NESC0694 FRAPCON2 & V1M4

1. NAME OR DESIGNATION OF PROGRAM:  FRAPCON2 and FRAPCON2/V1M4

3. DESCRIPTION OF PROBLEM OR FUNCTION

FRAPCON2/V1M4 is the most recent in the FRAPCON series of fuel rod response modeling programs. FRAPCON series, like the earlier FRAP-S and GAPCON-THERMAL codes, is designed to predict the steady-state long-term burnup response of oxide fuel in light water reactors (LWRs). In addition, these codes  generate the initial conditions for transient fuel rod analysis by the FRAP-T or RELAP programs. FRAPCON2 calculates the temperature, pressure, deformation, and failure histories of a fuel rod as functions of time-dependent fuel rod power and coolant boundary conditions. The phenomena modeled by the code include heat conduction through the fuel and cladding, cladding elastic and plastic deformation, fuel-cladding mechanical interaction, fission gas release, fuel rod internal gas pressure, heat transfer between fuel and cladding, cladding oxidation, and heat transfer from cladding to coolant. Material properties, water properties, and heat transfer correlation data are included.

4. METHOD OF SOLUTION

FRAPCON2/V1M4 iteratively calculates the interrelated effects of fuel and cladding temperature, rod internal  gas pressure, fuel and cladding deformation, release of fission product gases, fuel swelling and densification, cladding thermal expansion and irradiation-induced growth, cladding corrosion, and crud deposition as functions of time and fuel rod specific power. The calculation begins with processing of input data. Next, the initial fuel rod state is determined through a self-initialization calculation. Time is advanced according to the input-specified time- step size, a steady state solution is determined, and the new fuel rod state obtained. The new fuel rod state provides the initial state conditions for the next time step and these calculations are cycled in this manner for the user-specified number of time steps.
The solution for each time step consists of a calculation of the temperature of the fuel and cladding, a calculation of fuel and cladding deformation, and a calculation of the fission product generation, void volume, and fuel rod internal gas pressure. When the FRACAS-I mechanics model is selected, the fuel rod failure probability is calculated also. Each of the calculation is performed in a separate subcode.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

FRAPCON2/V1M4 is limited to single-rod analysis with 11 radial nodes. FRAPCON2/V1M4 allows a maximum of 18 axial nodes and a maximum of 200 power time steps.
The thermal models of the code are based on steady-state data and equations, therefore, calculated temperatures will become progressively inaccurate as input power histories result in power ramp rates greater than 0.02 percent per second. Similary, the gas release models are based on steady-state data and do not reflect release rates for rapid power changes. All of the thermal and machanics modeling options assume an axisymmetric fuel rod. Large deformations with greater than 5 percent strain will not be traced well. If the PELET option is selected, power step changes greater that 1.0 KW/ft per time step should not be used.

6. TYPICAL RUNNING TIME

The running time varies with the number of time steps and the number of axial nodes specified. NESC executed the FRAPCON2/V1M4 sample problem in 195 CP seconds on a CDC CYBER170/875.

NEA-DB executed the test case on CYBER 174 in 277 CP seconds.

The test case included in this package ran at NEA-DB on a VAX 8810 computer in 77.7 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

The FRAPCON series replaced the FRAP-S1, FRAP-S2, and FRAP-S3 series of programs. The fuel temperature computation used in the FRAPCON series was taken from the GAPCON-THERMAL2 code (NESC 618). FRAPCON2/V1M4 generates the initial conditions for transient fuel rod analysis used either by FRAP-T6 (NESC 658) or RELAP4/MOD7 (NESC 369).

MATPRO              Material Properties Package

10. REFERENCES

- Donald L. Hagrman and Gregory A. Reymann,
  Ed.,Matpro-Version 11 A Handbook of Materials Properties for Use
  in the Analysis of Light Water Reactors fuel Rod Behavior,
  NUREG/CR-0497 (TREE-1280) Rev. 1, February 1980.
- M.P. Bohn,
  FRACAS--A Subcode for the Analysis of Fuel Pellet-Cladding
  Mechanical Interaction,
  TREE-NUREG-1029, April 1977.
- FRAPCON2/V1M4, NESC No. 694.C176, FRAPCON2/V1M4 Tape Description
  and Implementation Information,
  National Energy Software Center Note 88-28, December 21, 1987.

- G.A. Berna and al.:
  FRAPCON-2: A Computer Code for the Calculation of Steady State
  Thermal-Mechanical Behavior of Oxide Fuel Rods.
  NUREG/CR-1845 R3  (January 1981).
- G.A. Berna, D.D. Lanning and W.N. Rausch:
  FRAPCON-2 Developmental Assessment. NUREG/CR-1949 (July 1981).
- D.L. Hagrman, G.A. Reymann and R.E. Mason:
  MATPRO - Version 11(Rev. 1): A Handbook of Materials Properties
  for Use in the Analysis of Light Water Reactor Fuel Rod Behavior.
  NUREG/CR-0497 (Feb. 1980).
- G.A. Berna et al.:
  FRAPCON-2 "A Computer Code for the Calculation of Steady State
  Thermal-Mechanical Behavior of Oxide Fuel Rods"
  NUREG/CR-1845 (January 1981).
- Donald L. Hagrman et Al.:
  MATPRO-Version 11 (Revision 1) - A Handbook of Materials
  Properties for use in the Analysis of Light Water Reactor Fuel Rod
  Behavior
  NUREG/CR-0497 TREE-1280 (Rev. 1) , (February 1980).
- G.A. Berna et al.:
  FRAPCON-2 - Developmental Assement
  NUREG/CR-1949 (July 1981).
- P. Johnson:
  FRAPCON2/V1M4 Tape Description and Implementation Information
  NESC Note 88-28 (December 31, 1987).
- W.N. Rausch and D.D. Lanning:
  FRAPCON-2 Changes in Order to Create FRAPCON-2/V1M4
  Battelle Memorandum  (February 7, 1983).
- G.A. Berna and al.:
  FRAPCON-2: A Computer Code for the Calculation of Steady State
  Thermal-Mechanical Behavior of Oxide Fuel Rods.
  NUREG/CR-1845 R3  (January 1981).
- G.A. Berna, D.D. Lanning and W.N. Rausch:
  FRAPCON-2 Developmental Assessment. NUREG/CR-1949 (July 1981).
- D.L. Hagrman, G.A. Reymann and R.E. Mason:
  MATPRO - Version 11(Rev. 1): A Handbook of Materials Properties
  for Use in the Analysis of Light Water Reactor Fuel Rod Behavior.
  NUREG/CR-0497 (Feb. 1980).

11. MACHINE REQUIREMENTS

307,700 (octal) words of storage are required for FRAPCON2/V1M4 (CDC CYBER170).
FRAPCON2 (NESC0694/05): 247,000 octal words on CDC CYBER 174.
FRAP-S3 (NESC0694/06): 141,700 octal words of SCM and 206,000 octal  words of LCM on CDC 7600.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  NOS 2.2 (CDC CYBER170,875), NOS/BE (CDC CYBER176).

Test case execution under NOS 1.4-531.

VMS V5.0-1 (VAX 8810).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The FRAPCON2 plot option requires graphics routines not supplied with the package. The INEL library and IGS graphics system routines EXITG, GRIDG, LABELG, LEGNDG, LINESG, MODESG, NUMBRG, OBJCTG, PAGEG, RSETMG, SETSMG, SETUPG, SUBJEG, and TITLEG will have to be replaced  with locally-equivalent routines. The plot information is stored on  logical unit TAPE17 by FRAPCON2 and processed by the plotting routines which generate TAPE10 as plot output. TAPE10 is used at INEL to generate plots on the Information International Incorporated FR80 microfilm recorder or Calcomp plotting equipment.
   To run FRAPCON2/V1M4 memory must be preset to negative infinity.
In different computing environment the SEGLOAD directives can be modified to optimize execution time.

15. NAME AND ESTABLISHMENT OF AUTHOR

               W.N. Rausch, R.E. Williford, and
               D.D. Lanning
               Pacific Northwest Laboratory
               P.O. Box 999
               Richland, Washington 99352

               G.A. Berna and M.P. Bohn
               EG&G Idaho, Inc.
               P.O. Box 1625
               Idaho Falls, Idaho 83415

File name	File description	Records
NESC0694_05.003	FRAPCON2 INFORMATION FILE	54
NESC0694_05.004	FRAPCON2 MAIN SECTION SOURCE (FORTRAN-4)	15548
NESC0694_05.005	FRACAS-II SUBROUTINES (FORTRAN-4)	2191
NESC0694_05.006	PELET/RADIAL SUBROUTINES (FORTRAN-4)	3814
NESC0694_05.007	AXISYM SUBROUTINES (FORTRAN-4)	2553
NESC0694_05.008	MATPRO MATERIAL PROPERTIES PACKAGE	5018
NESC0694_05.009	GRASS SUBROUTINES (FORTRAN-4)	1700
NESC0694_05.010	FAST GRASS SUBROUTINES (FORTRAN-4)	1278
NESC0694_05.011	PLOTSR SUBROUTINES (FORTRAN-4)	230
NESC0694_05.012	FRAPCON2 INPUT FOR TEST CASE 1	30
NESC0694_05.013	FRAPCON2 OVERLAY DIRECTIVES	14
NESC0694_05.014	FRAPCON2 JCL FOR TEST CASE	47
NESC0694_05.015	FRAPCON2 OUTPUT OF TEST CASE 1	1943

File name	File description	Records
NESC0694_08.001	Information file	55
NESC0694_08.002	FRAPCON2/VIM4 main section UPDATE form	14375
NESC0694_08.003	FRACAS2 deformable pellet mechanics subr.	2200
NESC0694_08.004	PELET/RADIAL mechanics model sburoutines	3635
NESC0694_08.005	AXISYM FEM model subroutines	2591
NESC0694_08.006	MATRPO material properties package	5108
NESC0694_08.007	GRASF fission gas release subroutines	1353
NESC0694_08.008	FRPLT Plotting subroutines	233
NESC0694_08.009	Test case 1 input data	22
NESC0694_08.010	Test case 2 input data	23
NESC0694_08.011	Segment load directives	14
NESC0694_08.012	FRAPCON2/V1M4 UPDATEd file	15654
NESC0694_08.013	FRACAS2 UPDATEd file	2195
NESC0694_08.014	PELET UPDATEd file	3812
NESC0694_08.015	AXISYM UPDATEd file	2553
NESC0694_08.016	MATPRO UPDATEd file	5046
NESC0694_08.017	GRASF UPDATEd file	1347
NESC0694_08.018	FRPLT UPDATEd file	230
NESC0694_08.019	Test case 1 printed output	3623
NESC0694_08.020	Test case 2 printed output	5046

File name	File description	Records
NESC0694_09.001	Information file	57
NESC0694_09.002	FORTRAN source	32570
NESC0694_09.003	Input data	29
NESC0694_09.004	Output list	3545
NESC0694_09.005	Command procedure used for testing	8
NESC0694_09.006	Command procedure supplied by the author	30