Development on the shaft-seal element for 'Monju' fuel handling machine (phase-1)

In the fuel handling facility for the prototype FBR ''Monju'', the fuel handling machine is the most important. It penetrates through the shielding plug of the reactor into the interior of the reactor vessel. Within the vessel, the machine transfers a reactor core element between the core and an in-reactor relay station. As indicated, owing to the penetration of the reactor shielding plug, in order to form the boundary with primary cover gas, the sealing mechanism plays an important role in reactor safety. Of the sealing mechanism, the shaft seal element for the fuel exchange machine itself required the development of a new type totally different from the conventional concept, because of the severe temperature condition and of the sliding performance. The tests performed in the atmosphere in the course of the development of this shaft seal element are described. (J.P.N.)