Abstract: In thermal reactors, the spatial change of thermal neutron flux (TNF) is significant. A non-uniform TNF distribution is unfavorable, since it results in non-uniform burn-up of the fuel rods. This problem may be eased by using a reflector surrounding the reactor. Neutron Activation Analysis (NAA) have been used to measure TNF. The activation cross section of dysprosium is very large and the activity of such material is proportional to the TNF. Therefore, the induced activity values can be directly used to represent the relative thermal flux distribution. Furthermore identical experimental conditions (i.e.: identical volume of sample, identical irradiation time, etc.) are provided by using a wire sample. In this work a rare application of NAA is made by using a Dy-Al alloy wire. The wire is placed vertically in the core. Special arrangement is made in measuring the induced activity of the wire taken into account decay during measurement. Finally the so called refractor saving is approximated.
Keywords: thermal reactors, thermal neutron flux (TNF), Neutron Activation Analysis (NAA).
Title: Determination of Relative Axial Distribution of Thermal Neutron Flux Using Wire Neutron Activation Analysis
Author: A.A. Tashani
International Journal of Mathematics and Physical Sciences Research
ISSN 2348-5736 (Online)
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