**1. NAME AND TITLE**

TPTRIA: A Computer Program for the Reactivity and Kinetic Parameters for Two-Dimensional Triangular Geometry by Transport Perturbation Theory

**AUXILIARY ROUTINES**

DIAMANT2 A discrete ordinates code to calculate direct and adjoint angular flux.

**2. CONTRIBUTOR**

Kernforschungszentrum Karlsruhe GmbH, Karlsruhe, Germany

**3. CODING LANGUAGE AND COMPUTER**

Fortran 77, ASSEMBLER; IBM 3083.

**4. NATURE OF PROBLEM SOLVED**

TPTRIA calculates reactivity, effective delayed neutron fractions and mean generation time for two-dimensional triangular geometry on the basis of neutron transport perturbation theory.

DIAMANT2 (also designated as CCC-414), is a multigroup two-dimensional discrete ordinates
transport code system for triangular and hexagonal geometry which calculates direct and adjoint
angular fluxes.

**5. METHOD OF SOLUTION**

DIAMANT2 is run to produce group cross sections, microscopic data of delayed neutron fractions
and spectra, isotope dependent prompt neutron fission spectrum, and direct and adjoint angular fluxes.
These are then the input to TPTRIA which computes reactivity by perturbation theory. TPTRIA has
two main options: exact perturbation calculation of reactivity, where the direct and adjoint angular
fluxes are used for unperturbed and perturbed systems, respectively; the other option is first order
perturbation calculations of probe reactivity where unperturbed angular fluxes are used.

**6. RESTRICTIONS OR LIMITATIONS**

Only two-dimensional regular triangular geometry is considered. There is no restriction on the
number of energy groups. At present only down scatter and an Sn approximation up to n=8 are
allowed.

**7. TYPICAL RUNNING TIME**

First order perturbation with S2, 4 energy groups, 3 probe samples for a mesh grid of 30x15 triangles took .11 second on a SIEMENS 7890 computer.

Exact perturbation calculation with S2, 4 energy groups for a mesh grid consisting of 30x15 triangles took .5 second on the SIEMENS 7890.

On an IBM 3083, using the sample case in the package, DIAMANT2 took about 9.48 seconds;
TPTRIA took 2.18 seconds.

**8. COMPUTER HARDWARE REQUIREMENTS**

IBM 3083, SIEMENS 7890.

1516 kb of main storage for DIAMANT2.

576 kb of main storage for TPTRIA.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran 77 compiler is required under the MVS operating system.

**10. REFERENCE**

K. Kobayashi, G. Buckel, K. Kufner, "TPTRIA, A Computer Program For the Reactivity and
Kinetic Parameters For Two-dimensional Triangular Geometry by Transport Perturbation Theory,"
KfK 4116 (October 1986).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one (1.2MB) DOS diskette.

**12. DATE OF ABSTRACT**

October 1990.

**KEYWORDS:** DISCRETE ORDINATES; MULTIGROUP; NEUTRON;
PERTURBATION THEORY; TRIANGULAR MESH; TWO-DIMENSIONS