Severity categories accident

Each identified hazard is allocated severity classification according to the defined safety criteria. Accident severity categories are defined to provide a qualitative measure of the consequences resulting from personnel error, environmental conditions, design inadequacies, procedural deficiencies or system, sub-system or component failures. The severity is the worst credible consequence of a hazard (i.e. the worst accident) and is independent of random or systemic failure modes. 

Accident severity category Qualitative description of worst-case credible consequences of hazard. 

As usual, design basis accidents (DBA) are classified in several categories These are... 

In our simulations we investigated the most severe category of injuries, those representing total incapacity during all future time periods. To represent the large loss in utility from such a severe accident we set P equal to 0.1. Workers experience a 90 percent utility loss from an injury holding income constant. 

Another challenge lies in relating the accident assessment to an adequate level of response. It can be difficult to communicate accident severity to other emergency groups. Prompt initiation of a coordinate response is more difficult still, unless a simple way to categorize or classify the event is established. Facilities in threat categories I and n should therefore have a clearly defined emergency classification system. 

There are several categories of accident and each has a particuiar significance in the construction industry. Aii of these accident categories are discussed in consider-abie detaii in iater chapters. The principai categories are as foiiows ... 

Using these probability and severity categories, a risk analysis matrix can be developed for any type of event and used to identify imacceptable risks for the operation. It can also be used to prioritize which risks wiU be addressed—where action is taken to eliminate or reduce them—and in which order. An example risk-analysis matrix is given in Figure 18.1, with high priority cells identified. The highest priority cells are located in the upper left part of the matrix, while the lowest priority cells are in the lower right corner. The approach could be used to compare the impact of many different events, such as roof faU accidents, rock burst events, and mine fires. It can also be used to combine both quantitative and quahtative risks. 

A CSI is essentially the same as an SCI except that systems required to identify CSIs have additional statutory and regulatory requirements that the contractor must meet in supplying those CSIs to the government. For systems required to have a CSI list, HA and mishap risk assessment is used to develop that list. The determining factor in CSIs is the consequence of failure, not the probability that the failure or consequence would occur. CSIs include items determined to be life-limited, fracture critical, fatigue-sensitive, and so on. Unsafe conditions relate to hazard severity categories I and II of MIL-STD-882. A CSI is also identified as a part, subassembly, assembly, subsystem, installation equipment, or support equipment for a system that contains a characteristic, failure mode, malfunction, or absence of which could result in a Class A or Class B accident as defined by DoDINST 6055.7. 

Analysis of events of category (2) is generally similar to that for the severe accidents in category (1). For example, a loss of all heat sinks at high pressure would eventually result in the overheating and failure of one or more pressure tubes this would depressurize the HTS and allow the ECC and/or the moderator to act as a heat sink for the remaining channels. 

Mishap severity categories are defined to provide qualitative measures of the worst credible mishap (i.e. accident) resulting from personnel error environmental conditions design inadequacies procedural deficiencies or system, subsystem or component failure/malfunction as shown in Table B.13. 

Introduction Many types of statistical applications are characterized by enumeration data in the form of counts. Examples are the number of lost-time accidents in a plant, the number of defective items in a sample, and the number of items in a sample that fall within several specified categories. 

The cause of a specific accident frequently places it in more than one category. Each of these sections includes descriptions of several accidents and a summary of the lessons learned. 

The number of Sis, present in today s chemical process industry is overwhelming as discussed by Tixier (Tixier et al., 2002). These indicators are categorized in several ways in literature, for example pro-active versus reactive indicators. Many of these categories are not unambiguous. Some authors, like Kletz (Kletz, 1998) define proactive as prior to the operational phase of an installation while other authors, like Rasmussen et al. (Rasmussen et al., 2000), define pro-active as prior to an accident. In this thesis two categories of indicators are used, i.e. pro-active and reactive indicators. Here the definition of Rasmussen (Rasmussen et al., 2000) is adopted, who defined pro-active indicators as indicators before an accident and reactive indicators as indicators after an accident. Moreover, the pro-active indicators are divided into predictive and monitoring indicators. The monitoring indicators use actual events as a measure for the likelihood, while the predictive indicators predict the likelihood. 

This example shows that the focus was put on deviations that have direct safety related consequences ( high consequence category), such as violation of safety procedures or shortfalls in safety training. However, the normal operation in which this ( indirect safety related) overheating deviation occurred had not been identified as relevant ( low consequence category). Finally this re-occurring deviation caused a similar accident only this time with more severe consequences. 

In California, mixer-loaders and spray applicators who work with toxicity category I and II organophosphates or N-methyl carbamates more than 30 hours per 30-day period are required to have medical supervision. Supervision consists of an interview and a medical examination to determine if a medical condition exists which would make the worker unusually susceptible to poisoning due to cholinesterase inhibition, and to caution the individual about the use of certain drugs such as the pheno-thiazine tranquilizers vdtich potentiate the effects of cholinesterase (ChE) inhibition. Two blood samples, taken several days apart, are analyzed to determine the individual s preexposure plasma and red blood cell (RBC) ChE activity (baseline value). The physician arranges a routine ChE testing program and provides for extra ChE tests should the worker be accidently exposed to OP s. If ChE activity is depressed to 50 percent of the baseline value, the physician may ask the employer to place the worker on... 

NUCLEAR HAZARD CATEGORY 2 FACILITIES. This category requires use of one of several analytical methods for developing qualitative accident scenarios. The choices are generally compatible with the requirements of the PSM Rule. If the PSM Rule requirements for PrHAs are met, the resulting analysis should significantly contribute to the analysis required under the DOE-STD-1027-92 for release mechanisms. However, analyses beyond PSM Rule requirements may be needed to comply with other SAR requirements for Nuclear Hazard Category 2 Facilities. 

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