This proposal focuses on streamlining the fusion neutronics calculation workflow to improve integration into the engineering design cycle, which will help advance the development of new fusion technologies. Fusion neutronics involves the computational prediction of neutron and secondary gamma flux fields in fusion devices. These calculations are frequently a dominant engineering bottleneck in evaluating fusion device design iterations, and impact design constraints in areas such as radiological protection, thermal management, material reliability, and maintenance operations. While Monte Carlo methods are the gold standard for fusion neutronics, analysis processes are still largely based on geometry paradigms developed decades ago, and prior to the advent of modern Computer Aided Design (CAD) and Computer Aided Engineering (CAE) practices. The two most significant neutronics calculation bottlenecks include CAD integration and calculation workflow. Days or weeks of user time is often required to simplify parts, and to clean CAD assemblies to remove small, otherwise inconsequential, part interferences. Additionally, neutronics users must often couple together multiple independent calculation tools, leading to a complicated and error prone calculation process requiring high levels of user expertise. This proposal seeks to develop an enabling product to significantly improve engineering productivity by simplifying CAD integration and providing users with a single, unified neutronics calculation process. This product will leverage the use of unstructured tetrahedral meshes, commonly used in CAE, and will build upon two established neutronics tools: Attila4MC and MCNP®. In Phase I, an automated, CAD interference tolerant, mesh generation process for MCNP simulations will be developed. This process will be validated using a realistic tokamak assembly. Additionally, MCNP capabilities will be expanded to support activation on arbitrary tetrahedral elements, forming the basis of a unified analysis process where a single computational mesh is employed for all aspects of neutronics calculations. If successful, the proposed research will result in an enabling product that can dramatically simplify and shorten the neutronics analysis cycle, which in turn can help accelerate the design and development of novel fusion technologies. The proposed team involves a collaboration between industry (Silver Fir Software) and academia (Massachusetts Institute of Technology).
