Online measurement method for three-dimensional power distribution of reactor core

Abstract

The invention provides an online measurement method for the three-dimensional power distribution of a reactor core. The method includes the steps that 1, an existing reactor core is modeled, follow-up analog computation is carried out on the modeled reactor core and an operating history thereof in combination with reactor core state parameters measured online, and theoretical three-dimensional power distribution is obtained; 2, radial correction is carried out on the theoretical three-dimensional power distribution with online measurement data of a reactor core outlet thermocouple in combination with a thermocouple calibration coefficient, and corrected three-dimensional power distribution is obtained; 3, axial correction is carried out on the corrected three-dimensional power distribution with ex-reactor detector data measured in real time online in combination with an ex-reactor detector calibration coefficient, and measured three-dimensional power distribution is obtained. According to the method, the reactor core outlet thermocouple measurement data and the ex-reactor detector measurement data are reasonably utilized, high-precision LPD and DNBR are obtained online, the operating margin of a reactor is directly monitored with early warning given, and the economy and safety of a nuclear power plant are improved.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor core monitoring, control and protection, in particular to an online measurement method for three-dimensional power distribution of the core. Background technique [0002] Such as figure 1 As shown, the reactor core active region 02 is an area composed of a plurality of fuel cell assemblies 03 contained within a steel pressure vessel 01 . The pressure vessel 01, the steam generator 13, the main pump 16 and related pipeline equipment constitute a closed coolant circuit, called the primary circuit. The closed circuit composed of the secondary side of the steam generator 13, the steam pipeline, the steam turbine 15 and related equipment is called the secondary circuit. [0003] Since the active zone of the reactor core requires that thermal safety criteria must be guaranteed, such as no fuel cell assembly 03 pellet melting and cladding not failing due to nucleate boiling, it is required that...

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Problems solved by technology

However, one disadvantage of this technical solution is that using the technology of the LSS system, the detectors outside the reactor can be directly converted to the average axial power distribution of the whole reactor. Since the T matrix and the S matrix cannot directly integrate the reactor inside-outside Usually, a COR matrix needs to be added to the LSS system to correct the influence of the axial control rods on the power distribution. Whether the COR matrix is ​​generated using a pre-defined theoretical library or online theoretical calculation, it will lead to axial power distribution. Refactored accuracy drops

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