Instabilities in two phase and supercritical water natural circulation accident tolerant fuel system

To vanquish the ever increasing demand of energy and trounce the carbon dioxide emission; the human race is looking towards the renewables and nuclear energy as the plausible sources. During the past few years the general public consensus about the later have taken a negative turn; attributed to the Fukushima nuclear disaster. To counter this nuclear unit designers have proposed the idea of Accident Tolerant Fuels (ATF) together with a blend of passive methods of heat removal. To this end an innovative ATF cooled by boiling water in normal conditions and SCW (Super Critical Water) during the accident condition is in the pre-conceptual levels of development at Seoul National University, Korea. Various considerations are to be taken into account while designing the fuel assembly. One of the key challenges which is to be discussed here is the flow instability or flow perturbations, which may pose a considerable challenge to the heat transfer, can induce failure of control mechanism and lead to fatigue damage of reactor components. To counter this precise control of the parameters affecting the system both in normal and accident condition should be done, which may require detailed experimental and numerical investigations within the purview of the proposed system.