The recent changes in the UK North Sea Regulatory environment have seen the introduction of goal setting regulations, based on an explicit demonstration of safety. Further regulations require demonstrations of structural integrity as a means of aiding the safety demonstration. This move away from universally agreed prescriptions has encouraged risk based approaches to hazard assessment and control. This has required investigations into safety levels and rapid development of tools and models that previously only existed in the research environment for this purpose. With any method or technique for safety/failure assessment a common stumbling block is the meaning and setting of target safety levels. Most modem standards are calibrated in some way and much discussion is had on the interaction of this calibration with target safety levels, especially for existing structures. The paper will discuss and report on work recently undertaken in HSE on the above areas.
The regulatory requirements on which the design and assessment of offshore installations on the UK Continental Shelf (UKCS) are based have undergone major changes in the years following the Piper Alpha disaster (REF 1). An update on the current situation is described by Jones (REF 2), and the full effect on matters concerning structural integrity are now well advanced (REF 3). The changes affect both the design and reassessment of installations at a number of different levels. Certification is to be replaced by independent verification, and safety criticality is the new focus. At the highest level the new legislation is goal setting, and prescriptive requirements have been deleted in favour of allowing responsible parties to adopt broader technical and innovative solutions with which to meet the overall goal of demonstrating that the risks from a major accident are reduced to a level that is as low as reasonably practicable - the ‘ALARP’ principle.