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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 .
Graphite flakes can cost around US$0.9/kg carbon. [20] Price of synthetic industrial diamond for grinding and polishing can range from 1200 to 13 300 USD/kg, while cost per weight of large synthetic diamonds for industrial applications can be on the order of million dollars per kilogram. [21] 7: N: Nitrogen: 0.0012506: 19 (5.263 × 10 17 kg) 0. ...
U-232 hazards, a result of its highly radioactive decay products such as thallium-208, are significant even at 5 parts per million. Implosion nuclear weapons require U-232 levels below 50 PPM (above which the U-233 is considered "low grade"; cf. "Standard weapon grade plutonium requires a Pu-240 content of no more than 6.5
For instance, 3.6 kg of plutonium-238 undergoes the same number of radioactive decays per second as 1 tonne of plutonium-239. Since the morbidity of the two isotopes in terms of absorbed radioactivity is almost exactly the same, [55] plutonium-238 is around 275 times more toxic by weight than plutonium-239.
Plutonium–gallium alloy (Pu–Ga) is an alloy of plutonium and gallium, used in nuclear weapon pits, the component of a nuclear weapon where the fission chain reaction is started. This alloy was developed during the Manhattan Project .
Trace amounts of plutonium-238, plutonium-239, plutonium-240, and plutonium-244 can be found in nature. Small traces of plutonium-239, a few parts per trillion, and its decay products are naturally found in some concentrated ores of uranium, [52] such as the natural nuclear fission reactor in Oklo, Gabon. [53]
The testing, completed by the Jefferson Parkway Public Highway Authority in preparation for road construction, observed one soil sample with a plutonium level of 264 picocuries per gram. For reference, the Rocky Flats remediation standard is 50 picocuries per gram. A second sample registered just 1.5 picocuries of plutonium per gram. [48]
The higher the burnup, the more plutonium is present in the spent fuel, but the available fissile plutonium is lower. Typically about one percent of the used fuel discharged from a reactor is plutonium, and some two thirds of this is fissile (c. 50% 239 Pu, 15% 241 Pu).