Download or read book HIGH TEMPERATURE RADIATION DAMAGE TO GRAPHITE PART I PREPARATION OF GRAPHITES FOR IRRADIATION written by and published by . This book was released on 1964 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Radiation Damage to Graphite written by J. T. Meers and published by . This book was released on 1964 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Damage in Graphite written by J. H. W. Simmons and published by Elsevier. This book was released on 2013-10-22 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Energy, Volume 102: Radiation Damage in Graphite provides a general account of the effects of irradiation on graphite. This book presents valuable work on the structure of the defects produced in graphite crystals by irradiation. Organized into eight chapters, this volume begins with an overview of the description of the methods of manufacturing graphite and of its physical properties. This text then presents details of the method of setting up a scale of irradiation dose. Other chapters consider the effect of irradiation at a given temperature on a physical property of graphite. This book discusses as well the changes in dimensions produced by irradiation and the effects of irradiation on the mechanical properties of graphite. The final chapter deals with the accumulation of stored energy, which is one of the main problems caused by the irradiation of graphite in nuclear reactors. This book is a valuable resource for physicists and chemical physicists.
Download or read book Fundamental Studies of Radiation Damage in Graphite written by Donald G. Schweitzer and published by . This book was released on 1962 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Graphite written by R. E. Nightingale and published by Academic Press. This book was released on 2013-10-02 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Graphite focuses on the development and uses of nuclear graphite, including machining practices, manufacture, nuclear properties and structure, radiation, and electrical resistance. The selection first discusses the applications of graphite in the nuclear industry, machining practices, and manufacture. Discussions focus on early, current, and future applications of graphite, impregnation, graphitization, purification, general machining techniques, and equipment and methods in the nuclear industry. The book then examines the structure and nuclear and properties of graphite. The text evaluates radiation-induced structural and dimensional changes; radiation effects on electrical and thermal properties; and radiation effects on mechanical properties. Topics include radiation effects on crystal structure, electrical resistance, thermoelectric power, magnetoresistance, coefficient of friction, irradiation under stress, and elastic moduli of nuclear graphite. The book also ponders on stored energy, annealing radiation effects, and gas-graphite systems. The selection is a dependable source of data for readers interested in the applications of nuclear graphite.
Download or read book Defect Evolution in High temperature Irradiated Nuclear Graphite written by Steve Johns and published by . This book was released on 2020 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of nuclear graphite subjected to displacing radiation; however, a comprehensive explanation for irradiation-induced dimensional change remains elusive. The macroscopic response of graphite subjected to displacing irradiation is often modeled semi-empirically based on irradiation data of specific graphite grades (some of which are obsolete). The lack of an analytical description of the response of nuclear graphite subjected to irradiation is due in part to the complex microstructure of synthetic semi-isotropic graphites. Chapter One provides a general overview of the application, processing, and irradiation-induced property changes of nuclear graphite. The key properties affected by displacing irradiation include, but are not limited to, coefficient of thermal expansion (CTE), irradiation creep, and irradiation-induced dimensional change. Additionally, historical models of radiation damage in nuclear graphite, including their inadequacies in accurately describing property changes, are discussed. It should be noted that a comprehensive explanation for all irradiation-induced property change is beyond the scope of this work, which is focused on the evolution of novel atomic-level defects in high-temperature irradiated nuclear graphite and the implications of these defects for the current understanding of irradiation-induced dimensional change. Chapter Two is focused on the development of a novel oxidation-based transmission electron microscopy (TEM) sample-preparation technique for nuclear-grade graphite. Conventionally, TEM specimens are prepared via ion-milling or a focused ion beam (FIB); however, these techniques require the use of displacing radiation and may result in localized areas of irradiation damage. As a result, distinguishing defect structures created as artifacts during sample preparation from those created by electron- or neutron-irradiation can be challenging. Bulk nuclear graphite grades IG-110, NBG-18, and highly oriented pyrolytic graphite (HOPG) were oxidized using a new jet-polishing-like setup where oxygen is used as an etchant. This technique is shown to produce self-supporting electron-transparent TEM specimens free of irradiation-induced artifacts; thus, these specimens can be used as a baseline for in situ irradiation experiments as they have no irradiation-induced damage. Chapter Three examines the dynamic evolution of defect structures in nuclear graphite IG-110 subjected to electron-irradiation. As use of fast neutrons for irradiation experiments is dangerous, expensive, and time consuming, electron-irradiation is arguably a useful surrogate; however, comparisons between the two irradiating particles is also discussed. In situ video recordings of specimens undergoing simultaneous heating and electron-irradiation were used to analyze the dynamic atomic-level defect evolution in real time. Novel fullerene-like defect structures are shown to evolve as a direct result of high-temperature electron-irradiation and cause significant dimensional change to crystallites. Neutron-irradiated nuclear graphite IG-110 was supplied by Idaho National Laboratory as part of the Advanced Graphite Creep capsule experiments (AGC-3). Chapter Four reports the preliminary characterization of IG-110 neutron-irradiated at 817°C to a dose of 3.56 displacements per atom (dpa). Shown is experimental evidence of a 'ruck and tuck' defect occurring in high-temperature neutron-irradiated nuclear graphite. The 'ruck and tuck' defect arises due to irradiation-induced defects. The interaction of these defects results in the buckling of atomic planes and the formation of a structure composed of two partial carbon nanotubes. The "buckle, ruck and tuck" model was first theoretically predicted via computational modeling in 2011 as a plausible defect structure/mechanism occurring in high-temperature neutron-irradiated graphite by Prof. Malcolm Heggie et al. Chapter Four shows the first direct experimental results to support the "buckle, ruck and tuck" model. Chapter Five further characterizes nuclear graphite IG-110 neutron-irradiated at high temperature (>=800 °C) at doses of 1.73 and 3.56 dpa. Results show further evidence to support the 'buckle, ruck and tuck' model and additionally show the presence of larger concentric shelled fullerene-like defects. Fullerene-like defects were found to occur in disordered regions of the microstructure including within nanocracks (Mrozowski cracks). These results agree with high-temperature electron-irradiation studies which showed the formation of fullerene-like defects in-situ and give additional validity to the use of high-flux electron-irradiation as a useful approximation to neutron-irradiation. Furthermore, Chapter Five gives valuable insight to unresolved quantitative anomalies of historical models of graphite expansion and may improve the understanding of current empirical and theoretical models of irradiation-induced property changes in nuclear graphite."--Boise State University ScholarWorks.
Download or read book The Effect of Radiation Damage on the Thermal Conductivity of Graphite written by Alan W. Smith and published by . This book was released on 1955 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Damage in Graphite by High Energy Electrons written by I. T. Myers and published by . This book was released on 1962 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book THE H 1 HIGH TEMPERATURE GRAPHITE IRRADIATION EXPERIMENT written by and published by . This book was released on 1961 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A high temperature graphite irradiation experinient was performed in the GETR core to determine the effects of differences in manufacturing, formulation, and graphitization temperatures on radiation-induced eontraction. The experiment was performed at temperatures of 800 to 1200 deg C in an intense fast neutron flux. The maximum integrated exposure of the sample positions was 3.2 x 10?sup 21/ nvt, E> 0.18 Mev, corresponding to approximately 24,000 MWD/AT in a conventional graphite-moderated reactor. All the graphites tested, with the exception of the controls, were needle coke filler, coal tar pitch binder graphites varying mn particle size, graphitization temperature, and impregnation. From theoretical and experitnental considerations, the formulations and treatments were expected to result in a relatively stable graphite in the direction transverse to extrusion. For comparison of the experimental results to existing experience, a conventional graphite, CSF, was used at each irradiation position. The results showed that the graphite most stable to contraction was graphaitized at a high temperature(>3100hC) and made from small particle size (all flour) filler. In all cases, the needle coke graphite contracted at a lower rate than the CSF graphite. Differences attributable to the size of extrusion and/or post graphitization cooling rate were discerned readily. Auxil iary to the purposes of the experiment, the apparent thermnal neutron cross section for Co/sup 58/ (plus Co /sup 58m) was determined. Co/sup 58/ and Co/sup 58m/ are the products of the Ni/sup 58/ (n,p) reaction, which is used widely for fast flux monitoring. Both have large thermal neutron capture cross sections which must be accounted for to prevent error in fast neutron dosimetry. In this experiment, a value was determined for the apparent burn-out cross section of 3750 barns. (auth).
Download or read book Radiation Damage in Graphite III Kinetic Reactions of Interstitial Complexes written by and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dimensional changes resulting from reirradiations and anneals in repeatedly irradiated graphites show that the rate of formation of carbon atoms in interstitial complexes is proportional to the irradiation interval when reactions occur at both ends of the chain. When reaction occurs at only one end of the chain the overall rate of production of interstitial carbon atoms is initially dependent on the exposure and then becomes constant. The rate of decomposition of the complexes appears to depend only on the cross sections (number of carbon atoms) of the complexes. After removal of some of the complexes (by a thermal anneal), initial reirradiations decompose remaining complexes and form the complexes that were removed by the anneal. When the complexes that were removed by the anneal reach their steady state concentrations, further irradiation re-forms the complexes that decomposed. Prolonged reirradiations finally result in the successive formation of new complexes that anneal at high temperatures. (P.C.H.).
Download or read book HIGH TEMPERATURE RADIATION DAMAGE TO GRAPHITE PART II RADIATION DAMAGE IN GRAPHITE written by and published by . This book was released on 1966 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Radiation Damage to Graphite written by J. T. Meers and published by . This book was released on 1966 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book US UK Graphite Conference written by and published by . This book was released on 1959 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The H 1 High Temperature Graphite Irradiation Experiment written by J. M. Davidson and published by . This book was released on 1961 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Graphite Problems in Air cooled Reactors written by Donald G. Schweitzer and published by . This book was released on 1962 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Review of High temperature Graphite Irradiation Behavior written by and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The irradiation behavior of reactor graphites at high temperatures (500° to 1400°C) to high fluences (up to 4 x 1022 n/cm2) is reviewed. Recent data generated during the period 1965 through 1971 are emphasized. The review covers graphite manufacture, irradiation damage, dimensional and structural changes, thermal expansion, thermal conductivity, Young's modulus, strength, and irradiation-induced creep.
Download or read book TID written by and published by . This book was released on 19?? with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
