Heat Transfer and Corrosion Dynamics in Pressurized Water Reactors

Pressurized water reactors (PWRs) rely on efficient heat transfer between the fuel cladding and the primary coolant to sustain power generation while maintaining safe operating temperatures. Within the high-temperature, high-pressure environment of the reactor core, corrosion products released from structural materials precipitate onto fuel surfaces, forming porous deposits commonly known as CRUD (Chalk River unidentified deposit). These deposits alter local thermal resistance, impede nucleate boiling and shift axial power distributions—a phenomenon termed chemical and induced power shift (CIPS). Uncontrolled CRUD accumulation can reduce the critical heat flux margin, elevate cladding temperatures and complicate boron control, with direct implications for reactor performance and safety. Recent advances in computational modelling and experimental analysis have deepened understanding of the coupled thermal-hydraulic and corrosion processes that govern CRUD growth, heat transfer deterioration and radionuclide behaviour. The global significance of this research lies in optimising reactor efficiency, minimising corrosion-induced risks and informing maintenance strategies across the existing fleet of PWRs and future designs.

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Heat Transfer and Corrosion Dynamics in Pressurized Water Reactors publication trend

The graph below shows the total number of articles in heat transfer and corrosion dynamics in pressurized water reactors across all publications each year (not limited to Nature Index journals).

Technical terms

Pressurized Water Reactor (PWR): A nuclear reactor design that uses water under high pressure as both coolant and neutron moderator, preventing boiling in the core.

CRUD: Porous corrosion product deposits on fuel cladding, composed of metal oxides and precipitated chemistry that impede heat transfer.

CIPS (Chemical and Induced Power Shift): A shift in the reactor’s axial power distribution caused by asymmetric deposition of boron-rich CRUD on fuel rods.

Nucleate Boiling: A heat transfer regime where vapor bubbles form at discrete sites on a heated surface, enhancing heat removal until critical flux is reached.

Critical Heat Flux (CHF): The threshold heat flux beyond which stable nucleate boiling collapses, risking rapid temperature rise and material damage.

Boron Hideout: The absorption and retention of boron compounds within CRUD layers, affecting coolant chemistry and reactivity control.

References

1. Research of Thermal Hydraulic Conditions Effect on PWR CIPS Risk. Frontiers in Energy Research (2022).
2. Nucleate boiling within a fuel assembly affected by CRUD. EPJ Web of Conferences (2024).
3. A Combined Method for Predicting the Boron Deposited Mass and the CIPS Risk. Science and Technology of Nuclear Installations (2019).