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Plutonium-238 (238 Pu or Pu-238) is a radioactive isotope of plutonium that has a half-life of 87.7 years. Plutonium-238 is a very powerful alpha emitter ; as alpha particles are easily blocked, this makes the plutonium-238 isotope suitable for usage in radioisotope thermoelectric generators (RTGs) and radioisotope heater units .
238 Pu has become the most widely used fuel for RTGs, in the form of plutonium(IV) oxide (PuO 2). [34] However, plutonium(IV) oxide containing a natural abundance of oxygen emits neutrons at the rate of roughly 2.3 × 10 3 n/sec/g of plutonium-238. This emission rate is relatively high compared to the neutron emission rate of plutonium-238 metal.
Plutonium is an element in which the 5f electronsare the transition border between delocalized and localized; it is therefore considered one of the most complex elements.[44] The anomalous behavior of plutonium is caused by its electronic structure. The energy difference between the 6d and 5f subshells is very low.
talk. edit. Plutonium (94 Pu) is an artificial element, except for trace quantities resulting from neutron capture by uranium, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized being plutonium-238 in 1940.
Reactor-grade plutonium. Reactor-grade plutonium (RGPu)[1][2] is the isotopic grade of plutonium that is found in spent nuclear fuel after the uranium-235 primary fuel that a nuclear power reactor uses has burnt up. The uranium-238 from which most of the plutonium isotopes derive by neutron capture is found along with the U-235 in the low ...
Diagram of a radioisotope heater unit. A radioisotope heater unit (RHU) is a small device that provides heat through radioactive decay. [1] They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium-238—although other radioactive isotopes could be used.
The RTG was the power source for the ALSEP. It utilized the heat from the radioactive decay of plutonium-238 and thermocouples to generate approximately 70 watts of power. The base of the RTG was the base of the second ALSEP subpackage. RTG Cask The RTG cask stored the plutonium-238 fuel element. It was located to left of the SEQ bay.
The advanced Stirling radioisotope generator (ASRG) is a radioisotope power system first developed at NASA's Glenn Research Center. It uses a Stirling power conversion technology to convert radioactive-decay heat into electricity for use on spacecraft. The energy conversion process used by an ASRG is significantly more efficient than previous ...