Visual inspections in nuclear environments using a multi-function underwater submarine ROV

Jocham, Marcus; DEKRA; Germany

Marcus, J.; Visatec- a DEKRA company; Germany
Thomas, C.; Visatec- a DEKRA company; Germany

ID: ECNDT-0288-2018

The nuclear industry worldwide needs efficient and innovative ways to carry out non-destructive testing in underwater situations. In particular, nuclear power plants expect a variety of complex underwater inspection activities to be performed during an outage. ROVs such as the Visatec Dolphin, need to inspect both primary and secondary side components as well as RPV internals. Specialist ROV technology allows inspections to happen in situations that are hard to reach with any other inspection method. The newest generation of ROVs can perform sophisticated visual inspections and can incorporate a gripping device that can retrieve fallen debris. Inspections can be carried out for reactor coolant system components, pressure vessels, tanks and piping in nuclear power plants worldwide. The vehicles can be calibrated under water at any time during the inspection process to avoid any interruption to the testing work. These ROVs carry out visual testing (with ultrasonic testing as an option) and can evaluate the status of nuclear reactor internals. In short, this equipment is critical in confirming the safety of components for a nuclear plant’s long-term operation and safety. This paper cites numerous case studies of how our multi-function underwater submarine ROV, the Visatec Dolphin with an integrated gripper arm, has carried out complex inspections in a nuclear application. It also discusses specific problems involved in nuclear reactor underwater testing and presents solutions using the latest ROV underwater technology.