RSICC CODE PACKAGE PSR-385

1. NAME AND TITLE

MOXY/MOD032: BWR Core Heat Transfer Code System.

2. CONTRIBUTORS

Idaho National Engineering Laboratory, Idaho Falls, Idaho through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV and Assembly language; IBM360; (P00385I036000).

4. NATURE OF PROBLEM SOLVED

MOXY is used for the thermal analysis of a planar section of a boiling water reactor (BWR) fuel element during a loss-of-coolant accident (LOCA). The code emplyoys models that describe heat transfer by conduction, convection, and thermal radiation, and heat generation by metal-water reaction and fission product decay. Models are included for considering fuel-rod swelling and rupture, energy transport across the fuel-to-cladding gap, and the thermal response of the canister. MOXY requires that time-dependent data during the blowdown process for the power normalized to the steady-state power, for the heat-transfer coefficient, and for the fluid temperature be provided as input. Internal models provide these parameters during the heatup and emergency cooling phases.

5. METHOD OF SOLUTION

An implicit numerical solution of the one-dimensional Fourier heat-conduction equation is used to compute heat conduction in fuel rods, solid inactive rods, and hollow inactive rods. Interchange of thermal radiation among surfaces is calculated using the network method described by Sparrow and Cess (See reference 5).

6. RESTRICTIONS OR LIMITATIONS

Maxima of 10 time-step sets, 10 print-interval sets, 50 normalized power-time pairs in considering time-dependent heat source, 50 convection heat transfer coefficient-time pairs in considering time-dependent convection, and 50 fluid temperatures.

7. TYPICAL RUNNING TIME

Approximately 3 minutes of CPU time are required to execute the sample problems on an IBM370/195. Approximately 2 minutes of CPU time are required to execute sample problems on a IBM 360.

8. COMPUTER HARDWARE REQUIREMENTS

300K bytes of storage (IBM360), standard input/output units, and 5 other units are required.

9. COMPUTER SOFTWARE REQUIREMENTS

OS/360, a Fortran IV compiler and assembler are required.

10. REFERENCES

a) Included in document:

D. R. Evans, "The MOXY Core Heat Transfer Code: Model Description and User's Guide," PG-R-76-003 (December 1976) with Revision 1 (February 14, 1977).

D. R. Evans, "The MOXY Core Heat Transfer Program: View Factor Model Improvements," RE-E-77-114 (February 8, 1977).

b) Background information:

WREM: Water Reactor Evaluation Model, Revision 1, NUREG-75/056 (May 1975).

E. M. Sparrow and R. D. Cess, "Radiation Heat Transfer" (1966).

"NRTS Environmental Subroutine Manual, ANC Document: (December 1972).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one diskette which includes source code and test case input and output. Also included is the NESC tape description list.

12. DATE OF ABSTRACT

April 1999.

KEYWORDS: HEAT TRANSFER; LOCA