NESC9978 COBRA-3C/RERTR.

1. NAME OR DESIGNATION OF PROGRAM:  COBRA-3C/RERTR.

3. DESCRIPTION OF PROGRAM OR FUNCTION

COBRA-3C/RERTR is a modification of the COBRA-3C/MIT, thermal-hydraulic nuclear reactor subchannel analysis program for research and test reactors (RERTRs), which are operated at low pressure and low temperatures and may use  plate-type fuel elements and heavy water as coolant. COBRA-3C/RERTR  incorporates critical heat flux correlations suitable for low-pressure systems, flow instability correlations, two-phase heat  transfer coefficients suitable for research and test reactors, thermodynamic properties of heavy water, the capability of calculating the thickness of oxide film on an aluminum fuel plate, and the void fraction model based on the Bowring bubble detachment criterion. A plotting capability is included to display transient results.
The program calculates the steady-state power margins for reactors using either rod- or plate-type fuel elements. For the rod-type fuel the power margin is limited by surface clad temperature based on subcooled nucleate boiling heat transfer. For the plate-type fuel the power margin is limited by the flow instability rate (FIR), which is defined as the ratio of the reactor power at which the flow instability will occur to the operating power. The program is also capable of calculating the limiting thermal-hydraulic parameters in a RERTR for both loss-of-flow and power-ramp transients. COBRA-3C/RERTR uses the proprietary ISSCO DISSPLA graphics software which is not included.

4. METHOD OF SOLUTION:

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME:

NEA-DB ran the test cases included in this package on an IBM 3090 computer. The following execution times were required (in CPU seconds): case 1: 0.25; case 2: 0.25; case 3: 0.30; case 4:  1.27; case 5: 5.42; case 6: 9.47.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES:

- Jason Chao:
  COBRA-3C/RERTR - A Thermal-Hydraulic Subchannel Code with Low
  Pressure Capabilities
  Science Applications, Inc. (December 25, 1980).
- W.L. Woodruff:
  Supplemental Information for COBRA-3C/RERTR
  ANL Applied Physics Division Memorandum (February 1983).

11. MACHINE REQUIREMENTS:

The test cases executed on IBM 3090 in 320 Kbytes of main storage .

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

MVS/DFP with compiler VS FORTRAN LEVEL 2.5.0 (IBM 3090)

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

          J. Chao and J. Matos
          Argonne National Laboratory

File name	File description	Records
NESC9978_01.001	Information file	113
NESC9978_01.002	JCL examples to compile, link, execute	147
NESC9978_01.003	COBRA-3C/RERTR FORTRAN source	7930
NESC9978_01.004	COBRA-3C/RERTR ASSEMBLER source	246
NESC9978_01.006	JCL examples for COBRAPLT	27
NESC9978_01.007	COBRAPLT FORTRAN source	752
NESC9978_01.008	COBRA-3C/RERTR sample problem 1 input data	33
NESC9978_01.009	COBRA-3C/RERTR sample problem 2 input data	33
NESC9978_01.010	COBRA-3C/RERTR sample problem 3 input data	33
NESC9978_01.011	COBRA-3C/RERTR sample problem 4 input data	45
NESC9978_01.012	COBRA-3C/RERTR sample problem 5 input data	62
NESC9978_01.013	COBRA-3C/RERTR sample problem 6 input data	79
NESC9978_01.014	Sample problem 1 printed output	951
NESC9978_01.015	Sample problem 2 printed output	952
NESC9978_01.016	Sample problem 3 printed output	952
NESC9978_01.017	Sample problem 4 printed output	1250
NESC9978_01.018	Sample problem 5 printed output	3250
NESC9978_01.019	Sample problem 6 printed output	4526