Following the incidents major public and political concern was expressed to the Competent Authority and the Competent Authority was concerned due to the frequency and pattern of the serious incidents, their major accident potential and the apparently deteriorating performance of the Complex.
It was apparent that the main concerns centred on health and safety issues so it was agreed at an early stage with the Scottish Environment Protection Agency (SEPA) that the HSE would take the lead in the investigations with assistance from SEPA as necessary. The FCCU fire in particular was a reportable major accident under the COMAH Regulations and a major accident investigation was therefore required.
The HSE Board called for a "Level 1" Major Accident Investigation to be carried out by Land Division, Hazardous Installations Directorate (HID) in accordance with the then corporate major accident investigation procedures.
A series of incident specific investigations for the power distribution failure, MP steam main rupture and FCCU fire in order to examine the direct and underlying causes were accompanied by a series of further investigations into related issues from the incidents such as the emergency response, the environmental impact and the response to the presence of asbestos during the FCCU fire.
Evidence of the extent of the Competent Authority’s concern is provided by the scale of investigations carried out which involved significant HSE Inspector, HSE Specialist Inspector and Health and Safety Laboratory (HSL) resource as well as involvement from SEPA Inspectors. Investigations continued until February 2001, when the "Summary of Findings and Recommendations Report" was sent to BP and the prosecution report was sent to the Procurator Fiscal (the public prosecutor in Scotland).
Consideration was given by the Competent Authority to carrying out a full-scale audit of the entire Complex of the type the HSE had carried out at BNFL Sellafield and UKAEA Dounreay. The Complex Director set up a BP Task Force to carry out an extensive safety and environmental audit of the Complex led by a senior executive from outside the Complex. The setting up of such a major BP Task Force, which involved independent overview from a respected expert, allied with the thoroughness and open sharing of findings with the Competent Authority eliminated the need for a Competent Authority audit running alongside the major accident investigation. The Competent Authority received regular electronic updates of the current status of audits, actions and tracking of progress from BP. BP reported to the HSE daily any issues that were identified during the 6 week period over which the units in the Complex were brought back into operation.