On October 27, 1994, a worker at the Lawrence Livermore National Laboratory was contaminated on the face and chest when he disconnected a line pressurized with contaminated air. The worker believed that the line had been depressurized. Facility personnel responded quickly and appropriately by securing the area and decontaminating the worker. No other workers were contaminated as a result of this event. (ORPS Report SAN--LLNL-LLNL-1994-0069)
Two workers at the Plutonium Recovery Laboratory were trying clear a blocked one half inch stainless steel vacuum line. One worker was a Certified Plutonium Handler (CPH), the other was a Limited Plutonium Handler (LPH). Both workers were wearing appropriate protective clothing as required by the laboratory procedures. They were trying to remove fluid from the vacuum service line by blowing compressed air through the line and into a glovebox. The CPH connected the line to a compressed source and cycled the compressed air supply valve several times in an effort to clear the blocked line. After the LPH saw liquid and particulate issue from the line, both workers mistakenly believed that the line was clear. The CPH removed the compressed air tygon tubing from the nozzle of the vacuum line. This released the air pressure from the blocked line and sprayed the CPH with contaminated air. He felt a puff of air on his face, surveyed his gloved hands, and detected contamination.
A Health and Safety Technician surveyed the CPH and detected approximately 20,000 dpm (100 sq. cm probe area) on his forehead above the left eye, and 10,000 dpm on his chest. Health and Safety Technicians removed gross levels of contamination from the CPH's face. A preliminary radio-assay of the CPHs nose swipes was positive. Health and Safety Technicians performed a lung count with negative results. All the contamination was determined to be alpha emitting radioactive material. No other personnel were contaminated as a result of this event.
The laboratory is currently evaluating procedural controls to determine if they can be improved to prevent future accidental contaminations. In addition, the laboratory is evaluating the feasibility of attaching moisture removal devices to the vacuum lines to prevent moisture buildup in the future.
In general, personnel working at DOE facilities need to be aware that they should position themselves out of the path of potential fluid discharges when opening piping and tubing systems to prevent accidental exposure or contamination.
Article 313 of the DOE/EH-0256T, Radiological Control Manual, addresses infrequent or first-time radiological activities. Special management attention is required when planning these activities. This attention should include:
Formal radiological review, Senior management review, Review and approval by the ALARA Committee, and Enhanced line and radiological management oversight.