NEA-0453 DEPCO-MULTI.

DEPCO-MULTI, Subcooled Decompression in PWR Primary System LOCA

NAME OR DESIGNATION OF PROGRAM, COMPUTER, NATURE OF PHYSICAL PROBLEM SOLVED, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, REQUIREMENTS, LANGUAGE, OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED, ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: DEPCO-MULTI.

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Only liaison officers are authorised to submit online requests. Rules for requesters are available here.

Program name	Package id	Status	Status date
DEPCO-MULTI	NEA-0453/01	Tested	01-NOV-1977

Machines used:

Package ID	Orig. computer	Test computer
NEA-0453/01	IBM 370 series	IBM 370 series

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3. NATURE OF PHYSICAL PROBLEM SOLVED

DEPCO-MULTI is used to analyze the subcooled decompression in a multiple pipe netork such as a PWR primary coolant system after an instantaneous pipe break.

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4. METHOD OF SOLUTION

The unsteady one dimensional mass, momentum and energy conservation laws are converted to a set of compatibility conditions and characteristic directions equivalent to them. After the simplification of the compatibility conditions, they are numerically integrated by the explicit formula.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

(1) Maximum number of different thermodynamic initial conditions - 5 (2) Maximum output points of - pressure history - 5
pressure difference history - 3
flow velocity history - 1
(3) The assumptions of thermal equilibrium, no buoyancy effect, no heat transfer and one-dimensional analysis are used.

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6. TYPICAL RUNNING TIME

About 823 seconds of CPU time are required for the typical case which has 661 mesh points and 35 msec time interval. The total time step number is 916.

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7. UNUSUAL FEATURES OF THE PROGRAM

(1) The running time is short because of the simplification of the isentropic processes.
(2) The method of characteristics has the advantage of being closely related to the pressure wave transport phenomena.
(3) The heat transfer coefficients which are important in the core heat transfer analysis during LOCA could be calculated locally because the velocity distribution in the core can be obtained.

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8. RELATED AND AUXILIARY PROGRAMS

The program GPLOT1 is used to plot the result calculated by DEPCO-MULTI. The program steam is suited to calculate the steam tables based on JSME steam tables.

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9. STATUS

Package ID	Status date	Status
NEA-0453/01	01-NOV-1977	Tested at NEADB

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10. REFERENCES

NEA-0453/01, included references:

- K. Namatame and K. Kobayashi:
  Digital Computer Code DEPCO-MULTI for Calculating the Subcooled
  Decompression in PWR LOCA
  JAERI-M 5623 (February 1974).
- K. Namatame and K. Kobayashi:
  Subcooled Decompression Analysis of The Rosa and The Loft
  Semiscale Blowdown Test Data by the Digital Computer Code
  DEPCO-MULTI
  JAERI-M 6340 (December 1975).

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11. HARDWARE REQUIREMENTS

MACHINE REQUIREMENTS. About 120k words main storage, 11 data files, plotter.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NEA-0453/01	FORTRAN-IV

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13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED: Monitor V of FACOM 230/60.

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14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

All subroutines which are not included refer to GSSL (Genken subroutine library) and should be included in other systems.

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15. NAME AND ESTABLISHMENT OF AUTHOR

    K. Namatame and K. Kobayashi
    Japan Atomic energy Research Institute
    Tokai-Mura, Naka-Gun, Ibaraki-Ken
    Japan.

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16. MATERIAL AVAILABLE

NEA-0453/01

File name	File description	Records
NEA0453_01.001	INFORMATION	4
NEA0453_01.002	LIBRARY DATA IN BCD FORM ( SATZ)	1448
NEA0453_01.003	LIBRARY DATA IN BCD FORM ( WATF)	24980
NEA0453_01.004	LIBRARY DATA IN BCD FORM ( WATG)	11070
NEA0453_01.005	LIBRARY CONV. PROG. (BCD TO BINARY - SATZ)	12
NEA0453_01.006	LIBRARY CONV. PROG. (BCD TO BINARY - WATF&G)	23
NEA0453_01.007	JCL OF THE CONVERSION PROGRAMS	6
NEA0453_01.008	SOURCE PROGRAM - F4 - EBCDIC	3800
NEA0453_01.009	PLOTTING ROUTINES - F4 - EBCDIC	415
NEA0453_01.010	JCL	30
NEA0453_01.011	SAMPLE PROBLEM INPUT DATA	59
NEA0453_01.012	SAMPLE PROBLEM PRINTED OUTPUT	1338

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17. CATEGORIES

G. Radiological Safety, Hazard and Accident Analysis

Keywords: coolant loops, loss-of-coolant accident, pipes, pwr reactors, thermodynamics.