The Petroleum Safety Authority Norway (PSA) has completed its investigation of the liquefied natural gas (LNG) leak in Equinor’s Hammerfest plant saying that several breaches of the regulations have been identified.
To remind, this leak occurred on June 17 during loading of a road tanker at the gas liquefaction facility located at Melkøya Island outside Hammerfest.
The authority decided on June 18 to investigate the incident.
The direct cause of the LNG escape was that a valve on the cold flaring line in the road tanker from Barents Naturgass (BNG) had been left in the open position when loading was completed at the plant’s truck filling station, PSA said.
It is estimated that about 996 kilograms, with an initial rate of 0.06 kilograms per second of LNG escaped during the incident.
The leak is judged to have had small environmental consequences and it caused no material damage or production shutdown, according to PSA.
The investigation has shown that the direct cause of the incident was the failure to close a valve during verification of the liquid level in the road tanker.
“A gas and dispersal analysis shows that the leak from the road tanker could, under marginally different circumstances, have been ignited. In that event, the road tanker driver could have suffered third-degree burns in the space of two-three seconds,” PSA said.
The PSA investigation has identified two nonconformities. These comprise deficient knowledge about and updating of operating documentation and design weaknesses in the system for overloading prevention and deficiencies in ignition source control.
Three improvement points have furthermore been identified. These comprise lack of follow-up of BNG, lack of clarity over who should evacuate in the event of a factory alarm, and the clock in the emergency response centre showed the wrong time.
PSA said that the investigation report has been sent to Equinor, which has been asked to explain how the nonconformities will be dealt with.
The company has also been asked to provide its assessment of the improvement points which have been observed.
Equinor has been given until January 24, 2019 to respond, PSA said.