On January 13, 1995, three workers at the H-Canyon facility at the Savannah River Site were contaminated when they poured plutonium solution from sample vials into a drain system. This action exceeded the scope of work in the radiological work permit (RWP) and resulted in a release of airborne contamination. The contamination was limited to the area surrounding the sample box. Facility management stopped all radiological work activities and work requests are subject to technical review by the Operations Manager. (ORPS Report SR--WSRC-HCAN-1995-0001)

Two operators and one Radiological Controls Inspector (RCI) were assigned to dispose of "dummy" sample vials from a sample box. Dummy sample vials are samples that may not adequately represent the contents of a sampled tank. They may not have enough volume for lab analysis or they may too diluted with flush water. The sample box is used to draw solutions from the final product hold tank before the contents are transferred to the HB-Line facility. Seven sample vials were to be transferred to a waste box for future processing. Past practice was to remove the vials from the box at the time that the samples were taken and return them to the laboratory for processing. However, recently, personnel began leaving the vials in the box until the number of vials began to interfere with sample-taking process.

During the pre-plan meeting, the three workers discussed the need to pour the solution down the sample box drain, which drains to the Hot Canyon cell floor. They did not recognize that the solutions from this tank could cause air activity to exceed the limits for the prescribed respiratory protection. The RWP had been written based on removing the vials from the sample boxes, and did not address pouring the solution down the drain. No technical documentation or procedures, other than the RWP, was available for this activity. Again, past practice allowed operators to dump the contents down the sample drain. Recently, managers discouraged this practice because it added contamination to the canyons.

The work suspension guide limit for the RWP was established at 50 Derived Air Concentration (DAC) for the existing radiological conditions. All three personnel wore protective clothing as prescribed by the RWP that included two pairs of coveralls, four pairs of rubber gloves, and full-face respirators. When the operators poured the last vial down the drain, the RCI checked the air activity and found it to be 772 DAC. The final vial contained a diluted plutonium product. The RCI stopped work and immediately evacuated personnel upwind of the sample box since the suspension limits were exceeded. RCIs surveyed the workers' protective clothing and found alpha activity on the outside of the respirator of the RCI. They also found alpha activity of 35 dpm inside the respirator of the operator who performed the work. The three workers submitted nasal and saliva smears and the results were negative. As a precautionary measure, radiological controls personnel placed the three personnel on a fecal and urine bioassay program.

Facility management is considering several corrective actions. They include suspending the practice of dumping samples into canyon drains, periodically inspecting sample boxes to determine if vials are left in the sample boxes, removing the vials currently in the boxes, and increasing the level of technical review for radiological work activities.

A facility representative indicated that a lesson learned is that facility workers should not use RWPs to provide technical guidance on specific tasks. Articles 311, 312, 315, and 316 of DOE/EH- 0256T, Radiological Control Manual, require separate technical documents such as procedures for performing radiological work activities and such documents require comprehensive technical reviews by the site's radiological control organization. Had a comprehensive technical review of the work activity been performed, this event could have been prevented.