While assembling a nuclear weapon in mid-September, technicians at the Pantex Plant in Texas crossed a pair of color-coded and labeled wires, an error that made it past a quality control inspection, according to a report from the Defense Nuclear Facilities Safety Board.
During the week of September 15, Consolidated Nuclear Security (CNS, which runs Pantex on behalf of the National Nuclear Security Administration, “became aware of a nuclear explosive recently assembled at Pantex in which two electrical cables were incorrectly installed,” the DNFSB report said.
Pantex is the NNSA’s primary nuclear weapon manufacturing facility. A CNS spokesperson did not respond by deadline to questions regarding the incident, including which weapon was being assembled.
Production technicians working on the weapon “inadvertently sapped the cables during the installation process,” the report said. The cables were similar but they and their connectors are color-coded and labled, the DNFSB notes.
CNS quality assurance inspection technicians failed to notice the swapped cables during a subsequent quality hold point, the report said.
The DNFSB acknowledged that CNS has made corrective actions, including briefing all production technicians on that particular weapon program on what happened and reinforcing “expectations for attention to detail,” the DNFSB said.
Going forward, weapon production managers will have to verify proper electrical connections during that step of the assembly process. All CNS quality control inspectors will receive briefings on the incident and the company’s expectations for eyes-on inspections of all cable connections during quality holds, which now will require dual verification, DNFSB said.
CNS also will require a “product verification supervisor” to be present at every quality control inspection, the report said.
