1. NAME AND TITLE OF DATA LIBRARY

COVFILS-2: Neutron Data and Covariances for Sensitivity and Uncertainty Analysis.

2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS

BOXR: Reconstruct Complete Matrix from Compressed Format.

3. CONTRIBUTOR

Los Alamos National Laboratory, Los Alamos, New Mexico.

4. HISTORICAL BACKGROUND AND INFORMATION

Like the earlier DLC-091/COVFILS 30-group library, COVFILS-2 was produced using modules of the PSR-171/NJOY nuclear data processing system. The new library includes several additional nuclides.

5. APPLICATION OF THE DATA

COVFILS-2 is a library of multigroup neutron cross sections, scattering matrices and covariances. This 74-group library is primarily intended for use in the sensitivity and uncertainty analysis of fusion integral experiments and fusion reactor systems.

6. SOURCE AND SCOPE OF DATA

COVFILS-2 is largely based on data evaluations from the ENDF/B-V library, although some minor corrections and improvements were incorporated. In cases where the covariance evaluation is missing (as in the case of Be) or judged to be inadequate, private Los Alamos evaluations, such as LA-7932-MS, are employed. The COVFILS-2 group structure was chosen to give good energy resolution at high energies. It is a subset of the Los Alamos 187-group structure used in MATXS8. The groups are ordered in ENDF/B order (low-to-high) for all vector data and for the covariance matrices. Full (P0-P3) transfer matrices in normal high-to-low order for all scattering reactions present in the library are also included. The elements included are:

H, ⁶Li, ⁷Li, Be, C, N, O, Na, Al, Si, Cr, Fe, Ni, Pb.

7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM

Both to save space and to simplify the application of these data to uncertainty analyses, redundant reactions are omitted from COVFILS-2. BOXR reads from Fortran unit 20 those portions of the library which have been selected by the user and writes the complete matrix to Fortran unit 21. The input to reconstruct the entire library, which occupies 970,000 lines, is included in file 4 of the package.

8. DATA FORMAT AND COMPUTER

Card images; Cray, CDC, IBM.

9. TYPICAL RUNNING TIME

The sample problem for only one material took 14 seconds on the IBM 3033 under the MVS operating system.

10. REFERENCES

D. W. Muir, "COVFILS-2: Neutron Data and Covariances for Sensitivity and Uncertainty Analysis," Fusion Technology 10(3), Part 2B, pp. 1461-1465 (November 1986).

D. W. Muir, "The Evaluation and Application of Redundant- Cross-Section Covariances," LA-UR-86-3786-Rev (November 1986).

J. W. Davidson, D. J. Dudziak, D. W. Muir, J. Stepanek and C. E. Higgs, "Recent Joint Developments in Cross-Section Uncertainty Analysis at Los Alamos and EIR," LA-UR-87-219 (January 1987).

11. CONTENTS OF LIBRARY

Included are the referenced document and one (1.2MB) DOS diskette which contains the data, Fortran retrieval source, sample input and output.

12. DATE OF ABSTRACT

May 1988.