Not sure how it generates power? Pu238 is a very strong alpha emitter. Alpha particles (helium nuclei) are really big and charged, so they don't travel very fa

Not sure how it generates power? Pu238 is a very strong alpha emitter. Alpha particles (helium nuclei) are really big and charged, so they don't travel very far and deposit all their energy near where the decay occurs (as opposed to decay with e.g. neutrinos that essentially never interact and thus deposit no energy). The alpha decay carries a lot of energy so a chunk of Pu238 gets pretty hot. Couple it with a thermoelectric generator and you have an ideal power source for space applications. Also, alpha particles have almost no penetrative power in human tissue so they're harmless as long as the source isn't inside of you. Pu238 is almost exclusively an alpha emitter, so it's completely safe to handle for extended periods, at least radiologically. It puts off a ton of heat and is chemically really toxic though. I've dealt with it in the lab before, it's relatively harmless as far as nuclear sources go. It's not suited for weapons either, so it isn't directly a proliferation concern, though producing it is because it is related to weapons grade production. You don't see it used very often mostly because it can only be made in a specially configured reactor, so it's not exactly common.