System Safety Analyses

Fryer, D. M., "High Pressure Safety System Analysis- A Proposed Method", Design, Inspection, and Operation of High Pressure Vessels and Piping Systems, PVP, Vol. 48. 

The assessor will need to establish which criteria have to be used in an assessment. The chosen criteria may then influence the detail safety system analysis which is carried out, since the analysis will need to provide the qualitative and quantitative results to compare against like in the criteria. 

Identification of the safety systems may also lead to savings in effort in later Steps by allowing identical parts of parallel safety channels to be subjected to a single channel generic safety system analysis and comparison with safety criteria. 

Plausibility Analysis A comparison of values for process variables that allows faults in the measurement channels of the safety system to be recognized while the process is still in its normal operating range. 

Function event trees include primarily the engineered safety features of the plant, but other systems provide necessary support functions. For example, electric power system failure amid reduce the effectiveness of the RCS heat-removal function after a transient or small UJ( A. Therefore, EP should be included among the systems that perform this safety function. Siipfiort systems such as component-cooling water and electric power do not perform safety functions directly. However, they significantly contribute to the unavailability of a system or group of systems that perform safety functions. It is necessary, therefore, to identify support systems for each frontline ssstcm and include them in the system analysis. 

LESF (Figure 3.4.5-5), exemplified for the large LOCA, is compared with SELF. Event tree headings are the refueling water storage tank (RWST) a passive component, an engineered safety system (SA-1) and four elements of the containment system. Other examples of the LESF method show human error in the event tree while the criteria for system success is usually in the tan It tree analysis. 

The analysis methods are similar for all external events probability of the external event, probability of failures, effects of failures on safety systems, and estimating the effects of failures for the workers, public and environment. 

Since safety considerations are so important in any facility design, Chapter 14 has been devoted to safety analysis and safety system design. (Volume 1, Chapter 13 discusses the need to communicate about a facility design by means of flowsheets and presents general comments and several examples of project management. )... 

The ASME code requires every pressure vessel that can be blocked in to have a relief valve to alleviate pressure build up due to thermal expan sion of trapped gases or liquids. In addition, the American Petroleum Institute Recommended Practice (API RP) 14C, Analysis, Design, Installation and Testing of Basic Surface Safety Systems on Offshore Production Platforms, recommends that relief valves be installed at vari ous locations in the production system and API RP 520, Design and Installation of Pressure Relieving Systems in Refineries, recommends various conditions for sizing relief valves. 

It should be clear that a complete FMEA approach is not practical for the evaluation of production facility safety systems. This is because (1) the cost of failure is not as great as for nuclear power plants or rockets, for which this technology has proven useful (2) production facility design projects cannot support the engineering cost and lead time associated with such analysis (3) regulatory bodies are not staffed to be able to critically analyze the output of an FMEA for errors in subjective judgment and most importantly, (4) there are similarities to the design of all production facilities that have allowed industry to develop a modified FME.A approach that can satisfy all these objections. 

Analyze Barriers and Potential Human Performance Difficulties During this phase of the analysis process, the barriers that have been breached by the accident are identified. TTiese barriers could include existing safety systems, guards, containment, etc. This analysis is called barrier analysis. The causal factors from SORTM are also applied in more detail. 

Olson, R. L., et al. IEEE Guide for General Principles of Reliability Analysis of Nuclear Power Generating Station Safety Systems, IEEE Std 352-1987. John Wiley Sons, New York, 1987. 

Rosyid, A. and Hauptmanns, U., System Analysis Safety Assessment of Hydrogen Cycle for Energetic Utilization, Proc. Int. Cong. Hydrogen Energy and Exhibition, Istanbul, 2005. 

Evaluate the risks associated with the process and its safety systems taken as a whole, including consideration of people, property, business, and the environment, that could be affected by loss events and determine whether the risks have been adequately reduced (Hazard Analysis, Risk Analysis, Source Models, Atmospheric Dispersion, Estimation of Damage Effects). 

American Petroleum Institute (API), RP 14C. Recommended Practice for Analysis. Design. Installation and Testing of Basic Surface Safety Systems for Offshore Production Platforms. Fourth Edition, API, Washington, D.C., 1986. 

Each company s management style and safety systems have strengths and weaknesses. These strengths and weakness tend to influence the types and severity of incidents that might occur. An analysis of incident investigation findings in terms of causal factors, immediate causes, contributing causes,... 

In achieving this target, all countries should seek common, science-based, international standards. FSIS should continue to ensure that equivalent inspection systems and standards for meat and poultry products exist in all countries exporting such products to the United States, especially in light of the better US safety standards expected under Hazard Analysis Critical Control Points (HACCP). FDA also should evaluate the food safety systems of other countries, with the purpose of entering into agreements with those countries having food safety systems that offer equivalent levels of public health protection to those of the United States or that can provide assurance that their products will be in compliance with FDA requirements. 

One of the most critical steps in establishing the appropriate role and settings of the individual safety systems will be the risk assessment analysis, the process in which engineers consider and analyse all possible conditions in order to select the most appropriate safety concept, which ensures safe operation under all possible circumstances and scenarios (see Section 13.4). 

Identifying the potential hazards (PHA, process hazard analysis, or HAZOP, hazard and operability analysis) during operation must be done from a wide-angle approach dangerous situations can occur due to many root-cause situations other than those specified by, for instance, ASME or PED. Based on the results of the risk assessment, the pressure equipment can be correctly designed and the most effective safety system selected. 

Under all circumstances, preference will be given to inherently safe design solutions. Safety systems should be designed to operate independent of any other functions and should operate reliably under all conditions determined by the risk analysis (including start-up, shutdown and maintenance and repair situations). 

System analysis for the assessment of the HYSOLAR program and of a utilisation program for the evaluation of safety, reliability and environmental aspects of the selected hydrogen application technologies, as well as of an educational and training program. 

Department of Energy systems analysis should specifically include safety, and it should be understood to be an overriding criterion. 

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