Results of the radiological characterization survey of the Building 7819 Decontamination Facility at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Abstract

A radiological characterization survey of the interior of the Building 7819 Decontamination Facility at Oak Ridge National Laboratory (ORNL) was conducted during July 1993. The interior of Building 7819 is grossly contaminated, and the contamination is highly transferable. Levels of alpha and beta contamination inside the building exceed ORNL guidelines for zoning as a Contamination Area. Gamma whole-body exposure rates generally ranged from 0.1 to 20 mR/h. Total beta-gamma surface contamination ranged from 1,000 to 520,000 dpm/100 cm{sup 2}, and transferable beta-gamma contamination ranged from 200 to 174,000 dpm/100 cm{sup 2}. A pump and a metal table near the pit exhibited beta dose rates of 3 rad/h and 300 mrad/h, respectively, and gamma exposure rates of 250 mR/h and 25 mR/h at contact, respectively. Total alpha contamination levels ranged from 100 to 110,000 dpm/100 cm{sup 2}, and transferable contamination ranged from 21 to 440 dpm/100 cm{sup 2}. The ledge at the north end of the pit above the sink demonstrated alpha contamination of approximately 100,000 dpm/100 cm{sup 2}. Radionuclide analysis of 11 smear samples showed the primary beta emitters to be {sup 90}Sr and {sup 137}Cs with trace amounts of {sup 60}Co. The Building 7819 Decontamination Facility was zoned asmore » a Contamination Area and Radiation Area at the time of this survey, and the zoning is justified by the results of the survey. The building will also be zoned as an Airborne Radioactivity Area, based on the results of air sampling. Recommendations for corrective actions are included.« less