Performance analysis of heat pipe-based passive in-core decay heat removal system for the small modular reactor design with MARS-KS code

Abstract

This study explores the effectiveness of using Passive IN-core Cooling Systems (PINCs) for Small Modular Reactors (SMRs) during Station Blackout (SBO) conditions. An introduction to the concept of PINCs, along with strategies for their application to SMRs with design modifications, is presented. Transient safety analysis was conducted using the MARS-KS code on NuScale SMR designs that incorporate PINCs. The findings demonstrate that PINCs can serve as an additional means for decay heat removal in addition to the existing safety systems. The feasibility of PINCs as an effective means for indefinite cooling of SMRs was affirmed under SBO conditions, even in the absence of DHRS and ECCS operations. The PINCs system demonstrates its potential as an effective means for pressure reduction and long-term or indefinite cooling in SMRs under extreme conditions such as SBO.