Degree Type

Dissertation

Date of Award

1987

Degree Name

Doctor of Philosophy

Department

Nuclear Engineering

Abstract

A concept of local/global components, based on the frequency dependent detector adjoint function, and a nodalization technique was utilized in the development of one- and two- dimensional computer codes to calculate the response of a detector to a vibrating absorber in reactor cores. The frequency dependent detector adjoint functions presented by complex equations were expanded into real and imaginary parts. In the nodalization technique, the flux is expanded into polynomials about the center point of each node;The phase angles and the magnitudes of the two-energy group detector adjoint functions were calculated for a neutron detector located in the middle of the south core tank of the Iowa State University UTR-10 reactor using a one-dimensional computer code. Results were compared with the exact analytical solution and were found to be within 2% of the values obtained from the analytical solution;Using a two-dimensional computer code, the phase angle and the magnitude of the one-energy group detector adjoint function was calculated for a detector located in the center of a 200 cm x 200 cm reactor. Results were within 3% of the values obtained from the analytical solution and the computer code EXTERMINATOR. The phase angle varied from 0.1 degrees to 0.4 degrees compared to 0.2 degrees calculated using the point reactor zero power transfer function;The phase angle and the magnitude of the two-energy group detector adjoint function were calculated for the detector located in the center of a 60 cm x 60 cm reactor. The results follow the expected behavior of the Green's functions. The phase angle for this two-energy group model was also found to vary from 0.2 degrees to 0.4 degrees.

DOI

https://doi.org/10.31274/rtd-180813-8621

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Soli T. Khericha

Language

en

Proquest ID

AAI8716782

File Format

application/pdf

File Size

99 pages

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