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Showing 1 to 20 of 61 for “"Fission products"”.
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Separation of fission products from irradiated uranium by peroxide precipitation
… plants or in purifying column extraction products from salvage processes. A search of the unclassified literature had rendered no information upon the feasibility of separating fission products and fuel cladding materials by selective precipitation of uranium peroxide.</p><p>The primary …
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Identifying short-lived fission products by delayed gamma-ray emission
… 45 minutes to allow for the saturation of fission products. The first method used the beam port shutter and allowed for longer counting and irradiation times, but was unsuitable for examining fission products with half-lives below 10 seconds. The on/off method used a cycle of equal …
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The rate of decay of fresh fission products from a nuclear reactor
Determining the rate of decay of fresh fission products from a nuclear reactor is complex because of the number of isotopes involved, different types of decay, half-lives of the isotopes, and some isotopes decay into other radioactive isotopes. Traditionally, a simplified rule of t-1.2 or 7s and …
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A study of fission products in the region of mass numbers 103 to 131
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 1955
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Measurement of energies of gamma-rays following the decay of Np-239 and fission products of U-235
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1961.
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Yield, Kinetic Energy, Pairing Effect, and Shell Effect of Light Fission Products for Thermal-Neutron Fission of Uranium-233
… chamber to determine the yields of light fission products for thermal-neutron fission of U-233. HIAWATHA has an energy resolution of 0.3%, a mass resolution of 0.5 amu, and an atomic-number resolving power of 38. The yields were measured as a function of mass number, atomic number, and …
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Implementation of vented fuel assemblies in the supercritical CO₂-cooled fast reactor
… is particularly well suited to venting, allowing fission products to diffuse into a common header before being routed along a vent path and eventually being released to the primary coolant system. A set of equations were developed which model the transport of fission products from fuel to vent …
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The preparation and characterisation of highly selective adsorbents for fission product removal from acid solutions
… interest in the extraction of short-lived fission products such as caesium and strontium, which play critical role during high-level waste handling and disposal. The PUREX process for reprocessing of irradiated fuel has been unchallenged for more than half a century even though it has …
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Species Chemistry and Electrochemical Separation in Molten Fluoride Salt
… one challenge presented by this reactor is that fission products may leak into the primary system from its TRISO particle fuel during normal operation. Consequently, the circulating fission products within the primary coolant would be a potential radioactive source. On the other hand, the …
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Analytical Separation of Zirconium-95 and Niobium-95 from Uranium Irradiated by Thermal Neutrons
… of the problem, methods For the separation of Fission products have been reviewed. An investigation was conducted into the ability of silica gel, in a medium of hydrochloric acid, to separate zirconium and niobium From an irradiated uranium sample and from 4 non-radioactive sample. Different …
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Heat and Mass Transfer in Reactor Core During a Loca-Single Channel Analysis (Mixed Convection, Numerical, Flow, Thermal-Hydraulics)
… the residual water inventory is boiled off by fission products decay heating. For the Three Mile Island (TMI-2) reactor, it was reported that the steam oxidation of Zircaloy reached such an extent that radioactive gases leaked from the interior of the fuel rod and contaminated the primary …
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Experimental investigations of the thermodynamic properties of Nd-C and Ce-C binary systems for TRISO fuel applications
… to safety through thorough understanding of fission product behaviour, studied and analyzed here using experimental techniques and comparisons to existing literature. Significant knowledge gaps exist in the thermodynamic behaviour of neodymium carbide and cerium carbide fission products that …
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Estimate of radiation release for MIT research reactor during design basis accident
… at the MIT Research Reactor (MITR), radioactive fission products may be released from melted fuel plates into the containment. To comply with regulations, the whole-body dose and thyroid dose at the boundary of the exclusion area as a result of this accident are determined. The fractions of the …
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Quantifying the adhesion of noble metal foulants on structural materials in a Molten Salt Reactor
… Salt Reactor (MSR) Experiment (MSRE), selected fission products deposited on the wetted surfaces throughout the reactor. Fission products such as molybdenum and ruthenium are noble with respect to the electrochemical potential of the fluoride fuel salt and therefore remain insoluble in their …
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Multiphysics modeling, study, and analysis of atmospheric pressure plasma-based mass separation system for high-level radioactive waste treatment
… is for bulk elements with 1–65 amu, 0.7% is for fission products with 80–160 amu, and 0.4% is for actinides with 225–250 amu. Of this waste, 99.7% of the radioactivity comes from the fission products, while substantial bulk elements contribute only 0.1% of the radioactivity. Therefore, clean …
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Coating Parameters of Zirconium Carbide On Advanced Triso Fuels
… reliability to retain both gaseous and metallic fission products created in irradiated UO2. Most research devoted to TRISO fuel particles has focused on the characteristics and retention ability of silicon carbide as the main barrier against metallic fission products. This work investigates the …
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Effects of silver and strontium ions co-implanted into silicon carbide
… is the primary diffusion barrier of radioactive fission products. During normal operations at about 900 ℃ to 1250 ℃, the coated fuel particle retains almost all the radioactive fission products excluding silver (Ag), strontium (Sr) and europium (Eu). Substantial research has been studied on the …
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Effect of helium, strontium and silver implanted into silicon carbide on the structural changes and migration of the implants
Containment of radioactive fission products (FPS) is a cornerstone in the revival of nuclear reactors as a clean energy source. In modern generation IV nuclear reactors, safety is enhanced by coating the fuel kernel with four layers of chemical vapour deposited carbon and silicon carbide (SiC). The …
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Chromatographic Separation of Metals
… fuel (namely uranium and plutonium) from the fission products and other minor actinides produced during the fuel use. The uranium and plutonium constitutes approximately 96 % by mass of the irradiated fuel and for this to be removed, requires large volumes of extractant and equipment with …
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Developing a thermodynamic model for the U-Pd-Rh-Ru quaternary system for use in the modelling of nuclear fuel
Ruthenium, rhodium, and palladium are fission products in nuclear fuels. These elements and their compounds change the properties of fuel pellets. Phase diagrams involving uranium have been constructed experimentally to study fission product behaviour, specifically diagrams containing the very …
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