Toroidal field coils: strand production passes 400 tons



„Toroidal field strand procurement is going rather well,” reports Arnaud Devred, who heads the Superconductor Systems & Auxiliaries Section at ITER. „We are on schedule.”

Manufactured by suppliers in six ITER Domestic Agencies—China, Europe, Japan, Korea, Russia and the USA—production of niobium-tin (Nb3Sn) superconducting strand for ITER’s toroidal field coils began in 2009 and has now topped 400 tons.

That’s more than 80,000 kilometres of strand—enough to go around the world twice at the Equator.

Worldwide capacity has had to ramp up significantly to meet the Project’s demand. There are eight qualified suppliers for ITER, including three that are new to the market (one in China, one in Korea and one in Russia). In 2011 and 2012, these eight suppliers, together, turned out over 100 tons annually.

„One hundred tons per annum represents a spectacular increase in the worldwide production of this multifilament wire which was estimated, before ITER production, at a maximum of 15 tons per year,” says Devred. „As you would expect, the price has come down, and this 'surge’ in production for ITER may well open up new markets.”

Eighteen toroidal field coils will be produced for ITER plus a nineteenth (a spare). That’s approximately 420 tons of strand, give or take a bit of spare material planned by each Domestic Agency. The production curve will begin to flatten in 2013 (see graph above) as contracts are brought to a close in several Domestic Agencies.

Devred estimates the market value of the toroidal field strand procurement at over EUR 200 million.

„It has been very satisfying to see this procurement unfold and to watch our international collaboration develop at every step in the process,” says Devred. „In addition to the sheer scale of this procurement, what is also remarkable is the quality control and quality assurance that we have been able to set into place.”

Four of the ITER suppliers are using a production technique called internal tin, while another four are using a bronze process. „It has been up to us to demonstrate that we can control both types of production within technical requirements,” explains Devred, „We weren’t sure of ourselves since this is the first time there has been such a large-scale production of internal tin. Test data shows that we can do it effectively.”  

Quality testing for ITER calls for statistical process control on critical parameters, systematic low-temperature measurements on strands, and regular low-temperature measurements on full-size conductors (25 percent of toroidal field conductor unit lengths are tested). This testing data is stored, like manufacturing data, in ITER’s conductor database, which is currently fed by approximately 150 users, including suppliers and Domestic Agencies. Some 350,000 individual objects are stored in this web database—created to monitor the quality assurance/quality control processes of the conductor Procurement Arrangements.

Devred credits the „early days” with setting up the processes and systems that are proving to work today for conductor procurement: before the signature of the first ITER Procurement Arrangement, the specifications for ITER conductors were written by a committee made up of worldwide experts in large conductor procurement. Very tight quality control was developed that imposes many control points at each stage of fabrication verified by the Domestic Agencies and the ITER Organization. „I believe this will be the key to our final success," says Devred. "I am confident that what is coming off of the manufacturing lines is as good as can be made.”

Read more on how strand is produced in Newsline 140.

Armed and ready to identify leaks

In constructing ITER, one of the key challenges is to ensure a leak-free machine. The US Domestic Agency has recently completed the bulk of delivery for the test equipment required to confirm the vacuum leak-tightness of components as they arrive on site and during the construction of the machine. At right,  vacuum team members are pictured with some of the leak detection tools-of-the-trade: helium spray guns and highly sensitive mass spectrometer-based detectors.

„This procurement is the very first US ITER procurement to be delivered to the ITER site,” rejoices Mike Hechler, the responsible officer within the US vacuum team. „Hence it should be celebrated as a real success. Being first we were like guinea pigs having to sort out how to deal with transport, VAT charges, customs, CE marking. It was not easy, but opens up the way for future US deliveries.”

„The basic method of leak detection is simple,” explains Liam Worth, member of the ITER vacuum team  and responsible for the test program. „You evacuate your vacuum vessel, surround it with helium gas, and then use the leak detector to look for helium leaking in—these instruments can detect in the minutest quantities.” However the size, complexity and number of the ITER vacuum systems make this a far from simple task. „We estimate that from acceptance to the final commissioning of the machine, no fewer than 94 man-years of vacuum testing will have to be performed.”

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.

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.


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.


First Russian TF Conductors shipped to Europe

Russia makes progress with the well-timed procurement of the future facility’s components to the ITER Organization. On 9 October 2012, two qualified unit lengths of Toroidal Field Conductors for the ITER magnetic system were shipped from Kurchatov Institute, in Moscow, to the customs office for their subsequent transportation to Europe. These were the copper dummy and the 100-metre qualification conductor, Russia’s first procurement of the Toroidal Field Coils Conductor.

The conductor lengths, manufactured at the Open Joint-Stock Company All-Russian R&D Project-Design and Technological Institute of Cable Industry (OJSC VNIIKP) were delivered from the National Research Centre „Kurchatov Institute”, where they had previously undergone vacuum tests involving special equipment. The next shipment of Toroidal Field Conductors is planned to take place in compliance with the schedule.

Click here to view a video of the operation.


Vacuum team cheers spearhead of US delivery

The components that were delivered on Wednesday, 20 September to Cadarache may look quite insignificant; their mass and their value represented no more than 0.001% of the Procurement Arrangement to which they belonged, but they carried a strong symbolic value.

The five pressure relief valves received by the ITER Vacuum team are the very first components delivered by the US ITER Domestic Agency. They are part of the Vacuum Auxillary Systems supply used in the acceptance and construction testing of many ITER procurements. 

„What we have here,” says ITER Vacuum Section Head Robert Pearce „is just the spearhead. It arrived on schedule and we are now waiting for the next batch of test equipment which consists of some 40 m3 of leak detectors, pumps, instruments etc. that we defined in collaboration with our US colleagues.”

From acceptance to final commissioning, no less than 94 man/years of vacuum testing will be performed on the ITER components during the Construction Phase. Holding one of the five Pressure Relief Valves in his hand, Liam Worth (Vacuum team member responsible for the test program) states that „over the next 10 years, this piece will have been used as part of more than 1,000 tests…”

The five pieces are quite simple — no spectacular technological achievement was involved in their manufacturing.  However, they demonstrate that the complex and demanding procurement process established within the ITER project has delivered: the first Design Review was held in November 2010, the Procurement Arrangement was signed in March 2011 and the „spearhead” was delivered as expected in September 2012.

The US and IO vacuum teams having kept to schedule, the Vacuum team is now looking for a place to store the bulk of equipment that will soon be delivered to ITER — „A nice problem to be faced with…” says Robert.


Vacuum Handbook recognized well beyond ITER

Everything you’ve always wanted to know about ITER „vacuum requirements” is to be found in a 44-page document (with an added 250 pages of appendixes) called the Vacuum Handbook.

The Vacuum Handbook was approved at project level in 2009 and forms part of the ITER Project Requirements and, as such, is a mandatory document to be followed by the ITER Organization, Domestic Agencies and Suppliers of vacuum equipment to the project.

„Vacuum requirements” encompass the whole set of requirements that must be observed when designing, manufacturing, installing and testing components destined to operate in a vacuum environment.

The Vacuum Handbook, whose first edition was issued in June 2009, is „both general and specific” says Liam Worth, of the ITER Vacuum Section and one of the main contributors to the document. „The Handbook contains a general background on the vacuum environment with the mandatory requirements pertaining to each of the ITER vacuum systems with the 21 appendices providing the guidelines to achieve conformity with those requirements.”

The Handbook’s requirements should be clearly stated in all Procurement Arrangement documentation and are expected to filter down the Suppliers.

Three years into its existence, the Vacuum Handbook „has been very well adopted,” says Liam. „Its value can be judged by the number of deviations from the original edition. As of today, we have granted only one…”

The value of the document is now recognized well beyond the ITER and fusion world. „Non-fusion industries have asked us for copies. And of course, we’re happy to give them.”

„The Handbook”, says Liam, „recapitulates all our knowledge and know-how into one coherent document. All in all, this amounts to about one hundred years of experience.”

At the coming 27th Symposium on Fusion Technology (SOFT) in Liège, (Belgium) two satellite meetings on the Vacuum Handbook will be held — an opportunity to „explain the rationale behind the requirements, provide some training and reach, beyond ITER and the ITER Domestic Agencies, the wider fusion community as well as industrialists.”


Electrifying months at ITER China and IO

Finalizing a Procurement Arrangement(PA)signature and, at the same time, organizing Preliminary Design Reviews (PDR) for two major systems is a very demanding task that the Chinese Domestic Agency and ITER Electrical Engineering Division performed between April and July 2012.

Assembly of documentation for the materials of the Procurement Arrangement for the Pulsed Power Electrical Network (PPEN) worth 21.9 kIUA, was finalised between January and June 2012 and signed at the last ITER Council in Washington DC.

During that same period, the Preliminary Design Reviews for two other major power supply Procurement Arrangement had to be organized, these took place last week in Beijing for the Poloidal Field AC/DC Power Converters worth 61.1 kIUA and the for Reactive Power Compensators & Harmonic Filtering System worth 16.5 kIUA.
It should be noted that for the Chinese Domestic Agency these three PAs together exceed 35% of its total in kind contribution to ITER.

Read more about the electrifying months at China Domestic Agency and ITER Electrical Engineering Division here


India signs two R&D contracts

The Indian Domestic Agency has signed two contracts for the development of the Radio Frequency (RF) sources forming part of ITER’s Ion Cyclotron Heating and Current Drive (IC H&CD) system. The contracts were signed with the American company Continental Electronics Corporation and with Thales Electron Devices, France.

The IC H&CD system is one of the major tools for achieving the plasma performances foreseen in ITER’s operation scenarios. This system is designed to provide 20 MW into the plasma, at frequencies included in the band 40 MHz to 55 MHz. ITER India is in charge of the procurement of the RF sources subsystem and the corresponding Procurement Arrangement was signed in February 2010. A total of nine RF sources will be provided: eight sources used for plasma operation, plus one spare.

For ensuring 20 MW power availability for plasma operation, 24 MW is required at the output of the transmitter at frequencies up to 65 MHz. As there is no unique amplifier chain able to meet the output power specifications, the layout consists of two parallel four-stage amplifier chains, with a combiner circuit on the output side. This configuration is used in ASDEX upgrade ICRF facilities since 1998.

Each amplifier chain is made of a wide band solid state amplifier cascaded to a three tube based tuned amplifier: a pre-driver, followed by a driver stage and a final stage. But, even in this configuration, the final stage tubes have to achieve challenging power levels.

Only two suppliers worldwide are able to reach the target. In order to identify the best and most reliable technology for building this amplifier chain, R&D contracts were signed with both companies. Results are expected by the end of next year followed by the Preliminary Design Review.