Abstract: A reactor state monitoring apparatus including: a first gamma ray-dose measurement device that detects and measures an atmospheric radiation dose caused by radioactive substances on a containment vessel side respective to a biological shielding wall surrounding a pressure vessel and outside the pressure vessel; a second gamma ray-dose measurement device that detects and measures a radiation dose on the pressure vessel side respective to the biological shielding wall; a fuel radiation measuring device that detects and measures a radiation dose of fuel in the pressure vessel; and a water amount evaluation device that calculates a difference between radiation doses measured by the fuel radiation measuring device and the first gamma ray-dose measurement device as a corrected fuel radiation dose, and acquires a cooling water level as a water level evaluation value, based on the radiation dose measured by the second gamma ray-dose measurement device and the corrected fuel radiation dose.

Abstract: Provided is a liquid level measuring technique capable of measuring a liquid level with high accuracy even if a liquid stored in a container is boiling.

Abstract: Provided is a apparatus for sensing a liquid level reliably based solely on an analog process even if a liquid held in a container boils, causing the liquid level to fall.

Abstract: Provided is a apparatus for sensing a liquid level reliably based solely on an analog process even if a liquid held in a container boils, causing the liquid level to fall.

Abstract: A reactor state monitoring apparatus including: a first gamma ray-dose measurement device that detects and measures an atmospheric radiation dose caused by radioactive substances on a containment vessel side respective to a biological shielding wall surrounding a pressure vessel and outside the pressure vessel; a second gamma ray-dose measurement device that detects and measures a radiation dose on the pressure vessel side respective to the biological shielding wall; a fuel radiation measuring device that detects and measures a radiation dose of fuel in the pressure vessel; and a water amount evaluation device that calculates a difference between radiation doses measured by the fuel radiation measuring device and the first gamma ray-dose measurement device as a corrected fuel radiation dose, and acquires a cooling water level as a water level evaluation value, based on the radiation dose measured by the second gamma ray-dose measurement device and the corrected fuel radiation dose.

Abstract: Provided is a liquid level measuring technique capable of measuring a liquid level with high accuracy even if a liquid stored in a container is boiling.

Abstract: The water-level and temperature measurement apparatus 10 includes monitoring devices 121, - - - , 12n that receives n water-level information and n temperature information, measures n water-levels and n temperatures, and determines whether a water-level detection function and a temperature detection function in each channel are lost or not based on electrical physical quantities, by using water-level and temperature detection devices 111, 112, 113, 114 which includes a detection unit 20 to detect water-level information and temperature information from thermocouple and heater wire, and a calculation processing device 13 that obtains at least one water-level measurement result and at least one temperature measurement result by using n water-level measurement results, n temperature measurement results, water-level detection function loss determination result in each channel, and temperature detection function loss determination result in each channel.