Applications in Nuclear Technology

Low-Z ceramics for high heat-flux component materials for fusion reactors have been tested by out-of-pile electron beams and by in-pile TEXTOR limiter tests. While pyrolytic a-BN shows high thermal shock resistivity (and its use on the limiter ion side rules out arcing), the main erosion occurs by sublimation decomposition. There is evidence that superthermal electrons play a significant role in the limiter erosion [143 to 150]. 

Azimuthal heater rod conduction is important for boron nitride insulated rods, which are typically used in out-of-pile sodium tests. Regime maps which give access to the operating regime treatment have been developed [165]. A stress analysis of inertial heat dumps made of a-BN for a nuclear fusion device has been performed [166]. 

The delayed y-ray background for a pulsed n-source which originates from the n-capture by hydrogen at the source is appreciably reduced by loading a-BN in the cooling water of the n-moderator [167]. 

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The Chemistry of Uranium (Including Its Application in Nuclear Technology), by E. H. P. Cordfunke (out of print)... 

It was concluded that the SMM-modifled membranes could be used effectively for rejecting the radioactive compounds in water solutions. Moreover, the radioactivity of the SMMs membranes after 4 h DCMD experiments was substantially lower than that of the commercial membrane TF200 (Table 1.4), suggesting a smaller adsorption of the radionuclides on the SMM-modifled membrane, which can be regarded as an advantageous property and important for further application in nuclear technologies. 

Workshop on reactor physics calculations for applications in nuclear technology, ICTP, Tneste Italy, 12 Feb >16 Mar (1990)... 

Applications to nuclear physics and astrophysics will be dealt in Chapter 15 and Chapter 16. For the applications in vacuum technology see Section 1.6.4. 

Hori, M. (2008), Synergistic Energy Conversion Processes Using Nuclear Energy and Fossil Fuels , International Symposium on Peaceful Applications of Nuclear Technologies in the GCC Countries, Saudi Arabia, November. 

The medical applications of nuclear technology range from in vitro and in vivo injections for diagnostic tests to cobalt radiation for cancer therapy. A new medical specialty was created, a family of compact cyclotrons was developed to provide short-lived nuclides, and a sizable industry evolved to produce technetium. Until the nuclear industry was created, technetium had been missing from the chart of chemical elements because the half-life of the most stable member was too short, 21,000 years. Technetium and several other nuclides of importance here are discussed elsewhere in the chapter in connection with their production (see Table 21.19).60,61... 

Today the Swedish programme consists of 11 LWR reactor units at 4 sites generating about half of the Swedish electricity, a fuel fabrication plant, a nuclear research centre and extensive application of nuclear technologies in medicine, research and industry. 

Radiation-induced processes at solid-liquid interfaces are of significant importance in many applications of nuclear technology. In water-cooled nuclear reactors, ionizing radiation induces reactions in the water as well as in the interface between the coolant and various system surfaces such as the reactor vessel and the fuel cladding. These processes will directly or indirectly influence the performance as well as the safety of the reactor. In nuclear fuel reprocessing, the significance of radiation-induced interfacial processes is even more obvious. Many countries plan to store spent nuclear fuel in deep geological repositories. 

The chemistry of heterogeneous systems is far from restricted to nuclear technological applications. In heterogeneous catalysis, corrosion science, surface polymerization, biochemistry and many industrial applications such as liquid-liquid extraction, interfacial processes are of vital importance. In nuclear technological applications, the presence of ionizing radiation increases the complexity further. 

Continuous development of membrane processes applied in nuclear technologies is of considerable interest. Implementation of new membrane materials with high chemical and radiation resistance, and new module designs allow spreading applications of membrane processes into different fields of nuclear industry. The main barriers in the use of membrane methods are the... 

Nuclear magnetic resonance (NMR) is a versatile and highly sophisticated spectroscopic technique which has been applied to a growing number of diverse applications in science, technology and medicine. We will consider, for the most part, magnetic resonance involving and C nuclei. 

The use of glass is not restricted to the cases mentioned above. Among other applications, mention can be made of those in nuclear technology (protection from radiation, immobilization of radioactive waste by fusion into a chemically resistant glass, etc.), in agriculture (as carrier for fertilizers with long-term effects) and a number of possible applications in electronics (cf., for example, the survey paper by McMillan, 1976). A separate chapter is devoted to the so-called glass-ceramics. 

Although many metal hydrides decompose at temperatures well below their melting points [1], there have been comparatively few studies of the kinetics and mechanisms of these hydrogen evolution reactions. Much of the interest in solid hydrides has been concerned with their thermodynamic properties, as hydrogen sources in fuel cells, or as reducing agents, or for technological applications in nuclear processes. 

The 1960s were marked by increasing interest of nuclear industry in volatile compounds of metals. Not to mention UF6, which had been exploited from the mid-1940s. Much effort was devoted to developments in the fluoride reprocessing of spent nuclear fuel. At that time, transition metals like Zr, Nb and Ta found many applications in nuclear industry. Some technologies for the extraction of these elements from ores and for the production of pure metals were based on the use of... 

Among the pentavalent elements, the most important are niobium and tantalum. Niobium is an excellent material for surface treatment of steel materials for chemical industry due to its high hardness and corrosion-resistance in wet acidic conditions. Nowadays, niobium is also used for the preparation of superconductor tapes and it is used in other branches of industry, for instance in nuclear technology and metallurgy. Tantalum is also of similar importance. For these applications, it is necessary to prepare high purity metal. Molten salt electrolysis, as an alternative process to classical thermal reduction, provides niobium and tantalum with required quality. In order to optimize these processes, it is necessary to know details of both complex formation and redox chemistry of the species present in the melts. 

Although the isotopes of an element have very similar chemical properties, they behave as completely different substances in nuclear reactions. Consequently, the separation of isotopes of certain elements, notably from U and deuterium from hydrogen, is of great importance in nuclear technology. Table 1.5 lists isotopes important in nuclear power applications, together with their natural abundance and processes that have been used or proposed for their separation. In addition to applications mentioned earlier in this chapter. Table 1.5 includes the use of D and Li as fuel for fusion power, a topic treated briefly in Sec. 9, following. 

In addition to the examples given in this chapter, important applications of non-aqueous solvents include the separation of uranium and plutonium in nuclear technology (see Box... 

S. M. Bowman and M. D. DeHart, Validation of SCALE-4 for Burnup Credit Applications, Accepted for publication in Nuclear Technology. 

Liquid metal corrosion is of considerable interest in nuclear technology as reactor coolants and, in the case of uranium, dissolved in liquid bismuth as reactor fuel. Next to neutron capture cross section and melting point, corrosiveness or containability is perhaps the most important criterion limiting the use of liquid metals for such applications. Alloys of tin, zinc, aluminum, and magnesium, for example, are ruled out primarily by their corrosiveness. A major incentive for the use of liquid metal coolants instead of water is the achievement of higher reactor temperatures. Corrosion usually sets the maximum temperature limit in such reactors. 

Zakrzewska-Trznadel, G., Harasimowicz, M., Chmielewski, A.G., Membrane processes in nuclear technology— Application for liquid radioactive waste treatment, Sep. Purif. Technol. 22-23, 617, 2001. 

In addition to the examples given in this chapter, important applications of non-aqueous solvents include the separation of uranium and plutonium in nuclear technology (see Box 7.3), and the analytical separation of many metals. Supercritical CO2 is a non-aqueous solvent for which applications are rapidly increasing in number, and we discuss this solvent and other supercritical fluids in Section 9.13. 

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