> Piece of a fission reactor became radioactive due to neutron bombardment. > Lost track of this radioactive piece in the pool, found it by accident, zap! > N

> Piece of a fission reactor became radioactive due to neutron bombardment. > Lost track of this radioactive piece in the pool, found it by accident, zap! > Neutrons make hardware radioactive. > Many on Hacker News fantasize about fusion (not fission) reactors. These fusion (not fission) reactors will be an intense source of fast neutrons. All the hardware in a fusion (not fission) reactor will become radioactive. Not to mention the gamma rays. > If you have to deal with radioactive materials, why not just use fission? After 70 years of working with fission reactors, we know how to build and operate them at 95%+ efficiency. Fission can provide all the power we will need in our lifetimes. What do you mean by 95% efficiency? Fission reactors are heat engines, their efficiency is much lower typical reactors are 35% while modern designs can reach up to 45%. That's the thermal efficiency, if we consider the energy stored inside the fission material it's much lower still.