Design of the Process and Effluent Radiation Monitoring System of HTR-PM

Abstract

The process and effluent radiation monitoring system can provide information about kinds of the radionuclide and activity concentrations, which is indispensable, important, and peculiar for a nuclear power station compared to a regular thermal power station. On the basis of knowledge about pressurized water reactors (PWRs) and high temperature gas-cooled reactors (HTGRs), the process and effluent radiation monitoring system of HTR-PM has been designed. It mainly contains several monitoring channels for concerned process systems, certain important areas, and gaseous and liquid effluents. For the coolant is helium and spherical fuel elements containing tristructural isotropic (TRISO) coated particles are adopted in HTR-PM, the source terms are different from those of PWRs. Not only fission or activation products in the gaseous or liquid form are monitored, but also the radioactive dust in the primary loop is sampled for analysis. The tritium (H-3) and carbon-14 (C-14) are taken a key consideration, which will be sampled in the primary loop, in certain important areas, in the secondary loop, and in the gaseous effluent in the stack. Design features of the process and effluent radiation monitoring system of HTR-PM are introduced and discussed compared to those of PWRs.