Continuous measurement of iodine concentration in the primary coolant of a nuclear power plant

Kansai Electric Power Company, Ltd. together with four other utilities in Japan (Kyushu EPCO, Shikoku EPCO, Hokkaido EPCO, JAPCO) and Nuclear Electric Ltd. have developed a reliable on-line automated Iodine Concentration Monitoring System (IMS) for use at nuclear power plants. This IMS uses recent technological advances to enable the detection of even very low iodine concentrations in the reactor coolant water. A patent has recently been issued to NEL for this system design. The EGS-4 Monte Carlo simulation code was used to optimize the design of this IMS. This paper describes how the EGS-4 code was used as a design tool for the IMS and its various components.