According to a recently released March 21 memo by staff of the Defense Nuclear Facilities Safety Board, an 8-foot-section of the concrete ceiling at Y-12’s Beta-2 facility fell into an area that had previously been roped off because of studies — dating back to 2009 — that showed serious “delamination” and potential hazards. But chunks of concrete from the slab then bounded into a “frequently used” walkway and an adjacent welding station, the report stated. Some of the chunks were greater than a foot in diameter and 2 inches thick.
“No personnel were struck by the concrete, but workers had used the welding station earlier that day,” the safety board memo stated.
This “near miss” incident seems to typify some of the concerns raised over the past several years about the deteriorating conditions at some of Y-12’s aged facilities. The section of the DNFSB report was titled, “Aging Infrastructure.”
According to the report, a previous inspection at Beta-2 had determined that extensive corrosion was caused by Kathene (aqueous lithium chloride) from a dehumidification unit on the floor above the area in question.”
B&W Y-12, the government’s managing contractor at Y-12, confirmed that pieces of falling concrete actually struck a portable welding exhaust unit (which received minor damage). The contractor, however, emphasized that no one was hurt in the incident.
“Personnel in a nearby area heard the noise, discovered the problem, and immediately notified the shift manager,” the federal contractor stated. “Personnel responded as trained to the situation, and general access to the surrounding area has been removed.”
Considering how close the falling concrete came to a used area of the facility, I asked B&W Y-12 Vice President Bill Reis if additional precautions should have been taken — considering the earlier studies of degradation in the area.
“Appropriation precautions were taken to control access to degraded areas and to require proper (personal protection equipment) when entering areas under access control,” Reis said in an email response to questions.
Asked about the contractor’s corrective actions, he said, “Removed general access to areas surrounding recent delamination, inspected other identified degraded areas across the site, controlled access below degraded areas, prioritized repairs.”
Reis said the area where the concrete rebounded into was “routinely” used, but not heavily used (as I said in my question). The report by the safety board staff said the walkway area was frequently used.
“We took precautions as described above to keep people from getting hurt — and no one was hurt,” he said.
A new feature on Atomic City Underground allows readers to sign up for email updates and receive a notice each time new information is posted on the news blog. Just put your email address in the box on the lower right of the blog’s front page and follow instructions. Thanks to all loyal readers.