SBLOCA analysis of a floating nuclear reactor under ocean conditions using MARS-KS moving reactor model

Abstract

With increasing demands to reduce greenhouse gas emissions from the maritime industry, nuclear power has emerged as a potential solution. Among these options, offshore floating reactors have been demonstrated and developed by various organizations and countries. The offshore floating reactors offer advantages such as a long refueling period for enhanced safety and high mobility, enabling access to remote areas. However, when operating on a moving platform, offshore floating reactors are exposed to external forces that can affect the thermal-hydraulic properties within the reactor core and various hydraulic components. To address the safety concerns associated with offshore floating reactors, evaluating their thermal-hydraulic performance under different ocean motions is necessary. Therefore, this study focused on conducting accident analyses in an offshore floating reactor called BANDI-60, specifically investigating a Small Break Loss of Coolant Accident caused by a double-ended guillotine break in the Direct Vessel Injection line using the system analysis code MARS-KS. Various ocean conditions were considered, including static inclination, combined inclination with heaving, and rolling motion. Among these conditions, static inclination, especially when the break was aligned downward with the inclination direction, was identified as the most significant factor affecting the integrity of the reactor core.