Research on KRT Monitoring Instrument Alarm Threshold in Main Control Room of Nuclear Power Plant

In this paper, the intake air gamma radioactive monitoring alarm threshold of nuclear plant main control room was studied for both under normal operation condition and accident conditions. According to two different layout schemes, gamma radiation dose rate of measuring point was calculated by the MCNP code under three typical accidents (including S3, DBA-LOCA and LOCA conditions). The results show that it is proper that to keep original value of the detector alarm threshold of improved main control room, it could provide effective radiation protection for indoor staff.