Patent Number: 6,310,929

Title: In-core fixed nuclear instrumentation system and power distribution monitoring system

Abstract: In an in-core fixed nuclear instrumentation system for a reactor, each of a plurality of in-core nuclear instrumentation assemblies has a nuclear instrumentation tube. LPRM detectors are housed in the nuclear instrumentation tube for detecting LPRM signal in a core of the reactor. A GT assembly is housed in the tube. The GT assembly has fixed GT detectors for detecting .gamma.-ray heating values and a built-in heater therein for calibrating the fixed GT detectors. The fixed GT detectors are arranged at least close to the fixed LPRM detectors, respectively. GT signals by the detected .gamma.-ray heating values of the fixed GT detectors of each GT assemblies are processed by a GT signal processing unit. The heater in each GT assemblies is electrically energized by a GT heater control unit. Predetermined time intervals are stored in a memory unit. One of the predetermined time intervals for specified .gamma.-ray thermometer assemblies, respectively is selected so that the GT heater control unit controls an electrical energy supplied to the heater by the selected interval so as to heat the heater, thereby executing a heater calibration of output voltage sensitivities of the fixed GT detectors of the GT assembly.

Inventors: Hirukawa; Koji (Kanagawa-Ken, JP)

Assignee: Kabushiki Kaisha Toshiba

International Classification: G21C 17/10 (20060101); G21C 17/108 (20060101); G21C 017/00 ()

Expiration Date: 10/30/2018