Rich Hawryluk reflects on his years at ITER

What is it like to be at the centre of ITER, the huge international fusion experiment that is under construction in France? „It’s both exciting and challenging,” said physicist Rich Hawryluk, who recently returned to the Princeton Plasma Physics Laboratory (PPPL) in the US after a two-year stint as deputy director-general for the Administration Department of ITER. „It’s exciting in the scope and scale of this effort, and challenging in bringing such a large project to completion.”

Hawryluk had many diverse responsibilities at ITER. He oversaw functions ranging from human resources to finance and budgeting to procurement and information technology. „A project this large is almost a continuous cycle of oversight and reviews,” said Hawryluk. „You’re essentially going from one major review to another every few months, and this kept us extremely busy.”

Hawryluk arrived at ITER in April 2011, a year after construction of the ITER complex began on a 180-hectare site in 2010. Contracts now are being prepared and awarded to assemble the six-storey-tall fusion facility, or Tokamak Building, that will be at the heart of the complex.

Hawryluk is no stranger to exhaustive oversight duties. He served as head of PPPL’s Tokamak Fusion Test Reactor experiment from 1991 to 1997 and as deputy director of PPPL from 1997 to 2008. He also was a member of the US delegation to the ITER Management Advisory Committee, which reports to the ITER Council. „But there’s a big difference between being an outsider on the advisory committee and dealing with day-to-day issues,” he said. „Getting immersed in and resolving the many issues that we had talked about was a major change.”

Read more on the PPPL website.

Safety regulator scrutinizes ongoing works

In the realm of nuclear safety, no detail is too small to overlook. An imprecise document, an incomplete procedure, a misplaced bolt or a slight deviation from the approved design can have serious consequences on the overall safety of the installation.

It is the duty of the ITER Organization, as nuclear operator, to ascertain that the safety requirements are understood and implemented throughout the whole chain of its suppliers and contractors, and that the procedures in application of the 1984 Quality Order are respected. And it is the mission of the French Nuclear Safety Agency ASN, in conformity with the 2007 ITER Headquarters Agreement, to verify that this duty is properly performed.

For their sixth visit to the ITER site, last Thursday 25 April, the ASN inspectors, accompanied by one expert from the French Radioprotection and Nuclear Safety Institute (IRSN), had decided to direct their scrutiny to the ongoing civil works on the ITER platform.

After a meticulous review of documents and procedures in the morning, the inspectors spent most of the afternoon onsite, focusing their attention on the B2 slab mockup (rebar arrangements and concrete formulation) and inside the Tokamak Seismic Pit, where formwork activity is progressing at a spectacular pace.

A letter summarizing the outcome of the inspection will be addressed to the ITER Director-General in the coming days and also made available to the public on the ASN web site. In nuclear safety, transparency is key.

In Korea, a week of meetings for key ITER components

An important week of meetings took place recently in Korea for the ITER vacuum vessel and thermal shield—for both of these key components industrial suppliers have been selected and manufacturing, pre-manufacturing or kick-off works have begun.

The 52nd ITER Vacuum Vessel Integrated Product Team (IPT) meeting and Domestic Agency collaboration meeting held on 8-10 April brought together over 30 experts from the ITER Organization, the European, Indian, Korean and Russian Domestic Agencies, and Korean industry (Hyundai Heavy Industry & AMW). During meetings hosted at the National Fusion Research Institute (NFRI) and at Hyundai Heavy Industry, participants shared the technology and experience of fabrication of the ITER vacuum vessel, ports and in-wall shielding, and discussed the development pathway for fabrication issues. A visit was organized to the KSTAR Tokamak at NFRI.

During a bilateral collaboration meeting held on 11 April, participants from the Korean and European Domestic Agencies—plus industrial suppliers Hyundai Heavy Industry and AMW—focused more particularly on the new technologies for fabrication of ITER vacuum vessel sectors, especially welding, nondestructive examination (NDE) and optical dimensional measurement. All parties agreed that such valuable collaboration would be continued in the future.

On Friday 12 April, the kick-off meeting for the ITER thermal shield was held—this key component will be installed between the magnets and the vacuum vessel/cryostat in order to shield the magnets from radiation. The contract for the design and fabrication of the thermal shield was awarded by the Korean Domestic Agency in February to SFA Engineering Corp, which is also the supplier selected by Korea for ITER’s assembly tooling. SFA presented the implementation plan for the procurement of the thermal shield during the meeting.

More than 20 responsible persons from the Korean Domestic Agency, SFA and the ITER Organization were present including Domestic Agency head Kijung Jung, SFA Chief Operating Officer Myung Jae Lee, and head of the ITER Vacuum Vessel Division Carlo Sborchia. Prior to the kick-off meeting, representatives from ITER and the Korean Domestic Agency agreed to collaborate closely to solve urgent design change requests related to assembly and interface issues.

„The thermal shield is one of the most critical procurement items in the ITER project. We will do our best in collaboration with the ITER Organization for its successful procurement,” stressed Kijung Jung.

Why "Plasma"?

"Plasma" is certainly the most frequently pronounced word in the fusion community. But where does the name come from? And why do we use the same term to describe an ionized gas—the „fourth state of matter”—and the yellowish liquid that holds the blood cells in suspension in a living body?

The word „plasma,” derived from the ancient Greek „to mold,” had been in use in medicine and biology for some decades when American chemist and physicist Irving Langmuir (1881-1957) began experimenting on electrical discharges in gas at the General Electric Research and Development Center in upstate New York.

In 1927, Langmuir was working with mercury vapour discharges, studying ion densities and velocity distribution in mercury arc columns. Working closely by his side, a younger physicist named Harold M. Mott-Smith was to remember in a 1971 letter he wrote to Nature how Langmuir finally suggested the word „plasma” to describe the particular distribution he was observing.

Langmuir and his team were acutely aware, as Mott-Smith wrote, that „the credit of a discovery goes not to the man who makes it, but to the man who names it,” adding: „Witness the name of our continent,” which was 'discovered’ by Columbus but christened by the lesser figure Amerigo Vespucci.

The team spent days tossing around names to best describe what they had observed. But nothing came out of these brainstorming sessions until Langmuir „pointed out that the equilibrium part of the discharge acted as a sort of substratum carrying particles of special kinds, like high-velocity electrons […] molecules and ions of gas impurities”—just in the same way blood plasma carries around red and white cells, proteins, hormones and germs.

Langmuir „proposed to call our uniform discharge a 'plasma.’ Of course, we all agreed,” writes Mott-Smith. It took some time, however, for the science community to adopt a word from the field of medicine and biology and give it a different meaning. „The scientific world of physics and chemistry looked askance at this uncouth word and were slow to accept it in their vocabulary […] Then all of a sudden, long after I had left the laboratory, to my pleased surprise, everybody started to talk about plasmas.”

Plasmas have come a long way since 1927. It is now, literally, a household name: Langmuir and his team would have been quite surprised if told that in the early years of the 21st century that plasma TVs would be much more common than the Bakelite radios of his time.

Kurchatov: the year of the three jubilees

This year has become the Year of the Jubilee for the world-famous Kurchatov Institute, which has played a key role in ensuring national security and the development of important strategic branches of Soviet and Russian science and industry since its founding in 1943 in Moscow.

In 2013, the Kurchatov celebrates the 70th anniversary of its founding, the 110th anniversary of the birth of institute founder academician Igor Kurchatov, and also the 110th anniversary of the birth of academician Anatoly Alexandrov, who became the second Kurchatov Institute director and headed it for 25 years.

The Kurchatov today possesses a unique research and technological base, performing R&D in a wide range of science and technology areas, from power engineering, convergent technologies and elementary particle physics to high technology medicine and information technologies.

The Institute’s role in the development of thermonuclear fusion research is hard to overestimate. Under the scientific guidance of Igor Golovin, the first tokamak was assembled in1955—in fact, he coined the term TOKAMAK that is now widely acknowledged by the world community.

Read more about the Kurchatov Institute here.

Why ITER is "so important for 1.3 billion Indians"

„In my country,” says acting Indian ambassador to France Indra Mani Pandey, „we are very energy deficient. This is why the success of ITER is so important for 1.3 billion Indians!”

Ambassador Pandey visited ITER last Tuesday 23 April, accompanied by his wife and one colleague. After touring the site—an experience that „helped [him] take the full measure of the challenge”—he met with the Indian staff members (29 persons presently) to discuss their experience at ITER and in France.

The Ambassador was particularly interested in learning „how the seven ITER Members collaborate on a day-to-day basis.” The way the governance of the project is organized, he felt, is a template for the future.

In dealing with the press, openness is key

On 22 and 23 April, the ITER Organization welcomed 19 science journalists from the European Union’s Science Journalist Association (EUSJA). This was the result of an initiative taken jointly by the Russian journalist Viola Egikova, vice-president of EUSJA, and ITER Communication to present ITER and the project’s underlying fusion science and technology to a group of selected science journalists.

The two-day program included a visit of the worksite and presentations by several ITER scientists and engineers on status of the project, plasma physics, the chemistry of tritium, etc. Interviews were also organized at the requests of the journalists.

As Head of Communications, I believe it is essential to work with the press and to handle their requests as swiftly as possible, as there is still a huge information gap and major communication needs relative to ITER and fusion. In my opinion, the aim is not so much the information that you deliver but the openness and the dialogue that you establish (or make visible) … and  the respect for journalistic work.

„Indeed, I was pleased to see the openness of the ITER Communication team,” said Amanda Verdonck, a free-lance Dutch journalist who participated in the EUSJA visit. „But I was really impressed by the scale of the project and the sophisticated scientific knowledge that has gone into the machine. And I will be further impressed to see all this functioning! Like your videoconference system — quite impressive to me!”

Complex logistics do not intimidate "Kevin"

Three months ago, Yanchun Qiao experienced a drastic change is his environment: moving from Shanghai (pop. 23 million) to Manosque (pop. 22,000), he left a megalopolis that never sleeps for a small town that closes down every weekday at 7:00 p.m. „I arrived on Sunday. It was very strange. It took me some time to realize that shops systematically closed on Sundays and Mondays.”

Yanchun has adapted. „You just need to buy food in advance for the weekends. This is a bit foreign for someone from China, especially someone from Shanghai, but it’s manageable.” However, closing early and remaining shuttered two days a week has its advantages: „It is a lot quieter here, and I find it’s not unpleasant at all.”

Since graduating from the Shanghai-based China Europe International Business School (a joint operation of the Chinese government and the European Commission) Yanchun has always worked for multinational  companies: he began his career at CHEP, an Australian logistics handling and equipment-pooling service company and later joined Maersk, the Denmark-based logistics giant. In both cases he was based in Shanghai, with a lot of travel worldwide.

Yanchun has come to ITER to manage the framework contracts pertaining to the transport and logistics of the ITER Organization components that Domestic Agencies will begin shipping in 2014. The complexity of the task doesn’t intimidate him. It is „quite similar” to what he did for nearly three years at Maersk. „Basically,” he says, „it’s a coordination job.”

_To_51_Tx_Yes but. „Working for the ITER project is not like working in a commercial context. At ITER, between the ITER Organization and the Domestic Agencies, it is a bit like at the United Nations. There is no direct subordination; no 'order’ that can be given … which means you need strong communication and lots of diplomacy.”

Complexity is in the nature of logistics. „There are always lots of entities involved, lots of details to deal with. In my previous jobs it was sometimes even more complicated: at Maersk, at times, I had to deal with some 50 business units. At ITER, we have only seven…”
Well, eight—if you count the French leg of the voyage. Once the components have been safely unloaded at Port de Marseille, Fos, another journey will begin—quite short as compared to the distance some of the components will have travelled by then, but complex and delicate.

The 136-kilometre Itinerary (including the crossing of the Étang de Berre by barge) that leads from Marseille-Fos harbour to the ITER site is not always direct, either geographically or administratively. As the convoys carrying the heavy exceptional components travel along the specialized ITER Itinerary, they will cross or impact dozens of administrative districts and involve several public or private entities.

Although the ITER Organization does not deal directly with the French authorities—this is the mission of Agence Iter France—it is part of Yanchun’s responsibility to keep a close eye on the ongoing processes: the improvements that are still needed on some portions of the Itinerary; the finalization of the conventions with the different entities involved, and the „big challenge” of the technical test (see box) that will be organized in September.

„Realizing the technical test in September will not impact the components delivery schedule,” says Yanchun — or should we say „Kevin,”, the nom de guerre Yanchun chose when he entered the China Europe International Business School. „I adopted the name for the convenience of communication. 'Kevin’ is a simple as possible and works in many languages and countries…”

Even in France, where the name 'Kevin’ was totally unknown and unused before the 1980s and suddenly became one the most popular given names in the following decade.

Royalties for intellectual property: a big first for ITER!

The technological demonstration of nuclear fusion as a power source may be a couple of decades away but we don’t have to wait till then to start reaping the benefits of research at ITER. Like all journeys of discovery we will meet unexpected obstacles and discover wondrous new sights, but sometimes it is the obstacles that provide the greatest reward when, by overcoming them, new techniques are born and intellectual property is generated.

For the first time, the ITER Organization has licensed intellectual property to a third party against royalties, in compliance with the ITER Agreement and its Annex on Information and Intellectual Property. ITER’s Legal Affairs contributed to the drafting of the agreement.

With support from AMEC, a UK-based company, the ITER Organization has developed software that allows a web-based program to display data on radiation calculations throughout the ITER facilities. Due to the potential applications of this software for technological areas outside of ITER and/or fusion research and development, a private company from one of the ITER Members has requested a license in order to commercially exploit this software.

Based on the principles of the ITER Agreement and its Annex on Information and Intellectual Property, the company was granted a non-exclusive, non-transferable, worldwide license to access, use and sub-license the software, software package and source code or any substantial part of it. For their part, the Domestic Agencies will be entitled to a licence by the ITER Organization, as is foreseen in the Annex on Information and Intellectual Property of the ITER Agreement.

Nuclear fusion produces radiation in the form of neutrons and gamma rays. The fusion machine is therefore designed to withstand this radiation and the buildings to shield the workers and the public. For the engineers designing the disparate components that make up the ITER machine, it is necessary to know the radiation levels that their particular system is likely to encounter.

This calculation is done by running massive computer simulations of how radiation travels through the complex geometry of pipes, walls, floors, doors and staircases of the ITER complex. Radiation maps result—something like electronic atlases showing what the radiation levels will be in every room for different operating states of ITER and during cask transfer.

How do you create an atlas accessible to anyone who needs it, easy enough to interpret, and containing all the information they need?

For this, you need a database capable of holding millions of 3D maps, a way to display them, and access through the intranet. This might sound easy enough but this was one of those occasions where unforeseen problems were encountered. The ITER Organization successfully developed a specially designed computer application to link the various tools and provide a communication protocol between them.

A "Little India" on the ITER worksite

Beginning in December 2015, the first of the ITER cryostat’s components will arrive on site. A part of India’s in-kind contribution to the project, these 54 segments are among the largest and heaviest of the whole Tokamak assembly. They will have to be  preassembled into four sections before being transported to the Assembly Building.

The pre-assembly operations will take place in a dedicated temporary workshop located on the northeast corner of the ITER worksite, slightly set back from the PF Coil Winding Facility. The workshop will be built and operated by the Indian Domestic Agency.

As stipulated in the agreement that the ITER Organization and the Indian Domestic Agency signed last Friday 19 April, this small „territory”, the size of a football field (50 x 120 m), will be made available to  the Indian Domestic Agency. Acting as building owner on this portion of the ITER worksite, the Indian Domestic-Agency will observe French labour laws and regulations.

Over the past two years and in addition to the preparation of the agreement, the ITER Building Site and Infrastructure Directorate, supported by Legal Affairs, prepared the administrative files pertaining to the environmental authorisations and building permit necessary for the construction and operation of the temporary workshop.

Work on the steel-framed workshop should begin in the coming weeks and last for 18 months. Once the building is completed, Larsen and Toubro Ltd, the Indian company that was awarded the contract for the fabrication and assembly of the ITER Cryostat in August 2012, will have some 50 people on site, and many more, locally subcontracted, once the actual assembly work begins.

Discussing experiments and aligning priorities

The 10th Integrated Operation Scenarios (IOS) International Tokamak Physics Activity (ITPA) meeting was held in the ITER Council Chamber from 15-18 April 2013. There were 30 external participants from the ITER Members and a number of representatives from the ITER Organization. The external participants include representatives from the main magnetic fusion devices and modellers from the ITER Members.

The purpose of the meeting was to discuss the experiments and modelling being carried out around the world in support of the ITER design and plasma operation as well as to align the priorities for future R&D with the latest ITER priorities. The IOS Topical Group (TG) is one of seven topical groups in the ITPA whose main role is to integrate plasma operation scenarios for burning plasma experiments, particularly for ITER, including inductive, hybrid, and steady-state scenarios. The IOS-TG also recommends physics guidelines and methodologies for the operation and design of burning plasma experiments. The ITPA topical groups all meet every six months in one of the countries of the ITER Members. This was the first time the IOS-TG met at ITER, allowing the members and experts of the IOS-TG to see first-hand the progress in ITER construction. 

Experimental and modelling results were presented from Alcator C-Mod, ASDEX-Upgrade, DIII-D, JET, JT-60U, and KSTAR of ITER-relevant plasma operational scenarios. Experimental results concentrated on inductive and hybrid scenarios; modelling of steady-state scenarios was also presented. Modelling of burning plasma and energetic particle physics were presented as well as plasma rotation in ITER and their impact on operational scenarios. The predicted plasma rotation profiles in hybrid scenarios were strongly peaked with rotation up to nearly 200 km/s, corresponding to about 4 kHz rotation in ITER in the centre. The effects of the Edge Localized Mode (ELM) coil fields on fast ion losses comparing vacuum fields and the plasma response were also shown, indicating that when the plasma response is included, the fast ion losses are acceptable even at high performance with the maximum ELM coil current.

The IOS-TG also concentrates on plasma control including experiments and modelling of profile control as well as development of the preliminary design of the ITER plasma control system (PCS). A review of the PCS conceptual design was presented as well as an action plan for how the experimental and modelling programs within the ITER Members can contribute to developing the PCS preliminary design for First Plasma and early hydrogen and helium plasma operation. Modelling of control of the entry into a burning plasma regime was also presented. A proposal was made to integrate experiments and modelling of plasma control schemes for ITER in existing experiments so that these control schemes can be developed before ITER operation to reduce run time on ITER for control scheme development. A request was made for the ITPA to provide control priorities for the ITER actuators starting with a few phases of plasma operation. 

As part of the ITPA response to the question of starting ITER with an all-tungsten divertor, the IOS-TG discussed the effect of a tungsten divertor on operational scenarios. Reports from DIII-D, ASDEX Upgrade, and C-Mod compared operation with carbon walls and metal walls. Although there were some differences, it was generally believed that ITER would be able to learn how to operate with beryllium walls and an all tungsten divertor.

Modelling of ITER and JET current ramps were also presented indicating the differences between operation with carbon walls and with the ITER-like wall on JET. Since the peak in radiation for tungsten occurs around a temperature of 1 keV, the radiation from tungsten will be peaked near the edge in ITER. There is still a question about whether or not the tungsten transport into the core can be controlled to a sufficiently small value.
Modelling of steady-state fusion plasma scenarios was also presented to understand how the present heating and current drive systems should perform as well as what upgrades might be required to meet the long-pulse goals of the ITER program. The modelling includes simulation of sawtooth control, kinetic integrated modelling, and parameter scaling from existing experiments to ITER steady-state regimes. An update was also given on the latest proposed changes to the steering of the electron cyclotron heating and current drive system that was followed by extensive discussion.

In summary, the meeting provided valuable information on recent experiments and modelling of ITER plasma operation scenarios. Actions for the ITPA members and experts to help define the preliminary design of the ITER plasma control system were agreed upon. Continued experiments and modelling to demonstrate ITER operational scenarios for the inductive, hybrid, and steady-state scenarios were presented. A special report on the impact of an all-tungsten divertor on ITER operational scenarios was also discussed at length. 

Construction of Cryostat Workshop to begin

There’s already one facility on site for the fabrication of ITER components that are too large for transport and there’s soon to be another. Ground breaking begins in May for a temporary workshop where the four main sections of the cryostat will be assembled from 54 smaller segments manufactured by India.

Like the largest poloidal field coils, the size and weight of the main cryostat segments makes travel along the ITER Itinerary impossible. The cryostat base section—1250 tons—is the single largest load of ITER Tokamak assembly; the other three cryostat sections (lower cylinder, upper cylinder and top lid) weigh in the range of 600-800 tons each.

Within the on-site Cryostat Workshop, assembly activities will take place on two huge steel platforms built to support the weight of the components, jigs and fixtures.

„The 30 x 30 metre assembly platforms will also act as transporters,” explains Bharat Doshi, Leader of the Cryostat Section. „The Cryostat Workshop will be linked by rail to the Assembly cleaning facility and building. Once completed, the cryostat sections can be moved on their assembly platforms by rails/rollers to the Assembly cleaning facility and from there transported to the Tokamak Pit by main bridge crane.”

Planned along the fence on the northeast corner of the ITER platform, the football field-size (50 x 100 m) Cryostat Workshop will be approximately 100 metres from the Assembly Building. It will be equipped with equipment for machining, welding and testing, and a large „goliath” crane capable of travelling the facility’s full length. „Assembling the four main sections, each 30 metres in diameter, will require several kilometres of joint welding in total,” specifies Bharat.

As a high vacuum component, the cryostat is subject to strict quality requirements. Two types of testing will be carried out in the Workshop: an examination of each weld through non-destructive means (ultrasonics or radiography) and the vacuum leak testing of each joint (helium mass spectrometer leak detection). Dimensions and tolerance control will be achieved using sophisticated alignment and metrology equipment. Approximately 50 people are expected to manage the machining, alignment, welding and testing operations during assembly of the cryostat segments.

„The ITER cryostat will have the privilege of beginning and ending the assembly of the ITER Tokamak,” says Bharat. „The base section of the cryostat will be the first large component installed in the Tokamak Pit and the top lid of the cryostat will be the last large component, set into place after the installation of the vacuum vessel, magnets, thermal shielding and central solenoid.”

As soon as the Tokamak and Assembly buildings (and their heavy-lift crane) are available, the cryostat base must be ready … and the lower cryostat cylinder soon after that. The Indian Domestic Agency is procuring two transporter platforms so that work can be carried out in the Cryostat Workshop on the two sections simultaneously. A gap of about two years will then follow before the upper cylinder and top lid can be assembled in the pit.

The contract for the design, fabrication and assembly of the cryostat was awarded in August 2012 by the Indian Domestic Agency to Larsen & Toubro Ltd—this contract also includes the set-up of the Cryostat Workshop, workshop assembly activities, and in-pit assembly (integration of cryostat main sections, welding, etc.). In the autumn, Larsen & Toubro awarded the construction of the Workshop to the French company SPIE Batignolles TPCI (part of the consortium that built the ITER Poloidal Field Coils Winding Facility).

Work on the steel-framed structure is scheduled to last 18 months.

Commr. Busquin was key in Europe’s bid for ITER

ITER owes a lot to a few individuals who, at decisive moments in the project’s history, made decisions that changed the course of events.

Philippe Busquin is one of them. In 2001, as European Commissioner for Energy (1999-2004), he played a key role in pressing the Commission to commit itself to actually realizing ITER.

„I took the responsibility to launch ITER,” he recalls. „At the time, the European effort to develop fusion was quite diluted amongst several associations. ITER was still a paper project and I felt it was high time to get on to the experimental phase.”

2001 was a defining year for ITER. A new design for the Fusion Energy Advanced Reactor („ITER-FEAT”) had been approved by the ITER Council; Canada had proposed to host the installation; local governments in Provence were mobilizing to promote the Cadarache site… For Busquin, the time was ripe to take action.

„As a nuclear physicist, I could measure what was at stake with fusion; as a politician, I knew Europe had to be daring. And I was optimistic…”

Two years later, in 2003, Europe had two sites to offer to ITER—one in Vandellòs, Spain; one in Cadarache, France. Busquin considered at the time that this „double offer” was proof of Europe’s determination to host the project.

As he stood above the Tokamak Seismic Pit, one decade later, the former European Commissioner felt profound satisfaction and a sense of pride.

„I was standing close to where we are now, with French Research Minister Claudie Haigneré and all the people who worked so hard to make ITER happen here—of course the landscape was quite different but I can still recognize the place.”

Philippe Busquin, now retired from public affairs (but still active in promoting collaboration between industry and the academic world) took some time from a vacation with his wife and son to meet ITER Director-General Osamu Motojima and visit the ITER site last week.

As for the future of ITER, he is as optimistic in 2013 as he was in 2001. „With ITER we are working at the limits of about every available technology,” he says. „We cannot begin to imagine the benefits of such a venture. But the project is also a first in terms of international governance and management. In this respect also, what we are learning will have huge consequences for the future.”

Green light for ITER’s blanket design

After three days and 29 presentations, a comprehensive design review with probably the largest participation in the history of the ITER project was completed last week. More than 80 experts from the ITER Organization, Domestic Agencies and industry attended the Final Design Review of the ITER blanket system.

„The development and validation of the final design of the blanket system is a major achievement on our way to deuterium-tritium operation—the main goal of the ITER project,” Blanket Integrated Product Team Leader (BIPT) and Section Leader Rene Raffray concluded at the end of the meeting, obviously relieved at the success of this tremendous endeavour. „We are looking at a first-of-a-kind fusion blanket which will operate in a first-of-a-kind fusion experimental reactor.”

The ITER blanket system provides the physical boundary for the plasma and contributes to the thermal and nuclear shielding of the vacuum vessel and the external machine components such as the superconducting magnets operating in the range of 4 Kelvin (-269°C). Directly facing the ultra-hot plasma and having to cope with large electromagnetic forces, while interacting with major systems and other components, the blanket is arguably the most critical and technically challenging component in ITER.

The blanket consists of 440 individual modules covering a surface of 600 m2, with more than 180 design variants depending on the segments’ position inside the vacuum vessel and their functionality. Each module consists of a shield block and first wall, together measuring 1 x 1.5 metres and weighing up to 4.5 tons—dimensions  that not only demand sophisticated remote handling in view of maintenance requirements during deuterium-tritium operation, but also an approach to attaching the modules which is far from trivial when considering the enormous electromagnetic forces. 

The first wall is made out of shaped „fingers.” These fingers are individually attached to a poloidal beam, the structural backbone of each first wall panel through which the cooling water will be distributed. Depending on their position inside the vacuum vessel, these panels are subject to different heat fluxes. Two different kinds of panels have been developed: a normal heat flux panel designed for heat fluxes of up to 2 MW/m2 and an enhanced heat flux panel designed for heat fluxes of up to 4.7 MW/m2.

The enhanced heat flux panels are located in areas of the vacuum vessel with greater plasma-wall interaction and they make use of the hyper-vapotron technology which is similar to that used for the divertor dome elements. All panels are designed for up to 15,000 full power cycles and are planned to be replaced at least once during ITER’s lifetime. A sophisticated R&D program is currently under way in Japan for the development of remote handling tools to dismantle and precisely re-position the panels.  

Due to the high heat deposition expected during plasma operation—the blanket is designed to take a maximum thermal load of 736 MW—ITER will be the first fusion device with an actively cooled blanket. The cooling water is fed to and from the shield blocks through manifolds and branch pipes. Furthermore, the modules have to provide passage for the multiple plasma diagnostic technologies, for the viewing systems, and for the plasma heating systems.

Because of its low plasma-contamination properties, beryllium has been chosen as the element to cover the first wall. Other materials used for the blanket system are CuCrZr for the heat sink, ITER-grade steel 316L(N)-IG for the  steel structure, Inconel 718 for the bolts and cartridges, an aluminium-bronze alloy for the pads that will buffer the electromechanical loads acting on the segments, and alumina for the insulating layer. 

The procurement of the 440 shield blocks is equally shared between China and Korea. The first wall panels will be manufactured by Europe (50%), Russia (40%) and China (10%). Russia will, in addition, provide the flexible supports, the key pads and the electrical straps. The assembly of the blanket is scheduled for the second assembly phase of the ITER machine starting in May 2021 and lasting until August 2022. The work will be performed with the help of two in-vessel transporters working in parallel.

In assessing the work presented at the Final Design Review, Andre Grosman, deputy head of Magnetic Fusion Research Institute at CEA and chair of the review panel, enthusiastically commended the BIPT for its achievements since the Preliminary Design Review in December 2011 which were „beyond the expectation of the panel.” He added: „We have singled out the continuity and benefit of the work done by the ITER Organization and the Domestic Agencies within the BIPT framework with a sharing of risk and information among all stakeholders.”

The panel nevertheless pointed out some remaining issues, including a few challenging issues that need to be addressed at the project level. But thanks to the excellent quality of work performed by the BIPT, the ITER blanket design can today be called „approved.” The BIPT can now turn its focus to addressing the feedback received at the Final Design Review, applying the final touches to the design, and preparing for the Procurement Arrangements, where fabrication is handed over to the Domestic Agencies, starting at the end of 2013.

Where rebar meet

In order to have a hands-on experience of the difficulties that could be encountered in the creation of the B2 slab—the 1.5-metre-thick reinforced concrete 'floor’ that will support the Tokamak Complex—a 150-m2, 1:1 scale mockup is currently under construction on the ITER platform.

Different rebar arrangements, presenting specific challenges, are being reproduced by the mockup. The rebar in this picture reproduces the interface zone between orthoradial (a grid of circles surrounding a point and lines starting from that point) and orthogonal (right-angled) arrangements.

In the B2 slab, one fourth of the total rebar is arranged in an orthoradial manner (the central area of the Tokamak Complex); the rest is orthogonal. How these areas interface is critical to the B2 slab’s robustness.

Fusion draws on Japanese traditions

The Japanese people have a long history of creating ceramics of great beauty and elegance. Now they are putting their skills towards the search for materials for future fusion plants — in this case not crafting elegant forms, but elegant solutions: ceramics are nearly impervious to tritium.

In a colloquium delivered at JET last week, Assistant Professor Takumi Chikada from the University of Tokyo outlined promising progress in research into the ceramic coating, erbium oxide, which may prove to be a vital coating for use in tritium-carrying pipework. „Without solving this problem it will be impossible to operate a fusion reactor,” he stated.

Because of its very small size, tritium tends to permeate through materials readily — an undesirable characteristic in a tritium processing plant, where tritium would be exposed to a large surface area as it passes through cooling, ducting and processing pipework.
Assistant Professor Chikada’s results showed that a layer of erbium oxide only tens of microns thick on a steel surface could reduce permeation of tritium by 100 000 times.

Erbium oxide was originally chosen as an insulation coating because it has a high thermodynamic stability and is resistant to liquid lithium-lead — a proposed blanket material for fusion plants, which is corrosive to many materials.

Read more on the EFDA website.

A GÉANT on the fusion data highway

Since the ninth of April, GÉANT, the world’s leading high-speed research and education network managed and operated by DANTE in Cambridge, UK, has been providing data links to the International Fusion Energy Research Centre (IFERC) in Rokkasho, Japan.

IFERC hosts the Helios supercomputer, a system with a compute power exceeding 1 PFlops attached to a storage capacity of 50 PB. The Helios supercomputer is provided and operated by the French Alternative Energies and Atomic Energy Commission (CEA) and is a European Domestic Agency resource.

GÉANT is supplying a 10 Gbps (10 Gigabits per second) link to connect Helios with scientists involved in ITER and DEMO, the demonstration fusion reactor considered as the follow-up to ITER.

It is hoped that, after the first fusion plasmas of ITER planned for 2020 and beyond, DEMO, an industrial demonstration fusion reactor, will lead to full-scale fusion energy reaching the commercial market in the second half of this century.

Read more on the European Domestic Agency website.

"Human factors" at the heart of Control Room design

A control room today, whether for a railway system, space mission or power plant, is more than just seats, desks and computer screens. It is a highly organized working environment where nothing is left to chance.

Over the past decades, a branch of science and engineering has developed that aims at optimizing the relationship between the human operators and the systems they operate. „Human factors” is a multidisciplinary approach that incorporates contributions from ergonomics, psychology, ethnography, industrial design, and biomechanics.

It is at the heart of how ITER approaches the design of its Control Room. But what is standard procedure in most industries takes on a special dimension here: the specificity of the ITER experimental machine and operation program generates some unique challenges.

„Due to the complexity of the machine and to the number of people involved both on location and through remote participation, the ITER Control Room is larger than usual,” explains ITER head of the Assembly & Operation Division Ken Blackler. „Where JET or Tore Supra have an average of 20 operators in their respective Control Rooms, we will have 60 to 80 operators, engineers and researchers.”

The size of the room and the number of operators means that special attention must be paid to noise dampening, seating design, and the floor plan. „The operation of a fusion research device is very collaborative, especially on an international project such as ITER,” adds Ken. „You have to anticipate how people will group, and decide on the optimal distance between desks: not too close to prevent a feeling of crammed place … not too far to facilitate communication.”

As in any Control Room, computer screens will display all the information needed to drive the machine. But in what way? „Beyond the raw data, we need to give operators a 'vision’ of the information, using real-time 3D images for instance to provide a better sense of understanding. That’s what we did in JET and that’s what we will optimize in ITER.”

Providing a physical, realistic perception of the machine is also essential. Operators in the ITER Control Room will see in real time—in both the visible and infrared spectrum—what is happening inside the Tokamak.

The ITER Control Room will occupy a large area under 7-metre ceilings, creating a „strong sense of space.” Interior lighting will follow the pattern of natural light to provide a "sense of time"—important in a facility that will operate 24 hours a day, seven days a week. Windows will also let in a bit of natural light or allow a vision of the night sky. And an outside balcony, adjacent to the small restaurant area, will allow for a breath of fresh air from time to time.

The multicultural nature of the project will generate other challenges—colour codes and symbols are not as universal as we may think. „What does a red light signify?” asks Ken. „Does it mean something is working or stopped? Safe or dangerous? This is something we have to clearly establish.”

_To_48_Tx_At this stage of the project, it is necessary to producing a preliminary design of the ITER Control Room in order to finalize the design of the Control Building, the two-storey structure that will host the Control Room, the CODAC computer centre and several meeting rooms and offices.

To this end, the ITER Organization has commissioned the UK human factors consultancy specialist CCD which has completed more than 350 control room designs over the past 30 years, among them the London Air Traffic Control Centre, the Easy-Jet Operations Room, and control rooms for the Hong Kong Police and CERN’s Large Hadron Collider.

Final design will be completed in a few years’ time, just before procurements are launched. The layout will be flexible as possible for it may need to be adapted in the course of ITER commissioning and operation.

In less than eight years, by crossing the glass-walled walkway leading to the operational centre of ITER, one will enter a world scientifically designed for the efficient, productive and safe interaction between man and machine.

Click here to view a video animation of the ITER Control Room.