Surface measurements and calculation of radial plays between RPV and internals

Grataloup, Mickael; Omexom NDT Engineering and Services; France

Grataloup, M.; Omexom NDT Engineering and Services; France
Ponton, J.; Omexom NDT Engineering and Services; France

ID: ECNDT-1007-2018

The increase in the life time of equipment and the control of its aging are important issues for the competitiveness and safety of nuclear power plants. Aging raises new challenge and requires the monitoring of new areas and the development of new inspection procedures. In this context, EDF decided to have a surface measurement method and calculation of plays between these three major components (lower internals, upper internals and reactor pressure vessel). The solution proposed by OMEXOM NDT Engineering and Services is an automated profiling test by UT PA using 4 robots in order to inspect these interfaces (Reactor clevis inserts and Core Barrel Radial Keys, interface between RPV and Lower internals and UCP pins and UCP inserts, interface between lower and upper internals). Inspection occurs under water in the reactor pressure vessel and the cavity pool with internals on their stand. The development of the solution will return accurate dimensions of the faces using an ultrasonic profiling technique. This information will allow after processing to draw the topography of each surface and to calculate the functional plays. The presentation describes the physical principles used for dimensional measurement and calculation of plays, tooling design and issues related to the operation