Hazop analysis

The cost of performing the hazard identification step depends on the size of the problem and the specific techniques used. Techniques such as brainstorming, what-if analyses, or checklists tend to be less expensive than other more structured methods. Hazard and operability (HAZOP) analyses and failure modes and effects analyses (FMEAs) involve many people and tend to be more expensive. But, you can have greater confidence in the exhaustiveness of HAZOP and FMEA techniques—their rigorous approach helps ensure completeness. However, no technique can guarantee that all hazards or potential accidents have been identified. Figure 8 is an example of the hazards identified in a HAZOP study. Hazard identification can require from 10% to 25% of the total effort in a QRA study. 

Table 14 Typical Questions in P2 Assessment Analogous to HAZOP Analyses...

Realization of systematic safety reviews at the different stages of planning and procurement including HAZOP analyses (cf. Sect. 9.1.2.3). 

The GoM has 5000—6000 platforms, many of them small and in shallow water. It is simply not economically feasible to write a safety case for each platform. Arnold (2010) uses the example of the response to a proposed requirement from the MMS to carry out a Failure Modes and Effects Analysis (FMEA) on each facility. Instead of doing this, a generic response based on FMEA and HAZOP analyses of 13 representative facilities was conducted. The use of a generic study was justified because the process equipment and instrumentation function in the same manner regardless of the specific design of the facility. 

Hazards and Operability (HAZOP) analysis is an accident detection and prevention technique used primarily by the chemical process industry (CPI) (Lees, 1980). Even though the CPI operates in a different regulatory environment from the commercial nuclear power industry, the goals of risk reduction while maintaining productivity are similar. 

I iach study node is examined for potentially hazardous process deviations. First, i he design inte-iit of the equipment and the process parameters is determined and recorded. Process de iatiuns from the design are determined by associating guide words with important process parameters. (iiiidt words for a HAZOP analysis are shown in Table 3.3.4--1 process parameters and dt. i itions are shown in 1 able, T3.4-2. 

A HAZOP study is a systematic, tabular document of process deviations. The study gives the noimal operating conditions and analysis boundary conditions for each item and lists action items for further evaluation. Tables 3.34-3 and 3.3.4-4 are examples of HAZOP analysis of the Dock 8 HF Supply System and the Cooling Tower Chlorination System, respectively (for a more complete study see DOE, 1973). These example show the format for HAZOP tables. A typical HAZOP study... 

New systems or processes may also need to be qualified from an operational safety perspective. This is particularly relevant in the case of chemical synthesis involving exothermic reactions. Critical safety aspects are usually identified using hazard operability or HAZOP assessments and studies. For example, a HAZOP analysis of an exothermic reaction vessel would involve consideration of the consequence of failure of the motors for mixers or circulation pumps for cooling water. Thus, the qualification of such a system would involve checks and assessment to ensure that the system/process can be operated safely and that pressure relief valves or other emergency measures are adequate and functional. 

Venkatasubramanian, V.. and Vaidhyanathan, R., A knowledge-based framework for automating HAZOP analysis, AIChE J. 40(3), 496 (1994). 

See also Hazard acceptance Hazard assessment Hazard identification entries limitations of, 13 153-154 probability, 13 166-170 purpose of, 13 152 scenario identification, 13 165 source modeling and consequence modeling, 13 165-166 sustainable development and, 24 183-188 techniques for, 13 152-154 Hazard and operability (HAZOP) analysis, 13 154, 157-159 guide words for, 13 158t sample, 13 159... 

The HAZOP analysis technique uses a systematic process to (1) identify possible deviations from normal operations and (2) ensure that safeguards are in place to help prevent accidents. The HAZOP uses special adjectives (such as speed, flow, pressure, etc. see table 5.5) combined with process conditions (such as more, less, no, etc. see table 5.6) to systematically consider all credible deviations from normal conditions. The adjectives, called guide words, are a unique feature of HAZOP analysis. 

Table 5.5. Common HAZOP analysis process parameters... 

Checklists may also be used to supplement other tools for example, checklists on human factors may be used in conjunction with logic trees. Similarly, checklists may be used in combination with structured brainstorming tools such as What If/Checklist and Hazard and Operability (HAZOP) Analysis.(P It is also a good practice to apply a tool like the 5-Whys to the root causes identified from the checklist to verify whether they are truly root causes. 

Proof of concept of the laboratory process HAZOP analysis Validation of analytical methods ON I ... 

The process control scheme for the absorption column is presented in Figure 9.6. It was designed from the recommendations presented in the HAZOP analysis, the results of which are reported in Section 9.8. It features ratio control on the make-up water stream. The signals from flow transmitters on this line and on the gas input line are fed to the ratio controller, whereby the make-up water stream is adjusted. 

Note if a HAZOP analysis is used, about 89 hours would be needed). 

If a HAZOP analysis is used the estimated cost is approximately 18,151 a 57% increase in costs )... 

An equipment-based methodology, e.g., HazOp Analysis, begins the identification of hazards with the postulation of specific process variables... 

There are usually surprises when new processes are first tried. In view of the particular sensitivity of the chemical agent disposal program, the committee emphasizes the need for a hazardous operations (HAZOP) analysis for any new process (see Chapter 4). A HAZOP analysis by suitably trained people, and with input from operating people, could be particularly useful it might identify problems and at the same time warn the operating people about what to expect. 

The cooperative team has also established a common FMEA (Failure Mode Evaluation and Analysis) system using the power converter FMEA from Caterpillar as a template, and expanding this approach to define a preliminary HazOps analysis to be conducted in the future. 

At this phase no technical hurdles are anticipated. Future actions include conducting a safety design review (HazOps analysis), establishing an activity-based target date for a critical design review, and generating a system level functional specification document which will help define the research boundaries for this project. 

Prior to start up and commissioning it is usefiil to go through possible sequences of effects and operations - similar to Hazop analysis, to determine situations and conditions that should be avoided to reduce the potential for fouling of heat exchangers. 

Hazard operability (HAZOP) analysis. The process is analyzed purely from an equipment versus safety angle. Every single operation involved in the process is discussed by the cross functional team (CFT) for potential safety issues that could arise out of operations and any unexpected equipment failure. If any such condition is identified, the GET identifies a remedy and implements it before scale-up. 

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