Plant Water Chemistry and Material Degradation

The move toward higher-burnup fuels and the introduction of SMRs are creating new challenges for coolant chemistry, surface deposition, and purification performance in water-cooled systems.​

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In PWRs, higher fuel burnup and power uprates promote the formation of CRUD deposits on fuel rods, leading to issues such as CIPS and CILC. Accurately predicting CRUD formation requires coupling transport phenomena, surface chemistry, and evolving coolant conditions, which become even more complex with changes such as zinc injection, LiOH–KOH transition, and Cr-coated ATF cladding.​

At the same time, SMRs such as Korea’s i-SMR impose strict size constraints on purification systems. The compact chemistry control and coolant purification systems must operate at ~150 bar and 50–70 °C without pressure-relief stages, relying on small ion-exchange units to control coolant chemistry. These conditions raise critical questions about the integrity and adsorption performance of nuclear-grade resins under high-pressure, high-temperature operation.