The Petroleum Safety Authority Norway (PSA) has completed its investigation of an incident with a fire in the air intake of turbine 4 at Hammerfest LNG on 28 September 2020. Serious breaches of the regulations have been identified, and an order has been issued.
Process safety Structural safety Emergency preparedness
When the fire broke out, the Equinor-operated plant was being run up after a shutdown. The turbine had been shut down owing to a fault in an oil filter.
Actual and potential consequences
The fire caused material damage to the GTG4 air intake and filter housing and consequential damage from extinguishing work to electrical, instrumentation and mechanical equipment. Hammerfest LNG has been shut down since the fire and is due to resume operation on 1 October 2021.
Three vessels with firewater monitors helped the extinguishing work. Without this assistance, the fire would have burnt for longer since the plant’s own firewater monitors do not cover the turbine air intake.
The probability that the fire might have spread to neighbouring areas is considered to be small, but it could have caused more extensive damage to the filter and generator housings.
No personal injuries have been reported as a consequence of the fire.
Direct and underlying causes
Technical fire tests and simulation of temperature development in the turbine’s filter housing support the likelihood that the fire broke out because pre-filters in the air intake auto-ignited. The tests indicate that biomass buildups (primarily insects) in the pre-filters may have lowered their auto-ignition temperature.
The control valve for hot-oil supply to the air intake’s anti-icing panels had been opened manually to dissipate excess heat in the hot-oil circuit. This caused the temperature in the filter housing to rise sufficiently to auto-ignite the pre-filters.
The investigation has identified several elements which were or could have been significant for the fire breaking out. This applies to
- manual control of hot-oil supply to the anti-icing panel
- follow-up of earlier incidents with melting of filter cassettes and practice with manual operation of the control valve
- filter replacement
Nonconformities and improvement points
The investigation has identified five nonconformities related to
- management and control
- manning in the organisation
- risk analyses
- filter maintenance
- overview of external emergency response resources.
Three improvement points have also been identified, related to:
- overview of performance requirements in the emergency preparedness plan
- follow-up of leaks from anti-icing panels.
The PSA’s investigation has identified serious breaches of the regulations, and it has therefore issued the following orders.
Pursuant to section 69 of the framework regulations on administrative decisions, Equinor Hammerfest LNG is ordered to do the following.
Identify, implement and follow up measures to ensure compliance with the management system, including ensuring that knowledge and necessary information available within the company are communicated in a systematic and appropriate manner to operations personnel in order to ensure safe operation. See section 21 of the management regulations on follow-up, section 40, litera c of the technical and operational regulations on start-up and operation of onshore facilities, and section 45, paragraph 2 of the technical and operational regulations on procedures. See section 10.1.1 of the report.
Demonstrate by submitting short- and long-term plans for operation of the plant that activities at Hammerfest LNG have adequate manning and competence to deal with all operating conditions. See section 14 of the management regulations on manning and competence. See section 10.1.2. of the report.
Prepare a binding and timetabled plan for complying with the orders above.
The deadline for compliance with the orders under bullet points 1 and 2 is the start-up date for the plant at the latest.
The plan for complying with the orders must be presented to us by 1 June 2021. We must be informed when the orders have been complied with.