Recent News
SNAP Version 2.6.1 Released
February 28, 2018
AptPlot 6.8.0 Updated
February 19, 2018
PyPost 1.3.3 Released
February 19, 2018

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 5.0.1 - Released 2/28/2018:

  • The RST-Plot Control and Action property in Model Options has been updated to include the MBINARY option for RELAP 5D v 4.0 or greater.
  • The fluid types supported by hydraulic systems have been updated to include the DOWA and R134A types.
  • The Single flexible wall component has been updated to rename the General Table property to “Wall Stiffness Table”.
  • The following RELAP5-3D heat signal variables were added: HTMWPOW, HTMWRQ.
  • An issue has been resolved which caused summer control blocks connected to resupplied control blocks in a restart case to lose their scale factors.
  • An issue has been resolved that was creating multiple undo steps when modifying Hydraulic Diameter and Wall Roughness for a Time Dependent Volume.
  • An issue has been resolved that would cause an error when plotting or animating RELAP variables that are not explicitly recognized by SNAP.
  • The RELAP5-3D PIB plot file format reading logic used in the SNAP MATLAB library and RELAP5 plug-in animation has been updated to significantly improve the performance of large files.
  • The Multiple junction model notebook export has been updated prevent the two geometry tables from merging together in DOCX format.
  • The ASCII import of Unix substitution variables was updated to resolve an issue which caused the calculated parameter for cell geometry (area, length, or volume) to be incorrectly set to the field defined by a variable after import.
  • The ASCII import of a Relief valve with Unix substitution variables has been updated to set the activation state of the Bellows Pressure property correctly when it is defined using a Unix Substitution variable.
  • The ASCII export logic with Unix substitution support has been updated to include the hydraulic diameter card (e.g. CCC0110) when the hydraulic diameter is defined using a Unix Substitution variable, even if the value of that variable is set to 0.0.
  • The ASCII export logic with Unix substitution support has been updated to include the junction flow area cards when the area is defined using a Unix Substitution variable even if that variable has a value of 0.0.
  • The Reactor Kinetics component has been updated to disable the "Reactor Time" property when the Power History Table has any rows.
  • The Model Notebook export logic for the Valve component was updated to include the Face Placement table.
  • The reactor kinetics model notebook export was updated to ensure that the sets of detector data are distinct from one another.
  • An issue has been resolved with pipe, pressurizer, and annulus, which caused the option that indicates whether the area, length, or volume calculation flag should be specified by cell to be lost when saved. 

Please Note: The following issues are still under development:

  • The dialog for selecting components to include in a restart has been updated to include filters for limiting the displayed components and to allow sorting the displayed components by type, number or name.
  • The Separator 2D VOVER/VUNDER table shading in the model notebook has been corrected to be consistent with other tables.
  • The RELAP5 plug-in was updated to ensure that modifying the following properties updates the ownership value and clears the reviewer value:

    Numerics Variables: Name
    Model Options: Code Version, Developmental Options, Minor Edit Requests, Expanded Plots, Validation Options, and Extra Deck Data.