuclear and renewable fuels is a positive one. However, there are some unavoidable issues concerning the use of unstable fuels to power our country.
The most compelling argument against the widespread use of nuclear power for energy is not one of safety; it is the longevity of radioactive isotopes that the main problem. The decomposition of an isotope (nuclear fission) is measured in half-lives, that is, the amount of time it takes for a sample of material to reach half its activity. Uranium-235, the Uranium isotope that is used in nuclear fission, has a half-life of 760 million years, and upon decomposition Uranium becomes plutonium.
In 1995 it was reported that Japan, one of the world’s key proponents in nuclear fuels (40% of the country’s energy comes from nuclear reactors) had a surplus of 4.7 tonnes of plutonium. It is these stockpiles of nuclear waste that are causing massive concern in nuclear countries. This issue is so pertinent that many governments have set up councils to deal with the situation that is looming on a none-too-distant horizon.
Even with these advisory bodies on nuclear disposal at hand there is still much confusion and some confrontation as to what should be done with the waste from our energy production. The UK’s Committee on Radioactive Waste Management (CoRWM) has taken three years to come to one conclusion: that nuclear waste from the UK should be buried, an idea that has been proposed three times in the last 30 years and has been rejected each time.
The proposal is simple: bury the UK’s 400,000 cubic meters of radioactive waste between 300m and 2km below the earth’s surface in stable geological formations. This may sound extreme, depending on your point of view, but there are massive implications for the countryside if we do bury our nuclear litter.
The area in Ukraine where Chernobyl nuclear reactor number 4 once stood remains to this day extremely radioactive and entirely uninhabitable, and the long-term implications of that one explosion are still uncertain 20 years on, with a predicted 60,000 deaths from the after effects of radiation. The depth that the UK wishes to bury its nuclear waste is sensible, but for how long can this problem have a layer of earth neatly placed atop it? How about one thousand years?
In practice these wastes are no more dangerous than any others: they are, if deactivated and shielded, perfectly safe. In fact, for a sample of Uranium to reach one thousandth of its activity takes less than 100 years, and after a few thousand years its radioactivity has reduced to levels similar to that when it is mined. However, there is a horribly ironic twist to the story. The UK Environment Agency has suggested that rising sea levels, a consequence of global warming, will jeopardise many of the nuclear waste sites around the world within the next 500 years, making them impossible to use for storing nuclear waste.
So, what are the alternatives to Uranium, if we decide that this is too much of a long term comittment for a short term advantage? There are the obvious options to expore: an increase in wind farms and hydro- and solar- based energies. The success of these types of energies can be seen in Canada, which supplies more than 50% of its energy requirement in this way.
Another option is to use nuclear fusion. Up until now nuclear power has resulted from the decay of isotopes, but in 2005 France won an exciting bid to build a fusion reactor and attempt to make the world’s first source of clean, safe and almost infinite energy. The process relies on the fusion of two hydrogen atoms to produce helium; this mechanism expels a lot of energy without creating a lasting nuclear legacy. The only problem facing this plan is that the research has lasted half a century and cost $20 billion, no small bill. It is disheartening, then, that no massive advancements have been made, as this method requires a massive magnetic field, and plasma hitting temperatures that have never been achieved before.
This nuclear dream could become reality over the next half a century, but living in the here and now there is no effective energy source which will not, in some way, affect us or the environment. Carbon-based emissions must be reduced, but whether a progressive takeover by nuclear is a good idea, only time and environmental security will tell.