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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 6.0.4 - Released 10/25/2018:

  • Various optimizations were made to the RELAP plug-in's validation display and context sensitive ASCII export routines.
  • An issue has been resolved that would cause newly created heat structure cells to have the same cell index when added through the cells / surface BC's editing dialog.
  • An issue with radiation enclosure editors has been updated to prevent an error during multiple component selection in the Navigator.
  • The general table component has been updated to verify the number of rows in a referenced table variable.
  • The multi-dimensional component was updated to change the wording of the error message that appears when 3D Momentum is used and one or more junctions have a non-zero momentum flux flag (s-flag). Additionally this check is now performed when the Dimension Flag property is disabled, defaulting to use 3D Momentum.
  • The meta-data comment data for table variable references has been updated to only write the bounding comment cards during a Unix substitution export when the variable name begins with a '$'. This includes restart cases where numerics are preserved, and resource exports.

Please Note: The following issues are still under development:

  • The model options sub-system integration logic has been updated to preserve kinetics time step control system cross references.
  • The logic that generates the variable header at the top of the file when exporting a restart case has been updated to resolve an issue where the delimiting text between the name and value were lost.
  • The restart case export logic was updated to support the Include Unix Subst. Vars. property of RELAP job stream model nodes when determining what to write for embedded tabular variable values.
  • The following updates have been made to the external cross reference reports generated during a sub-system integration:
    • Model options print controls, volume list starting cell location has been updated to "Print Control Start Volume"
    • Pressurizer surge line and sprayer hydraulic connections identify themselves as Surge Line or Sprayer in the Location field.
  • An issue was resolved that prevented the Target Sub-System references of Integration Case Definitions from being properly reconnected after a sub-system integration.
  • The restart case export logic was updated to handle the situation where a restart case includes a table variable reference, and the table variable references other variables inside the table cells.'
  • An issue was resolved that prevented some cross-references to control systems from being properly reconnected during a sub-system import.
  • The reactor kinetics ASCII export logic for the volume weighting and heat weighting tables have been updated to correct the compression behavior when exporting more than 99 rows. The compression algorithm compresses as densely as possible when more than 99 entries are encountered. If the compression algorithm cannot reduce the number of cards below 100, and error message will be reported during ASCII export.
  • The kinetics component has been updated to prevent error messages on the volume or heat weight factor tables from being reported when the underlying table entries are defined using a table variable reference.
  • The heat weighting factor table in reactor kinetics now includes a table variable reference block end tag when the heat weighting factor table is defined using a table reference.
  • The reactor kinetics has been updated to support references to table variables with more than 99 rows for volume weighting factor tables and heat weighting factor tables. The export logic will build an increment value that allows using the expanded format for extra data sets on a card when the table contains more than 99 rows. When exporting the placeholder text for UNIX substitution variables, only 99 rows will be exported.