RSICC CODE PACKAGE PSR-473

1. NAME AND TITLE

MARCH 2 Version.152: Code System to Model LWR Meltdown Accident Response.

2. CONTRIBUTORS

Battelle Memorial Institute, Columbus, Ohio through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; CDC CYBER and IBM 4331 (P00473CDCMF00).

4. NATURE OF PROBLEM SOLVED

MARCH2 describes the response of water cooled reactors to severe accidents, including consideration of the primary coolant system as well as the containment.

5. METHOD OF SOLUTION

Models are included to perform calculations from the start of an accident through the stages of blowdown, boiloff, core heat up, core meltdown, pressure vessel bottom head melting and failure, debris-water interaction in the reactor cavity, and the interaction of the molten debris with the concrete containment base pad. The mass and energy additions into the containment building during this accident scenario are continuously evaluated, and the pressure-temperature response of the containment is calculated either with or without the engineered safety features. The analysis accounts for metal-water reactions, combustion of hydrogen, and heat losses to structures in the containment. For a BWR the drywell and the wetwell are modeled as separate compartments, each having its own sump. For a PWR the containment usually has only one sump; and water from all compartments normally drains into that sump.

6. RESTRICTIONS OR LIMITATIONS

Application is limited to typical LWR systems. The containment can be divided into up to 8 interconnected compartment volumes.

7. TYPICAL RUNNING TIME

NESC executed the longest running sample problem in approximately 460 CP seconds on a CDC CYBER170/875.

8. COMPUTER HARDWARE REQUIREMENTS

MARCH2 ran on a CDC CYBER and IBM 4331 mainframe computers. The CDC version was designated Edition B and was submitted to NESC in June 1985. The sample problems were executed by NESC in June 1985 on a CDC CYBER170/875. The IBM version was submitted to NESC in June 1985 and tested in August 1985 on an IBM4331. The codes were not tested when they were transferred to RSICC and released in April 2001. No changes were made to the package by RSICC.

9. COMPUTER SOFTWARE REQUIREMENTS

The CDC FTN 5.1+587 compiler was used to run the code under NOS/BE 1.5-577 and NOS 2.2-605/587 (CDC CYBER180) and NOS 2.2-596/587 (CDC CYBER170/875). The VS Fortran compiler was used to run on the IBM 4331 under VM/CMS.

10. REFERENCE

R. O. Wooton, P. Cybulskis, and S. F. Quayle, "MARCH 2 (Meltdown Accident Response CHaracteristics) Code Description and User's Manual," NUREG/CR-3988, BMI-2115 (September 1984).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced document and 2 DS/HD diskettes which contain the CDC and IBM source files, control statements and test cases in self-extracting, compressed DOS files.

12. DATE OF ABSTRACT

April 2001.

KEYWORDS: CONTAINMENT; HEAT TRANSFER; LOCA; PWR; REACTOR ACCIDENT; REACTOR SAFETY; THERMAL HYDRAULICS