基于动态氙条件的单点校刻技术研究及应用

During the power-elevation after refueling overhaul, the nuclear power plant will carry out calibration test of ex-core power range detector (referred to as ex-core detector) at the specified power level to indicate the accurate core power level and axial power deviation. This paper proposes an ex-core detector calibration method based on dynamic-xenon condition. Based on the single core flux measurement test under dynamic xenon condition, and combined with the dynamic xenon theoretical library provided by the core physical analysis code SPARK, the core power is reconstructed, and then the calibration of the ex-core detector is completed by single-point calibration. The long waiting time for xenon equilibrium isn’t required in the whole process, which has high economic benefits. The method is verified by the measured data of Unit 5 in Tianwan Nuclear Power Station during power elevation in the second overhaul, and the errors of power level and axial power deviation are all within ±1.0% and ±0.5%, respectively. The verification results show that the single-point calibration method proposed in this paper can complete the calibration of ex-core detector within 2 h after the specified power level is reached, and the calibration coefficient has high calculation accuracy.