7-radiation nuclear potential

Energy Capacity to do work can be chemical, electrical, heat, kinetic, nuclear, potential, radiant, radiation, or thermal in nature. 

In recognition of the importance which reactor safety has assumed, both within the nuclear industry and with the public at large, the remainder of the book is devoted to a study of the safety and environmental aspects of nuclear reactors. After a discussion of the biological effects of radiation, the potential hazards from both routine operation and accidents at nuclear power plants are evaluated in the light of the most recent studies. These are illustrated by reference to incidents such as that at the Three Mile Island reactor. Other... 

The system has proven to be a powerful tool for inspections in the Nuclear industry with the potential of reducing the radiation doses for a highly qualified group of personnel and at the same time ensure a high quality and reproducibility of testing... 

The principal ha2ards of plutonium ate those posed by its radioactivity, nuclear critical potential, and chemical reactivity ia the metallic state. Pu is primarily an a-emitter. Thus, protection of a worker from its radiation is simple and usually no shielding is requited unless very large (kilogram) quantities are handled or unless other isotopes are present. 

Criticality Precautions. The presence of a critical mass of Pu ia a container can result ia a fission chain reaction. Lethal amounts of gamma and neutron radiation are emitted, and a large amount of heat is produced. The assembly can simmer near critical or can make repeated critical excursions. The generation of heat results eventually ia an explosion which destroys the assembly. The quantity of Pu required for a critical mass depends on several factors the form and concentration of the Pu, the geometry of the system, the presence of moderators (water, hydrogen-rich compounds such as polyethylene, cadmium, etc), the proximity of neutron reflectors, the presence of nuclear poisons, and the potential iateraction with neighboring fissile systems (188). As Httle as 509 g of Pu(N02)4 solution at a concentration Pu of 33 g/L ia a spherical container, reflected by an infinite amount of water, is a critical mass (189,190). Evaluation of criticaUty controls is available (32,190). 

This section will deal briefly with some aspects of expls safety peculiar to neutron activation analysis expts. We are concerned here with a) the possible effect of the ionizing radiation dose on the energetic material which will cause it to be more sensitive or hazardous to normal handling as an expl, and b) the potential direct expl hazards involved in the physical and mechanical transportation of samples to and horn the irradiation source and in a nuclear counting system... 

Because nuclear radiation varies considerably in energy, the potential to cause damage cannot be assessed simply by counting the number of emissions. The energy of emissions must also be taken into account. Furthermore, the three different t T)es of nuclear radiation affect human cells to different extents. When the amount, energy content, and t T)e of radiation are taken into account, the result is a measure of the effect of radiation on the human body. This is expressed using a unit called the rem. 

Potential Mossbauer isotopes for nuclear resonance scattering, which are within the spectral reach of synchrotron radiation sources, are summarized in Table 9.5 [118-120], and the synchrotron radiation sources which provide dedicated beam lines for specific Mossbauer isotopes are listed in Table 9.6 (adopted from [85]). 

Table 9.5 Potential Mossbauer isotopes for nuclear resonance scattering, which are within the spectral reach of currently available synchrotron radiation sources...

In the absence of nuclear energy sources, a star contracts on a thermal timescale and radiates energy at the expense of gravitational potential energy. Since, by the Virial Theorem, the total energy... 

Experience from the 1986 Chernobyl reactor accident in the Ukraine shows the potential magnitude and impact of a terrorist attack on a nuclear power plant. The accident involved an explosion in a reactor that releases very high levels of radiation for miles surrounding the reactor site. Low levels of radiation were spread by wind currents throughout Europe and the rest of the world. According to Caldicott 2002,... 

In some circumstances such as may be encountered after a terrorist attack, acute doses may be more important than potential chronic effects. More specifically, high doses of radiation may be immediately dangerous to life and health and could lead to severe injury including sickness, irreparable tissue damage, and death, although the more severe effects would likely only be observed after a nuclear explosion. For the purpose of this discussion, acute exposures are defined as those that occur in a relatively short time (over several days or less) and result in a dose of at least 25-35 rad (0.25-0.35 Gy).6-7... 

It is also unlikely that the doses associated with a dirty bomb will produce even the milder acute effects. Although the observation of acute radiation syndrome may be unlikely after a dirty bomb explosion, doses should be kept ALARA to limit the potential for acute and stochastic effects. The entire range of acute radiation syndrome effects will be observed after an attack with a nuclear weapon, as described in Chapter 5. 

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. 

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