Thermal Hydraulic Analysis of a Novel Passive Residual Heat Removal System with Loop Thermosyphons for the Pool-vessel Reactor

Advanced pool-vessel reactors require reliable, secure, and passive mechanisms to discharge residual heat from the reactor following shutdown. For this reason, this paper proposes a novel Passive Residual Heat Removal System (PRHRS) with loop thermosyphons. To evaluate the residual heat removal and heat transfer capabilities of the PRHRS, a numerical analysis tool is developed. To achieve this, A thermal hydraulic model is established by secondary development of ANSYS FLUENT, designed to couple the primary loop, reactor pool, and loop thermosyphons. A feasibility study is conducted utilizing the proposed model, and the results demonstrate that this system can efficiently and promptly transfer residual heat to the reactor pool and ultimately to the atmosphere, preventing the core from overheating as well as the pool water from saturated boiling. This model is highly effective in analyzing the thermal hydraulic and safety characteristics of pool-vessel reactors and providing technical support for the design and optimization of the PRHRS.