Nuclear Technology & Radiation Protection Journal


NT & RP Journal	RESEARCH ON LEAK MONITORING OF THE PRIMARY CIRCUIT OF A PRESSURIZED WATER REACTOR BASED ON THE ¹³N COINCIDENCE METHOD
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Vol. XXXVII, No. 4, Pp. 259-339 December 2022 UDC 621.039+614.876:504.06 ISSN 1451-3994 Back to Contents	Pages: 308-314 Authors: Yue Zhao, Guo P. Qu, and Jian L. Zhou Abstract To assess the characteristics of ¹³N decay, a monitoring method of the primary loop leakage rate based on the γ-γ coincidence method was proposed. In this work, sampling and measurement devices were designed, in which NaI (Tl) crystals were used as coincidence detectors. The Geant4 simulation method was used to study the relationship between the efficiency ɛ and capacity V change of different devices, and the ɛV value under the corresponding capacity was obtained. According to the value of ɛV, the optimal sampling and measurement device was determined, and then the detection efficiency of the device was calibrated experimentally. Taking the 600.000 kW reactor of Qinshan Phase II as the research object, the lower limit of detection was discussed.When the sampling point was located in the fume hood of the control rod drive mechanism, the theoretical lower limit of the coincidence method was 0.756 Lh^-1. Key words: ¹³N, coincidence method, sampling and measurement device, detection efficiency, lower limit of detection FULL PAPER IN PDF FORMAT (730 KB)
Vinča Institute of Nuclear Sciences :: Designed by milas :: July 2007 Operated by acapanic :: Last updated on April, 2023

Pages: 308-314

Authors: Yue Zhao, Guo P. Qu, and Jian L. Zhou

Abstract

To assess the characteristics of ¹³N decay, a monitoring method of the primary loop leakage rate based on the γ-γ coincidence method was proposed. In this work, sampling and measurement devices were designed, in which NaI (Tl) crystals were used as coincidence detectors. The Geant4 simulation method was used to study the relationship between the efficiency ɛ and capacity V change of different devices, and the ɛV value under the corresponding capacity was obtained. According to the value of ɛV, the optimal sampling and measurement device was determined, and then the detection efficiency of the device was calibrated experimentally. Taking the 600.000 kW reactor of Qinshan Phase II as the research object, the lower limit of detection was discussed.When the sampling point was located in the fume hood of the control rod drive mechanism, the theoretical lower limit of the coincidence method was 0.756 Lh^-1.

Key words: ¹³N, coincidence method, sampling and measurement device, detection efficiency, lower limit of detection

FULL PAPER IN PDF FORMAT (730 KB)