Preliminary Safety Assessment of Liquid Deuterium Premoderator Container for Ultra-Cold Neutron Source at WWR-K Reactor (AlSUN)

This paper presents a preliminary safety assessment of the liquid deuterium premoderator container developed for the AlSUN ultra-cold neutron source, integrated into the thermal column of the WWR-K reactor. Analytical calculations, implemented using Python-based iterative schemes, were conducted to evaluate the container’s response under three categories of hypothetical accident scenarios: (1) power control and cooling failures, (2) breaches in the vacuum insulation, and (3) combustion-related incidents - liquid deuterium deflagration and detonation. Key thermodynamic parameters—including temperature and pressure evolution—were tracked in each scenario to characterize the transient system behavior. The resulting profiles were then used to estimate mechanical stresses on the container walls, considering the thermomechanical properties of the materials used in its construction. Special attention was given to the structural integrity of Aluminum Alloy 5056, assessing its performance under extreme thermal and mechanical loads. These findings lay a foundation for material selection and design optimizations, serving as a basis for future, more comprehensive studies employing advanced simulation tools.