Environmental contamination with tritium and radiocarbon

Besides the interaction of cosmic radiation with 14N nuclei in the Earth's atmosphere, tritium is produced in the operation of nuclear facilities, i.e., by reactions 3He(n,p)3H, 6Li(n,α)3H, 14N(n,t)12C, 2H(n,γ)3H and 10B(n,2α)3H. Carbon 14 is produced in the atmosphere by the reaction of cosmic radiation neutrons with 14N atoms. In the operation of nuclear power plants it also is produced by reaction 14N(n,p)14C. In order to ascertain the concentration of tritium in the atmosphere in the vicinity of nuclear power plants, condensation of atmospheric humidity by separation of HTO vapours in cold traps is used. 14C occurs in the form of CO2 and its concentration may be determined by the reaction of CO2 with barium hydroxide or with sodium hydroxide. The results of the measurement of 14C concentrations in the vicinity of the Bohunice A-1 nuclear power plant since 1968 are given in graphs. The tritium concentrations in water courses and in wells in the vicinity of the A-1 nuclear power plant have been observed since 1972 and the results are given in a table. The measurements show that the operation of the A-1 nuclear power plant has not resulted in any significant increase in concentrations of 14C or 3H in the ambient environment. (J.B.)