Designing for Remote Handling: the case-study of the ITER Plasma Position Reflectometry in-vessel antennas

Abstract

The Plasma Position Reflectometry (PPR) system for the International Thermonuclear Experimental Reactor (ITER) consists of four reflectometers designed to measure the edge density profile at four locations, two of them with antennas installed inside the vacuum vessel in small apertures between blankets. To prevent damage, the antennas need to be removed/(re)installed by remote handling (RH) means before/after the removal/reinstallation of the blanket shield modules just above and below them. The RH operations shall be performed by the Blanket Remote Handling System (BRHS), [1], and require a tool not yet available in the ITER Remote Maintenance System. Herein, we describe a conceptual design of this tool that considers guidance and security to overcome some of the identified RH issues. The RH tool is designed to remove and (re)install the antenna in a single step using the translation and rotation capabilities of the BRHS (or a dual-arm manipulator attached to the BRHS) to bolt/unbolt the antenna to/from the support without extra operations. The RH tool is also designed to minimize the space required to operate between the blanket shield modules. However, the guidance pins of the tool are dimensioned according to the maximum positioning error allowed for the BRHS with a diagonal shape to guide the tool along the antenna. The design is implemented using pop-up fasteners and standard sizes authorised by the ITER Organization. A set of mechanical benchmarks are presented based on the CAD model of the tool.