Recommended radiological air sampling and internal contamination control at nuclear power plants

It has long been recognized by the NRC technical staffs that estimating the quantity of radioactivity inhaled by an individual worker involved large uncertainties. General air samples usually produce concentrations lower than those in the workers breathing zone (BZ). NRC guides have recognized this problem by specifying air monitoring programs which sample the breathing zone or concentrations known to be higher than that actually inhaled. In addition the availability of suitable samplers to obtain BZ samples and the practicality of requiring their use was somewhat in question to the NRC technical staff. An NRC development contract was issued to provide a detailed review of the technical aspects of the problems and recommendations for practical upgrade of Federal Guidance. This project accomplished a review of the nuclear industry experience and knowledge though a literature search, site visits to representative licensed facilities, telephone surveys of many others, laboratory testing of personal air samplers (lapel samplers) and aerosol diffusion experiments to verify key conclusions and assumptions. Findings and conclusions are presented