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Physics/Nuclear Fusion Reactors


QUESTION: On December 12th of this year of 2015 while on the internet,I came across the best news of my life.That being the successful testing just two days earlier on December 10th, of a Nuclear Fusion Reactor.Yes the first ever successful test from a Nuclear Fusion Reactor. This as I understand it is a Reactor that was built for testing purposes only and will never be used to produce energy itself.It's over in Germany and is called The Stellarator. From reading the article about it I understand how it works by having a series of twisted magnets that are able to contain the plasma that is flowing inside and cannot be allowed to touch the inner walls of the reactor.Thus we have finally found the Holy Grail a container able to hold the extremely ultra high temperatures of a Nuclear Fusion Reaction..That being said and atoms being combined instead of destroyed to produce energy, I shall now finally get to my question for you to answer.#1-Will if Nuclear Fusion Reactors do become a reality, will they be able to supply the world with all of it's energy needs one day and will that lead to cheap if not free energy such as they have in the Star Trek shows? #2-Please answer this question also.If scientist have further successful test results on these Fusion Reactors is there people in politics especially those beholden to the fossil fuel sector, that will prevent these Reactors from ever seeing the light of day and ever being built? I should really, really hope not.#3-I'm sorry just one last question.These Fusion Reactors will be powerful but just how powerful.For instance could one Fusion Reactor by itself run the whole state of Florida? I thank you very ,very much.As this has been a subject that been with me since my early science grade school years.I care very much about this world and I truly want more than anything to see that Nuclear Fusion becomes a reality. Once again Thank you.

ANSWER: Correction: it sustained a plasma for the first time.  It did not achieve breakeven energy production, no fusion reactor to date has done so.  There are many such machines racing toward that target, but all of them have been plagued with cost overruns and many years of delay.  My personal bet on the matter is that very small fusion reactors will get there first, actually, they're the easiest to make progress on.  I know this news is somewhat disappointing, I've been waiting for 30+ years to hear that one of them actually worked (that's about when I first read about fusion reactors).

Your general idea of how it confines plasma is correct.  These devices have been around since the 1950's, but getting plasma hot enough to generate enough fusion so that more energy can be extracted than is pumped in has not yet happened.  Fusion reactions happen and are studied, but not enough of them.  It's also difficult to extract the energy, but I'm hopeful that past the first successful test of an above-breakeven device we will quickly advance to direct energy extraction (where charged reacting particles in the magnetic field emit microwaves that can be directly converted to power).

To your questions: 1) Potentially yes.  The fuels are abundant, and very high in energy density.  The waste products are both very small compared to fission reactors, and in general very short-lived (meaning we don't have to store them for thousands of years).  2) The fossil fuel sector won't immediately suffer, it will take a very long time to build such reactors and have them supply significant power...and they're very expensive to build and run.  The fossil fuel companies would be able to invest in the technology and potentially drastically reduce the cost of producing I expect the people in such companies with the money to invest and the expertise in the power industry actually have the most to gain (financially).  3)  The planned ones are about like typical power plants, there are no plans for mega-reactors.  They would require too much cooling water, unless direct electrical extraction can be achieved.  That's a whole next generation of untested technology.

So there's plenty to hope for...but it doesn't work yet.

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QUESTION: I have a small follow up question . First let me begin by saying I am extremely disappointed in finding out that we are further away from actually achieving a viable Nuclear Fusion energy source to supply our worlds needs,then what we are actually at.I know you had to bring me the bad news,and I'm not holding you accountable.But damn I was sort of hoping for a Star Trek kind of world,where free (or at least very cheap)energy would lead to a society that was able to promote itself as one that pursued scholarly endeavors.Okay now finally to my follow up question. From what I read about, once Nuclear Fusion does get going it should be pretty much self sustaining. Therefor they shouldn't cost that much to maintain and run them as what you have stated.Or did I somehow interpret the article I read about them.

A fusion reaction is a source of energy.  Barring direct electrical extraction, that means it's a source of heat, which is used to drive a large thermodynamic engine (turbine) to convert that energy into electricity.  Basically, like all power plants that we envision, it's part of a huge machine.  Machines require maintenance.  Huge machines require more expensive maintenance, and power plants are just about the biggest machines in existence.  Yes, confined plasmas can be self-heating once breakeven has been achieved, but the confinement will still require a lot of power (generated, of course, by the power plant).  They will still be vastly cheaper to operate, once built, than a power plant that requires large amounts of fuel, yes.  That's one of their main attractions.  So keep your fingers crossed that ITER or NIF get online fast!  Then we'll have a more realistic idea of what the side costs will be.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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