Some regions inside a nuclear reactor are not inspected because they are not accessible with current technology. Limited-access Remotely Operated Vehicles (ROVs) such as "FireFly" have been successfully used in limited cases to inspect inaccessible areas of concern in the reactor. However, the reliable performance of these ROVs has been severely limited by their electric motors which have a very short mean time between failure due to flooding (i.e. 72 to 96 hrs.). This project will identify design modifications that allow electric motors to run flooded with reactor-quality water, thus enabling the motor to operate throughout an entire nuclear refueling outage without replacement. In addition, an adjustable orientation control will be incorporated in the new design, increasing accessibility to more areas of the reactor by allowing a vertically-oriented ROV to change to horizontal orientation. Phase I will consist of: (1) an engineering analysis of the ability of electric motor systems to run flooded, and a 100 hour test of a flooded electric motor to identify failure points; (2) a definition of FireFly ROV current orientation parameters, an adjustable orientation design, and a mock-up test of the adjustable orientation ROV concept; and (3) a conceptual design for a limited-access ROV with a new configuration that utilizes the flooded motor concept and adjustable orientation.
Commercial Applications and Other Benefits as described by the awardee: The improved ROV should enhance inspections at nuclear facilities. Benefits should range from improved safety operation of nuclear plants to improved efficiency and shorter refueling/maintenance outage schedules
