The reliability of in-service monitoring of the piping in the reactor coolant system and of certain components within this system subject to severe temperature and pressure conditions is a particularly sensitive issue for nuclear safety. In January 2014, IRSN and the research division of the Nuclear Regulatory Commission (NRC) signed a cooperative agreement on this subject in order to pool their respective know-how and thus further enhance nuclear safety.
The purpose of the four-year Franco-American cooperative agreement between IRSN and the NRC is to pool the advances each organization has made in the area of nondestructive testing of reactor coolant system piping and welded components connected to them, to be able to monitor their condition without having to dismantle them. The effectiveness of the ultrasound tests used currently is limited by the type of materials used to make the piping and components: the coarse-grained materials disrupt ultrasound propagation, making it difficult to characterize defects, especially in the case of parts with complex geometry.
One of the objectives of the IRSN-NRC agreement is to help improve testing techniques and develop new techniques by consolidating the results of research carried out by both partners. Working with the French Atomic Energy and Alternative Energies Commission (CEA), the Institute has already designed a system capable of adapting the ultrasound signal to the different shapes of the parts to be examined. For its part, the NRC has worked on improving signal processing applied to high particle-size materials.