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This is a list of the highest known prices paid for philatelic items, including stamps and covers. The current record price for a single stamp is US$ 9,480,000 paid for the British Guiana 1c magenta. [1][2] This list is ordered by consumer price index inflation-adjusted value (in bold) in millions of United States dollars in 2023. [note 1 ...
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 .
Sold in June 2014 at Sotheby's for $9.48 million. Philatelic investment is investment in collectible postage stamps for the purpose of realizing a profit. Philatelic investment was popular during the 1970s but then fell out of favour following a speculative bubble and prices of rare stamps took many years to recover.
The advent of the two-hundred dollar gold series was quickly joined by a platinum series. These high-quality collector coins solidified the RCM's entry into the luxury coin market. A four-coin set with face values of $30, $75, $150, and $300 respectively were complemented by the high-quality artwork that adorned these luxury items.
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 ...
The isotope produces 0.57 watts of thermal power per gram of 238 Pu. [5] Soviet missions have used other isotopes, such as the polonium-210 heat source used in the Lunokhod lunar rovers. [6] [7] With a half-life of 138.376 days, polonium-210 produces more thermal power per unit mass, but is suitable only for shorter duration missions.
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 ]
Hanford Site. Coordinates: 46°38′51″N 119°35′55″W. Nuclear reactors line the riverbank at the Hanford Site along the Columbia River in January 1960. The N Reactor is in the foreground, with the twin KE and KW Reactors in the immediate background. The historic B Reactor, the world's first plutonium production reactor, is visible in the ...