COV-15GROUP-2006: 15-Group Cross Section Covariance Matrix Library.

ANGELO-2/LAMBDA.

IAEA through the NEA Data Bank, Issy-les-Moulineaux, France.

COV-15GROUP-2006 is a 15-group cross section covariance matrix library presenting a general overview of the presently available data. The library includes the covariances from different sources and cross section evaluations: ENDF/B-V, /B-VI.8, JENDL-3.3, JEFF-3.0, IRDF-2002 and IAEA. The following nuclides are included: H-1, Li-6, Li-7, Be-9, B-10, C-12, N-14, O-16, F-19, Na-23, Al-27, Si-28, Si-nat, Cr-52, Mn-55, Fe-56, Fe-57, Ni-58, Zr-90, Pb-nat, Pb-206, -207, -208, Th-232, U-235, U-238, Np-237, Pu-239, Pu-240, Pu-241, Am-241. In this version the library file covfils2.lib was corrected (energy group structure was provided only for one isotope), as well as the corresponding test case outputs. The input files (original BOXER format covariance libraries and ANGELO inputs instructions) were included thus allowing to convert the covariance matrices to a user-defined energy group structure. Examples of output for the 15 group structure are provided. The code LAMBDA for verification of mathematical properties of the matrices (e. g. eigenvalues) is also included. This verification is highly recommended before using any covariance matrices.

Cross section data.

ENDF/B-V, /B-VI.8, JENDL-3.3, JEFF-3.0, IRDF-2002 and IAEA. The following nuclides are included: H-1, Li-6, Li-7, Be-9, B-10, C-12, N-14, O-16, F-19, Na-23, Al-27, Si-28, Si-nat, Cr-52, Mn-55, Fe-56, Fe-57, Ni-58, Zr-90, Pb-nat, Pb-206, -207, -208, Th-232, U-235, U-238, Np-237, Pu-239, Pu-240, Pu-241, Am-241.

The data are provided in the following 15-energy group structure [eV]:

1.0E-5

0.1

0.54

4.0

22.6033

454.0

2.03468E+3

9.11882E+3

24.7875E+3

67.3795E+3

183.156E+3

497.871E+3

1.35335E+6

2.23130E+6

6.06315E+6

19.6403E+6

The Fortran sources of the codes ANGELO-2 for the conversion of the matrices from the original to a user-defined energy group structure, and LAMBDA for the verification of the mathematical properties of the matrices, are given in the sub-directory \angelo. The input instructions can be found in '1p_manual.pdf'. After linking the codes make sure to modify the path in the ANGELO command procedure "angelo\angelo15.bat" according to the location of the executable module. Several sample inputs for the ANGELO code called 'MAT'-ang15.inp are available in the sub-directories \box of each evaluation. DOS command procedures called 'angelo.bat' are used to run the sample cases. The inputs contain at present the 15-energy group structure for the output matrices, which can be simply replaced by the one needed. The inputs are given for most, but not all the available matrices. The remaining matrices can be produced straightforward following the given examples and input instructions. The code LAMBDA uses similar inputs as the ANGELO code. An example of a DOS command procedure is given in the file '\eff3\box\lambda.bat'. The code ANGELO, for the interpolation of data from the original to a user defined energy structure is also included for the convenience of the users. An example of the transformation is provided for the H-1 covariance data. Note that the algorithm used in ANGELO is relatively simple; therefore the interpolations involving energy group structure which are very different from the original (e.g. large difference in the number of energy groups) may not be accurate.

PC with x86 processor (D00232MNYCP00).

Typically only a few seconds are needed on a PC to convert the matrices for one material to a new group structure.

**a. Documentation available with library**

I. Kodeli, “ZZ-COV-15GROUP-2006 – Covariance Data Review” (October 2006).

I. Kodeli and E. Sartori, “Input Descriptions for ANGELO2 Code,” NEA Data Bank Version 2.2 (December 2002).

**b. Other useful documentation**

*The following
reference describes the use of the library:*

G. Aliberti* et al.*, “Nuclear data sensitivity,
uncertainty and target accuracy assessment for future nuclear systems,” *Annals
of Nuclear Energy*, 33(8), 700--733 (May 2006).

*The
covariance matrices were taken from the following sources:*

R. E. MacFarlane, D. W. Muir, *The NJOY Nuclear Data Processing
System, Version 97, Manual*, LA-12740-M (1994).

I. Kodeli and E. Sartori, “Neutron Cross-section Covariance Data
in Multigroup Form and Procedure for Interpolation to Users' Group Structures for
Uncertainty Analysis Applications,” in *Proc. of PHYSOR'90, Int. Conf. on the
Physics of Reactors: Operation, Design and Computation, Marseille, PI-11 - PI-20,
23-27 April 1990*, Marseille; NEA computer package NEA-1264/03 - /05 (ZZ-VITAMIN-J/COVA:
Covariance Matrix Library based on JEF-1, ENDF/B-IV and -V data).

D. W. Muir, *The Evaluation and Application of Redundant Cross-Section
Covariances*, LA-UR-86-3786-Rev (Nov. 1986); NEA computer package DLC-0091 (ZZ-COVFILS:
30-Group Neutron Cross-Section Covariance Library from ENDF/B-V).

D.W. Muir, “COVFILS-2: Neutron Data and Covariances for Sensitivity
and Uncertainty Analysis,” *Fusion Techn*. 10 (3), part 2B, 1461 (Nov. 1986);
NEA computer package DLC-0137 (ZZ-COVFILS-2: 74-Group Covariance Data for Fusion
Reactors (ENDF/B-V)).

I. Kodeli, “VITAMIN-J/COVA/EFF-3 Cross-Section Covariance Matrix
Library and its Use to Analyse Benchmark Experiments in SINBAD Database,” *Fus.
Eng. Design *75-79 (2005) 1021-1025; NEA Package NEA-1264/05 (ZZ-VITA.-J/COVA/EFF3
Cross-section covariance data from EFF-3).

G. Chiba, ERRORJ- Covariance Processing Code System for JENDL, Ver. 2, JNC TN9520, 2003-008, Sept. 2003.

O. Bersillon *et al.* International Reactor Dosimetry File
2002 (IRDF-2002), 2006, IAEAgency, Vienna, Technical Reports Series No. 452, ISBN
92-0-105106-9, Dec. 2006, http://www-pub.iaea.org/MTCD/publications/PDF/TRS452_web.pdf.

P. Schillebeeckx and A. Trkov (Eds): Evaluated Nuclear Data For Th-U Fuel Cycle, Summary Report of the Third Research Coordination Meeting, IAEA, Headquarters, Vienna, Austria, 30 January to 2 February 2006, INDC(NDS)-0494, February 2006, http://www-nds.iaea.org/reports-new/indc-reports/indc-nds/indc-nds-0494.pdf.

Data available from: http://www-nds.iaea.org/Th-U/.

The package is transmitted on a CD disc which contains the reports listed in section 10.a, the installation and source files, data files, and test cases.

August 2012.

**KEYWORDS: **COVARIANCE MATRICES, CROSS SECTIONS