Early Accidents


The steam explosion of the Chernobyl reactor in Ukraine in 1986 caused scores of immediate deaths and released large amounts of radioactivity, with resultant contamination and radiation exposure. The accident occurred because of inadequate inherent safety, improper operating practices, and lack of containment. The Chernobyl accident resulted in some design and operation changes in the reactor, making it less vulnerable in future operation. Countries of the former USSR have been encouraged by the International Atomic Energy Agency (IAEA) and the United States to shut down the reactors, but as of early 1995 demands for electrical power have prevented such action.  [c.181]

Progress toward the disposal of nuclear wastes has been slow for a number of reasons. One is pubHc opposition, epitomized by the not in my back yard (NIMBY), syndrome. Much of the pubHc is fearful of nuclear reactors, radioactivity, and radiation (32). Concern was heightened by the Three Mile Island and Chernobyl accidents. Others in the pubHc oppose siting of disposal faciHties on economic grounds, believing that business, tourism, and property values would be jeopardized. Some people are concerned with equity when a local population must host a site that benefits the state, region, or nation. Efforts by the nuclear community to maintain positive dialogue are often successful, especially when the pubHc is involved in discussions at an early stage of a project, and is fully and correctly informed of plans and developments (33,34). Educational material on radioactive wastes is available (35,36).  [c.232]

Defining the analytical boundaries is a more subjective task. The first requirement is to identify the types of accidents to be considered. Once that is decided, selection of an appropriate level of detail is the scope element that is most crucial to performing an efficient QRA. You should encourage your QRA project team to use approximate data and gross levels of resolution during the early stages of the QRA. Once the project team determines the design areas that are the largest contributors to risk, it can selectively apply more detailed effort to specific issues as the analysis progresses. This strategy will help conserve analysis  [c.27]

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.  [c.940]

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.  [c.8]

Marshall (1990, 1992) discusses accident prevention, control of occupational disease, and environmental protection in terms of strategic and tactical approaches. Strategic approaches have a wide significance and represent once and for all decisions. The inherent and passive categories of risk management would usually be classified as strategic approaches. In general, strategic approaches are best implemented at an early stage in the process or plant design. Tactical approaches include the active and procedural risk management categories. Tactical approaches tend to be implemented much later in the plant design process, or even after the plant is operating, and often involve much repetition, increasing the costs and potential for failure.  [c.15]

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).  [c.146]

The quantification of accident sequences involving fires follows the general methodology for event trees and fault trees. Special attention must be paid to intersystem dependencies introduced by fire. Although early analysis based on simple system reliability models indicated low accident probability, more recent estimates employing sophisticated plant and system-level models give higher risk. These estimates tend to be dominated by the effects of interactions that increase the probability of successive failures in an accident chain. Reactor operating experience indicates that successive multiple failures are more likely to result from human or physical interaction than random events.  [c.199]

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  [c.253]

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.  [c.314]

The relative importance of these pathways varies with the distance from the accident, weather conditions, and the exposure duration. The ingestion dose is usually ignored in computing acute (early) effects. It is impossible to generalize about the relative importance of the other three pathways because their importance varies greatly depending on the radionuclide composition of the release and the organ for which the dose is computed. The doses from immersion, inhalation, and the ground are computed to find the dominant pathway.  [c.324]

IPE accident progression analyses generally are consistent with typical analyses of containment performance. Failure mechanisms identified in the past as important are important in the IPEs. In general, the IPEs confirmed that the larger volume PWR containments are more robust than the smaller BWR pressure suppression containments in meeting the challenges of severe accidents (Table 11.1-4). Containment performance is important to reducing the risk from early releases. Analyses in IPE submittals emphasize phenomena, mechanisms, and accident scenarios associated with early  [c.395]

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.  [c.23]

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.  [c.252]

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.  [c.113]

In-process measures that provide early indication of potential breakdowns which could lead to accidents or other unwanted events.  [c.123]

Number of in-service equipment failures is an early indicator of potential problems. Ideally, maintenance programs ensure that equipment does not fail while in service. Such unplanned failures might, in other circumstances, have resulted in an accident or incident. Tracking in-service failures provides a useful indicator of changes in performance. Monitoring in-service failures led in one case to a recognition that a new additive was damaging valve seals with an associated increase in fugitive losses to the environment. In another situation, such monitoring identified that an increase in the severity of operation was dramatically shortening the tube life in furnaces.  [c.127]

The early nineteenth century saw the beginning of factory production systems, particularly in the cotton mills of Lancashire and woolen mills in Yorkshire. Accidents arising from the use or misuse of steam plant, particularly boilers, became common and led not only to damage and destruction to property but also to death and bodily injury to persons in or about the scene of the explosions.  [c.140]

My company first got involved with eddy currents rather by accident in the mid 60 s. We were not aware that we were dealing with eddy currents nor did we know we were in the NDT field at the time. All we knew was that an engineer in the Navy had an idea of how to find cracks in submarine hull welds without removing the paint. We were a small group of scientists/engineers engaged in sub-contract electronic manufacturing at the time. To solve the problem of finding cracks in submarines we were invited to work with the Navy engineer to build his ideas into a suitable instrument for the Navy to use, we were warned that it had to be sailor proof and very easy to use. The resulting instrument was the AMLEC Crack Detector. Several thousand were sold to navies around the world and instruments delivered in the 60 s and early 70 s remain in use today.  [c.273]

The polymers fkst synthesized (1,2) were reported to be clear glassy resins. This original work involved a thermal polymerization, and it was not until the early 1950s that scientists at Eastman Kodak discovered the rapid room-temperature cure and excellent adhesion of these materials quite by accident. While determining the refractive index of a freshly prepared monomer, they discovered that the glass prisms of the refractometer had become tightly bonded. Further work led to the discovery that many other substrates became bonded in the same manner. This resulted in the commercialization in 1958 of Eastman 910, the fkst in what would become a large family of 2-cyanoacryhc ester adhesives. At present, a number of manufacturers in the United States, Europe, Japan, and elsewhere market extended lines of these adhesives all over the world. Some of the major producers and thek trademarks include Loctite (Prism and Superbonder), Toagosei (Aron Alpha, Krazy Glue), Henkel (Sicomet), National Starch (Permabond), Sumitomo (Cyanobond), Three Bond (Super Three), and Alpha Giken (Alpha Ace, Alpha Techno).  [c.176]

A further assessment is carried out through the definition and measurement of iadustry-average performance iadexes relating to safety. These iadexes have been estabhshed by the utihties, working with INPO, EPRI, and the supphers (24). Each index bears on some aspect of safe operation of the nuclear power plant, ie, industrial safety accident rate, unplaimed automatic scrams, collective radiation exposure, plant capabihty factor, and unplaimed capabihty loss factor. Eive-year goals are estabhshed for average performance of all U.S. plants for each of these performance indexes. A substantial improvement has been made in all of these indexes since the early 1980s. The goals which were set in 1990 to be achieved by 1995 were either met prior to 1995 or ate expected to be met by the end of that year. International performance indexes very similar to those utilized in the United States have been estabhshed for nuclear plants elsewhere in the Western world. Measurement of performance against these indexes also shows significant improvement of reactor performance worldwide.  [c.237]

Safety objectives have been estabUshed to make both ALWRs even safer than the plants of the early 1990s and safer than required by the safety goals estabhshed by the U.S. NRC. The ALWR safety objectives are that there would be only one chance in 10 x 10 per reactor-year that a severe accident would be initiated, a factor of 10 better than the U.S. NRC safety goal. Mitigation of the accident through the containment systems would reduce the risk by another factor of 10, so that the chance that the radiation dose at the boundary of the plant would be as high as 0.25 Sv, the level below which there is no clinically observable effect, would be one in 1 x 10 . An additional objective has been set to limit the level of occupational radiation exposure. No more than 1.00 Sv/yr occupational exposure should be received by all the workers in each plant, an average of about 0.001 Sv/yr. Improved performance objectives have also been set to provide an additional power margin. This places less burden on both the equipment and operators in miming the plant, resulting in increased rehabiUty and lower operating and maintenance costs.  [c.245]

Buried Structures Corrosion of buried pipehnes caused by sulfate-reducing bacteria has been studied for almost a centuiy. Quite by accident, industry has been protecting buried iron-based structures from bacterial damage through the use of cathodic protection. Cathodic protec tion produces an elevated alkahne or basic environment on the surface of the buried structure (pH >10) which is not conducive to microbiological growth. Booth was one of the early investigators to present this finding, but caution should be exercised when using his recommendations. The user of cathodic protection must also consider the material being protected with regarcito caustic cracking a cathodic potential driven to the negative extreme of —0.95 V for microbiological protection purposes can cause caustic cracking of a steel structure. The benefits and risks of cathodic protec tion must be weighed for each material and each application.  [c.2421]

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.  [c.282]

The first large scale nitroglycerin factory in the U.S. was built by George Mobray to con ete the Hoosac Tunnel (4 miles) at North Adams, Massachusetts in 1867. This plant, before ch ng, produced about 1-million pounds of nitroglycerin without accidents in either manufacture or shipment. An early use of nitroglycerin in the U.S. was blasting oil wells to increase their flow of oil. Another use was the construction of the Sutro silver mine in Nevada (1864-1874).  [c.273]

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.  [c.401]

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.  [c.256]

The concepts of accident proneness and risk taking as a personal trait predisposing the individual to a relatively high accident rate was first suggested by three statisticians. Greenwood, Woods, and Yule in 1919. They published an account of accidents sustained by workers in a munitions factory during the First World War and showed that a small minority of workers had more accidents than they would have done if chance factors alone were operating. Despite these early findings, attempts to explain them in terms of personality characteristics have met with little success. Either these characteristics explained only a maximum of 20% of the variance in accident rate, or a factor found to be relevant in one case was found to be irrelevant in others. The concept of accident proneness is discussed in detail in Shaw and Sichel (1971) who conclude that there is little statistical evidence for the trait.  [c.137]

It has been stated that "organizations have no memory" (Kletz, 1993) or, to paraphrase George Santayana (in Life of Reason, 1905), that "organizations that cannot learn from the past are condemned to repeat their errors in the future." Learning from the past means not only taking specific actions to deal with a problem that has caused a significant injury or loss of property, but also learning to identify the imderlying causes of error and the lessons that can be learned from near misses. Near misses are usually far more frequent than actual accidents, and they provide an early warning of imderlying problems that sooner or later will lead to an accident.  [c.147]

In the preceding section, the importance of a comprehensive human reliability modeling approach has been emphasized from the qualitative perspective. However, such an approach is also critical in order to ensure accurate quantification of risk. If significant human contributors to the likelihood of major accidents occurring are omitted, then the probability of the event occurring may be seriously underestimated. Conversely, the role of the human in enhancing the reliability of a system needs to be taken into account. One reason for including humans in engineered systems is that they have the capability to respond to situations that have not been anticipated by the designers of the system. For example, they can prevent an imdesirable outcome (e.g., the major flammable release in the situation described earlier) by taking appropriate action at an early stage in the event.  [c.206]

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.  [c.32]

A plant accident is more likely to luippen during tlie startup of a new plant or a retro fit process because new equipment usually experiences a high failure rate during the early or break-in period. The overall process is best described by the Weibull distribution. The Weibull Distribution or tlie batlitub curve is a tliree-  [c.196]

The safety of refrigeration and air cooling systems had always been an issue due to the toxicity or flammability of most refrigerants. In fact, increasing prevalence of refrigeration caused accidents and deaths, and the bad publicity and restrictive legislation were becoming serious threats to the gi owth of refrigeration and air conditioning. Fortunately, a solution was found when Thomas Midgley, Albert Henne, and Robert McNary invented chlorofluorocarbon refrigerants (CFCs) for Frigidaire. They were introduced in 1930 and, with the realization of their overall importance to health, safety, and the future of refrigeration and air conditioning, CFCs were made available to the entire industry. The CFCs made it possible to engineer air conditioning systems for any application without fear of safety issues. All other refrigerants used for small refrigeration and most air conditioning systems were soon completely displaced. The CFC refrigerants were applied to air conditioning systems in the early 1930s. One early use was in air conditioning for passenger trains. By 1936 all long-distance dining and sleeping cars on U.S. railroads were air conditioned.  [c.26]

Some environmentalists anticipated a major accident like that of the Exxon Valdez. When plaiiiiing for the Trans-Alaska Pipeline took place during the energy crisis of the early 1970s, it was controversial because of the conflicts of balancing the needs of oil  [c.480]

Ill balancing development with social safety, the Soviet Union was a grim outlier. Recent research has revealed a series of Soviet nuclear accidents, many of them concealed from the outside world, begitiiiing with a dramatic waste dump explosion in 1957 near Kyshtym in the Urals that spread more than 2 million Ci over 20,000 sq miles. The explosion of Unit 4 at Chernobyl, north of Kiev, on April 26, 1986, was the worst recorded nuclear accident in histoiyf. It happened when operators were testing a voltage-regulating scheme on turbogenerator 8 when coolant pumps were slowed. Vigorous boiling led to excess steam, slow absoi ption of neutrons, and increased heat in a positive feedback cycle that resulted in meltdown and explosion. By early May, airborne contamination completely covered Europe. Thirty-one people were killed, 200 suffered radiation sickness, hundreds of thousands of people were confined indoors or evacuated, foods that were suspected of being contaminated were banned, and scientists projected some 1,000 extra cancer deaths over the next fifty years. Perhaps most troubling, follow-up investigation faulted Soviet plant design as much as or more than operator error. Following the accident, public opinion shifted sharply against nuclear energy in Europe, but in the United States, the tide already had turned.  [c.854]

Many urban areas are now using video detection systems to monitor traffic flow. The systems, such as Autoscope, detect changes in video pixels to estimate traffic flow and vehicle speeds on freeways and major arterials. Significant differences in average speeds from one monitor to another indicate the presence of an accident between video monitoring locations. With early detection of an incident, rapid accident response teams (either roving the system or staged in specific locations along the system) can be dispatched immediately. Cellular telephones will also play an increasing role in incident detection programs as the cellular network density increases.  [c.1151]


See pages that mention the term Early Accidents : [c.4]    [c.1211]    [c.338]    [c.219]    [c.139]    [c.463]    [c.258]    [c.1]    [c.3]    [c.4]    [c.9]    [c.31]    [c.460]    [c.26]   
See chapters in:

Health, safety and accident management in the chemical process industries  -> Early Accidents