The jig will ultimately be used to assemble two kilometres of diagnostics cabling through conduits in the torus. The new diagnostics cabling is part of an integrated package of JET enhancements, the aim of which is to develop an understanding of ITER torus materials issues.
The JET ILW project is replacing the existing JET carbon-fibre composite (CFC) tiles with a configuration of plasma facing materials consistent with the ITER torus design. Additional diagnostics are needed to assess erosion and migration of the main beryllium wall material, the behaviour of molten beryllium and its impact on the operation and integrity of the wall, fuel retention in beryllium tiles and interaction of beryllium with background oxygen. The new diagnostics will include thermocouples, visible and IR cameras, and analytical spectroscopic techniques.
Engineers on JET need to install additional wiring to support the new diagnostics, so the conduit being built will carry up to 180 cables. All the cabling has to be installed using remote handling.
Bob Pearson, contracts project manager at JET, said: ‘From past experience we’ve found that when using remote handling it’s best to have a jig that we can use to accurately manufacture the stainless steel conduit with torus anchoring points already integrated within the conduit to ensure problem-free installation of the conduit. The Morson-built jig is intended to do this.’
The 6m jig could be prone to distortion, so Morson is using lasers to check the jig during set-up and manufacture.
Andy Hassall, business development manager a Morson Projects, said: ‘This is our first fusion project. The most demanding part has been the accuracy of the conduit construction. We’ve drawn on our aerospace experience to deploy a laser-based metrology system that sets and checks the accuracy of the jig assembly.’