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Audit of Statoil Mongstad – electrical installations and follow-up of the cracker incident

During the period 23-25 March 2010, the Petroleum Safety Authority Norway (PSA) conducted an audit of Statoil Mongstad, connected with electrical installations and follow-up of the cracker incident. One regulatory non-conformity was identified during the audit.

This audit activity is related to the PSA’s main priority for 2010, “Technical and operational barriers”.

Read more about the PSA’s main priorities for 2010.

Within the area of electrical installations, emphasis was put on the Mongstad transformer station and electrical installations connected to Energiverk Mongstad.

In connection with the audit, a joint inspection was conducted with the Directorate for Civil Protection and Emergency Planning at the Mongstad transformer station.

The goal of the audit was to gather information on how the company works on follow-up of electrical installations and measures following the cracker incident, and measure this against regulatory requirements.

The audit was conducted with positive facilitation by Statoil, and the participants made a good technical impression.

The audit identified one regulatory non-conformity, which is related to updating documentation. The report also contains five observations where there is potential for improvement.

The PSA’s observations are generally placed into one of two categories:

The assessments have been made pursuant to “Temporary regulations relating to safety and working environment for certain petroleum facilities on land and associated pipeline systems” (Temporary regulations).


Documentation: Deficient documentation.
We observed several examples of documentation that had not been updated or was deficient:
a) In connection with the review of Mongstad’s electrical management coordination contracts, we were presented with different versions.
b) Different versions of electrical one line diagrams were found in kiosks.
c) Mongstad’s explosion protection document was not updated concerning the responsible person.

Improvement items

Rock filter in oil pits: Foreign objects in the rock filter in connection with transformer oil pits.
In connection with the inspection at the Mongstad transformer station, we observed that sand and moss had gathered in the rock filter in connection with transformer oil pits.

We were informed that mud, leaves and a leak were found in the oil pit for the transformer that has been out for maintenance.

Locking high voltage rooms: Secure by locking so that unauthorised persons do not have access to high voltage installations.
In connection with reviewing synergy reports, several examples were found of report of unlocked doors leading to high voltage installations.

Labelling and signage: Deficient labelling and signage at Energiverk Mongstad.
In connection with the verification inspection at Energiverk Mongstad, several examples of deficient labelling and signage were observed.
a) labelling doors leading to rooms
b) labelling panel doors
c) labelling battery bank

Mechanical cable protection: Deficient mechanical cable protection at Energiverk Mongstad.
We observed several examples of deficient mechanical protection of cables running through the floor in the switchgear room.

Protective equipment in the switchgear room: The high voltage room at Energiverk Mongstad was not equipped with a rescue pole.
In connection with planning work, an assessment shall be made of which protective equipment to be used.

In connection with the verification inspection at Energiverk Mongstad, we observed that the high voltage room was not equipped with a rescue pole. The rescue pole can be an important consequence-reducing measure in connection with work in the SWG room.

Other comments

Measures following the cracker incident on 23 August 2008
All planned reviews and verifications have been conducted. Some of the reviews cover the whole refinery, not just the cracker, for example aging of equipment and components and studies to find common components for the ESD and control systems. Hazop has been performed for the cracker, but a plan has yet to be made for future work.

Damage to door at Mongstad transformer station
We observed that the door to the Mongstad transformer station was damaged and could not be locked. We were informed that a work order had been issued for the work, and that the door would be repaired in week 12.

Need for H2 detection in ventilation discharge from battery room at Energiverk Mongstad
We noted that there was an incident relating to boost charging which caused a hydrogen build-up from the battery bank. Based on this, an assessment should be made of the need for H2 detection in the ventilation discharge.