Work

Computational fluid dynamics investigations of the impact of CANDU fuel bundle rotational misalignment on flow behaviour and fuel temperatures

Year: 2026

Type: article

Abstract: CANDU reactors have fuel channels consisting of 12-13 CANDU fuel bundles, and the rotational angle of each fuel bundle is not controlled when it is loaded into the channel. Coolant behaviour, which may be affected by bundle rotational misalignment, can influence fuel performance; however, the degree of this impact is not yet well understood. This work performed Computational Fluid Dynamics (CFD) simulations with heat transfer using STAR CCM+ on two CANDU 37M fuel bundles with four different rotational misalignment angles (0°, 20°, 40°, and 60°). By comparing the predicted coolant behaviour and fuel temperature profiles, it has been determined that misalignment can alter subchannel mass flow rates by over 40% and increase the maximum fuel temperature by approximately 20 °C. This study also investigates the physical mechanisms by which a misaligned endplate affects these outcomes, through a detailed examination of coolant flow behaviour in the endplate region.

Source: Progress in Nuclear Energy

DOI: 10.1016/j.pnucene.2026.106368

Authors: Zheng Lu, Markus H.A. Piro

Institution: McMaster University

Language: English

Topic: Nuclear Engineering Thermal-Hydraulics

Subfield: Aerospace Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $2,930