NESC0702 COMPARE

1. NAME OR DESIGNATION OF PROGRAM:  COMPARE

3. DESCRIPTION OF PROBLEM OR FUNCTION

COMPARE  performs   transient
calculation of  the thermodynamic conditions in  volumes connected
by flowing junctions with provision  for mass and energy addition.
Volume  thermodynamics  and  junction flows  are  for  homogeneous
mixtures of:  steam, two-phase water,  any three perfect gases, or
combinations of  the above.   Critical vent flow  is based  on the
Moody equation.  Subcritical flow is based on compressible orifice
flow  of an  ideal gas-like  mixture  with inlet  and exit  losses
resulting  in a  polytropic flow  process.  Flow  with inertia  is
calculated   on  the   basis  of   an  incompressible   subelement
relationship.   The  program  was  written  to  perform  transient
subcompartment analysis of nuclear power plants.

4. METHOD OF SOLUTION

Volume thermodynamics and  junction flows are
determined independently in a  quasi-static explicit manner.  Mass
and energy  inflow or outflow accounting  for each volume  is done
first for each  time increment, assuming vent  flows are constant.
Thermodynamic equilibrium is assumed  and state points determined.
The resulting  thermodynamic conditions  are assumed  constant and
used to calculate the new vent  flows between volumes for the next
time interval.  Flow with inertia is  calculated on the basis of a
solution to the  momentum equation with constant  density and flow
area.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The        program
currently provides for maxima of:
   100 volumes
   200 junctions
     5 mass and energy addition tables (blowdown sets)
Water  temperature  is restricted  to  the  range 278-620 ? K
(40-656 deg. F).

6. TYPICAL RUNNING TIME

A two-volume, one-junction problem requires
0.002 second per time-step (CDC7600) or 0.012 second (IBM370/165).

7. UNUSUAL FEATURES OF THE PROGRAM

Ideal-like    gas     polytropic
equations are  used to calculate  orifice flow,  including losses.
Two-phase water with air flow  is calculated, and inertial effects
are included.

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES:

- R.G. Gido, R.G. Lawton, C.I. Grimes, and J.A. Kudrick:
  COMPARE - A Computer Program for the Transient Calculation of a
  System of Volumes Connected by Flowing Vents
  LA-NUREG-6488-MS (September 1976).
- R.G. Gido, R.G. Lawton, C.I. Grimes, and J.A. Kudrick:
  COMPARE - A Computer Program for the Transient Calculation of a
  System of Volumes Connected by Flowing Vents
  LA-NUREG-6488-MS (September 1976).

11. MACHINE REQUIREMENTS

35,000 (octal) words (CDC6600,7600) or 125K
bytes (IBM360,370)

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

    SCOPE    3.4
(CDC6600), SCOPE 2.1 (CDC7600), OS/360,370 (IBM360,370).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Numerical   output    may   show    system-dependent   variations,
particularly for  the small  values printed  for  the early  time-
steps.

15. NAME AND ESTABLISHMENT OF AUTHOR

   7600          R. G. Gido and R. G. Lawton
                 Los Alamos Scientific Laboratory
                 P. O. Box 1663
                 Los Alamos, New Mexico  87544
   370           C. I. Grimes and J. A. Kudrick
                 U. S. Nuclear Regulatory Commission
                 Washington, D. C.  20555

File name	File description	Records
NESC0702_01.001	SOURCE	1749
NESC0702_01.002	INPUT FOR S.P.	66
NESC0702_01.003	OUTPUT OF S.P.	2227
NESC0702_01.004	INFORMATION	4

File name	File description	Records
NESC0702_02.001	SOURCE PROGRAM (F4,EBCDIC)	1709
NESC0702_02.002	SAMPLE PROBLEM INPUT DATA	66
NESC0702_02.003	SAMPLE PROBLEM PRINTED OUTPUT	2208