A structured-light method for the measurement of deformations in fuel assemblies in the cooling ponds of nuclear power plants

Increasing the functional reliability, the lifetime, and the burn-up height are significant tasks for improving nuclear fuel. To solve these problems, it is necessary to ensure a high level of geometric stability for fuel assemblies during their operation in nuclear-power plants when mechanical deformations such as bending and twisting of the fuel assemblies are caused by various factors. In order to obtain objective information on the postreactor condition of fuel assemblies, analyze the information, and make recommendations for updating their structure, it is necessary to measure their geometric parameters in the cooling pond of a nuclear-power plant where the fuel assemblies are placed after they have operated in the reactor. Considering this problem, the authors developed and studied an optical structured-light method. This paper presents the theoretical calculations of the method and the experimental bench, describes the research, presents the results, and gives recommendations for the application of the method.