核电厂便携式低放废水在线监测设备关键技术探讨

摘要/Abstract

摘要： 结合核电厂的实际情况和需求,梳理了低放废水的特点,明确了其对便携式在线监测设备的技术要求,其中最关键是能同时满足低探测下限(MDAC≤8 Bq/L)和便携性(设备总重≤50 kg)的限制。讨论了测量方式、探测器选型和校准方式等在线监测设备的关键技术,对低放废水进行了放射性在线监测,测量方式选择取样式,探测器选择大体积NaI晶体,校准方式选择代表点法。调研了低放废水在线监测设备的研究现状,现有的在线监测设备重量都在200 kg以上,与核电厂的要求之间存在较大的差距,有必要开展同时具备低探测下限和优异便携性的新型在线监测设备的研制。对新型探测器的应用、结构和新型测量方式的发展这三个研究方向给出了建议。最后,从提高探测效率的角度,提出了一种基于环形NaI晶体的新型探测器结构,初步论证了其探测下限和设备总重指标有望满足核电厂的要求。

关键词: 核电厂, 低放废水, 在线监测设备, 便携式

Abstract: Based on the situation and demand of a NPP, the features of LLRW are summarized. The technical requirements for portable online radioactive monitoring equipment are specified. The most important requirement is to meet the low detection limit (minimum detectable activity concentration, MDAC≤8 Bq/L) and portability of the equipment (total weight of the equipment should be≤50 kg). Key technologies such as measurement mode, detector selection and calibration method are then discussed. The measurement mode is generally sampling mode. The detector is generally large volume NaI crystal. The calibration methods are usually standard liquid source method and representative point method. Finally, the current online monitoring equipment for LLRW is investigated. It is found that the weights of all the existing equipment are more than 200 kg, which is far from the requirement of NPPs. Therefore, it is necessary to develop new on-line monitoring equipment with low MDAC and excellent portability. Three research directions are suggested, which are the application of new detector types, the development of new detector structure, and the development of new measurement methods. In order to improve the detection efficiency, a new detector structure based on annular NaI crystal is proposed. The weight of the new equipment and the MDAC is discussed preliminarily. It is expected to meet the requirements of NPPs.

Key words: nuclear power plant, low-level radioactive waste water, on-line monitoring equipment, portable

中图分类号:

TL812

周建旺, 尤成懋, 梅翔杰, 周克波, 张素杰, 尹旺明. 核电厂便携式低放废水在线监测设备关键技术探讨[J]. 辐射防护, 2024, 44(4): 349-355.

ZHOU Jianwang, YOU Chengmao, MEI Xiangjie, ZHOU Kebo, ZHANG Sujie, YIN Wangming. Discussion on key technologies of portable on-line monitoring equipment for low-level radioactive waste water in NPPs[J]. RADIATION PROTECTION, 2024, 44(4): 349-355.

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