Reactors Nuclear reactor accidents

The previous chapter described the consequences of a nuclear reactor accident. Chemical process accidents are more varied and do not usually have the energy to melt thick pressure vessels and concrete basemats. The consequences of a chemical process accident that releases a toxic plume, like Bhopal did, are calculated similarly to calculating the dose from inhalation from a radioactive plume but usually calculating chemical process accidents differ from nuclear accidents for which explosions do not occur. 

An Approach to Quantitative Safety Goals for Nuclear Power Plants, October 1980. Rasedag, W. F. et al., Regulatory Impact on Nuclear Reactor Accident Source Term Assumptions, June 1981. 

Nuclear reactor accidents d d Pesticides d Uranium mining d Asbestos d PCBs Nuclear weapons... 

This article does not cover the extensive research carried out to delineate the cause and severity of RPTs possible in nuclear reactor accidents. Although there is not universal agreement, the general consensus is that the superheated liquid concept can explain many of these events and, more importantly, can indicate when RPTs are unlikely to occur in hypothetical reactor accidents. 

Crocker DG. Nuclear reactor accidents—the use of KI as a blocking agent against radioiodine uptake in the thyroid—a review. Health Phys 1984 46(6) 1265-79. 

Table 2.2 summarises the results obtained for all of the water samples. A very good correspondence between spiked and experimentally obtained results was observed. A relative experimental error in most cases was <10% indicating the possibility of using these electrodes as an early warning system in the event of a large contamination of natural waters with cesium, such as in the event of a nuclear reactor accident, e.g., Chernobyl, or the detonation of a dirty bomb . 

Loutit, J.R., Marley, W.G. Russell, R.S. (1960) The nuclear reactor accident at Windscale, 1957 environmental aspects. In The Hazards to Man of Nuclear and Allied Radiations. Cmnd 1235. HMSO, London. 

Los Alfaques Three Mile Island, Pennsylvania Propylene transfer Nuclear reactor accident 216 200... 

Chernobyl, Soviet Union Nuclear reactor accident 325 300... 

The Chernobyl nuclear reactor accident in April 1986 caused an epidemic of thyroid carcinomas in children. Vast quantities of... 

Gas explosion in transit caused 100 deaths and 150 injuries One of two reactors lost its coolant, which caused overheating and partial meltdown of its uranium core. Some radioactive water and gases were released. This was the worst nuclear-reactor accident in U.S. history... 

The necessity and the role of Emergency Response Systems in a nuclear reactor accident can be understood from the following arguments. 

Suppose a chamber is filled with an aerosol that is kept well-mixed. The particles are coagulating and at the same time settling and diffusing to the walls. This type of model has been used to analyze the behavior of radioactive particles generated in a nuclear reactor accident and then collected in a vessel specially designed for the purpose. The contents of the containment structure are mixed as a result of natural convection induced by temperature gradients present under postaccident conditions. The effectiveness of the... 

A hydrogen gas bubble developing from a nuclear reactor accident is a highly unusual event and is an example of the particular environment that is required for hydrogen to explode. 

Nuclear reactor accident assessments consider the five Rs ... 

The litnii of superheat of a liquid, also known as the homogenous nucleation limit, represents the deepest possible penetration of a liquid into the domain of metastable states. At constant pressure (P) it is the highest temperature (T) below the critical point that a liquid can sustain without undergoing a phase transition at constant temperature, it is the lowest pressure. The importance of this limit resides in the consequences of the phase transition that eventually occurs when the limit is reached. The phase transition may be explosive or nonexplosive as it relates to such processes as contact vapor explosions in postulated nuclear reactor accidents, spills of liquid natural gas during transport, and burning of fuel droplets. 

As part of the biogeochemical cycle, the injection of iodine-containing gases into the atmosphere, and their subsequent chemical transformation therein, play a crucial role in environmental and health aspects associated with iodine - most importandy, in determining the quantity of the element available to the mammalian diet. This chapter focuses on these processes and the variety of gas- and aerosol-phase species that constitute the terrestrial iodine cycle, through discussion of the origin and measurement of atmospheric iodine in its various forms ( Sources and Measurements of Atmospheric Iodine ), the principal photo-chemical pathways in the gas phase ( Photolysis and Gas-Phase Iodine Chemistry ), and the role of aerosol uptake and chemistry and new particle production ( Aerosol Chemistry and Particle Formation ). Potential health and environmental issues related to atmospheric iodine are also reviewed ( Health and Environment Impacts ), along with discussion of the consequences of the release of radioactive iodine (1-131) into the air from nuclear reactor accidents and weapons tests that have occurred over the past half-century or so ( Radioactive Iodine Atmospheric Sources and Consequences ). 

Pu-239 i.s a silvery-gray metal that becomes yellowish when exposed to air. Most Pu-239 in the environment is in the form of micro.scopic particles that are the remnants of nuclear weapons testing and nuclear reactor accidents. 

Nuclear weapons production and testing facilities (Hanford, WA, Savannah River, GA, Rocky Flats, CO, and The Nevada Test Site, in the United States, and Mayak in the former Soviet Union), also released small amounts. The releases occurred in accidents with nuclear weapons, the reentry of satellites that used Pu-238, and by the Chernobyl nuclear reactor accident. 

I. Pharmacology. Iodine-131 is a product of fission reactions and is likely to be a major form of internal radioactive contamination following a major nuclear reactor accident or weapon detonation. Potassium iodide (Kl) serves to block thyroid gland uptake of the radioactive isotopes of iodine (to prevent thyroid cancer) by both diluting the radioactive iodine as well as filling the gland with nontoxic iodine, effecting inhibition of further uptake. For optimal protection, Kl should be administered before or at the time of exposure to inhaled radioactive iodines however, Kl may be initiated up to 3 or 4 hours after exposure. If the exposure to radioactive iodines persists, then even later administration may be of benefit. 

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