NEA-0886 ZZ-AMPX-2/123.

1. NAME OR DESIGNATION OF PROGRAM:  ZZ-AMPX-2/123, ZZ-AMPX-2/219.

3. DESCRIPTION OF PROBLEM OR FUNCTION


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FORMAT: "data base" for subsequent collapsing into both fine and broad group data in various formats (working and/or weighted ANISN,  CCCC, etc.).

  NUMBER OF GROUPS: AMPX-2/123 -> 123 group structure
                    AMPX-2/219 -> 219 group structure

NUCLIDES: H, He, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, Cl, K, Ca,  Ti, V, Cr, Mn, Fe, Ni, Cu, Kr, Zirc, Mo, Tc, Rh, Ag, Cd, Xe, Sm, Eu, Gd, Dy, Cu, Ta, W, Re, Pb, Th, Pa, U, Np, Pu, Am, Cm.

  ORIGIN: ENDF/B-IV

WEIGHTING SPECTRUM: Most data were generated using a standard flux  over three energy ranges (fission - 1/E - Maxwellian) as point-to-fine-group cross sections  weighing function.

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The AMPX-2 P3 123- and 219- Group Neutron Cross-Section Master Interface Libraries may be considered as "data bases" for subsequent collapsing into both fine and broad group data in various formats (working and/or weighted ANISN, CCCC, etc.). The built-in 123 and 219 group structures have been used to process all  available data of ENDF/B-IV.

4. METHOD OF SOLUTION

The program AMPX-2 has been used to generate the data. By various executions of the module XLACS-2 (XLACS for bound H-1 in some materials) a number of independent libraries were  generated which then were combined using the AMPX-2 module AJAX.

Most data were generated using a standard flux over three energy ranges (fission - 1/E - Maxwellian) as point-to-fine-group cross sections weighing function. For some structural materials (e.g. Fe,  Cr,...) different master data sets were produced using a weighting function fission - 1/E sigmaT(SS-304) - Maxwellian, and the three parts of the spectrum were joined at properly selected energies.

For some nuclides (e.g. 238U and 240Pu) various master data sets have been produced which contain problem-dependent unresolved cross  sections characterized by the associated potential scattering cross  sections.

Some data sets contain P3 thermal scattering matrices, for which ENDF/B File 7 S(alpha,beta) data were used, e.g. MAT=1002 (H bound in H2O), MAT-1004 (O bound in P2O), etc.

Some materials have been generated with more than one thermal scattering matrix. Generally, the following temperatures were con- sidered: 450, 600, 750, and 900 K.

Also, high-temperature thermal scattering matrices have been generated. Where applicable (i.e. if the ENDF/B-IV evaluation con- tains resonance information File 2) Doppler broadening in the resolved and unresolved regions was calculated at the given temperature.

Where possible for resonance nuclides, the elastic scattering matrices were calculated using MT=2 data from a corresponding NPTXS  generated point cross-section library. The use of internally pro- duced elastic scattering data was bypassed in the XLACS-2 module.

Regarding the order of the produced thermal scattering matrices, both above-mentioned very light moderators (H and D) and light nuclides (i.e. A < 20) have P3 matrices.

For heavier nuclides, only P0 thermal scatteringmatrices were generated and normalized to the free-atom scattering cross sections  in the epithermal range (e.g. 238U); for nuclides with resonances in the thermal region (e.g. 235U, 240Pu), the thermal scattering matrices were normalized to the average values of the cross sections in the thermal range.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Only 123- and 219- group P3 calculations may be performed.

6. TYPICAL RUNNING TIME:

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

After appropriate further processing, the master data sets were used as library data in the following programs: ANISN, XSDRNM, KENO-4, and MORSE-CG for sufficiently large test cases.

10. REFERENCES:

- P.A. Landeyro, F. Siciliano and Tayyab Abbas:
  AMPX-2 123 Multigroup Neutronic Library Validation for Fuel
  Storage Pools. CNEN-RT/ING(80)17  (July 1980)
- F. Siciliano and T. Abbas:
  AMPX-2 123 Group Neutron Cross Section Library Validation for
  4.29WT.% U-235 Enriched UO2 Fuel Storage Under Water.
  CNEN-RT/ING(80)18  (September 1980)
- F. Siciliano and G. Lai:
  A Complete AMPX-2 123 Group Neutron Cross Section Library
  Production and Testing for Criticality Safety Calculations.
  CNEN-RT/ING(82)10  (April 1982)
- F. Siciliano and T. Abbas:
  AMPX-2 123 and 219 Group Neutron Cross Section Libraries
  Production and Validation for Criticality and Safety Studies.
  CNEN-RT/ING(80)20  (October 1980)
- M. Carotenuto, P.A. Landeyro, F. Siciliano and T. Abbas:
  Cross Section Validation for Fuel Storage Pools (Enrichment
  4.29wt%). Transaction ANS, Vol. 39 (Nov. 1981) pp. 530-531
- P.A. Landeyro, F. Siciliano and T. Abbas:
  Cross Section Validation for Fuel Storage Pools. Transaction ANS,
  (June 1981) pp. 361-362

11. MACHINE REQUIREMENTS:

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

F. Siciliano
ENEA
Comitato Nazionale per la Ricerca e per lo Sviluppo
dell'Energia Nucleare e delle Energie Alternative
Centro COMB Trisaia
75025 POLICORO (Matera), Italy

File name	File description	Records
NEA0886_03.001	INFORMATION FILE	74
NEA0886_03.002	AMPX-2 P3 123 GP. NEUTRON XSEC.MAST.INT.LIB.	462431
NEA0886_03.003	AIM MODULE LOG FILE, BCD-BINARY CONV.	320