Detectability of Tritium Isotopologues HTO and T2O in Radioactive Water Vapors by IR Spectroscopy

Large amount of tritium, which is a radioactive isotope of hydrogen and is hazardous to all living things, enter the environment from anthropogenic sources, including accidents at nuclear power plants. Monitoring of tritium in water and air is very important for assessing environmental and radiation risks. Our study is devoted to the development of an infrared (IR) spectroscopy-based trace method for monitoring tritium isotopologues of water (HTO and T2O). The main objective is to estimate the sensitivity of IR spectroscopy for detecting low concentrations of HTO and T2O in water vapors, which is critical for the operational monitoring of radioactive contamination. The transmission of the tritium isotopologues is simulated by line-by-line method at different concentrations. The spectroscopic data from theoretical calculations and experimental measurements, including absorption line parameters from spectra.iao.ru and HITRAN2020 databases, are used in the simulation. The line broadening coefficients were refined with the use of the authors’ technique. The main results of this work include: improved line broadening parameters, which provide an increase in the simulation accuracy; revealed optimal spectral regions for detecting HTO (1227–1236 and 2219–2226 cm−1) and T2O (930–990 and 1092–1100 cm−1) in the atmospheric transparency window 8–12 μm; estimated detection threshold for tritium isotopologues at a level of 0.01–0.05% of the concentration of the main isotopologue H216O. The results open up opportunities for creating real-time tritium monitoring systems. Promising areas for further research are adaptation of the method to field conditions with allowance for the atmospheric effect and integration of spectroscopic data into climate models. The work contributes to the development of environmental monitoring and radiation safety methods.