1. NAME AND TITLE
ALARM-B2: A Computer Code System for Analysis of a Large Break LOCA of a BWR.
Japan Atomic Energy Research Institute (JAERI), Tokyo, Japan, through the OECD Nuclear
Energy Data Bank, Gif-sur-Yvette, France.
3. CODING LANGUAGE AND COMPUTER
Fortran IV and Assembler; IBM 360/370, 3084.
4. NATURE OF PROBLEM SOLVED
ALARM-B2 is a modified version of ALARM-B1 and is a tool to analyze thermo-hydraulic
phenomena of a BWR during a postulated large break LOCA.
5. METHOD OF SOLUTION
ALARM-B1 does not calculate the heat transfer to the coolant during the transient but specifies it by input data. ALARM-B2 provides a one-dimensional heat conduction equation, a heat transfer correlation package, and a point reactor kinetics equation to analyze the heat transfer phenomenon in the core region during a LOCA. It also calculates thermal hydraulics in the pressure vessel and the primary coolant loop during the transient of a large break of the recirculation line.
The system of partial differential equations describing fluid conservation for stream-tube are
integrated over a number of control volumes. The resulting set of simultaneous equations that is based
on the assumptions of one-dimensional, homogeneous, thermal-equilibrium flow is linearized and
advanced for a small time increment by a simple explicit numerical technique. The one-dimensional
heat conduction equations describing temperature profiles within solid material are written in finite
difference forms which are linearized and solved by the Crank-Nicolson implicit method.
6. RESTRICTIONS OR LIMITATIONS
7. TYPICAL RUNNING TIME
No study has been made by RSIC of typical running times for ALARM-B2.
8. COMPUTER HARDWARE REQUIREMENTS
ALARM-B2 is operable on the IBM 360/370 and the IBM 3084 computers.
9. COMPUTER SOFTWARE REQUIREMENTS
Fortran IV and Assembler compilers are required.
F. Araya, "ALARM-B2: A Computer Program for Analysis of Large Break LOCA of BWR,"
JAERI-M 9665 (Revised September 1984).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and two (1.2MB) DOS diskettes which contain the source
code and sample problem input.
12. DATE OF ABSTRACT
KEYWORDS: NUCLEAR SAFETY