Ratio of nose blow results to intakes during the decommissioning of a facility at Dounreay

Abstract

During the decommissioning of a large glove box facility at Dounreay, in addition to engineering and administration controls, workers wore pressurised suits to minimise their intake of radionuclides. The workers provided nose blows after each suited operation to provide an indication of the effectiveness of protective measures. The nose blows were also used as indicators of radiological significant intakes. This paper examines the distribution of ratios of nose blow to assessed intake. A geometric mean and variance of the ratio of nose blows to intakes have been derived. The nose blows were provided over a period of 2 y and the alpha-emitting nuclides present are 239Pu, 241Am and 238Pu. Twenty-two nose blow results each with follow-up urine and faecal results are included in the study. The effectiveness of nose blows as an indicator of radiological conditions and as a trigger for the investigation of significant doses is considered. The ratio between assessed intake and nose blow result was shown to be very large.