This video, “Robotic Inspectors,” highlights new inspection devices developed at the Vermont Yankee nuclear energy station to closely analyze the facility’s steam dryer. Entergy Nuclear employees at Vermont Yankee are recipients of the Maintenance Process Award for developing innovative tooling for the inspection of a boiling water reactor steam dryer. The steam dryer is located in the top of the reactor.
Entergy Nuclear partnered with AREVA NP Inc. to develop two remotely operated inspection systems, one to inspect the outer diameter of the dryer and the other to inspect the inner diameter. The outer diameter innovation uses a rail-and-trolley system with a telescoping mast and camera to inspect all 213 welds and components. The inner diameter method uses an underwater crawler with a telescoping mast and camera to inspect all 253 welds and components.
Advantages common to both inspection systems include: improved safety, higher inspection quality, greatly reduced radiation exposure and parallel inspection capability. An annual reduction of 3.6 person-rem of radiation exposure is expected along with a minimum $500,000 cost reduction per outage. The tooling is highly transferable. It was developed so it can be used on all makes and sizes of dryers, regardless of the rail configuration on the refuel floor. The new dryer inspection tools can be used for dryer inspections at all boiling water reactors.