Electricity from nuclear reactions

Since the dominant sources of all radioactive wastes are associated with energy production via nuclear reactors, it seems prudent to discuss nuclear waste in the context of the nuclear fuel cycle. The nuclear fuel cycle consists of all the relevant activities that must be undertaken to produce electricity from nuclear reactions. The schematic of the nuclear fuel cycle is shown in... 

The enormous amounts of energy produced from nuclear reactions makes them a logical choice for energy production. Essentially, the generation of electricity by nuclear means occurs as follows. 

In order to make electricity from nuclear fission, the fission reaction must be carefully controlled. To do that, the number of neutrons must also be kept under close control. Hafnium has the ability to absorb ( soak up ) neutrons very easily. It is used in rods that control how fast a fission reaction takes place. This property is one of the few ways in which hafnium differs from zirconium. Although hafnium is very good at... 

Cooling towers are used in many industrial areas to cool water to remove excess heat produced by fuel combustion or by other reactions. Nowhere is more cooling water used than in the production of electricity from nuclear fission. In virtually every cooling tower application, cool water is taken from a surface source (river, estuary, or lake) and is returned to its source heated up. The introduction of warmed water to its source disrupts marine plant and animal life and also catalyzes chemical reactions. These have the effect of increasing the concentrations of toxic chemicals in water, which is often taken up for drinking use downstream... 

Nuclear power is a major source of energy for electrical generation worldwide. Nuclear power plants are found in over 30 countries and generate about 17% of the world s electricity. France gets about 76% of its electricity from nuclear power, Japan gets about 33%, and tbe United States gets about 22%. Special Topic 18.1 A New Treatment for Brain Cancer describes another use for a fission reaction. 

One type of reactor uses metal slugs containing uranium enriched from the normal 0.7% U-235 to about 3% U-235. The self-sustaining fission reaction is moderated, or controlled, by adjustable control rods containing substances that slow down and capture some of the neutrons produced. Ordinary water, heavy water, and molten sodium are typical coolants used. Energy obtained from nuclear reactions in the form of heat is used in the production of steam to drive turbines for generating electricity. (See Figure 18.7.)... 

There is a close kinship between the chemical process industry and the nuclear electric power industry. In tact once the physics of nuclear reaction was established the rest is chemistiy and hc.it ii an.sfer. The word "reactor" is from chemistry for the location the reaction takes place.. nuclear reactor consists of a vessel in which a nuclear reaction heats water to make steam to drive a turbine o generate electricity. Thus the primary components are pipes, valves, pumps heat exchangers, and water purifiers similar to the components found in a chemical plant. Following the success of WASH-1400, PSA was used to analyze the chemical proce.ssmg of nuclear fuel and. aste preparation for disposal. 

Plutonium-239 is a fissile element, and vvill split into fragments when struck by a neutron in the nuclear reactor. This makes Pu-239 similar to U-235, able to produce heat and sustain a controlled nuclear reaction inside the nuclear reactor. Nuclear power plants derive over one-third of their power output from the fission of Pu-239. Most of the uranium inside nuclear fuel is U-238. Only a small fraction is the fissile U-235. Over the life cycle of the nuclear fuel, the U-238 changes into Pu-239, which continues to provide nuclear energy to generate electricity. 

Neutrons have no electrical charge and have nearly the same mass as a proton (a hydrogen atom nucleus). A neutron is hundreds of times larger than an electron, but one quarter the size of an alpha particle. The source of neutrons is primarily nuclear reactions, such as fission, but they are also produced from the decay of radioactive elements. Because of its size and lack of charge, the neutron is fairly difficult to stop, and has a relatively high penetrating power. 

Solid State Reaction - Hexaaluminates have been long known as interesting materials for many applications (electrical ceramics, matrices for permanent immobilization of radioactive elements from nuclear wastes and refractory cement and concrete). For many years ceramists prepared hexaaluminates via solid state reaction for both crystallographic and application purposes.6... 

Figure 7 is a graphic description of the kinetic energy required by a deuteron to produce D-D, D-T, and D-helium-3 nuclear reactions. The bottom of the chart depicts the required deuteron kinetic energy level in thousands of electron volts. The x-axis coordinate is labeled from 10° to 103 kilo-electronvolts. The y axis is labeled in terms of the nuclear reaction cross section. Three types of nuclear reaction curves are depicted. Note that each curve rises to a maximum and then decreases in value. The D-D curve is shown with its maximum value at about 1000 keV. Considering the use of a typical ion accelerator, electric potentials ranging from about 10 to 106 keV are used. 

In peaceful uses of nuclear reactions, electrical power plants can be driven by a nuclear reactor very close to criticality, with careful control of neutron flux excess heat from the well-shielded nuclear reactor is driven off by a liquid (H20, Na, or Hg), which in a secondary cycle or a tertiary cycle generates electricity by turning induction turbines. 

Over-unity machines are claimed by their inventors to be emerging, as seen in the late 199Qs. Their mechanisms are far from clear as yet. They seem to involve nuclear reactions under very low temperature situations, or alternatively, they are machines that are claimed to convert the zero point energy of their surroundings to electricity. If (as seems Ukely) they become commercialized in the early decades of the new century, the cost of electricity will fall and a great augmentation of the electrical side of chemistry will occur. 

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