Some of the next generation of small modular reactors have been designed with helically coiled steam generators integrated into the reactor vessel to enhance natural circulation. According to the developers of TASS/SMR, a one-dimensional thermal hydraulic code written to model the Korean Atomic Energy Research Institute's SMART reactor, the Žukauskas...
The effect of fluid axial thermal conduction on one-dimensional liquid metal natural circulation and its linear stability was performed through non-dimensional analysis, steady-state assessment, and linear perturbation evaluation. The Nyquist criterion and a root search method were employed to find the linear stability boundary of both forward and backward circulations....
All nuclear reactors rely heavily on the use of level sensing instrumentation to detect the behaviour of liquid in vessels. The majority of level sensing instruments are differential pressure sensing meters, which are invasive and could be the failure source in the pressure boundary of the primary coolant system. In...
NuScale Power has designed a small modular reactor using natural circulation cooling dependent systems for both steady-state and transient operations. The NuScale Integral Test System (NIST-1) facility was built to supply test data to NuScale Power to verify and validate computer codes for the NuScale Power Mod- ule (NPM) with...
This study is intended to investigate and propose a systematic method for uncertainty quantification for the computer code validation application. Uncertainty quantification has gained more and more attentions in recent years. U.S. Nuclear Regulatory Commission (NRC) requires the use of realistic best estimate (BE) computer code to follow the rigorous...
The development of nuclear fuel and materials requires is a continuous effort to investigate the acute and prolonged effects of irradiation, thermal-material stress, chemical change, or other conceivable damage mechanics acquired during normal operation or accident scenarios throughout its lifetime. As in-core fuel property measurement techniques advance to support in...
Fission product transport in a Gen. IV Gas-Cooled Fast Reactor Plant utilizing vented fuel has been characterized using analytical and computational methods. The goal was to increase current understanding of fission product transport in helium-cooled GFRs using vented fuel and to provide a toolset for determining issues which may arise...
Vortex shedding is a phenomenon relevant to any industry dealing with fluid flow. The shed vortices often produce oscillatory forces, which have been suspect in the catastrophic failure of airplanes and bridges alike. To prevent further engineering failures a better understanding of the underlying physics is needed. It has been...
The next generation of nuclear safety analysis computer codes will require detailed
modeling of two-phase fluid flow. The most complete and fundamental model used for
these calculations is known as the two-fluid model. It is the most accurate of the two-phase
models since it considers each phase independently and links...
Smoldering combustion in wildland fires is difficult to extinguish, can transition to flaming combustion, and produces a significant amount of pollutants. It is necessary to understand parameters controlling smoldering in order to help predict the smoldering behavior and potentially mitigate these hazards. The wide variety of natural fuels that occur...