Formerly Utilized MED/AEC Sites Remedial-Action Program. Radiological Survey of Ryerson Physical Laboratory, The University of Chicago, Chicago, Illinois, September 11-25, 1976

摘要

A comprehensive radiological survey was conducted at the Ryerson Physical Laboratory at the University of Chicago, Chicago, Illinois. General radiochemistry and/or physics research was performed at this facility during the MED/AEC era in the 1940s. The building is now used as laboratories, offices, and classrooms. The survey was undertaken to determine the location and quantities of any radioactive materials remaining from the MED/AEC activities. Forty spots of contamination in 26 rooms possibly resulting from MED/AEC occupancy exceeded the allowable limits as given in ANSI Standard N13.12 for Group 1 nuclides. The potential for radiation exposure to occupants of this building from these sources of contamination is remote under current use conditions. Concentrations of radon daughters in the air of the building were less than the limit of 0.01 WL above background as given in the Surgeon General's Guidelines. Concentrations of radionuclides in soil samples collected around the facility indicated background levels. The presumed maximum potential dose for external penetrating radiation resulting from exposure to the radioactivity remaining from MED/AEC operations was calculated to be 140 mrem a year, which is 30% of the 500-mrem standard for an individual in an uncontrolled area. In order to reduce the potential for radiation exposure, remedial measures such as stabilization of the contamination in place would be applicable as a short-term measure. In order to reduce the risk in the event that building modifications take place in the future, health physics procedures and coverage are recommended. The long-term solution would involve decontamination by removal of the radioactive residues from the 26 rooms or areas where contamination possibly resulting from MED/AEC activities was detected. (ERA citation 07:049408)