|Program name||Package id||Status||Status date|
|Package ID||Orig. computer||Test computer|
|NEA-1577/01||SUN W.S.,PC Windows||PC Pentium III,DEC ALPHA W.S.|
The polynomial, semi-analytic and analytic nodal methods based on the nonlinear iteration procedure can be used for spatial discretisation 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 preconditioner is applied in the both iterative methods. The flux-weighting homogenisation procedure is used for partially-rodded nodes to minimize a 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, synchronises a 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).
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.
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.
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 wit the J-TRAC (TRAC-PF1) and TRAC-BF1 codes.
|Package ID||Status date||Status|
|NEA-1577/01||14-MAR-2002||Tested at NEADB|
|Package ID||Computer language|
The interface module requires PVM installed on a computer. The PVM is a public domain software available from NETLIB http://www.epm.ornl.gov/pvm/pvm_home.html
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.
Keywords: kinetics, neutron diffusion equation, nodal method, nonlinear, three-dimensional, transients.