A novel porous sleeve design for Atmospheric Release Valves: Enhancing structural reliability through coupled thermo-fluid-structural analysis

The Atmospheric Release Valve (ARV) serves as a critical safety component in nuclear power plants, responsible for plant cooling and secondary circuit overpressure protection. However, the high-temperature, high-velocity steam flow during operation induces significant erosion and structural deformation in the valve sleeve and plug. To address this, the present study proposes a novel porous sleeve (PARV) design and develops a comprehensive thermo-fluid-structural coupled model to evaluate its performance against the conventional window-type sleeve (WARV). Numerical simulations under typical operating conditions reveal that the PARV effectively reduces the maximum steam velocity by 11.9 % at 50 % opening, thereby suppressing vortex-induced vibrations and erosion potential. Structural analysis further demonstrates that the PARV achieves an 18.5 % reduction in maximum equivalent stress under steady-state conditions and a 28.8 % decrease in peak thermal stress during the heating phase. These results conclusively validate the superior structural reliability and enhanced thermal response of the porous sleeve, providing valuable insights for failure risk mitigation and performance optimization of ARVs in nuclear applications.