On-Line Monitoring of Radiocarbon Emissions in a Nuclear Facility with Cavity Ring-Down Spectroscopy

• Published in: Analytical chemistry (Washington) 2021-12, Vol.93 (48), p.16096-16104
• Main Authors: Lehmuskoski, Johannes, Vasama, Hannu, Hämäläinen, Jussi, Hokkinen, Jouni, Kärkelä, Teemu, Heiskanen, Katja, Reinikainen, Matti, Rautio, Satu, Hirvelä, Miska, Genoud, Guillaume
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Analytical chemistry; Cavity ringdown; Chemistry; Emissions; Environmental Monitoring; Gases; Industrial plant emissions; Infrared spectroscopy; Nuclear facilities; Nuclear power plants; Pollution monitoring; Radioactive emissions; Spectroscopy; Spectrum Analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.1c03814

There are currently no suitable methods for sensitive automated in situ monitoring of gaseous radiocarbon, one of the main sources of radioactive gas emissions from nuclear power plants. Here, we present a transportable instrument for in situ airborne radiocarbon detection based on mid-infrared cavity ring-down spectroscopy and report its performance in a 1-week field measurement at the Loviisa nuclear power plant. Radiocarbon is detected by measuring an absorption line of the 14CO2 molecule. The time resolution of the measurements is 45 min, significantly less than the few days’ resolution of the currently used technique, while maintaining a comparable sensitivity. The method can also assess the prevalence of radiocarbon in different molecular species in the airborne emissions. The optical in situ monitoring presented is a completely new method for monitoring emissions from nuclear facilities.