Open Architecture and Modular Paradigm of CYCLUS , a Fuel Cycle Simulation Code

The CYCLUS project at the University of Wisconsin Madison is the result of lessons learned from experience with previous nuclear fuel cycle simulation platforms. The modeling paradigm follows the transacation of discrete quanta of material among discrete facilities, arranged in a geographic and institutional framework, and trading in flexible markets. Key concepts in the design of CYCLUS include open access to the simulation engine, modularity with regard to functionality, and relevance to both scientific and policy analyses. The combination of modular encapsulation within the software architecture and an open development paradigm allows for a balance between collaboration at multiple levels of simulation detail and security of proprietary or sensitive data. When comparing different nuclear fuel cycle concepts, it can be a challenge to find any two systems analyses that compare across a common set of metrics with a similar set of underlying assumptions. Each analysis is likely to focus on a set of metrics that are of interest to the team performing the analysis and involve both implicit and explicit assumptions and constraints about the behavior of the fuel cycle system. While a strict prescription of these metrics, assumptions and constraints could be proposed for comparison purposes, another solution is to provide a systems analysis simulation tool that provides sufficient modularity, extensibility and open access, that it can be a basis for harmonzing to a common set. If it becomes easier to modify an existing simulation tool to support the needs of a new analysis than it is to develop a new tool, then it is possible that such a tool will be adopted more universally for such analysis.