On February 28, 1996, at the Savannah River Central Laboratory, two workers received high radiation exposure when they removed a flanged pipe tee from an outof-service drain line. They had signed in on a work package that specified installation of new piping only in an area posted and controlled as a high radiation/high contamination/airborne radiation area. After the piping was removed, no work was conducted in the area until March 4 when a radiological control inspector surveying the area detected a whole-body dose rate of 40 mrem/hour at 30 centimeters, a skin dose rate of 1,000 mrem/hour at 30 centimeters, and an extremity dose rate of 15,000 mrem/hour at contact in the open end of the drain pipe. Violation of work control package instructions and failure to perform surveys while in a controlled radiological area resulted in worker exposure to radiation levels greater than work suspension limits of the Radiation Work Permit (RWP). (ORPS Report SR--WSRC-ALABF-1996-0002)
The workers were installing new piping in the shielded area of the Central Laboratory when they determined that a two-inch stainless steel drain pipe with a flanged pipe tee was obstructing their installation. They informed the facility operations engineer and their supervisor who both approved the removal of the flanged tee. The workers also obtained concurrence from the radiological control inspector on the need to remove the tee. They signed in on the RWP that limited the scope of work to installation of new pipe. The workers removed the tee and installed the new piping, which extended over and beyond the open drain pipe. Radiological control technicians did not conduct a survey after removal of the tee. The facility manager independently stopped work in the area until March 4.
Investigators determined that the root cause of this event was inadequate administrative control. Neither the operations engineer, the workers? supervisor, nor the radiological control inspector recognized the significance of the change in job scope from installation of new, uncontaminated drain piping. Investigators determined that the direct cause of this event was that the procedure was not used or was used incorrectly. Removing the flanged tee was not included in the RWP and radiological control measures and precautions established for the task were inadequate.
The facility manager directed the work plan for the job to be re-evaluated and the RWP be revised. He also ordered a briefing for the operations and radiological control staff on radiological work permit requirements with emphasis on the need to be alert for changes in job scope during performance of the work.
Through isotopic analysis, the radiological control technical staff determined that the radionuclides were plutonium-238 and plutonium-239. Using dosimetry from the workers and the surveyed dose rates, they established the workers? extremity dose at 375 mrem.
DOE/EH-0256T, Radiological Control Manual, section 321, states that the RWP establishes radiological controls for intended work. Failure to follow instructions sets the stage for unplanned exposures and unsafe working conditions. DOE facility managers should review, with their operators and radiological control technicians, the importance of being alert to changes in job scope during the performance of a work package.
KEYWORDS: procedure, radiological, violation, work control
FUNCTIONAL AREA: radiation protection