- #36
Andre
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- 74
Coal fired plants also emit some radioactive carbon.
Radioactive carbon is generated in the atmosphere under cosmic bombardment:
14N + n => 14C + p The amount of radio carbon in the atmosphere is proportional with the cosmic activity. The radioactive carbon enters the carbon cycle by photosynthesis. Hence green plants are the most radioactive. 14C has a half value time of about 5700 years so the amount in the organisms and fossil remains decays with time. The carbon dating method is based on this phenomenon. Consequently very old fossils like coal get depleted of 14C in time and coal is no longer radio-active in a measuable amount due to 14C.