RSIC CODE PACKAGE CCC-217



1. NAME AND TITLE

ORIGEN: Isotope Generation and Depletion Code SystemMatrix Exponential Method. 

CCC-702/ORIGEN-ARP is recommended for new ORIGEN users.


A Library of data, "DLC-38/ORYX-E, ORIGEN Yields and Cross SectionsNuclear
Transmutation and Decay Data from ENDF/ B-IV," is available from RSIC for use
with ORIGEN.



2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.



3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.



4. NATURE OF PROBLEM SOLVED

ORIGEN solves the equations of radioactive growth and decay allowing continuous
first order chemical processing and a neutron flux described by a three-region
spectrum. Complex decay and transmutation schemes can be treated. An example of
a problem which can be solved by ORIGEN is calculating decay heat in discharge
fuel sub-assemblies as a function of time from discharge. Note that this package
has not been updated in many years; and all new ORIGEN users are advised to request
the CCC-702/ORIGEN-ARP package, which is a PC application for Windows 95/NT or later.



5. METHOD OF SOLUTION

ORIGEN uses a matrix exponential method to solve a large system of coupled, linear,
first-order ordinary

differential equations with constant coefficients.

ORIGEN subroutines may be used by other calling programs to do isotope generation
and depletion calculations. 

Since alpha emission alone is of importance in some applications, the package includes
a supplementary actinide library in which total Q-values have been replaced by the
Q-values for alpha emission.



6. RESTRICTIONS OR LIMITATIONS

ORIGEN will handle 950 nuclides of which no more than 120 are actinides and their
decay daughters. Fission products are produced by fission rates of five different
actinides. In addition, there may be no more than 6000 non-zero elements in the
nuclear transmutation matrix. Numerical inaccuracies due to such things as too
coarse a time spacing are indicated by a warning message. Conversion difficulties,
except for those involving core usage, e.g., use of half words, have been eliminated.



7. TYPICAL RUNNING TIME

A problem with 40 time steps with 800 nuclides takes approximately 40 seconds on
the IBM 360/91 computer.



8. COMPUTER HARDWARE REQUIREMENTS

ORIGEN is operable on the IBM 360/370 computers. It requires approximately 265 K
using OVERLAY.



9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.



10. REFERENCES

Input/Output Notes.

Notes to Non-IBM Users.

Program Logic Diagram for the Blending Option.

C. R. Weisbin, Informal Notes: ORIGEN Sample Problem Using Fission Product File
Derived from ENDF/B-IV Fission Product Decay Data (May 1976).

ORIGEN Feedback from User (November 1975).

M. J. Bell, "ORIGENThe ORNL Isotope Generation and Depletion Code," ORNL-4628
(May 1973).



11. CONTENTS OF CODE PACKAGE

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



12. DATE OF ABSTRACT

August 1973; updated August 1975, 1981.



KEYWORDS: ISOTOPE INVENTORY; FISSION PRODUCT INVENTORY; MULTIGROUP; NEUTRON;
GAMMA-RAY SOURCE