Relationship of 220Rn and 222Rn progeny levels in Canadian underground U mines.

Radon-222 and 220Rn progeny are found in some Canadian underground U mines. Because both can contribute to lung dose, their experimental determinations are important. The relationship between 222Rn progeny Working Level [WL(Rn)] and 220Rn progeny Working Level [WL(Tn)] has been investigated in U mines. Experimental measurements extended from 1981 to 1986 and consisted of about 700 measurements of each WL(Rn) and WL(Tn). The data were analyzed by standard linear and power-function regression analysis. A power-function relationship between WL(Rn) and WL(Tn) seemed to fit the experimental data best. The relationship obtained permits the calculation of WL(Tn) from experimental values of WL(Rn). The relationship is useful for lung-dose-calculation purposes and in mine-ventilation-engineering calculations.