To ensure the maintenance of a safe working environment, and provide data of interest to operations personnel, a fixed air sampling system (FASS) has been installed at the Hot Fuel Examination Facility/North at Argonne National Laboratory's Idaho site. A design requirement is that the system be operated with a minimum number of personhours. Sixty-six sampling stations are located throughout the facility to gather data from areas where personnel are normally present without respiratory protection. The effectiveness of in-cell contamination-control programs and materials-handling procedures can be evaluated. Long-term trends are valuable guides to improving radiological controls while airborne activities are still well below operational guidelines. Since the beginning of operation in August 1976, the concentrations have averaged between 1 x lo-'' and 5 x to 4 X pCi/cm3 for P-y emitters Such values are well below the radiation concentration guides. pCi/cm3 for (Y emitters and from 4 X