Proposal for ultrasonic technique for evaluation elastic constants in UO2 pellets

• Autor(a) principal: Lopes,Alessandra Susanne Viana Ragone
• Data de Publicação: 2022
• Outros Autores: Baroni,Douglas Brandão, Bittencourt,Marcelo Siqueira Queiroz, Souza,Mauro Carlos Lopes
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Matéria (Rio de Janeiro. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762022000300237
• topic: Ultrasound; Ultrasonic Wave; Elastic Constants; Alumina

ABSTRACT Uranium dioxide pellets (UO2) used as fuel in nuclear power reactors are subjected to high thermal gradients and may undergo swelling during reactor operation. The swelling of UO2 pellets, resulting from the fission products, causes cracking of the material and it is thus critical to study their behaviour. This study evaluated the application of the ultrasonic method in obtaining the elastic constants of UO2 pellets. Due to the difficulties in handling nuclear material, we used tablets of alumina (Al2O3) for a comparative study. For this, two sets of 10 Al2O3pellets with densities of 92% and 96% were fabricated. Ultrasonic transmission technique was used for obtaining measurements of the travel time of longitudinal and transverse ultrasonic waves. Equations relating material density and velocity of the ultrasonic wave to the elasticity, shear and Poisson’s modules allowed the determination of these elastic constants, whose values showed excellent agreement with those available in the literature for Al2O3.