CUI Major Incident# 1: Fire and Explosion at the Humber Refinery

Fire and Explosion at the Humber Refinery

Date and Place of the Incident:

On April 16, 2001, failure of a Saturate Gas Plant, de-ethaniser column overhead line allowed the escape of flammable gases which subsequently exploded and caused fire at Humber Refinery, United Kingdom.

Summary of the Incident:

1. On a section of pipework on the Saturate Gas Plant (SGP), at an elbow just downstream of a water-into-gas injection point, the 6 inch diameter pipe (the overhead line carrying flammable gas under high pressure) ruptured.
2. Following the rupture a gas cloud ignited which resulted in a huge explosion and fire.
3. The force of the blast caused severe damage to the plant, to an adjacent oil refinery and a widespread damage to houses and businesses within a 1km radius of the site.

Root Cause of the Incident:

1. The cause of the incident was the corrosion and erosion of the 6 inch diameter pipe.
2. The pipe reduction in wall thickness is very significant from 7-8mm to a minimum of 0.3mm which led to the rupture as internal pressure cannot be carried anymore by the pipe.
3. The operation of a water injection point not included in the design washed away the protective coating of the pipe which permitted the attack of corrosive agents.

Financial Loss to Freedom Industries:

A total of approximately 1 million euros with costs of 300,000 euros was charged to the company for health and safety breaches.

Environmental Impact of the Incident:

About 180 tonnes of flammable liquids and gases were released to the environment during the incident.

Fatality or injury due to the Incident:

One minor on-site injury, two superficial off-site injuries were reported during the incident.

Non-Compliance of Safety Guidelines and Reliability Practices:

1. Lack of process hazard analysis for the pipe handling flammable gases.
2. Insufficient corrosion management and control program for pipeline systems.
3. Inadequate pipe inspection and monitoring program.
4. Uncertainty in emergency supervision and evacuation protocols.

Recommendations to Avoid Corrosion:

1. Perform a process hazard analysis for the pipes.
2. Implement proper visual assessment and maintenance of piping systems.
3. Set up active controls for quick detection of corrosion or any structural defect.
4. Devise proper emergency and evacuation plan and protocols.

Links to the photos/videos:

The websites below provide full access to the incident report, useful insights, and related images.

https://www.hse.gov.uk/comah/conocophillips.pdf

https://emars.jrc.ec.europa.eu/en/emars/accident/view/be38ee99-2e29-b372-1a52-b0c9e65ba3aa