A large buoy-based radioactivity monitoring system for gamma-ray emitters in surface seawater

Jong-In Byun; Seok-Won Choi; Myeong-Han Song; Byung-Uck Chang; Yong-Jae Kim; Ju-Yong Yun

doi:10.1016/j.apradiso.2020.109172

A large buoy-based radioactivity monitoring system for gamma-ray emitters in surface seawater

Appl Radiat Isot. 2020 Aug:162:109172. doi: 10.1016/j.apradiso.2020.109172. Epub 2020 Apr 8.

Authors

Jong-In Byun¹, Seok-Won Choi², Myeong-Han Song², Byung-Uck Chang², Yong-Jae Kim², Ju-Yong Yun²

Affiliations

¹ Korea Institute of Nuclear and Safety, 62 Gwahak-ro Yuseong-gu, 34142, Daejeon, Republic of Korea. Electronic address: k975bji@kins.re.kr.
² Korea Institute of Nuclear and Safety, 62 Gwahak-ro Yuseong-gu, 34142, Daejeon, Republic of Korea.

PMID: 32310092
DOI: 10.1016/j.apradiso.2020.109172

Abstract

A buoy (shallow water light type) -based in situ gamma-ray spectrometry system with a 7.6 cmØ × 7.6 cm NaI(Tl) detector for remote real-time monitoring of gamma-ray emitting radionuclides in surface seawater is presented. To convert measured count rates to radioactivity, the full energy peak efficiency of the detector for radionuclides in seawater was estimated using Monte Carlo simulation with the MCNP code. The efficiency calibration was validated by comparing the results with a sampling analysis of ⁴⁰K in seawater at the sites where the monitoring systems were deployed. The minimum detectable activity of the system for ¹³⁷Cs, ¹³⁴Cs and ¹³¹I with gamma-ray measurement time is discussed.

Keywords: Buoy; Gamma-ray spectrometry; MDA; Radioactivity; Real-time; Seawater.