1. NAME AND TITLE

BSPRP2: Code System to Process DORT Boundary-Flux Files.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77; IBM RS/6000 (P00372/IRISC/00).

4. NATURE OF PROBLEM SOLVED

BSPRP2 processes DORT BNDRYS-formatted boundary-flux files to prepare input boundary sources for other DORT calculations. DORT is not included in this package but is distributed within the CCC-650/DOORS code package. BSPRP2 handles both regular and variable-mesh geometries. Scale factors may be applied to normalize the source or to correct for streaming. [When correcting for streaming, the code assumes flat spatial distributions of the factors over two ranges and a cosine-power transition (varying by group) between the regions.] For the new DORT problem, the code will calculate a source for a different mesh and/or a different quadrature. Several options are available for converting the fluxes from one mesh/quadrature to another and for normalizing the output source to that for the portion of the input boundaries spanned by the output geometry. Direction-integrated group sources are printed after the mesh change and after the quadrature change if any. These should be the same values printed by DORT for a calculation using the new source. The user is referred to the document for hints on inputting i-sets for a change-of-mesh case.

5. METHOD OF SOLUTION

BSPRP2 calculates the new fluxes by either (1) mixing the old fluxes with coefficients determined by the fraction of the new interval or solid angle spanned by the old intervals or solid angles or (2) assuming linear variation of the fluxes in space and direction and interpolating to obtain the flux at the assumed centroid of the new interval and solid angle. Conversions are made on the basis of either flux or current, and results are converted to flux following the current conversion. Details of the scale factor application are found in the documentation for the code.

6. RESTRICTIONS OR LIMITATIONS

The flux conversions are performed using an assumed variation of the flux over space and direction. Other assumptions may yield different results. However, with reasonable quadratures, the converted fluxes have generally been reliable. Arrays are flexibly-dimensioned and memory is computed at run time. Hence, there should be no practical limitation on problem size. Fluxes are converted one energy group at a time, keeping storage requirements to a minimum. Additionally, the reuse of storage occupied by the input flux array allows the quadrature conversion to be performed without the need for an increase in memory allocation.

7. TYPICAL RUNNING TIME

The code runs in a very short time, on the order of seconds even for a production problem. For example, the sample problem converts a 61-group, 96-direction, 100-mesh-interval boundary flux to an 82-mesh-interval boundary flux (same quadrature) in 0.019 min. or about 1.1 s on an RISC 6000 model 340 workstation running under AIX 4.2.

8. COMPUTER HARDWARE REQUIREMENTS

The supplied program was adapted for the IBM RISC 6000 workstation. The code was previously run on the UNICOS Cray and required a few modifications to run on the IBM workstation (mainly time, date, and memory allocation functions).

9. COMPUTER SOFTWARE REQUIREMENTS

The system runs under AIX 4.2 using the XLF Fortran 77 compiler.

10. REFERENCE

C. O. Slater, "BSPRP2 - A Computer Program to Prepare Source Input from DOT-IV 'BNDRYS' -Formatted Multiple Boundary Source Data Sets," ORNL Intra-Laboratory Correspondence (September 22, 1980).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and a CD-ROM which includes the BSPREP2 source files and test case input and output written in a compressed Unix tar file.

12. DATE OF ABSTRACT

January 1999.

KEYWORDS: DATA PROCESSING, UTILITY; WORKSTATION