ºÚÁÏÉçapp

The Cryostat Workshop, in the northeast corner of the ºÚÁÏÉçapp worksite, has become a crowded and busy place. There are now two 30-metre assembly platforms supporting assembly and welding work on the cryostat base and the cryostat lower cylinder. At one end of the 110-metre long building, workers are busy finalizing the welds underneath the first tier of the cryostat base—a perfectly circular plate that is 30 metres in diameter. At the other, workers are positioning the first elements of cryostat lower cylinder on a specially constructed assembly platform that will support the five-metre-tall elements as they are aligned and welded. The space between the two work areas is almost fully occupied by large steel elements, as yet unwrapped and waiting to be assembled. Whereas the massive presence of the base section conveys the exceptional size of the ºÚÁÏÉçapp cryostat (30 metres high and 30 metres in diameter once completed), the early stages of lower cylinder assembly reveal its complexity. The three segments of the lower cylinder that are already positioned on the assembly frame help us to visualize what the completed cryostat will look like: a huge cylindrical steel vessel pierced with dozens of openings. Some are perfectly circular, some are the size of an average window with rounded angles, and a few are as high and wide as a cathedral door. Workers from MAN Diesel and Turbo, the Larsen & Toubro Ltd. subcontractor responsible for assembly and welding, carefully manoeuvre one of the six 60-tonne lower cylinder segments into position on the assembly frame. The second-tier segments will come later, creating a 10-metre-tall component. And we're only seeing half of the lower cylinder. Six tier-two segments, also five metres tall, are expected to arrive at ºÚÁÏÉçapp in late July from their manufacturing location in India. Once completely assembled, the full lower cylinder section will measure 10.4 metres in height and weigh 375 tonnes.In the weeks and months to come, work will progress in parallel on the two lower sections of the cryostat.The bottom plates of the cryostat base (tier one) should be fully welded by the end of this month. At that point, the six curved rim elements of tier two will be installed to be welded to tier one.On the other side of the shop, the three remaining tier-one segments of the lower cylinder will join the three already on the assembly platform to form a full ring.Before our eyes in the Cryostat Workshop, one of the most spectacular and strategic components of the ºÚÁÏÉçapp machine is taking shape. Once completed, it will be the second largest and by far the most complex vacuum-tight container ever built.

In ºÚÁÏÉçapp, beryllium will be used as armour for the plasma-facing first wall panels fitted inside the tokamak. This metal has been chosen in major part for its good thermal properties—that can accommodate the high heat fluxes on the first wall (up to 5 MW/m2)—and its low atomic number that, in case of plasma contamination, minimizes radiation heat loss that could otherwise lead to unacceptable cooling of the hot fusion plasma. Planning is underway now at the ºÚÁÏÉçapp to put in place the management program that will provide for the safe handling of beryllium and a healthy work environment.   ºÚÁÏÉçapp will operate with beryllium-bearing components and in particular, the plasma-facing first wall of the blanket, which will require about 12 tonnes of beryllium to cover a surface of approximately 610 m².   The beryllium used in the manufacture of ºÚÁÏÉçapp components will be non-radioactive; however, measures, systems and actions shall be implemented to control and prevent any beryllium exposure to workers, operators and the public. Classified as a potential carcinogenic, the primary risk with beryllium is the inhalation of beryllium dust.   The ºÚÁÏÉçapp is committed to providing a healthy and safe worksite and work environment through a detailed beryllium safety program. The ºÚÁÏÉçapp Beryllium Management Committee (IBMC) was established in 2015 to ensure the ongoing effectiveness of the program in delivering the working environment demanded by all stakeholders and in compliance with the ºÚÁÏÉçapp Agreement*.   The IBMC is chaired by Blanket Section Leader Rene Raffray supported by Russell Eaton (Blanket Officer) as Technical Secretary, and includes the participation of Legal Affairs, the Committee for Health & Safety, Human Resources, Responsible Officers for components containing beryllium, beryllium-procuring Domestic Agencies, the Occupational Doctor, and ºÚÁÏÉçapp business units for assembly, operations, and radiological and environmental monitoring.   Beryllium, used in the plasma-facing first wall of the ºÚÁÏÉçapp blanket, must be managed through a detailed beryllium safety program. From 28 to 30 June, representatives of beryllium suppliers, manufacturers and users shared their experience with the ºÚÁÏÉçapp and the Domestic Agencies responsible for components containing beryllium. The focus of the IBMC in 2017 has been to set up the ºÚÁÏÉçapp beryllium worker identification process and training program, to identify and produce the needed beryllium documentation and—with the support of the ºÚÁÏÉçapp Director-General—to organize a workshop on beryllium applications and health and safety.   The workshop, held on 28-30 June at ºÚÁÏÉçapp Headquarters, attracted 103 participants including nearly half from outside of the Organization, representing the Domestic Agencies, international organizations, beryllium suppliers and manufacturers, and users from China, Europe, Japan, Kazakhstan, Korea, Russia and the US.   The objective of the three-day session was to clearly identify the ºÚÁÏÉçapp internationally as a major user of beryllium products and a major beryllium actor in the coming decades; to share the Organization's plan on dealing with beryllium issues and to receive feedback from international actors in the field; to learn from those who have experience in the areas of beryllium facility design, on-site operation, monitoring and training; and finally to demonstrate transparency on the ºÚÁÏÉçapp approach to beryllium safety.   In his presentation to the opening session, the ºÚÁÏÉçapp Director-General emphasized that protection of the stakeholders is an essential and top priority for the ºÚÁÏÉçapp, before thanking the external participants for sharing their valuable experience and lessons learned in order to help the ºÚÁÏÉçapp establish a robust and effective beryllium management worker protection program.   Information from the workshop will be particularly useful over the next year to help the IBMC improve the ºÚÁÏÉçapp beryllium training program and develop an ºÚÁÏÉçapp beryllium "code of practice."   * Due to the nuclear nature of the activities carried out by the ºÚÁÏÉçapp, the Parties to the ºÚÁÏÉçapp Agreement stipulated that the ºÚÁÏÉçapp shall observe applicable national laws and regulations of the Host State (France) in the fields of public and occupational health and safety, nuclear safety, radiation protection, licensing, nuclear substances, environmental protection and protection from acts of malevolence (Article 14).

Jean-Paul Philippe is a renowned French artist who specializes in abstract, monumental sculptures. One of his most famous works is in Asciano, a village near Sienna, Italy. It features large stone structures reminiscent of the Puerta del Sol of ancient Tiwanaku in Bolivia. Asciano happens to be the "sister city" of La Roque d'Anthéron, a village located some 30 minutes east of the ºÚÁÏÉçapp worksite and one that is skirted by the ºÚÁÏÉçapp Itinerary.   A few years ago, the mayor of La Roque d'Anthéron and Philippe met and decided that the "sister city" deserved a "sister monument."   "My work in Asciano had to do with the Sun," explains the artist. "It was quite a coincidence that the convoys that deliver components to the artificial Sun of ºÚÁÏÉçapp pass right by Asciano's sister city."   In the spring of 2016, Philippe visited the ºÚÁÏÉçapp site and was convinced.   The artist, sitting here next to the Asciano sculpture, sees his work as an "enigmatic signal" for ºÚÁÏÉçapp. What is missing for the moment is the funding ... The monument he designed for ºÚÁÏÉçapp features a high column made of seven granite blocks—the seven ºÚÁÏÉçapp Members—rising from a stone platform. A small-scale model of the sculpture is currently on exhibit at the Musée Granet in Aix-en-Provence.   On the top of the column, a notch is hollowed out and covered with gold foil to "gather the light of the setting Sun." The light at the end of day will also reveal Einstein's "ΔE=Δmc2" mass-to-energy conversion formula that is at the core of the fusion reaction. Halfway down another hollow in the form of a crescent Moon is meant to catch the morning light.   The sculpture aims to be "enigmatic," says the artist—a "signal" on the way to ºÚÁÏÉçapp that the transport convoys will pass on their way to the construction site.   What is missing for the moment is the funding. The artist and the municipality of La Roque d'Anthéron plan to establish a committee to gather contributions from institutions and private companies.

Ten years ago, KSTAR (the Korea Superconducting Tokamak Advanced Research) was entering the last phases of assembly. In this picture, taken on 11 January 2007, the KSTAR staff posed to celebrate the completion of "in-cryostat" system integration, prior to the cryostat assembly. Among the KSTAR staff in the picture, close to a dozen are now working at ºÚÁÏÉçapp: Gyung-Su Lee, now ºÚÁÏÉçapp Deputy-Director General and Chief Operating Officer; Joo Shik Bak, Head of the Construction Department; Chang Ho Choi, head of the Vessel Section/Division and several others.Eight months after the picture was taken, on 14 September 2007, the construction phase of the project was completed, On 13 June 2008, KSTAR successfully produced its first plasma.

Recent experiments performed on the EAST superconducting tokamak in Hefei, China have demonstrated the sustainment of high temperature plasmas in the so-called H-mode confinement regime over a record timescale of over 100 seconds, as reported by the Institute of Plasma Physics, Chinese Academy of Sciences. On 3 July operators at EAST achieved a stable 101.2 second steady-state high confinement (H-mode) plasma. In its press release Chief Operator Xianzu Gong thanked the collaborators at home and abroad who have contributed over the past decade to upgrading the machine and to solve a series of key technical and physical issues closely related to steady-state operation.H‐mode describes the sudden improvement of plasma confinement in the magnetic field of tokamaks by approximately a factor of two, and is the high confinement regime that all modern tokamaks, including ºÚÁÏÉçapp, rely on. Research at EAST on physics and technology issues under steady-state operational conditions is directly relevant to ºÚÁÏÉçapp. Read the full press release on the IPP-CAS website.

The complexity of the ºÚÁÏÉçapp vacuum vessel, its dimensions, the quantity of welding, and the degree of precision required makes the manufacturing effort for this strategic component one of the most challenging of the entire project. Procurement responsibility falls to Europe and Korea. In 2010, the European Domestic Agency selected the AMW consortium (Ansaldo Nucleare S.p.A, Mangiarotti, Walter Tosto) for its share of the vessel sectors. Today, following detailed engineering, prototyping and qualification phases, manufacturing activities are in full swing.In a recent video filmed at the Walter Tosto premises in Chieti, Italy, we get an insider's access to fabrication activities: the qualified technicians, specialized tooling, and many subcomponents involved in the fabrication of vacuum vessel sectors #5 and #4. (Nine sectors in all will form the full ring of the torus-shaped vacuum vessel.)View the Walter Tosto video.

To predict the impact of removing exhaust heat from the ºÚÁÏÉçapp Tokamak, researchers are calling on the Titan supercomputer at the Oak Ridge Leadership Computing Facility in the US. Using the 27-petaflop behemoth, researchers based at Princeton Plasma Physics Laboratory (PPPL) are simulating the area where the plasma edge meets the divertor—the material structure engineered to remove exhaust heat from the vacuum vessel. Specifically, the team has evaluated the heat-flux width at the divertor, or the width of the material surface that might sustain the highest heat load. Because the divertor directly faces the exhaust flow, it is bombarded with hot particles driven by electromagnetic fluctuations. In ºÚÁÏÉçapp, in order to withstand the highest surface heat load, the divertor will be made of the toughest element on Earth: tungsten. "You don't want to start and stop ºÚÁÏÉçapp too often to replace this divertor material, so it has to be able to withstand the heat load," team leader C.S. Chang reports. "Ideally, we want the hot exhaust particles to hit the surface in a much wider area so that it's not damaged." Based on simulations made possible by Titan's supercomputing capacity, Chang's team predicts that in ºÚÁÏÉçapp, due to the size of the plasma, edge plasma turbulence may spread heat across a larger area of the divertor surface and significantly increase the heat-flux width relative to current smaller-scale fusion devices. Read the full report on research results at OLCF.