IAEA0856 ZZ-BARC-27GRP.

1. NAME OR DESIGNATION OF PROGRAM:  ZZ-BARC-27GRP; ZZ-BARC-35-A.

3. DESCRIPTION OF PROBLEM OR FUNCTION


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BARC-27GRP
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  FORMAT: 1-DX

  NUMBER OF GROUPS: 27

NUCLIDES: U-235, U-238, Pu-239, Pu-240, Pu-241, C, O, H, Al, Si, Na, Mg, Cr, Fe, Ni, Mo

  ORIGIN: ENDF/B-IV

  WEIGHTING SPECTRUM: flux weighting proportional to 1/SIGMAT(u)
                      fission weighting plus 1/E spectrum


BARC-35-A
=========

  FORMAT: SPHINX, Fx2-TH

  NUMBER OF GROUPS: 35

NUCLIDES: Al, He, Si, H, Fe, O, C, Na, Li, B, Be, N, Ca, Mn, V, Mo, Pb, Pu, Gd, K, Sm, Dy, Lu, Nb, U, Cr, Ni, Th, Np, Am, Zr, Cd, Eu, Mg, Ta, Cm, F, Ti, W.

  ORIGIN: ENDF/B-IV

  WEIGHTING SPECTRUM: fission - 1/E - thermal Maxwellian

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27-group resonance self-shielding factors and infinite  diluted cross sections for U-235, U-238, Pu-239, Pu-240, Pu-241, C,  O, H, Al, Si, Na, Mg, Cr, Fe, Ni, Mo, generated by using the basic cross section and resonance parameter data from the ENDF/B-4 library.

4. METHOD OF SOLUTION

The 27-group constants were obtained by integrating the microscopic data over group intervals using a flux weighting proportional to 1/SIGMAT(u) and a fission plus 1/E spectrum. The standard ABBN group structure is used. The self-shielding factors were calculated for the following temperatures: 300, 900, 2100 (degrees Kelvin) and for potential scattering cross sections of 10000, 100, 10, 1 barns. A thermal group is also included.
For the 35-group library, resonance self-shielding factors are given at 300, 900, and 2100K for a variety of dilution constants. Group cross sections cover the energy range from 15 MeV to 0.005 eV and have been derived using Bondarenko flux approximation with a fission-1/E-thermal Maxwellian spectrum. The scattering cross sections have been represented by a P3 Legendre expansion.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME:

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

For the s7-group library, REAR and  editing program, distributed with the library. The SHIELD code based on ETOX was used to generate the library. The library format is the  one for the 1DX, a multipurpose, one-dimensional diffusion code for  generating fast reactor cross sections. - The entire 35-group library is contained in ISOTX and BRKOXS binary files and serve as inputs to SPHINX and FX2-TH. BCD listings of these two files for  transmission to different computer installations have been generated using the code BINX.

10. REFERENCES

- S.B. Garg:
"Multigroup Resonance Self-Shielding Factors and Cross Sections of    Main Reactor Elements"
  BARC-1002 (1979).
- S.B. Garg:
  "ENDF/B Based 27-Group Cross Sections for Some Rare-Earth and
  Concrete Elements"
  BARC-1000, INDC(IND)-25/GV (1979).

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

          S. B. Garg, S.O. (SE)
          E.R.P. Section
          BARC Trombay
          Bombay 400085
          India

File name	File description	Records
IAEA0856_01.001	ZZ-BARC-27GRP LIBRARY EBCDIC	4934
IAEA0856_01.002	REAR LIBRARY EDITING CODE F4	93
IAEA0856_01.003	REAR PRINTED OUTPUT	2220
IAEA0856_01.004	REAR JOB CONTROL LANGUAGE	51