1. NAME AND TITLE

NITRAN: Neutron Transport Code System Based On Anisotropic Scattering

AUXILIARY ROUTINES

DDXS: Double differential cross section generation program.

NITRAN-1: One-dimensional transport code for spherical and slab geometries

NITRAN-2: Two-dimensional transport for slab (x-y) geometry

NITRAN-TD: One-dimensional transport code for spherical geometry for time dependent problems.

2. CONTRIBUTORS

Osaka University, Osaka, Japan.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77; FACOM M-380.

4. NATURE OF PROBLEM SOLVED

NITRAN is a neutron transport code system based on a rigorous treatment of anisotropic scattering. Double differential cross sections are used (see DLC-123/DDXLIB).

5. METHOD OF SOLUTION

NITRAN includes DDXS, a nuclear data processing code used to generate group constants of the double differential type. The input to DDXS can be ENDF/B-IV, ENDF/B-VI or JENDL-3 cross sections.

In the NITRAN calculation, angular dependent transfer cross sections (kernels) are used as scattering cross sections. They are obtained from integrating the product of the double differential neutron emission cross sections and the angular transfer probabilities. The transport codes are based on discrete ordinates. To solve the one-dimensional (slab and sphere) transport, NITRAN-1 is used. For two dimensions, NITRAN-2 is used. For time- dependent problems NITRAN-2D is included.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

None noted.

8. COMPUTER HARDWARE REQUIREMENTS

NITRAN will run on the FACOM M-380. With minor modifications, the codes can be modified to run on the IBM mainframes.

9. COMPUTER SOFTWARE REQUIREMENTS

NITRAN codes are written in FORTRAN 77.

10. REFERENCES

a. Included in the package:

Fujio Maekawa. NITRAN Manual. OKTAVIAN Report A-90-01, Osaka University, Osaka, Japan, March 1990.

A. Takahashi, D. Rusch. Fast Rigorous Numerical Method for the Solution of the Anisotropic Neutron Transport Problem and the NITRAN System for Fusion Neutronics Application, Part II, KfK 2832/II, KFK, Karlsruhe, October 1979.

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one 1600 or 6250 bpi tape, containing the FORTRAN 77 sources and sample problems; TOTAL RECORDS -- 283,846.

12. DATE OF ABSTRACT

February 1991.