A federal official briefed on the matter said the issue was a drug test. The company had earlier said that Abdulazeez had failed a background check.
Abdulazeez underwent general training on company procedures, but his access was limited during his brief employment, Schneider said.
“He worked in an administrative building,” Schneider said. “He was never allowed in the protected area of the plant near the reactor.”
http://www.washingtontimes.com/news/2015/jul/17/relative-ohio-native-among-injured-in-chattanooga-/
It seems more likely that he failed the check for the security clearance needed to gain access to the restricted areas at the plant. It’s CYA time for DHS.