Inspection Detail

Inspection: 106959216 - Tennessee Valley Authority

Inspection Information - Office: Nashville Area Office

Investigation Summary

On March 25, 2003, two employees working for the Tennessee Valley Authority (TVA) were instructed to remove a cover plate from an electrical generator at the TVA Paradise power generation plant in Drakesboro, Kentucky. The hydrogen gas had been purged from the generator and replaced with air pressurized at approximately 40 psi. The generator was pressurized with air so that the workers could perform a leak test on the system. The cover plate was 11.5 inches thick and 19 inches in diameter. It was secured to the generator by 24 bolts, which were 21.5 inches long by 0.625 inches in diameter. The two employees were informed that the cover plate needed to be removed so that a balancing weight could be removed from the shaft. It would be used as a guide to manufacture additional weights. The employees removed all 24 bolts while the system was under pressure. When the cover plate would not come loose, the employees got a pry bar and chisel to free it. They also reinstalled four of the bolts to prevent the heavy plate from falling on their feet. One of the employees used a hammer and chisel to break the cover plate loose. When the plate was loosened, the air pressure stripped the bolts from their anchor points. The plate struck one of the employees, hurling him into the air. He came to rest on a concrete floor several feet away. The employee had been killed.

Keywords: AIR PRESSURE, FRACTURE, E GI III, E GI IV, ELECTRICAL, ELECTRICAL WORK, E PTD, STRUCK BY, FLYING OBJECT, ELECTRIC GENERATOR