First four levels of Tokamak Complex now defined

The heart of the ITER facility will be the Tokamak Complex, comprising the Tokamak Building, the Diagnostic Building, and the Tritium Plant.

The seven-storey Complex measuring 118 by 80 metres and towering 57 metres above the platform will contain more than 30 different plant systems including cooling systems and electrical power supplies, all having physical as well as functional interfaces. As you can tell from the configuration drawing there won’t be much extra room for manoeuvring. The house is pretty busy!

In order to make sure that all the necessary pipes, ducts, structures, cable trays and penetrations are correctly defined before the pouring of the concrete, a Building Integration Task Force was created in April last year to go through the building floor by floor. All the required documentation has now been delivered for the basement level (B2), the lower level (B1) and the equatorial level (L1) according to the agreed schedule with the European Domestic Agency Fusion for Energy and the Architect Engineer ENGAGE. The upper level (L2) has also been reviewed and the data files will be handed over by the end of this month.
The configuration for each level was reviewed in compliance with the safety files and the installation and assembly feasibility of the systems and components. The design also respects the requirements on the civil works such as radiation shielding, fire protection and sectorization, and confinement leak tightness.

For the Level B2 slab, the detailed design of the rebar arrangement will be completed by F4E’s designer Engage by December followed by the review of all the embedded steel plates that will be cast into the concrete to support the heavy loads.

About 55,000 such plates have been identified and tagged in the floors, walls and ceilings of the Tokamak Complex. The review will focus on the exact position of each plate with respect to the concrete rebar grid. Furthermore, for each plate the plate type and anchoring system need to be confirmed. Following the finalization of the design in March 2013, pouring will begin on the B2 slab. This process will continue for the remaining levels of the Tokamak Complex.

The ITER circles of support

In terms of the number of individuals devoting their time and energy to the realization of ITER, there are of course the employees and contractors of the ITER Organization, currently estimated at 900 people. But this nucleus is surrounded by concentric circles of support without which the project couldn’t succeed: the ITER Members; the ITER Council and its advisory bodies; the Domestic Agency teams and their manufacturing partners; and finally fusion associations all over the world.

A representative of this last category visited ITER last week as a guest lecturer for the Inside ITER seminar series. Dr. Rudolf Neu from the European Fusion Development Agreement (EFDA) is known as „Mr. Tungsten” in the fusion world. Closely involved with the ASDEX wall upgrade and the JET ITER-like wall, Mr. Neu is currently in charge of EFDA’s ITER Physics Department where he coordinates the research program in preparation for ITER’s experimentation phase.

„EFDA activities are strongly aligned with ITER needs,” said Dr. Neu. „Our fusion associations pool resources and share results … results which are then extrapolated for ITER.” Thirty fusion associations are part of the EFDA family, with responsibility for 14 fusion experiments that are currently operating or under construction. 

Among the exciting projects going on in Europe is JET’s ITER-like wall experiment: „This is an experiment that uses the ITER material mix for the first time in a tokamak. We have already had manifold unexpected results from this experiment that we hope will give us new physics insights. This is truly an important experiment for ITER.”

Dr. Neu also updated the audience on the Fusion Roadmap which draws out the step-by-step aims of Europe’s fusion program, with the final goal of fusion electricity by 2050. „The European Fusion Roadmap sees ITER as the key facility for the development of fusion energy.”

The benefit is mutual, according to lTER Director-General Osamu Motojima: „The European Union’s high-level domestic program in fusion is very important for the ITER project. Having such support is very encouraging for us all.”

Dealing with space constraints in ITER’s Data Centre

Every day ITER accumulates megabyte upon megabyte of data that must be safely stored, organized and made accessible to thousands of users.

As a consequence, ITER needs the equivalent of a very powerful computer equipped with a very large and fast hard disk.
Early last week the barebones of this computer were delivered to the Headquarters building, consisting of 25 tons (nine truckloads!) of racks, cooling units, power distribution modules and batteries that will host the hundreds of disks and processing units of the ITER Data Centre.

Because of space and budget constraints a lot of technical creativity had to go into the design of this new Data Centre. „An early plan was to have an 800-square-metre room, later reduced to 300, and to equip it with EUR 3.5 million worth of hardware,” explains IT System Administration Expert Cédric Chaumette who managed the project.

Two years after the original plans were drafted, the Data Centre’s surface has shrunk to 120 square metres and its budget to EUR 1 million. However, even within these reduced parameters, IT managed to design a more efficient, „greener” and scalable installation that will serve ITER for the whole duration of its construction life cycle.

How did they do it? Implementing a standard architecture—characterized by low-density racks and in-room cooling—was impossible. „The space constraint was very high. There was no way we could evacuate the heat generated by the 300 KW of IT power the installation requires. Rack cooling was a major problem.”

Racks must be cooled because, beyond a certain temperature, processors and hard disks are at risk. In the case of standard architecture, cooling is achieved by circulating cool air from below a raised floor and dissipating it throughout the room. This only works, however, when the available space permits a low rack density—not the case for ITER’s 120-square metre Data Centre.

The solution Cédric and IT came up with is an innovative design called „hot aisle containment,” where cooling devices are interspaced with computer racks („in-row cooling”) and cool air is forced throughout the whole height of the racks. In this new medium-to-high rack density arrangement, the cost is divided by three and the storage and processing capacity becomes scalable to the ever-growing needs of ITER.

The new ITER Data Centre is scheduled to be operational in March 2013.

Click here to view an animation of the ITER Data Centre floor plan. 

Celebrating Europe and the Licensing Decree


The ITER community had two events to celebrate last Friday 23 November: first, the granting of the ITER Organization’s nuclear licensing decree, which was the subject of an all-hands meeting in the morning, and second—ITER Member Day. This third ITER Member Day of the year was the occasion to visit the culture and traditions of Europe, in the airy setting of ITER’s brand-new cafeteria with a capacity for 1,000.

„Today, we should celebrate together the milestone that has been achieved,” said Director-General Osamu Motojima in his opening presentation in the ITER amphitheatre. „ITER is now formally a nuclear operator, and the first fusion device that qualifies as a nuclear installation.”

For the crowd assembled, Deputy Director-General for Safety, Quality & Security Carlos Alejaldre had the following words: „Those of us who have been working for fusion for a long time have always said that fusion is safe, but up to now there had never been an independent evaluation of that safety. For the first time, an independent body of experts has come to the conclusion—and made the official recommendation—that 'You have the green light to go ahead, because you have shown that your project is safe.'”

On 10 November, the French government published Decree 2012-2048 authorizing the creation of the ITER nuclear facility. Coming as it did after a very long and difficult examination process, lasting for over two years, the decree represents a landmark achievement—for ITER, of course, but not only. „My personal view,” said DDG Alejaldre, „is that this licensing milestone is also an important achievement for the fusion development program. We are beginning to talk about the next step after ITER; the implications of the event that we are celebrating today will be felt long into the future.”

To put the event in perspective, he told the audience, „Imagine for one moment that the ITER project didn’t get the decree … What would have happened? Everything would have been stopped.”

The positive conclusion of ITER’s licensing process is indeed cause for celebration, marking the end of long, thorough and sometimes gruelling examination process. „The Nuclear Safety Authority in France is one of the most, if not the most, demanding in the nuclear world, and certainly one of the most prestigious,” stressed DDG Alejaldre. „To have succeeded in our endeavour is a consequence of everybody in this room, and also of people not in this room today.”

Before the crowd convened for the buffet lunch waiting just a few doors away, he reminded the ITER community that ITER’s new status comes with responsibility. „This decree is a binding contract between the French state and the ITER Organization as nuclear operator. It is a contract that we cannot break.”

Click here to view more pictures of EU Day celebration

A fusion nomad


Tough luck: six months after Carlo Sborchia submitted his thesis on „Thermo-mechanical behaviour of fuel rods in case of a loss of coolant accident in Pressurized Water Reactors,” Chernobyl’s Reactor #4 went up in a cloud of radioactive smoke. As a consequence, Italy decided to halt its four operating nuclear plants and to phase out two projects already well underway.

For the young nuclear engineer, job prospects at home looked rather bleak. However, like for many other Italian nuclear engineers Chernobyl was Carlo’s luck: while fission energy was becoming a thing of the past in Italy, other ventures elsewhere could make use of his skills. For Carlo of course, this meant leaving his native Tuscany— something which, with the exception of a couple of trips to Rome, he had never done in his life.

As if to compensate for the 26 years he had spent in and near Piombino, the small town that faces the island of Elba (of Napoleonic fame), Carlo commenced a nomad’s existence in 1986, never to come back to Italy: CERN first, then one and a half years at the Sultan group in PSI Villigen, Switzerland and a first encounter with fusion through the NET project; five years at JET as a structural analyst, where he was recruited by Euratom; six and a half years with the ITER joint central team at Naka in Japan, then with EFDA in Garching, Germany; two and a half years in Greifswald as Head of the Superconducting Group of the Wendelstein 7-X stellarator; a first one-year stint at ITER in Cadarache in 2007; followed by five years with Fusion for Energy in Barcelona as Head of the Magnet Group, responsible for 25 percent of the ITER magnet system procurement.

Over the course of his peregrinations—almost three decades' worth—the young engineer who specialized originally in structural analysis graduated along the way to become an expert in magnets, accumulating experience in mockup design and manufacturing, procurement management, installation and, perhaps most important of all, learning to drive and motivate a team in times of success and in times of crisis.

Carlo’s story is a perfect illustration of what the „worldwide fusion family” is all about: the recently appointed head of the ITER Vacuum Vessel Division has worked with most of the people that are part of ITER today, people who were his neighbours, colleagues and friends in Culham, Naka, Garching or Greifswald.

How will a „magnet man” deal with the complex issues facing the ITER vacuum vessel? „A vacuum vessel is not a foreign object to me,” explains Carlo. „I’ve actually spent six months inside JET’s vacuum vessel—not many people have had that experience. Sure, I’ve been a 'magnet man' for the best part of my career but, in reality, by taking on this responsibility at ITER I’m going back to my original calling which is nuclear engineering. A vacuum vessel is about just that: structure, welding, loads …”

Although he talks fast and at length, Carlo knows the importance of listening. „I’ve been here three days,” he said last week, „and what I basically did during that time was listen. You can’t motivate your people if you don’t listen to them, if you’re not present, if you don’t develop a personal relationship with them. And in the years to come, we’ll need a highly motivated team to tackle the technical challenges ahead.”

A family reunion

In mid-January 2009, communication between the „old” ITER Headquarters (presently building B 82) and the ITER offices located inside the CEA enclosure was made considerably easier by the opening of a Rotogate in the CEA fence—from that moment on, a driving distance of some two kilometres was transformed into a bucolic walk of a couple of hundred metres.

Last Friday 16 November, as the last offices on the CEAwere being vacated by ITER employees who had been assigned new offices within the ITER site, the Rotogate rotated for the last time.

For ITER Director-General Osamu Motojima, the event was significant. „This last passage through the Rotogate is a great opportunity to affirm the ITER Organization’s independent responsibility as a nuclear operator.” It was also the occasion to express ITER’s gratitude toward CEA Chairman Bernard Bigot, CEA-Cadarache Director Maurice Mazière, and Agence Iter France Director Jérôme Pamela, whose „great friendship, contribution and support” will not be forgotten.

As the Rotogate turned behind the last ITER staff member (CODAC network administrator Nicolas Pons), a new chapter opened in the history of the project. For the first time since the Joint Work Site opened in Cadarache in December 2005, the whole ITER family was „home at last.”


10 systems, 400 pumps pass Review

World experts on vacuum and fusion safety gathered last week at the ITER Headquarters for the Conceptual Design Review of the Vacuum Auxiliary Systems main delivery. „This is our most diverse Procurement Arrangement, covering 10 systems and including approximately 400 vacuum pumps situated all over the Tokamak Complex,” explained Vacuum Section Leader, Robert Pearce.

The design of the systems was presented in 60 presentations over 3 long days.  Liam Worth, review coordinator, expounds, „The review concludes many man-years of work by members of the ITER Vacuum team; preparations have been particularly intense over the last few months.” Such work led to a successful review and Review Chair Alastair Bell commended the Vacuum team on its high level of preparation.

Passing this Review will now allow the Vacuum teams to progress to issuing the Procurement Arrangement for the systems, which should be ready to be signed between ITER Organization and the US Domestic Agency (US-DA) early next year. „Excellent,” stated US-DA vacuum team leader Michael Hechler who attended the review with four other team members.


The expo that makes fusion accessible

After Bratislava, Vienna and Liège, the Fusion Expo has moved into the centre of Aix-en-Provence, France, receiving hundreds of curious visitors during its first week.

With accessible explanations on fusion science, ITER, and the next category of fusion device—the fusion power plant—the Fusion Expo is designed for the general public. The Expo is staffed by members of the ITER Organization, the Cadarache-based Institute for Magnetic Fusion Research (IRFM), and Agence Iter France.

„With the ITER project under construction only 40 kilometres away, there has been great interest in the Fusion Expo,” observed Michel Claessens, head of ITER Communication. „It has been a terrific opportunity to reach out to the local public and to communicate the importance of the world-scale energy project that is happening in their backyard.”

Four roundtable discussions have been programmed to address specific aspects of the project. At last Saturday’s session on „The Energy Challenge and Fusion,” Michel Chatelier, former head of fusion research at CEA; Jean-Marc Ané, a CEA physicist at Tore Supra; and Richard Pitts, senior scientific officer in the ITER Plasma Wall Interactions Section, spoke to a full house, presenting their vision of the future and how they saw fusion fitting into it.

Combined with the exhibition, such roundtables provide the public with an opportunity to voice their questions and concerns directly to the actors involved. In this respect, Saturday’s discussion was a great success.

The Fusion Expo is a travelling European exhibition funded by EFDA and the European Commission that has been operating since 2008 under the responsibility of the Slovenian Fusion Association.

You can visit the Fusion Expo through 28 November at the Office de Tourisme in Aix-en-Provence. Roundtable discussions (in French) are programmed on Tuesday 21 November, 4:00 p.m. („Provence, A Magnet for Scientific Excellence”) and Saturday 24 November, 4:00 p.m. („Fusion and ITER: Scientific and Technological Stakes”).

See also "The power of the Director-General" on the EFDA website.


ITER welcomes Desertec

It all started on Lake Geneva with a promise. During the dinner cruise marking the grand finale of this year’s Energy Security Congress, representatives of the ITER project and the solar energy project Desertec shared a table. Two ambitious endeavours set up to secure the world’s future energy supply through the power of the sun—one, by mimicking the process that powers the sun and other stars; the other by generating electricity from sun-drenched desert regions.

By the end of the evening, Oliver Steinmetz, one of the co-founders of Desertec who had (together with nine like-minded „brothers”) committed EUR 5,000 of his own funds to start the Desertec Foundation, promised that one day he would come to Cadarache to see the ITER project with his own eyes.

And so he did last week. After a crash course in fusion and ITER followed by a tour of the construction site, Oliver Steinmetz gave the first Inside ITER seminar in the new ITER amphitheatre.

The Desertec Foundation is an international non-profit collaboration of scientists, concerned individuals, and alternative-energy companies that believe that a combination of solar power from the world’s deserts and wind power can provide all the electricity society needs. The idea is driven by a simple equation: within six hours, the world’s deserts receive more energy from the Sun that humankind consumes within one year. 

„In order to meet today’s global power demand (18,000 TWh/year), it would suffice to equip about three thousandths of the world’s deserts with solar collectors,” Steinmetz maintains. That’s about 90,000 square kilometres of desert, shown as a small red square on Desertec’s map of the Sahara desert—the same red square that has become the Desertec logo.

But the Sun’s energy is not the only target of Desertec. Their concept calls for the utilization of all sorts of renewable energies wherever they are most abundant (i.e., coastal areas for wind).
_To_40_Tx_Combined with sophisticated heat-storage technology, the power supplied by solar-thermal power plants can be made available day and night, complementing fluctuating renewable energy sources such as wind power and photovoltaics. A low-loss, high-voltage direct current transmission grid would connect—across great distances—the production location with the centres of consumption.

For the EU-MENA region (Europe-Middle East-North Africa), the Desertec concept assumes, given the political will, that by 2050 a substantial portion of the electricity needs of the local markets and around 15 percent of European energy needs could be covered by power stations in the desert. This would entail estimated investments on the order of EUR 400 billion.

Before large-scale solar power plants and wind farms in North Africa and the Middle East with transmission grids reaching across to Europe become a reality, however, their technical feasibility must first be examined, the political course set, and the first reference plants initiated. This is why the Desertec Industrial Initiative (Dii GmbH) was founded in October 2009 in order to create the framework conditions to enable international trading in climate-friendly electricity as well as suitable investment incentives. Among the 13 founding members were the Deutsche Bank, Siemens, German energy giant RWE, and the second largest re-insurer, MunichRe.

The involvement of academic and research institutions in the EU-MENA region has since been promoted through the Desertec University Network (DUN) established in October 2010, which reunites universities and research facilities from Morocco, Algeria, Tunisia, Libya, Egypt and Jordan. Its aim: to contribute to the implementation of the Desertec concept.

At the end of his talk Oliver Steinmetz answered many questions on the maintenance of technology and the security of supply. "Delivering energy across borders—sometimes changing borders—is a matter of international cooperation and trust,” he concluded. Words that were not unfamiliar to the assembled ITER staff …

For more on the Desertec Foundation, see the project’s Red Paper.

Click here to download the pdf of the presentation.

Click here to watch the video of Inside ITER lecture.



Bringing it all together for DEMO

Experts at Culham Centre for Fusion Energy (CCFE) have carried out the first-ever integrated assessment of the life expectancy of materials in a full-scale fusion power plant design.

The study focused on the effects caused by the build-up of helium in fusion materials. When neutrons from fusion reactions hit the materials in reactor components, they trigger nuclear reactions that cause transmutation (the changing of elements to form new ones). Helium is one of the gases produced by such reactions. The accumulation of helium causes swelling and embrittlement of materials—leading to fracture—and is one of the factors expected to limit the lifetime of components in a fusion power plant.

Materials modellers Mark Gilbert and Sergei Dudarev, working with CCFE specialists in nuclear data and neutron transport (Lee Packer, Jean-Christophe Sublet, and Shanliang Zheng) have conducted a pioneering study in which a fusion power plant design was explored and assessed using an integrated computational model that gives a detailed prediction of the lifetime of components under helium embrittlement.

The results will help guide the choice of materials for the design of DEMO, the prototype power plant that will follow the ITER experiment.
„We found wide variations between the behaviour of different materials,” said Mark Gilbert. „The good news is that tungsten (the likely material for the 'divertor' plasma exhaust system in DEMO as well as ITER) shows low susceptibility to helium accumulation and embrittlement. However, in the iron of steels, for example, there is higher helium production in components bearing the brunt of neutrons from fusion reactions. The study highlights the need to develop materials with special microstructure, such as oxide dispersion strengthened steels that can resist the effects of helium accumulation without becoming brittle."

„We think the integrated approach we have adopted has worked well, and it will now help advance the EFDA materials program as a result.”

The results of the work are published in Nuclear Fusion 52 (2012) 083019.


An architect revisits his creation

An architect is like a surrogate mother, giving birth to a child who will be raised by someone else.

„There’s a feeling of being dispossessed,” said Laurent Bonhomme, as he walked the halls of the completed ITER Headquarters building last week.

Bonhomme, who is based in neighbouring Vinon-sur-Verdon, teamed with colleague Rudy Ricciotti from Marseille to design the office building that will progressively accommodate about half of the present ITER staff, housed in some 250 offices.

„Yes, he mused, it’s a strange feeling. The baby you’ve carried for more than two years is not yours anymore. Now I need to ask permission to visit …”

A veteran architect, Bonhomme is familiar with such „building blues”… it goes with the job. This time, however, the baby was special. „I’ve done several projects in the 50- to 80-office range but a 250-office building like the ITER Headquarters is quite exceptional in this region.”

What was also special for Bonhomme was to work in partnership with Rudy Ricciotti, one of the most creative (and provocative) architects of his generation. „Ricciotti and I, we represent the two extremes of this profession. His approach is very radical; mine is more down-to-earth, in line with the four principal constraints of the building process—functions, regulations, budget and schedule.”

Improbable as it was, the partnership was fruitful. Both men agreed on the essentials: using the shape of the building as a visual pedestal—”a horizontal monolith for the exuberant verticality of Tokamak Building” that will rise in the background.

„When you design a building,” says Bonhomme, „you must take into consideration how it will be seen from different angles and directions. In the case of the ITER Headquarters it was rather simple: basically, you have two important views, the one from the road to the northwest and the one from the platform to the south.”

As the view from the platform is a private one—only people working in the installation will be able to enjoy it—the architects opted for a rather rigorous, no-thrills facade. But on the contrary, Bonhomme considered that the 13,500 motorists travelling along the Vinon road every day should be treated to a more exciting visual experience—a „kinetic illusion” that is created by vertical slats running the full length of the facade.

While some of the building’s dwellers consider that these vertical slats are a nuisance ("prison bars” is a term that has been heard here and there …) Bonhomme explains that, as with a painting or a photograph, „a view needs to be framed,” especially in an office setting where concentration is important.

Architects can be tyrants, but only up to a point. „A successful building project is one that achieves a balance between the functionalities that the architect has anticipated and those that the user will develop.”

Take for instance the wooden window seats that run around the building’s patios: the architects' idea was to „add a different material to an environment dominated by glass and concrete.” They anticipated that people would enjoy sitting there for a chat or for a private phone call.

Well, they do. But users have developed another, unexpected functionality: some of the window seats seem to be a perfect spot for potted plants …


Team-building initiative between Japan and Korea

A workshop on fusion technology beyond ITER was successfully held between the Japanese and the Korean Domestic Agencies on 8-9 November at the National Fusion Research Institute in Daejeon, Korea. A first event of this kind, the workshop aimed at sharing the technology and experience of ITER procurement and also at discussing the development pathway for fusion engineering and technology beyond ITER in Japan and Korea.

More than 40 experts in fusion attended from both countries, including the head of the Korean Domestic Agency, Dr. Kijung Jung, and the head of the Japanese Domestic Agency, Dr. Eisuke Tada.

As both Domestic Agencies have entered into the full-fledged process of procurement for ITER, it was beneficial to share technical know-how, and to exchange ideas in regards to meeting the procurement schedule as well as securing core technology without any loss of productivity.

In addition, the workshop contributed to building close collaboration between the Japanese and the Korean Domestic Agencies, precisely in the spirit of the Unique ITER team for the successful implementation of all commitments for the ITER project.


From fusion to astrophysics, 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 29 October-2 November 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 15 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.


Corrective actions in place to accelerate construction

Last Wednesday, ITER Director-General Osamu Motojima called for an all-hands meeting in the Headquarters' brand-new amphitheatre in order to brief the ITER Organization staff on the outcome of the recent meetings of the projects scientific and managerial advisory committees. To this memorable event, Director-General Motojima had invited both the present and former chairmen of the Management Advisory Committee, Ranjay Sharan and Bob Iotti.

At the outset, the Director-General presented the conclusions of the 14th meeting of the project’s Management Advisory Committee (MAC) that had taken place on 29-31 October. The MAC had acknowledged the intensive work done by the ITER Organization in collaboration with the seven Domestic Agencies since the special MAC meeting held in August. Required schedule recovery actions have been taken and the collaboration between the ITER Organization and the Domestic Agencies has been intensified through the establishment of the Unique ITER Team.

„However, the MAC recognized that further and intensive efforts are necessary,” MAC Chair Ranjay Sharan explained. „The variances will have to be minimized by parallel working approaches and innovative methods. The MAC will closely monitor these approaches.”

„Yes, there are issues,” Iotti admitted, „but we are working closely together to resolve them.” Of great concern: the delays related to six super-critical items—the buildings, the vacuum vessel, the poloidal field coils, the toroidal field coils, the central solenoid conductor and the cryostat.

Two other essential issues were the focus of this 14th MAC meeting: the rules for further distribution of credits amongst the ITER Members as proposed in the „MAC-10 Guidelines,” and the proposal for a simplified assembly plan with the intention to recover some of the time slippages. „Based on the different feedback we received to this plan, the MAC suggests that the project remain focused on the normal step-by-step assembly strategy, but that it evaluate options to reduce risks and the time required for the assembly and the transport of components in order to provide more confidence in the dates for First Plasma and Deuterium-Tritium operation,” Sharan said.

As for the technical assessment, the Science and Technology Advisory Committee (STAC) commended the ITER Organization and the ITER Domestic Agencies on significant progress made, especially in the manufacturing of ITER magnets. More than 350 tons (73,000 km) of niobium-tin (Nb3Sn) strand for the toroidal field conductor have been produced so far, corresponding to approximately 75 percent of total amount needed. Also, approximately 65 tons of poloidal field conductor strand (25 percent of supply) have been produced.

The STAC noted that—with the exception of the poloidal field coils—there are currently no new major delays in the critical path due to magnets. The STAC further complimented the ITER Organization’s comprehensive report on remote handling and the good progress that has been made in developing a strategy for the installation, maintenance and potential repair of the first wall and the divertor.

„Take pride in what you have accomplished so far,” and, „Work in cooperation with others as team,” were the final comments from Bob Iotti and Ranjay Sharan respectively.



Corrective actions are now in place to accelerate ITER construction

Last Wednesday, ITER Director-General Osamu Motojima called for an all-hands meeting in the Headquarters' brand-new amphitheatre in order to brief the ITER Organization staff on the outcome of the recent meetings of the projects scientific and managerial advisory committees. To this memorable event, Director-General Motojima had invited both the present and former chairmen of the Management Advisory Committee, Ranjay Sharan and Bob Iotti.

At the outset, the Director-General presented the conclusions of the 14th meeting of the project’s Management Advisory Committee (MAC) that had taken place on 29-31 October. The MAC had acknowledged the intensive work done by the ITER Organization in collaboration with the seven Domestic Agencies since the special MAC meeting held in August. Required schedule recovery actions have been taken and the collaboration between the ITER Organization and the Domestic Agencies has been intensified through the establishment of the Unique ITER Team.

„However, the MAC recognized that further and intensive efforts are necessary,” MAC Chair Ranjay Sharan explained. „The variances will have to be minimized by parallel working approaches and innovative methods. The MAC will closely monitor these approaches.”

„Yes, there are issues,” Iotti admitted, „but we are working closely together to resolve them.” Of great concern: the delays related to six super-critical items—the buildings, the vacuum vessel, the poloidal field coils, the toroidal field coils, the central solenoid conductor and the cryostat.

Two other essential issues were the focus of this 14th MAC meeting: the rules for further distribution of credits amongst the ITER Members as proposed in the „MAC-10 Guidelines,” and the proposal for a simplified assembly plan with the intention to recover some of the time slippages. „Based on the different feedback we received to this plan, the MAC suggests that the project remain focused on the normal step-by-step assembly strategy, but that it evaluate options to reduce risks and the time required for the assembly and the transport of components in order to provide more confidence in the dates for First Plasma and Deuterium-Tritium operation,” Sharan said.

As for the technical assessment, the Science and Technology Advisory Committee (STAC) commended the ITER Organization and the ITER Domestic Agencies on significant progress made, especially in the manufacturing of ITER magnets. More than 350 tons (73,000 km) of niobium-tin (Nb3Sn) strand for the toroidal field conductor have been produced so far, corresponding to approximately 75 percent of total amount needed. Also, approximately 65 tons of poloidal field conductor strand (25 percent of supply) have been produced.

The STAC noted that—with the exception of the poloidal field coils—there are currently no new major delays in the critical path due to magnets. The STAC further complimented the ITER Organization’s comprehensive report on remote handling and the good progress that has been made in developing a strategy for the installation, maintenance and potential repair of the first wall and the divertor.

„Take pride in what you have accomplished so far,” and, „Work in cooperation with others as team,” were the final comments from Bob Iotti and Ranjay Sharan respectively.



Measuring current with light

At the Belgian Nuclear Research Center SCK•CEN in Mol, engineers and scientists are developing a system that should enable ITER to measure plasma current in a new fashion. In contrast to the present-day inductive system, the measuring principle developed by the Belgian researchers is ideal for very long shots or even steady state current measurements without the need of signal integration with time.
The measurement is based on a fully optical principle: polarized light is launched in an optical fibre. Following Faraday’s law, the light polarization plane is rotated if a magnetic field is applied along the light path. By surrounding the vacuum chamber with a fibre loop, the current of the plasma is completely enclosed. It follows from the Ampere law that the total rotation angle is directly proportional to the enclosed current.

Up until now such systems were only applied for much lower currents and in environments less harsh than that of the ITER Tokamak where radiation, temperature, vacuum, vibrations etc., make existing designs unusable.

The SCK•CEN, with a long experience in radiation-resistant fibre optics, is pursuing a sensor design based on fibres with limited sensitivity to radiation. As, due to the environment, it can’t be ruled out that the optical fibre may be compromised (i.e., a darkening of the fibre due to irradiation), the sensing fibre could be replaced by a simple intervention from outside of the cryostat: the fibre, installed in a stainless steel tube, could be replaced using a pressurized-air fibre blowing technique. If so, ITER would have the benefit of a measurement system that is easily replaceable. 

In practice, however, designing a suitable fibre blowing system in compliance with ITER geometry is a serious engineering challenge. To test the design on a real scale the SCK•CEN installed a 12-metre-high x 7-metre-wide cross-sectional drawing of ITER and positioned the stainless steel tube that will guide the fibre optics along its path around the vessel. The first tests showed that the principle is realistic and will allow for easy replacement of the fibre. The Fiber Optics Current Sensor (FOCS) principle demonstration also comprises ongoing tests at Tore Supra and Textor.
If successful, these efforts will result in the installation of three such measuring fibres around the ITER vacuum vessel. The engineering challenges are being addressed in a collaboration between SCK•CEN and the IRFM (Institut de Recherche sur la Fusion Magnétique) in Cadarache.

While plasma current measurements are a traditional diagnostic technique, the SCK•CEN researchers are investigating whether further information can be gleaned from the light signal travelling along the fibre. Detailed analysis of the return signal may result in information on the distributed magnetic field and temperature variations. Possibilities that are still under development …


ITER’s divertor remote handling system signed off

On Wednesday 31 October ITER Director-General Osamu Motojima and Jean-Marc Filhol, acting head of the European Domestic Agency’s ITER Department, signed the Procurement Agreement for the Divertor Remote Handling System (DRHS).
The DRHS provides the means for remote replacement of the ITER divertor system. The divertor handling concept relies on the use of heavy remote handling transporters known as „Cassette Movers” and dexterous, man-in-the-loop tele-manipulators. The former are required to achieve high-accuracy transport of the 8-12 ton in-vessel components from their entry point to their operational position in the vacuum vessel. The latter are required to precisely deploy a variety of mobile tools for pipe maintenance, (un)locking of the cassettes from the toroidal rails, (dis)connection of diagnostic cabling, etc.
The DRHS makes use of the remote handling transfer casks to allow safe transport of contaminated/radioactive in-vessel components to and from the Hot Cell.

Due to severe space constraints within the vacuum vessel remote handling port and the lower part of the plasma chamber, it is necessary that cassettes be handled in a cantilevered way. This generates extremely challenging design requirements on the divertor remote handling equipment, both in terms of high mechanical loads and payload position accuracy. The gaps between cassette and vacuum vessel structure may be as small as 12 mm top and bottom at certain points during the transport trajectory.

After operations, the DRHS will be decontaminated, maintained and stored in the ITER Hot Cell facility. Re-qualification/commissioning of the system will take place on full-scale mockups within the Remote Handling Test Facility (RHTF), also to be located in the Hot Cell building.

The ITER team and a number of European institutions have been working on the development of the ITER divertor maintenance concept for more than 15 years. The most challenging steps within the process have been demonstrated at full scale, first within the DTP (Divertor Test Platform) constructed in Brasimone, Italy (ITER 1998 design), and more recently within the DTP2 located in Tampere, Finland (ITER 2001 design). This long concept preparation period is now over and with the signing of the Procurement Arrangement and the engagement of an industrial supplier in the next few months, the task of establishing a fully comprehensive, industrialized set of equipment for the remote exchange of the ITER divertor begins.