Electrical accidents

American Industrial Hygiene Association Laboratory Safety and Health Committee. Laboratory Safety Incidents available at http //www2.umdnj.edu/eohssweb/aiha/accidents/electrical.htm. 

Electric burns, and electric shock combined with burns, account for most of the work-related reported electrical accidents. Electric shocks on their own, although very common occurrences, are infrequently notified to the enforcement authorities. This is because an electric shock injury only needs to be reported if it results in death or unconsciousness, or in the injured person being detained in hospital for 24 hours or longer, or in the person... 

Science AppHcations, Inc., Status Report on the EPRI Fuel Cycle Accident Risk Assessment, Report EPRI-NP-1128, Electric Research Power Institute, Palo Alto, Calif., July 1979. 

Safety Showers. Safety showers and eyewash fountains or hoses should be installed where corrosive or toxic materials are handled. A large-volume, low velocity discharge from directly overhead should effect continuous drenching, ie, a minimum flow of 20 L/min (50 gal /min). Water to outside showers may be heated to a maximum temperature of 27°C by an electric heating cable. The valves for all safety showers should be at the same height and relative position to the shower head, and they should operate in the same way and direction. The shower station should be identified by paint of a bright, contrasting color. In areas where chemicals harmful to the eyes may be encountered, an eyewash fountain or spray should be available in case of splash accidents. 

Electrostatic charges are also geaerated whea Hquids move ia coatact with other materials, Hquid or sofld, eg, duriag pumping of gasoliae. Serious iadustrial hazards caused by static ia chemical and related fields have been described (28), and a study of accidents ia the chemical iadustry revealed that 115 out of 1600 accideats, or 7%, were ascribed to static electricity (29) (see Plant safety). 

Static electricity is often a hidden cause in accidents. 

Electrical power Reactor physics Reactor systems Accident phenomenology... 

External events are accident initiators that do not fit well into the central PSA structure used for "internal events." Some "external events" such as fire due to ignition of electrical wires, or flood from a ruptured service water pipe occur inside the plant. Others, such as earthquakes and tornados, occur outside of the plant. Either may cause failures in a plant like internal events. External initiators may cause multiple failures of independent equipment thereby preventing action of presumably redundant protection systems. For example, severe offsite flooding may fli 1 the pump room and disable cooling systems. An earthquake may impede evacuation of the nearby populace. These multiple effects must be considered in the analysis of the effects of external events. 

The accident resulted from a routine safety test of some electrical control equipment at the start of a normal reactor shutdown for routine maintenance. The test was to determine the ability to continue to draw electrical power from a turbine generator during the first minute of coast-down following a station blackout. In a blackout, the reactor automatically scrams and diesel generators start to assume load (about 1 minute required). 

Accident progression scenarios are developed and modeled as event trees for each of these accident classes. System fault trees are developed to the component level for each branch point, and the plant response to the failure is identified. Generic subtrees are linked to the system fault trees. An example is "loss of clcciric power" which is analyzed in a Markov model that considers the frequencies of lo,sing normal power, the probabilities of failure of emergency power, and the mean times to repair parts of the electric power supply. 

The mining facility consists of four major operations 1) mining, ore extraction and transportation, 2) ore processing - treatment with chemical solvents to remove minerals, 3) removing impurities and 4) utilities e.g., electricity, steam, water, air and natural gas provided by the facility s power plant and by off-site suppliers. Accidents in any of these operations can stop the whole process. 

Philadelphia Electric, 1983, Severe Accident Risk Assessment, Limerick Generating Station," Report No. 4161. 

Show the complex iterations between government laws and regulations and the PSA response to not only comply but to protect the process industry. The real impact of the accident at the Three-Mile Island nuclear plant was not radiation, which was within regulations but financial losses to the utility and the acceptance of nuclear electrical f>ower in the United States. The effects of the Bhopal accident were in human life but it also had a profound effect on the chemical industry financially, and its acceptability and growth. Present the mathematics used in PSA in one chapter to be skipped, studied, or relerred to according to the readers needs. 

Before entry is allowed into a vessel or other confined space, the vessel should be isolated from sources of hazardous material by slip-plating or physically disconnecting all pipelines and by isolating all supplies of electricity, preferably by disconnecting the cables. On the whole, these precautions seem to be followed. Accidents as the result of a failure to isolate are less common than those resulting from a failure to remove hazardous materials or from their deliberate reintroduction as described in Sections 11.1 and 11.2. However, the following are typical of the accidents that have occurred. 

Accidents have occurred because hot water was not treated with respect. Five men were killed when a plastic hot-water tank split along a seam [14J. On another plant, a man, about to make some tea, caught his sleeve on the tap of an electric water heater. The heater fell over, 2 gal of hot water fell on him, and he died in the hospital five days later [15]. The heater should have been fixed to the wall. If it had contained a hazardous chemical, it would have been secured, but no one thought hot water was hazardous. Chemicals are not the only hazards on a plant. 

Electrical isolation Heat radiation Cooling coils Recent incidents Vacuum relief valves Accidents at sea Fires Problem sources Emulsion breaking Chimney effects Interlock failure Choosing materials. 

Electrical Failures and Computer Failures Nuclear Accidents Natural Disasters... 

Electrical accidents appear to be caused by any one or any combination of tlirec possible factors unsafe equipment, unsafe installation, or both workplaces made unsafe by the emiromiicnt and misafe work practices. Possible ways to protect people from the hazards caused by electricity include insulation, guarding, grounding, nieclnuiical devices, and safe work practices. These are detailed below. 

Turn off power to electrical equipment before tests and repairs tlien lock and tag it out so it does not turn on by accident. Follow your company s lockout/tagout procedures. 

List several procedures tliat am be instituted at a plant to reduce tlie possibility of a personal electrical accident. 

In addition to assessing a fire s flame cliaracteristies to detennine tlie cause and effect of a fire, knowledge of tlie fire accident type will provide insight into its ignition source and possible fire protection and prevention methods. Electrical, chemical, and metal fires can occur in a solid, liquid, or gaseous pliase. Section 7.3 presents a detmled discussion of tliese fires and tlieir ignition sources. 

Electrical accidents, including electrical arcing, short circuits, and overheated electrical equipment, are tlie leading cause of industrial fires. 

The key to safety in explosives manufacturing is to use isolated high-velocity nitric acid reactors that have only a veiy small hold up at any one time (that is, only a small amount of dangerous material is held up inside the reactor at any time). Units are widely spaced, so any accident involves only small amounts of explosive and does not propagate through the plant. Fire and electrical spark hazards are rigorously controlled, and manpower reduced to the absolute minimum through automation. 

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