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

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iBAHC35-A35 GROUP CROSS-SECTION LIBRARY WITH P3-ANISOTROPIC
SCATTERING MATRICES AND RESONANCE SELF-SHIEIDING FACTORS*, S.B.
Garg and Amar Sinha, Neutron Physics Division, Bhabha Atomio
Research Centre, Trombay, Bomb-/ 400 085
Multigroup cross-sections are the basic input constants
to study the neutronio behaviour of reactor assemblies* These
basic-constants should account for the effects of different
temperatures and material compositions in the various assembly
regions and should represent well the anisotropio behaviour of
the scattering phenomena. To meet these requirements a 35
group crose-section set, called BAHC35, has been derived from
the basic ENDP/B-IT cross-section library for 57 elements. P3anisotropic
scattering matrices and resonance self-shielding
factors have also been evaluated and included in this library.
Resonance self-shielding factors are given at 3O0°K, 900°K and
21O0°K for a variety of dilution constants. At any intermediate
temperature and dilution the self-shielding factors are evaluated
by appropriate interpolation schemes.
This cross-section library has produced close agreements
in the measured and calcuated multiplication constants of a few
selected fast critical assemblies representing large oxide and
carbide fuelled uranium and plutonium based systems. The reason
for selecting large assemblies is that the resonanoe selfshielding
factors play a dominant role in determining their
physics characteristics.
The seleoted assemblies Include 2PPR2, ZPR-3-48, ZPR-3-53,
ZPR-6-6A, ZPR-6-7, ZPR-9-31 and ZEBRA2 and are amongst those
recommended by the US Nuclear Data Evaluation Working group for
testing the accuracy of cross-sections.
BARC35 library is well suited for the safety and neutronlcs
studies of thermal, fast or fusion-fission hybrid systems*
The library is available on request.
* Issued as a BARC Report BARO-1222 (1934)