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How do plutonium-powered pacemakers work?

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Re: How do plutonium-powered pacemakers work?

#5
post #4

Dumb question, but would it be possible to have a nuclear-powered object in your body producing energy for your body to use?

Keeping nuclear material (safely) in your body is the easy part, the hard part is converting that energy into something your body can use. The issue is, our (badly designed) meat-hardware runs on glucose instead of heat or electricity, and there's no easy (or any way that I know of really, but then I'm not a scientist) to convert heat/electricity into glucose.

Re: How do plutonium-powered pacemakers work?

#6

How long to these pacemakers last? Have people had to get the plutonium "batteries" replaced?

The half-life of Pu-238 (the isotope used in these) is 87.7 years [1]. So they pretty much last a lifetime. For the same reason, Voyager 1 is still kicking even though it's out of the solar system [2].

[1] https://en.wikipedia.org/wiki/Plutonium-238

[2] https://en.wikipedia.org/wiki/Voyager_1

Re: How do plutonium-powered pacemakers work?

#8
FTA:

> I wondered if there wasn't also worry about plutonium being recovered for weapons use, but the risk seems much smaller

The answer here is a simple "nope." Plutonium in radioisotopic thermal generators is always Plutonium-238 with a 87.7 year half-life. You can't make bombs out of it. The fissile isotopes of Plutonium are 239 (24,000 year half-life) and 241 (14 year half-life, but a beta emitter instead of alpha). The fission cross section (probability) of Pu-238 is >100 less than Pu-239 for a "normal-speed" neutron and also a lot less at fission-spectrum energies.

Re: How do plutonium-powered pacemakers work?

#10

How long to these pacemakers last? Have people had to get the plutonium "batteries" replaced?

The half-life of Pu-238 (the isotope used in these) is 87.7 years [1]. So they pretty much last a lifetime. For the same reason, Voyager 1 is still kicking even though it's out of the solar system [2]. [1] https://en.wikipedia.org/wiki/Plutonium-238 [2] https://en.wikipedia.org/wiki/Voyager_1

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