1. NAME AND TITLE

CHAINS-PC: Code System to Compute Atom Density of Members of a Single Decay Chain.

2. CONTRIBUTORS

General Electric Corp., Cincinnati, Ohio and the National Energy Software Center, Argonne, Illinois through the DOE Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

DOS 3.1; FORTRAN 77. (C00604/IBMPC/00)

4. NATURE OF PROBLEM SOLVED

CHAINS computes the atom density of members of a single radioactive decay chain. The liinearity of the Bateman equations allows tracing of interconnecting chains by manually accumulating results from separate calculations of single chains. Re-entrant loops can be treated as extensins of a single chain. Looses froem the chain are also tallied.

5. METHOD OF SOLUTION

The Bateman equations are solved analytically using double-precision arithmetic. Poles are avoided by small alterations of the loss terms. Multigroup fluxes, cross sections, and self-shielding factors entered as input are used to compute the effective specific reaction rates. The atom densities are computed at any specified times.

6. RESTRICTIONS OR LIMITATIONS

Maxima of 100 energy groups, 100 time values, 50 members in a chain.

7. TYPICAL RUNNING TIME

RSIC executed the sample problem in 2 seconds on a PC 486, running 33 megahertz.

8. COMPUTER HARDWARE REQUIREMENTS

The IBM PC version requires 76 Kbytes of memory and an 80x87 math coprocessor. RSIC executed the sample problem in 2 seconds on an PC 486, running 33 megahertz.

9. COMPUTER SOFTWARE REQUIREMENTS

The IBM PC version requires the Lahey F77L or a suitable alternative compiler capable of accepting NAMELIST input.

10. REFERENCE

W. B. Henderson, "Program CHAINS," (NMP-856) (March 27, 1967).

11. CONTENTS OF CODE PACKAGE

One DS/HD (1.44MB) diskette including the Fortran source, executable, and sample case input and output.

12. DATE OF ABSTRACT

July 1992.