An example of converting a static PSA into a living PSA for an older operating reactor

A static PSA has been constructed with the Risk Spectrum PSA (RSPSA) computer code for the 20 year old Prototype Fast Reactor (PFR) at Dounreay, in Scotland. This study was carried out as part of a safety review for this plant and the results are briefly presented. This static PSA has subsequently been converted into a living PSA (LPSA) to demonstrate certain LPSA applications. The methodology for converting the static PSA to a LPSA is described. The LPSA has been used to evaluate test interval (TI) optimisation and risk based allowed outage times (AOT). The results of these studies are presented with the test interval optimisation studies, showing that different testing schedules can achieve a reduction in overall risk. There is also scope for economic benefit in using such a living PSA approach. (author)