In general, three different types of processes can be utilized to cut thick stainless-clad steel: waterjet cutting, mechanical cutting, and thermal cutting (plasma, flame, and EDM cutting). Because stainless steel contains a lot of Cr, Ni, and other elements with high ignition and melting temperatures, flame cutting is not recommended for direct cutting of stainless steel. Three different stainless-clad steel specimen thicknesses were prepared for this study, and cutting experiments were conducted utilizing the flame-cutting procedure. The tests demonstrate that using suitable flame-cutting parameters can yield the optimal cutting process parameters and successfully cut thick stainless-clad steel.

Thermal spray coatings commonly have pores and micro cracks in their structure. Corrosive medium will pass through pores and micro cracks in corrosive conditions and damage the substrate, leading to coating failure and reduced service life. In this study, vacuum impregnation sealing (VIS) and conventional impregnation sealing (CIS) were used to seal high-velocity arc-sprayed NiCr-based coatings. The cross-sectional microstructure of the coating and its porosity are observed by optical microscopy. Energy spectrometry and scanning electron microscopy were used to measure the sealant’s penetration depth. corrosion behavior was studied by neutral salt spray testing and electrochemical methods. The results showed that the average depth of sealant penetration by VIS is 275 m, almost three times greater than that of CIS. Better corrosion resistance was indicated in the coating sealed by VIS, which had a smaller corrosion current density and a more noticeable passivation zone than the coating sealed by CIS. The coating sealed by VIS showed no rust stains after 432 hours in the salt spray corrosion environment, but the coating sealed by CIS showed corrosion rust spots after 96 hours. The coating sealed by VIS appeared to have greater corrosion resistance, providing experimental support for its use in engineering.

In the low-pressure injection system (LHSI) of the PWR unit, two branch pipes of the recirculation pipeline are vulnerable to fracture during minimal-flow operation. Flowmaster was used to create a hydraulic model for the LHSI minimal-flow operation and to simulate the branch double-end shear fracture condition in order to predict the leakage flow volume and the water level drop rate of the refueling water storage tank (RWST) in order to analyze the impact of branch pipe fracture on the water leakage of the RWST. According to the study results, there is very little deviation between the operating condition of the system as it actually is and the Flowmaster model, and the leakage volume following branch pipe fracture is considerably less than that of the RWST. Leakage volume per minute is around 0.025% of the RWST’s overall volume, which has negligible influence on the unit’s safety. Based on the results of the simulation, this study suggests LHSI system operation recommendations.

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In this study, we present a method to predict the working volume flow rate of H4 conditions in nuclear power plants. The working flow rate can be predicted using the intersection points of the two curves on a hydraulic characteristic diagram using the quantitative relationship between fluid flow and pipe resistance under the turbulence model and the hydraulic performance characteristics of the hydraulic equipment. The H4 condition volume flow rate of a power plant is predicted in this research using this method. The findings demonstrate that the method can substitute the actual H4 working condition test to lower operating costs while having high accuracy and little deviation. This approach can be usefully expanded to cover more comparable circumstances.