Inhaltsverzeichnis
Wie gewinnt man reines Helium?
Helium entsteht daraus, wenn das Alphateilchen anderen Atomen zwei Elektronen entreißt. Das so entstandene Helium sammelt sich in natürlichen Erdgas-Vorkommen in Konzentrationen bis zu sieben Volumenprozent. Daher kann Helium durch Fraktionierte Destillation aus Erdgas gewonnen werden.
Ist Helium endlich?
Der irdische Vorrat an Helium ist endlich – und er wird immer knapper. Die Erdschwerkraft reicht nicht aus, um das Helium in der Atmosphäre zurückzuhalten. Alle noch existierenden Helium-Vorräte der Erde liegen daher im Untergrund – meist gekoppelt an Erdgas-Vorkommen. Doch diese Vorräte sind endlich.
What is helium and where does it come from?
Helium is being produced constantly as alpha particles in nuclear decay throughout the mass of the earth. The principle sources are naturally occurring uranium and thorium and their decay products. This helium then transits through the earth and may collect in natural gas deposits. It then passes through the atmosphere and into space.
How many helium atoms are emitted in uranium decay?
In the uranium decay series 8 α-particles are emitted in the decay from 238 U to 206 Pb. Thus for every 8 helium atoms found in a uranium mineral, one atom of 238 U must have decayed to 206 Pb.
What kind of uranium is used in nuclear power plants?
Commercial nuclear power plants use fuel that is typically enriched to around 3\% uranium-235. The CANDU and Magnox designs are the only commercial reactors capable of using unenriched uranium fuel. Fuel used for United States Navy reactors is typically highly enriched in uranium-235 (the exact values are classified).
What is the source and depletion of helium deposits?
It is somewhat misleading to refer to the depletion of „helium deposits“. Helium is being produced constantly as alpha particles in nuclear decay throughout the mass of the earth. The principle sources are naturally occurring uranium and thorium and their decay products.