ML18065A135
| ML18065A135 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 09/28/1995 |
| From: | Smedley R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9510020241 | |
| Download: ML18065A135 (3) | |
Text
consumers Power POW ERIN&
MICHIGAN'S l'RO&RESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 September 28, 1995 U S Nuclear Regulatory Commission
- Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT RESPONSE TO INSPECTION REPORT 95008 UNRESOLVED ITEM: CONTROL OF MOBILE CRANES Inspeition Report No; 95008, dated July 27, 1995, identified an Unresolved Item (50-255/95008-01) concerning the control of mobile cranes. A response was requested concerning the causes and preventive actions for an event in
- which a mobile crane caused damage to o~erhead power lines. This letter provides the requested response.
Event Description On the night of July 2, 1995, a mobile hydra~lic crane boom cut overhead cables for the 220VAC parking lot lighting circuit. This occurred when a work
- crew was moving battery testing.equipment to the relay house.at the switchyard.
- The overhead cables, which were severed, were *1ocated on the road
. to the switchyard.. The lighting feeder breaker tripped open during the event and.no injuries or effects on plant safety systems were sustained.
This event was similar to an ea~lier event involving a mobile hydraulic.crane.
The boom of the crane came in contact with the pipe bridge between the Turbine Building and the Feedwater Purity Building.. The earlier event occurred during daylight hours while the July 2nd event occurred during evening hours.
Althou~h the consequences of both events were minor, the potential for personnel injury or loss of power to plant equipment elevated their significance.
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Causes Three causes were identified during the event investigation.
The first was inadequate installation of the overhead cables. The National Electrical Code requires cables to be a minimum of 18 feet above a road.
It is believed that the severed cables were sagging to a height less than 14 feet because of a leaning pole which was not properly supported by a guy wire. This is a deduction based on the fact that the crane boom passed under the 14-ft high pipe bridge to the Feedwater Purity Building en route to the switchyard.
The boom was not raised after the pipe bridge was cleared.
The second cause of the event was human error. Crane operators are required by the Consumers Power Company Accident Prevention Manual to assure the path is clear in the direction of travel when operating a mobi.le crane. This was*
not done.
The infrequent travel to the switchy*rd and previous trouble free operation of the mobile crane led the operator to a ~alse sense of security.
The third cause was inadequate training for the.mobile crane operators.
The training did not provide for checking travel routes clear unless th~ crane would be carrying a load.
In both events, there was no load.
Actions Taken to Prevent Recurrence 2
Immediately after the overhead wire was severed, the Plant General Manager issued a letter to communicate his expectations to all departments having mobile crane operators.
The letter discouraged crane operations.at night and required discussion of equipment interferences, travel paths, and overhead clearances in pre-job briefings. It also required the use of dedicated spotters for all crane operations to provide verification to the operator that the path is clear. The letter was discussed with all mobile crane operators.
A permanent guy wire was installed on the leaning pole which had permitted the cables to sag. Additionally, site inspections were performed to verify that the height of overhead wiring was in compliance with*the National Electrical Code. All overhead wires, except one, have* been verified-or repaired.* That one exception will be corrected by a separate utility. Also, a site map was developed detailing all overhead wires and overhead obstructions. This map was forwarded to the Training Department for use in site specific mobile crane operator training.
The lesson plans for site specific mobile crane operator training are being revised to include the use of spotters and the overhead obstruction map.
Personnel operating mobile cranes will be required to attend this training as part of their qualification~
SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
Richard W Smedley Manager, Licensing CC Administrator, Region JII, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades 3