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Symbolic Nuclear Analysis Package (SNAP)

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. SNAP is developed by Applied Programming Technology (APT), Inc. and is sponsored by the NRC. It provides the RADionuclide, Transport, Removal, and Dose Estimation (RADTRAD) user with a graphical user interface with pre– and post–processor capabilities allowing users to develop RADTRAD input decks.

RADionuclide, Transport, Removal, and Dose Estimation (RADTRAD)

The RADionuclide, Transport, Removal, and Dose Estimation (RADTRAD) code is a licensing analysis code used to show compliance with nuclear plant siting criteria for the site boundary radiation doses at the Exclusion Area Boundary (EAB) and the Low Population Zone (LPZ) and to assess the occupational radiation doses in the control room (CR) and /or Emergency Offsite Facility for various loss-of-coolant accidents (LOCA) and non-LOCA design basis accidents (DBAs). RADTRAD uses a combination of tables and numerical models of source term reduction phenomena to determine the time-dependent dose at the CR, EAB and LPZ for given DBA scenarios.
  • SNAP/RADTRAD (RADTRAD-AC version 5.0), which was issued in February 2020, is the NRC developed Java version of the RADTRAD code with additional features and options. Some of these include additional features and options include the reactor coolant system (RCS) activity calculator, a larger radionuclide database from ICRP-38 (838 available nuclides), and the ability for the user to model alternative source term (AST) non-LOCA DBAs described in Regulatory Guide 1.183 (RG 1.183).


The RADTRAD Development Team

The SNAP Development Team
SNAP Project Manager

The RAMP Project Manager