The first two diagnostic port plug structures will be sent to ITER Domestic Agencies to be equipped with diagnostics and other hardware. 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. Two standard types of port plugs are planned—large square models for the upper ports, and smaller, elongated versions for the equatorial ports. A total of 23 diagnostic ports will require port plug structures. The final design was completed in 2015. Then, in October 2016, the ITER Organization awarded a manufacturing contract to CNIM, a company in Toulon, France, just a ninety-minute drive from the ITER site. The team at CNIM is now nearing the final stages of manufacturing for the first two equatorial port plug structures, which will be delivered to the Russian and Chinese Domestic Agencies. The agencies, in turn, will begin loading them with the equipment they are designed to hold. "It's important to manufacture these big boxes now because they are the very first step in the integration of the entire port," says Victor Udintsev, who leads the Diagnostic Engineering Section. "We cannot assemble anything that goes into the machine without these boxes." "There has been a strong collaboration between the ITER Organization and the Domestic Agencies on the structures. Everybody was involved in the design reviews and the planning of port integration; now ITER is doing the port integration, with close involvement from the Domestic Agencies. They are the customers—and ITER acts as the manufacturer, contracting the work out to CNIM." While each of the port plug structures adheres to one of two standard designs, small adjustments will be made depending on the diagnostics encased in each port. "Some diagnostics look to the left of the machine, some to the right," says Victor. "Some sense light in the microwave range; some use light in the visual range." Differences such as these require customizations—including, for example, additional windows and adjustments to the diameters and locations of the holes in the back wall where components are attached. 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. Building strong structures with tight tolerances The most technologically advanced electron beam welding is used during manufacturing to ensure a high-quality and low distortion weld that respects very tight tolerances. The port plug structures must be very straight and when inserted in the machine, the ensuing gap around the structure must be just the right size—large enough to allow the port plug to be pulled back out, but small enough to minimize the passage of neutrons. Basic tests will be run before the port plug structures are sent out for integration—for example, a pressure test and a helium leak test will ensure the cooling circuits have no leaks or cracks­, and that they are unlikely to develop cracks in the future. Then after the components are integrated inside the structures and sent back to ITER, final tests will be carried out at the Port Integration Facility on site. It would be relatively easy to insert an empty port plug structure in the vacuum vessel. The structures themselves weigh up to 10 tonnes, plus or minus a few hundred kilograms, depending on the number of cutouts. But it is a different story when the port plug is assembled, bringing the weight of the entire structure to about 48 tonnes for the equatorial ports and 25 tonnes for the upper ports. A fully integrated port has a different centre of gravity and could suffer from deadweight distortion if the port plug structure is not built to be strong enough. The port plug structures include a flange, which connects to the flange of the vacuum vessel itself. "Remote handling equipment will bring the port plug to the machine and plug it in like a cork in a bottle," says Udintsev. "You put it inside, bolt it on the perimeter with the sealing gasket in-between and then you are done." For repairs, remote handling will be used to unbolt the flange and put the giant box into a cask to bring it to the Hot Cell Facility where the port can be refurbished. CNIM is using a staged approach to manufacturing port plug structures, beginning with the first two that will be sent to ITER China and ITER Russia. Over the next few years, the other 21 port plug structures will be procured and delivered to Domestic Agencies—or to ITER itself—to be completely assembled as integrated ports. ITER is responsible for integration of three equatorial and three upper diagnostic port plugs. Delivery of the first two port plugs marks the beginning of a new phase.  

Ensuring that the ITER Organization, its partners and contractors implement the highest standards of safety and quality is central to ITER. It is a matter of regulation, but it is also a matter of culture. As nuclear operator, the ITER Organization has an obligation to verify that the rules and provisions for Installations nucléaires de base, as defined by French law, are understood and applied by all. Over the past years, ITER nuclear inspectors have performed many such verifications. For a whole week in early June, they were in Korea—first for an in-depth inspection at Hyundai Heavy Industries, the manufacturer of four of the ITER vacuum vessel sectors, then for a one-day audit at one of the companies bidding for the repair and/or re-fabrication of the thermal shield. Although they are ITER Organization employees, nuclear inspectors Thomas Sobrier and Usama Abdulkader are "independent" experts. It is their mission to verify that the ITER Organization itself, the ITER Domestic Agencies, and all the entities that participate in the project implement the requirements related to management of Protection Important Components¹ (PIC) and Protection Important Activities. In Korea, they were accompanied by Gilles Perrier, the Head of ITER's Safety & Quality Department. "Beyond the regulatory inspection process, and beyond the regular contacts we have on the occasion of the ITER Council or other formal meetings, it was very important for me to connect with the teams in the Korean Domestic Agency and build a true, human relationship with them," says Perrier. "And the same goes for the teams at Hyundai Heavy Industries. The personal relationship is essential to keep progressing together in an integrated manner and to align our approach to quality and safety." At the Korean Domestic Agency and at Hyundai Heavy Industries, the inspection focused on how the lessons learned from the manufacturing of the first three vacuum vessel sectors, already delivered to ITER, informed the ongoing processes for the fourth sector and vacuum vessel ports still under fabrication. The inspectors highlighted good practices and identified opportunities for improvement. The visit was also an opportunity to visit the KSTAR tokamak in Daejeon. As for the quality audit at one of the thermal shield repair/re-fabrication bidders, it aimed to verify the company's quality management compliance with the ISO:9001 standard as well as to determine its suitability and capability to meet ITER requirements. Good practices were observed, and opportunities for improvement were identified. ¹French nuclear safety authorities (ASN) classify as Protection Important Components the equipment that keeps the facility in a safe state and prevents or mitigates nuclear risks to humans and the environment. Protection Important Components are subject to regulation and inspection.

Standing against the backdrop of the SPIDER vacuum vessel at Consorzio RFX, in Padua, Italy, is Nao The Robot. He was brought there by students from the local secondary school Liceo Scientifico Fermi who are participating in Italy's national @NAO Challenge, an educational competition that aims to deepen students' knowledge of robotics and disseminate the social potential of service robotics. Aged 14 to 17 the Fermi students decided to program their robot to act as a guide at Consorzio RFX—an Italian research laboratory that has been investigating plasma physics and controlled nuclear fusion since 1996 and is host to the ITER Neutral Beam Test Facility. Although the students had some familiarity with fusion, they required more detailed information on the test facility where ITER neutral beam injection, an auxiliary heating system, will be tested before ITER operation. Following their visit and conversations with researchers, they finalized their narrative and transferred it to Nao, who can now answer almost any question on fusion-related scientific issues and the work performed at Consorzio RFX. Information courtesy of Maria Teresa Orlando, of Consorzio RFX, and Federico Rizzotto, of Università di Padova.