- Release of toxic/flammable materials
Texaco Refinery, Milford Haven, UK, 24 July 1994
As a consequence of flammable hydrocarbon liquid being continuously pumped into a process vessel that, due to a valve malfunction, had its outlet closed, an explosion occurred. The flare system was not designed to cope with this excursion from normal operation resulting in a failure occurred in the outlet pipe.
20 tonnes of a mixture of hydrocarbon liquid and vapour were released, ignited and subsequently exploded. This caused a major hydrocarbon fire at the flare drum outlet and a number of secondary fires.
- Inadequate maintenance of plant and instrumentation
A control valve being shut when the control system indicated it was open.
- Plant modification
Modification of the plant had been carried out without an assessment of the potential consequences.
- Control Room Design: need to address plant layout and ergonomic issues
Control panel graphics did not provide necessary process overviews. Excessive number of alarms in emergency situation reduced the effectiveness of operator response.
- Emergency Response/Spill Control
Attempts to keep the unit running when it should have been shut down