Apparatus, method and program for monitoring nuclear thermal hydraulic stability of nuclear reactor

A method for monitoring nuclear thermal hydraulic stability of a nuclear reactor, comprising the steps of:

• calculating a stability index of a nuclear thermal hydraulic phenomenon based on nuclear instrumentation signals, the signals being outputted by a plurality of nuclear instrumentation detectors placed at regular intervals in a reactor core;
• simulating the nuclear thermal hydraulic phenomenon based on a physical model by using information on an operating state of the reactor as an input condition;
• updating a limit value of the nuclear thermal hydraulic phenomenon based on a result of the simulation;
• and
• determining, based on the stability index and the limit value, whether or not to activate a power oscillation suppressing device.

A program for monitoring nuclear thermal hydraulic stability of a reactor to be executed by a computer that performs functions of:

• calculating a stability index of a nuclear thermal hydraulic phenomenon based on nuclear instrumentation signals, the signals being outputted by a plurality of nuclear instrumentation detectors placed at regular intervals in a reactor core;
• simulating the nuclear thermal hydraulic phenomenon based on a physical model by using information on an operating state of the reactor as an input condition;
• updating a limit value of the nuclear thermal hydraulic phenomenon based on a result of the simulation;
• and
• determining, based on the stability index and the limit value, whether or not to activate a power oscillation suppressing device.