Optimization of the Tritium Production and Discharge in HPR1000

Tritium is one of the most important radioisotopes discharged into the environment in the reactor and contributes to 99% of the total radioactivity of all radionuclides in the liquid discharges during the normal operation of pressurized water reactors. The discharged tritium can be taken into the human body via drinking water. Therefore the minimization of production and discharge of tritium has been highly focused on in the industry and the public across the world. In the paper, all the sources of tritium generation in HPR1000 have been introduced. Activation of Boron-10 in the primary loops and Beryllium from secondary neutron sources have been recognized as the two main sources of tritium in the primary coolant in HPR1000. The annual tritium production and discharge in HPR1000 have been estimated to be about 4.2E+01 TBq/yr using CGN OPEX data with appropriate corrections to reflect tritium-related differences between HPR1000 and the CGN units. To minimize tritium discharges as far as possible, the feasibility of eliminating the secondary neutron source assemblies from the third cycle in the HPR1000 has been verified and the annual tritium can decrease by up to 48% correspondingly. The method used in the study has been certified by UK Generic Design Assessment and EUR compliance assessment. This approach can also be applied to the minimization of tritium discharges in operating PWR units and in the new PWR units.