1. NAME AND TITLE

ACFA: A Versatile Activation Code for Coolant and Structural Materials.

AUXILIARY ROUTINES

REDUCE: Generates reduced decay data library.

DATA LIBRARIES

DECAY

PHOTON YIELD

UKCTR IIIA

NEUTRON FLUX

2. CONTRIBUTOR

Kernforschungsanlage Jülich GmbH, Federal Republic of Germany.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 3033.

4. NATURE OF PROBLEM SOLVED

ACFA calculates the neutron-induced activation, afterheat, biological hazard potential, transmutation and gamma-ray spectra in a nuclear system. The quantities of interest may be calculated by interval and/or by zone of the system considered. To calculate the transmutation coefficients for the neutron-induced reactions the code uses multigroup activation cross sections and space-dependent multigroup neutron fluxes in one- or two-dimensional geometry.

5. METHOD OF SOLUTION

ACFA uses the matrix exponential method and the Bateman solution to solve a large system of coupled linear first-order ordinary differential equations with constant coefficients. The numerical methods for solving the equations are taken from ORIGEN.

6. RESTRICTIONS OR LIMITATIONS

ACFA is flexibly dimensioned; the storage requirements are determined for the particular problem at execution time. The length of the decay chains constructed by the code only depends upon the decay and cross section data given on the nuclear data libraries.

7. TYPICAL RUNNING TIME

The sample problem ran in 1.25 cpu min.

8. COMPUTER HARDWARE REQUIREMENTS

ACFA runs on the IBM 3033 computer. From four to eight direct access devices are required depending upon the problem. Standard input-output units are used; it requires < 4000 I/O.

9. COMPUTER SOFTWARE REQUIREMENTS

ACFA is operable on the IBM OS 360 with Fortran H Extended Enhanced Compiler. Standard software may be used. It uses 744 K in the GO step.

10. REFERENCE

H. Brockmann and U. Ohlig, "ACFA - A Versatile Activation Code for Coolant and Structural Materials," ISSN 0366-0885 (September 1983).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and 1 DS/HD (1.2 MB) diskette which contains the source code and sample problem input, and output from the sample problem.

12. DATE OF ABSTRACT

January 1986.

KEYWORDS: ACTIVATION; GAMMA-RAY