Fields Medal Villani sees where equations lead

There’s poetry in mathematics and this may be the reason why Cedric Villani, one of the most brilliant mathematicians of his generation, dresses as a 19th century romantic poet—long, dark riding coat; large, loose cravat that the French call a lavallière and, of course, shoulder-length hair. (Oftentimes, a large brooch in the form of a spider is also pinned to his lapel.)

A professor at the École normale supérieure and the director of the Institut Henri Poincaré, Villani, 39, was awarded the Fields Medal two years ago. The Fields—equivalent in prestige to a Nobel Prize (not awarded for mathematics)—is the highest prize a mathematician can receive.

Although not directly connected to fusion research, Villani’s work stands „at the extreme theoretical end of ITER,” exploring the properties of some of the equations that describe the behaviour of particles in a plasma, or the movement of stars in a galaxy.

In the summer of 2010, he taught a course at Marseille’s international centre for mathematics meetings (Centre International de Rencontres Mathématiques) as part of a program on mathematical plasma physics related to ITER. Last Thursday 20 December, before giving a seminar on non-linear Landau damping at the CEA Cadarache-based Institute for Magnetic Fusion Research (IRFM), he paid a visit to the ITER site with a party of IRFM physicists.

In a previous Newsline interview the Fields Medal laureate had stressed the importance, when one deals with abstractions, of remaining solidly „anchored in reality.” The mathematical equations he explores, after all, are the true foundations of the ITER project.

Reviewing the progress of drain tank manufacturing

Five large-scale drain tanks are planned for ITER’s Tokamak Cooling Water System (TCWS)—two safety drain tanks; two normal drain tanks; and one drain tank for the neutral beam injection system. These drain tanks are the largest captive components of the TCWS, planned for installment in Tokamak Building level B2 in mid-2014. Fabrication of the drain tanks is underway as part of the US Domestic Agency (US-ITER) commitment to ITER.

Four of the tanks measure 10 m in height and have an internal diameter of 6.25 m (the neutral beam injection drain tank is about half the height, with the same internal diameter). The stainless steel plates used for the fabrication of these tanks are polished prior to manufacturing in order to achieve a minimum surface finish of 1.6 micrometres.

Polishing work on the stainless steel is currently underway in Philadelphia, Pennsylvania (USA) at Stainless Steel Services, a US Domestic Agency and AREVA FS subcontractor. During the second week of December, members of the ITER Organization Cooling Water Section and Quality Assurance Division visited the US-ITER subcontactors and their sub-tier suppliers in order to review the progress of drain tank fabrication work.

The year in pictures

Another year has passed — the fifth since the ITER Organization was officially established on 24 October 2007.

The year 2012 was, first and foremost, „the year of the Decree.” On 10 November, the French government authorized the construction of the Installation nucléaire de base ITER, the first fusion installation in history to qualify as a nuclear installation.

It was also the year during which all ITER personnel was „repatriated” onto the ITER campus: on 16 November the rotogate allowing the passage between the ITER offices inside the CEA-Cadarache enclosure and those on the ITER site was closed.

Work was finalized in 2012 on the Tokamak Complex Seismic Pit—basemat, retaining walls and 493 seismic columns and pads.

Construction activities were launched in two new areas: a 3,500 square-metre Contractors Area, future base for the construction companies and a large number of workers, and the Assembly Building that will host the pre-assembly operations of ITER components.

More and more news has reached us about pre-manufacturing and manufacturing activities being carried out by the ITER Domestic Agencies and their suppliers all over the world.

A definite shift can be felt: the ITER project is moving away from design activities and onto the fabrication of precise, high-tech components.

For the last issue of 2012, the Newsline team offers its readers a selection of twelve of the year’s most evocative photos . We look forward to keeping you closely informed about the ITER project 2013. 
ITER Communication wishes you a happy and healthy New Year.

A blast of heat for ITER’s plasma-facing components

The largest facility in the world capable of testing the ITER divertor’s plasma-facing components began operation in October at the Efremov Institute in St. Petersburg. A series of high-heat flux tests were performed on the first full-scale prototype of the divertor outer vertical target (see related video), which had been manufactured and delivered by the Japanese Domestic Agency.

ITER’s divertor components will be manufactured by the European, Japanese and Russian Domestic Agencies. These heat-capturing elements will be in direct contact with the plasma—a first barrier that will withstand the main heat flux from plasma during operation. With plasma temperatures of up to 150 million °C and an expected heat load on the divertor surface up to 20 MW/m2, the components under test have challenging requirements to meet.

„The inner and outer divertor targets are the most highly loaded components of the ITER machine,” says the leader of the Tungsten Divertor Section Frederic Escourbiac. „The aim of this testing is to verify the thermal performance of the plasma-facing component, and to make choices about materials and technology before the manufacturing phase.”

The ITER Divertor Test Facility in Russia was established following the signature in February 2010 of the Procurement Arrangement for the High Heat Flux Testing of ITER’s Plasma-Facing Components. In the vacuum chamber of this unique test facility, an 800 kW electron gun focuses its heat directly on the target, exposing the materials to the same heat load expected during normal operational conditions in the ITER machine.

„This first test series was remarkable in a number of ways,” says Frederic. „It was the maiden run for the ITER Divertor Test Facility, allowing our colleagues at the Efremov Institute to verify that all was functioning as planned and to work out the initial kinks. For the divertor program, it was the first opportunity to demonstrate that our scale one components can withstand the demanding thermal conditions of the ITER machine.”

The results of the three-week test run are currently under the scrutiny of Frederic, ITER Technical Engineer Andrey Fedosov, and colleagues at the Russian and Japanese Domestic Agencies, and will be reported early in the new year.

Click here to view the video on "High heat flux testing of plasma-facing components" produced by ITER Russia.

EUR 83 million contract signed for Liquid Helium Plant

The ITER Tokamak will rely on the largest cryogenic plant (cryoplant) infrastructure ever built. Three liquid helium plants, working in parallel, will provide a total average cooling capacity of 75 kW at 4.5 K and a maximum cumulated liquefaction rate of 12,300 litres/hour.

On Tuesday, 11 December, ITER Director-General Osamu Motojima and the Managing Director of Air Liquide Advanced Technologies, Xavier Vigor, signed the contract for ITER’s three identical liquid helium (LHe) plants. The contract comprises the design, manufacturing, installation and commissioning of the LHe plants, which are adapted to the long-term, uninterrupted operation of the ITER Tokamak. The contract is worth EUR 83 million.

The cryoplant and cryo-distribution system will supply cooling for the ITER superconducting magnets to confine and stabilize the plasma. They will also provide the refrigeration for the cryosorption panels that are necessary to evacuate the helium ashes stemming from the fusion reaction and to assure the required vacuum for the cryostat and the vacuum vessel. All these users require helium cryogen at different temperature levels ranging from 4.5 K, to 50 K and up to 80 K.

The key design requirement is to cope with ITER’s large dynamic heat loads ranging from 40 to 110 kW at 4.5 K mainly deposited in the magnets due to magnetic field variation and neutron production from deuterium-tritium fusion reactions. At the same time, the system must be able to cope with the regular regeneration of the cryopumps.

Manufacturing of the LHe plant main components will start after design finalization in 2014. The first compressor station will be delivered at the end of 2015 and the LHe plants will be ready for the cool-down of sub-systems in 2018.

„This is a major milestone not only for the cryogenic system but for the whole project,” said the Head of the ITER Plant Engineering Division, Luigi Serio. „The contract covers the principal component that will drive the cool-down of the machine, seting the pace toward First Plasma.”

„We are very happy and excited to participate in the great ITER adventure,” Xavier Vigor said. „Be assured that we, the team from Air Liquide, are fully committed to making ITER a success.”

Air Liquide is the world leader in gases for industry, health and the environment, and is present in 80 countries with 46,200 employees. Oxygen, nitrogen, hydrogen and rare gases have been at the core of Air Liquide’s activities since its creation in 1902. In 2011, the Group’s revenues amounted to EUR 14.5 billion, of which more than 80% were generated outside France.

In Padua, the Neutral Beam Test Facility is progressing

Progress on the Neutral Beam Test Facility, PRIMA, was reported this week by the European Domestic Agency F4E. Hosted by Consorzio-RFX in Padua, Italy, this facility under construction will test ITER’s large and powerful neutral beams in advance of operation.

The Neutral Beam Test Facility (NBTF) will host the prototypes of the ITER Neutral Beam Injector, which will be tested and developed there. The NBTF will host two independent test beds, namely SPIDER (Source for Production of Ion of Deuterium Extracted from Radio Frequency plasma) where the first full-scale ITER ion source will be tested and developed with an acceleration voltage up to 100 kV; and MITICA (Megavolt ITER Injector & Concept Advancement) which will be the first 1:1 full ITER injector aiming at operating up to the full acceleration voltage of 1 MV and a full power (16.5 MW).

Three procurement contracts were awarded during the last months for the manufacturing of NBTF components. The contract for the SPIDER beam source and vacuum vessel, worth approximately EUR 7.5 million EUR, was awarded to a European consortium formed by Thales (France), Galvano-T (Germany) and CECOM and Zanon (Italy). The contract for the NBTF cooling plant system, which will evacuate 70 MW of heat from the SPIDER and MITICA test beds, was awarded to the Italian company, Delta-ti Impianti S.p.A (EUR 8 million).

And finally, a EUR 2.5 million contract was signed for the vacuum and gas injection plant with Angelantoni Test Technologies (Italy), covering the design and construction of the gas injector that will provide the deuterium and hydrogen gas and the vacuum system that will pump (and deter) the gas from spreading.

Procurement of the main industrial contracts for SPIDER will be concluded with the award of the contract for SPIDER’s high voltage deck and transmission line, currently in its final stages. From 2013 onwards, the remaining European contracts for MITICA will be awarded.

On site in Padua, the construction of the buildings for MITICA and SPIDER is progressing. This construction is funded by Italy, as part of its commitments as Host to the NBTF.

Read the full report here.

Civil engineering contract will change platform face

The ITER site is set to go through one of its biggest transformations, following the signature by the European Domestic Agency F4E of a contract for site infrastructure works with COMSA EMTE.

Under this contract, for a value of EUR 35 million, a variety of civil engineering works such as lighting, drainage, special foundations, roads and trenches will be carried out. Eighty people will be deployed on the ITER site in order to ensure the coordination of the activities and reconfigure the 500,000 m² that will be directly affected by the works.

The civil engineering works carried out through this contract will deliver to the ITER site a fully integrated drainage system (process discharges, precipitation drainage and sanitary drainage), outdoor and indoor lighting, a water management system, service trenches for networks between buildings, roads and parking areas, and special foundations to support equipment and site installations.

A components cooling water network will be built to transfer heat from the systems for heat removal, operating side by side with the heat rejection system that will buffer heat loads during operation through an open loop system consisting of cooling towers, cold and hot basins, water pumps, valves, sensors and interconnected piping.

Read the full story on the F4E website here.

"Low-voltage" review opens way to contracts

Coil instrumentation in ITER consists of some 3,000 sensors whose function is to monitor the essential parameters of magnets during ITER operation.

A EUR 25 million package, coil instrumentation forms one the few direct purchases of the ITER Organization and the only fund procurement of the Magnet Division. The components will be delivered by the ITER Organization to the Domestic Agencies involved in coil procurement.

Cryogenic and mechanical instrumentation components („low-voltage” components) account for about one-third of the package’s value. Measuring temperature, displacement, strain, and deformation, the low-voltage sensors are critical. The Head of the Magnet Division, Neil Mitchell, explains: „These components cannot be maintained once they are installed. If one fails, it is lost. Of course there are redundancies, but we have to do our best to guarantee they will operate for 30 years in the harsh cryostat environment.”

On 13-14 December, all of the low-voltage components were reviewed by a panel that included members of the different ITER departments and directorates, specialists from the Domestic Agencies, and also internationally reputed external experts.

This was the third Manufacturing Readiness Review organized by the ITER Magnets Division over the last two months. The first one was conducted on the safety class quench detection system on 23 October; the second on 29-30 November for investment protection quench detection and related high voltage components.

Last week’s low-voltage review panel was chaired by Michel Huguet, a major figure in the history of the ITER project who joined fusion research in 1969 at CEA, spent 19 years at JET, and eventually headed the ITER Joint Work Site at Naka (Japan).

„The panel members were quite satisfied—I could even say impressed—by the quality of the work accomplished. Processes and strategies appear to be heading in the right direction.”

Now that the results of the qualification tests have been reviewed (ITER uses laboratories located at CERN) the next step is to release the contracts for low-voltage components, which should be accomplished in the first half of 2013.

Romanelli sees JET as "main risk mitigation" for ITER

On the afternoon last year when the European tokamak JET attempted first plasma after an 18-month shutdown, Associate Leader Francesco Romanelli remained in his first-floor office. „I wasn’t expecting the machine to perform so faultlessly on its first attempt,” he later explained. „Besides, things had a way of going wrong when I entered the room, so maybe it was better after all.”

That anecdote and others were related by Romanelli at last week’s Inside ITER seminar, during which he gave a first-hand overview of the ITER-like wall campaign that has been running at JET since that first (very successful) day back in August 2011. Three thousand installable items and 16,000 tiles had been replaced in the machine (non-metal carbon tiles were replaced by the metals beryllium and tungsten) to equip JET with the same materials mix chosen for ITER.

Romanelli reported in detail on the experimental results so far: demonstration of low fuel retention, tungsten divertor successfully tested, observations related to the dynamics of disruptions …

„Overall, the operation of the ITER-like wall has been easier than expected, giving us the confidence that the fusion community is making the right choice for ITER. We see JET as the main risk mitigation measure in support of ITER.”

The European Fusion Development Agreement is already looking ahead to other roles for JET—developing plasma scenarios in ITER-relevant configurations and testing the compatibility of the wall with the use of tritium. „JET can provide unique input in a number of technical and operational areas.”

David Campbell, director of ITER’s Plasma Operation Directorate, agrees: „The crucial ITER-like wall experiment will give us insight—ahead of ITER operation—as to how fusion plasmas will behave in the presence of the plasma-facing mixture that we’re planning to use in ITER.”
For more on JET’s ITER-like wall campaign, visit the EFDA-JET website.

ITPA decides on research priorities for 2013

Last week, a key meeting for the implementation of ITER physics R&D took place in the new Council Chamber. The Joint Meeting of the International Tokamak Physics Activity (ITPA) Coordinating Committee and the International Energy Agency Implementing Agreement (IEA IA) on Co-operation on Tokamak Programmes (CTP) is an annual gathering of senior representatives of the ITER Member fusion communities, the ITPA Topical Group leadership and program leaders from the major fusion facilities.

The 56 participants that had travelled from the ITER Members joined 12 from the ITER Organization for the meeting. In his opening remarks, ITER Director-General Osamu Motojima welcomed the participants, outlined the key priorities of the Unique ITER Team in relation to ITER construction, and underlined the major physics R&D needs. David Campbell, director of the Plasma Operation Directorate, gave an overview on the issues of physics R&D that are critical to the design and development of the ITER Research Plan.

Among these priorities are: the understanding and control of Edge Localized Modes (ELMs); disruptions and runaway electrons (and their mitigation); H-mode accessibility; use of all-metal plasma-facing components; the behaviour of tungsten impurities; tritium retention; dust; and power scrape-off layer (SOL) thickness.

The chairs of the seven ITPA Topical Groups reviewed the progress made in 2012 and proposed an experiment plan for 2013, focusing on the urgent issues for ITER. The Chair of Divertor and SOL Physics Topical Group, Emmanuelle Tsitrone, coordinated a special discussion session on the plan for joint research focusing on the comparison of divertors with carbon and tungsten plasma-facing components.

On the basis of high-priority research topics for ITER and the experimental capabilities of current fusion facilities, the facility program leaders decided on the priorities for each proposed experiment within their experimental programs for 2013. David Campbell commented, „I would like to thank ITPA for the continuing support of ITER R&D activities. We regard ITPA as a very important component of the ITER project and a critical part of our physics R&D program, providing a great deal of input to the physics design basis for the completion of the ITER design—a high-priority activity at the moment.”

Exploring plasma science advances

The latest advances in plasma physics were the focus of more than 1,000 scientists from around the world who gathered in Providence, R.I., from Oct. 29 through Nov. 2 for the 54th Annual Meeting of the American Physical Society’s Division of Plasma Physics (APS-DPP). Papers, posters and presentations ranged from fusion plasma discoveries applicable to ITER, to research on 3D magnetic fields and antimatter. In all, more than 1,800 papers were discussed during the week-long event.

Researchers from the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) reported on experiments and computer simulations related to tokamak confinement and a variety of other research interests. These included specialized areas such as laboratory and astrophysical plasmas, where PPPL physicist Hantao Ji was prominent as a topic chair and speaker at a tutorial session.

Members of the Laboratory’s National Spherical Torus Experiment Upgrade  (NSTX-U) team gave a tutorial and three invited talks. Physicist Dennis Mueller presented the tutorial on „Physics of Tokamak Plasma Start-up.”

The Laboratory sent 135 physicists, science educators and graduate students to the meeting and saw some of its research highlighted in news releases on the APS-DPP website. Of the 14 papers highlighted in this manner, seven came from PPPL.

The meeting focused considerable attention on boundary physics and plasma-material wall interactions, an area of growing emphasis at PPPL.  Dennis Whyte, a professor of nuclear science and engineering, at the Massachusetts Institute of Technology, presented a major review of the subject to a plenary session.

Invited speakers on the topic of plasma-wall and impurity physics included PPPL scientists Filippo Scotti and Dick Majeski, principal investigator for the Laboratory’s Lithium Tokamak Experiment (LTX). PPPL physicists Michael Jaworski and Igor Kaganovich participated in a session on plasma-wall interactions, with Jaworski serving as chair and Kaganovich giving the first invited talk in the session.

 The importance of boundary physics has been recognized in innovations like the so-called snowflake divertor, which limits the heat on tokamaks’ inner walls. The divertor, developed by researchers at PPPL and the DOE’s Lawrence Livermore and Oak Ridge national laboratories, won an R&D 100 Award in June from R&D Magazine. The device „reduces both the power flux on plasma-facing components and the influx of impurities into the core plasma,” said PPPL physicist Robert Kaita, the head of diagnostics and physics operations for the National Spherical Torus Experiment Upgrade (NSTX-U), and co-principal investigator for the LTX.

Considerable interest also was shown for inertial confinement fusion experiments at the National Ignition Facility (NIF) at the DOE’s Lawrence Livermore National Laboratory. Speakers noted that producing fusion by heating a capsule producing energy with high-powered lasers was proving more difficult than expected. NIF scientists now seek to develop a more detailed understanding of the physics of this process in order to achieve ignition.

Link to APS Press Releases

A spectacular panorama

SFR technician Sylvain Couturier took this spectacular panoramic shot as he surveyed possible locations for a permanent cellular radio tower to relay cell phone signals throughout the ITER site.

Taken from a height of 40 metres, the panorama stretches from the worksite guard post on the left all the way to the twin 81 and 82 buildings (formerly JWS 2 and 3) to the right.

The ongoing work on the drainage networks is clearly visible at the centre of the image, as are the reinforcement activities for the modular building foundations (offices, canteen and infirmary) that should be completed by March 2013 (centre right). © Sylvain Couturier

633 vacuum vessel forgings shipped to Korea

In the early hours of Monday, 29 October 2012, the last of 633 massive stainless steel forgings for the ITER vacuum vessel left the KIND premises in rural Gummersbach, Germany. Their destination: Hyundai Heavy Industries in Ulsan, South Korea.

The forgings, made from highly refined F316L(N) IG steel, will be used for the construction of the first two sectors of the ITER vacuum vessel. The vacuum vessel is a hermetically-sealed steel container that contains the fusion plasma and acts as a first safety containment barrier. The manufacturing of the vessel is divided between Europe, which will supply seven sectors, and Korea, which will supply two sectors.

"We are very proud of being able to deliver these very special and tailor-made components for ITER on time,” said Markus Kind, commercial managing director of the family-run company that is well-known for its experience in custom-made forgings (whether the 2,000 pieces manufactured for the Large Hadron Collider at CERN or the 15-ton propeller shaft of a super yacht).

It took two full days to load the precious goods weighing 360 tons into 20 shipping containers.

The cargo Don Giovanni is now headed for Ulsan, South Korea, where the fabrication of the first two vacuum vessel sectors is in full swing. 

"The start of vacuum vessel sector welding is a historical moment for the ITER project as it marks the manufacturing of the first fully licensed vacuum vessel for a fusion reactor in the word,” said Alexander Alekseev, director of the ITER Tokamak Directorate during a recent visit to the Hyundai facility. „The Korean Domestic Agency and Hyundai Heavy Industries have done a great job. I know that it was not easy … I appreciate very much the work done. This is a good start; we are quite confident that Korea will deliver all the sectors according to schedule.”

Achieving mission success

The new Communications Manager for the US Domestic Agency, Mark Uhran, spent some time at ITER this week getting immersed in the specificity of ITER challenges, visiting the site, and improving his understanding of the details of the ITER project.

„My understanding is very young … barely four months old … however I have been following the progress of fusion plasma R&D from a distance for several decades now.”

Although as a young engineer he began his career in the field of renewable energy, Mark took a lengthy detour over to the space industry. For 28 years he held positions of increasing responsibility at NASA, culminating as program director for the International Space Station (ISS) Division at NASA Headquarters.

Of nearly three decades as part of the ambitious ISS program, following the project from conception through delivery, Mark retains many lessons—lessons that he sought to share with the ITER community during an Inside ITER seminar last week.

„For the first time in human history, we’re now finding industrialized nations forming partnerships to design and build complex, technological assets for which no nation alone can bear the cost or the risk. Perhaps the lessons learned from ISS will be of use to us all, as we pursue yet another grand challenge through international partnership.”

Mark spoke of the challenge of maintaining public support for complex, long-term projects through the inevitable changes in government priorities, economic conditions, and the policy-making environment. „The ISS is now up and running and I’m confident that the future R&D potential of the Space Station is at least as great as the engineering achievements already in hand. But it took 25 years to get to this point … Along the way it was important to show progress in incremental steps, to celebrate the unprecedented scientific and technical merits of the intermediate steps as well as the final goal.”

He also underlined the challenge that it had been for the ISS program to integrate subsystems delivered by each Partner that, in the end, had to become interoperable. „The challenge did not end with the delivery and successful acceptance testing of each component … that’s when the challenge began,” Mark stressed. „The delivering partner stayed actively engaged until the whole system was operating according to specifications. We called this 'sustaining engineering.’ It was by treating all ISS Partners as perennial stakeholders that, in the end, each one took pride in their ongoing contributions to the success of the ISS team.”

Mark took the audience back to the early days of the ISS program, recalling the „chaotic period” around the end of the preliminary design phase when people from around the world—speaking different languages, employing different design standards, and advocating different approaches to qualifying system performance and reliability—had gathered to build a permanently crewed, full service space station in low-Earth orbit.

„The sheer volume of requirements was almost overwhelming,” says Mark. But with the rigorous management of the change request process and the successful organization of the systems engineering and integration function („NASA’s 'forte'”) the program advance successfully. „That’s why I’m personally so excited about human progress in Very Large-Scale International Systems Integration (VLISI). The state-of-the-art is really advancing globally.”

One last word to the assembled crowd: „NASA had evolved a culture of testing in order to avoid schedule stalls along the way. This testing culture turned out to be invaluable to the ISS program, where we had systems and elements from around the world that were seeing one another for the first time in space. There was no room for error. We implemented a costly, but very effective multi-element integrated testing capability that exposed the potential 'glitches’ that would have cost tens of millions had we encountered those faults for the first time during operations.”

The ISS partners were successful in building the Space Station—an absolutely Herculean effort—because of teamwork and risk management, Mark concluded. Before ending with a quote from Henry Ford, the father of the modern assembly line: „Coming together is a beginning; keeping together is progress; working together is success.”

Crowning the cryostat from below

Columns are as old as civilization: for thousands of years, they have provided architects and engineers with a simple and sturdy solution to support heavy loads while leaving room to move around on the ground below.

This traditional and reliable solution was to be implemented in ITER: a circular arrangement of 18 steel columns was to support the cryostat ring—the thick steel component that acts as a mechanical interface between the combined mass of the cryostat and Tokamak (25,000 tons) and the Tokamak Complex basemat.

Columns do a great job supporting large, static loads. However under particular circumstances during ITER Tokamak operation, mechanical, magnetic, or thermal loads, singly or combined, could add up to generate considerable stress on the columns.

In the case of a vertical displacement event, for instance, the Tokamak could „up-lift”; in the case of a cryostat ingress cooling event, the cryostat could „shrink”…

Once refined, models and simulations showed that under certain conditions the load transfer to the basemat by way of the columns was not totally satisfying. For ITER Safety Security and Quality (SQS), this was clearly a potential safety issue. „As the Tokamak Complex basemat could not be modified, it was imperative to develop an alternate solution to the columns. In this, the expertise of Design Integration Section was fundamental,” explains head of the ITER Licensing Cell Joëlle Elbez-Uzan.

Thus began, early in 2012, a ten-month collaborative effort involving ITER’s Safety, Quality & Security; Building and Site Infrastructure; Technical Integration; Cryostat; Assembly; Safety; and Magnet teams, as well as the European Domestic Agency F4E and their Architect Engineer, Engage.

„The light eventually came from  Engage’s design project leader, Peter Sedgwick,” recounts ITER’s Nuclear Buildings Section leader Laurent Patisson. „He suggested we mobilize the resistance capacity of the three-metre-thick concrete bioshield wall that surrounds the cryostat—something we had not fully investigated …”

The exceptionally thick and strong bioshield, which stands approximately three metres away from the cryostat, held the solution indeed. „The idea is to replace the 18 steel columns with a concrete 'crown’. Every 20 degrees, the crown would be connected to reinforced concrete walls radially anchored into the bioshield. It’s a clever and efficient solution to distribute the efforts evenly…”

Faced with a similar problem, the architects of Notre Dame Cathedral, in the 13th century, developed a similar solution. „By positioning flying buttresses at regular intervals around the Cathedral’s nave, they were able to evenly distribute the loads of the edifice’s walls, explains Joëlle.

In the ITER Tokamak however, every design modification is bound to impact other components. Designers soon realized that one of the radial walls connecting the crown to the bioshield was competing for space with the magnet feeder for poloidal field coil number 4.

An early option called for compensation by way of a set of concrete beams. „However such a singularity in the crown support system would have made the structural capacity demonstration difficult,” explains Laurent.

Working closely with the Magnet and Technical Integration Divisions and the Building & Site Infrastructure Directorate, a solution was eventually reached, which resulted in the proposed cryostat support system regaining its symmetry.

All in all, as stated in the preliminary assessment on the capacity of the new cryostat support, the new design „could result in a more integral and compact solution, with many potential advantages from a mounting and constructability point of view, as well as from a global structural capacity perspective.”

The cryostat ring and the concrete crown that supports it would be connected by way of an arrangement of 18 spherical bearings acting like ball-and-socket joints. Such bearings, which are also used in large bridges, allow for the smooth transfer of horizontal and rotational forces.

Needless to say, all these components will have to retain quality and functionality in a rather harsh environment, where radioactivity will be high and cold very intense—reaching -100°C in the vicinity of the cryostat ring.

ITER Safety Security and Quality and Buildings & Site Infrastructure are now preparing the Support Robustness Demonstration document, which will be submitted to the French Safety Authority (Autorité de Sûreté Nucléaire, ASN) in January.

When the Demonstration is validated, work will resume inside the Tokamak Seismic Pit where the 1.5-metre-thick Tokamak Complex basemat will be poured.

Deuterium from a quantum sieve

A metal-organic framework separates hydrogen isotopes more efficiently than previous methods

Deuterium is the heavy twin brother of hydrogen; however, it is more than 20 times rarer than identical twins. It accounts for only 0.015 percent of natural hydrogen and is twice as heavy as the light isotope.

There is no chemical difference between the two isotopes: both deuterium and ordinary hydrogen react with oxygen to form water. Its double mass allows researchers to lay a trail to elucidate chemical reactions or metabolic processes, however. They dispatch a compound containing deuterium into the processes and analyze in which conversion product it turns up. And this is only one of the tasks that deuterium fulfils in research. It may even become an inexhaustible and climate-neutral fuel in future.

This would be the case if nuclear fusion becomes so technically mature that energy is generated on Earth using the same process that also occurs in the Sun. This produces much less radioactive waste than nuclear fission.

In a cooperation established within the DFG German Research Foundation’s priority program „Porous Metal-Organic Frameworks” (SPP 1362), a team of scientists from the Max Planck Institute for Intelligent Systems in Stuttgart, Jacobs University Bremen and the University of Augsburg have now been able to enrich deuterium contained in hydrogen more efficiently than with conventional methods.

The findings are reported in the journal Advanced Materials. The researchers discovered that a certain metal-organic framework, abbreviated MOF, absorbs deuterium more easily than common hydrogen at temperatures below minus 200 degrees Celsius.

Read more here. 

ITER is well underway

The Eleventh ITER Council convened last week at the ITER site for a two-day meeting that brought together the high-level representatives of the seven ITER Members.

As approximately 100 people took their places in the solemn setting of the new Council Room, Director-General Osamu Motojima welcomed the participants, adding, „I would like to take this opportunity to thank the Members, in particular Europe, the Host Party, and Agence ITER France for providing the project with the ITER Organization Headquarters building where staff is nearly fully installed.” 

The Council noted the strong measures that have been taken by the ITER Organization and the Domestic Agencies to realize strategic schedule milestones and to develop new corrective measures for critical systems such as buildings, the vacuum vessel, the cryostat, and the superconducting magnets. Delegates urged further corrective actions to improve schedule execution and to seek additional savings.

Delegates welcomed the integrated project management approach proposed by the ITER Organization to enhance collaboration between the ITER Organization and the Domestic Agencies, an approach, according to Director-General Motojima, to „cooperate even more closely for the implementation of ITER.”

The ITER Council also celebrated the recent major licensing milestone for ITER, the strong pace of construction activities at the ITER site, and the manufacturing activities well underway in all ITER Members.

The next ITER Council meeting is scheduled to take place in Japan in June 2013.

Click here to view the photo gallery of the Eleventh ITER Council
Read the Press Releases in English and in French.

"ITER is well underway"

The Eleventh ITER Council convened last week at the ITER site for a two-day meeting that brought together the high-level representatives of the seven ITER Members.

As approximately 100 people took their places in the solemn setting of the new Council Room, Director-General Osamu Motojima welcomed the participants, adding, „I would like to take this opportunity to thank the Members, in particular Europe, the Host Party, and Agence ITER France for providing the project with the ITER Organization Headquarters building where staff is nearly fully installed.” 

The Council noted the strong measures that have been taken by the ITER Organization and the Domestic Agencies to realize strategic schedule milestones and to develop new corrective measures for critical systems such as buildings, the vacuum vessel, the cryostat, and the superconducting magnets. Delegates urged further corrective actions to improve schedule execution and to seek additional savings.

Delegates welcomed the integrated project management approach proposed by the ITER Organization to enhance collaboration between the ITER Organization and the Domestic Agencies, an approach, according to Director-General Motojima, to „cooperate even more closely for the implementation of ITER.”

The ITER Council also celebrated the recent major licensing milestone for ITER, the strong pace of construction activities at the ITER site, and the manufacturing activities well underway in all ITER Members.

The next ITER Council meeting is scheduled to take place in Japan in June 2013.

Click here to view the photo gallery of the Eleventh ITER Council
Read the Press Releases in English and in French.