NEA-0823 NEUPAC.

1. NAME OR DESIGNATION OF PROGRAM:  NEUPAC. Neutron Unfolding Code Package.

3. DESCRIPTION OF PROBLEM OR FUNCTION

The code is able to determine the integral quantities and their sensitivities, together with an estimate of the unfolded spectrum and integral quantities. The code  also performs a chi-square test of the input/output data, and contains many options for the calculational routines.

4. METHOD OF SOLUTION

The code is based on the J1-type unfolding method, and the estimated neutron flux spectrum is obtained as its solution.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The maximum number of energy groups used for unfolding is 620. The maximum number of reaction rates and the window functions given as input is 20. The total storage requirement depends on the amount of input data.

6. TYPICAL RUNNING TIME

4.8 sec CPU time are needed for a 7 reaction  and 25 energy group calculation.

NEA-DB executed the test case included in this package  on an IBM 3084Q computer in 0.27 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

NEUPAC-ADJUST - performs neutron cross section adjustment using the J1-method with the standard neutron spectra.

10. REFERENCES

- M. Nakazawa and A. Sekiguchi:
  New Data Processing Technique for Reactor Neutron Dosimetry,
  NUREG-CP-0004 (Vol. 3), 1423-33 (1977).
  Proceedings of the 2nd ASTM-Euratom Symposium on Reactor Dosi-
  metry (Palo Alto, 1977).
- N. Nakazawa and A. Sekiguchi:
  Several Applications of J1-Unfolding Method of Multi-Foil Data to
  Reactor Neutron Dosimetry, 3rd ASTM-Euratom Symposium on Reactor
  Dosimetry (Ispra, 1979).

- M. Sasaki and M. Nakazawa:
  Production of Analysis Code for "JOYO" Dosimetry Experiment,
  User's Manual of Neutron Unfolding Code Package "NEUPAC".
  PNC N941 80-192Tr  (January 1981).

11. MACHINE REQUIREMENTS

The above problem can be run in as little as 784 kbytes of core memory.

To execute the test case included in this package on an IBM 3084Q computer, 1776K bytes of main storage are required.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  OS/Edition 4 for  FACOM.

VS2 03.8 (IBM 3084Q).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

          Makoto Sasaki
          Mitsubishi Atomic Power Ind., Inc.
          Nuclear Development Center
          1-279, Kitabukuro-cho, Omiya-shi
          Saitama-ken, 330 Japan

          Masaharu Nakazawa
          Nuclear Engineering Research Lab.
          Faculty of Engineering
          University of Tokyo
          2-22 Shirakata-shirane, Tokai-mura
          Naka-gun, Ibaraki-ken, 319-11 Japan

File name	File description	Records
NEA0823_01.001	This information file	56
NEA0823_01.002	NEUPAC source program	7551
NEA0823_01.003	JCL to compile and link	89
NEA0823_01.004	JCL to execute	11
NEA0823_01.005	Sample Input	628
NEA0823_01.006	Sample Printed Output	3649