
The flange portion of an equatorial port plug. Along the rim are holes where the port plug will be bolted--or unbolted in case repair or refurbishment is needed. ''Remote handling equipment will bring the port plug to the machine and plug it in like a cork in a bottle,'' says Victor Udintsev, who leads the Diagnostic Engineering Section.
To an outside observer, port plug structures look like hollow boxes about the size of a bus. But when fully equipped, those boxes will hold diagnostics, integrated services, and other hardware. While the port plug structures are made with ITER-grade austenitic stainless steel to withstand neutrons fluxes and other hazards, the equipment inside will be shielded with steel and boron carbide to provide an extra layer of protection.

This tunnel structure belongs to an equatorial port plug, which is smaller and more elongated than an upper port plug. A total of 23 diagnostic ports will have port plug structures equipped with diagnostics, integrated services, and other hardware. The first two have been completed at CNIM France.