NEA-0624 JOSHUA.

1. NAME OR DESIGNATION OF PROGRAM:  JOSHUA.

3. DESCRIPTION OF PROBLEM OR FUNCTION

JOSHUA simulates the neutronics, hydraulics, burnup and refuelling of water-cooled reactors in two or three dimensions. It is a whole-reactor code which uses cell-averaged data calculated in a lattice cell calculation such as used by WIMS. JOSHUA evaluates the overall power distribution through the reactor, and integral properties such as reactivity.

4. METHOD OF SOLUTION

The neutronics calculation, based on the program BASHAN, uses diffusion theory with an in-channel mesh point  respresentation in Cartesian x-y-z geometry. The hydraulics calculation for void feedback is general enough to deal with pressure tube and pressure vessel reactors. An iterative procedure between the flux solution and the hydraulics calculation ensures consistency between the rating and density distributions. Optional features include soluble poison and the reactivity feedback effects  of xenon poisoning and fuel temperature as well as control rod or interlattice tube representation.

The approach followed in modelling the burnup process is to integrate the equations describing isotopic change within the framework of the lattice cell calculation.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:  JOSHUA is limited to two energy groups.

6. TYPICAL RUNNING TIME:

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

WIMS supplies the data such as the  macroscopic cross sections. The FACADE system may be used to transfer data from WIMS to JOSHUA. The flux solution is based on that used in the code BASHAN.

10. REFERENCES

- D.F. Pearce:
  JOSHUA III - A Three-Dimensional Diffusion Code with Thermal
  Hydraulic Feedback for Fuel Management Studies in Water Cooled
  Reactors
  AEEW-R788 (1973).

- M. J. Roth:
  A Review of the Equations Solved by the Computer Program JOSHUA
  AEEW-R 1165 (April 1978)
- M. J. Roth, Mrs. M. A. Thompson:
  The FACADE Version of JOSHUA
  AEEW-R 1186 (July 1978)

11. MACHINE REQUIREMENTS:

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

          D. F. Pearce
          AEE Winfrith
          Dorchester, Dorset
          United Kingdom.

File name	File description	Records
NEA0624_01.001	INFORMATION	14
NEA0624_01.002	ASSEMBLER SOURCE	1568
NEA0624_01.003	FORTRAN SOURCE	10924
NEA0624_01.004	OVERLAY CARDS	22
NEA0624_01.005	JCL	92
NEA0624_01.006	INPUT FILE FOR TEST CASE	17
NEA0624_01.007	INPUT CARDS FOR TEST CASE	47
NEA0624_01.008	OUTPUT OF TEST CASE	1815
NEA0624_01.009	DATA LIBRARY (BINARY)	45