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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 6.6.3 - Released 2/28/2022:

  • The python test harness has been changed to allow generic calls to different plug-ins instead of being hardcoded for RELAP.
  • Changes made to the RELAP library to support the latest version of the Diff/Merge plug-in.
  • The value based comparison / merge behavior for time dependent volumes has been updated to prevent merging of tabular data and display an information message when one time dependent volume uses tabular data, and the other uses control systems.
  • The value based comparison / merge behavior for time dependent junctions has been updated to resolve an issue where comparing a mass flow TDJ against a velocity TDJ would match the velocity arrays to the mass flow arrays when they should be identified as orphans (only one side).
  • The value based comparison / merge behavior for control blocks has been updated to resolve a number of issues:
    • An issue has been resolved that would prevent comparing two control blocks where the left control block has fewer connections than the right control block.
    • The input connections merge behavior for control blocks was updated to prevent merging input connections beyond the expected number of input connections for the control block type.
    • The merge behavior for control blocks was updated to prevent attempting to merge input connections into a control block that does not support any input connections.
  • Logical Trips, Variable Trips, Control Blocks, General Tables, and Interactive Variables have been updated to support value based comparison and merge of differences.
  • The Pump and Compressor properties have been updated to allow setting their inlet and outlet connections through the Property View. The ASCII contexts for the inlet and outlet connections now highlight the appropriate property view property when edited.
  • Accumulators have been updated to allow setting their inlet connections through the Property View. The ASCII context for the inlet connection information now highlights the "Inlet" property view property when edited.
  • The display name for the property of a Compressor that controls whether or not the outlet junction is included with the compressor component has been changed to "Outlet Option".
  • The responsiveness of the Model Editor user interface has been improved for models with a very large number of signal variables.
  • The Typpwr sample has been updated to include a sample Job Stream.
  • The RELAP ASCII view has been updated to prevent the warning message indicating a line exceeds 80 columns from appearing if that line includes a Unix substitution variable name.
  • The editing dialog for hydraulic connections has been updated to resolve an issue that prevented setting an axial cell number by typing in a value.
  • The value based comparison and merge capabilities have been extended to all 1D hydraulic components and CCFL models. The list of components that support this behavior includes: 
    • Annulus, Pressurizer, Valve, Single Flexible Wall, Accumulator, Branch, ECC Mixer, Jet Mixer, Feedwater Heater, Pump, Compressor, Separator, Turbine, Time-dependent volume, single volume multiple junction, multiple flexible wall components, and CCFL.
  • The value based comparison / merge behavior has been updated prevent merging sub-element floating point properties that reference an orphan numeric variable. Numeric variables must be merged into the target model before merging properties.

more...