Silicon carbide composite cladding failure evaluation model under reactor accident condition

Abstract

The invention discloses a silicon carbide composite cladding failure evaluation model under a reactor accident condition, and belongs to the technical field of nuclear industry materials. According to the model, stress distribution caused by internal and external pressure difference, radial temperature gradient and irradiation swelling is obtained by analyzing a heat transfer behavior between a multi-layer silicon carbide composite material cladding and a coolant at a re-submerging stage of a large break accident LOCA and introducing a cladding oxidation factor when the LOCA occurs, and the cladding failure probability under the pseudo-plasticity of the silicon carbide composite material is calculated by using a Weibull fracture theory; according to the method, the change of the heat transfer coefficient is considered, and related variable factors are more comprehensive; and the influence of oxidation reaction between the silicon carbide composite material cladding and the coolant and pseudo-plasticity of the silicon carbide composite material on the failure probability during an accident is also introduced. The method can evaluate the cladding integrity of the nuclear reactor in the accident stage, and ensures the safety of the nuclear reactor. The obtained failure probability data has a higher reference value for security evaluation.

Description

technical field [0001] The invention belongs to the technical field of nuclear industry materials, in particular to a failure evaluation model of silicon carbide composite cladding under reactor accident conditions. Background technique [0002] Accident tolerant fuel (ATF) has become a hot spot in the field of nuclear fuel, and the design and development of accident tolerant fuel cladding is one of the important tasks. Silicon carbide has the characteristics of high melting point, corrosion resistance, good thermal conductivity, and low neutron absorption cross section. Compared with traditional zirconium alloy materials, it has more advantages in high temperature resistance, radiation resistance, and steam oxidation resistance. Silicon composites can improve the fracture toughness of the entire cladding and are therefore candidates for accident-resistant fuel cladding. [0003] Generally, the calculation and testing of the failure probability of the silicon carbide claddi...

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Problems solved by technology

Therefore, the heat transfer coefficient under normal working conditions is usually set as a constant quantity, although this approach simplifies the model but produces a large error to the final result

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