Two contractors working near a 6.9kV electrical bus were injured in an arc flash incident on March 16th at the Tennessee Valley Authority’s Sequoyah Nuclear Plant near Soddy-Daisy, TN, northeast of Chattanooga.
According to an event notification report from the U.S. Nuclear Regulatory Commission (NRC) posted Monday, the two contractors were transported to a medical facility for treatment. “The cause of the arc flash is not understood at this time, an accident investigation has been initiated by TVA,” the report said.
The two injured contractors sustained first and second-degree burns. Both are employees of Day & Zimmerman, an engineering, construction and security firm based in Philadelphia. TVA told television station WRCB that it has suspended similar work activities until the cause is understood.
Neither of the workers were shocked or contaminated by radiation in the incident. The TVA’s two nuclear reactors at the site, Sequoyah Unit 1 and Unit 2, remain at 100 percent power, the NRC said.
When an arc flash happens, it does so without warning and is lightning quick. The result of this violent event is usually destruction of the equipment involved, fire, and severe injury or death to any nearby people. Proper safety and protection measures must be taken to limit the damage from an arc flash which include conducting an arc flash study, short circuit study, and NFPA 70E electrical safety training.