The project engineer fell off a temporary platform from a height of approximately 17 feet.
The accident occurred at approximately 11:20 a.m. on Tuesday, February 20, 1996, at the TSA-RE, Building 636, when a construction subcontractor Project Engineer fell approximately 17 feet from a temporary platform. The Project Engineer was employed by Caddell Construction Company, Inc. (Caddell), a subcontractor of LITCO.
The TSA-RE is a 313,000 square foot facility whose purpose is to provide year-round storage and retrieval of mixed transuranic contaminated waste containers stacked on asphalt pads within the building. The facility is constructed over stacked boxes and drums containing radioactive waste. The stacked waste (stack) is covered by a vinyl-coated, geo-fabric tarpaulin (fabric) supplemented with plywood over some portions. Much of the northern portion of the stacked waste is covered by earth. The southern portion of the stack is covered by the fabric and is a radiologically controlled area delineated by a magenta and yellow chain emplaced across the stack at the point leading into the controlled area (see Exhibit 2-1). Two movable walls (shrouds) within the building define the work area in which the only ventilated portion of the building is located. The shrouds are positioned 200 feet apart at bulkheads built into the building. These bulkheads provide connections for power, lighting, breathing air, and ventilation.
Exhibit 2-1 View Looking South in TSA-RE
No barriers were installed to keep workers away from the edge of the platform.
The scene of the accident was within the radiologically controlled area on top of the box/drum radioactive waste stack on the southeastern portion of the stacked boxes. The area had uneven footing because of the way the boxes and drums were stacked under the fabric. There was a gap approximately 30 inches wide between the edge of the stacked boxes and the adjacent metal and cinder block facility wall. The 4 foot by 4 foot by 8 foot boxes were stacked four high, making the gap about 17 feet deep (see Exhibit 2- 2). No barrier was installed to warn workers that they were within six feet of an unprotected edge of the gap.
Exhibit 2-2 Gap and Leading Edge of Stack
The platform was not intended to be a work platform without 100 percent fall protection.
A temporary platform (see Exhibit 2-3) had been installed in the area of the accident scene by the ductwork subtier contractor, Air-Con, Inc., for use in performing work on the transition piece for the exhaust air system. The platform was made of two 3/4 inch thick plywood sheets (4 feet by 8 feet) laid side by side and fastened to 2 inch by 12 inch wooden supports with screws. The outer 18 inches of the plywood sheets extended over the wooden supports (see Exhibit 2-4). The platform was intended to facilitate bolting of the transition piece and to keep parts from falling into the gap under the platform. It was not intended to be a work platform without 100 percent fall protection, and had no guardrails, toeboards, or other fall protection installed. The only lighting available in the area of the accident was ambient light from open rollup doors on the west side of the building. Illumination in the area of the platform was 2 foot- candles.
Exhibit 2-3 Temporary Platform
Exhibit 2-4 Bottom View of Platform
The project engineer was escorting a vendor inspecting a crane.
The TSA-RE is being constructed by Caddell, under subcontract to LITCO. Caddell uses subtier subcontractors to perform the actual construction work. The TC/American Monorail Company provided the cranes that carry the shrouds and the ventilation ductwork. At the time of the accident, the Project Engineer was escorting a representative (Crane Vendor) of the TC/American Monorail Company. The Crane Vendor was inspecting the adjustments to the drive wheels of the crane supporting the leading shroud (a movable seal) across the fabric-covered portion of the stack. An ironworker, who was with the group, actually performed the adjustments. Acceptance testing of the crane was to begin on the afternoon of Wednesday, February 21, 1996.
The vendor heard the project engineer fall.
The Project Engineer and Crane Vendor were on top of the waste stack in the building, starting from the west side, moving to the east, and observing the crane above them. The ironworker had gone to the other side of the shroud, and was not within view of the accident scene at the time of the accident. The Project Engineer and Crane Vendor were looking at the eastern-most drive wheel assembly of the crane. The Project Engineer passed to the east of the Crane Vendor's position to the edge of the stack and stepped onto the platform. At that point, the Crane Vendor was looking off to the side and up at the rest of the drive assembly. He heard the sound of scraping wood, looked toward the platform, and observed the Project Engineer in midair, falling into the gap between the stack and the facility wall.
The project engineer was taken to the regional medical center by helicopter and died from severe head and neck injuries.
The Crane Vendor went to the edge of the stack, and, using a flashlight to look, saw the Project Engineer lying at the bottom of the gap (see Exhibit 2-5). The first lay responder arrived at the scene at 11:25 a.m. An emergency response request was made at the same time. The ambulance arrived at 11:32 a.m. and left with the Project Engineer at 11:38 a.m., arriving at the Central Facilities Area Medical Facility at 11:49 a.m. The Project Engineer was then transported by helicopter to the Eastern Idaho Regional Medical Center in Idaho Falls, Idaho, where he died at 4:10 p.m. from severe head and neck injuries.
Last Modified: Friday, 28-Feb-97 10:09:00