共查询到20条相似文献,搜索用时 15 毫秒
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A modified version of the LIFE-III code, LIFE-GCFR, and classical stress analysis techniques have been employed to calculate the stresses in GCFR cladding under normal reactor operating conditions. Several types of loadings on the cladding which occur during normal operation have been considered. These include fuel-cladding mechanical interaction, thermal stresses induced by radial and axial temperature gradients, and stresses induced by swelling gradients. The combined and individual effects of these loadings as well as the effect of creep on cladding stresses have been assessed. Results obtained from this study have provided input to the experimental GCFR cladding development work at Argonne National Laboratory. 相似文献
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Stephen Kirk Combs L.R. Baylor S.J. Meitner J.B.O. Caughman D.A. Rasmussen S. Maruyama 《Fusion Engineering and Design》2012,87(5-6):634-640
Pellet injection is the primary fueling technique planned for core fueling of ITER burning plasmas. Also, the injection of relatively small pellets to purposely trigger rapid small edge localized modes (ELMs) has been proposed as a possible solution to the heat flux damage from larger natural ELMs likely to be an issue on the ITER divertor surfaces. The ITER pellet injection system is designed to inject pellets into the plasma through both inner and outer wall guide tubes. The inner wall guide tubes will provide high throughput pellet fueling while the outer wall guide tubes will be used primarily to trigger ELMs at a high frequency (>15 Hz). The pellet fueling rate of each injector is to be up to 120 Pa m3/s, which will require the formation of solid D–T at a volumetric rate of ~1500 mm3/s. Two injectors are to be provided for ITER at the startup with a provision for up to six injectors during the D–T phase. The required throughput of each injector is greater than that of any injector built to date, and a novel twin-screw continuous extrusion system is being developed to meet the challenging design parameters. Status of the development activities is presented, highlighting recent progress. 相似文献
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Masanori Onozuka Yasushi Oda Kingo Azuma Kouji Satake Satoshi Kasai Kouichi Hasegawa 《Fusion Engineering and Design》1995,30(4):373-383
A railgun pellet injection system has been developed for fusion experimental devices. Using a low electric energy railgun system, hydrogen pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high speed pellet injection into fusion plasmas. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. Under the same operational conditions, the energy conversion coefficient for the dummy pellets was around 0.4%, while that for the hydrogen pellets was around 0.12%. The highest hydrogen pellet velocity was 1.4 km s−1 using a 1 m long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km s−1 using a 3 m long railgun. 相似文献
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J.H. Gittus 《Nuclear Engineering and Design》1975,32(3):358-362
Because the stresses to which metals are subjected in service are a much smaller proportion of the elastic modulus than are the stresses commonly imposed on rubbery polymers, the coefficient of friction when interfacial dislocations (interfaceons) are present is much lower for metals than for rubber. It is also much lower than the coefficient of friction for ordinary sliding (in the absence of interfaceons) and so the stress concentration predicted to be produced by pellet cracks is negligible if there are interfaceons present. If they are absent then the stress concentration is significant. In either case a low rate of power increase causes the lowest stresses and stress concentrations in the clad. This is shown to be due to relaxation creep in the pellet. 相似文献
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Reliable disposal of radioactive wastes in nanosize containers which ensure that the wastes are isolated and strongly contained
is investigated. A model of the process of incorporating impurity components into solutions where nanotubes are formed is
presented to substantiate the possibility considered. An attempt is made to describe the rolling up of nanotubes in a liquid
medium from the standpoint of the energy balance in a system that consists of a nanometer-size thin film and molecules which
are sorbed on its surface from solution. The results show that when molecules are sorbed from solution onto a nanolayer surface
the layer rolls up. The possibility that a roll or nanotube loses stability when sorbed molecules are present in them must
be taken into account when studying the final state of the nanolayer. 相似文献
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V. I. Danchev 《Atomic Energy》1964,14(3):291-303
Some previously published schemes are given for the classification of exogenous uranium deposits; a brief ctitical review is given of the main principles of the classification; the stages of ore formation are described corresponding to the stages of formation of the ore-containing sedimentary rocks. Finally, a scheme is proposed of a classification which takes into account the conditions of formation and the composition of the ore-containing rocks, and also the dynamics of the ore-forming processes.Translated from Atomnaya Énergiya, Vol. 14, No. 3, pp. 296–308, March, 1963 相似文献
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D.A. Jobson 《Nuclear Engineering and Design》1987,98(3)
Difficult computational problems can arise when analysing structures constructed from materials which are non-linear. It has also to be recognised that the parameters in the relationships which define the latter may show some variability. This can de-value the usefulness of findings which take no account of such variability. Information concerning effects of the latter is obtainable by envisaging the dependent variables as function of a parameter h, the value of which varies from zero for linearly elastic/viscous behaviour to unity for a plasto-rigid material.Generally applicable methods have thus been established for estimating the sensitivity of the stress distribution in a structure and the associated deflections as functions of h. Use has been made of the asymptotic solutions when h → 0 both for this purpose, and to automate computation of so-called reference stresses for structures which may behave in a non-linear fashion, as a result of creep, for example. It is further conjectured that such a development has a potential for affecting the direction of developments from the current position on design by analysis for components and structures which are required to operate under such conditions. 相似文献
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《Fusion Engineering and Design》2014,89(2):99-103
A new hydrogen/deuterium pellet injector has been developed for Experimental Advanced Superconducting Tokamak (EAST). The pellet injector based on a screw extruder is able to fire pellets (∅2 mm × 2 mm; frequency 1–10 Hz and velocity 150–300 m/s) in steady state mode with reliability greater than 95%. An injection line was designed for pumping propellant gas and for diagnostic purpose also. A guide tube for magnetic high-field side (HFS) injection was developed and theoretical calculation has been done. After successful engineering commissioning, the injection system served at EAST 2012 campaign and first experimental results were obtained. 相似文献
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《核技术(英文版)》2016,(6):159-162
An improved thermometer (TIB) is proposed for intermediate-mass fragments via the difference between isobaric yield ratios. The residual free energy of three isobars is replaced by that of the binding energy. The measured fragments in the 140A MeV 40, 48Ca+ 9Be (181Ta) and 58, 64Ni+ 9Be (181Ta) reactions are analyzed to obtain TIB ranging from 0.6 to 3.5 MeV. TIB is suggested to be a direct determination of temperature avoiding the fit-ting procedure. 相似文献
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Conditions for the appearance of thermal stresses in reactors are investigated; also their magnitude and the danger they create are estimated. The influence of the form of the heat-generating elements (HGE) on the temperature drop and magnitudes of thermal stresses is analyzed; recommendations are given with the aim of decreasing the harmful effect of thermal stresses.The methods from the theory of elasticity employed in the calculation of thermal stresses have significant limitations. In many cases when estimating the magnitude and degree of danger created by the thermal stresses, when combining such stresses with mechanical stresses, and also when seeking a way to decrease them, other effects such as fluidity, creep, initial breakdown, and microscopic processes must be taken into consideration. 相似文献
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Hui-Ling Wei Meng-Die Zhou Pu Jiao Yu-Ting Wang Jie Pu Kai-Xuan Cheng Ya-Fei Guo Chun-Yuan Qiao Gong-Tao Fan Hong-Wei Wang Chun-Wang Ma 《核技术(英文版)》2023,(12):114-124
From the empirical phenomena of fragment distributions in nuclear spallation reactions, semiempirical formulas named SPAGINS were constructed to predict fragment cross-sections in high-energy γ-induced nuclear spallation reactions(PNSR).In constructing the SPAGINS formulas, theoretical models, including the TALYS toolkit, SPACS, and Rudstam formulas,were employed to study the general phenomenon of fragment distributions in PNSR with incident energies ranging from 100 to 1000 MeV. Considering the... 相似文献
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This paper is concerned with stress and deformation analysis of a circular cylindrical, thin, elastic shell, representing a nuclear reactor vessel, with an insulated cutout of arbitrary shape subjected to mechanical and thermal loads. The analysis is based on the method of superposition. The actual stresses in the shell may be considered as the sum of the following two parts:
- 1.
- (a) Stresses caused by the given heat flow and mechanical loads in a similar shell without a hole (nominal stress solution); 相似文献