On April 26, 1993, the shoes of two operators were contaminated and loose contamination was found outside of a radiologically controlled area while moving packages containing radioactive waste from a storage area to another building at the Hanford Plutonium Finishing Plant. Operators were using a forklift and wooden pallet to move the packages, which contained waste generated during a building cleanout in the 1986 time frame. The packages were being transferred from the storage area to the canyon airlock for placement in burial boxes. Health Physics Technicians also detected contamination on the pallet, on the ground outside the airlock, and on the pavement outside the storage area.
During the transfer, a Health Physics Technician surveyed each package of waste before it was loaded on the pallet. No contamination was detected. While off- loading the packages from the pallet to the airlock, an operator detected contamination on his shoe cover (5,000 disintegrations per minute - dpm, alpha). After removing the shoe cover, he also detected contamination on his shoe. The Manager, Material Storage immediately directed all personnel involved in the movement of the waste packages to perform surveys. A second operator, who had been working outside the storage area placing waste packages on the pallet, also detected contamination on one of her shoes (300 dpm alpha). Health Physics Technicians responded by surveying the pallet and route taken by the forklift. The areas where contamination was found outside the radiologically controlled areas were sealed (taped or painted) to prevent the spread of contamination. The pallet was placed inside a plastic cover.
Facility personnel identified a package containing a table as the cause of the contaminations. Although the corners and discernible sharp edges were taped prior to moving the package, three holes were discovered during decontamination surveying. The holes apparently resulted from stress during movement of the package. (ORPS Report RL--WHC-PFP-1993-0026; Richland Daily Operation Report, 4/27/93, Fact Sheet No. 1)
This event underscores the need for facility personnel to take special precautions when moving large, bulky packages of contaminated waste, especially when the contents have sharp edges or protrude from the packaging. Additional layers of packaging material at the sharp or protruding areas should be considered, as well as extra measures to minimize movement and shifting of the package contents while being transported.