| Abstract |
A methodology has been developed for completing a plant risk assessment for geothermal fluid collection and disposal systems (FCDS) with a view to applying the principles of risk based inspection to the plant asset management practices. The joint Australian StandarUNew Zealand Standard, AS/NZS 3788 Pressure Equipment - In-Service Inspection, is the base resource document for the work. The plant risk assessment assigns each individual component within the plant a risk rating, which allows plant inspection and maintenance to be targeted and prioritised, both during operation and at scheduled shut downs. The plant risk assessment is developed by quantifying the likelihood of corrosion and metallurgical damage, which has already, or is likely, to occur. Secondly the consequence of this damage occumng is quantified in terms of commercial, methodology has been developed for combining these likelihood and consequence ratings to give an overall risk rating for each component in the plant. This Phase 1 assessment of a three phase Risk Based Inspection programme provides a rigorous analysis on which to base an initial prediction of the remaining life of the individual components being assessed. The immediate advantages are an ability to predict which items require detailed condition inspection, which are likely to require maintenance or replacement in a given timescale and which are suitable for immediate life extension beyond their design life. This has obvious cost benefit implications for the optimised and prolonged operation of the plant. |