SS1. Uncertainty Analysis and Reduced Order Modeling

Recent advances in modeling and simulation has emphasized the role of uncertainty analysis as an important tool to assess the credibility of nuclear reactor simulations to support a wide range of engineering decisions like, establishing the satisfaction of safety margins, defining experimental needs for a specific design, mapping validation domains, etc.. To achieve these goals, uncertainty analysis must be able to quantify and prioritize all sources of uncertainties resulting from modeling assumptions, numerical approximations, and model physics and technological parameters. Reduced order modeling has been recognized as a key enabling tool for uncertainty analysis for realistic/complex reactor problems. This session/track solicits papers to advance the state-of-the-art of uncertainty analysis as enabled by ROM techniques. The session is looking for new methods/algorithms that employ dimensionality reduction techniques to shrink the uncertainty space, and quantify errors resulting from reduction, methods employing machine learning and data mining techniques to render reduction and construct surrogate models, Hybrid methods that combine both statistical and deterministic techniques to minimize the computational cost, methods that efficiently sample the uncertainty space for extreme-quantile estimation, efficient techniques for surrogate model construction, and application of these methods to nuclear engineering problems.

SS2. Space Nuclear Systems

The exploration and settling of extraterrestrial space requires nuclear technology for propulsion and power. As interest in the field from both the private and public sectors continues to grow, acknowledgment of nuclear technology's role is likewise increasing. The time for space nuclear is now, calling for research and innovation across nuclear engineering to meet the growing needs of the technology. For successful programs, new methods and approaches must be developed to ensure success. This session covers design methods and designs for fission and fusion based propulsion and power systems as well as radio-isotope generators.

SS3. Validation of Reactor Kinetics Measurements

The reactivity of commercial light water reactors (LWRs) is given by the reactimeter, which computes the core reactivity from a flux variation measurement. For experimental reactors, reactivity worth are measured by the "doubling time" technique. In both cases, the reactivities are computed from the kinetics equations based on delayed neutron (DN) data (αi, λi, νd). The uncertainty on the reactivity, obtained by propagation of the current uncertainty of the DN data, amounts to ±6% (1σ), which is far from LWR design target-accuracy. This Special Session is devoted to the validation of reactor kinetics either by fundamental experiments on DN data (Keeping-type measurements, βeff and αi by core noise measurements) or by direct validation using integral experiments of the relationship between the measured flux variation and the true core reactivity.

SS4. Hybrid Monte Carlo and Deterministic Methods

This special session seeks papers on novel hybrid (Monte Carlo/deterministic) methods. This may include the use of deterministic transport/diffusion theory algorithms and response matrix methodologies (e.g., incident flux expansion method, fission matrix method) for both fixed-source and eigenvalue problems. Additionally, papers focused on the application and benchmarking of the aforementioned methodologies and related algorithms are encouraged. In addition to invited papers, contributed papers are encouraged.

SS5. Fast Reactors

Advances in the development, prototype and testing of current fast reactor designs along with methodologies of analysis, their application and development of related algorithms are encouraged.