Early Accidents

One of tlie most legendary disasters occurred in Cliicago in October 1871. Tlie Great Cliicago Fire, as it is now known, is alleged to liave started in a bam owned by Patrick O Leary, when one of liis cows overturned a lantern Tlie O Leary house escaped unlianiicd. since it was upwind of tlie blaze, but tlie bam was destroyed as well as 2124 acres of Chicago real estate. 

In tlie spring of 1889, unusually heavy rains caused die water level of die lake to rise, wliich caused die dam to rupture on May 31. A wall of water 40 feet liigh crashed down into die valley and die city. Tlie lake drained at a rate of 

Ill die Jolmstown flood, diere was no adequate evacuation or Siifety phui. Once die dam had broken, the water reached die city in a matter of minutes - hardly enough dine for a city to react. However, die warnings of inspectors should liave been taken seriously. Joluistown, a city of 30,000 people, was destroyed because of the carelessness and ignorance of a few.  

Specific details regarding the accident and its causes are sparse because, as is usually the case in such a nuuiuiioth disaster, none of the plant operators present at die dine suri ived. Tlie large buildings containing die anunonium sulfonitrate disappeared entirely, mid nothing was left in dieir place 

Some accidents can be attributed to structural failures. On October 20,1944, one of the four liquid gas tanks at tlie East Ohio Gas Company in Cleveland began to leak. The phmt converted natural gas to die liquid form, which was stored for emergency use in holding tanks. If needed, tlie liquefied product could be reconverted to its gaseous state and fed into the city distribution lines. The tanks were consuiicted in 1941 and liad a capacity of more tlian 400.000 cubic feet of liquid. 

As was Uie case in Oppau, Germany, in 1921, everyone with firstliand knowledge of the disaster was killed on the site, leaving tlie cause of the incident unknown. It is reasoned tliat a structural weakness in one of the tanks caused the gas leak, although the liquefied gas was not under any pressure. The tanks were only 3 years old when tlie accident occurred and certainly were not expected to 

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The two well-documented early accidents led to the development of remote-operated facilities. Subsequent misadventures involved no injury to personnel. 

Surveyor Oxfordshire s blanket 30 mph speed limits deliver early accident savings, November 2000... 

An accident complicated by fog, weak winds, and a surface inversion occurred in Poza Rica, Mexico, in the early morning of November 24, 1950, when hydrogen sulfide was released from a plant for the recovery of sulfur from natural gas. There were 22 deaths, and 320 persons were hospitalized. 

Anonymous, How to Prevent Runaway Reactions, EPA 550-F99-004, U.S. Environmental Protection Agency Office of Solid Waste and Emergency Response, August 1999. In addition to the accidents mentioned in the reference, a significant number occurred prior to the 1989 time frame. Serious incidents arc recorded as early as 1957. Accident recording before 1957 was incomplete. 

Inherently safer strategies can impact the accident process at any of the three stages. The most effective strategies will prevent initiation of the accident. Inherently safer design can also reduce the potential for propagating an accident, or provide an early termination of the accident sequence before there are major impacts on people, property, or the environment. 

Safety Monitor is an interactive computer program (Stamm, 1996) that performs real-time assessments of configuration-specific plant accident risk. Originally used at Southern California Edison s San Onofre station in 1994, further development was sponsored by three nuclear utilities and EPRI, to include shutdown operation and expanded user features. It will be enhanced to calculate large early release frequency (a Level 2 risk). 

On the night before and early morning of the accident, a series of human and technical errors caused the water for flushing pipes to pass through several open valves and flow into the MIC tank. The w ater and MIC reacted to produce a hot and highly pressurized gas, foam, and liquid, that... 

The amounts of material released from a damaged plant are usually expressed in fractions of the isotopic quantities in the core. These source terms (meaning source for the ex plant transport) depend on accident physics, amount of core damage, time at elevated temperatures, retention mechanisms, and plate-out deposition of material as it transports from the damaged core to release from containment. This section gives an outline of early source term assessments, computer codes used in calculations, and some comparisons of result.s. 

Risk-based information provides a foundation for regulation of severe accidents. Early PRAs, with large uncertainties, indicated risk that was above or below the Safety Goals depending on containment performance. Consequently the NRC developed an Integration Plan for Closure of Severe Accident Issues (SECY-88-47) with six main elements to this plan 1) individual plant examinations (IPE), 2) containment performance improvements, 3) improved plant oper itions, 4) severe accident research, 5) external event considerations, and 6) accident management. 

Seveso, Italy, caused wide-spread pollution of the industrial site as well as its surroundings. Serious effects of dioxin were detected both in dontestic animals, such as cows and sheep, and in humans, the most serious early effects being a serious skin disease, chloracne, and alterations in the function of the immune system. Follow-up studies have demonstrated that this accident also increased the cancer risk in exposed individuals. ... 

Lewis (1989) describes the accident, which occurred in Siberia on the night of June 3 and early hours of June 4, 1989. Late on June 3, 1989, engineers in charge of the 0.7 m (28 in.) pipeline, which carried natural gas liquids from the gas fields in western Siberia to chemical plants in Ufa in the Urals, noticed a sudden drop in pressure at the pumping end of the pipeline. It appears that the engineers responded by increasing the pumping rate in order to maintain normal pipeline pressure. 

Other important considerations in the design of an IRS are the data storage and analysis requirements. These need to be considered early in the design of the system if it is to be used to research and display trends effectively. For example, in addition to the answers to specific questions, the accident data analyst may wish to make use of free text descriptions of the circumstances of the accident. This implies that a text-based retrieval system will be required. 

Improvements in safety and environmental performance will come only slowly. Major accidents are rare, even with poorly managed programs, and any reduction in these will be evident only after several years. Areas where early improvements might be expected are spill response and occupational injuries where improved processes should be effective soon after installation. Work place exposure and environmental emissions may improve over a period of several months. 

In-process measures that provide early indication of potential breakdowns which could lead to accidents or other unwanted events. 

Before tlie 1970s, there was little legislation regarding tlie prevention of air and water pollution. Although some of the early laws approached the issue of pollution prc cntion. none of tliis legislation provided for emergency plamiing and response in the event of an accident. 

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