Download or read book Surface Area burnoff Correlation for the Steam graphite Reaction HTGR written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The oxidation of core graphite by steam of air represents a problem area of significant concern in safety analyses for the high temperature gas cooled reactor (HTGR). Core and core-support graphite integrity and strength deteriorate with oxidation of the graphite, and oxidation furthermore could affect the rate of fission product release under upset conditions. Consequently, modeling of core response during steam or air ingress conditions requires an expression for the rate of graphite interaction with those impurities. The steam--graphite reaction in particular is a complex interaction of mass transport within the graphite with chemi-sorption and reaction on accessible surfaces; experimental results from graphite to graphite are highly variable, and the description of the reaction is not yet completely consistent. A simple etch pit model relating surface area to burnoff has been proposed and shown to provide reasonable correlation with experimental data obtained from steam oxidation studies of nuclear grade H-327 graphite. Unaccounted differences between theory and experiment arise at burnoffs exceeding 3 to 5 percent. The model, while not complete nor comprehensive, is consistent with experimental observations of graphite oxidation by O2(air), CO2, or H2O, and could have some utility in safety analysis.
Download or read book Surface Area burnoff Correlation for the Steam Graphite Reaction written by and published by . This book was released on with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1978 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Japan U S Seminar on HTGR Safety Technology September 15 16 1977 Brookhaven National Laboratory Upton N Y written by and published by . This book was released on 1978 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1978 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Safety written by and published by . This book was released on 1969-11 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1985 with total page 1394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of the American Nuclear Society written by American Nuclear Society and published by . This book was released on 1983 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Steam Oxidation on the Tensile Strength of HTGR Structural Graphites written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The core support system of the General Atomic Company design High Temperature Gas-Cooled Reactor (HTGR) contains type PGX graphite as core support blocks. The change in ultimate tensile strength of PGX graphite specimens with oxidation (burnoff) has been determined in a safety-related experimental program at Brookhaven National Laboratory(BNL). It is shown that Fe, an impurity in PGX graphite, plays a key role in the rate of oxidation. The subsequent failure of the graphite specimens is dependent upon the total weight loss due to oxidation. The results indicate that the loss in tensile strength is exponentially related to the percent burnoff (weight loss), and that grain orientation of the specimen has a significant effect.
Download or read book Corrosion Abstracts written by and published by . This book was released on 1966 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Reacting Surface Density on the Overall Graphite Oxidation Rate written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphite oxidation in an air-ingress accident is presently a very important issue for the reactor safety of the very high temperature gas cooled-reactor (VHTR), the concept of the next generation nuclear plant (NGNP) because of its potential problems such as mechanical degradation of the supporting graphite in the lower plenum of the VHTR might lead to core collapse if the countermeasure is taken carefully. The oxidation process of graphite has known to be affected by various factors, including temperature, pressure, oxygen concentration, types of graphite, graphite shape and size, flow distribution, etc. However, our recent study reveals that the internal pore characteristics play very important roles in the overall graphite oxidation rate. One of the main issues regarding graphite oxidation is the potential core collapse problem that may occur following the degradation of graphite mechanical strength. In analyzing this phenomenon, it is very important to understand the relationship between the degree of oxidization and strength degradation. In addition, the change of oxidation rate by graphite oxidation degree characterization by burn-off (ratio of the oxidized graphite density to the original density) should be quantified because graphite strength degradation is followed by graphite density decrease, which highly affects oxidation rates and patterns. Because the density change is proportional to the internal pore surface area, they should be quantified in advance. In order to understand the above issues, the following experiments were performed: (1)Experiment on the fracture of the oxidized graphite and validation of the previous correlations, (2) Experiment on the change of oxidation rate using graphite density and data collection, (3) Measure the BET surface area of the graphite. The experiments were performed using H451 (Great Lakes Carbon Corporation) and IG-110 (Toyo Tanso Co., Ltd) graphite. The reason for the use of those graphite materials is because their chemical and mechanical characteristics are well identified by the previous investigations, and therefore it was convenient for us to access the published data, and to apply and validate our new methodologies. This paper presents preliminary results of compressive strength vs. burn-off and surface area density vs. burn-off, which can be used for the nuclear graphite selection for the NGNP.
Download or read book Handbook of Carbon Graphite Diamonds and Fullerenes written by Hugh O. Pierson and published by William Andrew. This book was released on 2012-12-02 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a review of the science and technology of the element carbon and its allotropes: graphite, diamond and the fullerenes. This field has expanded greatly in the last three decades stimulated by many major discoveries such as carbon fibers, low-pressure diamond, and the fullerenes. The need for such a book has been felt for some time. These carbon materials are very different in structure and properties. Some are very old (charcoal), others brand new (the fullerenes). They have different applications and markets and are produced by different segments of the industry.Few studies are available that attempt to review the entire field of carbon as a whole discipline. Moreover these studies were written several decades ago and a generally outdated since the development of the technology is moving very rapidly and scope of applications is constantly expanding and reaching into new fields such as aerospace, automotive, semiconductors, optics, and electronics. In this book the author provides a valuable, up-to-date account of both the newer and traditional forms of carbon, both naturally occurring and man-made. This volume will be a valuable resource for both specialists in, and occasional users of carbon materials.
Download or read book The Technological and Economic Future of Nuclear Power written by Reinhard Haas and published by Springer. This book was released on 2019-04-26 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book discusses the eroding economics of nuclear power for electricity generation as well as technical, legal, and political acceptance issues. The use of nuclear power for electricity generation is still a heavily disputed issue. Aside from technical risks, safety issues, and the unsolved problem of nuclear waste disposal, the economic performance is currently a major barrier. In recent years, the costs have skyrocketed especially in the European countries and North America. At the same time, the costs of alternatives such as photovoltaics and wind power have significantly decreased.
Download or read book Conference Papers Index written by and published by . This book was released on 1986 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monthly. Papers presented at recent meeting held all over the world by scientific, technical, engineering and medical groups. Sources are meeting programs and abstract publications, as well as questionnaires. Arranged under 17 subject sections, 7 of direct interest to the life scientist. Full programs of meetings listed under sections. Entry gives citation number, paper title, name, mailing address, and any ordering number assigned. Quarterly and annual indexes to subjects, authors, and programs (not available in monthly issues).
Download or read book Status of and Prospects for Gas cooled Reactors written by International Atomic Energy Agency and published by . This book was released on 1984 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
