Regulations be damned.

I guess when it comes to plutonium the US Nuclear Regulatory Commission doesn't want to take any chances – it's still frickin' plutonium after all. But yeah, having a pacemaker that'll essentially work the rest of the patient's life sounds pretty damn impressive, although I really don't know what the state of the art is.

But if we do want to sew radionuclides into people (because why not), maybe the same could be done with one that's a bit less spicy? I'd imagine that with modern technology you could get away with using something that wouldn't give you the same amount of power, but that also wouldn't be… well, plutonium.

They are, in the form of “diamond batteries”,

Huh, that's interesting. I found a wiki article that describes a diamond battery that generates current from beta particles emitted by carbon-14, but that one's only good for microwatts. I also found some pages that referred to diamond batteries that use nuclear waste, like this one, which might be what you were thinking of? No idea what the wattage of those would be, but I'd guess more than ^14^C

to put that into some interesting context that's about what your cell phone uses if you go through the battery over 24hrs. With a battery or big capacitor to act as an accumulator you could in theory have a smart phone that never needs charging, or rarely when you use it a lot in one night.

They didn't have boxes of scraps laying around... otherwise it absolutely would have happened.

A-ha, fellow interrobang enjoyer!

But yeah, how frickin' cool would it be to have an implant powered by an RTG‽ Honestly the most cyberpunk thing I've heard in a while

The Radium girls were from the 1920s or even before that. While they didn't know about the dangers that the Radium paint posed to them, their employers certainly did. Not only did those companies hide the truth from the women, they actively sabotaged any efforts to identify the problem and hold them responsible. These weasels went so far as to secretly pay the doctors around to falsely diagnose the women with syphilis instead of radiation poisoning - in an attempt to destroy their reputation and discredit them. The reckless use of radioactive substances back then wasn't entirely unintentional or based on innocent motives.

The action those women took was a revolution in workers' rights. But the moral of the story is, if a company can make money by subjecting you to hidden, but mortal dangers, they will - no matter how fatal that danger is. Then they will use a portion of that money to destroy your image and pin the blame on you. This tendency is even stronger today than it was back then. It was radiation back then - today there are a dozen other problems - lead, microplastics, PFAS and God knows what else.