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Lessons Learned Issued in 2001
Dry Chemical Fire System Inadvertently Discharged
Date: August 2, 2001
Identifier: 2001-RL-HNF-0026
Lessons Learned Statement:
Maintenance personnel must have adequate current information regarding the system and components on which they are working to safely and successfully accomplish their maintenance tasks. Previous lessons learned information can help prevent repeat incidents.
All information regarding equipment and systems must be turned over when a new organization takes over maintenance duties and responsibilities for equipment.
Discussion of Activities:
Fire Systems Maintenance personnel, accompanied by facility operations personnel, were performing a 6-month preventive maintenance action on a dry chemical system providing fire suppression for a TRU glovebox enclosure. The system control head was locked and pinned in the "safe" or non-operational mode. A CO2 cartridge creates the operative force to open the discharge valve and expel the main dry chemical. When the cartridge was removed about half a turn, twenty-five pounds of the dry chemical discharged into the glovebox. The normal operating mechanism did not operate and no alarms were transmitted.
Analysis:
Investigators determined that a small spacer washer was missing from the control head where the CO2 cartridge is seated, allowing the cartridge to be threaded in far enough to be pierced by the mechanism firing pin. When maintenance personnel removed the cartridge, its contents discharged and actuated the main dry chemical container valve.
The Fire Systems Maintenance organization had no information regarding the possibility of an accidental discharge caused by the missing spacer washer. When Fire Systems Maintenance took over the maintenance responsibilities for this system, they were provided only the manufacturer's original installation and maintenance manuals. Those documents did not include any manufacturer's bulletins nor any lessons learned information regarding the possibility of accidental discharge from a missing spacer washer. That information had been made available to "licensed distributors" by the manufacturer but was not forwarded automatically to "end users".
Recommended actions:
Fire Systems Maintenance has revised its preventive maintenance procedure for all systems of the same type on site to include steps to remove the control head from the dry-chemical at the beginning of the work process and to verify proper placement of the spacer washer before reinstalling the CO2 cartridge.
Owner organizations that have these systems in their facilities will be made aware of the conditions that could lead to failure as well as these corrective measures.
The information regarding this incident, the cause, and corrective actions being taken will be presented at the next Hanford Fire Protection Forum meeting to ensure that all of the site Fire Protection Engineers and other appropriate persons are aware of this situation.
Fire Systems Maintenance, through the Office of the Hanford Fire Marshal, has requested the manufacturer to provide all bulletins and supplemental information regarding this equipment that is was not in the original installation and maintenance manuals. They have queried other manufacturers of similar equipment on Site, searched websites, and reviewed manuals to see if similar problems may exist. This system appears to be the only one with such an anomaly that could cause an inadvertent discharge.
Estimated Savings/Cost Avoidance: N/A
Priority Descriptor: BLUE/Information
Work / Function: Fire Protection; Maintenance - Safety Systems
Hanford-Defined Category: N/A
Hazard(s): Personal Exposure-Hazardous Material; Pressurized Systems
ISM Core Function(s): Analyze Hazards
Originator: Fluor Hanford, Inc. Submitted by Bart Gibson, 509-376-9061
Contact: Project Hanford Lessons Learned Coordinator; (509) 373-7664; FAX 376-6112; e-mail: PHMC_Lessons_Learned@rl.gov
Authorized Derivative Classifier: Not required
Reviewing Official: John Bickford
Keywords: Dry chemical, fire system, maintenance
References:Occurrence report RL--PHMC-WRAP-2001-0002
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