Progress on the First Fusion Power plant

Delta Prime

Joined Nov 15, 2019
Kill all humans.
The sun is a natural fusion reactor which makes up for its measly 15 million degrees with the intense pressure created by its core's gravity. Currently, here on Earth the amount of energy you'd need to put in to produce that kind of heat or pressure is much, much higher than what you get out in usable energy. It's a pig in the poke. But hey who doesn't like bacon


Joined Jun 5, 2013
Wow, is that a blast from the past? My professors were just as excited about the tokamak reactors with superconducting magnets when I was studying physics at the University of Maryland, wait for it, 50 years ago.

Call me cynical, but it looks to me like not much has changed.



Joined Mar 24, 2008
We are due for new developments. Superconductors haven't sat still either. We are creeping toward a room temperature superconductor, that could happen anytime. If you don't count ridiculous conditions like extreme pressures, we are there already.


Joined Aug 27, 2009
We are due for new developments. Superconductors haven't sat still either. We are creeping toward a room temperature superconductor, that could happen anytime. If you don't count ridiculous conditions like extreme pressures, we are there already.
The cryogenic superconductor energy requirements for a fusion plant are not show stoppers using current technology but room temperature superconductors would be a huge improvement on the operational efficiency.
The ITER tokamak is a machine using superconducting magnets. The windings of these magnets will be subjected to high heat loads resulting from a combination of nuclear energy absorption and AC-losses. It is estimated that about 100 kW at 4.5 K are needed. The total cooling mass flow rate will be around 10 – 15 kg/s. In addition to the large cryogenic power required for the superconducting magnets cryogenic power is also needed for refrigerated radiation shield, various cryopumps, fuel processing and test beds. A general description of the overall layout and the envisaged refrigerator cycle, necessary cold pumps and ancillary equipment is given. The basic cryogenic layout for the ITER tokakmak design, as developed during the conceptual design phase and a short overview about existing tokamak designs using superconducting magnets is given.
The 4.5 K is a typical low temp superconductor. That 100kW will cost about ~70 times that in electrical energy input.

According to equation (1), to produce 1 W cooling power at 4.5K and 4.2K, a mechanical work of 65.67 W and 70.43 W is needed respectively

Delta Prime

Joined Nov 15, 2019
We are creeping toward a room temperature superconductor, that could happen anytime. If you don't count ridiculous conditions like extreme pressures, we are there already.
That's where the term cold fusion, the hope that fusion reactions can occur at relatively low temperatures, comes in. Once a promising theoretical goal, the field was largely written off as pseudoscience the late 1980s, when electrochemists Stanley Pons and Martin Fleischmann reported that their room-temperature electrolysis experiment had produced so much excess heat—as well as nuclear by-products like tritium—that only a nuclear reaction could be blamed. The attention led to a massive wave of cold-fusion experimenting, but no one was able to replicate their heat anomaly

Deleted member 115935

Joined Dec 31, 1969
I'm wondering
what will arrive first, practical fusion, or wold wide renewables ?

I'm old, and one of my first professors had worked on a fusion reactor project before I started.
they retired in the 80's,

Don't get me wrong,
Fusion has ever since I have bee aware, the ultimate goal, so I am biased to thinking its a world saver,
but, one does have to wonder..

Good luck to the teams researching this,
I'd imagine it will be a great bonus to space ships. once they can lift the weight.
infinite power to accelerate.


Joined Jan 6, 2004
It's still a ways off but very interesting once we get this worked out...
From the very start of the article offered by the OP:

The world's first nuclear fusion plant has now reached 50 percent completion, the project's director-general announced Dec. 6.

When it is operational, the experimental fusion plant, called the International Thermonuclear Experimental Reactor (ITER), will circulate plasma in its core that is 10 times hotter than the sun, surrounded by magnets as cold as interstellar space.

Its goal? To fuse hydrogen atoms and generate 10 times more power than goes into it by the 2030s.

Ultimately, ITER is meant to prove that fusion power can be generated on a commercial scale and is sustainable, abundant, safe. and clean.
Could anyone explain "more power than goes into it"?


Joined Apr 3, 2014
Could anyone explain "more power than goes into it"?
Agustín, you need to think like a physicist! Every physicist I've ever met thinks first about energy. Need to boil water, they'll calculate the energy needed to do it. Need to lift a piano to the third floor, again they'll answer how much energy it will take.

As for a fusion reactor, we know we can create the conditions to cause fusion. It takes a lot of energy put into the system to do that and for our troubles fusion may occur, but we've put more energy into the system than we've got back out. Energy in is used to chill the magnets, to heat the hydrogen plasma, and whatever other processes need to occur to start the fusion. If it takes more energy to start and maintain the fusion reaction than we get out then it's of no use as an energy source.

The end result of all of this effort has primarily been to assemble a practical fusion energy source. The idea is to replace our fission reactors currently in use. With luck it would reduce or eliminate waste material generation and provide nearly limitless clean energy generation.

Deleted member 115935

Joined Dec 31, 1969
re more power than goes into it,
like a nuclear power station, fusion stations need power to generate
in the case of fusion stations, its going to be mainly the plasma that has to be contained. and the initial heat / pressure needed to start the reaction that takes the power.

Currently , all fusion reactors, use more power to get the thing to "fire" than is recovered in the very small period the recation lasts


Joined Sep 24, 2011
Could anyone explain "more power than goes into it"?
The short answer is that the hydrogen to helium fusion reaction releases more energy and heat than it consumes.

Where does the excess energy come from? At the nuclear scale, the two dominant forces are the strong interaction (which wants to bind protons) and the electromagnetic interaction (which wants to separate protons). The strong interaction is ridiculously strong (hence its name), far stronger than the Coulomb force of the EM interaction. The catch is that the strong interaction has a ridiculously short range. At all but the tiniest of distances, the Coulomb repulsion is more powerful than the strong attraction. But if you can get two protons close enough together, the strong interaction will dominate and the two protons will fuse. Once fused, the new nucleon will be in a lower energy state than the old pair (since they will be "going with" the strong force rather than against it), and that difference in energy is released to the environment as heat.

How do you get protons close enough to each other to favor fusion? The easiest way is to heat them up to a sufficiently high temperature that they're all but smashing into each other. Hence, the "thermo" in thermonuclear fusion.

But as the number of nucleons in an atom increases, the distance between each proton necessarily grows. For atomic masses greater than iron, the nuclear distances become great enough to allow the Coulomb repulsion to dominate the strong attraction, and so fusion can no longer be an exothermic/exergonic reaction. For atoms larger than iron, fission is the energetically-favorable reaction -- and the bigger the atom, the more favorable.