Nuclear-Powered Cardiac Pacemakers

Nuclear-Powered Cardiac Pacemakers
osrp.lanl.gov

WTF!?! We have plutonium powered pacemakers?

http://large.stanford.edu/courses/2015/ph241/degraw2/

Ah, okay we had.

> Despite the often longer life-expectancies, nuclear pacemakers quickly became a part of the past when lithium batteries were developed. Not only did the technology improve, allowing for lighter, smaller, and programmable pacemakers, but doctors began to realize that this excessive longevity of nuclear pacemakers was excessive. Lithium pacemakers often last 10-15 years allowing for doctors to check in on their patients and replace either the batteries or the pacemakers themselves with new and improved technology as it is develops in those 10-15 year spans.

These batteries have very poor power density and are very inefficient. The advantages of nuclear-powered batteries are:

- They generate power over a long time, decades,

- They generate some heat.

They don’t generate much power. If you have a building, you would definitely think of a nuclear RTG as a “very shitty battery”, and that’s even if you don’t care at all about radioactivity.

Thinking of these as a “battery” is also a bit misleading, IMO. These are really just small power plants, which generate heat and turn the heat into electricity. The heat is powered by radioactive decay of Pu-238, and then turned into electricity with the extremely inefficient Seebeck effect. If you had a source of heat you wanted to turn into electricity, it’s much more efficient to use that heat to turn a turbine which is connected to a generator. And if you want an efficient, cost-effictive turbine, you make it big. At that point, you have a power plant.