NEA-1187 BOREAS.

1. NAME OR DESIGNATION OF PROGRAM:  BOREAS.

3. DESCRIPTION OF PROGRAM OR FUNCTION

BOREAS is a three-dimensional reactor core simulator based upon a nodal model. It is designed for  realistic nuclear and thermal-hydraulic simulation of the burnup cycle  of a light  water reactor  with a square  fuel lattice. A
separate auxiliary code REFUEL performs reloading operations.

4. METHOD OF SOLUTION

One- and one-half-group nodal model for the reactor core. Simultaneous neutronic and thermal-hydraulic iterations using Jacobi, Gauss-Seidel or SOR methods. The Levy and Zuber-Findlay or Premoli-Francisco-Prina correlations are used for the void fraction calculation.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Maximum core dimen-  sions 250x25 = 6250 nodes and 13x26x25 (IxJxK). 5 bundle types, 9
fuel types, 5 channel types. May easily be extended if sufficient memory available.

6. TYPICAL RUNNING TIME

About 10 CP seconds on the CDC CYBER 180 computer for test problem with 121x10 nodes.

BOREAS ran at NEA-DB on a CDC CYBER 830 in 35.5 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

The program package includes the auxiliary code REFUEL for reloading operations.

10. REFERENCES:

- R. Hoeglund:
  A Nodal Method of Calculating Power Distributions for LWR-Type
  Reactors with Square Fuel Lattices.
  VTT NEL Report 51  (June 1980)
- R. Hoeglund:
  Nea Data Bank Version of BOREAS.
  RFD-04/1988  (March 14, 1988)
- R. Hoeglund:
  BOREAS - A Reactor Core Simulation Code for Burnup Cycle Studies
  on Light Water Reactors with a Square Fuel Lattice:
  Report 1 - Methods of Solution (The Neutronic Model)
  REP-5/80  (April 23, 1980)
  Report 2 - Methods of Solution (The Thermohydraulic Model)
  REP-10/80 (August 5, 1980)
  Report 3 - Input Description
  REP-3/81  (April 27, 1981)
  Report 4 - Refuelling Code
  REP-7/81  (September 3, 1981)
  Report 5 - Supplementary Input Description
  REP-2/83  (January 17, 1983)

11. MACHINE REQUIREMENTS:  About 260 000 octal words.

To run the test case of BOREAS inclded in this package  on a CDC CYBER 830, 270,0200 (octal) words of main storage are required.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  CDC CYBER 180-840 NOS 2.

NOS 2.5.1 (CDC CYBER 830).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

     Randolph Hoeglund
     Technical Research Centre of Finland
     Nuclear Engineering Laboratory
     P.O.B. 169
     SF-OO181 HELSINKI
     FINLAND

File name	File description	Records
NEA1187_03.001	Information file	75
NEA1187_03.002	JCL and control information	22
NEA1187_03.003	CORDISP FORTRAN source	57
NEA1187_03.004	KTABLEP FORTRAN source	57
NEA1187_03.005	REFUEL FORTRAN source	830
NEA1187_03.006	REFUEL input data	28
NEA1187_03.007	BOREAS FORTRAN source	3710
NEA1187_03.008	BOREAS input data	94
NEA1187_03.009	KTABLEP printed output	102
NEA1187_03.010	REFUEL printed output	138
NEA1187_03.011	BOREAS printed output	1339