Numerical Simulation Study on Cladding Blister of Parallel Fuel Plates Under Subcooled Boiling

Abstract Plate fuel elements have the characteristic of more efficient heat transfer and are a potential new type of fuel assembly. As the fuel consumption of the reactor deepens, fission gas continues to accumulate and may enter between the cladding and fuel meat, causing cladding blister. In the case of subcooled boiling flow of coolant, the thermal-hydraulic characteristics of plate fuel elements after cladding blister have received little attention. However, cladding blister is a problem that must be faced in the design and development of fuel assemblies. This paper investigated the thermal-hydraulic characteristics of plate fuel elements after cladding blisters using numerical simulation methods. The research results showed that the cladding blister significantly impacts the wall temperature and void fraction distribution of the blister cladding, the blister back cladding, and the blister opposite cladding. The fuel meat temperature under the blister coverage area significantly increased. Further research revealed the effects of blister area, height, and number on plate fuel elements.