Worst Credible Process Fire: Experiences from the Norwegian Petroleum Industry

Sammanfattning: The term Worst Credible Process Fire (WCPF) was introduced to the Norwegian Petroleum Industry as a complement to the probabilistic approach to define design loads for offshore facilities. Currently there are mainly two documents about the WCPF being the SINTEF report (2017) and the definition in NORSOK S-001 (2018). The WCPF concept have only been used within the industry for a few years and combined with the limited literature there might be some challenges that need to be considered. To investigate this, interviews were held with safety experts from various actors within the industry. With these interviews it was possible to address what the challenges are and if the perspectives vary within the industry. Similar concepts such as worst-case scenarios, maximum credible scenarios and worst maximum credible scenarios were also studied as a complement to the interview study. The thesis found that some of the main challenges were subjectivity in scenario selection, lack of probability perspective and limited documentation for heat loads, temperatures and fire duration. The thesis concluded that the view of the WCPF was not unified as the PSA is asking what is done and the industry how it is done. New companies did not seem to be unfairly affected by the limited literature in comparison to older companies. There were also some disagreements within the industry on how to approach the analysis. Variations within the industry could be approached in three separate ways, being transparency, standard methods and further clarification of the WCPF. Currently the literature surrounding WCPF could be considered enough but could be improved with additional clarifications. Lastly, the way barriers are credited in the WCPF could be improved and more justifiable with a higher focus on barrier management.