SNAKES manipulator and ARD sluicer testing -- April 1997

Long reach arms represent one of the options available for deployment of end effectors which can be used in the retrieval of radioactive waste, from the Hanford single shell tanks. The versatility of an arm based deployment system is such that it has the potential to improve the performance of a wide range of end effectors compared with stand-alone or other deployment methods. The long term reliability and availability of the deployment system is central to the timely completion of a waste retrieval program. However, concerns have been expressed over the dynamic performance of long reach arms and it is essential that an arm based system can cope with operational dynamic loads generated by end effectors. The test program conducted set out to measure static and dynamic loads and responses from a representative arm and sluicer, with the objective of extrapolating the data to a long reach arm system, that can be used for in-tank waste retrieval. As an arm with an appropriate reach was not available, the test program was undertaken to measure dynamic characteristics of a Magnox Electric 18 ft multi-link, hydraulically actuated SNAKES manipulator. This is the longest reach unit in service, albeit only one third of the 50 ft length required for in-tank waste retrieval. In addition operational performance and loading measurements were obtained from a low pressure confined system sluicer under development by ARD Environmental, to add to the end effector data base. When subject to impulse loading, the arm was found to behave in a repeatable manner having fundamental natural frequencies in the vertical and transverse directions of 1 Hz. There were also a large number of higher natural frequencies measured up to 100 Hz