We performed a UAS inspection of a low pressure feedwater heater systems’s expansion joint bellows, which are located within a nuclear site’s condenser unit. By using a drone, we completed the inspection in less than two hours, all while the site was performing other work during its refueling outage.
Our mission was to look at all bellows, dogbone shielding, and expansion joints to identify steam shields on extraction steam lines and identify risks related to those defects.
Traditionally, this inspection requires individuals strapped into fall restraint harnesses to be inside the condenser area while scaffolding is being built. The scaffolding alone takes 4-6 shifts to erect and then another 4-6 shifts to demobilize. On top of those 8-12 shifts, an engineer adds an additional shift to review the inspected components. Though contamination of personnel would be low risk, heat stress and fatigue are higher risk in this type of inspection with 90-95° F conditions.
With the significant decrease in inspection time, the team was able to complete all necessary in-processing, obtain all required safety briefs, then collect, process, and deliver data within one work shift. The processed data will be utilized when planning future maintenance. The insights we collected and reported to the site could not have been completed as quickly or thoroughly with a traditional inspection.