Environmental impact of nuclear power 20 other US nuclear plants in recent years, has kindled doubts about the reliability, durability, and maintenance of aging nuclear installations in the United States. Tritium is a radioactive isotope of hydrogen that emits a low-energy beta particle and is usually measured in becquerels (i.e. atoms decaying per second) per liter (Bq/L). Tritium can be contained in water released from a nuclear plant. The primary concern for tritium release is the presence in drinking water, in addition to biological magnification leading to tritium in crops and animals consumed for food. Tritium, the mass 3 isotope of hydrogen is deliberately created
Tritium in small quantities by some nuclear power plants. In January 2014 it was made public that a total of 875 TBq (2.45 g) of tritium are on the site of Fukushima Daiichi, and the amount of tritium contained in the contaminated water is increasing by approximately 230 TBq (0.64 g) per year. According to a report by Tepco ""Tritium could be separated theoretically, but there is no practical separation technology on an industrial scale"." Tritium's decay product helium-3 has a very large cross section for reacting with thermal neutrons, expelling a proton, hence it is rapidly converted back to tritium