14CO2-in-air sampling with passive diffusion samplers.

Passive diffusion samplers designed for measuring HTO-in-air have been evaluated for measuring 14CO2-in-air. Controlled exposures to HTO-in-air, 14CO2-in-air, and a combination of the two gases were carried out. The sampling rate of the 14CO2-in-air was found to be approximately 0.7 that of HTO-in-air. This value is consistent with the calculated relative sampling rates based on the diffusion coefficients of the gases. Passive diffusion samplers currently used for sampling HTO-in-air at CANDU facilities have been shown to be suitable for also measuring 14CO2-in-air and HTO-in-air simultaneously when prepared with the appropriate sampling solution.