Nuclear Science and Techniques ›› 2019, Vol. 42 ›› Issue (3): 30301-030301.doi: 10.11889/j.0253-3219.2019.hjs.42.030301

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Determination of 228Ra in environmental water by liquid scintillation spectrometry

Mingming XIA1,Guobing YU2,Deyun WEN2,Xianbao GU2,Yuan WANG1,Yongguang LIANG1,Qifan WU3,Zhi CHEN1()   

  1. 1. University of Science and Technology of China, Hefei 230027, China
    2. Anhui Environmental Radiation Supervision Station, Hefei 230071, China
    3. Tsinghua University, Beijing 100084, China
  • Received:2018-06-24 Revised:2019-01-03 Online:2019-03-10 Published:2019-03-14
  • Contact: Zhi CHEN E-mail:zchen@ustc.edu.cn
  • About author:<named-content content-type="corresp-name">XIA Mingming</named-content>, female, born in 1994, graduated from Zhengzhou University in 2016, master student, focusing on nuclear detection and radiation protection|<named-content content-type="corresp-name">XIA Mingming</named-content>, female, born in 1994, graduated from Zhengzhou University in 2016, master student, focusing on nuclear detection and radiation protection|CHEN Zhi, E-mail:<email>zchen@ustc.edu.cn</email>
  • Supported by:
    Supported by Ministry of Ecology and Environment Project(No.1705);Supported by Ministry of Ecology and Environment Project (No.1705)

Abstract: Background

228Ra is the first decay daughter of 232Th decay chain, it is a low energy β radio-nuclide.

Purpose

To analyse low activity 228Ra in environmental water.

Methods

The process of concentrating 228Ra in water is carried out using Ba(Ra)SO4 co-precipitation method. The stable Ba is measured by atomic absorption spectroscopy (AAS) to determine the yield of 228Ra under the carrier tape. The ultra-low background liquid scintillation spectrometer (LSC) is used to measure the Ra-concentrated samples, and more accurate and low activity analysis result were obtained.

Results

The yield of 228Ra obtained via the Ba(Ra)SO4 co-precipitation method was in the range of 59%~90%, and the detection limit of 228Ra was 7.9 mBq·L?1 (1 L sample, measurement time t=20 h). As for two types recoveries of 228Ra, the relative deviation between 133Ba tracer method and atomic absorption spectrometry method is within 7%. The counting efficiency of LSC on 228Ra/228Ac is 72.9%. The relative deviation of the spiked water sample measurement is 1.0%~10%.

Conclusions

This method can achieve more accurate measurement of low activity 228Ra in water.

Key words: 228Ra, LSC, Ba(Ra)SO4 co-precipitation, Yield, Atomic absorption spectroscopy

CLC Number: 

  • TL99