Nuclear reactors water-cooled

Separation of Hafnium. Zirconium and hafnium always occur together in natural minerals and therefore all zirconium compounds contain hafnium, usually about 2 wt % Hf/Hf + Zr. However, the only appHcations that require hafnium-free material are zirconium components of water-cooled nuclear reactors. 

Hafnium-free zirconium alloys containing tin or niobium are used for tubing to hold uranium oxide fuel pellets inside water-cooled nuclear reactors. Zirconium —niobium alloys are used for pressure tubes and stmctural components in Canadian, the former USSR, and Germany reactor designs. 

The susceptibility of nickel alloys, principally Alloys 600 and 800 to stress-corrosion in water-cooled nuclear reactor heat-exchanger circuits has received much attention. The influence of both metallurgical variables (e.g. alloy composition, heat-treatment) and water chemistry (additives, inhibitors) have been extensively studied and reviewed. ... 

Alloy 600 Alloy 800 Water-cooled nuclear reactor circuits Usually IG 1. Control alloy composition and processing 2. Control water chemistry 3. Stress relieve after fabrication... 

Water The corrosion resistance of pure niobium in water and steam at elevated temperatures is not sufficient to allow its use as a canning material in water-cooled nuclear reactors. Alloys of niobium with molybdenum, titanium, vanadium and zirconium however have improved resistance and have possibilities in this application. Whilst the Nb-lOTi-lOMo alloy offers... 

M12. Milioti, S., A survey of burnout correlations as applied to water-cooled nuclear reactors, M.Sc. Thesis, Dept, of Nucl. Eng., Penn. State Univ., University Park, Pennsylvania, 1964. 

The effect of flow obstructions on the flow pattern transitions in horizontal two-phase flow was studied by Salcudean and Chun (1983). The practical importance of the problem is related to the use of rod spacing devices in water-cooled nuclear reactors. In general, these devices are expected to affect the flow distribu-... 

Tong, L. S., 1967b, Heat Transfer in Water-Cooled Nuclear Reactors, Nuclear Eng. Design (5 301. (3) Tong, L. S., 1968a, An Evaluation of the Departure from Nucleate Boiling in Bundles of Reactor Fuel Rods, Nuclear Sci. Eng. 33 7-15. (5)... 

Burrill, K.A. "Corrosion Product Transport in Water Cooled Nuclear Reactors - Part 1, Pressurized Water Operation"... 

Compared with most metals, the annual production of hafnium is low. Mainly produced in Ihe United Stales. France, and Russia, the comhined production is in the range of 100 metric tons annually, or less. Several uses have been found for hafnium (11 as a control material in water-cooled nuclear reactors. Also hafnium is an effective flux-depressor in a reactor for absorbing neutrons to decrease the peaks in neutron flux ... 

The most important application of zirconium is in the formulation of the base metal in an alloy of 98% zirconium. 1.5% tin, 0.35% lron-chromium-mckel. and 0.15% oxygen, This alloy is widely used in water-cooled nuclear reactors because of its excellent corrosion resistance up to about 350 in H 0, and its low neutron cross section. Currendy, about 90% of the zirconium produced is used for this application. The excellent corrosion resistance of zirconium to both strong acids and alkalis, particularly its resistance to strong caustic solutions at all concentrations and temperatures, is attracting increasing attention for application in chemical processing equipment, See also Nuclear Power Technology. 

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. 

A common thread in many of the reactor technologies that currently exist or that are under development is the use of water as the heat transport medium (the coolant ). In many respects, water is an ideal coolant, because it has a high heat capacity, can be obtained in a high purity, is inexpensive, has a wide liquid range (0-374.15 °C), is easily handled, and had been used since the dawn of steam power. Thus, in their most fundamental form, water-cooled nuclear reactors (WC-NRs) comprise a nuclear boiler, a heat transport system (piping, channels, steam generators, etc.), a set of turbines (high pressure, intermediate pressure, and low... 

D. D. Macdonald, M. Urquidi-Macdonald, J. H. Mahaffy et al., Electrochemistry of Water-Cooled Nuclear Reactors, Nuclear Energy Education Research, Department of Energy, Washington, D.C., Grant No. DE-FG07-021D14334, Final Report 2006. 

Corrosion Damage in Water Cooled Nuclear Reactors, PSU, Final Report to ESEERCO, EP 93-33, (November, 1996). 

Use Control rods in water-cooled nuclear reactors lightbulb filaments, electrodes, special glasses, getter in vacuum tubes. 

Tewari, P.H. and Campbell, A.B., The surface charge of oxides and its role in deposition and transport of radioactivity in water-cooled nuclear reactors, in Proceedings of the Symposium on Oxide-Electrolyte Interfaces, Alwitt, R.S., ed.. The Electrochemical Society, Princeton, 1973, p. 102. 

The zircaloy series of alloys was developed by the U.S. Navy Nuclear Propulsion Program for service in the core of water-cooled nuclear reactors [R3]. Compared with pure zirconium, these alloys have greater strength and better resistance to corrosion by water or steam. Zircaloy-4 was developed later than zircaloy-2 and became the preferred material, because the nickel in zircaloy-2 promoted the absorption of hydrogen, leading to reduction in ductility. 

Zirconium has a high corrosion resistance and low cross-section for neutron capture (see Section 2.4) and is used for cladding fuel rods in water-cooled nuclear reactors. For this application, Zr must be free of Hf, which is a very good neutron absorber. The main use of pure Hf is in nuclear reactor control rods. Zirconium and hafnium compounds possess similar lattice energies and solubilities, and their complexes have similar stabilities this means that... 

OTHER COMMENTS used in control rods in water-cooled nuclear reactors used in light-bulb filaments, electrodes, special glasses, and vacuum tube getter note powder is normally handled wetted with no less than 25% of water to reduce the fire and explosion risk. 

B.E. Wilde, Corrosion measurements in water-cooled nuclear reactor environments. Corrosion 23 (1967) 379-384. 

S.R. Ortner and C.A. English, Applicability of dose-damage relations to operating reactors, IAEA Technical Meeting Degradation of Primary Components of Pressurised Water-Cooled Nuclear Reactors Current Issues and Future Challenges, Vienna, Austria, 5-8 November, 2013. 

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