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SCALE is a comprehensive modeling and simulation suite for nuclear safety analysis and design developed and maintained by Oak Ridge National Laboratory under contract with the U.S. Nuclear Regulatory Commission, U.S. Department of Energy, and the National Nuclear Security Administration to perform reactor physics, criticality safety, radiation shielding, and spent fuel characterization for nuclear facilities and transportation/storage package designs.

The 6th SCALE Users’ Group Workshop (hybrid event) was held April 27-29, 2022. A link to the web page is found here.

The SCALE website contains the following major sections:

  • Overview: additional details on SCALE capabilities.
  • Releases: details on SCALE releases.
  • Training: information on our upcoming training courses.
  • References: links to downloadable scientific journal articles and reports with bibtex for easy citing of SCALE references. 
  • Support: how to get help with SCALE, including presentations, annual reports, newsletters, and QA documents.  

Please direct any inquiries to

The SCALE 2022 Calendar is now available.

For general SCALE references, please cite the latest manual.

W. A. Wieselquist, R. A. Lefebvre, and M. A. Jessee, Eds., SCALE Code System, ORNL/TM-2005/39, Version 6.2.4, Oak Ridge National Laboratory, Oak Ridge, TN (2020). 

For more specific references see