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Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

Abstract

The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular `mock-up` reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent`s efficiency. Beyond this  More>>
Authors:
Publication Date:
Oct 22, 1997
Product Type:
Thesis/Dissertation
Report Number:
FRCEA-TH-725
Reference Number:
SCA: 220100; PA: AIX-30:044362; EDB-99:099388; SN: 99002152889
Resource Relation:
Other Information: DN: 128 refs.; TH: These Sciences; PBD: 22 Oct 1997
Subject:
22 NUCLEAR REACTOR TECHNOLOGY; A CODES; ACCURACY; BURNABLE POISONS; COMPUTERIZED SIMULATION; DATA COVARIANCES; HAFNIUM; INTEGRAL CROSS SECTIONS; LEAST SQUARE FIT; MATERIAL BUCKLING; MONTE CARLO METHOD; MULTI-PARAMETER ANALYSIS; NEUTRON TRANSPORT; NUCLEAR DATA COLLECTIONS; PERTURBATION THEORY; RESONANCE; RESONANCE INTEGRALS; T CODES
OSTI ID:
690290
Research Organizations:
CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Reacteurs; Universite de Provence, Aix-Marseille 1, (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
Other: ON: DE99635218; TRN: FR9904670044362
Availability:
INIS; OSTI as DE99635218
Submitting Site:
FRN
Size:
362 p.
Announcement Date:

Citation Formats

Palau, J M. Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium. France: N. p., 1997. Web.
Palau, J M. Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium. France.
Palau, J M. 1997. "Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium." France.
@misc{etde_690290,
title = {Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium}
author = {Palau, J M}
abstractNote = {The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular `mock-up` reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent`s efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author) 128 refs.}
place = {France}
year = {1997}
month = {Oct}
}