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Chest nuclear reactor: how do pacemakers work with a perpetual battery?

Pacemakers are used to stimulateregular heartbeat, when the natural electrical pacing system in the body ceases to perform its function or does not work correctly. For many years, we have been looking for the best “batteries” for pacemakers. Among them were thermoelectric batteries containing from 2 to 4 curies of plutonium-238, a radioactive element with a half-life of 88 years. How did these perpetual batteries work? How dangerous is it for a person?

How plutonium pacemakers work

As follows from the term "thermoelectric",heat from decaying plutonium is used to generate electricity that stimulates the heart. In the early 2000s, there were between 50 and 100 people in the USA with atomic energy pacemakers. Each time one of these people died, the pacemaker was removed and sent to Los Alamos, where plutonium was subsequently recovered and recovered.

As seen in the photo of the pacemaker (alreadywithout plutonium) above, the device electronics is encased in epoxy. The solid titanium case is designed to withstand any possible damage events, including shots and cremation.

The dose of radiation on the surface of the pacemakeris about 5-15 mrem (microbar, “biological equivalent of X-ray”, unit of measurement) per hour from emitted gamma rays and neutrons. The estimated total body exposure is approximately 0.1 rem per year for the patient and approximately 7.5 mrem per year for his spouse. For comparison, 100 mrem is the background exposure that a person receives on average per year.

Often, plutonium pacemakers have experiencedtheir owners. In 1973, Dr. Victor Parsonnet, a staff member at Newark Medical Center Beth Israel, installed a Numec NU-5 pacemaker for a 20-year-old woman. At that time, the device cost the patient $ 23,000 in terms of a modern course. However, in the long term, the nuclear pacemaker was very economical - any other similar device for such a period would need to be changed four to five times.

According to Parsonnet, NU-5 was installed in 139 patients. Most of them are no longer alive.

Battery in a pacemaker like we alreadythey said that a radioisotope thermoelectric generator (RTG) is used, which uses thermal energy released during the natural decay of radioactive isotopes and converts it into electricity using a thermoelectric generator. Compared to nuclear fission reactions that occur at conventional nuclear power plants, RTGs are much more compact. They have low efficiency, as well as output power, but they do not require maintenance and have been operating for decades. Many satellites that we launched into the cold depths of space, like the same Voyagers, carried the RTG with plutonium-238 with them - this is the secret of their long-lasting work.

Why do not we use such eternal batterieseverywhere? The fact is that plutonium-238 has ended. Once it was produced as a side material in the production of nuclear weapons. However, those days are long gone, but they did not have time to start production of plutonium-238 directly.

Read more about plutonium-238 production in this article.

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