Software
SASDIF3DK (Reactor Dynamics and Safety Analysis Codes)

Standard Code Description
 Name of Program:
SASDIF3DK  Computer for Which Program is Designed and Other Machine Version Packages Available:
Mainframe (IBM, CRAY, CDC, etc.), UNIX Workstation (SUN, IBM RISC, HP, SG), or Personal Computer (IBM PC) with FORTRAN Compiler.  Description of Problem Solved:
SASDIF3DK is designed to perform deterministic analysis of coupled neutronics/thermalhydraulic transients in watercooled thermal reactors. Detailed, mechanistic models of steadystate and transient thermal, hydraulic, and neutronic phenomena are employed to describe the response of the reactor core to upsets caused by loss of coolant flow, loss of heat rejection, or control rod motions. The spacetime neutronics capabilities of the DIF3DK computer code are linked to a detailed reactor core thermal hydraulics model, which consists of transient fuelcladdingcoolant heat transfer calculations integrated with a single and twophase water/steam fluid dynamics calculation. A flexible cross section specification capability based on the MACOEF format provides for transient adjustment of DIF3DK group cross sections to reflect neutronic feedback due to fuel, coolant, and moderator temperature and density changes. Transient reactor power distributions calculated with DIF3DK are used to drive the SAS channel thermal hydraulics simulation.  Method of Solution:
In space, each SAS thermalhydraulic channel represents one or more subassemblies with either a single pin model or a multiple pin model. Many channels are employed for a wholecore representation. Heat transfer in each pin is modeled with a twodimensional (r/z) heat conduction equation. Single and twophase coolant thermalhydraulics are simulated with a onedimensional (axial) nonequilibrium, homogenous coolant flow model. The DIF3DK three dimensional nodal spatial kinetics capability is employed, which permits either hexagonalz or xyz Cartesian geometry. The SAS channel thermalhydraulics are solved with an noniterative implicit technique, and the coupling with the implicit DIF3DK spatial kinetics solution is explicit at the time domain level.  Restrictions on the Complexity of the Problems:
Dynamic data storage and retrieval techniques are employed to eliminate restrictions. Problem dimensions are limited only by available computer memory size.  Typical Running Time:
Running times depend on the complexity of the model and the nature of the physical transient. A fewchannel reactor model using only pin heat transfer, single phase coolant dynamics, reactor coolant loops, and reactor point kinetics physical models will generally run orders of magnitude faster than real time on modern computing platforms. A manychannel model with coolant boiling and spatial kinetics will take significantly longer, with running times that depend on problem complexity.  Unusual Features of the Program:
The spatial kinetics and thermalhydraulics models in SASDIF3DK are being developed with sufficient modeling flexibility to permit simulation of coupled transients in domestic U.S. and foreign water cooled reactors, including pressure tube designs moderated by graphite or heavy water.  Related and Auxiliary Programs:
The DIF3DK computer code is fully integrated into the SASDIF3DK program, which retains all the spatial kinetics capabilities of DIF3DK.  Status:
SASDIF3DK is being developed and validated at Argonne National Laboratory in the Nuclear Engineering Division.  References:
 H. S. Khalil, et al., "Coupled Reactor Physics and ThermalHydraulics Computations with the SASDIF3DK Code," Proceedings of the Joint International Conference on Mathematical Methods and Supercomputing for Nuclear Applications, Saratoga Springs, New York, October 59, Vol. 2, pp. 10631071, American Nuclear Society (1997).
 R. B. Turski, et al., "Macroscopic Cross section Generation and Application for Coupled Spatial Kinetics and Thermal Hydraulics Analysis with SASDIF3DK," Proceedings of the Joint International Conference on Mathematical Methods and Supercomputing for Nuclear Applications, Saratoga Springs, New York, October 59, Vol. 2, pp. 10721081, American Nuclear Society (1997).
 T. A. Taiwo, et al., "SASDIF3DK Spatial Kinetics Capability for Thermal Reactor Systems," Proceedings of the Joint International Conference on Mathematical Methods and Supercomputing for Nuclear Applications, Saratoga Springs, New York, October 59, Vol. 2, pp. 10821096, American Nuclear Society (1997).
 F. E. Dunn, et al., "Computationally Efficient Thermal Hydraulics Calculations in the SASDIF3DK Coupled Reactor Physics and Thermal Hydraulics Code," Proceedings of the Joint International Conference on Mathematical Methods and Supercomputing for Nuclear Applications, Saratoga Springs, New York, October 59, Vol. 2, pp. 10971106, American Nuclear Society (1997).
 Machine Requirements:
Memory requirements depend on problem specifications. Disk storage for potentially large ASCII print and binary plotting data storage files is required.  Programming Languages Used:
FORTRAN 77 is used. System dependent routines may be supplied for dynamic memory allocation, timing, and system and user identification.  Operating System:
No special requirements other than a FORTRAN compiler and the usual linker/loader facilities.  Other Programming or Operating Information or Restrictions:
The SASDIF3DK computer code and any related documentation are subject to U.S. DOE Applied Technology regulations.  Name and Establishment of Author(s) or Contributor(s):
 J. E. Cahalan
Nuclear Engineering Division
Argonne National Laboratory
9700 South Cass Avenue
Argonne, Illinois 60439
 J. E. Cahalan
 Materials Available:
Because of its developmental nature, SASDIF3DK is not being distributed.  Sponsor:
U.S. Department of Energy, Office of Nuclear Energy, Science, and Technology.
Last Modified: Wed, April 20, 2016 9:51 AM