Rapid analysis of Sr compounds for nuclear forensics

Prof. Sungyeol Choi from the Department of Nuclear and Quantum Engineering (NQe) is developing a rapid analysis method without sample preparations to detect Sr compounds for nuclear forensics and radioactive waste management. Single-shot laser-induced breakdown spectroscopy (LIBS) can detect the thin layers of Sr compounds on metals, porous medium, and transparent materials that are commonly produced from the nuclear power industry, medical applications, and industrial uses.

Article | Fall 2020

Professor Sungyeol Choi, an assistant professor of nuclear and quantum engineering at KAIST, has developed a new rapid detection method without sample preparations to confirm the presences and concentrations of Sr compounds on the surfaces of solid radioactive waste or nuclear forensics samples. The thin layer of Sr on the samples makes single-shot analysis essential. This LIBS detection of Sr can be used to analyze threats and collect information rapidly in radiological crime scenes as well as radioactive waste treatment facilities.

Rapid threat analysis without sample preparations during radioactive waste treatment facilities as well as radiological crime scenes is essential to provide safety-related information quickly for protecting inspectors and the public. In particular, this study focuses on analyzing Sr compounds. Unfortunately, there were several cases of ⁹⁰Sr being stolen in the former Soviet Union, where strict protection protocols were missing. The analysis of ⁹⁰Sr is time consuming using conventional detection methods because it only emits beta particles. The emitted particles interact with matter and stop within a short distance. In addition, measuring Sr over large areas or across various materials will take a very long time. The complicated sample preparation will still require long processing times of up to several days.

The rapid analysis of Sr compounds without sample preparations can be achieved in a distance by laser-induced breakdown spectroscopy (LIBS). With long-distance detection, the investigators at the terror scenes can be protected from radiation. Only a few seconds are required to analyze material compositions over a narrow sample spot with a diameter of about 100㎛. The layer of Sr on the surfaces of forensic samples is thin, rendering the use of multiple pulses obsolete, which makes single-shot analysis essential. Single-shot LIBS can measure the elemental and molecular compositions of the thin layers of Sr compounds, down to a few ㎍/cm², on metals, porous mediums, and transparent materials.

 

Prof. Sungyeol Choi noted, “It is important to detect materials of concerns in a distance for protecting inspectors and the public in radiological crime scenes; moreover, this method can be applied for rapidly detecting Sr compounds on a volume of radioactive wastes produced from the nuclear power industry, medical applications, and industrial uses.”

Mr. Yunu Lee, who is a Ph.D. student in KAIST nuclear and quantum engineering, participated as the first author of the recently published paper entitled “Rapid identification of Sr on surfaces of metals, porous medium, transparent materials using single-shot laser-induced breakdown spectroscopy” in Spectrochimica Acta Part B: Atomic Spectroscopy (doi.org/10.1016/j.sab.2019.105649).