Accidents minimization

Perhaps the key to determining die consequences of an accident is die study of accident minimization/prevention. Tliis topic receives extensive treatment in Section 17.2. The estimation (not calculation) of consequences is treated in Section 17.3, which is followed by evacuation procedures (Section... 

Pharmaceutical powder aerosols have more stringent requirements placed upon the formulation regarding moisture, particle size, and the valve. For metered-dose inhalers, the dispensed product must be deflvered as a spray having a relatively small (3—6 -lm) particle size so that the particles can be deposited at the proper site in the respiratory system. On the other hand, topical powders must be formulated to minimize the number of particles in the 3—6-p.m range because of the adverse effects on the body if these materials are accidently inhaled. 

The result of the ETA is a Hst of combiaations of equipment and human failures that ate sufficient to result ia the accident (71). These combiaations of failures are known as minimal cut sets. Each minimal cut set is the smallest set of equipment and human failures that are sufficient to cause the accident if all the failures ia that minimal set exist simultaneously. Thus a minimal cut set is logically equivalent to the undesired accident stated ia terms of equipment failures and human errors. 

Loss of containment due to mechanical failure or misoperation is a major cause of chemical process accidents. The design or storage systems should be based on minimizing the hkelihood of loss of containment, with the accompanying release of hazardous materials, and on limiting the amount or the release. An effective emergency response program that can reduce the impacts of a release should be available. 

Mitigation Reducing the risk of an accident event sequence by taking protective measures to reduce the likelihood of occurrence of the event, and/or reduce the magnitude of the event and/or minimize the exposure of people or property to the event. 

The process of engaging the required capabilities must be a formal process so that both the organization in need and the contractor/sub-contractor are protected in the event of a failure to perform, an accident, or a difference of opinion as to terms or performance. Adherence to the provisions of this procedure will help attain good contracting practices and minimize the potential liabilities to the host organization in contractual relationships. 

If Step 7 minimizes consequences, and Step 9 minimizes accident frequency, it would seem perforce the risk would be minimized and such is generally the case. However, there is a synergism when frequency and consequences are combined into risk. While the risk of a low-frequency high-consequence accident may be the same as a the risk of a high-frequency low-consequence accident,... 

The accident sequence frequencies are quantified by linking the system fault tree models together as indicated by the event trees for the accident sequence and quantified with plant-specific data to estimate initiator frequencies and component/human failure rates. The SETS code solves the fault trees for their minimal cutsets the TEMAC code quantitatively evaluates ihe cm sols and provides best estimates of component/event probabilities and frequencies. 

The inventory of long-lived fission products is far less than an LWR because of the short exposure of the fuel to minimize Pu-240 production. But the health effects from an accident are comparable because it primarily results from short lived radionuclides. 

Safety air technology, including risk assessment, that minimizes damages and hazards caused by accidents, fire, and explosion... 

Three major themes have been emphasized in this chapter. The first is that an effective data collection system is one of the most powerful tools available to minimize human error. Second, data collection systems must adequately address underlying causes. Merely tabulating accidents in terms of their surface similarities, or using inadequate causal descriptions such as "process worker failed to follow procedures" is not sufficient to develop effective remedial strategies. Finally, a successful data collection and incident investigation system requires an enlightened, systems oriented view of human error to be held by management, and participation and commitment from the workforce. 

Accidents are a fact of life. Their frequency liave increased with technology and time. Today s problems require more elaborate systems of warnings and controls to minimize the chances of serious accidents. 

These procedures are used to minimize tlie damage caused by these accidents. 

A program to minimize occupational accidents sliould iiicoiporate measures in... 

Although accidents of these types occur infrequently, they may present a greater potential for loss titan fires, explosions, or spills. Since natural disasters are difficult to predict and prevent, one is obliged to rely more heavily on precautions designed to minimize tlie impact of an occurrence of a natural disaster, such as emergency plamting. 

The objective of emergency planning is to reduce die probability of serious loss due to a particular liazardous accident. The probability of an occurrence of a hazardous accident is first evaluated. It is tlien it is assumed tliat, if the accident occurs, tlie worst consequences will follow (tlie so-called worst-case scenario). Procedures for liandling a particular accident are tlien dex eloped and practiced, both to minimize tlie exposure of persoiuiel and to prevent escalation of the original incident. 

The most serious accident tliat Ciui occur in a nuclear plant is a reactor core meltdown. In a core meltdown, the enclosed gases physically melt through tlie reactor vessel, and once contacting with cooler liquids or vapors either in a cooling jacket or in the outer enviromnent, cause a physical e. plosion to occur. However, tlie hazard caused by the e. plosion itself is minimal and more localized compared with the release of radioactive material that accompanies such an accident. 

If the probability of the accident and tlie severity of its consequences are low, then die risk is usually deemed acceptable and the plant should be allowed to operate. If die probability of occurrence is too high or die damage to the surroundings is too great, dien the risk is usually unacceptable and die system needs to be modified to minimize these defects. 

The first step in minimizing accidents in a chemical phuit is to evaluate the facility for potential fires, explosions, and vulnerability to other liazards, particularly those of a chemical miture. This calls for a detailed study of plant site and layout, materials, processes, operations, equipment, and training, plus an effective loss prevention program. The technical nature of industry requires detailed data and a broad range of experience. Tliis complex task, today becoming the most important in plant design, is facilitated by the safety codes, standiu ds, and practice information available. The technical approach to evaluating die consequences of hazards is discussed later in tliis cliapter and in Part V (Chapters 20 and 21). 

Describe how the consequences of an accident at home could be minimized or eliminated. 

Some possible ways to minimize die consequences of accidents in die home are listed below ... 

Traffic and material movement is a major consideration, and should be arranged so that cross flows are minimized and the potential for congestion and accidents reduced. Much useful information on both the analysis and practice of movements is contained in the References. 

People often lack respect for the power in compressed air because air is so common, and it is viewed as harmless. At sufficient pressures, compressed air can cause damage if an accident occurred. To minimize the hazards of working with compressed air, all safety precautions should be followed closely. Reasons for general precautions follow. 

In the event of accident or gross misuse of products, various health hazards could arise. The data provided by the supplier should outline these potential hazards and the simple precautions that can be taken to minimize them. Guidance should be included on the remedial action that should be taken to deal with medical conditions that might arise. Advice should be obtained from the supplier before petroleum products are used in any way other than as directed. 

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