INDC(IND)-35G - IAEA Nuclear Data Services

- 45 -
A Critical Assessment of Multiy;.TOUp Nuclear Data for
Structural Elements
(S.Ganesan, M.M.Ramanadhan, V.Gopalakrishnan and R.S.
Keshavamurthy)
Our calculated values of central worths of structural
materials using the non-adjusted, ENDF/B-TV based, 1983 HRC
set and those using the 1969 adjusted French multigroup set
showed discrepancies ranging from + 20 to + 60$ in comparison
with experimental values in our 1 ' 2 analyses of selected fast
critical assemblies viz. ZPR-6-7, ZPR-9-31, ZPR-3-48 and
ZPR-3-56B. The Kgff of tho last assembly which has nickel
reflector showed an overprediction of 1.63$ when calculated
using the French set. One clear conclusion of the present
investigation is that the capture cross sections for Fe, Cr
and Ni in French set at HRC are definitely outdated and
incorrect. The modified French set in which the multigroup
sets for Fe, Cr and Ni alone were replaced in full by RRC
set gives a Keff close to unity.
Further, the currently reported discrepancies in
resonance parameters and measured cross sections in structural
elements are also being surveyed to identify problem areas
which need further attention*
1. S.Ganesan, M.M.Ramanadhan and V.Gopalakrishnan, 'Analysis
of ZPR-9 Assembly 31, the Advanced Fuels Program Carbide
Benchmark Assembly', RRC-61 (1983).
2. S.Ganesanet al., (unpublished work) 1983.
3. ENDF-202 Cross Section Evaluation Working Group Benchmark
Specifications, BNL 19302, Nov.1974» see also updates and
clarifications, from Philip M. Rose BNL, USA addressed to
S.Ganesan (May 1983).
ht J.L.Rowlands,et al., 'Convergence of Integral and Differen-
tial Croas Section Data for Structural Materials' Nucl.ar
Data for Science and Techn4o«y p.85 (1983). D. Reid.l
Publishing Company.