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Hydrochemistry and groundwater isotopes
Published in Ian Acworth, Investigating Groundwater, 2019
In this form of decay, the original element becomes a new chemical element in a process known as nuclear transmutation. This new element has an unchanged mass number A, but an atomic number Z that is increased by one.
Nuclear Power Generation
Published in Takashiro Akitsu, Environmental Science, 2018
Since atom (nucleus of atom) is also only a group of protons and neutrons connected by nuclear force, as in molecules, atoms (nuclides) are not as easy as molecules, and composition may change. Changes in the composition of the nuclei of atoms (change in nuclide) are called nuclear transmutation. A radionuclide, a basic phenomenon in nuclear physics, releases radiation and turns into another nuclide. Radioactive decay is a kind of transmutation, but purely artificial transmutation is based on the reaction by Cockcroft and Walton in 1932. The successful conversion of nuclides using an accelerator has started. Nuclear fission reactions and nuclear fusion reactions are also a kind of transmutation.
New Energy Sources
Published in Fang Lin Luo, Hong Ye, Renewable Energy Systems, 2013
Fission of heavy nuclei is an exothermic reaction, which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place) In order for fission to produce energy, the total binding energy of the resulting elements must be less than that of the starting element Fission is a form of nuclear transmutation because the resulting fragments are not the same element as the original atom.
Improvement of the VVER-1200 Fuel Cycle by Introducing Thorium with Different Fissile Material in Blanket-Seed Assembly
Published in Nuclear Science and Engineering, 2019
Nuclear transmutation is the transformation of the fuel atoms into other different atoms. These atoms are called transuranic atoms. The transuranic atoms are the second main component of the discharged fuel. These atoms are generated from uranium, thorium, or any other heavy atom when they absorb neutrons but don’t undergo fission. These atoms fall in the actinide series. All of these elements are unstable and decay radioactively into other elements. Table VI illustrates the concentration of the transuranic atoms for the suggested fuel types at the EOL. Using 232Th as a fertile material offers a significant advantage over traditional uranium; the thorium fuel cycle could help reduce the production of long-lived radiotoxic waste. The 232Th is unlike depleted uranium as it does not produce plutonium. It is observed that the transuranic atoms mainly exist in the fuel that used 238U as a fertile material such as in the case of SB-1, SB-2, and SB-3.
Neutronic Characterization for a Pressurized Water Reactor Spent Fuel Assembly
Published in Nuclear Science and Engineering, 2023
Rowayda Fayez M Abou Alo, Amr Abdelhady, Mohamed K. Shaat
There are several approaches to the management of SNF and radioactive waste. One of these is nuclear transmutation, which is designed to reduce the level of accumulated radioactivity. Transmutation means exposing long-lived radioactive nuclei to neutrons, which are ultimately converted into stable nuclei. Transmutation of radioactive waste is considered by the world scientific community to be an integral part of the future nuclear fuel cycle. It allows for the transformation of long-lived radioactive nuclides into a stable state or for nuclides with a shorter half-life, reducing the amount and hazard of waste to be finally disposed of and easing the requirements for long-term storage.[12]
Measurements of thermal-neutron capture cross-section of Cesium-135 by applying mass spectrometry
Published in Journal of Nuclear Science and Technology, 2020
Shoji Nakamura, Yuji Shibahara, Atsushi Kimura, Osamu Iwamoto, Akihiro Uehara, Toshiyuki Fujii
In recent years, transmutation researches have been revived. The ‘ImPACT’ program (Impulsing Paradigm Change through Disruptive Technologies Program) [2] incorporates one of these movements into its program as a project. The ImPACT program aims to create scientific and technological innovation that will bring great change to the way of industry and society when realized. One of the projects in this program is ‘Reduction and Resource Recycling of High-level Radioactive Waste through Nuclear Transmutation’, which discovers an unprecedented and new route of transmutation and establishes a rational transmutation method, and then the project will challenge the problem of nuclear radioactive wastes. In this project, LLFP nuclides to be transmuted are listed as 107Pd, 93Zr, 135Cs, and 79Se. When considering transmutation of these LLFP nuclides by using neutrons, accurate data of neutron capture cross-sections are required to evaluate transmutation or reaction rates. For two nuclides (107Pd [3] and 93Zr [4]) among them, neutron capture cross-section measurements have been performed at Japan Proton Accelerator Research Complex and Institute for Integrated Radiation and Nuclear Science, Kyoto University. For the remaining two nuclides of 135Cs and 79Se, it is very difficult to obtain even standard solutions in commercial as well as simple substances. For this reason, the measured cross-section data for 79Se(n,γ) reaction are not at all available. On the other hand, experimental cross-section data for the 135Cs(n,γ)136Cs reaction are plotted in Figure 1 [5–10]. A few measurements have been reported for the neutron capture cross-sections of 135Cs from the year 1950s to the beginning of the 2000s. References [5–9] discuss measurements of the cross-sections of the 135Cs(n,γ)136Cs reaction by neutron activation method. For example, Katoh etal. [7] derive the thermal-neutron capture cross-section by performing neutron irradiation with JRR-3M using 135Cs contained as an impurity in a standard 137Cs solution. Anufrev etal. [10] first irradiated natural CsCl samples with reactor neutrons for a long period, and produced the sufficient amount of 135Cs nuclide required for the experiments by the double neutron capture reaction: 133Cs(2n,γ)135Cs. Next, they conducted transmission experiments with the generated 135Cs samples to derive resonance parameters of 135Cs in the neutron energy region shaded in Figure 1.