Nuclear power plant incident

Reinartz, S. (1989). Activities, Goals and Strategies Team Behavior during Simulated Nuclear Power Plant Incidents. In Conference Proceedings, Human Reliability in Nuclear Potver. London International Business Commurucations. 

There were several root causes for the Three Mile Island Nuclear Power Plant incident that occurred in March 1979.Inadequate follow-up to... 

The infamous Three Mile Island nuclear power plant incident occurred partly because the operators became confused between the actual position of a relief valve on the containment building and the indicated position of the relief valve on their control panel. 

Considering the relatively small, controlled amount of com-husfihles in an LWR, it is surprising Jiiit fiiL S at nuclear power plants. should be important. The first incident to attract attention was the fire in the San Onofre cable trays (FRPJ). This was followed by spontiiiieous combustion of uncured polyurethane foam in the cable seals at Peach Bottom 1 (1971). The incident at Browns Ferry in 1975 was similar, except that a candle ignited the polyurethane foam. These events showed the effectiveness of fire as an initiator of multiple system failures -... 

Iman, R. L. and S. C. Nora, Modelling Time to Recovery and Initiating Event Fiequency for Loss of Off-Site Power Incidents at Nuclear Power Plants, January 1988. 

According to a recent report [11], the nuclear power plant was the focus of the designers attention the standards used for the nuclear power plant were more stringent than those for the rest of the submarine. In the process industries utilities, storage areas and offplots often get less attention than the main units and are involved in disproportionately more incidents. 

Accident Risk in U.S. Commercial Nuclear Power Plants (WASH-1400). An Analysis of Reportable Incidents for Natural Gas 4.7-19... 

Reported incidences of fretting have continued to proliferate, in particular in blade/disc fixings in both steam and gas turbines, in PWR and AGR nuclear power plants, between the conductors in overhead power... 

On March 28, 1979, a loss of containment incident occurred at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania. An overheated reactor released radioactive steam and water to the atmosphere resulting in a mass evacuation of the surrounding community. Although no direct injuries were attributed to the incident, environmental effects were later observed and public outcry resulted in a slowdown in the growth of the nuclear power industry. 

All this enables us to obtain reliable and full information under the normal work regime of a nuclear power plant and in the case of increased radionuclide emission into the environment (incidents, emergencies). 

Even if terrorists succeeded in detonating an explosive at a reactor site, the health consequences would be limited. The reactor accident at the Three Mile Island, Pennsylvania nuclear power plant caused a small release of radiation, insufficient to cause any radiation injuries. Bypassing several safety systems caused the Chernobyl reactor incident, involving two explosions, fires and reactor core meltdown. This accident caused the following early phase health effects (1) ... 

There are three phases of a radiological accident early, intermediate, and late. The early phase of an incident is characterized by a need to make immediate decisions about protective actions. These actions are based on a nuclear power plants status and dose projections. Recommendations may be shelter in place or evacuation if the dose is greater than 1 rem. 

Increased radioactive fallout was first observed by the control system of a nuclear power plant on the east coast of Sweden after the Chernobyl accident. Nonetheless, no increase has later been observed in thyroid cancer incidence among children in that special region, emphasizing the importance of iodine sufficiency. 

Besides outcome measures, interviews represent a possible data-collection method. Whether directed or not (e.g., Sinclair 1990) they can produce critical incidents, human factors examples, or networks of communication (e.g., Drury 1990a), which have vrilue as part of an audit procedure. Interviews are routinely used as part of design audit procedures in large-scale operations such as nuclear power plants (Kirwan 1989) or naval systems (Mrilone et al. 1988). 

The reporting system now provides a way for operators of each nuclear power plant to reflect on their own operating experience in order to identify problems, interpret the reasons for these problems, and select corrective actions to ameliorate the problems and their causes. Incident reviews serve as important vehicles for self-analysis, knowledge sharing across boundaries inside and outside specific plants, and development of problem-resolution efforts. Both INPO and the NRC issue various letters and reports to make the industry aware of incidents as part of operating experience feedback, as does IAEA s Incident Reporting System. 

The nuclear engineering experience is not perfect, of course, but real strides have been made since the TMI wakeup call, which luckily occurred without major human losses. To their credit, an improvement and learning effort was initiated and has continued. High-profile incidents like TMI are rare, but smaller scale self-analyses and problem-solving efforts follow detection of small defects, near misses, and precursors and negative trends. Occasionally the NRC has stepped in and required changes. For example, in 1996 the NRC ordered the Millstone nuclear power plant in Connecticut to remain closed until management could demonstrate a safety conscious work environment after identified problems were allowed to continue without remedial action [34]. 

Thus, the general health hazard ( risk ) offered by crossing the street of Karl Johan in Oslo may be in the same order as the risk offered by a nuclear power plant the likelihood of an accident happening on the street is far greater than the likelihood of the power plant blowing up, but the consequences of an incident are far greater in the latter case. 

A serious radiation hazard can exist in a nuclear power plant only if some of the fuel is exposed, particularly if it melts. Even if this occurs, in most cases little or no extra radiation will be released to the environment. Up to the end of 1986 there have been about 100 incidents, some of them deliberate experiments to provide data, at nuclear plants involving some of the fuel melting. These events have been analysed and the results used to improve design and safety. 

The Paks Nuclear Power Plant (NPP) experience with respect to development of symptom-based emergency operating procedures (EOPs) was reported. These symptom based EOPs improve the performance of the plant in the event of an incident or accident because they provide a framework within which all critical safety functions can be monitored and appropriate actions taken. They provide a complement to event-based procedures because it isn t possible to anticipate all plant events, particularly combinations of individual events. The Paks NPP staff have integrated the existing event-based procedures with symptom-based EOPs to provide a comprehensive framework to appropriately respond to all abnormal and emergency conditions. 

The defense-in-depth principle remains the fundamental principle of safety for the nuclear power plants of the next generation, with an implementation of several levels of protection. A good way to contribute to achieve a good level of defense in depth is to reduce the number of significant incidents. This involves to look for improvements of the equipment and systems used in normal operation, with a view to reduce the frequencies of transients and incidents and hence to limit the possibilities of accident situations developing from such events. 

According to the major incident/accident reports of nuclear power plants in Korea, the contribution of human errors takes up about 22% of the total events (KINS). The previous study presents that most of the human-related unplanned reactor trip events during the normal power operation are associated with the test and maintenance activities (63%), which are comprised of the plant maintenance activities such as a periodic preventive maintenance , a plannedmaintenance and a corrective maintenance (Kim Park 2008). This means that the test and maintenance activities should be a major subject that needs to be focused on. The hiunan errors intervened during a periodic preventive maintenance and a corrective maintenance mostly lead directly to a trip event, while the hmnan errors during a planned maintenance , which are performed during the period of a plant overhaul, are mostly dormant imtil a triggering event occurs. 

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