Download or read book Neutron Spectra at Different High Flux Isotope Reactor HFIR Pressure Vessel Surveillance Locations written by and published by . This book was released on 1993 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project addresses the potential problem of radiation embrittlement of reactor pressure vessel (RPV) supports. Surveillance specimens irradiated at the High Flux Isotope Reactor (HFIR) at relatively low neutron flux levels (about 1.5E + 8 cm−2.s−1) and low temperatures (about 50°C) showed embrittlement more rapidly than expected. Commercial power reactors have similar flux levels and temperatures at the level vessel support structures. The purposes of this work are to provide the neutron fluence spectra data that are needed to evaluate previously measured mechanical property changes in the HFIR, to explain the discrepancies in neutron flux levels between the nickel dosimeters and two other dosimeters, neptunium and beryllium, and to address any questions or peculiarities of the HFIR reactor environment. The current work consists of neutron and gamma transport calculations, dosimetry measurements, and least-squares logarithmic adjustment to obtain the best estimates for the neutron spectra and the related neutron exposure parameters. The results indicate that the fission rates in neptunium-237 (Np-237) and uranium-238 (U-238) and the helium production rates in beryllium-9 (Be-9) are dominated by photo-induced reactions. The displacements per atom rate for iron (dpa/s) from gamma rays is five times higher than the dpa/s from neutrons. The neutron fluxes in key 7, position 5 do not show any significant gradient in the surveillance capsule, but key 4 and key 2 showed differences in magnitude as well as in the shape of the spectrum. The stainless steel monitor in the V-notch of the Charpy specimens of the surveillance capsules is adequate to determine the neutron flux above 1.0 MeV at the desired V-notch location. Simultaneous adjustment of neutron and gamma fluxes with the measurements has been demonstrated and should avoid future problems with photo-induced reactions.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactor Dosimetry State Of The Art 2008 Proceedings Of The 13th International Symposium written by Wim Voorbraak and published by World Scientific. This book was released on 2009-08-19 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives the state of the art in the field of reactor dosimetry as applied in nuclear power plants and research reactors. Surveillance programs are presented for nuclear power plants in Europe, including Russia and Ukraine, USA, Argentina and Korea. New cross-section measurements from most of the European, American and Japanese research reactors are reported. The latest developments in computer code development for radiation transport and shielding calculations, and radiation measurement techniques are also highlighted.
Download or read book Annual Report written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1996 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Discrete Ordinates Radiation Transport Calculations of Neutron Fluxes for Beginning of cycle at Several Pressure Vessel Surveillance Positions in the High Flux Isotope Reactor written by and published by . This book was released on 1993 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to determine improved thermal, epithermal, and fast fluxes and several responses at mechanical test surveillance location keys 2, 4, 5, and 7 of the pressure vessel of the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) for the beginning of the fuel cycle. The purpose of the research was to provide essential flux data in support of radiation embrittlement studies of the pressure vessel shell and beam tubes at some of the important locations.
Download or read book News Releases written by and published by . This book was released on 1993 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1994-07 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Radiation on Materials written by R. K. Nanstad and published by ASTM International. This book was released on 1999 with total page 1135 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutron Spectral Measurements in the Reactor Cavity of Two Commercial Pressurized Water Reactors written by Wesley William Sallee and published by . This book was released on 1983 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactor Dosimetry Proceedings Of The 9th International Symposium written by Hamid Ait Abderrahim and published by World Scientific. This book was released on 1998-03-25 with total page 959 pages. Available in PDF, EPUB and Kindle. Book excerpt: This symposium provided a forum for interchange of state-of-the-art techniques and databases and for standardization of radiation metrology.The proceedings are of value to anyone involved in reactor dosimetry, including researchers, manufacturers, and representatives from industry, utilities and regulatory agencies. The major topics treated are: reactor pressure vessel surveillance and plant life management; reactor dosimetry techniques; benchmarks; nuclear data; damage correlation and exposure parameters; experimental and calculational characterization of irradiation environments; dosimetry for research reactors and irradiation experiments.
Download or read book Analysis of Neutron Fluctuation Spectra in the Oak Ridge Research Reactor and the High Flux Isotope Reactor written by J. C. Robinson and published by . This book was released on 1967 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Calculation Investigations of the Space Energy Neutron and Photon Distribution in the Vicinity of Reactor Pressure Vessel and Surveillance Specimen Box of New Type in the WWER 1000 Mock Up written by B. Ošmera and published by . This book was released on 2006 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The radiation field parameters in the vicinity of new type of WWER-1000 surveillance specimens boxes and in RPV simulator have been investigated in the WWER-1000 Mock-up in the reactor LR-0. The neutron and photon spectra have been measured with stilbene cylindrical crystals in the energy range approximately from 0.5 MeV to 10 MeV. The experimental values of integral neutron field parameters (attenuations of integral neutron flux densities between different points of mock-up as well as the spectral indices, i.e., ratios of integral neutron flux densities with different thresholds) were obtained also. The mock-up (LR-0 reactor) power monitoring during measurements was carried out with two fission chambers, one fixed, one moveable axially, so that four orders in power were covered. The experimental data (spectra, attenuation factors, and spectral indices) have been compared with the calculation results. The sensitivity to parameters of calculation model and method was evaluated also.
Download or read book Attenuation of Radiation Damage and Neutron Field in Reactor Pressure Vessel Wall written by Ladislav Zerola and published by . This book was released on 2006 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the paper the large-scale irradiation experiment is described. It is aimed at the experimental assessment of the effect of reactor pressure vessel wall on neutron flux, neutron energy spectrum as well as irradiation embrittlement through the vessel wall. The experiment was realized within the IAEA Technical cooperation project. The irradiation was performed in the RIAR, Dimitrovgrad, Russian Federation, under the coordination by the Nuclear Research Institute Rez plc, Rez, Czech Republic. Mechanical testing and neutron dosimetry will be performed in both organizations with the larger part in the coordinating institute.
Download or read book Three dimensional Calculations of Neutron Streaming in the Beam Tubes of the ORNL HFIR High Flux Isotope Reactor Reactor written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The streaming of neutrons through the beam tubes in High Flux Isotope Reactor at Oak Ridge National Laboratory has resulted in a reduction of the fracture toughness of the reactor vessel. As a result, an evaluation of vessel integrity was undertaken in order to determine if the reactor can be operated again. As a part of this evaluation, three-dimensional neutron transport calculations were performed to obtain fluxes at points of interest in the wall of the vessel. By comparing the calculated and measured activation of dosimetry specimens from the vessel surveillance program, it was determined that the calculated flux shape was satisfactory to transpose the surveillance data to the locations in the vessel. A bias factor was applied to correct for the average C/E ratio of 0.69. 8 refs., 7 figs., 3 tabs.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1974 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
