ATOMIC REACTOR STATE MONITORING DEVICE AND MONITORING METHOD THEREOF

摘要

A reactor state monitoring apparatus 1 includes: a first gamma ray-dose measurement device 17, 23 that detects and measures a radiation dose in an atmosphere caused by radioactive substances which are on a side of a containment vessel 10 with respect to a biological shielding wall 11 surrounding a pressure vessel 2 and which are outside the pressure vessel 2; a second gamma ray-dose measurement device 15, 21 that detects and measures a radiation dose on the pressure vessel side with respect to the biological shielding wall 11; a fuel radiation measuring device 16, 21 that detects and measures a radiation dose of a fuel 3 contained in the pressure vessel; and a water amount evaluation device 24 that calculates a difference between the radiation dose measured by the fuel radiation measuring device and the radiation dose measured by the first gamma ray-dose measurement device as a corrected fuel radiation dose, and acquires a water level of a cooling water 4 as a water level evaluation value, based on the radiation dose measured by the second gamma ray-dose measurement device with use of the corrected fuel radiation dose.