1. NAME AND TITLE

 MONK 6.3: A General Purpose Monte Carlo Neutronics Code System.

AUXILIARY ROUTINES

 SCAN 6.3: Geometry checking package for MONK 6.3.

CARD2BIN: Converts card image library to binary.

BIN2CARD: Converts binary library to card image.

DATA LIBRARY

 MONKLIB: Point energy library based on UK Nuclear Data Library.

2. CONTRIBUTORS

 United Kingdom Atomic Energy Authority, Chemical Plants, Laboratories and Criticality Group, Safety and Reliability Directorate, Warrington, England; the Reactor Physics Division, Winfrith, Dorchester, England; and the OECD NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

 Fortran H Extended and Assembler language; IBM 3090. (C00393I303300)

4. NATURE OF PROBLEM SOLVED

 A more current version of MONK is available commercially.  MONK 6.3 is a Monte Carlo neutronics program which calculates the reactivity of an assembly of materials whose geometry can be described to almost any degree of complexity. It can calculate collision rates, keff, and flux distribution in the steady state or with a given source. Its parameters can be described as follows:

(a) Geometry: three-dimensional systems with high complexity.

 (b) Sources: a variety of point, line, surface or volume sources, specified in energy and direction, may be used.

 (c) Scoring: by collisions, boundary crossings, or track length.

 (d) Data: based on a close representation of UKNDL.

(e) Cycle: tracks fission to fission or boundary to boundary.

 A wide variety of sources can be used, for the first stage only, for every stage, or for each occasion when the system becomes extinct. The use of very finely tabulated point energy data in MONK 6.3 provides a model of the nuclear interactions which is capable of dealing with resonance shielding, resonance overlap, thermalization, fast fission thresholds and all such matters which involve the fine details of cross section shapes.

5. METHOD OF SOLUTION

 MONK 6.3 employs the Monte Carlo technique using direct simulation. The geometry package allows the combination of simple shapes into complex systems.

6. RESTRICTIONS OR LIMITATIONS

 The size of the problem is limited only by the available storage.

7. TYPICAL RUNNING TIME

 The time required to run the program is dependent upon the user's problem. The series of sample problems require 5 to 105 s on the IBM 3090.

8. COMPUTER HARDWARE REQUIREMENTS

 The code is operable on the IBM 3090 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

 The system was tested using Fortran-H Extended (IEFAA8) Level 2.3.0 (June 1978) with MVS operating system.

10. REFERENCES

 Comments on the MONK 6.3 Document, Informal Notes (March 1987).

 MONK 6.3 Export Tapes, Informal Notes.

 V. S. W. Sherriffs, "MONK A General Purpose Monte Carlo Neutronics Program," SRD-R-86 (January 1978).

K. C. Rushton, "The Monte Carlo Code MONK A Guide to Its Use for Criticality Calculations," SRD-R-88 (August 1978).

N. R. Smith, "A Guide to the New Features Contained in MONK 6.2," MMC/P56 Amendment 2.

 R. J. Brissenden and N. R. Smith, "Instructions for Commissioning MONK 6.1", MMC/P51.

 Running Instructions for MONK 6, Informal Notes, MMC/P41.

R. Wakeford and N. R. Smith, "Initial Results from the Preliminary Testing of Group-MONK 6," MMC/P58 (December 1982).

 R. Wakeford and N. R. Smith, "Further Results form the Preliminary Testing of Group-MONK 6," MMC/P64 (February 1983).

 Informal Notes:

 The Risley Free Form Input Routines.

MONK: Colour Graphics.

 Colour Scan on the ICL 2982 Using a Sigma Terminal.

 Functional Specification of Auxiliary Routines.

Subroutines with a Variable Number of Arguments.

N. Smith, "PREMONK - The MONK6 Preprocessing Program."

 R. J. Brissenden, "MONK6 Documentation (MONK Code Users Manual)," (March 1985).

11. CONTENTS OF CODE PACKAGE

 Included are the referenced documents and either one DC6150 tape cartridge in TAR format or 7 DS/HD 3.5-in. (1.44 MB) diskettes in self-extracting compressed DOS files which contain the source codes and sample problem input and output.

12. DATE OF ABSTRACT

 February 1982; January 1986; March 1987.