RSICC Home Page SKETCH-N 1.0

RSICC CODE PACKAGE CCC-808

1.         NAME AND TITLE

SKETCH-N 1.0:  Solve Neutron Diffusion Equations of Steady-State and Kinetics Problems.

 

AUXILIAR PROGRAMS

PVM library is used for the interface module of the code.  The interface module requires PVM be installed on the  computer. The PVM is a public domain software available from NETLIB http://www.epm.ornl.gov/pvm/pvm_home.html.

2.         CONTRIBUTORS

Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 Japan through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

3.         CODING LANGUAGE AND COMPUTER

Fortran 77 and 90; PC Windows NT/Windows, UNIX Workstations (C00808MNYCP00).

4.         NATURE OF PROBLEM SOLVED

The SKETCH-N code solves neutron diffusion equations in x-y-z geometry for steady-state and neutron kinetics problems. The code can treat an arbitrary number of neutron energy groups and delayed neutron precursors.

5.         METHOD OF SOLUTION

The polynomial, semi-analytic and analytic nodal methods based on the nonlinear iteration procedure are used for spatial discretization of diffusion equations. The time integration of the neutron kinetics problem is performed by a fully implicit scheme with an analytical treatment of the delayed neutron precursors. The steady-state eigenvalue problems are solved by inverse iterations with Wielandt shift; the Chebyshev adaptive acceleration procedure is used for the neutron kinetics problem. The block symmetric Gauss-Seidel pre-conditioner is applied in the both iterative methods. The flux-weighting homogenization procedure is used for partially-rodded nodes to minimize the rod cusping effect. Simple one-phase model of the thermal-hydraulics of fuel assembly is included in the code. The code also has an interface module for a coupling with transient analysis codes such as TRAC. The interface module performs a data exchange between the codes, synchronizes the time stepping and maps the neutronics data onto thermal-hydraulics spatial mesh and vice versa. The interface module is based on the message-passing library PVM (Parallel Virtual Machine).

6.         RESTRICTIONS OR LIMITATIONS

The code can treat the neutron diffusion problems in Cartesian geometry Few-group macro cross-sections and their dependencies are provided by a c ode user. The code does not have fuel burn-up modeling capabilities. An external thermal-hydraulics code is generally required for the calculation of the "real-life" problems.

 

Dimensions of a problem are specified as parameters in the include files, the code should be recompiled when the problem dimensions are changed. The code has PVM-based interface module developed for a coupling with transient thermal-hydraulics codes. The interface model has been used for a coupling of the SKETCH-N code with the J-TRAC (TRAC-PF1) and TRAC-BF1 codes.

 

The code has been verified by solving the steady-state and neutron kinetics benchmark problems. The coupled J-TRAC/SKETCH-N code system has been verified against NEACRP PWR rod ejection and rod withdrawal benchmark. NEACRP BWR cold water injection benchmark has been used for verification of the TRAC-BF1/SKETCH-N system.

7.         TYPICAL RUNNING TIME

The running time of the full-core case C1 of the PWR NEACRP rod ejection benchmark (2 neutron energy groups, 6 groups of the delayed neutron precursors, 884x18 neutronics nodes, 910 time steps) is 68 minutes on Sun UltraSPARC I (143 MHz) with an internal thermal hydraulics model.

8.         COMPUTER HARDWARE REQUIREMENTS

A workstation under UNIX, Windows NT or Windows.

9.         COMPUTER SOFTWARE REQUIREMENTS

UNIX, Windows NT.  The package is distributed as received from the NEADB.

10.       REFERENCES

10.a) Included Documentation:

- Vyacheslav G. Zimin, “SKETCH-N: A Nodal Neutron Diffusion Code for Solving Steady-State and Kinetics Problem,” Vol. I, Model Description (2000).

- Vyacheslav G. Zimin, “SKETCH-N: A Nodal Neutron Diffusion Code for Solving Steady-State and Kinetics Problem,” Vol. II, User's Guide (Sept. 2000).


10.b) Background References:

- Vyacheslav G. Zimin and Hisashi Ninokata, “Nodal Neutron Kinetics Code SKETCH-N for LWR Analysis,” Proc. 1998 Annual Meting of AESJ, Osaka, 1998, March 26-28, G15.

- Vyacheslav G. Zimin, Hideaki Asaka, Yoshinari Anoda and Masaki Enomoto, “Coupling of the Transient Analysis Code J-TRAC with 3D Neutron Kinetics Code SKETCH-N,” Proc. 1999 Annual Meeting of AESJ, Hiroshima, March 22-24, I8.

- Vyacheslav G. Zimin, Hideaki Asaka, Yoshinari Anoda, Masaki Enomoto, “Verification of J-TRAC Code With 3D Neutron Kinetics Model SKETCH-N for PWR Rod Ejection Analysis,” Proc. of the 9th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH 9), San Francisco, California, October 3-8, 1999.

- Hideaki Asaka, Vyacheslav G. Zimin, Tadashi Iguchi and Yoshinari Anoda, “Coupling of the Thermal-Hydraulic TRAC Codes with 3D Neutron Kinetics Code SKETCH-N (2000)”, Proc. of the OECD/CSNI Workshop on Advanced Thermal-Hydraulic and Neutronics Codes, Current and Future Applications, Barcelona, Spain, 10-13 April, 2000, vol2 pp.1-15.

- Vyacheslav G. Zimin, Hisashi Ninokata, Leonid R. Pogosbekyan, “Polynomial and Semi-Analytic Nodal Methods for Nonlinear Iteration Procedure,” Proc. of the Int. Conf. on the Physics of Nuclear Science and Technology (PHYSOR-98), October 5-8, 1998, Long Island, New York, American Nuclear Society vol. 2, pp. 994-1002.

- Vyacheslav G. Zimin, Hideaki Asaka, Yoshinari Anoda, Elja Kaloinen, RiittaKyrki-Rajamaki. “Analysis of NEACRP 3D BWR Core Transient Benchmark,” Proc. of the 4th Intl. Conf. on Supercomputing in Nuclear Application (SNA 2000) September 4-7, 2000, Tokyo, Japan.

11.       CONTENTS OF CODE PACKAGE

This package consists of one DVD-ROM with the SKETCH-N 1.0 source code, sample input and output files for LWR Benchmarks, steady-state 2D four-group Koeberg PWR benchmarks, 3D NEACRP PWR rod ejection benchmark case A1, 3D NEACRP BWR cold water injection benchmark, along with the documentation listed above.

12.       DATE OF ABSTRACT

November 2013.


KEYWORDS:      KINETICS, NEUTRON DIFFUSION EQUATION, NODAL METHOD, NONLINEAR, THREE-DIMENSIONAL, TRANSIENTS