High integrity protective systems

Signoret, J-P. Dutuit, Y. Rauzy, A. 2007. High Integrity Protection Systems (TUPS) Methods and tools for efficient Safety Integrity Levels (SIL) analysis and calculations. 

I C architectures are probably at their most complex in nuclear power stations. Here, the levels of hazard and the accordingly high reliability requirements mean that diverse high-integrity protection systems are required. Furthermore, the need for extremely high-reliability removal of decay power from the reactor core postshutdown means that there has to be very high-reliability backup electricity supplies. A simplified schematic of a modem I C architecture for a nuclear power station is presented in Fig. 2.7. 

The level of overall availability for a system component calculated as 1 minus the sum of the average probability of dangerous failure on demand. SIL-1 availability of 90-99%, SIL-2 availability of 99-99.9%, SIL-3 availability of 99.9-99.99%, SIL-4 availability 99.999-99.9999%. Some common methods of achieving high SIL levels in the process industries are the employment of high integrity protective systems... 

Heat Flux the rate of heat transfer per unit area normal to the direction of heat flow. It is the total heat transmitted by radiation, conduction, and convection HIPS an acronym for High Integrity Protective System. Is a set of components, such as sensors, logic solvers, and final control elements (e.g., valves), arranged for the purpose of reverting a process to a safe state when predetermined conditions are violated. Sometimes also referred to as HIPPS, High Integrity Pressure Protective System... 

Where High Integrity protection Systems (HIPS) circuits are applied it is extremely unlikely that start-up overrides or other such circuits would be needed or allowed on the small percentage of circuits covered by the HIPS diversity. 

Broadly speaking, safety instrumentation falls into two categories safety instmmented systems (SISs) and high integrity protection systems with its subset of high integrity pressure protection systems (HIPPSs) that are used to protect specifically against overpressure. 

High Integrity Protection System International Electrotechnical Commission... 

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