Take the 2-minute tour ×
Skeptics Stack Exchange is a question and answer site for scientific skepticism. It's 100% free, no registration required.

With my limited knowledge of the process of nuclear fusion energy, this seems like one of the most promising methods for producing huge amounts of energy, with relatively very low risk, once researchers manage to control the process.

The claim goes that the nuclear waste of nuclear fusion is negligible and that the process of generating nuclear fusion energy is easily containable, contrary to nuclear fission energy.

However, are there any significant risks involved I may not be aware of yet?


locked by Sklivvz Apr 6 at 22:12

This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: help center.

Hard to say, while it probably won't produce a lot of radioactive leftovers, there is no working fusion energy system, how do you figure out what the risks really are? –  Zachary K Mar 29 '11 at 7:26

2 Answers 2

up vote 28 down vote accepted

All proposed methods of power generation using nuclear fusion will be safer than current methods using nuclear fission (assuming any of the proposed methods actually work).

Note: Fusion reactors will not use the H1 + H1 reaction that powers the Sun (see: proton–proton chain reaction)*. The current designs combine (fuse) some combination of isotopes of hydrogen: deuterium, or tritium. Safety issues are largely dependent how those elements are combined (see: fusion fuel cycle).

Some of the basic safety issues...

Possibily of "meltdown":

Continuous operation of the plant is maintained by continual refuelling with the fuel mixture (deuterium and tritium), so the fuel inventory in the plasma chamber at any time is sufficient only for about one minute of operation. --source

Production of radioactive waste:

Nearly all materials become activated to some degree by energetic neutron bombardment. Neutron reactions in DT fusion reactors will inevitably create radioisotopes. The principal radioactive materials present in a DT fusion reactor will therefore be tritium and neutron activated structural materials surrounding the reaction volume. --source

Release of tritium: (as noted this would not be a concern in a deuterium-deuterium process)

There are also other concerns, principally regarding the possible release of tritium into the environment. It is radioactive and very difficult to contain since it can penetrate concrete, rubber and some grades of steel...snip...Each fusion reactor could release significant quantities of tritium during operation through routine leaks, assuming the best containment systems. An accident could release even more. This is one reason why long-term hopes are for the deuterium-deuterium fusion process, dispensing with tritium. --source

More sources of information:

The Wikipedia entry Fusion Power also is a reasonable source for the basics and further research.

*At the temperatures and densities in stellar cores the rates of fusion reactions are notoriously slow. For example, at solar core temperature (T ≈ 15 MK) and density (160 g/cm³), the energy release rate is only 276 μW/cm³—about a quarter of the volumetric rate at which a resting human body generates heat. (see: Astrophysical reaction chains)

+1, great answer. You may want to change source though. The World Nuclear Association is a pro-nuclear organization. Their article is well-referenced, though, so all you need is go to the primary source instead. –  Borror0 Mar 29 '11 at 7:53
@Borror0 Good point. Done. –  Rusty Mar 29 '11 at 23:07
@Borror nothing wrong with using a pro-nuclear group as a source if their information is correct, which it is. It's not as if he was using Greenpeace to point out based on solely emotional statements that "nuclear power is evil" :) –  jwenting Apr 27 '11 at 11:11
Any difference between magnetic or laser fusion, as to the risks? I've read claims that laser fusion could be used to make a pure fusion bomb (i.e. without a fission ignition); I wonder if that would have any implications for the risks. –  gerrit Oct 8 '13 at 23:40

Actually the first "real" Nuclear Fusion reactor is being constructed as the ITER project. Although they started digging in France, they are many problems yet to overcome. I put real into quotes because the goal of a reactor is to produce more energy then what is used to start the reaction, and this is one of the things that nobody has been able to achieve yet with fusion, as mentioned here.

Sorry for this introduction but it felt necessary. Now, for the dangers, a list is compiled here and the process seems really safe since in case of a problem, everything stop in a few seconds.

Of course, they are, as mentioned, many obstacles yet to overcome, and if the theory makes it safe, the implementation will create other variables.

Therefore, since we don't have a working prototype yet, we don't really know. Maybe on physics stackexchange you could have a more thorough answers.


I was to lazy to check, but @dmckee posted in the comments this link to physics.SE where they have this discussion! They say basically the same thing ;).

We had a short go at exactly this topic on physics.SE the other day. –  dmckee Mar 28 '11 at 3:28
@dmckee thanks for the link! Nice discussion, I should have checked. –  Zenon Mar 28 '11 at 3:38
-1 the part of your answer which is on-topic can be reduced to a sentence and a link. Please give us a run down of the dangers, for example. The rest of the answer, while interesting, is not what the OP asked for. –  Sklivvz Mar 29 '11 at 6:58
@skivvz I do agree, I upvoted Rusty answer instead ;) –  Zenon Mar 31 '11 at 14:41
"in case of a problem, everything stop in a few seconds" - well, they said this about nuclear fission too... –  Steed Feb 25 '13 at 15:47

Not the answer you're looking for? Browse other questions tagged or ask your own question.