1. NAME AND TITLE
ALPHN: Code System for Calculating (alpha,n) Neutron Production in Canisters of High-Level Waste.

Data Libraries
STPN6A.OU3: Stopping powers and yields.
CURIES.IN9: Alpha curies of each actinide.

2. CONTRIBUTOR
Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER
Fortran 77; IBM PC 486 compatible.

4. NATURE OF PROBLEM SOLVED
The ALPHN program calculates the (alpha,n) neutron production rate in a mixture of chemical species receiving alpha-particles from alpha-emitting actinides.

5. METHOD OF SOLUTION
The user specifies the mass fractions of the chemical species in the mixture and the curies of each actinide. Other basic data (stopping powers and thick-target yields) are supplied from the data libraries distributed with the program. The method of West is used to calculate the neutron yield for a single alpha-particle energy. The total neutron production rate per canister is the summation taken over all actinides i, and actinide i is assumed to emit a-particles with a single average initial energy.

6. RESTRICTIONS OR LIMITATIONS
The total mixture yield calculated is a source term and does not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously.

7. TYPICAL RUNNING TIME
Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 34 seconds on an IBM AT personal computer.

8. COMPUTER HARDWARE REQUIREMENTS
ALPHN was developed on IBM personal computers. The executable included in the package was created on an IBM PC 486 compatible with 640 kB memory and a math co-processor.

9. COMPUTER SOFTWARE REQUIREMENTS
The executable included in the package was created using the Ryan-McFarland Version 2.10 compiler under DOS Version 5.0.

10. REFERENCE
R. Salmon and O. W. Hermann, "ALPHN: A Computer Program for Calculating (alpha,n) Neutron Production in Canisters of High-Level Waste," ORNL/TM-12239 (October 1992).

11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one DS/HD diskette which includes the Fortran source, executable file, data libraries and sample case input and output.

12. DATE OF ABSTRACT
April 1993.

KEYWORDS: ISOTOPE INVENTORY; MICROCOMPUTER; NEUTRON; WASTE MANAGEMENT