Nuclear radiation, exposure

NATO STANAG 2083 -Commanders Guide on Nuclear Radiation Exposure of Groups. 

Nuclear wastes are generated from spent nuclear fuel from electric power plants, dismantled weapons, and products such as radio pharmaceuticals. The most important design item for the safe storage of nuclear waste is the effective shielding of radiation. To reduce the probability of nuclear radiation exposure, special packaging is designed to meet the protection standards for temporary dry or wet storage or for... 

Radiation dose limits at a disposal site boundary are specified by the NRC as 25 x 10 Sv/yr (25 mrem/yr), a small fraction of the average radiation exposure of a person in the United States of 360 x 10 /Sv/yr (360 mrem/yr). Protection against nuclear radiation is fully described elsewhere... 

If possible comparisons are focused on energy systems, nuclear power safety is also estimated to be superior to all electricity generation methods except for natural gas (30). Figure 3 is a plot of that comparison in terms of estimated total deaths to workers and the pubHc and includes deaths associated with secondary processes in the entire fuel cycle. The poorer safety record of the alternatives to nuclear power can be attributed to fataUties in transportation, where comparatively enormous amounts of fossil fuel transport are involved. Continuous or daily refueling of fossil fuel plants is required as compared to refueling a nuclear plant from a few tmckloads only once over a period of one to two years. This disadvantage appHes to solar and wind as well because of the necessary assumption that their backup power in periods of no or Httie wind or sun is from fossil-fuel generation. Now death or serious injury has resulted from radiation exposure from commercial nuclear power plants in the United States (31). 

Thousands of studies of radiation and its risks have been conducted. Yet there is no conclusive evidence that low levels of radiation exposure cause either cancer or birth defects. The nuclear iadustry operates oa the coaservative ALARA approval, assumiag that any exposure iavolves some risk. 

For radiation doses <0.5 Sv, there is no clinically observable iacrease ia the number of cancers above those that occur naturally (57). There are two risk hypotheses the linear and the nonlinear. The former implies that as the radiation dose decreases, the risk of cancer goes down at roughly the same rate. The latter suggests that risk of cancer actually falls much faster as radiation exposure declines. Because risk of cancer and other health effects is quite low at low radiation doses, the iacidence of cancer cannot clearly be ascribed to occupational radiation exposure. Thus, the regulations have adopted the more conservative or restrictive approach, ie, the linear hypothesis. Whereas nuclear iadustry workers are allowed to receive up to 0.05 Sv/yr, the ALARA practices result ia much lower actual radiatioa exposure. 

Early in the program, critical components (e.g.,the turbomolecular pump) and circuit boards were tested for their ability to survive neutron and gamma irradiation rates and doses similar to those that would be received from exposure to the detonation of a tactical nuclear device. All components were powered up at the start of the gamma irradiation tests but not during the neutron irradiation tests. Circuit boards were protected by circumvention circuits that powered down critical circuits in 10 to lOOps upon detecting radiation. All components survived the nuclear radiation tests. This unusual performance was noted with positive commendations by the staff at the White Sands Missile Range, where the tests were performed. Tests of the fully integrated CBMS II system, installed in a reconnaissance vehicle, will be conducted in the future. 

After the nuclear explosion at Chernobyl in 1986, Anatoly and other professors and physicians created a foundation, For the Children of Chernobyl. Their goal was to send children abroad for the summers for a reprieve from radiation exposure which impairs their immune systems and has resulted in unprecedented levels of thyroid cancer in children and adults. The first host country to respond to their call for help was India. Before long, the foundation was sending 30,000 children every summer to host families and programs in many countries, including Germany, England, Japan, the U.S., Spain, Italy and France. 

Nuclear power facility safety, 77 531-561 assessment of, 77 538-542 basic principles of, 77 533-536 characteristics of, 7 7 542-551 design of, 77 536-542 first barrier in, 7 7 536-537 fourth barrier in, 77 538 future of, 77 554-557 operational, 77 538 radiation exposure and health standards, 77 551-554 second barrier in, 7 7 537 third barrier in, 77 537-538 Nuclear power plants... 

Occupational radiation exposure, at nuclear power facilities, 17 552-553 Occupational Safety and Health Administration (OSHA), 21 568. 

Radiation exposure standards, at nuclear power facilities, 17 551-554 Radiation furnaces, 12 292-295 Radiation hazards, of niobium, 17 144 Radiation heating, in thermal bonding, 17 511... 

The response to a nuclear explosion differs dramatically from the response to an attack with conventional explosives. When conventional explosives such as dirty bombs disperse radiological materials, the health hazards from the radiation exposure are secondary to the explosion (flying shrapnel, debris, fire, and smoke). In the case of a nuclear explosion, the risks of death, serious short-term health effects, and serious long-term health effects are no longer secondary to the explosion. 

This section describes what happens to the local environment after the detonation of a nuclear weapon. Because it is only a summary, readers are encouraged to seek detailed information from libraries and the Internet on issues such as the workings of nuclear weapons and the technical aspects of radiation exposure. The following discussion is based on Management of Terrorist Events Involving Radioactive Materials, NRCP Report 1381 and Radioactive Hazards in Survival Planning.2... 

Recall that for every seven-fold increase in the hours after a nuclear explosion, the fallout radiation levels drop by a factor of 10. Using the 7/10 rule and the information in Table 5.3, an individual can estimate how much time is available to find a more suitable shelter or gather more resources. Some radiation exposure may have occurred at the time of the explosion and inside a shelter. Therefore, individuals should take care to limit all potential exposure, for example, when gathering resources, to as little as reasonably achievable. 

The intensity of ionising radiation at the earth s surface is not high enough to significantly affect plastics, hence radiation exposure tests are only required in connection with applications in nuclear plant and possibly where radiation is used for sterilisation or to induce crosslinking. 

We receive radiation from outer space as cosmic rays, solar radiation, and upper-atmosphere radiation. The higher the altitude at which you live, the greater will he your exposure to cosmic radiation from space. Since nuclear radiation accumulates in our bodies... 

Tobacco plants accumulate radon from the soil. Uranium from the phosphate fertilizer used on the plants is also another source of radiation. Small amounts of lead-210 are spread on the tobacco leaves. Thus, smokers are exposed to levels of radiation that is about 1,000 times higher than the radiation exposure of workers in nuclear power plants. 

LeSurf, J.E. "Control of Radiation Exposures at CANDU Nuclear Power Stations" J.Brit.Nuc.Energy Soc. (1977) 16 (No. 1) 53... 

X-rays, or gamma rays generated by nuclear decay. Ionizing radiation also includes several types of subatomic particles, such as beta radiation (high-energy electrons) and alpha radiation (helium ions) and others. Medical X-rays are an example of a common beneficial exposure to ionizing radiation. Nuclear radiation is used to generate electricity and cure disease, but is also an important element in military weapons. Uses of nuclear radiation pose serious issues of human exposure and environmental contamination. 

Fig. 3. Schematic illustration of the interface of the nuclear fuel cycle with geochemical/hydrological cycles. The geological repository is the interface for these two cycles. The principal sources of radioactivity (over the long term) are indicated by the radionuclides listed at the centre of each cycle. Total background exposures to radiation are less than 300 mrem/y. The total radiation exposure that can be attributed to the nuclear fuel cycle is less than 3 mrem/y.

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