The United Kingdom Onshore Pipeline Operators Association (UKOPA) was formed by UK pipeline operators to provide a common forum for representing pipeline operators interests in the safe management of pipelines. This includes ensuring that UK pipeline codes include best practice, and that there is a common view in terms of compliance with these codes.
Quantitative risk assessment (QRA) is used by operators in the UK to determine if individual and societal risk levels at new developments adjacent to existing pipelines are as low as reasonably practicable (ALARP). In 2008 the UKOPA Risk Assessment Working Group developed codified advice on the use of QRA applied to land use planning assessments, which was published by the Institution of Gas Engineers & Managers (IGEM) and the British Standards Institute (BSI). This advice was designed to ensure a standard and consistent approach, and reduce the potential for disagreement between stakeholders on the acceptability of proposed developments.
Since publication of IGEM/TD/2 and PD8010-3 in 2008, feedback from users of the guidance together with new research work and additional discussions with the UK safety regulator, the Health & Safety Executive (HSE), have been undertaken and the codified advice has been revised and reissued in June 2013.
This paper describes the revisions to the guidance given in these codes in relation to:
• Clarification on application
• Update of physical risk mitigation measures (slabbing and depth of cover)
• Update of HSE approach to Land Use Planning
• Update of failure frequency data:
○ Weibull damage distributions for external interference
○ Generic failure frequency curve for external interference
○ Prediction of failure frequency due to landsliding
The revised codes, and their content, are considered to represent the current UK best practice in pipeline QRA.