Within-Pin Reaction Rate Distributions: CASMO-4 and HELIOS Compared Against Tomographic Measurements at the PROTEUS Reactor
- Paul Scherrer Institute (Switzerland)
In the framework of the LWR-PROTEUS project - an extended validation program for advanced light water reactor core analysis tools conducted at the Paul Scherrer Institute - the radial, internal variations of the total fission rate (F{sub tot}) and the capture rate in {sup 238}U (C{sub 8}) have been calculated for zero-burnup pins of a Westinghouse SVEA-96+ boiling water reactor fuel assembly using two codes, namely, CASMO-4 and HELIOS. While F{sub tot} distributions predicted by CASMO-4 and HELIOS are in good agreement, C{sub 8} distributions show significant inconsistencies (20 to 30%). The calculations are compared with experimental results obtained using single photon emission computerized tomography for several SVEA-96+ pins irradiated in the zero-power reactor PROTEUS. The comparisons confirm the predicted shape of the F{sub tot} distributions within UO{sub 2} pins and clearly indicate that HELIOS within-pin predictions for C{sub 8} are more reliable than CASMO-4 results. This is important for the derivation of gamma-ray self-absorption corrections when pin-integrated reaction rates are to be determined using the gamma-scanning technique. Thus, the use of CASMO-4-type within-pin distributions would lead to 3 to 4% discrepancies in the absolute, self-absorption-corrected pin-integrated values deduced for C{sub 8} and hence for C{sub 8}/F{sub tot}. For relative C{sub 8} distributions, the discrepancy would be much smaller, namely, up to {approx}1% if pins containing a burnable absorber are involved.
- OSTI ID:
- 20808432
- Journal Information:
- Nuclear Science and Engineering, Vol. 150, Issue 1; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 0029-5639
- Country of Publication:
- United States
- Language:
- English
Similar Records
Neutronics Investigations for the Lower Part of a Westinghouse SVEA-96+ Assembly
Experimental validation of 3D reconstructed pin-power distributions in full-scale BWR fuel assemblies with partial length rods