Why is nuclear fusion a potentially safer energy source?

Answer 1

Fusion reactors are very much safer because-- 1) They can't "run away" 2) They leave few radioactive products when worn out. 3) They have no radioactive spent fuel. 4) They don't become dangerous if anything fails, they just stop.

Answer 2

The main product of fusion is Helium gas, which is not radioactive. The only radioactive waste should be limited to small parts of the reactor around the reaction chamber itself subject to neutron radiation that become radioactive due to neutron activation.

Answer 3

Nuclear fusion has pros and cons when compared to nuclear fission.

Pros -

Yields much more energy with less or no waste.

2 Hydrogen -> deuterium, yields only a little energy, but neither the fuel, not the product are radioactive.

more common is deuterium + tritium -> Helium + beta particle (of 5.7 keV, compared to the 4.3 MeV of alpha decay of U235) + 18.6 keV of energy for us. This may not seem like a lot of energy compared to fission reactions, but you must remember that these atoms are 1/100 the size, and thousands of times more compressed, yielding more energy per gram.

The beta particle that is released has very little penetration power (less then 1 inch of aluminum)

There is plenty of fuel, since we can get hydrogen from water, sugars, oils, natural gas, or anything. While fission material has to be dug up from within the earth.

Cons-

The reaction is much more challenging to start and control.

The nuclear reaction can runaway much faster, leaving less time to try to fix any issues or evacuate the area.

We have much less experience of doing Fusion and so that naturally means that there is going to be greater chance of mistakes.

Answer 4

Nuclear fusion is potentially a safer energy source than nuclear fission because it does not have any mixed fission byproducts, meaning that it does not leave behind residual radioactive material, beyond very short lived isotopes, nor does it leave behind decay heat.

However, we have yet to solve the seemingly intractable problem of maintaining the extraordinarily high temperatures and pressures required to sustain a controlled fusion reaction for more than a brief instant of time, nor have we solved the break-even problem, where the production of energy overcomes the energy input, which happens to be substantial due to the electromagnetic force that resists bringing nuclei together sufficiently to allow the stronger nuclear force to overcome it.

Answer 5

That would depend on many design parameters of the two reactors, as you don't identify any of the differences I cannot even consider answering your question.