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Graphene-Based Nano-Composite Material for Advanced Nuclear Reactor: A Potential Structural Material for Green Energy
Published in Uma Shanker, Manviri Rani, Liquid and Crystal Nanomaterials for Water Pollutants Remediation, 2022
Materials that are commonly used for commercial reactors, are not suitable for the Gen-IV design due to their higher operating temperature as well as higher neutron dose. For a typical example, zirconium alloys are widely used as fuel cladding and other reactor components due to their low neutron absorption cross-section, moderate mechanical and corrosion resistance at high temperature (at an operating temperature of ª350°C) and aqueous environment (Murty and Charit 2008). With an increase in the operating temperature, zirconium alloys suffer from hydrogen embrittlement due to hydride formation, oxidation, allotropic phase changes and poor creep properties. Some of the outer core components (such as pressure vessel, piping, etc.) are typically made from low alloy steel, need to replace due to their poorer mechanical response and irradiation resistance at high temperatures. Several potential material candidates are listed in Table 2 and Figure 3 exhibiting promising performance as a structural material for Gen-IV reactors.
Reactor Accidents, DBAs, and LOCAs
Published in Robert E. Masterson, Nuclear Reactor Thermal Hydraulics, 2019
In thermal water reactors where zirconium or zirconium alloys are used, the zirconium in the cladding reacts with hot water and steam above 1,200°C to form zirconium dioxide and hydrogen gas. The equation governing this reaction is
Nuclear Fuel Fabrication
Published in Kenneth D. Kok, Nuclear Engineering Handbook, 2016
The zirconium alloys used in PWR nuclear components consist of both zirconium–tin alloys and zirconium–niobium alloys. PWRs have historically used Zircaloy-4, which consists of 98.23 weight % zirconium with 1.45% tin, 0.21% iron, 0.1% chromium, and 0.01% hafnium.
The effect of adding lanthanum nitrate on anodizing process of zirconium-niobium alloy
Published in Inorganic and Nano-Metal Chemistry, 2020
Mohsen Asadi Asadabad, Ramin Shoja Gharabagh
One of the special properties of zirconium alloys is excellent corrosion resistance, which results in their widespread use in fission nuclear reactors.[1] At room temperature an oxide film with a thickness about 2–5 nm is formed on the surface of zirconium alloys.[2,3] Although, the oxide film improves corrosion resistance, at high temperatures the reaction of zirconium oxide with steam results in problems such as release of hydrogen gas. The penetration of this gas into the fuel rod and the formation of hydride phases will have a destructive effect on the performance of the fuel complex. Increasing the thickness of the oxide layer can improve the corrosion resistance and delay the formation of the hydride phase.[4] Anodizing is an electrochemical process that thickens oxide layers formed on active metals such as aluminum, zirconium, and tantalum.
Simulation of atomic displacement cascades in the binary alloy Zr-1%Nb near symmetrical tilt grain boundaries by molecular dynamics method
Published in Radiation Effects and Defects in Solids, 2018
P. Kapustin, V. Svetukhin, M. Tikhonchev
Zirconium alloys are the basic materials for the structural elements of reactors on thermal neutrons. Widely used alloys are E110, E125, E635, Zircaloy 2 and 4 and M5, which have different composition and characteristics. From experimental data, it is known that Nb atoms in Zr–Nb alloys dissolved partially in Zr matrix before radiation exposure. The other part of Nb atoms in such alloys form the β-Nb precipitates. Further radiation exposure leads to growth and change of the composition of these precipitates (1–4). However, the characteristics of these processes at small time intervals (such as atomic displacement cascades) cannot be studied by experiment. To solve this problem, different methods of computer modeling are used. One of them is the molecular dynamics method, which is widely used to simulate radiation damage in different materials (like iron, copper, vanadium and some of their alloys) (5–11). However, the evolution of cascades near grain boundaries (GBs) has not been studied well enough. The results of such simulation should be considered as initial within the framework of the multiscale modeling approach for further simulation of the microstructure changes of Zr–Nb alloys at longer time periods and scales.
Machining and optimization of Zircaloy-2 using different tool electrodes
Published in Materials and Manufacturing Processes, 2021
Jitendra Kumar, Tarun Soota, S.K. Rajput, Kuldeep K. Saxena
Zirconium alloys have high corrosion resistance, low thermal neutron absorption capacity, and high ductility. Due to bio-compatibility, it is used in knee and hip implants in human body. High corrosion resistance makes it suitable for use in chemical, liquefied natural gas, and oil industries. In nuclear industry, Zircaloy-2 was used for cladding fuel rod. Non-traditional machining EDM (electrical discharge machining) has a capability to produce dies and molds, parts for the aerospace industry, structural component of the nuclear power plant, surgical components, and so on with high precision and accuracy.[1] High strength material can undoubtedly machine utilizing EDM with high precision and accuracy.