Decommissioning a Medical Waste Incinerator Facility
S. M. Austin, R. A. Zoon, C. A. Ribaudo
Until May 1994 the National Institutes of Health (NIH) operated three medical pathological waste (MPW) incinerators for the destruction and volume reduction of MPW generated at NIH. A small fraction of the MPW contained low levels of radioactivity from patient care areas and research laboratories. NIH was authorized by the U.S. Nuclear Regulatory Commission (NRC) to incinerate radioactive materials. The NIH Radiation Safety Branch (RSB) conducted surveys of the incinerators, ancillary equipment, and potentially affected areas to determine if residual radioactivity remained from past licensed operations. A review of past incineration activities was conducted to determine which licensed radionuclides may be present in the building. Since decommissioning survey guidance had not been finalized by the NRC and the U.S. Environmental Protection Agency (NUREG-1575, "Multi-Agency Radiation Survey and Site Investigation Manual") at the time the decommissioning occurred, the approach was to use the guidance in NUREG CR-5849, "Manual for Conducting Radiological Surveys in Support of License Termination". Guidelines for acceptable residual radioactive contamination specified in NRC Regulatory Guide 8.23, Table 2, "Recommended Action Levels For Removable Surface Contamination In Medical Institutions" (Line 1, "Unrestricted Areas"), and Table 3, "Acceptable Surface Contamination Levels For Uncontrolled Release Of Equipment", were used to decide if cleanup of residual radioactivity was required. Equipment and areas that had the highest potential for radioactive contamination were identified and an initial scoping survey was conducted. Because of the low-likelihood of contamination, and the fact that the affected areas were well known at the time of the action, the scoping survey was designed more like a characterization survey. A thorough evaluation of the levels of residual radioactivity was to be determined during this first survey to save time and effort. It was decided that if no radioactive contamination above release guidelines was found during the scoping survey then no additional actions were to be taken. The equipment and building would be acceptable for unrestricted use. A second characterization survey would have been conducted in any areas where radioactive contamination was found above the release guidelines during the scoping survey. If contamination above the release guidelines was confirmed, decontamination of the affected equipment or areas would proceed. Final status surveys would then be conducted to assure that equipment or areas had been successfully cleaned to levels below the release guidelines.
This abstract was presented at the 35th Annual Midyear Meeting, "Decommissioning and Environmental Restoration", Decommissioning 3 Session, 2/17/2002 - 2/20/2002, held in Orlando, FL.