A contamination analysis of the primary coolant system with Monte Carlo simulations

Abstract In this paper, a contamination analysis for the primary systems of the nuclear power plant has been carried out in order to prepare decommissioning plans in the near future in Korea. The main radioactive isotopic sources of the activation products in the primary coolant system are estimated by setting up the simple balance equations. The inputs of isotopic activation analysis in the primary coolant system are derived mainly from a typical PWR in Korea. For the reliable neutron activation analysis, the neutron flux distribution is obtained from the 3-dimensional reactor modeling by using the Monte Carlo code. Among various corrosion products, Co-60 contributes significantly to the radioactive contamination in the primary coolant. The activity of Co-60 in the steam generator is estimated from the modeling and is validated with the measured data.