1. NAME AND TITLE

EPRI-CINDER: General Point-Depletion and Fission Product Code System and Four-Group Fission Product Neutron Absorption Chain Data Library Generated from ENDF/B-IV for Thermal Reactors.

EPRI-CINDER is an updated version of CINDER.

2. CONTRIBUTORS

Electric Power Research Institute, Palo Alto, California.

Los Alamos National Laboratory, Los Alamos, New Mexico.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6600.

4. NATURE OF PROBLEM SOLVED

EPRI-CINDER calculates, for any specified initial fuel (actinide) description and flux or power history, the fuel and fission-product nuclide concentrations and associated properties. Other nuclide chains can also be computed with user-supplied libraries. The EPRI-CINDER Data Library (incorporating ENDF/B-IV fission-product processed 4-group cross sections, decay constants, absorption and decay branching fractions, and effective fission yields) is used in each constant-flux time step calculation and in time step summaries of nuclide decay rates and macroscopic absorption and barns-per-fission (b/f) absorption cross sections (by neutron group). User-supplied nuclide decay energy and multigroup-spectra data libraries may be attached to permit decay heating and decay-spectra calculations.

An additional 12-chain library, explicitly including 27 major fission-product neutron absorbers and 4 fictitious nuclides, may be used to accurately calculate the aggregate macroscopic absorption buildup in fission products.

5. METHOD OF SOLUTION

The EPRI-CINDER version of the code retains the input library format of the original widely-used CINDER code yet offers some new options and greatly improved numerical roundoff control and a fission product library suitable for light water reactors.

The temporal concentrations of fission-product nuclei produced in a nuclear reactor are described by a large set of coupled differential equations, each nuclide concentration being determined by a history of gains from direct fission yield, transmutation, and radioactive decay from parent nuclei, and losses from its own decay and particle absorption. All versions of CINDER employ a linearized Markovian chain representation of these coupled nuclides, each chain representing a unique path from nuclide to nuclide. There is no numerical integration.

6. RESTRICTIONS OR LIMITATIONS

Arbitrary chains, nuclide data, and irradiation histories can be specified by the user. The supplied library of fission product cross sections is for use in typical light water reactors using cross sections in one to four arbitrary energy groups, as noted below. Other spectra and group structures are available using the code and multigroup data in EPRI NP-356 Part 1.

The EPRI-CINDER fission-product data libraries include 4-group radiative capture cross sections in the energy structure below.

GROUP ENERGY BOUND (eV)

1 1.0 x 107

2 8.2085 x 105

3 5.5308 x 103

4 6.2506 x 10-1

1.0 x 10-5

7. TYPICAL RUNNING TIME

Fission-product absorption calculations performed on a CDC-6600 with the 84-chain library generally require approximately 30 seconds to compile the code and to input and store all data. Each time step at power requires approximately 2 seconds and each shutdown time step requires approximately 1 second.

8. COMPUTER HARDWARE REQUIREMENTS

EPRI-CINDER was designed to run on the CDC-6600.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCES

T. R. England, W. B. Wilson, and M. G. Stamatelatos, Fission Product Data for Thermal Reactors. Part 2: Users Manual for EPRI-CINDER Code and Data, EPRI NP-356 Part 2 (LA-6746-MS) (December 1976).

T. R. England, W. B. Wilson, and M. G. Stamatelatos, Fission Product Data for Thermal Reactors. Part 1: A Data Set for EPRI-CINDER Using ENDF/B-IV, EPRI NP-356 Part 1 (LA-6745-MS) (December 1976).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

December 1981.

KEYWORDS: FISSION PRODUCTS; ENDF/B FORMAT; FISSION PRODUCT INVENTORY; POINT DEPLETION