Interval Reliability for Initiating and Enabling Events

System reliability modelling: The current capability and potential future developments

“…Fault trees are not a good representation of system failure logic where event sequencing is important. Dunglinson and Lamber [44], however, introduced the capability to represent initiating events and enabling events in the analysis to give a limited form of event ordering. Initiating events are those which will cause the system failure mode unless safety or control features prevent this.…”

Fire protection research for DOE facilities: FY 83 year-end report

“…not only describes the technique in detail but also presents examples of actual studies in the chemical process industry. 12 There are a number of disadvantages and de ficiencies in traditional fault-tree analysis that di graph alleviates. Since a detailed report will be published in the near future, we will present a summary of the digraph-fault-tree study.…”

“…The initiating-enabling-event-interval reliability approach is used to perform a probablistic evalua tion of the fault tree and to compute various sys tem reliability characteristics, such as the unavail ability of the water-supply system in the event of a major fire. 12 Mocho Water Supply and LLNL Monitoring System Figure 14 shows the water-supply system to LLNL. The main source of water to LLNL is the Hetch Hetchy Aqueduct, located 800 ft below ground level at the Mocho Pumping station, which is located 8 mi south of LLNL (Site A).…”

“…As described in Dunglinson et al, enabling events inactivate system mitigative or protective features but do not cause the Top Event to occur. 12 for example, an inactive alarm or burned-out light does not cause low level but does fail the operator in the event of an alarm condition. For initiating events .ve must compute their frequency of occurrence-, for enabling events, their demand unavailability when the initiating event occurs.…”

“…In addition, two separate publica tions were derived from the sen *s. Toward the end of FY 83, we initiated an 198 In the area of chemical characteristics of smoke aerosol, we started and completed hightemperature studies on the Lawrence Livermore National Laboratory (LLNL) inventory of insula-Our FY 81 and 82 year-end reports have al ready described the objectives of our efforts to create a versatile computer model that simulates fires in a forced-ventilation enclosure. 12 Here, we cover the final conclusions from an analysis of the 1982 fire-model tests, compare six fire model's predictions with the 1982 tests, and discuss the 1983 fire-model tests.…”