Refinement of transient criteria and safety analysis for a high-temperature reactor cooled by supercritical water

In past designs of supercritical water-cooled reactors, the core flow rate has had to be kept high enough to satisfy the minimum deterioration heat fl ux ratio criterion where the deterioration heat flux is a junction of the c ore flow rate. Refinement of transient criteria related to the fuel rod des ign is undertaken, and new dominant transient criteria are proposed in whic h the cladding temperature is < 610 degreesC for Type 316 stainless steel a nd < 840 degreesC,for Inconel 700 to reduce the balance of the plant and im prove the thermal efficiency. The safety analysis for the high-temperature core using these new criteria is carried out. All the analyzed events satis fy, the new criteria. A new formula for the heat transfer correlation at su percritical pressure is proposed based on numerical simulation.