High Integrity Pressure Protection Systems

Complete the conceptual design requirements for a SIL 3 High Integrity Pressure Protection System (HIPPS) required to protect a main separator fed from multiple well heads from over pressuring. A simplified P ID for the installation is shown in Figure 13-22. 

Risk assessments for high integrity pressure protection system by using layer of protection analysis... 

To estimate the rate of DU-failures is a challenging task. First, DU-failures are rare events since the SIS is designed for high reliability. Second, there may be only a few components of the same type for observation. Whereas an installation may have more than 100 fire detectors, the number of certain valves, for example high integrity pressure protection system (HIPPS) valves, may be limited to one or two. 

High-pressure trip High integrity pressure protection system—an active and preventive protection layer. 

HIPPS High integrity pressure protection system... 

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... 

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. 

A High Integrity Pressure Protection System (HIPPS) is a particular type of SIS that prevents overpressure scenarios. It shuts off the source of high pressure before the safe upper limit is reached. It is a barrier between high- and low-... 

High Integrity Pressure Protection Systems (HIPPS),... 

The primary cooling ciicuit in a PWR is a high-integrity, pressure-resistant system that will contain any fission products released from the fuel in an accident until the internal pressure exceeds the values that would actuate the pressure relief devices. A simple, conqiact primary system will be easier to qualify and inspect and to protect from seismic events and external hazards. The RPV penetrations should be as few as possible and of small diameter. All primary system openings would be kept sealed for die duration of autonomous operation. 

A technical superintendent at TMI-2 who arrived on the plant at 03 45, subsequently said I had the perception that we were in a very unusual situation, since I had never seen the pressurizer level increase and stay at a high value and, at the same time, the pressure staying low. They [the pressure and the level] had always behaved in the same way . As a consequence of the described evaluation errors the primary circuit continued to lose water for hours and in addition the automatic core cooling system, correctly activated, could not perform its function of fuel integrity protection. It is now known that if the block valve had been closed after one and half or two hours or if the operation of the HPI only had not been arrested, even without the closure of the valve, the Three Mile Island accident would have been no more than a modest nuisance of operation. For completeness of information it has to be added that the possibility of an accident of the type of TMI-2 had been foreseen by some experts. If these foresights had been confirmed by in-depth theoretical studies and possibly by experimental tests, their results, duly made known to interested people, would have enabled the TMI-2 operators to correctly diagnose the fault and react correctly. 

For batteries under overpressure and/or for high power, a pressure vent is integrated into the cell case. Additionally melting fuses or back-setting fuses — so-called thermo switches - are used. All this protects the system against overheating and uncontrolled pressure rise in case of a short. 

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