Inspection & Services

NRG’s Inspection & Services (I & S) team performs automated non-destructive testing of primary components in pressurised water, boiling water and research reactors.

For high radiant and contaminated components, custom-made manipulators and inspection technology are developed and assembled.

Our passionate inspection team performs Ultrasonic, Eddy current and Visual inspections of steam generators, coolant pipes and pumps, reactor vessels and pressure containers with corresponding qualifications and reporting. At our testing facility in Arnhem, additional studies and material testing are performed.

Our engineering  team finds an inspection solution for every geometry, simple or complex.
The manipulators are designed and assembled by the I&S team, while the parts are produced by specialised companies. The I&S team takes the dose and ALARA principle into account while designing the manipulator.

Our software can control 4 motors, although manipulators with 8 motors are no problem.
All manipulators are tested at 1:1 models of the components. We also test the positioning, probe coupling and possibility to replace components. Besides testing on models, the team will also be trained on the models.

Eddy Current
Eddy Current inspection (ET) is mainly used to analyse surface and welds of components on the impact of radiation. A multi-channel Eddy Current device gives, together with the software and motor encoders, a clear image of the surface or weld. The Eddy Current technique can be easily combined with ultrasonic inspections.

Ultrasonic testing is used to detect irregularities in base material as well as in welds. It can also be used for wall thickness measurement. Ultrasonic signals are translated into a user-friendly interface with our own designed software. Besides detecting irregularities, defect sizing can also be done. In addition to 0°, angled, Single element and Transmit-Receive probes, it is also possible to use Phased Array, ToFD and Tandem techniques, depending on the detection target, material and weld type.

Visual inspection
The I & S team focuses primarily on the visual examination (VT) of used fuel rods and control rod assemblies in boiling water (BWR) and pressurised water reactors (PWR). The integrity of fuel and control rods are inspected using visual inspection cameras and the linearity of complete assemblies can also be examined. Reactor vessels and piping are also included in the visual inspection technique. An endoscope is used to inspect places which are difficult to reach for standard VT cameras. All visual inspections are carried out according to DIN 25,435-4.


Besides designing inspection manipulators, the I & S team also designs special tools and inspections for special assignments. These include grabbing tools to collect radioactive waste from any form of kegs or clamps to pull damaged waste drums up from an underground storage, a brushing machine for removing oxide from fuel elements before EDM machining is used or an arm to make a 3D print of gaskets and filters with Replica Molding technique. Our test facility also provides the ability to test long distance / height tools, even under water testing. 

The inspectors are ISO9712 level 2 or level 3 certified. The Inspection & Services (I&S) team has an ISO / IEC 17025:2005 accreditation from the Dutch accreditation council (Raad van Accreditatie) L576. Qualification is awarded according to ENIQ, ASME, ENSI and KTA guidelines. Where necessary, inspections are qualified and supervised by the local authorities as SQC, SVTI, TÜV and Lloyd's.