NEA-0500: ALARM, Thermohydraulics of BWR with Jet Pumps During LOCA

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NEA-0500 ALARM. (Abstract last modified 24-MAY-1985)

ALARM, Thermohydraulics of BWR with Jet Pumps During LOCA

Abstract Table of Contents:

OPERATING SYSTEM

OTHER RESTRICTIONS

1. NAME OR DESIGNATION OF PROGRAM - ALARM-B2.

2. COMPUTER FOR WHICH PROGRAM IS DESIGNED AND OTHER MACHINE VERSION PACKAGES AVAILABLE -

To request or retrieve programs click on the one of the active versions below. A password and special authorization is required.

Explanation of the status codes.

Program-name Package-ID Status ALARM-B1 NEA-0500/01 Tested ALARM-B2 NEA-0500/02 Tested

Machines used: Package-ID Orig.Computer Test Computer NEA-0500/01 IBM 370 series IBM 370 series NEA-0500/02 FACOM M-380 IBM 3084Q

3. NATURE OF PHYSICAL PROBLEM SOLVED - ALARM-B2 which is an improved version of ABARM-B1 is a computer program to analyze thermo-hydraulic phenomena of BWR during a blowdown period under a large-break loss-of-coolant accident condition with special emphasis on the heat transfer phenomena in the core region.

4. METHOD OF SOLUTION - A so called volume-junction method is used to present fluid conservations. The primary system is divided into a number of special elements called "control-volumes". The system of partial differential equations describing fluid conservations for a stream-tube are integrated over a number of control volumes. The resulting set of simultaneous differential equations that is based on the assumptions of one-dimensional, homogeneous and thermal- equilibrium flow is linearized and solved 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-Nicholson implicit method. In order to simulate the blowdown heat transfer phenomena, the code has correlation packages for heat transfer coefficient and critical heat flux.
The heat generation in the core is given by a point reactor kinetics model with six groups of delayed neutrons and decay of eleven groups of fission products and actinides. The solution technique of the reactor kinetics is based on the Runge-Kutta method.
ALARM-B2 has the models to simulate various components incorporated in BWRs such as jet pumps, recirculation pumps, steam separators, valves, and so on. The discharge and injection systems are modeled by leak and fill systems, respectively.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - As this has been developed to simulate a blowdown thermo-hydraulic transient during a large break LOCA, users must pay attention when applying the code to any medium or small break LOCAs or to later phases of a large-break LOCA.

6. TYPICAL RUNNING TIME - The running time depends on the number of time steps and the complexity of the nodalization of the system to be analyzed. A rough estimate of CPU time requirement is about 2 ms/volume.step on FACOM M-380. As a BWR is usually modelled by 10 to 20 volumes with time step size of 0.1 to 1 milliseconds, the total CPU time for a transient of 50 seconds is 0.3 to 1 hours.

NEA-0500/02:

NEA-DB executed the test cases included in the package on IBM 3084Q. The following CPU times were found for the different steps:
         program                    seconds
         -------                    -------
         conversion program         0.68
         ALARM-B2: test case 1      4.3
                   test case 2      3.64
         MERGE                      0.49
         SPLPLOT-1                  0.71

7. UNUSUAL FEATURES OF THE PROGRAM -

8. RELATED AND AUXILIARY PROGRAMS - All input data are read in free format via a generalized subroutine REAG which converts BCD information to integer or floating numbers. The graphic information is edited by the SPLPACK-1 program which has been developed for plotting the time dependent thermo-hydraulic variables.

9. STATUS
NEA-0500/01: 01-NOV-1977 Tested at NEADB
NEA-0500/02: 24-MAY-1985 Tested at NEADB

10. REFERENCES  -
- K. Muramatsu et Al.
  User's Manual for SPLPACK-1: A Program Package for Plotting and
  Editing of Experimental and Analytical Data of Various Transient
  Systems,
  JAERI-M 83-166 (1983).
- T. Shimizu
  Verification of LOCA/ECCS Analysis Code ALARM-B2 and THYDE-B1 by
  Comparison with RELAP4/MOD6/U4/J3 (in Japanese),
  JAERI-M 82-094 (1982).
- K. Asai , K. Tsuchiashi
  A Subroutine Reading Data in Free Format (in Japanese),
  JAERI-M 4458 (1971).
NEA-0500/01:
- M. Akimoto
  "ALARM-B1, A Computer Program for Boiling Water Reactor Blowdown
  Analysis"
  JAERI-M 6968, March 1977.
NEA-0500/02:
- Fumimasa Araya:
  ALARM-B2: A Computer Program for Analysis of Large Break Loca
  of BWR.  JAERI-M 9655  (Sept.1981; Rev. Sept.1984)

11. MACHINE REQUIREMENTS - The required storage is about 1600K bytes.

NEA-0500/02:

Main storage requirements on IBM 3084Q are as follows: Conversion program: 128K bytes
             ALARM-B2:             1096K bytes
             MERGE:                 328K bytes
             SPLPLOT-1:             644K bytes

12. PROGRAMMING LANGUAGE(S) USED -
NEA-0500/01: FORTRAN-IV
NEA-0500/02: FORTRAN-77

13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED - The program can be executed without specification of optimization using the FORTRAN-77 compiler of the FACOM M-380 standard operating system.

NEA-0500/02:

MVS-SP (IBM 3084Q).

14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS -

15. NAME AND ESTABLISHMENT OF AUTHOR -
   F. Araya and M. Akimoto
   Department of Nuclear Safety Evaluation
   Japan Atomic Energy Research Institute
   Tokai-mura, Naka-gun, Ibaraki-ken, Japan

16. MATERIAL AVAILABLE -
NEA-0500/01:
NEA0500_01.001    LIBRARY DATA ( STEAM TABLE IN BCD FORM )         2620 records
NEA0500_01.002    LIBRARY CONVERSION PROG. BCD TO BINARY (F4)        10 records
NEA0500_01.003    JCL OF  CONVERSION PROGRAM                          5 records
NEA0500_01.004    SOURCE PROGRAM - F4 - EBCDIC                     8499 records
NEA0500_01.005    JCL                                                 6 records
NEA0500_01.006    SAMPLE PROBLEM INPUT DATA                         172 records
NEA0500_01.007    SAMPLE PROBLEM PRINTED OUTPUT                    2032 records
NEA-0500/02:
NEA0500_02.001    INFORMATION FILE                                  224 records
NEA0500_02.002    ALARM-B2 SOURCE PROGRAM (CARD IMAGES)           21717 records
NEA0500_02.003    SPLPACK SOURCE PROGRAM (CARD IMAGES)             5779 records
NEA0500_02.004    SPLPLOT-1 SOURCE PROGRAM (CARD IMAGES)           5674 records
NEA0500_02.005    SPLUCL2 SOURCE PROGRAM (CARD IMAGES)             3968 records
NEA0500_02.006    CONVERSION PROGRAM FOR STEAM TABLES                38 records
NEA0500_02.007    MERGE    SOURCE PROGRAM (CARD IMAGES)             713 records
NEA0500_02.008    SPLSUBR  SOURCE PROGRAM (CARD IMAGES)             252 records
NEA0500_02.009    LOCF SOURCE (ASSEMBLER)                             7 records
NEA0500_02.010    SETB99 ASSEMBLER ROUTINE                           80 records
NEA0500_02.011    ADDITIONAL SUBROUTINES SOURCE                      30 records
NEA0500_02.012    JCL                                               323 records
NEA0500_02.013    ALARM-B2 TEST CASE 1 INPUT DATA                   253 records
NEA0500_02.014    ALARM-B2 TEST CASE 2 INPUT DATA                    34 records
NEA0500_02.015    MERGE TEST CASE INPUT DATA                          2 records
NEA0500_02.016    SPLPLOT-1 TEST CASE INPUT DATA                     26 records
NEA0500_02.017    ALARM-B2 TEST CASE 1 PRINTED OUTPUT              3078 records
NEA0500_02.018    ALARM-B2 TEST CASE 2 PRINTED OUTPUT              2396 records
NEA0500_02.019    MERGE TEST CASE PRINTED OUTPUT                    111 records
NEA0500_02.020    STEAM TABLE DATA LIBRARY (FORMATTED)             3867 records
NEA0500_02.021    SPLPLOT LABELING DATA                             272 records

17. CATEGORIES -

- G. Radiological Safety, Hazard and Accident Analysis

Keywords: BWR REACTORS, ENTHALPY, FLUID FLOW, HEAT TRANSFER, HYDRAULICS, LOCA, PRESSURE, PUMPS, REACTOR SAFETY, THERMODYNAMICS

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