RSICC CODE PACKAGE CCC-765

1.         NAME AND TITLE

GANDR/SEMOVE:       Program for Calculating Derivatives of Processed Multigroup Nuclear Data by Discrete Differences.

The code is part of the GANDR system, see http://www-nds.iaea.org/gandr.  

2.         CONTRIBUTORS

OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

3.         CODING LANGUAGE AND COMPUTER

Fortran 77; Linux (C00765PCX8600).

4.         NATURE OF PROBLEM SOLVED

SEMOVE is a Fortran 77 computer program for computing the derivatives of processed multigroup nuclear data with respect to the individual parameters of the Global Assessment of Nuclear Data Requirements (GANDR) library. The basic premise is that a user has chosen a multigroup processing program such as NJOY and has developed a script that allows the calculation of all nuclear data of interest in his selected group structure and with his selected weight function. The file “njg” included in this distribution is an example of such a user-supplied script.

A distinctive feature of the GANDR project is that the fundamental data uncertainties are assumed to reside, not in the ENDF evaluations, but in the parameters of the GANDR library. To interface the GANDR library with normal sensitivity tools (such as SUSD3D), and thereby to permit the GANDR library to be improved by exploiting the information content of accurate integral data, we need to be able to calculate the changes in the multigroup cross sections that result from changes in the GANDR parameters.

5.         METHOD OF SOLUTION

The SEMOVE program assumes the existence of reference ENDF and PENDF files, such as are normally supplied to the GROUPR module for multigroup processing. The SEMOVE program performs a lengthy series of discrete alterations. In each alteration, one of the (up to 700) GANDR parameters for the material of interest is either increased or (in the case of odd-numbered Legendre coefficients) decreased by 1%. The GANDR parameters are defined such that perturbing one parameter leads to an altered cross section table (in a PENDF file) or an altered distribution (in an ENDF file), but not both. This might be called the “exclusive or” property of the parameters. To keep track of the numerous altered files, a specific data directory structure is employed.

The SEMOVE code can, with a single execution, populate the reserved data directories with the perturbed ENDF and PENDF files required to calculate all parameter derivatives for a selected nuclide. An illustration of how this works in practice is provided in the accompanying documentation.

6.         RESTRICTIONS OR LIMITATIONS

The SEMOVE program is currently restricted to cases where the final calculation is performed with the GROUPR module, with the results being written to a GROUPR format (GENDF) output file, as is the case with the script njg. There are no other restrictions placed on the type or complexity of the processed data. The NJOY99.259 code with updates given in files ‘upbro’ and ‘upgro' was used to run the sample case. If later versions of NJOY99 are used the compatibility of the provided inputs should be verified. Likewise, recent NJOY99 versions may include some of the above updates.

7.         TYPICAL RUNNING TIME

Hardware dependant; around 7 hours on a Dell Precision 530 workstation running Red Hat Linux 7.1.

8.         COMPUTER HARDWARE REQUIREMENTS

Linux environment.

9.         COMPUTER SOFTWARE REQUIREMENTS:

A Fortran 77 compiler is required running under a Linux OS or Windows/Cygwin environment. NJOY-99.259 is required to run the test cases.

10.        REFERENCES

D.W. Muir, “SEMOVE, A Computer Program for Calculating Derivatives of Processed Multigroup Nuclear Data by Discrete Differences.”

11.        CONTENTS OF CODE PACKAGE

The package is transmitted in a self-extracting executable which includes documentation, source files, C Shell scripts (CSH or TCSH) and sample problems.

12.        DATE OF ABSTRACT

June 2012.

KEYWORDS:       NUCLEAR DATA, SENSITIVITY ANALYSIS