Monday, July 02, 2007

Nuclear "Solution" Untenable.

Nuclear power is often hailed as a "CO2-free" form of energy, and a significant component of the energy mix that will be required to keep civilization running during the testing period post peak oil. The technology is not entirely free of CO2 emissions once all contributions are costed-in: making concrete and steel, building the plant itself, mining, milling and processing uranium into fuel rods and the ultimate decommissioning of the plant (presuming they will be safely and carefully taken apart, and not left to rot in a world with rather more pressing resource agendas by that stage). Estimates vary enormously as to exactly how much CO2 a nuclear plant will produce, and appear to range from 20 - 40% of the emissions that a conventional coal-fired power plant will produce during its lifetime [See Related Reading (2)] down to just about 3%, according to the nuclear industry (3). In the UK, the majority of electricity is produced from gas, but the share of the total taken by coal has increased to 30% during the past 2 years. Nuclear power contributes around 20% of the whole, which is a far cry from the almost 80% that the French rely on nuclear for.

Clearly, if the world is serious about implementing nuclear to reduce fossil-fuel based emissions incurred in electricity generation, a very large expansion of the sector will be necessary, as is the subject of a recent report which concludes that nuclear power plants must be constructed at a rate of four new ones every month if any appreciable difference will be made to cut human-induced CO2 contributions: the so called "fight against global warming".

It is inferred that this is impossible for logistical reasons, as stated: "A world-wide nuclear renaissance is beyond the capacity of the nuclear industry to deliver and would stretch to breaking point the capacity of the IAEA (International Atomic Energy Agency) to monitor and safeguard civil nuclear power." Now, apart from these problems of policing any such wholesale expansion in the number of reactors on the planet, there is surely the limitation that unless serious exploration for new sources of uranium is undertaken on a large scale too, including attempts to work poorer ores than the industry is used to, even at current rates of uranium consumption the resource will run-out in about 40 years. Thus, without a renewed supply of the basic fuel, or the employment of breeder reactors (using uranium or thorium) to make it go further, nuclear is not the long-term solution it is frequently purported to be. There is of course the issue of nuclear waste, although some pretty sensible strategies have been proposed, and I remember seeing a cartoon by "Friends of the Earth" which depicted a Roman Centurian and the caption "If the Romans had had nuclear power, we would still be guarding their waste."

The report by the Oxford Research Group has been published within a week of the World Energy Council (the global organisation of electricity producers - a bit like OPEC, maybe?) stated categorically that nuclear power had to be a significant part of the new energy mix both to counteract global warming and to guarantee security of (energy) supply. As a fraction, nuclear provides just 16% of the total electricity used on earth, and the demand for it is expected to at least keep in step with the growth in human population, which is estimated to reach 10 billion (it is now 6.54 billion) by the year 2075. The report concludes that in order to match this rise in demand for electricity, one third of all electricity will need to be made using nuclear by then, and to achieve this four new nuclear plants must be built each month for the next 70 years - making a grand total of 3,360 of them.

It is not clear, however, how the uranium (or thorium) fuel will be dug from the earth to run so many nuclear power plants, and it seems that the "solution" has created yet another "problem". Is it assumed that during the latter portion of that 70 years timescale, e.g. breeder reactors will be brought on-stream, or that more uranium will be recovered from as yet unknown sources, or that "unconventional" supplies of oil and gas will be "discovered" with which to construct and fuel the putative new generation of nuclear offspring? It always takes resources to extract resources and nuclear is no exception, needing supplies of conventional (fossil fuel) energy to underpin the various stages of construction, fuelling and decommissioning (allowing for my earlier caveat that this ultimately won't happen in a world with more pressing demands on its energy resources, whatever they may ulimately prove to be).

The report went on to say, "Unless it can be demonstrated with certainty that nuclear power can make a major contribution to global CO2 mitigation, nuclear power should be taken out of the mix." So there! Worldwide, there are presently 429 nuclear reactors in operation, ranging from a density of 103 in the US to just one in Armenia - the highly controversial Armenian Nuclear Power pant at Metsamor, which neighbouring countries and the EU want to see closed down. However, since it produces around 40% of the entire country's electricity, this is easier said than done. I visited Metsamor in 2001, returning to London amid high security on the morning of 9/11. There are 76 new reactors planned and 162 proposed as present blueprints stand, and so another almost three thousand is no mean ambition.

The report concedes that breeder reactors would be necessary, since they produce ("breed") more fuel than they consume, specifically by converting uranium-238 to plutonium-239. To realise the perceived 2075 secenario would necessitate the processing of around 4,000 tonnes of plutonium each year, which is clearly quite a headache in terms of security. Indeed, we may note that 4,000 tonnes of plutonium is around twenty times the current military stockpile of "weapons grade" plutonium, just to place the matter in context.

It is concluded that the probabilities are "large" that some of this plutonium would end up in the wrong hands and be used as a "dirty bomb" even if it was not used to make a sophisticated nuclear device. I suspect, however, that civilization will have fragmented into smaller communities long before then, and being a global phenomenon, the threat of terrorism will evaporate along with the world's supplies of oil and gas. In the face of a massive dearth in our conventional sources of energy, this will be the least of our worries.

Related Reading.
(1) "World cannot afford nuclear climate solution", by Jeremy Lovell, Reuters. news/newsdesk/L27192438.htm


Anonymous said...

A coal plant releases one tonne of carbon dioxide into the atmosphere for each megawatt hour of electricity it produces. Nuclear plants will no where come close to producing that much carbon dioxide. A claim that nuclear plants will produce 20-40% less carbon dioxide is incorrect and irresponsible.

Professor Chris Rhodes said...

Seems to be a contentious point that. I have appended the link that I got this from to the article. If you have some other information please send it on, and maybe I can write a posting about the realities of CO2 emissions from nuclear. I have no axe to grind either way, and am not anti-nuclear particularly. BTW, who are you?

Anonymous said...

In 1986 there were 65,000 nuclear weapons in the world. This is enough fissionable material to keep thousands or reactors going for a long time, without mining more uranium. Only 3% of the energy in Uranium is used before nuclear fuel is poisoned by fission daughter products. Reporcessing would allow the progressive capture of more and more energy. Breeding would open up the energy possibility even more. Using Molten Salt brreding technology would all for the efficient breeding of thorium, and the capture of all the energy potential In thorium and uranium. This would provide enough energy to last us for several thousand years. In 1941, no one had ever built a reactor. By the end of 1944, the United States had built 5. This was relatively a far greater challenge than building thousands of reactors today.

Professor Chris Rhodes said...

I'm all in favour of thorium and molten salt reactors - you can see some of my supporting articles and comments on the energyfromthorium blog (linked at top left of this blog). There are 40 - 50 years of uranium in reserves for fission, as things stand, and I agree breeder technology (which is what thorium involves too) is the only way to make those reserves last into the far future.

Since the US, Russia and the UK are actually revamping their nuclear arsenals now, do you think it likely that warheads will be turned into fuel rods? The world gets through about 65,000 tons of uranium each year and some 10,000 tonnes of reprocessed weapons-stock.

Some jester has posted on another posting peak oil is fake! I don't believe that and I think that running out of oil (then gas) which are used to extract and convert uranium ore into nuclear fuel will hit us before we actually run short of uranium. It takes resources to extract resources and that is, I think, the weak link in the nuclear fuel chain.

If you are the same anonymous as posted the first comment here, you can see I have posted a reference to a far smaller estimate of the CO2 output over the working lifetime of a nuclear plant for comparison. But when there are such disparities in projected values, e.g. 20 - 40% compared with 3%, I wonder which is the more reliable.

Keep sending your thoughts, as you seem to know what you are talking about! This blog is an evolving medium.


Chris Rhodes.

Anonymous said...

The amount of CO2 produced depends a great deal on how rich the uranium ore is. You're not going to find a consistent figure.

The figures you provide however are much more optimistic than some. Have a read of this one, which suggests that nuclear power may be no improvement over using fossil fuels:

It's backed up with lots of detail in the linked pages. It sounds well argued to me, but I am no nuclear physicist.

This one's also worth a read:

Professor Chris Rhodes said...

Dear Andrew,

I agree that getting a consistent figure is very difficult since each value depends on what exactly is included in the cost analysis.

I am aware of the Dutch work, which is berated by some in the nuclear industry and its supporters: in particular their claim that once the uranium ore gets of sufficiently poor quality, the amount of energy needed to extract and process it into fuel rods exceeds that which can be recovered from the uranium fuel.

Other analyses refute this, however, and suggest that even at a few ppm the EROEI would still come out on top for nuclear.

I see there is a paper going through US senate just now which proposes using thorium as a fuel rather than uranium.