2a. Efficient Monte Carlo Simulations in the Cloud

C53-02a-271164Research and development advances in novel nuclear reactor design for power production depend on computer simulations to validate efficiency and safety. Most existing simulation co des require training and expertise and have restrictive licenses that make them hard to acquire and use. One promising open-source code is easy to use and can spread its calculations across many computers, but it lacks the biasing methods essential for rapid evaluation of radiation transport. An existing simulation code will be modified so that—using a minimal amount of computer power—it can precisely evaluate how much radiation travels through matter. A graphical interface will make the code easier to use and will provide a way for researchers to execute their simulations using cloud computing resources, with simulation results presented in the same interface. A weight window method was implemented to bias neutron transport so that the flux can be evaluated globally within a model, even far away from the neutron source. This is implemented with a few simple rules that, for example, drop the neutrons most likely to get stopped within shielding. A prototype browser-based interface was also created that generates interactive visualizations of the initial model and also plots simulation results. The prototype interface will be extended, based on expert feedback, so that it is ready for use in industrial R&D. We will also implement a state-of-the-art biasing method that uses an analytic approach, which will be more efficient for simulating complex systems. Finally, we will generalize the way users can define their model geometries, including allowing them to use existing digital engineering models, instead of translating their models into a specific syntax. A fully-featured, browser-based interface for radiation transport simulations—including new biasing methods—will speed up the R&D phase for fusion reactor design and the validation of small modular fission reactors. Businesses will subscribe to our software to save time and money when evaluating the radiation-related impacts of frequent design changes.