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RELAP5/RELAP5-3D Plug-in

The RELAP5 plug-in was designed to supports multiple versions of RELAP5 including RELAP5/MOD3.3 and RELAP5-3D versions 2.2, 2.3, 2.4, 2.6, 4.0 and 4.3. This plug-in is available to SNAP User's Group (SUG) members.

The RELAP5-3D© code was developed for best-estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems.

The RELAP5 Plug-in User's Manual provides instructions for working with RELAP5 models in SNAP. This Manual is also available as a searchable help set in SNAP.

Change Log

Version 6.0.0 - Released 8/18/2018:

  • The heat structure boundary condition type editor has been updated to correct the label for a controlled heat flux.
  • The control number format flag editor was updated to refresh all of the open dialogs when the value is changed.

Please Note: The following issues are still under development:

  • Several issues were resolved in the RELAP plug-in sub-system integration process that prevented the following cross-references from being properly discovered and reconnected:
    • Heat Structure component Gap Volume and Radial Geometry Node Location
    • Interactive Variable component Variable Request Code
    • Model Options component Self Initialization Options
    • Prizer component Surgeline Junction and Spray Junction
    • Model Options component Junction references in Print Controls
    • all Radiation Enclosure cross-references
    • all RN Species component cross-references
  • The "Exportable" and "Imported" properties of a sub-system component have been removed. These properties were intended to be used by the sub-system integration system to ensure that only "Exportable" sub-systems could be imported into other models and only "Imported" sub-systems could be directly updated. These restrictions proved to be cumbersome and unintuitive. Any sub-system can now be used in a sub-system integration.
  • A sub-system integration command has been added to allow integrations to be performed via the batch command interface. This will make the integration process available to other applications that either load the Model Editor as a library or communicate via batch command. The SUB_SYS_IMPORT command will update the sub-system with given name in either the current model or the model with the given label.
  • SUB_SYS_IMPORT <Mn> "[target sub-system name]" "[filename]" "[source sub-system name]"
  • Any messages reported during the integration process will be displayed in the Message Window (if one is available) and in the Model Editor’s screen file. These messages include those that would be reported if the integration was performed in the user interface as well as new error messages reported by the SUB_SYS_IMPORT command.
  • A new Integration Case component has been added to the SNAP core and enabled for the RELAP and TRACE plug-ins. The Integration Case component represents a pre-defined set of sub-system integrations performed in the specified order. The set of integrations will be performed when the case is graphically edited (much like restart cases) and when the case is exported to a local file.
  • The "EXPORT CASE" command has been updated to support sub-system integration using the Integration Case component. This will allow integration cases to be applied and the full model exported to a file in batch mode using the following syntax:
    • RELAP EXPORT CASE <label> "[case name]" "[filename]"
  • The RELAP-specific sub-system integration system was updated to eliminate several edge cases that could cause drawn components in the master model to be lost when updating views after an integration.
  • Support for the SNAP Validation display has been added to the RELAP plug-in. This display includes the contents of the current model in ASCII format (as shown in the ASCII Viewer) and a toolbar that indicates the current cursor location and a brief description of the input at that location. Clicking on a supported portion of the input will update the cursor location and enable the "Open Editor" toolbar button. Pressing the "Open Editor" button will open the graphical editor corresponding to the current cursor location.
  • Note that the ASCII Viewer displayed by the "Show ASCII" feature also includes the Validation Display selection and "Open Editor" features.
  • The ASCII import logic has been updated to preserve table variable references for general tables, heat structure source data and kinetics weighting tables. These references will be preserved for Unix Substitution, restart cases while preserving numerics and resource exports.
  • Reactor kinetics has been updated to support using a table variable to define the contents of the heat weighting factor table.