Retention of uranium thorax burdens in fuel fabricators

Internal contamination of Canadian nuclear fuel workers has been detected for many years by means of urinalysis. While urinalysis results, if properly interpreted, can yield considerable information concerning the efficacy of contamination control in the plant, they do not offer much help in estimating the individual's body burden of uranium. For this, direct in vivo measurements are required. During the last 2 years a large number of the production and maintenance personnel at these plants have undergone in vivo measurements for thorax burdens of uranium, many of them several times. Since the fuel produced is for the CANDU reactor, the uranium is not enriched. The variation of these thorax burdens with time is the subject of this paper. (author)