At PFP, Large Counterweight Accidently Dropped on Canyon Floor
WC Monitor
4/10/2015
At the Plutonium Finishing Plant decontamination project last month a 1,140-pound counterweight accidently fell 12 feet to the canyon floor, though no workers were in the area at the time and it is not believed to have caused damage. The crane is remotely operated using a monitor connected to cameras inside the canyon and is used to remove contaminated equipment in the canyon for size reduction and waste processing. “The work team inadvertently dislodged a counterweight that was hanging on a pencil tank strongback when the block of the crane came in contact with it,” according to a recently released March 6 DNFSB site rep report. It adds: “A critique revealed that the crane operator, spotters, and operators were focused on the hook and load, and they did not see the crane block come in contact with the counterweight. Additionally, a safety device that should have locked the counterweight in place was not operational and it appears that this condition has existed for many years.”
Work was halted for several days as contractor CH2M Hill Plateau Remediation Company conducted performance of engineering evaluations of the crane, counterweight, and canyon floor and revised work instructions, according to the DNFSB report. According to a CH2M Hill statement: “A root cause analysis currently underway will determine whether the mechanism described in the DNFSB report is appropriate to use as a ‘safety device’ and to what extent the mechanism described in the DNFSB report would have mitigated this issue.”
CHPRC emphasized that no workers were at risk because of the event. “CH2M HILL is performing work inside the Plutonium Reclamation Facility canyon using a remotely operated crane due to the hazardous environment inside the canyon; no employees were in the canyon at the time nor were they exposed to any potential for injury. This crane has operated since at least 1990, when records are readily available, without a similar incident,” the CH2M Hill statement said. “Workers responded appropriately by immediately halting work after the incident and not resuming work until an engineering evaluation was performed and additional controls were put in place, including assigning an additional worker as a ‘spotter’ from another vantage point to help the crane operator avoid a recurrence.”
