Recent News
SNAP Version 4.0.3 Released
April 29, 2022
AptPlot 8.0.1 Updated
April 29, 2022
PyPost 4.0.1 Released
October 29, 2021

Symbolic Nuclear Analysis Package

The Symbolic Nuclear Analysis Package (SNAP) consists of a suite of integrated applications designed to simplify the process of performing engineering analysis. SNAP is built on the Common Application Framework for Engineering Analysis (CAFEAN) which provides a highly flexible framework for creating and editing input for engineering analysis codes as well as extensive functionality for submitting, monitoring, and interacting with the codes.

Important Notice Concerning Log4J Vulnerability (CVE-2021-44228): The Log4j utility is included in earlier versions of AptPlot and SNAP. We recommend that you promptly delete any earlier versions of AptPlot or SNAP that you may have installed and update to the latest version of this software. AptPlot Version 8.0 which is now included as a plug-in to SNAP Version 4.0.1 was released in October 2021.  These versions of AptPlot and SNAP do not include the Log4J utility. 

Download SNAP

Getting Started

A guide to downloading and installing SNAP and its prerequisite software.


Users' manuals, on-line instruction, tutorials, and other SNAP related materials.

SNAP Plug-ins

Find information about the various SNAP plug-ins available to users.

Technical Support

Technical support is available to CAMP members, NRC contractors and SNAP User's Group members.

Change Log

SNAP 4.0.3 - Released 4/29/2022:

  • An issue has been resolved that prevents the creation of new Animation models.
  • An issue has been resolved that would cause the Find Components dialog to re-open when changing between models, or graphically editing a restart case.
  • The logic for opening views from MED files after closing a restart case has been modified to preserve view order.
  • The AptPlot Batch script editing dialog has been updated to correctly identify AptPlot VARS file types from the "READVARS" command.
  • The Apt Plot job step has been modified to resolve an issue which would prevent the “Delete Upon Completion” option from setting correctly when applied to an input file.
  • Added support for the batch_command function in Python directed job streams. This command executes a single Model Editor batch command.
  • The model read logic has been updated to gracefully handle the unlikely scenario where a view has a conflicting primary key when opening a legacy model.
  • If a model contains duplicated primary key values other than a view, the model will fail to open with a reported error message. Contact APT for instructions on correcting corrupted models.
  • The Python directed job stream samples have been updated to match the current library methods.
  • The Python Script job step sample for writing an output file has been corrected.
  • Logic was added to no longer attempt to process application definitions in the user temp directory. This prevents an issue where the read logic did not have read permissions to files in the directory, causing the global configuration initialization to fail.
  • The Diff/Merge Library was updated to support comparison and merge for TRACE heat structures.

see older releases