last modified: 09-MAY-1989 | catalog | categories | new | search |

NEA-0646 DASQHE.

DASQHE, Dancoff Correlation for Infinite Circular Rod Assembly in Square or Hexagonal Lattice

top ]
1. NAME OR DESIGNATION OF PROGRAM:  DASQHE.
top ]
2. COMPUTERS
To submit a request, click below on the link of the version you wish to order. Only liaison officers are authorised to submit online requests. Rules for requesters are available here.
Program name Package id Status Status date
DASQHE NEA-0646/01 Tested 09-MAY-1989

Machines used:

Package ID Orig. computer Test computer
NEA-0646/01 DEC VAX 8810
top ]
3. DESCRIPTION OF PROBLEM OR FUNCTION

DASQHE produces Dancoff corrections for an infinite array of circular rods placed in a square or hexagonal lattice in a moderator. (The Dancoff correction  is the relative reduction in the in-current of resonance neutrons into the fuel in a closely packed lattice compared to the in-current into a single fuel rod in an infinite moderator, due to the shadow-  ing effect of adjacent rods.) The calculation may be done for a series of moderator cross sections if desired.
top ]
4. METHOD OF SOLUTION

A collision probability method is used.
The trapezoidal rule is used for the integration of the Dancoff correction double integral, the linear and angular variables being discretized. Instead of considering a series of pairs of rods, a straightforward "chopper" method is utilised that disregards rods after a certain distance. (For principles of the solution method see references 2 and 3.) The effects of the fuel can (and gas coolant channel) is approximated by the homogenization of a gap surrounding each rod.
top ]
5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The neutron path is followed through 100 rows of rods if no intersection is found, that is the Dancoff correction is calculated for the central rod that is, the Dancoff correction is calculated for the central rod in an array of 201 x 201 rods. Even for the smallest moderator cross section used in the calculations, the distance to the nearest  disregarded rod is 10 mean free paths.
top ]
6. TYPICAL RUNNING TIME

48 Dancoff corrections for various moderator  cross sections in both square and hexagonal lattices took 2.4 minutes on the IBM 7044 using DASQHE together with a simple main routine.
NEA-0646/01
About 2 seconds per Dancoff factor are required on a VAX 8810 computer. NEA-DB ran the test case included in this package in about 40 minutes of CPU time.
top ]
7. UNUSUAL FEATURES OF THE PROGRAM:
top ]
8. RELATED AND AUXILIARY PROGRAMS

DASQHE is a Fortran IV development  of the code DANCOFF-5 which was written in Autocode for the Ferranti Mercury computer of AB Atomenergi. Previous Mercury Autocode programs were DANCOFF-2 and DANCOFF-4.

DANCOFF-3 is a Fortran program that calculates Dancoff corrections for fuel element rods near water gaps and for fuel rod clusters.
top ]
9. STATUS
Package ID Status date Status
NEA-0646/01 09-MAY-1989 Tested at NEADB
top ]
10. REFERENCES

- I. Carlvik:
  "A Method for Calculating Collision Probabilities in General
   Cylindrical Geometry and Applications to Flux Distributions and
   Dancoff Factors"
  U.N. Int. Conf. on the Peaceful Uses of Atomic Energy, Geneva, 3,
  1964, Vol. 2, Geneva 1965, p. 225.
- I. Carlvik:
  1964, AB Atomenergi, Sweden (Internal Report RFR-282).
NEA-0646/01, included references:
- I. Carlvik:
  Dancoff Correction in Square and Hexagonal Lattices
  AE-257 (November 1966)
top ]
11. MACHINE REQUIREMENTS

NEA 0646/01: 405K bytes of VAX 8810 main storage are required, including Bickley functions, sample main program, and system routines.
top ]
12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
NEA-0646/01 FORTRAN-IV
top ]
13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

DASQHE needs to be called from another program, or run with a simple user-written main routine.
NEA-0646/01
VMS V5.0-1 (VAX 8810).
top ]
14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:
top ]
15. NAME AND ESTABLISHMENT OF AUTHOR

          I. Carlvik
          Aktiebolaget Atomenergi
          Stockholm, Sweden.
top ]
16. MATERIAL AVAILABLE
NEA-0646/01
File name File description Records
NEA0646_01.001 Information File 75
NEA0646_01.002 DASQHE Source + Sample MAIN + Bickley Rout. 331
NEA0646_01.003 DASQHE Sample Problem Printed Output 1406
top ]
17. CATEGORIES
  • B. Spectrum Calculations, Generation of Group Constants and Cell Problems

Keywords: Dancoff correction, collisions, control elements, fuel rods, moderators, probability, reactor lattices, resonance.