Download or read book Analytical Applications for Delayed Neutrons written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes.
Download or read book Analytical Applications of Delayed Neutron Emission in Fissionable Elements written by Saadia Amiel and published by . This book was released on 1961 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Activation Analysis written by S. Amiel and published by Elsevier. This book was released on 2012-12-02 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies in Analytical Chemistry, 3: Nondestructive Activation Analysis focuses on the reactions, principles, methodologies, and approaches involved in nondestructive activation analysis. The selection first offers information on irradiation, measurement and techniques, and manual and computerized data processing in activation analysis. Discussions focus on result computation with Nal(Tl) and Ge(Li) data, analysis of gamma-ray spectra, X-ray, spectrometry, neutron counting in activation analysis, neutron sources, and measurement of very short-lived nuclides. The book then examines applications, including biomedical sciences, geo- and cosmochemistry, applications of trace element analysis to studies of the atmospheric environment, and high purity materials, standards, and reference materials. The text discusses the applications of nondestructive activation analysis to archaeology, industry, and forensics. The selection is a vital reference for researchers wanting to explore nondestructive activation analysis.
Download or read book A Comprehensive Study of the Neutron Activation Analysis of Uranium by Delayed neutron Counting written by F. F. Dyer and published by . This book was released on 1962 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Delayed Neutron Analysis Its Application in the Determination of Uranium and Therium in the By product of the Tin Mining Industry written by Zulkafli Ghazali and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of the Delayed Neutrons written by and published by . This book was released on 1947 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Technologies and Applications of Neutron Activation Analysis written by Lylia Alghem Hamidatou and published by . This book was released on 2019-04-17 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the advanced technologies and applications of neutron activation analysis (NAA). It discusses the latest developments influencing the performance and utility of different NAA techniques across wide areas of applications: nuclear technology, industry, medicine, clinical investigations, biology, geochemistry, soil contamination, waste management, diet, lifestyle and health, cosmology, archeology, forensic science, etc. The overall goal of the book is to promote innovation and development of NAA techniques, technologies, and nuclear culture by presenting high-quality chapters with numerous results at both national and international levels. The book will serve as a source for graduate and postgraduate students in nuclear sciences and applications and nuclear analytical techniques, experienced practitioners who want to implement or use other varieties of NAA, professional technicians and analysts, users of NAA, and other stakeholders who wish to better understand NAA techniques.
Download or read book The Determination of the Ranges of the Fission Fragments Emitting Delayed Neutrons Chemical Identification of the 4 51s Delayed Neutron Activity written by N. Sugarman and published by . This book was released on 1946 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutron Diffusion written by S. Chakraverty and published by CRC Press. This book was released on 2017-04-21 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is designed for a systematic understanding of nuclear diffusion theory along with fuzzy/interval/stochastic uncertainty. This will serve to be a benchmark book for graduate & postgraduate students, teachers, engineers and researchers throughout the globe. In view of the recent developments in nuclear engineering, it is important to study the basic concepts of this field along with the diffusion processes for nuclear reactor design. Also, it is known that uncertainty is a must in every field of engineering and science and, in particular, with regards to nuclear-related problems. As such, one may need to understand the nuclear diffusion principles/theories corresponding with reliable and efficient techniques for the solution of such uncertain problems. Accordingly this book aims to provide a new direction for readers with basic concepts of reactor physics as well as neutron diffusion theory. On the other hand, it also includes uncertainty (in terms of fuzzy, interval, stochastic) and their applications in nuclear diffusion problems in a systematic manner, along with recent developments. The underlying concepts of the presented methods in this book may very well be used/extended to various other engineering disciplines viz. electronics, marine, chemical, mining engineering and other sciences such as physics, chemistry, biotechnology etc. This book then can be widely applied wherever one wants to model their physical problems in terms of non-probabilistic methods viz. fuzzy/stochastic for the true essence of the real problems.
Download or read book U S Geological Survey Bulletin written by and published by . This book was released on 1987 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Delayed Neutron Counting for Uranium Analysis in Biological Tissue and Its Application to a Pharmacokinetic Study in Weanling Rats written by Philip D. Nelson and published by . This book was released on 1984 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Delayed neutron counting (DNC) is a variation of neutron activation analysis applicable only to fissionable elements. Briefly, it involves exposing a sample to the neutron flux in a reactor to induce fission, then quickly retrieving the sample to count the delayed fission neutrons emitted. These are proportional to the amount of the fissionable element in the sample. This technique has been used for over two decades to assay uranium in geological and water samples. I investigated its applicability to biological tissues, specifically soft tissues and bones. Only the simplest sample preparation was required. Samples needed only to be freeze dried, weighed and encapsulated in polyvials before activation. This allowed rapid preparation of large numbers of samples at low cost (about half that of conventional chemical analyses). The minimum level of detection (MLD) for 1/2 gram samples was about 10 nanograms for natural uranium. Precision was comparable to values attained for other methods of uranium analysis. Accuracy was determined by using a relative accuracy. Prepared standard solutions were analyzed for uranium content by an outside laboratory and then all counting data were compared to these values. The effects on precision and accuracy of a variety of factors in sample preparation, activation, and neutron counting were evaluated. DNC appears to have substantial advantages for uranium analysis over conventional methods, while achieving similar precision, accuracy, and MLD. The DNC method was used to study the uptake, distribution, and clearance of an acute dose of uranium in weanling rats. The dose was administered by gavage. Animals were killed and various tissues were collected at several times post gavage. The absorption of uranium in the GI tract occurred primarily in the stomach within 15 minutes, and appeared to be dependent upon the acidity of the stomach contents. Uranium absorbed from the GI tract entered the blood and deposited in the skeleton. Uptake and loss in the skeleton followed two patterns. A transitory uptake was observed in the skull, while a slower, longer term uptake associated with bone growth or degree of bone mineralization was observed in the remainder of the skeleton. Uptake and loss in the kidney followed a similar pattern as observed for the skeleton (excluding the skull). In addition, the relative distribution of uranium in the skeleton, i.e., the fractional burdens of the individual bones of the skeleton, appeared to be independent of time post gavage, age, route of administration, and sex.
Download or read book The Effect of Delayed Neutrons and Detector Dead time in Feynman Distribution Analysis written by Mathieu Brener and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I have explored the effect of delayed neutrons on neutron chains in a sub-critical nuclear system. Every fission has an approximately 0.7% chance of creating a delayed neutron that will go on to cause another fission. My hypothesis was that in systems with a very high sub-critical multiplication, there will be enough delayed neutrons created that they will in effect become a stronger starting neutron source than the original source. I used a point Monte-Carlo style simulation of sub-critical neutron chains to explore the physics of neutron chains. The simulation was designed to keep the same assumptions behind the Hage-Cifarelli derivation and Prasad-Snyderman formulation, to preserve the statistical variations in the list-mode data found in a physical experiment, and to be as simple as possible while maintaining accuracy. I present this method and benchmark it against both measured data and a theoretical model. I also use the model to simulate a Feynman Beta curve and 1/M approach-to-criticality experiments. I modified the simulation to take into account delayed neutrons and found that delayed neutrons have no measurable effect on a sub-critical systems for subcritical multiplication (M) less then 200. I wrote an algorithm to take into account detector dead-time with multiple detectors and found that increasing the number of detectors is the only effective method of compensating for dead-time effects. I investigated the minimum number of events needed for the analysis methods to produce accurate results and found that, for low values of M, there are statistical variations of the calculated multiplicity that will produce inaccurate results. For high values of M, the statistical variation is low, but an insufficient number of events will produce M-values that are inaccurately low.
Download or read book Use of One Delayed neutron Precursor Group in Transient Analysis PWR BWR written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In most reactor dynamics calculations six groups of delayed-neutron precursors are usually accounted for. However, under certain circumstances it may be advantageous to simplify the calculation and utilize a single delayed-neutron group. The motivation for going to one precursor group is economy. For LWR transient codes that use point kinetics the equations are solved very rapidly and six precursor groups should always be used. However, codes with spatially dependent neutron kinetics are very long running and the use of one precursor group may save computer costs and not impair the accuracy of the results significantly. Furthermore, in some codes, the elimation of five presursor groups makes additional memory available which may be used to give a net increase in the accuracy of the calculations, e.g., by allowing for an increase in mesh density. In order to use one delayed neutron precursor group it is necessary to derive a single decay constant, 6lambda-, which, along with the total (or one group) delayed neutron fraction .beta. = .sigma./sub i = 1/.beta./sub i/, will adequately describe the transeint precursor behavior. The present summary explains how a recommendation for lambda- was derived.
Download or read book Automated uranium analysis by delayed neutron counting written by H. Kunzendorf and published by . This book was released on 1980 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Delayed Neutron Analysis written by Zulkafli Ghazali and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A COMPREHENSIVE STUDY OF THE NEUTRON ACTIVATION ANALYSIS OF URANIUM BY DELAYED NEUTRON COUNTING written by and published by . This book was released on 1962 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The method of neutron activation analysis of U by delayed-neutron counting was investigated in order to ascertain if the method would be suitable for routine application to such analyses. It was shown that the method can be used extensively and routinely for the determination of U. Emphasis was placed on the determination of U in the types of sample materials encountered in nuclear technology. Determinations of U were made on such materials as ores, granite, sea sediments, biological tissue, graphite, and metal alloys. The method is based upon the fact that delayed neutrons are emitted from fission products from the interaction of neutrons with U/sup 235/. Since the U/sup 235/ component of U undergoes most of the fissions when a sample is in a neutron flux, the method is predominately one for the determination of U/sup 235/. The total U in a sample or the isotopic composition of the U in a sample can be determined provided there is a prior knowledge of one of these quantities. The U/sup 235/ content of a test sample is obtained by comparing its delayed-neutron count to that obtained with a comparator sample containing a known quantity of U/sup 235/. (auth).
Download or read book Energy Research Abstracts written by and published by . This book was released on 1984 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
