Cyclus is the next-generation agent-based nuclear fuel cycle simulator, providing flexibility to users and developers through a dynamic resource exchange solver and plug-in, user-developed agent framework.

The goal of Cyclus is to enable a broad spectrum of fuel cycle simulation while providing a low barrier to entry for new users and agent developers. Cyclus engages with potential module developers and encourages them to join a vibrant community in an expanding ecosystem. Users and developers are always welcome and encouraged to use or contribute to the Cyclus project.

The Cyclus project repository is located at

Quick Start

Learn More


May 4, 2024: Cyclus v1.6.0 is released

April 29, 2024: FY 24 Funding for Cyclus

January 14, 2020: Cyclus v1.5.5 is released

June 1, 2018: Cyclus Newsletter Spring 2018

October 6, 2017: Cyclus Newsletter Fall 2017!

December 13, 2016: Cyclus v1.5.0 is released

July 6-8, 2016: Technical workshop on Dynamic Fuel Cycle in Paris, France

August 13, 2015: Cyclus included in FY2016 workscopes for the NEUP program

July 21-24, 2015: Joint workshop with CLASS project held in Madison, WI

June 10, 2015: First Cyclus user tutorial and developer tutorial are held at the 2015 ANS Annual Meeting in San Antonio, TX

June 7, 2015: Cyclus v1.3.1 is released

Try It – Out-of-Service

The web-based capability to run Cyclus is out of service. Please check out our user start guide to get other ways to try Cyclus. Feel free to reach out using our Users’ mailing list and forum if you need help.

Contact Us


You can find our amazing contributors through their GitHub contributions for each of the projects:


Support for this research has included funding received from: