Description of Event:
On Tuesday July 23, 2019, at approximately 9:30 AM an Electrician (EL) was preparing to clean the unit’s rotor and set a half full can of denatured alcohol on a ledge prior to ascending a short section of steps. The Electrician lost control of the can as they attempted to set it on the ledge and the can fell approximately 30 feet, striking the plywood platform approximately 20 feet under the electrician and altering its course.
At the same time two floors below an Electrical Machinist (EM) was attempting to enter the scroll case to perform the annual wicket gate inspection and take measurements. When the EM reached for the egress ladder to enter the scroll case, the EM’s head and neck were struck by the falling can, resulting in a contusion to the head with soreness and bruising to the neck. The EM had just removed their hard hat to enter the scroll case.
A Utility Worker (UW) who was assisting the EM as the hole-watch caught the injured EM to prevent the EM from falling after being struck by the dropped object. A second Electrician (EL2) came down to the turbine area to help assist the injured EM. The EM was escorted to the control room by the UW and the EL2 where first aid and ice, were administered. The Supervisor and Care on Site were notified about the incident and the EM and the Care on Site discussed the injury.
Neither the EM nor EL was aware that their separate work areas were aligned vertically until after the incident. The EL did not identify that the work activities created a dropped object hazard potential that required mitigation.
Actions Taken:
Immediate Corrective Actions Taken
On July 23, 2019, the Supervisor contacted Care on Site. Care on Site has made frequent contact with the injured EM.
On July 25, 2019, a Safety email communication was sent to all department employees to inform them about the dropped object incident at the Powerhouse. The email included instructions to review and discuss the applicable utility procedure, Dropped Object Prevention Procedure.
On July 25, 2019, the EM installed plywood covering over the opening between the ledge and the Powerhouse wall to the right of the ladder at the location of the dropped can. On September 18, 2019, an enterprise wide Initial Communication was published in on the enterprise Intranet sharing the event with all LOBs.
On September 19, 2019, the Initial Communication was shared again with the department employees by e-mailing them directly.
Analysis
Personnel Interviews:
Results:
The employees did not recognize the dropped object hazard. The daily JSA tailboard includes a prompt to review the potential for dropped objects but it did not promote discussion regarding the expectation of work above and below the work locations because there was a solid concrete floor below the electrician. Stated another way, there was a concrete ceiling above the scroll case where the EM was working. Additionally, the opening next to the ladder was two levels above the EM and was off to the side along the wall, not vertically directly above the EM and less than a foot wide. The scroll case was not visible or in the line of sight from the Electrician’s work area.
The Electrician placed the half full can of alcohol on a ledge too narrow to support it because the ledge on the right side of the ladder at the electrician’s eye level looked to be solid like the section to the left of the ladder, but in fact there was no shelf behind the beam supporting the ledge as on the left side of the access ladder.
The platform to the right of the access ladder should have been solid like the platform to the left of the ladder.
This may have been in place since 1942 when the powerhouse was built, or it may have occurred later when the small platform was replaced, and the much smaller right-hand section was missed.
The potential for a dropped object falling from the ledge and the path continuing through the opening along the wall was not adequately considered. As determined by interviews, plant personnel did not reference the utility procedure _Dropped Object Prevention procedure to mitigate the potential for dropped objects during the annual maintenance outage at The Powerhouse. Note: Utility Procedure _Dropped Object Prevention procedure was published on May 15, 2019, communicated enterprise-wide through the company’s intranet on May 28, 2019, and to all department employees through the department’s intranet on May 23, 2019. It is also not known if this type of opening would have been considered in a review prior to this incident.
Method & Findings:
Supporting Materials:
Corrective Actions:
Sequence & Completion Dates for Actions Listed:
Lessons Learned:
Recommendations:
1. Employees should practice situational awareness in their work locations and utilize a questioning attitude about preparing for unexpected events.