Fusion FAQ

1) Will fusion ever work?

Fusion already works. Scientists have been performing magnetically-confined fusion in for decades. What has not yet been achieved is the creation of a fusion reactor that produces more power than it needs as input. The ITER research reactor is being constructed to do just that: produce 10 times more power than it takes to run. ITER is a cooperative effort involving the European Union, India, Japan, the People’s Republic of China, Russia, South Korea and the United States, currently in progress. The development of ITER draws from and is complimentary to work currently being done at U.S. research reactors, including Alcator C-MOD, DIII-D, NSTX-U and at the many important smaller scale facilities. 

 2) How fast has progress been in fusion?

Progress in fusion research has been very fast. For a comparison, think how fast progress in computational power has been.  Every few years your PC becomes obsolete because newer, faster models are introduced.  Progress in fusion, measured by a characteristic calculation called the Triple Product, has been just as fast. Both fusion’s Triple Product and the number of transistors in computer chips have doubled less than once every two years on average (Moore’s law). 

3) What’s the difference between fission and fusion?

Fission uses big atoms, like uranium, and breaks them down, which releases energy.  Fusion uses small atoms, like hydrogen, and combines them, which also releases energy.  They are both nuclear processes, that is, they change the nucleaus of the atom as opposed to chemical processes which change only the sharing of electrons between atoms.  Nuclear processes are much more energetic than chemical processes – thousands of times more energy is released per reaction.  We have prepared a quick Introduction to Fusion.

4) If fusion is nuclear, does it produce radioactive waste like fission does?

Almost none. Nuclear fission power, while a reliable energy source, has the disadvantage of generating long-lived byproducts which remain radioactive for millions of years.  Fusion reactors will use a type of hydrogen called tritium. Tritium is radioactive but its half life is very short – less than 13 years.  Precautions must be taken when dealing with tritium and the waste must be contained for a few decades, but there are no long lived radioactive byproducts of fusion reactions. For more information, see the Wikipedia article on Waste Management for fusion reactors.

5) Can fusion cause a nuclear “meltdown”?

No. Fusion cannot cause runaway reactions like fission can. If there is a loss of control in a fusion reactor, the reaction will be starved of energy and will instantly shut down, by itself. Fusion reactors are passively stable, meaning that they require no action from operators for a safe shutdown. For more information, see the Wikipedia article on  Accident Potential of fusion reactors.

6) Could you use fusion reactor research to make hydrogen bombs?

No. Although hydrogen bombs do use fusion reactions, to detonate they require an additional fission bomb. Magnetically-confined fusion cannot itself produce the amount of instantaneous power required for a weapon.  Magnetic confinement fusion research was even shared between the US and the USSR during the height of the Cold War.

7) What are fusion’s effects on the environment?

Fusion is among the most environmentally friendly sources of energy under development. Fusion produces no greenhouse gases and is a very low-pollution energy source. Its two sources of fuel, hydrogen and lithium, have a nearly inexhaustible supply. 

8) Why focus on fusion?

Fusion reactors would be a source of high-output, reliable, clean energy produced around the clock. Solar, wind, and tidal technologies have shown great advances in the last decade and are already in use as supplementary energy sources.  But each has disadvantages. The sun isn’t always shining, the wind isn’t always blowing, and tidal sources depend on the vagaries of the sea. Each would also require vast amounts of space to become a major source of electricity. The global population is expected to rise to over 10 billion by 2050 and to demand ever more energy. It is unikely that any of these sources will be a silver bullet. Along with fission power, solar panels, wind turbines, and other areas of research, fusion research is a critical part of the solution to our environmental crisis.

9) I want to get involved in fusion research? How do I do that?

If you are a high school or undergraduate, the best starting point is to take math, physics, engineering classes! After that, research oppurtunities in your institution, and in other institutions such as NUF, help you get into the field and are extremely neat. If you are close to graduating or have graduated from undergraduate school, you should apply to a Ph.D program in physics, nuclear engineering, electrical engineering, mechanical engineering etc. You can find many of these programs through a simple google search! Good grades, some work experience in the field, good physics GRE scores are helpful in getting accepted!

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