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The Central Registry and DOE/EH Toolbox Codes

The DOE Central Registry provides information about DOE safety software toolbox codes.  The toolbox codes are, in principle, a small number of standard computer codes having widespread safety software applications.

The codes are routinely used by DOE and their contractors to perform calculations and develop data used to establish the safety basis for DOE facilities and operations, and to support the variety of safety analyses and safety evaluations developed for these facilities.

DOE conducted a survey of design codes currently in use to determine which should be included in an initial set of toolbox codes.  Initially, six codes were identified as toolbox codes:  ALOHA, CFAST, EPICODE, GENII, MACCS2, and MELCOR. Two other codes, IMBA and HotSpot, were later added to the toolbox.  The following list provides summary information on the version of each code in the tool and the code owner.

ALOHA, V5.2.3., National Oceanic and Atmospheric Administration (NOAA)

CFAST, V3.1.7 and 5.1.1, National Institute of Standards and Technology (NIST)

EPIcode, V7.0, Homann Associates, Inc.

GENII, Version 2.1 being tested by EPA and NRC, Pacific Northwest National Laboratory (PNNL)

IMBA, IMBA Expert ™ USDOE Edition version 4.0.28, UK Health Protection Agency (HPA)

MACCS2, V1.13.1, Sandia National Laboratory (SNL)


HotSpot, Lawrence Livermore National Laboratory (LLNL)

Prior to inclusion into the Central Registry, an evaluation of each code, referred to as a gap analysis, is conducted to identify any "gaps" between a code’s SQA program and DOE's requirements for safety software.  In addition, code-specific guidance reports identify applicable regimes in accident analysis, default inputs, and special conditions for using the toolbox codes for DOE applications.  These documents as well as general information are available through the links provided above.

Most of the toolbox codes were developed outside of DOE (e.g., by the private sector or by other Federal agencies).  Access to the toolbox codes or their use is subject to agreements, conditions, and restrictions established by the code owners or governing federal agencies.

Although use of the Central Registry toolbox codes is not mandatory, using the codes offer a number of advantages to the DOE and its contractors.  These advantages include:

  • Gap analysis evaluations provide valuable information as to the quality of the code
  • The evaluations extend beyond the DOE SQA criteria to review the code's capability to properly perform safety basis calculations
  • DOE-specific guidance documents identify limitations and vulnerabilities not readily found in other code documentation
  • A reduction in the paperwork needed to support and justify the use of the toolbox code
  • Continual monitoring and communication to DOE users of new code features, updates, and corrections of defects

The toolbox code owners are responsible for ensuring that the codes are maintained in accordance with established requirements.  DOE/HSS strives to work closely with the code owners to ensure that adequate technical support and training are available to support SQA-related activities.