Application of thermoelectric cooling module for sampling of tritium in air

The sampling and measurement of airborne tritium is an essential component of workplace monitoring at heavy water handling facilities and nuclear reactors using heavy water as coolant and moderator. Tritium being an internal hazard, its workplace monitoring and assessment of internal exposure of workers is a regulatory requirement for the facility. The conventional tritium air sample collection methods are condensation, bubbling, and trapping with appropriate media such as dry ice, water, and desiccants, respectively. A novel method for rapid collection of moisture in the air for the estimation of tritium is presented and discussed in this article. It involves condensation of tritium oxide in the air using a commercially available thermoelectric cooling module which has removed uncertainty in the availability of dry ice or desiccant. The instrument is capable of collecting 2–3 ml of sample in 30 min at a relative humidity level of about 60% and temperature of about 25.5°C. The quantity of sample collected is sufficient for the estimation of tritium concentration in air. The Peltier module-based low-cost, simple, and reliable system has been successfully implemented for workplace tritium in air sampling at radiological facilities.