Nuclear Techniques ›› 2019, Vol. 42 ›› Issue (12): 120401-120500.doi: 10.11889/j.0253-3219.2019.hjs.42.120401

• NUCLEAR ELECTRONICS AND INSTRUMENTATION • Previous Articles     Next Articles

Development of a successive yield measurement system for airborne radioiodine generation using NaI(Tl) spectrometer

Jiayu XIN Zhiwei LI Xiaoshuang HE Linfeng TANG Fangdong ZHAO Chao LIU   

  1. Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
  • Received:2019-10-24 Revised:2019-11-11 Online:2019-12-10 Published:2019-12-18
  • Supported by:
    National Natural Science Foundation of China(11605113)

Abstract: Background

Environment airborne radioiodine monitoring is important for the operation of nuclear power plants and public nuclear safety. The airborne radioiodine generation technique is essential for airborne radioiodine research, including its measurement technology and behavior characteristics. Although many airborne radioiodine generation techniques have been developed, little attention has been paid to higher performance generation techniques and detailed understanding of the generation process.

Purpose

This study aims to develop a successive airborne radioiodine generation measurement system.

Methods

Two series-connected collection containers, two NaI(Tl) spectrometers, and one computer with self-developed software, were employed for the composition of this successive yield measurement system. In the process of airborne radioiodine generation, the series-connected collection containers were connected with the generation container for continuous airborne radioiodine collection whilst the NaI(Tl) spectrometers monitored radioiodine in the collection containers and generation container in real time. Meanwhile, the measured spectrum was sent to the computer and analyzed by self-developed software. Hence the change of yield with time during the generation of the airborne radioiodine could be reflected by the software. The major influences in the measurement were also discussed theoretically and experimentally, including interference of measurements between radioiodine in different containers and inconsistencies between radioiodine collection containers. Finally, the uncertainty analysis of this measurement result under typical working conditions was performed.

Results

This measurement system was applicable to various airborne radioiodine generation techniques including inorganic iodine, organic iodine and aerosol iodine. The measurement period was adjustable. Considering the measurement frequency and uncertainty, the recommended measurement period was 20 s. Under typical working conditions, the expanded uncertainty of the measured yield was 2.5% (k=2) while yield was 90%.

Conclusions

This successive yield measurement system could be used to observe the detailed process of airborne radioiodine generation, and provide a powerful tool for the optimization of airborne radioiodine generation techniques.

Key words: Airborne radioiodine, 131I, Successive yield measurement, Uncertainty analysis

CLC Number: 

  • TL84,TL75+1