Download or read book A Review on the Modeling of Fission Chambers written by Zoairia Lyric and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fission chambers are ideal neutron flux surveillance instruments to ensure nuclear reactor control and safety. They can provide online, in-core, real-time measurements covering the dynamic range of neutron flux including pulse, Campbell, and current mode over decades of reactor operation cycles. The first patented fission chamber was developed by Baer et al. in 1957. It was a cylindrical assembly thermal fission counter having sensitivity of 0.7 count/neutron cm−2 for a background measurement of 5 counts/second with ability to operate at a temperature range of 20-80 oC [3]. Since then, fission chamber technology was developed to come up with miniature and sub-miniature dimensions withstanding high irradiation and high temperature environment making them suitable for in-core online diagnosis. Since the introduction of high temperature fission chamber technology starting in the 1970's, the need of the advancement in modeling of the fission chambers to improve their performance has become important. The development of modeling depends upon the understanding and consideration of underlying physics of these detectors. The validation of modeling of fission chambers will need the quantification of uncertainty introduced at every stage from neutron-deposit interaction to signal shaping. Based on this objective, a detailed review was performed on fission chamber modeling and simulation covering neutron flux self-shielding, fissile deposit evolution, fission product emission, auto-absorption, electron-ion pair creation, charge recombination and avalanche, space charge effect, charge transport, propagation of electronic pulse and pulse shaping. The analytical methods, algorithmic treatments, simulation, and computation codes used so far in case of modeling different aspects of fission chambers were reviewed. Along with the numerical methods and computer codes for simulating electron drift and charge transport for the usual gas chamber detectors, the use of several fissile material evolution techniques and computation codes were observed in case of fission chamber modeling. The use higher order statistics to handle fluctuation mode and to treat noisy data were observed. In recent years, fission chamber modeling made reasonable improvement in detail physics modeling. Several analytical methods like advanced statistics for Campbellng mode and electric field distortion due to space charge effect need to be incorporated in computation codes. More progress in the areas of evolution of gas behavior, consideration of Penning, recombination, and avalanche effect still needed.
Download or read book Initial Back to Back Fission Chamber Testing in ATRC written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.
Download or read book Method to Calibrate Fission Chambers in Campbelling Mode written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fission chambers are neutron detectors which are widely used to instrument experimental reactors such as material testing reactors or zero power reactors. In the presence of a high level mixed gamma and neutron flux, fission chambers can be operated in Campbelling mode (also known as 'fluctuation mode' or 'mean square voltage mode') to provide reliable and precise neutron related measurements. Fission chamber calibration in Campbelling mode (in terms of neutron flux) is usually done empirically using a calibrated reference detector. A major drawback of this method is that calibration measurements have to be performed in a neutron environment very similar to the one in which the calibrated detector will be used afterwards. What we propose here is a different approach based on characterizing the fission chamber response in terms of fission rate. This way, the detector calibration coefficient is independent from the neutron spectrum and can be determined prior to the experiment. The fissile deposit response to the neutron spectrum can then be assessed independently by other means (experimental or numerical). In this paper, the response of CEA made miniature fission chambers in Campbelling mode is studied. We use a theoretical model of the signal to calculate the calibration coefficient. Input parameters of the model come from statistical distribution of individual pulses. Supporting measurements have been made in the CEA Cadarache zero power reactor MINERVE. Results are compared to an empirical Campbelling mode calibration.
Download or read book K factor Fission Chamber written by John H. Larkins and published by . This book was released on 1950 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Development of a High Efficiency Small Volume Fission Chamber for Neutron Counting written by Calvin Thomas Swift and published by . This book was released on 1959 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Small Fission Chamber written by D. Barnes and published by . This book was released on 1957 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NEET Micro Pocket Fission Detector FY 2012 Status Report written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program has been initiated by the NEET program for developing and testing compact miniature fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package. When implemented, these sensors will significantly advance flux detection capabilities for irradiation tests in US Materials Test Reactors (MTRs). Ultimately, evaluations may lead to a more compact, more accurate, and longer lifetime flux sensor for critical mock-ups, high performance reactors and commercial nuclear power plants. Deployment of Micro-Pocket Fission Detectors (MPFDs) in US DOE-NE program irradiation tests will address several challenges: Current fission chamber technologies do not offer the ability to measure fast flux, thermal flux and temperature within a single compact probe, MPFDs offer this option. MPFD construction is very different then current fission chamber construction; the use of high temperature materials allow MPFDs to be specifically tailored to survive harsh conditions in typical high performance MTR irradiation tests. New high-fidelity reactor physics codes will need a small, accurate, multipurpose in-core sensor to validate the codes without perturbing the validation experiment; MPFDs fill this requirement. MPFDs can be built with variable sensitivities to survive the lifetime of an experiment or fuel assembly in some MTRs; allowing for more efficient and cost effective power monitoring. The small size of the MPFDs allows multiple sensors to be simultaneously deployed; obtaining data required to visualize the reactor flux and temperature profiles. This report summarizes the research progress for year 1 of this 3 year project. An updated design of the MPFD has been developed, materials and tools to support the new design have been procured, construction methods to support the new design have been initiated at INL's HTTL and KSU's SMART Laboratory, plating methods are being updated at KSU, new detector electronics have been designed, built and tested at KSU. In addition, a project meeting was held at KSU and a detector evaluation plan has been initiated between INL and KSU. Once NEET program evaluations are completed, the final MPFD will be deployed in MTR irradiations, enabling DOE-NE programs evaluating the performance of candidate new fuels and materials to better characterize irradiation test conditions.
Download or read book A Fission Chamber for Operation at 850C written by United Kingdom Atomic Energy Authority. Research Group. Atomic Energy Establishment. High Temperature Research Division and published by . This book was released on 1960 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fission Chamber for Operation at 850 C written by D. Barnes and published by . This book was released on 1960 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report written by Instytut Badań Jądrowych (Poland) and published by . This book was released on 1964 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Capacity Giant Fission Ionization Chamber written by J. DeJuren and published by . This book was released on 1951 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ionization chamber for the detection of neutrons with an energy greater than 50 Mev is described. A special electrode and circuit arrangement is employed to avoid high capacitance with large plate area.
Download or read book Fission Chamber Assembly and Matching Preamplifier written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The preamplifier for the wide-range counting channel at the High Flux Isotope Reactor was redesigned. This new design incorporates current state-of-the-art components as replacements for the obsolete components of the earlier design. To accommodate the new design, a test and maintenance manual was prepared for use by qualified technicians and field engineers. The test procedures described herein do not require special test equipment and have been successfully applied to the prototype design.
Download or read book Design and Construction of a Parallel Plate Fission Chamber written by Edward A. Straker and published by . This book was released on 1962 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactor Dosimetry in the 21st Century written by Jan Wagemans and published by World Scientific. This book was released on 2003 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the state of the art in reactor dosimetry as applied to nuclear power plants and to high performance research reactors, accelerator-driven systems and spallation sources. The reader will also find the latest advances in computer code development for radiation transport and shielding. In addition, the book focuses on radiation measurement techniques.
Download or read book NEET Enhanced Micro Pocket Fission Detector for High Temperature Reactors FY15 Status Report written by and published by . This book was released on 2015 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new project, that is a collaboration between the Idaho National Laboratory (INL), the Kansas State University (KSU), and the French Atomic Energy Agency, Commissariat à l'Énergie Atomique et aux Energies Alternatives, (CEA), has been initiated by the Nuclear Energy Enabling Technologies (NEET) Advanced Sensors and Instrumentation (ASI) program for developing and testing High Temperature Micro-Pocket Fission Detectors (HT MPFD), which are compact fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package for temperatures up to 800 °C. The MPFD technology utilizes a small, multi-purpose, robust, in-core parallel plate fission chamber and thermocouple. As discussed within this report, the small size, variable sensitivity, and increased accuracy of the MPFD technology represent a revolutionary improvement over current methods used to support irradiations in US Material Test Reactors (MTRs). Previous research conducted through NEET ASI1-3 has shown that the MPFD technology could be made robust and was successfully tested in a reactor core. This new project will further the MPFD technology for higher temperature regimes and other reactor applications by developing a HT MPFD suitable for temperatures up to 800 °C. This report summarizes the research progress for year one of this three year project. Highlights from research accomplishments include: A joint collaboration was initiated between INL, KSU, and CEA. Note that CEA is participating at their own expense because of interest in this unique new sensor. An updated HT MPFD design was developed. New high temperature-compatible materials for HT MPFD construction were procured. Construction methods to support the new design were evaluated at INL. Laboratory evaluations of HT MPFD were initiated. Electrical contact and fissile material plating has been performed at KSU. Updated detector electronics are undergoing evaluations at KSU. A project meeting was held at KSU to discuss the roles and responsibilities between INL and KSU for development of the HT MPFDs. Provide input to various irradiation programs for installation of the MPFD technology in irradiation tests. As documented in this report, FY15 funding has allowed the project to meet year one planned accomplishments to develop a HT MPFD that offers US MTR users enhanced capabilities for real-time measurement of flux and temperature with a single detector. In addition, the accomplishments of this project have attracted funding from other Department of Energy Office of Nuclear Energy (DOE-NE) programs for additional applications. The work in those programs will build on current activities completed in this NEETASI HT MPFD project, but the MPFD will be specifically tailored to meet their program needs.
Download or read book NUREG CR written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1980 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Investigation of Some Sources of Error in the Measurement of Absolute Fission Ratios in Fast Reactors written by W. G. Davey and published by . This book was released on 1961 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements in AFSR of the changes in some fission ratios which result from the proximity of relatively small quantities of steel and polyethylene are described. The results show that some of the measurements with the Kirn absolute fission chambers in ZPR III are probably in error by several percent.
