Patent ID: 9360207
Filing Date: 2016-06-07
CPC Classification: F22B,G01N

Claim Text:
1. An assembly for detecting and measuring a rate of fouling, by deposits containing at least one ferromagnetic material, of flow holes in tube support plates of a secondary circuit of a steam generator of a pressurized water nuclear reactor, the generator comprising a bundle of primary water circulation tubes, vertical branches of the tubes being held in the flow holes of the tube support plates, each flow hole having at least three alveoli separated by solid portions in contact with one of the tubes of the bundle, the assembly comprising: a probe which can be moved inside and along one of the tubes of the bundle of primary water circulation tubes, the probe comprising a body of cylindrical elongate shape with a central longitudinal axis, the body carrying on its outer surface at least three magnetic field emitters for emitting a magnetic field, the body of the probe containing at least three magnetic field detectors for detecting the magnetic field, each magnetic field detector being positioned between two angularly consecutive magnetic field emitters, the body carrying on its outer surface at least one magnetized source for angular self-orientation of the body of the probe relative to the solid portions of the flow holes, arranged such that the at least three magnetic field emitters are each automatically angularly positioned opposite one of the solid portions and the at least three magnetic field detectors are each automatically angularly positioned opposite one of the alveoli when the probe inside the tube is moved to each flow hole, an assembly of the magnetic field detectors being connected by a connector to a system for amplifying and displaying signals transmitted by the magnetic field detectors when the probe moving in the tube arrives at each flow hole to be inspected in the tube support plates, the at least one magnetized source being a permanent magnet or an electro-magnet, the magnetized source having a North-South magnetic axis extending radially from the central longitudinal axis of the body of the probe.