A problem with a “1960s-vintage” elevator in the Beta-2 facility at the Y-12 National Security Complex spawned a series of events in late April that created an oily mess and provided yet another example of the challenges resulting from the plant’s aged infrastructure.
According to a newly released report by staff of the Defense Nuclear Facilities Safety Board, hydraulic elevator equipment in Beta-2 (Building 9204-2) overheated on April 25 and caused a sprinkler head to activate. The facility is known to conduct work with lithium for nuclear weapons parts.
The plant’s Fire Department responded to the scene and, while noting an “oily haze” in the air, did not find any evidence of a fire. The sprinkler had activated in a first-floor elevator equipment room.
“The Fire Department verified there was no fire and immediately closed the water supply valve for the sprinkler,” the report stated.
With the water off, there had to be a “limiting condition of operation” put into play to compensate for the loss of a sprinkler.
The report said the exact cause of the sprinkler activation had not been determined, but the elevator technician “believes that the hydraulic motor continued to run after the elevator was last operated.”
That, in turn, heated the hydraulic oil in the reservoir above the motor and “caused the ambient room temperature to rise.”
The sprinkler head was designed to activate at 165 degrees Fahrenheit.
When the sprinkler activated, the water “interacted” with the heated oil in the elevator reservoir, thus causing the oily haze and creating a spill that covered about 2,500 square feet of the building’s first floor.
The elevator codes for the old elevator did not require the timed shut-off function of modern elevators, according to the report.
Consolidated Nuclear Security, the Y-12 contractor, noted that the elevator was due for replacement “dependent on funding.” The contractor also directed an “extent-of-condition review” to determine if other elevator systems at the plant had similar vulnerabilities.
In response to questions, Ellen Boatner, a spokeswoman at Y-12, said the oil and water cleanup at Beta-2 had been completed following the incident.
The elevator, however, is still shut down “pending repair,” she said.
Asked what had been done to replace the elevator, Boatner responded, “Y-12 relies upon an established Plant Health Committee process to evaluate safety and mission risks across the site. Using this process, a detailed engineering analysis of large freight elevators that rely on a direct buried hydraulic cylinder was performed.”
“This elevator,” she said, “will remain as a high priority for the site moving forward and will be included in future budget submittals until it is replaced.”
