NESC0512 THETA1B

1. NAME OR DESIGNATION OF PROGRAM:  THETA1B

3. DESCRIPTION OF PROBLEM OR FUNCTION

THETA1B computes  the thermal
response  characteristics of  a nuclear  fuel rod  subjected to  a
loss-of-coolant accident environment.

4. METHOD OF SOLUTION

THETA1B solves the  two-dimensional diffusion
equation  for   a  single   fuel  rod   and  the   one-dimensional
conservation of energy equation for  the associated fluid channel.
The two  solutions are linked at  the fuel rod-fluid  interface by
the boundary conditions of surface temperature and heat flux.  The
energy equations in  the fuel rod and fluid channel  are solved by
several numerical differencing techniques.   Normally the fuel rod
equation is solved explicitly and the  fluid equation is solved by
the method of characteristics.  The  heat transfer model considers
forced  convection  in  subcooled liquid  and  superheated  vapor,
nucleate  boiling,  forced   convection  vaporization,  transition
boiling, and stable film boiling.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Small   time-steps
are used, resulting in long running times.

6. TYPICAL RUNNING TIME

Approximately 30 minutes are required for a
30-second transient.

7. UNUSUAL FEATURES OF THE PROGRAM

Various  options  are  available
for  heat transfer  correlations in  the  different heat  transfer
regions.  The code  may also be used  to model electrically-heated
test elements used in out-of-pile decompression experiments.

8. RELATED AND AUXILIARY PROGRAMS

CINDA3G (reference 2)  is used to
solve the conduction equation.

10. REFERENCES

C.  J.  Hocevar  and  T.  W.  Wineinger,  THETA1B,  A
Computer Code for Nuclear Reactor  Core Thermal Analysis, IN-1445,
February 1971.
             J. D. Gaski, Chrysler Improved Numerical Differencing
Analyzer  for  Third Generation  Computers,  Chrysler  Corporation
Technical Note TN-AP-67-287, October 1967.
             ACC Programming Note 72-23, THETA1B Transmittal Tape,
April 1972.

11. MACHINE REQUIREMENTS:  400K bytes of core memory are required.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:   OS/360.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

                 C. J. Hocevar and  T. W. Wineinger
                 EG&G Idaho, Inc.
                 P. O. Box 1625
                 Idaho Falls, Idaho  83401

File name	File description	Records
NESC0512_01.001	SOURCE PROGRAMME PART-1 (THETA -FILE)	3327
NESC0512_01.002	SOURCE PROGRAMME PART-2 (CINDA1-FILE)	9743
NESC0512_01.003	SOURCE PROGRAMME PART-3 (CINDA2-FILE)	7328
NESC0512_01.004	CARDS FOR LINK.EDITOR TO BE USED IN THE PREP	225
NESC0512_01.005	JCL+INPUT(NETWORK AND GENERAL DATA) TO RUN T	683
NESC0512_01.006	PRINTED OUTPUT OF THE EXEC. OF THETA-FILE	528
NESC0512_01.007	FORTRAN SOURCE GENERATED BY THE EXEC. OF THE	441
NESC0512_01.008	OUTPUT OF THE EXEC. OF THE FINALY LINKED MOD	1584