GhubrahIncidentInves.. - authority for electricity regulation, oman

Report Number: R 8991
Issue: 1.1
Executive Summary
A serious incident occurred at Al Ghubrah Power and Desalination Plant, Muscat, on
9 th May 2006, which resulted in fatal injuries to two Sogex employees whilst
performing maintenance activities on the Phase 3 ‘D’ Hypochlorite storage cylinder.
Following the incident the AER requested Advantica to visit the site of the incident to
carry out a site inspection and to conduct an evaluation of the probable cause of the
incident.
The Advantica visit took place on 10 th May 2006. A verbal debriefing was conducted
at the AER offices with the Executive Director, and a document was prepared for
issue to all sites following the initial site survey and inspections, which stated that no
further work should be carried out on the Hypochlorite cylinders. The timetable for
the issue of this report was also discussed during the debriefing.
The principle cause of the incident at Al Ghubrah was a systemic failure of the
Permit to Work (PTW) system. ‘Hot’ work involving the use of electrical tools to
repair a section of the cylinder structure was allowed to take place under a
work order which referenced a ‘cold’ PTW. The ‘cold’ permit had been raised
previously to cover painting activities, and stated that no isolations, draining or
venting were required. The subsequent cylinder repair work should have been the
subject of a proper Risk Assessment which would have identified the need for the
work to be carried out under a ‘hot’ PTW with suitable gas detection and other safety
precautions, including necessary isolations and proper venting. The source of
ignition was in all probability the use of an electric drill (not fit for purpose - drill
brushes causing sparks in hazardous area, electrical connections badly made etc.)
in proximity to ‘D’ cylinder vent (not isolated and in service at the time).
There were no job-specific fire precautions (i.e. Portable fire extinguishers) in
place.
A new rigorous PTW system is required urgently for the Al Ghubrah site. Risk
Assessments should be carried out prior to all activities. The safety
department should be involved at all stages of an activity.
Scaffolding construction and inspection standards should be reviewed as soon as
possible. Although not a direct contributory factor to the incident, the poor standards
observed could be a danger to health and safety in their own right.
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