PNNL

Abstract

The Gamma-Rover (GRover) is an electrically powered crawler designed to visually inspect and characterize the radiological conditions within the B-Cell and D-Cell ventilation ducting in support of the Hanford Site’s 324 Building Stabilization/Deactivation Project. Due to the bid opening of the Department of Energy’s River Corridor Project prior to deployment, GRover has not yet been deployed. The delay in deployment has allowed the designers to develop lessons learned from the original development in order to propose improvements when the system is deployed in the future. Gamma field information is detected with a pair of Eberline DA1-8/RMS systems. One system is mounted directly on the crawler, while the second is mounted on the deployment platform. Four web cameras on a pair of CAT-5e/USB channels provide video feedback from both the crawler and the deployment platform. The drive system was designed to overcome a potentially difficult path of the duct, which included three ninety-degree bends. Mockups of the duct bends yielded high friction on the tether, and a drive system to overcome this friction was especially difficult to design into such a small package. Deployment was to be performed during a routine air filter change-out. As such, a specialized deployment platform was designed to pass through the existing filter housing. GRover would be required to be staged within the hot cell prior to the filter change-out and could therefore be dosed in excess of 8 hours. Thus, the platform also had to protect the electronics from radiation damage for an extended period of time.