CCC-0276 DOT-3.5.

1. NAME OR DESIGNATION OF PROGRAM:  DOT-3.5.

3. DESCRIPTION OF PROGRAM OR FUNCTION

DOT solves the Boltzmann transport equation in two-dimensional geometries. Principal applications are to neutron and/or photon transport, although the code can be applied to transport problems for any particles not subject to external force fields. Both homogeneous andexternal-source problems can be solved. Searches on multiplication factor, time absorption, nuclide  concentration, and zone thickness are available for reactor problems. Numerous edits and output data sets for subsequent use are available.

     DOT-3.5 improves the space-scaling algorithm.

     DOT-3.5/CAB contains group by group UPSCATTER scaling method.

DUCT calculates perturbations to the scalar flux caused by the presence of ducts filled with coolant.

VIP is a program for cross section sensitivity analysis using two- dimensional discrete ordinates transport calculations.

DGRAD calculates the directional flux gradients from DOT-3 diffusion theory flux tapes. In conjunction with VIP and TPERT, it allows the  use of diffusion theory fluxes to obtain exact and first-order perturbation reactivity changes. In order to calculate the reactivity associated with changes in reactor compositions using diffusion theory, it is necessary to fold not only the scalar fluxes with the appropriate cross sections, but also the average flux gradients with the diffusion coefficients. Since DOT diffusion theory does not directly calculate these gradients, it was necessary to calculate the needed quantities external to the DOT code.

TPERT is a perturbation code to obtain exact and first-order reactivity changes. TPERT is coupled to VIP which generates adjoint  forward fux tables using DOT-3 scalar flux tape information.

GRTUNCL calculates an analytical first-collision source for subsequent use in DOT.

4. METHOD OF SOLUTION

The method of discrete ordinates is used.
Balance equations are solved for the density of particles moving along discrete directions in each cell of a two-dimensional spatial  mesh. Anisotropic scattering is treated using a Legendre expansion of arbitrary order. Convergence can be accelerated by several optional schemes, including a pointwise rescaling technique.

DOT-3.5/E: Differs from DOT-3.5 in that exponential supplementary equations, as well as the usual diamond and weighted schemes, may be used to find the mesh-centre flux from the fluxes at the faces of the mesh.
The model:
1. always gives positive solutions and does not require any fixup techniques provided that the source is non-negative;
2. improves convergence rate in most neutron deep-penetration problems and, for any practical spatial discretization, always requires CPU times not only smaller than those required by DOT-3 mixed (linear + step fixup) model, but also shorter (generally 10-20%) than the times required by DOT-3.5 weighted difference model;
3. increasing spatial mesh size supplies solutions which are always  reasonable overestimates of the exact solution and its numerical behaviour is more stable and coherent than the mixed mode.
Experience up to now from several deep penetration problems in (r,z) and (x,y) geometry shows that, while for neutrons the exponential model almost always works very well, for gamma rays its behaviour may be critical and in some cases there is lack of convergence.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The total storage requirement is determined by a formula given in the input description. No other restrictions to problem size are applicable.

6. TYPICAL RUNNING TIME

Problems of practical value may range from 0.05 minutes to many hours in running time. A formula given in the input description allows estimation of central processor time for a  particular problem.
DOT-3.5/E: In the most deep penetration problems, DOT-3.5/E with exponential model is about 10 to 20 % faster than DOT-3.5 with weighted difference model.

7. UNUSUAL FEATURES OF THE PROGRAM

Flexible dimensioning is used throughout so that only the total storage requirement for a given problem is of concern. The program has two levels of external storage utilization in order to adapt to various problem requirements efficiently. Cross sections can be input on cards, from an ANISN-type nuclide-organized data set, or from a special group-organized data set which is valuable for very large cross section sets. A free-field data input format facilitates problem preparation. Special features which make DOT-3 well adapted to shielding problems include albedo boundary conditions, the capability to output fluxes at exterior or interior boundaries for use in 'bootstrap' problems, and an analytic first-collision source  calculation that mitigates ray-streaming effects in certain problems. Upscattering is allowed, and special routines are able to  synthesize two-dimensional flux guesses from one-dimensional data produced by the ANISN code. Diffusion theory is also available. The  convergence test can be restricted to specified zones.

DOT-3.5/E: Exponential equations to compute mesh centre fluxes.

8. RELATED AND AUXILIARY PROGRAMS

ANISN - produces one-dimensional flux guesses.
SPACETRAN - calculates the neutron or gamma flux at arbitrary points in space exterior to a two-dimensional right circular cylindrical system which as been calculated by the discrete-ordinates code DOT.
DOQDP: A computer program to generate level symmetric quadrature sets.
ADOQ: combines asymmetric quadrature data with symmetric quadrature data to form "biased" quadrature sets.
ESTOQ: a program to compute first-collision sources for eliminating ray effects in two-dimensional Sn calculations.
DASH: a void tracing and Sn Monte Carlo bridging code. Using angular angular fluxes from cylindrical geometry calculation, it calculates angular fluxes on arbitrary cylindrical geometry surfaces outisde the DOT boundaries. It is useful to reduce ray effects.
DOMINO: a general purpose code for coupling discrete ordinates and Monte Carlo radiation transport calculations.
APSAI: a computer code for plotting fluxes and absorption densities generated by the ANISN code.

10. REFERENCES

- W. W. Engle, Jr.:
  'A User's Manual for ANISN'
  Computing Technology Center, Union Carbide Corporation
  Report K-1693 (March 30, 1967).
- N.M. Greene, and C.W. Craven, Jr.:
  'XSDRN, A Discrete Ordinates Spectral Averaging Code'
  ORNL-TM-2500 (July 1969).
- W.A. Rhoades:
  'The ALC1 Program for Cross-Section Library Management'
  ORNL-TM-4015 (December 1972).
- Unpublished Notes for GIP, GRTUNCLE, SPACETRAN, FALSTF, ISOPLOT, PLOTTER,
  PERT-2D, FACT, and DOMINO.
- R. Douglas O'Dell and Raymond E. Alcouffe:
  Transport Calculations for Nuclear Analyses: Theory and Guidelines for
  Effective Use of Transport Codes
  LA-10983-MS and UC-32 (September 1987).
- NEA-CPL:
  Note on DOT3.5 (12 January 1977)
- OECD/NEA:
  Note from the NEA Data Bank (May 1984)
- L. Erradi:
  Corrections Apportees a DOT-3.5/E - Adaptation sur la Machine IBM 4361 (4341)
  VM.

- W.A. Rhoades:
Comments on the DOT 3.5 Version of DOT III (November 1975)
- Utility Network of America:
Program Additions to DOT 3 (July 1975)
- W.A. Rhoades and F.R. Mynatt:
The DOT-III Two-Dimensional Discrete Ordinates Transport Code
ORNL-TM-4280 (September 1973)
- P.A. Read, W.E. Selph and R.J. Cerbone:
DUCT Code Manual, Gulf-RT-10654
- J.T. West:
SORREL (November 1975)
- J.P. Jenal:
Common Symmetric Quadratures and the DOQDP Computer Code (August 1975)
- R.L. Childs:
VIP Input Instructions (November 1976)
- R.L. Childs, D.E. Bartine and W.W. Engle, Jr.:
Perturbation Theory and Sensitivity Analysis for Two-Dimensional Shielding
Calculations, ANS Transactions, Vol. 21, pp. 543-544 (June 1975)
- J.P. Jenal et al.:
The Generation of a Computer Library for Discrete Ordinates Quadrature Sets
ORNL/TM-6023 (September 1977)
- E.T. Tomlinson and R.A. Lillie:
User's Guide and Description of the Perturbation Code Modules DGRAD and TPERT
ORNL/CSD/TM-71 (September 1978)
- E.T. Tomlinson, R.L. Childs, and R.A. Lillie:
DOS Perturbation Modules DGRAD/VIP/TPERT, ORNL/CSD/TM-116 (May 1980)
- J. Pena:
DOT 3.5/E-JEN, Two Dimensional Discrete Ordinates Radiation Transport Code
- P. Barbucci and F. Di Pasquantonio:
Implementation of Exponential Supplementary Equations on DOT-III and DOT 3.5
Codes (Document received November 1977)
- P. Barbucci and F. Di Pasquantonio:
Exponential Supplementary Equations for Sn Methods: The Two-Dimensional Case
Reprint of Paper, Proceedings of Fifth International Conference on Reactor
Shielding, Knoxville, Tennessee (April 18-22, 1977)
- W.A. Rhoades:
Comments on the DOT 3.5 Version of DOT III (November 1975)
- Utility Network of America:
Program Additions to DOT 3 (July 1975)
- W.A. Rhoades and F.R. Mynatt:
The DOT-III Two-Dimensional Discrete Ordinates Transport Code
ORNL-TM-4280 (September 1973)
- P.A. Read, W.E. Selph and R.J. Cerbone:
DUCT Code Manual, Gulf-RT-10654
- J.T. West:
SORREL (November 1975)
- J.P. Jenal:
Common Symmetric Quadratures and the DOQDP Computer Code (August 1975)
- R.L. Childs:
VIP Input Instructions (November 1976)
- R.L. Childs, D.E. Bartine and W.W. Engle, Jr.:
Perturbation Theory and Sensitivity Analysis for Two-Dimensional Shielding
Calculations, ANS Transactions, Vol. 21, pp. 543-544 (June 1975)
- J.P. Jenal et al.:
The Generation of a Computer Library for Discrete Ordinates Quadrature Sets
ORNL/TM-6023 (September 1977)
- E.T. Tomlinson and R.A. Lillie:
User's Guide and Description of the Perturbation Code Modules DGRAD and TPERT
ORNL/CSD/TM-71 (September 1978)
- E.T. Tomlinson, R.L. Childs, and R.A. Lillie:
DOS Perturbation Modules DGRAD/VIP/TPERT, ORNL/CSD/TM-116 (May 1980)
- J. Pena:
DOT 3.5/E-JEN, Two Dimensional Discrete Ordinates Radiation Transport Code
- P. Barbucci and F. Di Pasquantonio:
Implementation of Exponential Supplementary Equations on DOT-III and DOT 3.5
Codes (Document received November 1977)
- P. Barbucci and F. Di Pasquantonio:
Exponential Supplementary Equations for Sn Methods: The Two-Dimensional Case
Reprint of Paper, Proceedings of Fifth International Conference on Reactor
Shielding, Knoxville, Tennessee (April 18-22, 1977)

11. MACHINE REQUIREMENTS

Card input, printed and punched output, and the 3 scratch data sets may be located on any external storage device, as may the 9 optional data sets. A small, but useful, problem can be run in as little as 256k bytes of fast memory. A clock, if available, provides timing data.

13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED:  IBM
360 OS version 16 or later.

14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

This is an improved version of DOT-3 and replaces all previous versions of this code.

15. NAME AND ESTABLISHMENT OF AUTHOR

The DOT code has been developed by Neutron Physics Division
Oak Ridge National Laboratory
Oak Ridge, Tennessee, U.S.A

File name	File description	Records
CCC0276_02.002	DESCRIPTION OF VARIABLES IN COMMON	399
CCC0276_02.003	SOURCE PROGRAM (ORNL FEB-77,F4,EBCDIC)	5946
CCC0276_02.004	HEADER,MESAGE,LOCO,SUBR (F4,EBCDIC)	292
CCC0276_02.005	CNNP SUBROUTINE (FEB-79,F4,EBCDIC)	209
CCC0276_02.006	GRIND SUBROUTINE (F4,EBCDIC)	413
CCC0276_02.007	WWESOL SUBROUTINE (F4,EBCDIC)	124
CCC0276_02.008	GRIND SUBROUTINE (ASSEMBLER,EBCDIC)	1520
CCC0276_02.009	WWESOL SUBROUTINE (ASSEMBLER,EBCDIC)	400
CCC0276_02.010	ALOCAT SUBROUTINE (ASSEMBLER,EBCDIC)	44
CCC0276_02.011	CMVBT SUBROUTINE (ASSEMBLER,EBCDIC)	37
CCC0276_02.012	JOBNUM,ITIME,IOR,IAND,ICLOCK (ASSEMBLER)	236
CCC0276_02.013	CMVBT,ALOCAT,ITIME,IFTIME (F4,EBCDIC)	38
CCC0276_02.014	ERROR MESSAGES	50
CCC0276_02.015	OVERLAY CARDS	27
CCC0276_02.016	SAMPLE PROBLEM INPUT DATA	1027
CCC0276_02.017	SAMPLE PROBLEM PRINTED OUTPUT	7932
CCC0276_02.018	JCL FOR RUNNING DOT-3.5 SAMPLE PROBLEM	193
CCC0276_02.019	UPSCATTER SAMPLE PROB. PRINTED OUTPUT	2678
CCC0276_02.020	VIP SOURCE PROGRAM (F4,EBCDIC)	1086
CCC0276_02.021	BSAM ROUTINES (ASSEMBLER,EBCDIC)	421
CCC0276_02.022	BSAM ROUTINES (F4,EBCDIC)	269
CCC0276_02.023	'FORWARD' FOR VIP SAMPLE PROB. INPUT DATA	386
CCC0276_02.024	'FORWARD' FOR VIP SAMPLE PROB. OUTPUT	3649
CCC0276_02.025	'ADJOINT' FOR VIP SAMPLE PROB. INPUT DATA	381
CCC0276_02.026	'ADJOINT' FOR VIP SAMPLE PROB. OUTPUT	3296
CCC0276_02.027	VIP SAMPLE PROBLEM INPUT DATA	19
CCC0276_02.028	VIP SAMPLE PROBLEM PRINTED OUTPUT	899
CCC0276_02.029	SWANLAKE S. PROB. INPUT(USING VIP OUTPUT)	42
CCC0276_02.030	SWANLAKE S. PROB. PRINTED OUTPUT	304
CCC0276_02.031	JCL FOR DOT-VIP-SWANLAKE RUN	75
CCC0276_02.032	SORREL SOURCE PROGRAM (F4,EBCDIC)	1210
CCC0276_02.033	JCL FOR SORREL SAMPLE PROBLEM	32
CCC0276_02.034	SORREL SAMPLE PROBLEM INPUT DATA	221
CCC0276_02.035	SORREL SAMPLE PROBLEM PRINTED OUTPUT	3729

File name	File description	Records
CCC0276_07.002	DESCRIPTION OF VARIABLES IN COMMON	399
CCC0276_07.003	SOURCE PROGRAM (ORNL FEB-77,F4,EBCDIC)	5946
CCC0276_07.004	HEADER,MESAGE,LOCO (ENEL VERSION,F4,EBCDIC)	312
CCC0276_07.005	CNNP SUBROUTINE (FEB-79,F4,EBCDIC)	209
CCC0276_07.006	GRIND SUBROUTINE (ENEL VERSION,F4,EBCDIC)	466
CCC0276_07.007	WWESOL SUBROUTINE (F4,EBCDIC)	124
CCC0276_07.008	WWESOL SUBROUTINE (ASSEMBLER,EBCDIC)	400
CCC0276_07.009	ALOCAT SUBROUTINE (ASSEMBLER,EBCDIC)	44
CCC0276_07.010	CMVBT SUBROUTINE (ASSEMBLER,EBCDIC)	37
CCC0276_07.011	JOBNUM,ITIME,IOR,IAND,ICLOCK (ASSEMBLER)	236
CCC0276_07.012	CMVBT,ALOCAT,ITIME,IFTIME (F4,EBCDIC)	38
CCC0276_07.013	ERROR MESSAGES	50
CCC0276_07.014	OVERLAY CARDS	27
CCC0276_07.015	SAMPLE PROBLEM INPUT DATA	167
CCC0276_07.016	SAMPLE PROBLEM PRINTED OUTPUT	3299
CCC0276_07.017	JCL FOR RUNNING THE SAMPLE PROBLEM	151
CCC0276_07.018	3-GROUP UPSCATTER PRINTED OUTPUT	1202