Development and validation of a thermal hydraulic transient analysis code for offshore floating nuclear reactor based on RELAP5/SCDAPSIM/ MOD3.4

摘要

Offshore floating nuclear power plants (OFNPs) can effectively solve the offshore energy supply problem in marine resource development and island construction. Affected by ocean waves and other ocean conditions, the OFNPs can generate different kinds of ship motions, which can oscillate the thermal hydraulic parameters and threaten the reactor safety. In the present study, ocean condition theoretical models are established by considering the effects of three basic movement forms (static inclining, linear motion and rotation motion) as well as the coupled ship motions. A thermal hydraulic transient analysis code for OFNPs is developed by adding ocean condition theoretical models into the RELAP5/SCDAPSIM/MOD3.4 code. The experimental data obtained by zero power loading experiment and single-phase natural circulation experiment under rolling motion are used to verify the ocean condition theoretical models as well as the code modification strategy. Results show that the flow fluctuation behaviors caused by rolling motion can be well simulated by the developed code. The calculation capability of modified RELAP5 code under static inclining and heaving motion is also verified by comparing with RETRAN-02/GRAV code. Besides, the effects of the coupled ship motions on natural circulation system are studied by the modified RELAP5 code. Compared with the basic movement forms, the coupled ship motions can cause greater flow fluctuation and obviously reduce the core flow rate, which means the influence of the coupled ship motions is necessary to be considered in the safety analysis of OFNPs. (C) 2018 Elsevier Ltd. All rights reserved.