Software

DASSH (Thermal-Hydraulic Codes)

Standard Code Description

1. Name of Program:
   Ducted Assembly Steady-State Heat Equation software (DASSH)
2. Computer for Which Program is Designed and Other Machine Version Packages Available:
   Any workstation that runs the ARC code suite, developed and maintained at Argonne National Laboratory.
3. Description of Problem or Function:
   The coolant temperature distribution in fast reactors is critical to reactor design, informing core restraint and flow orificing calculations. DASSH is being developed at Argonne to perform steady-state thermal fluids calculations to determine coolant flow and temperature distributions in ducted, hexagonally arranged assemblies typical of liquid metal fast reactors. DASSH is a reduced-order subchannel code descended from the SUPERENERGY family of codes developed in the 1970s and revised at Argonne in the 1990s. Relative to its predecessors, DASSH reduces the number of approximations and assumptions required and enables greater flexibility through user specification of built-in or custom correlations and material properties. DASSH interfaces with the DIF3D-VARIANT neutronics software from the ARC code suite to model the distribution of thermal power in the core, including neutron and gamma heating in the assembly structural materials.
4. Restrictions on the Complexity of the Problems:
   DASSH assumes steady-state turbulent flow under forced convection. Problems where natural circulation is relevant, such as in assemblies with low flow rates, are not currently supported. DASSH is being built initially to interface with the ARC code suite, but in the future may be linked to other neutronics codes, such as MCNP.
5. Typical Running Time:
   The code that predates DASSH, called SE2-ANL, runs relatively quickly, returning full-core temperature distributions in minutes. It is envisioned that DASSH will achieve comparable running time. The ARC codes that DASSH relies on can take longer, depending on the size and complexity of the problem.
6. Unusual Features of the Program:
   As compared to its predecessors, DASSH allows the user to specify their own correlations in input tables, enabling the software to (a) be applied to highly specific problems, and (b) remain relevant as new correlations are measured.
7. Related and Auxiliary Programs:
   DASSH is currently being developed to interface with the ARC code suite developed and maintained at Argonne National Laboratory. DASSH relies on DIF3D-VARIANT and GAMSOR for neutron and gamma power distributions.
8. Status:
   DASSH is currently under development, with version v1.0 planned for release in FY20. The distribution is expected to be open source. Newer versions, including interfaces to additional neutronics software, will be developed and made available in the future.
9. References:
10. Machine Requirements:
    Requirements are driven by the applications run with the ARC code suite.
    
11. Programming Languages Used:
    Python.
    
12. Operating System:
    No special requirements are made on the operating system: Windows/Linux/MacOS
13. Other Programming or Operating Information or Restrictions:
    
14. Name and Establishment of Author or Contributor:
    • M. Atz, Argonne National Laboratory
      
15. Materials Available:
    
16. Sponsor:
    U.S. Department of Energy, Office of Nuclear Energy

Contact:

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Last Modified: Wed, June 10, 2020 3:03 PM