1. NAME AND TITLE

ATTOW-K: Multigroup Two-Dimensional Removal-Diffusion (Spinney Method) Shielding Code System.

AUXILIARY ROUTINE

ATTOWLIB: Cross Section Handling Code and Library.

AUXILIARY DATA

ATTOWLIB Data Library.

ATTOW (IBM 7090) was originally placed in RSIC via the OECD NEA Data Bank, Gif-sur-Yvette, France. This version was updated and converted to IBM 360 by Karlsruhe Nuclear Research Center.

2. CONTRIBUTOR

Karlsruhe Nuclear Research Center, Federal Republic of Germany and The Reactor Group, HQ, UKAEA, Risley, Warrington, England.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/65/75/91 and IBM 370/165.

4. NATURE OF PROBLEM SOLVED

ATTOW-K is designed to solve the multigroup diffusion equations, reinforced where necessary by removal theory, for non-multiplying media in two dimensions of either cylindrical or rectangular coordinates. It is used for calculating neutron flux distributions, activations of reactor materials and of test samples, generation of heat in the shields, neutron currents and other quantities.

ATTOW-K was thus designed specifically as a two-dimensional shielding program with special facilities for source problems. The one-dimensional problem may be solved by CCC-72/COMPRASH.

5. METHOD OF SOLUTION

The Spinney removal-diffusion method of calculating neutron transport is described in the abstract of CCC-72/COMPRASH.

In ATTOW-K, the finite difference expression is solved by iteration using accelerated successive line over-relaxation. The removal source expression is handled by Gaussian integration using a stored table of zeros and weights.

ATTOW-K uses Karlsruhe multigroup constant sets and the CCC-121/SABINE removal cross sections, included in the package.

6. RESTRICTIONS AND LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been done by RSIC of typical running times.

8. COMPUTER HARDWARE REQUIREMENTS

The original code system was designed for the IBM 7090 and was converted to run on the IBM 360/370 series.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV G or H compiler and an OS 370-360 Operating System are required.

10. REFERENCES

G. Bonisch and H. W. Wiese, "ATTOW-K, The Karlsruhe IBM 360/65 Version of the 2-D Removal Diffusion Shielding Code," KFK 1869 (EURFNR-1138) (October 1973).

W. D. Collier and G. C. Curtis, "ATTOW, A Two-Dimensional Shielding Program," TRG Report 1466 (R) (1967).

A. Daneri and G. Toselli, "TranslationLetter to Garcia De Viedma," CNEN, Bologna.

A. Daneri, L. Martelli, and G. Toselli, "ATTOW-BA New Version of Removal and Diffusion Shielding Code ATTOW," CNEN, Bologna.

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

April 1974; revised July 1982 and March 1990.