Isotopes of hydrogen used for deuterium and tritium. The IUPAC accepts the D and T symbols, but recommends instead using standard isotopic symbols (H and H) to avoid confusion in the alphabetic sorting of chemical formulas. The ordinary isotope of hydrogen, with no neutrons, is sometimes called "protium". (During the early study of radioactivity, some other heavy radioactive isotopes were given names, H (atomic mass u) is the most common hydrogen isotope with an abundance of more than 99.98%. Because the nucleus of this isotope consists of only a single proton, it is given the formal name "protium". The proton has never been
Radioactive contamination from the Rocky Flats Plant caused by normal operations rather than accidental releases. From September 1947 to April 1969 there were 5 or more accidental surface water releases of tritium. Tritium, a radioactive element which was found in scrap material from Rocky Flats, was therefore directed in to the Great Western Reservoir. This was uncovered in 1973 and following this, urine samples were taken from people living or working near Broomfield who could have drunk water from the reservoir. The findings of the samples showed that those who were exposed to contaminated water had tritium concentrations near seven times higher than normal (4,300 picocuries per