MocDown

Jeffrey Seifried (alumnus)

MocDown (http://jeffseif.github.io/MocDown/) is an efficient tool which loosely couples simulations for neutron transport, isotopic transmutation, thermo-fluids, and the equilibrium core composition search within advanced nuclear reactor cores. The development of MocDown focused on facilitating both fast runtime (by employing concurrent threading and efficient regex parsing when possible) and fast post-processing (with simple and consistent hierarchical storage of result files). MocDown also employs object-oriented programming in Python 3 for flexible modification with external libraries.

To do so, MocDown couples three models for self-consistent simulations: thermo-fluids, neutron transport, and transmutation and recycling. The MocDown accelerated recycling scheme efficiently finds the equilibrium cycle, whose isotopic composition matches that of its successor. Using these techniques, MocDown has been successfully used to simulate the RBWR-Th design, a fuel-self-sustaining nuclear reactor core design which operates with only thorium as its charge.

PyNE

Josh Howland, Marissa Ramirez-Zweiger (alumna), Katy Huff, Rachel Slaybaugh

Tools used in the fields of Data and Computational Science have undergone many rapid modernizations, including a shift to the use of cleaner, more forgiving programming languages and frameworks. Computational neutronics has begun to follow this trend, though this is impeded by the number of legacy codes are written in older, less accessible languages and under antiquated programming modes. Recent work in PyNE aims enable the transition to modern languages and programming paradigms, providing modules in Python that interface with legacy Fortran programs.

The National Nuclear Data Center (NNDC) provides a suite of Evaluated Nuclear Structure Data File (ENSDF) Analysis and Utility programs written in Fortran.  Constantly trying to manage and call 20+ different executables is hard to manage and can rapidly become fragmented. Work is in progress to create a Python interface for the majority of these programs in PyNE.  Python allows for significantly easier access, and modern paradigms in programming including testing and modularity.   

Multi-physics modeling of fluoride-cooled high-temperature reactors (FHRs)

Xin Wang, Dan Shen, Katy Huff, Manuele Aufiero, Massimiliano Fratoni, April Novak

Multi-physics modeling of fluoride-cooled high-temperature reactors (FHRs)To improve understanding of coupled physics in FHRs, this work involves the development of tools and methods for coupling at thermal hydraulics and neutronics within the context of FHRs. Low-dimensional models relying on simplified neutron kinetics and heat transfer have been implemented in a python package, PyRK. Higher dimensional models that couple these physics in finite element frameworks (including both MOOSE and COMSOL) are also being developed. Finally, models which coupled monte carlo simulation with CFD tools are also being iterated upon.