Nuclear Fusion to Power the World?
Posted by jennifer, July 1st, 2005 - under Uncategorized.
Tags: Energy & Nuclear
Every so often I am asked to be a part of Friday morning’s panel of guests at the local ABC radio station. Guests nominate their ‘big issue’ for the week and discussion follows.
I am on tomorrow (it will probably be today by the time I post this) and I have been surfing the net and reading the papers thinking about what I might nominate as the ‘big issue’ in the morning.
The event that seems to have passed pretty well under-discussed is the announcement in Moscow on Tuesday to build a $16 billion nuclear fusion reactor in the south of France.
The advantage of nuclear fusion over the current uranium-dependent nuclear fission plants is that there is no radioactive waste. Both fission and fusion are greenhouse neutral.
I gather that the nuclear fusion rector has been on the drawing board since the early 1980s and since December 2003 negotiations had been deadlocked over where to build it with the Japanese (one of six countries involved in the project others are Russia, South Korea, US, China and European Union) insisting that the reactor be
based in Japan.
Anyway on Tuesday it was finally agreed that the site would be Cararache, near Aix-en-Provence in the South of France. Cararache apparently already has 18 nuclear installations and is already a centre for research on magnetic fusion.
I understand that nuclear fusion involves the forcing together of atomic nuclei, typically hydrogen atoms, under high temperature and pressure potentially through the creation of magnetic cages with strong magnetic fields which prevent the particles from escaping. It is claimed the technology can potentially deliver abundant cheap energy whose main by-product is water.
The sun is powered by nuclear fusion. While the concept is not new, this appears to be the first big investment in developing the technology for commercialization. With all the discussion about greenhouse and the need to reduce carbon dioxide emission, the price of oil, fear that oil will run out, and the opposition to power stations based on traditional nuclear fission technology, it seems surprising that this announcement has generated so little public discussion.
Jennifer – This reactor is not an operational reactor but a continuation of the experiments that have so far failed yield any usable power.
Some people view the whole project as a waste of money as we already have a functioning fusion reactor at a safe distance already.
Also the experiment does not use hydrogen. I am pretty sure it uses tritium which is a very rare isotope of hydrogen. Current experiments do not even envision the use of duterium-duterium fusion as this is just too hard. With the primitive state of fusion at the moment tritium has to be used.
This is probably why it did not garner much interest.
You’re painting a very rosy picture of fusion energy, with some inaccuracies. For example, it’s not true to say that it doesn’t produce nuclear waste.
I wouldn’t count on it being a reliable power source for some time, if ever, either. They’ve been trying for over 50 years to produce industrial fusion power with no success.
I wouldn’t be surprised if during my lifetime (assuming I’ve got about 50 years left) the only viable form of fusion energy continues to be solar. But good luck to the ITER consortium. Pity Australia isn’t part of it.
Many billions of dollars has already been spent on this technology without it producing more power than it consumes. Optimistically it will be decades before this can be a reliable source of energy.
Graham, What sort of waste is produced by nuclear fusion?
Nataraj, So you think it is a question of time – but that one day it might be a reality, electricity from nuclear fusion that is?
Jennifer – because the current fusion experiments use tritium the components inside the the magnetic bottle get bombarded with neutrons causing them to become radioactive. This would have to be disposed of when the reactor was de-commisioned.
Yes, a promising technology that has been promising, but not delivering, for decades.
I wouldn’t want to see research stopped, because viable fusion power would create huge opportunities. But it would be a bad idea to make plans based on its imminent existence.
Any working fusion reactor is likely to make its components radioactive, whether or not its fuel is. This is already a problem with particle accelerators.
There’s tritium, apparently, and whatever material the reactor is made of. Depending on how you confine the reaction there are different possibilities for the construction materials. Carbon can possibly be used, and vanadium. Half lives are less than those for the materials produced by fission, but you are still producing radioactive waste which has to be disposed of in some way.
Some information on what is happening is at
http://www.WantToKnow.info/050629nuclearfusionreactor
Clearly a long term project and we all have to wait to see the outcome.
As for those of us involved in Plasma science, Fusion and Fission are non starters.
The Sun is better explained as an a Anode in a cosmic scale electric circuit. Occam’s razor is applicable.
(My secret fetish is plasma physics).
The Economist puts the cost of the fusion reactor at some $5 billion on construction, $5 billion on operating costs over 20 years and more than $1 billion on decommissioning.
The conclusion is that the benefits are only political.
http://www.economist.com/science/PrinterFriendly.cfm?Story_ID=4127211
The following information was provided by my daugher Caroline Marohasy:
http://www-fusion-magnetique.cea.fr/gb/fusion/surete01.htm#ch2
The above link provides information on fusion from a waste perspective, and I quote, “Fuels used in a fusion reactor are abundant, equally spread throughout the world and have a high energy density. Deuterium is extracted from seawater and the reserves are estimated at several million years. In a fusion reaction, the tritium will be manufactured in-situ from the lithium, which is very abundant in the earth’s crust and in the oceans. Consequently, none of the basic fuels, deuterium and lithium, nor the product of the reaction, helium (a neutral gas), is radioactive. If we exclude the initial start-up, which needs an initial load of tritium, a fusion reactor does not involve the transport of radioactive material.
At the end of a fusion reactor’s life, the materials surrounding the plasma, and constituting the structure of the reactor will be radioactive. As regards environmental impact, the choice of low activation material (i.e.with rapid decay time) for these structural elements minimises the quantities of radioactive waste. After a period of 100 years following the definitive shutdown of the reactor, most (even all) of the materials can be considered as waste with very low radioactivity (satisfying norms of declassification of nuclear waste defined by the AIEA and recommended by the European Commission) or recycled in the nuclear sector.”