Download or read book Neutron Flux Enhancement in the NRAD Reactor written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1987 a series of experiments were conducted at the NRAD reactor facility at Argonne National Laboratory - West (ANL-W) to investigate the possibility of increasing the thermal neutron content at the end of the reactor's east beam tube through the use of hydrogenous flux traps. It was desired to increase the thermal flux for a series of experiments to be performed in the east radiography cell, in which the enhanced flux was required in a relatively small volume. Hence, it was feasible to attempt to focus the cross section of the beam to a smaller area. Two flux traps were constructed from unborated polypropylene and tested to determine their effectiveness. Both traps were open to the entire cross-sectional area of the neutron beam (as it emerges from the wall and enters the beam room). The sides then converged such that at the end of the trap the beam would be 'focused' to a greater intensity. The differences in the two flux traps were primarily in length, and hence angle to the beam as the inlet and outlet cross-sectional areas were held constant. It should be noted that merely placing a slab of polypropylene in the beam will not yield significant multiplication as neutrons are primarily scattered away.

Download or read book Enhancement of the Thermal Neutron Flux in the Central Irradiation Facility of the Ohio State University Research Reactor written by Tze-Hore Howard Liu and published by . This book was released on 1979 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Flux Enhancement at LASREF written by and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The accelerator at the Los Alamos Meson Physics Facility produces a 1-mA beam of protons at an energy of 800 MeV. Since 1985, the Los Alamos Spallation Radiation Effects Facility (LASREF) has made use of the neutron flux that is generated as the incident protons interact with the nuclei in targets and a copper beam stop. A variety of basic and applied experiments in radiation damage and radiation effects have been completed. Recent studies indicate that the flux at LASREF can be increased by at least a factor of ten from the present level of about 5 E+17 m−2s−1. This requires changing the beam-stop material from Cu to W and optimizing the geometry of the beam-target interaction region. These studies are motivated by the need for a large volume, high energy, and high intensity neutron source in the development of materials for advanced energy concepts such as fusion reactors. 18 refs., 7 figs., 2 tabs.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Flux and Spectra Measurements in the Void Tank of the TRIGA Mark F Reactor written by K. C. Humpherys and published by . This book was released on 1962 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Minimum Critical Mass and Uniform Thermal Neutron Core Flux in an Experimental Reactor written by J. W. Morfitt and published by . This book was released on 1955 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Flux Distributions in Multiple Region Reactors written by S. Wallach and published by . This book was released on 1956 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report the problem is considered of determining neutron flux distributions in reactors consisting of discrete regions of substantially different nuclear properties. Starting with these equations the problem is considered of determining the flux in one of the energy groups given the spatial flux distribution of the next higher energy group. The problem is handled by converting the differential equation with source term to an integral equation; under appropriate conditions the integral equation may be solved by a numerical iterative procedure. The conditions under which this may be done are discussed and formulas are developed for placing bounds on the errors. In addition the technique of obtaining flux distributions in complicated configurations by additive and multiplicative superposition of flux distributions of simpler configurations is considered. Expressions are derived for estimating the errors made in using these methods. A number of simple examples are presented.

Download or read book Neutron Tissue Dose at Large Distances from an Elevated Unshielded Reactor written by Henry Aceto (Jr.) and published by . This book was released on 1963 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calculation of Fast neutron Flux Emerging from a Reactor Beamhole and Comparison with Experiment written by Harvey S. Bloomfield and published by . This book was released on 1967 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calculation of Thermal Neutron Fluxes in Primary Shields written by D. C. Anderson and published by . This book was released on 1959 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of a Flux Trap for Enhanced Thermal Neutron Production in a TRIGA Nuclear Reactor written by Ross Job Thompson and published by . This book was released on 1982 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Beam Enhancement in a Reactor Beam Port written by Henry Irving Crook and published by . This book was released on 1972 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectral Distribution and Flux Profiles of the NRAD Reactor written by David Graham McIntyre and published by . This book was released on 1980 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Beam Characterization at the Neutron Radiography Reactor NRAD written by and published by . This book was released on 1990 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Neutron Radiography Reactor (NRAD) is a 250-kW TRIGA Reactor operated by Argonne National Laboratory and is located near Idaho Falls, Idaho. The reactor and its facilities regarding radiography are detailed in another paper at this conference; this paper summarizes neutron flux measurements and calculations that have been performed to better understand and potentially improve the neutronics characteristics of the reactor.

Download or read book Application of High Speed Motion Neutron Radiography Techniques to Liquid Streams Injected Into a Pressurized Steel Chamber written by Dennis A. Tollefson and published by . This book was released on 1981 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high speed motion neutron radiography system has been developed at Oregon State University which is capable of taking high speed neutron radiographs of events which occur on the order of one to two milliseconds or more. This system was used previously to demonstrate the application of high speed motion neutron radiography techniques to two phase flow and to the burning of solid propellants. Results of this effort showed the burning patterns and relative distributions of the propellant and gases during the burning of these propellants. This system has been modified and the techniques adapted and further developed for the investigation of similar phenomena which occur with the burning of liquid propellants. The purpose of this thesis is to demonstrate the feasibility of using the new system and techniques for the investigation of liquid streams which were used to simulate the injection of liquid propellants into a pressurized steel chamber. Examples of the application of these new techniques to liquid streams injected into an unpressurized steel chamber are presented. The high speed system is capable of taking neutron radiography movies at frame rates up to about 11,000 frames per second, although about 5000 frames per second proved to be adequate for liquid streams. In order to use the high speed system for liquid streams several modifications and improvements were investigated, especially with regards to the synchronization method. A new fission probe method was developed which provided 100% reliability in the synchronization of events (over four orders of magnitude in time are covered) as compared with the 50% rate experienced with the previous time delay method. Other modifications include an improved method of masking of the object/event, an improved imaging system including a new image intensifier, new scintillator screens, and a new fiber optics coupling, and several methods of neutron flux enhancement. With the new system and techniques the position, distribution, and relative motion and sizes of liquid streams injected into a steel pipe or chamber could be measured. When applied to burning liquid propellants the distribution of the liquid and gas phases of the propellant could be determined. Applications of the current Oregon State University High Speed Motion Neutron Radiography Facility include the investigation of the flow dispersion patterns of liquid streams due to flow blockages or disruption objects; the investigation of diesel fuel injection mechanisms; and the investigation of a wide range of two phase flow situations, with particular emphasis on nuclear reactor related phenomena such as boiling boundaries, quench front motion, and boiling regimes.

Download or read book CALCULATED ENHANCEMENT OF THERMAL NEUTRON FLUX FROM A 252Cf SOURCE written by and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Benchmark Evaluation of the Neutron Radiography NRAD Reactor Upgraded LEU Fueled Core written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. The final upgraded core configuration with 64 fuel elements has been completed. Evaluated benchmark measurement data include criticality, control-rod worth measurements, shutdown margin, and excess reactivity. Dominant uncertainties in keff include the manganese content and impurities contained within the stainless steel cladding of the fuel and the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 nuclear data are approximately 1.4% greater than the benchmark model eigenvalue, supporting contemporary research regarding errors in the cross section data necessary to simulate TRIGA-type reactors. Uncertainties in reactivity effects measurements are estimated to be 1̃0% with calculations in agreement with benchmark experiment values within 2s. The completed benchmark evaluation de-tails are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Experiments (IRPhEP Handbook). Evaluation of the NRAD LEU cores containing 56, 60, and 62 fuel elements have also been completed, including analysis of their respective reactivity effects measurements; they are also available in the IRPhEP Handbook but will not be included in this summary paper.