Nuclear Fusion is the next step

[Jack Still]

Whilst nuclear fission is an excellent power source for the current population of Earth, and even with new fast-breeder reactors, the fuel to power nuclear reactors will not last forever. Given that nuclear fuels are heavy elements and generally heavy elements tend to be rarer why not use light elements like hydrogen which are in abundance.

I am of course talking about Nuclear fusion, where rather than splitting heavy elements into lighter ones, we fuse light elements into heavier ones.
Considering that 75% of the universe is made up of Hydrogen I don't think fuel supplies will be a concern.

Therefore while I am an advocate of nuclear fission, I think nuclear fusion is a much more viable alternative in the long term. (I'm talking very long term, nuclear fission fuels will last longer with the newer reactors).

I expect many people on these forums support nuclear power of all types. Therefore people may be interested in this place:

http://www.fusion.org.uk/

I recently took a tour of this facility and we are on the brink of being able to harness fusion to its full potential. The next large fusion reactor (ITER) will be 10 times larger and should produce more energy than it took to start the reaction. (At the moment we use up the same amount of energy starting the reaction as we produce).

I hope that many more people become more aware of the potential of fusion and that it gets more funding from governments in the future.

Thanks,

Jack Still

[Lantzelot]

Hello Jack,

There are many of us hoping that nuclear fusion will deliver energy, practically "for ever". But we are not there yet, just as we do not have full scale Generation-IV reactors yet. The ITER project is very fascinating and will bring the research and development many steps ahead, but it is also important to be aware of that ITER will not even answer the question "how do we extract the energy in a practical way?" That will be the task of the follow-up project, called DEMO, so it seems that there will be many years before we have a full scale fusion reactor up and running. This does not mean that we are not interested in the subject, but we tend to focus more on the issues at hand with nuclear power of today and what we can expect from Generation-IV scenarios.

Anyhow, you and others are always welcome to post information of general interest related to nuclear fusion.

Here are a few alternative links related to the fusion projects in Culham and Cadarache:
JET: http://www.jet.efda.org/
ITER: http://www.iter.org/
And a nice video of an experiment at MAST (also in Culham): http://www.youtube.com/watch?v=m7nSmoYoPMc

[GCarty]

To get through the 21st century, we need to phase out as much fossil fuel usage as possible and replace it with nuclear fission. Fusion will probably dominate the 22nd century though

[Dag Lindgren]

The hope for fusion power is one reason to now continue building improved fission reactors. The addition of technology of nucleus management to Man´s toolbox meant that Mankind entered a new era – “the atomic age”. Sixty years ago the nucleus seemed to offer unlimited possibilities. Nuclear energy has not full-filled what then seemed reasonable realistic optimistic expectations, e.g. concerning economy, fuel cycle, safety and share of world energy; and has not developed into the unchallenged major power producer. However, nuclear energy has not got its development potential fully explored. The development and implementation require big machines, which take long time and huge resources to plan and build, thus development tends to be rather slow. The nuclear solution has got its development retarded as it is a symbol of destructive forces of Mankind. Hopefully this association will become weaker as decades pass and nuclear weapons receive less attention. Fission power has not been a failure, it has worked well for three decades and contributes today considerable to Swedish electricity production and – if undisturbed by political interference – will continue to do that in the foreseeable future. Fission power is under development and the “fourth generation reactor” seems able to offer better solutions to some of the problems, but it remains to be seen if that really means a big jump.
The most evident long-term development is controlled fusion. Fusion is a major energy source of the Universe almost since creation, thus in a way very “natural”. It took only seven years between the fission bomb and the fusion bomb, so it seemed reasonable half a century ago that practical energy production would have came nearer now, but it was realized that the difficulties were huge. Fusion power may have an unlimited potential, but the difficulties to get a practical working system is huge and it is not certain it ever will offer a superior solution.
The nuclear solution still offers hopes to be very superior to others sometime in the future. Abundant energy has probably unforeseen consequences (like faster pollution, exhaustion of other resources, still higher population number to please). Exploitation of Earth is fast and in the near past till the near future driven by fossil fuels. This has many risks and Mankind has difficulties to switch to long-term sustainability. The living standard is now rather good and improvements are probably not that much driven by the rate of technological progress, it seems more important to use the existing technology and resources wiser. Maybe it is a good thing we have to wait with Abundant Energy (which fusion may give us 2200) till we are more mature for that step.

[KitemanSA]

From all the data I have seen, it looks like these researchers think it will take about $50B and 50y to make fusion from a tokomak a reality, and even at that point, they are not sure it can be made cost effective.

For 1/20th that cost and 1/10th that time, Liquid Fluoride Thorium Recyclers (LFTRs) could be up and being produced on an assembly line which could pump out 100MWe of capacity per day. Seems our priorities are all messed up!

Oh, and by the way, it may be possible that Polywell fusion might also be as cheap as LFTRs, but they haven't been proven yet.

[Kismet80]

I dont agree that nuclear fusion is particularly necessary. The world is absolutely not running out of fission fuels, and will not in the lifetime of our civilization.
Fusion development has not been neglected by governments, dozens of countries have fusion reactors from Canada to South Korea, and of course there is the super-massive ITER fusion project. I'd say fusion is being pursued vigourously. I'm not sure what more we could really be doing, except probably in peripheral fields. Maybe if we can build better lasers it will help fusion ignition. Maybe if we can find better containment or a way to harvest the energy from a fusion reaction.

There is unbelievable amounts of fissile fuels out there. The only way you could draw the conclusion that it is in anyway limited is by imagining that we have a shortage of U-235. (Even that, is definitely open to debate, the last decades have been characterized by a glut of surplus uranium on the market making exploration and exploitation not commerically viable) Obviously, U-238 is massively abundant and its not believable we could exhaust all of that. Reactors do not need to have enriched uranium fuel, they can be run on natural uranium, thorium, or plutonium. We dont really have any problem with nuclear waste, nuclear waste is just tomorrows fuel.

Fusion is a fascinating technology, but I do not see the urgency of a fuel shortage as a relevant motivation. Nor do I see the danger in current fission technologies as being a strong motivation for nuclear fusion.
I'd say fast breeder reactors are the next step, thorium as fuel perhaps. Further reactors for reprocessing...

[Matte]

There is another very compelling reason for researching fusion, especially the polywell. The exploration of interstellar space will then become open to us and even to visit other starsystems within the confines of single human lifetimes (return trips even!!!). There will come a day when we really have to build the proverbial Arc and leave this solar system (yes it is a long way away), but if humans are to survive as a species in the universe we have to explore space around us and find habitable planets orbiting younger stars than our own.

Another thing, with the huge leaps in space propulsion technology a whole other avenue of projects opens up as being viable and even economic, terraforming Mars and Venus. These planets can be made habitable by depositing the vast amounts of water trapped in the Cupier belt. This can be achieved by fusion propelled drones shutteling water to and from the inner planets and the Cupier belt.

So even if fusion is not necessary as a means for energy production for civilisation here on earth, it is a must if we want to be able to survive as a species when the sun runs out of fuel...

[KitemanSA]

I dont agree that nuclear fusion is particularly necessary. The world is absolutely not running out of fission fuels, and will not in the lifetime of our civilization.

True. Accessible Thorium for LFTRs should suffice for about 500 million years. If we can't get something better in that time...