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TRACE Plug-in

The TRAC/RELAP Advanced Computational Engine (TRACE) code is the latest in a series of advanced, best-estimate reactor systems codes developed by the U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. It is the product of a long term effort to combine the capabilities of the NRC’s four main systems codes (TRAC-P, TRAC-B, RELAP5 and RAMONA) into one modernized computational tool.

The TRACE plug-in requires installation of the PARCS plug-in. Please note that the PARCS plug-in will automatically be selected for installation with the TRACE plug-in if you choose to install SNAP directly from the web site. If you download the installation packages to a folder for later installation, the TRACE plug-in will not be available for installation unless you include the PARCS plug-in in your download.

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

Change Log

Version 3.8.6 - Released 11/21/2017:

  • The TRACE plug-in was updated to include experimental support for the generation of parallel or "Multi-Task" input files as part of a Job Stream submission. This new feature will automatically split a TRACE model into multiple input files based on user-specified sets of components. The splitting process will also create any EXTERIOR components required in each of the generated parallel input files. Note that this feature is only available for the developmental version of patch 5 ("V 5.0 P5 Dev").
    The contents of a Parallel Task Set can be viewed by using the "Show ASCII" right-click pop-up menu item on that task set in the Navigator. This will show the ASCII input files that will be for each of the Parallel Tasks defined for that set. A comment header will be included at the top of each section of the file indicating which task is being written.
  • The SNAP Job Stream support for TRACE ECI and the TRACE ECI driver has been updated to support multiple application types and locations. Note that application Setup Types (in the Config Tool) other than "None" are incompatible with ECI. This is due to the fact that the application location used with setup types other than "None" is not known for a given task until that task is already executing.
  • A sorting issue was resolved that caused TRACE to fail during initialization for some ECI calculations, if the job step number of the "central process" was higher than any other step in the task set.
  • The editing dialogs for tabular data in most TRACE components have updated to provide a more intuitive user interface. The copy/paste behavior has been updated to behave like a spreadsheet. The table was updated to remove the automatic sort behavior. A sort button has been added which is only enabled if the independent variable values are out of order. Pressing the sort button will reorder the table rows so the independent variable values are in ascending order. Independent variable values that are less than a preceding value will be displayed in red font.
  • The valve component ASCII import logic has been updated to resolve an issue which would prevent importing a valve with a wall power table.
  • The wall power table data load-format prefix comment has been resized to 9 characters to match the rest of the load-format prefixes used by 1D hydraulics.
  • The Control block ASCII import logic has been updated to resolve an issue where the second control block input would move to the first control block input location if the first location is set to 0 in the ASCII input file.
  • The channel component has been updated to prevent an error message from being displayed indicating that the inside radius has not been set. This field is no longer used for channel components.
  • The heat structure / FRAPCON fuel rod mapping dialog has been updated to allow exporting a heat structure mapping, to include an Apply button, and a top-down view of the vessel. The apply button will apply the FRAPCON fuel rod data to all of the mapped heat structures in the model. The top-down view of the vessel will highlight the planar cell where the selected fuel rod heat structure exists.
  • The heat structure / FRAPCON fuel rod importer has been updated to support output generated from either FRAPCON or FAST.
  • The TRACE Job Stream Step has been updated to include the PARCS restart input for all coupled cases. The input is required if the PARCS model is set to explicitly define the restart file in the Job Stream.
  • The signal variable validation logic has been updated to report an error when a heat structure signal variable is connected to a 1D hydraulic component if that component does not have an active pipe wall.
  • The pump validation logic has been updated to report an error when the rated values or alternate inertia are less than or equal to 0.0. Additionally, the Alternate Speed Cuton value will report an error if it is not between the 0.0 and the Rated Speed value.
  • The Function of 2 or more Variables has been updated to resolve an issue which would prevent adding entries to an independent variable that contains no entries.