Public doses due to tritium emissions from Cernavoda NPP

Heavy water reactors have a large tritium load. In a CANDU reactor most of the tritium is formed in the thermal-neutron-capture reaction, 2H(n,γ)3H which occurs both in the moderator and heat transfer system. Very small amounts of tritiated heavy water may escape from moderator and heat-transport systems of CANDU reactors during maintenance and normal operation. Tritium emissions of Cernavoda NPP were continuously monitored. The tritium concentrations in environmental samples were monitored as part of routine program and public doses were calculated. This paper presents the supplementary tritium doses for a member of public, estimated using HTO concentrations in environmental samples and OBT doses estimated based on Candu Owners Group studies 'OBT/HTO Ratio in plants' and 'Contribution of Organically Bound Tritium to total Tritium Dose'. (authors)