Foundations
The basemat for the Tokamak Complex—the 1.5 metre-thick B2 slab—will sit directly on top of the Seismic Pit's 493 columns and pads. On 27 February 2013, the Central Integration & Engineering Directorate completed the challenging mission of closing B2 slab design and obtaining model approval in a meeting held with the European Domestic Agency and the Architect Engineer ENGAGE. Work began immediately on B2 propping and formwork activities in the Seismic Pit.
The completion of the heavily reinforced "B2" concrete basemat in August 2014 was the last in a series of steps undertaken over four years to create the ground support structure and foundations for the ITER Tokamak.
From August 2010 to August 2014, workers excavated the 17-metre-deep, 90 x 130 metre Tokamak Complex Seismic Pit, created a ground-level basemat and retaining walls, installed 493 seismic columns and pads, and poured the B2 basemat slab (the "floor" of the Tokamak Complex).
On the level surface of the Seismic Pit basemat, 493 columns topped with anti-seismic bearings, made of alternate layers of metal and rubber, were put in place at regular intervals. With a capacity for lateral movement of 10 cm, these 20-cm-thick bearings are capable of filtering and absorbing the accelerations linked to earthquake-induced ground motion.
The Tokamak Complex B2 slab is a heavily reinforced basemat (9,300 m², 1.5 metre thick) that will support the Tokamak Complex and its 440,000 tonnes of buildings, machinery and equipment. The last segment—a perfectly circular, central plot that will support the ITER machine—was poured in August 2014.
The completion of the B2 slab marked the beginning of the second phase of ITER construction: the start of civil construction works on the seven-storey Tokamak Complex. Eighty metres wide, 120 metres long and 80 metres tall (60 metres above ground level), the Tokamak Complex houses the Tokamak, Diagnostics and Tritium buildings. For more information on Tokamak Complex construction, see this page.
Foundation Facts
Tokamak Complex ground support structure:
- Construction: 18 months (completed April 2012)
- Amount of steel reinforcement: 6,000 tonnes
- Concrete required: 25,000 m³ (basemat and walls)
- Thickness of Seismic Pit basemat: 1.5 metres
- Thickness of retaining walls: from 1.5 metres (bottom) to 0.5 metres (top)
- Number of seismic pads supporting the Tokamak Complex: 493
Tokamak Complex basemat (B2):
- Construction: 9 months (December 2013-August 2014)
- Amount of steel reinforcement: 3,600 tonnes
- Concrete required: 14,000 m³
- Thickness of Tokamak Complex basemat: 1.5 metres
Photo Gallery
The "basement" of the Tokamak Complex
2014-10-28 - Underneath the B2 basemat slab are the 493 pillars and anti-seismic bearings that will support the weight of the Tokamak Complex. With 1.9 metres between the lower concrete slab and the upper slab, there's plenty of room to move around.
Mission accomplished
2014-09-18 - The end of B2 slab works is celebrated with a traditional méchoui (roast lamb on a spit) on 18 September.
Lowering the cranes
2014-09-08 - Now that the Tokamak Complex foundations are in place, the four corner cranes used by the GTM consortium are coming down. They will be replaced by five taller cranes (including one that will work from the centre of the basemat) for wall construction.
The completed slab
2014-09-02 - The B2 slab—14,000 m³ of concrete, 3,600 tonnes of reinforcement and 2,500 embedded plates—stands ready to receive the first walls of the Tokamak Complex.
The B2 slab is "topped out"
2014-09-02 - An olive branch is left by workers in the centre of the completed Tokamak Complex basemat slab (B2 slab). Originating in Eastern Europe, this construction tradition called "topping out" symbolizes the end of works.
The floor is finished
2014-08-27 - 493 anti-seismic columns and pads are sandwiched between the B2 slab, completed today, and the lower basemat installed on the floor of the Tokamak Pit. The B2 slab will be the first basement level of the Diagnostic, Tokamak and Tritium buildings.
A landmark day for ITER
2014-08-27 - The completion of the 9,300 m² B2 slab on 27 August concludes four years of work (2010-2014) to create a ground support structure for the Tokamak Complex.
Just the right formulation
2014-08-27 - Consistency and spreadability are important to ensuring the homogenous distribution of the concrete. These parameters are tested as the concrete leaves the on-site batching plant, before it gets loaded into the mixer trucks. Photo: F4E
Standing on the slab
2014-08-27 - Works were carried out by the F4E construction consortium led by GTM Sud from France. GTM was also in charge of the excavation of the Tokamak Complex Seismic Pit (August 2010-April 2011) and the construction of the lower level basemat and retaining walls (April 2011-April 2012).
A lot of material
2014-08-27 - The last pour—for the circular central segment of the basemat—required 865 m³ of concrete. In total, the 1.5-metre-thick B2 slab contains 3,600 tonnes of rebar and 14,000 m³ of concrete.
A series of important operations
2014-08-27 - The concrete is poured (far left), vibrated to eliminate air pockets (middle left) and smoothed for a perfect finish (far right). Photo: F4E
It's done!
2014-08-27 - The B2 slab, which will support some 400,000 tonnes of building and equipment (including the 23,000-tonne ITER Tokamak), is now in place.
Any day now
2014-08-26 - On 26 August, workers carry out the final activities on the central segment to prepare for concrete pouring, which is imminent.
Northern segments completed
2014-08-21 - Looking toward the excavated area for the future Hot Cell, and also towards ITER Headquarters, the concrete foundation of the Tritium Building is now flush with that of its neighbour, the Tokamak Building.
The last pour will be circular
2014-08-21 - In terms of volume, it's slightly less than the surrounding segments. The last pour of the B2 basemat slab will require 865 m³ of concrete.
Preparing for the last pour
2014-08-21 - Workers are busy preparing the last pour of the Tokamak Complex B2 slab.
Southern segments completed
2014-08-21 - A smooth concrete surface is now in place in the southern part of the Tokamak Pit, where the foundations of the Diagnostic Building abut those of the Tokamak Building.
Bull's eye
2014-08-21 - In the very centre, is a large circular embedded plate that will be used as a base for securing machinery or equipment.
Last measurements before pouring
2014-08-09 - In the centre of the basemat, a large steel ring (topped with a blue steel structure designed to prevent deformation) will be deeply anchored in the concrete. Its purpose? To provide a base for the huge inner support column that will stabilize the vacuum vessel sectors during the first stages of machine assembly.
Taking advantage of a clear night
2014-08-05 - On three occasions in July and in August, the pouring operations took place at night from 10:30 p.m. to noon the next day. Photo: F4E
Rapid progress on the B2 slab
2014-08-05 - The thirteenth B2 slab segment out of fifteen) is poured on 5 August. Photo: F4E
All through the night
2014-08-05 - For three weeks this summer, contractors had the authorization to carry out night pours. On a summer night, the temperature is ideal for concrete pouring ... Photo: F4E
Closing in on the centre
2014-07-29 - On 29 July, the fourth of nine central segments is poured. To create the 9,600 square-metre Tokamak Complex basemat slab, workers will have used 14,000 cubic metres of concrete and 3,600 tonnes of rebar.
A fish-eye view of the Tokamak Pit
2014-07-29 - Pouring continues for the central segments of the Tokamak Complex basemat on 29 July.
Starting in one corner
2014-07-10 - A 627-square-metre segment, adjacent to the Diagnostics Building slab on the north side of Seismic Pit, was the first of nine plots to be poured on 10 July.
Work begins on the central area
2014-07-10 - Pouring begins on 10 July 2014 on the central area of the B2 slab--which will support the machine--following the green light from the French Nuclear Safety Authority (ASN). Nine segments make up the central part of the slab.
2014-07-07 - From this angle the thickness of the B2 basemat slab (1.5 metres) is clearly visible.
Nine segments to go
2014-07-01 - Concrete pouring in the central area will be carried out from July to September 2014.
Tritium slab completed
2014-07-01 - The third and final pour for the Tritium Building basemat was carried out on 26 June. Now only the nine central segments remain to complete the Tokamak Complex basemat.
Next, the walls will rise
2014-07-01 - Rebar is already in place for certain of the Tokamak Complex's walls. Building construction begins in 2014.
A solid foundation for the Tokamak Complex
2014-07-01 - When completed, the 9,600 m² Tokamak Complex basemat will have incorporated some 14,000 tonnes of concrete and 3,600 tonnes of steel.
Segment #5 is poured in June
2014-06-19 - On 19 June, workers pour the second Tritium Building basemat segment. There are ten segments to go to complete the Tokamak Complex slab
Pouring on a sunny day
2014-06-19 - 1,155 cubic metres of specially formulated concrete went into the second segment of the Tritium Building basemat slab. Pouring conditions on 19 June were ideal.
Strong progress in the Seismic Pit
2014-05-27 - Approximately 100 people are currently working in the Seismic Pit, laying rebar, securing embedded plates, and preparing for the next two segment pours for the Tritium Building.
4,000 tons of iron and a mockup
2014-05-21 - Iron elements for the B2 foundation slab are stored near a full-scale mockup on the platform that reproduces the most complex areas of reinforced concrete. Once poured, the concrete will be closely examined to make sure that it is uniformly distributed throughout the mockup's dense metal skeleton.
Under the future machine
2014-05-21 - The ITER machine (vacuum vessel, magnets plus cryostat) will measure 30 metres in width and as many in height. It will weigh an estimated 23,000 tonnes.
Thousands of embedded plates
2014-05-20 - Embedded plates are set into position before any concrete pouring activity can be carried out; once the buildings are in place, equipment and machinery will be welded to these plates.
Playing heavy metal
2014-04-29 - Some say it looks like the largest record player in the world! Some 400,000 tonnes of building, machinery and equipment will be contained in this large concrete box called the Tokamak Complex Seismic Pit.
Inspectors in the heart of the web
2014-04-24 - On Thursday, 24 April, inspectors from the French Nuclear Safety Authority (ASN) carry out an inspection of ongoing reinforcement work on the Tokamak Complex basemat slab. They are pictured inspecting the very centre of the rebar web that will support the future Tokamak Building.
The most complex part of the puzzle
2014-04-21 - Some 4,000 metric tons of steel rebar will reinforce the Tokamak Complex basemat. The central part of the basemat will be poured in nine segments. Photo: F4E
Planning for pouring
2014-04-21 - In the dense rebar under the Tokamak Building, space is left every few metres for the vibrating tools that will ensure that the wet concrete reaches every nook and cranny. Photo: F4E
Eleven segments to a completed basemat
2014-04-10 - The Tokamak Complex basemat will be poured in fifteen segments. Pour days are scheduled this month and next to complete the Tritium Building basemat (at the far end of the Seismic Pit); rebar work in the centre should be finished in July.
The eye of the torus
2014-03-21 - In the central area of the Tokamak Pit, a combination of orthogonal and orthodradial rebar create a particularly tight and complex pattern. As work advances, metal "chairs" are installed to separate the first layers of rebar from the top layers.
Let's switch sides!
2014-03-19 - Concrete is poured on 19 March in the northeast corner of the Tokamak Pit. This fourth segment (638 square metres, 957 cubic metres of concrete) is the first part of the Tritium Building basemat to be poured.
Progress on the basemat
2014-03-19 - The fourth pour day for the Tokamak Complex basemat was carried out on 19 March. Pouring has begun for the Tritium Building basemat on the north end of the Pit.
Diagnostics Building basemat
2014-03-04 - The completed basemat for the Diagnostics Building now stands 1.5 metres over the rebar of the central section. By next autumn, the floor of the Tokamak Complex will be in place.
Spot in the middle
2014-03-04 - In the very centre of the Seismic Pit stands the last viewable seismic pad. The Tokamak Complex will rest on 493 such pads, part of the measures that will protect the scientific infrastructure in the case of ground motion.
A 1:1-scale mockup for Tokamak basemat reinforcement
2014-03-04 - This mockup of Tokamak basemat reinforcement is being prepared for concrete. Because of the complexity and density of rebar in the region under the Tokamak, concrete pouring is a complex operation that will be tested first here.
Where orthoradial and orthogonal meet
2014-03-04 - Under the future Tokamak, crisscrossed layers of orthoradial (circular) and orthogonal (right-angled) rebar form a pleasing geometric pattern.
Maintaining a clean surface
2014-03-04 - On the completed Diagnostics Building basemat, pressurized air is used to keep the surface clean. The cages in the picture mark out the pillars that will be poured to support the second floor of the building.
The Pit in February
2014-02-27 - In February, work on the rebar arrangement in the centre of the Tokamak Pit--that will support the machine--resumes. Sixteen layers of orthoradial (circular) and orthogonal (right-angled) rebar will be integrated into the 1.5-metre-thick basemat.
Getting ready to pour the foundations of the Tritium Building
2014-02-26 - The next area of the B2 slab to be poured is on the north side of the Seismic Pit under the Tritium Building. Just like for the Diagnostics Building, pouring will take place in three stages (beginning in March).
A sea of iron
2014-02-19 - Reinforcement works should continue in the Tokamak Pit through July. Some 4,000 tonnes of iron rebar will be part of the Tokamak Complex slab. Photo: F4E
Last pour for the Diagnostics Building
2014-02-15 - The final segment poured on the south side of the Tokamak Pit measures 600 square metres (900 cubic metres of concrete). Photo: F4E
Standing on the rebar
2014-02-15 - On the Diagnostic Building side of the Tokamak Pit, work to prepare for a concrete pour is underway. The squares at ground level are the embedded plates that will be used to fix equipment and machinery in the completed structure. Photo: F4E
A full day of work
2014-02-15 - As concrete is poured in February for the Diagnostics Building basemat, workers use equipment to ensure that the material settles uniformly, without air pockets. Photo: F4E
Looking west
2014-02-15 - The tall crane allows us to imagine the height of the future Tokamak Complex: 60 metres. Photo: F4E
Where the action is happening
2014-02-13 - A wide angle lens captures nearly the entire Tokamak Pit. Photo: F4E
Pouring completed for Diagnostics Building basemat
2014-02-13 - On Thursday 13 February, the third and final segment of the Diagnostics Building basemat was successfully poured. Concrete pouring activities will continue in March on the opposite end of the Seismic Pit, under the future Tritium Building. Photo: ENGAGE
Looking north
2014-02-12 - Three distinct work areas are visible in February in the 90 x 130 metre Seismic Pit: in the foreground, the beginning of concrete works for the Diagnostic Building slab; at the far end, ongoing reinforcement works for the Tritium Building slab; and in the centre, the positioning of rebar layers (16 in all) under the future Tokamak Building.
Going up!
2014-02-03 - This vertical rebar is the first set into place for the future walls of the Tokamak Complex. Photo: F4E
Careful calculations
2014-02-03 - Each iron bar, weighing nearly 100 kilos, is carefully laid and affixed.
Reinforcement work resumes
2014-01-28 - In the centre of the Seismic Pit, under the future Tokamak, work resumed on the complex pattern of steel reinforcement bars.
Early morning fog
2014-01-22 - The raised reinforcement along the Seismic Pit wall that we can just distinguish to the right will on day support the load of the Diagnostics Building. A third and final pour will complete this part of the basemat.
Second segment of basemat completed
2014-01-22 - On 22 January 2014, the second of fifteen Tokamak Complex basemat segments was poured over a ten-hour shift starting at 6:00 a.m. All work should be completed in July.
Pouring on a cold day
2014-01-22 - The concrete is still warm when it arrives at its destination, having lost only a couple of degrees Celsius during transport. The concrete is made with heated water and gravel in the on-site batching plant and leaves the facility at 14-17 °C.
And on the left ...
2014-01-15 - It's easy to distinguish the reinforcement going on for the Tritium Building, which will occupy the left side of the Seismic Pit, from the reinforcement that will support the weight of the ITER Tokamak and Tokamak Building (centre).
One down, fourteen to go
2013-12-17 - The first concrete pour took place under the future Diagnostics Building, part of the three-building Tokamak Complex. Fifteen pour days in all will be necessary to complete the B2 slab; then, the walls will begin to rise.
First B2 segment in place
2013-12-17 - Under the blue drying tents, the first 21 x 26 metre segment is in place for the Tokamak Complex basemat slab (the B2 slab). The next pour is scheduled for early 2014.
12-hour pour day
2013-12-11 - The first segment is a 21 x 26 m area under the future Diagnostics Building. Over the 12-hour day, a volume of 800 m3 of concrete is poured. Photo: F4E
On-site production of concrete
2013-12-11 - Two pumps worked in unison to deliver the special-grade concrete, qualified for the specificities of the ITER facility through extensive testing and produced in an on-site batching plant.
ITER-grade concrete
2013-12-11 - The concrete formulation is the same as that used for the seismic columns of the Seismic Pit, tested over twenty times for its properties of stability, water permeability and gas confinement.
Continuous flow
2013-12-11 - The pumps are fed in a continuous flow by concrete trucks that drive back and forth from the on-site batching plant. Photo: F4E
Pouring begins
2013-12-11 - In the northwest corner of the Seismic Pit, under the future Diagnostics Building, the first concrete pouring for the B2 slab got under way at 6:24 a.m. on 11 December 2013.
An early day for some
2013-12-11 - The first segment of the B2 basemat was poured in approximately 12 hours by two shifts of workers. The first team of 20 began the day at 4:00 a.m. to prepare the work site.
All in a row
2013-11-29 - Some 750 of the 2,600 planned embedded plates for the Tokamak Complex basemat have been installed. These plates provide robust anchorage for equipment and tooling.
Small coffee tables with supernumerary legs?
2013-10-08 - No. Embedded plates waiting for installation. These plates will provide extremely robust anchorage for the devices that need to be attached to the walls (or floors, or ceilings) of the Tokamak Complex and that can weigh several tons.
Installation of embedded plates
2013-10-08 - Once the foundation is poured, these embedded plates will be solid support for the elements that will be welded to their surface.
Seen from the crane
2013-10-02 - To the left of the future Tokamak Building: Tritium. To the right: Diagnostics. Concrete pouring for the B2 basemat slab will begin in these areas. Photo: F4E
Positioned just so
2013-10-01 - The encounter of radial reinforcement and linear reinforcement creates a striking pattern on the floor of the Tokamak Complex.
2013-10-01 - Metal "chairs" are positioned on the bottom layer of crisscrossed rebar. Steel reinforcement will be built up to 1.5 metres before foundation pouring begins.
The complexity of the Tokamak Complex basemat
2013-10-01 - Finger-like, the tops of the seismic pads protrude through the pattern of rebar.
Space to walk all around
2013-10-01 - Between the Tokamak Complex and the retaining walls of the Seismic Pit there will be a gap of about 2 metres ... space for lateral movement in case of ground motion.
Reinforcement underway
2013-10-01 - When reinforcement work ends, 4,000 tonnes of steel rebar will be in place at the bottom of the Tokamak Seismic Pit—part of the B2 foundation slab that will support the Diagnostic, Tokamak and Tritium buildings.
In so many rows
2013-09-26 - Sixteen of the sixty thousand embedded plates will be integrated into the Tokamak Complex basemat (see the squares being settled into place on the Diagnostics end of the Seismic Pit).
Heads up!
2013-09-26 - In the floors, walls and ceilings of the Tokamak Complex there will be roughly 60,000 embedded plates to provide extremely robust anchorage, capable of supporting loads of up to ~90 metric tons in pure traction. Photo: F4E
Machine + cryostat + bioshield
2013-09-18 - In the area occupied by circular rebar, the ITER Tokamak (23 metres in diameter) will be positioned in the centre, surrounded by its cryostat (30 metres in diameter) and concrete bioshield.
Progress is in the details
2013-09-18 - Concrete pouring will begin in October on the opposite ends of the Tokamak Pit, where workers have nearly completed the 1.5 metres of reinforcement.
Two storeys below ground
2013-09-18 - When the B2 basemat slab is completed in 2014 the Tokamak Complex will begin to rise. The lower elements of the Tokamak machine will sit two levels below the surface of the platform.
Rebar rises
2013-09-06 - A wall of rebar rises on the site of the future Tritium Building. Early in the morning on 6 September 2013—the day of the Ministerial-Level Meeting—a last interview takes place before the buses return to Headquarters.
Tokamak Pit covered
2013-09-03 - The last section of the Tokamak Pit to be covered by formwork is the lift shaft for the transfer of components between the Tokamak Building and the Hot Cell.
A lot to support
2013-08-22 - Before concrete pouring can begin, space must be set aside for embedded parts—some 60,000 anchor plates that will be embedded into the slab and walls of the Tokamak Complex to support equipment.
The basement of the Tokamak Complex
2013-08-22 - Underneath the 1.5-metre-thick concrete floor of the Tokamak Complex there will be room to move around—nearly 2 metres worth, enough for the regular inspection of the seismic pads.
A small B2 slab
2013-08-22 - A smaller version of the next-phase Tokamak Complex basemat slab (B2) can already be found on site: the 150 m2 slab mockup even recreates the various-size anchor plates that will be embedded to support equipment.
Scale mockup still in use
2013-07-24 - The Director-General of ITER, Osamu Motojima, stands with Nuclear Buildings Section Leader Laurent Patisson on top of the scale model of B2 reinforcement situtated to one side of the Seismic Pit. Here the complex pattern of steel reinforcement planned for the Tokamak Complex slab is studied.
2013-07-20 - The second basemat in the Tokamak Pit—the 1.5-metre-thick B2 slab—will be the floor of the Tokamak Complex, supporting the Diagnostic, Tokamak and Tritium buildings. The basemat should be in place by the end of the year.
Reinforcement continues
2013-07-20 - Successive layers of metal reinforcement are positioned in the Tokamak Pit. Concrete pouring will be carried out throughout the autumn.
One last section
2013-07-20 - Of the 11,700 square metre surface of the Seismic Pit, this small area is the only one not yet covered by propping, formwork and rebar. Machinery for the cask transfer lift, which will transport components between the main building and the Hot Cell, must be installed first.
Under the summer sun
2013-07-15 - Work continues in the Tokamak Pit in July 2013.
All together now
2013-07-15 - From approximately 200 people on site currently, worker numbers will rise to 1,000 at the end of the year, before climbing to 2,000, then 3,000 at the peak of construction activities.
Assembling the rebar
2013-07-15 - On the site of the future Diagnostics Building, rebar structures take their place. If all goes according to schedule, concrete pouring will begin on this side of the Tokamak Pit in August.
The thickness of the basemat
2013-07-10 - Looking at the rebar from the side, we get a sense of the thickness of the basemat that will support the weight of the Tokamak Complex.
The heart of the matter
2013-06-26 - The ITER Tokamak will sit in the centre of the Tokamak Pit, surrounded by its cryostat and bioshield. The machine will weigh 23,000 tonnes—or three times the weight of the Eiffel Tower. Photo: GTM Bâtiment Vinci
2013-06-26 - The far end of the 90 x 130 metre Seismic Pit is reserved for the Diagnostic Building—as an experimental machine ITER will have some 45 diagnostic systems. The near end rectangle will house the Tritium Building. And in the centre ... well, you don't need us to tell you. Photo: GTM Bâtiment VINCI
A bit of vertical in the horizontal
2013-06-18 - Poking up from the horizontal bed of rebar are the tops of each seismic pad.
Reinforcement work underway
2013-06-18 - In mid-June, only a small section of the Tokamak Pit still requires propping and formwork. Work is underway to position 4,000 tonnes of steel rebar—in radial/circular patterns in some areas, linear in others.
Heave ho!
2013-06-18 - Alternate layers of rebar—circular or radial—are set into place under the future ITER machine. Photo: F4E
Layer two
2013-06-18 - After the first radial pattern of reinforcement, workers are now laying concentric circles of rebar around the central point.
Metal sculpture
2013-06-18 - It's art that is appearing on the floor of the Tokamak Pit! Carefully placed, concentric circles of rebar at the exact spot where the Tokamak will be installed and assembled.
That's it, they're gone
2013-06-18 - The 493 seismic pads are now hidden from view and the Seismic Pit is no longer 17 metres deep ... With the completion of the ground support structure and the newest propping, it's more like 13 metres deep.
A wave of steel rebar
2013-05-27 - Rebar in installed in pre-decided patterns on the floor of the Tokamak Pit. Approximately two metres will subsist between the Tokamak Complex basemat and the surrounding walls, so that the entire Complex can move on its seismic pads in case of ground motion.
The shoring toolkit
2013-05-27 - Everything needed to shore up the yellow formwork is ready for the next shift: aluminum props, connectors, clasps ...
B2 basemat prep work progresses
2013-05-27 - This picture dates from late May. As of mid-June 2013, 85% of formwork has been completed and reinforcement activities are in full swing. Photo: F4E
In between the behemoths
2013-05-27 - This gap between the Tokamak Complex and the Assembly Building will permit the installation of critical networks such as electricity, piping and cooling. Photo: F4E
Careful alignment
2013-05-27 - In one corner of the Tokamak Pit reinforcement begins; for this first level, the steel rebar is held in place by temporary props. Photo: F4E
A long day's work
2013-05-26 - Fifteen metres below the surface of the platform men are at work to prepare for the B2 slab concrete pouring activities.
Storm's coming!
2013-05-26 - One afternoon in late May the storm clouds gather over the Tokamak Pit. Time to call it a day!
Propping and formwork are nearly done; reinforcement begins
2013-05-21 - Level with the top of the seismic pads, the crisscrossing of reinforcement bars gets underway in May. Four to five months will be necessary to lay 4,000 tonnes of rebar.
A strategic notch in the wall
2013-05-21 - The propping and formwork extends to the very walls of the Seismic Pit. And yet, all of these materials will have to be removed once the basemat is in place so that the seismic pads will remain accessible for inspection. How will it be done? A notch in the far wall will be the "exit door" through which the material will be removed.
Looking towards Headquarters
2013-05-21 - In just three months, the seismic columns have nearly disappeared from view. Work will begin late in May on reinforcement work in the area of the Tokamak.
End of shoring/formwork activities in July
2013-05-07 - Workers prepare for the pouring of approximately 14,400 cubic metres of concrete for the basemat of the Tokamak Complex. Photo: F4E
A rainy spring in Provence
2013-05-07 - Despite uncharacteristically poor weather, work to prepare for the Seismic Pit's second concrete basemat advances. Photo: F4E
The ITER Tokamak
2013-05-07 - The ITER Tokamak, surrounded by its cryostat and bioshield, will sit in the centre of the Tokamak Pit. Twenty-three thousand tons, that's three times the weight of the Eiffel Tower. Photo: F4E
It used to be 17 metres deep
2013-05-07 - The Seismic Pit was 17 metres deep after its excavation. But after the first 1.5-metre-thick basemat was set into place, followed by two metres of seismic columns and pads ... workers are now standing approximately 13 metres below the platform. Photo: F4E
Precision work
2013-05-07 - Reinforcement work begins in the Tokamak Pit, approximately 13 metres below platform level. The second basemat, like the first, will be 1.5 metres thick. Photo: F4E
Concrete pouring tests on mockup
2013-05-07 - The 1:1 scale mockup of B2 foundation slab reinforcement is now ready for concrete pouring tests. The challenge will be to ensure that the concrete is uniformly distributed throughout the mockup's dense metal skeleton. Photo: F4E
Heave ho
2013-05-07 - This propping, like so many broad shoulders, will support the weight of the concrete basemat that will begin to take shape in August. Once the basemat is in place, these materials will be removed. Photo: F4E
Sixth inspection since July 2011
2013-04-25 - On 25 April, the French nuclear regulatory inspectors (ASN), accompanied by one expert from the French Radioprotection and Nuclear Safety Institute (IRSN), scrutinized the ongoing works in the Seismic Pit.
A yellow sun
2013-04-25 - It's easy to see where the ITER Tokamak will sit inside of the Seismic Pit
Careful cutting
2013-04-25 - Despite the complexity of the different angles, the formwork arrives—perfectly aligned—at the level of each seismic pad.
Seismic pads, au revoir!
2013-04-12 - Mid-April, the formwork is gaining on the seismic pads. Soon, we will see only concrete.
Under the future Diagnostics Building
2013-04-08 - Built upon the same foundation, the Diagnostics and Tritium buildings will stand to one side and another of the Tokamak Building. Under the future Diagnostics Building, it's easy to see the linear pattern of the anti-seismic pads and columns, compared to the Tokamak "star pattern" at left.
Stage by stage
2013-04-03 - The B2 slab will progress in stages: propping and formwork will take place February through June, followed by reinforcement work (April through August) and concrete pouring (June through December).
Scale model of B2 reinforcement
2013-04-03 - Adjacent to the Tokamak Pit, a 150 m2 mockup has been set up to demonstrate the complex pattern of the steel reinforcement bars planned for the B2 foundation slab. Four different areas of rebar presenting specific challenges (density, complexity) will be reproduced at 1:1 scale in the mockup.
Preparatory works for the B2 slab
2013-03-22 - First silver, then yellow, then brown: on top of these aluminium props, workers will install yellow formwork, which in turn will be covered by wooden structures.
Just over their heads
2013-03-14 - Wooden formwork will be installed on top of these yellow panels. The seismic pads will be protected throughout the duration of foundation work. Photo: F4E
Looking south
2013-03-14 - Looking toward the Assembly Building worksite, where work on the foundation slab will be completed in May 2013. Photo: F4E
Moving in
2013-03-14 - Material is being moved into the Seismic Pit for propping and formwork activities: at precisely 2 metres above the first slab, the floor of the Tokamak Complex will be in place by year's end. Photo: F4E
Around every column
2013-03-14 - Four sides ... 493 columns. In order to pour a single foundation slab for the Tokamak Complex, a lot of precise formwork must be done in advance. Photo: F4E
One day
2013-03-14 - In the next years, the Tokamak Building will rise 73 metres above these columns (60 metres above platform level). Photo: F4E
Protecting the openings
2013-03-14 - In preparation for the buzz of activity planned in the Seismic Pit during the construction of the B2 slab, wooden props are going up in the penetrations of the retaining wall. These both protect workers below and protect the openings. Photo: F4E
Storage nearby
2013-03-14 - In the Hot Cell area, material is stored for the B2 prep work. Propping and formwork activities are underway and will continue through June 2013. Photo: F4E
Pointing up
2013-03-14 - The metal fingers (studs) on the top of the seismic pads will be crisscrossed with metal rebar and become part of the B2 slab. Space will remain between the two slabs for regular inspections. Photo: F4E
A rainy day in March
2013-03-07 - Taken from the fifth floor of the ITER Headquarters building.
B2 prep work begins
2013-02-27 - The basemat for the Tokamak Complex—the 1.5 metre-thick B2 slab—will sit directly on top of the Seismic Pit's 493 columns and pads. On 27 February 2013, the Central Integration & Engineering Directorate completed the challenging mission of closing B2 slab design and obtaining model approval in a meeting held with the European Domestic Agency and the Architect Engineer ENGAGE. Work began immediately on B2 propping and formwork activities in the Seismic Pit.
The last pictures of the seismic pads
2013-02-01 - These are the last pictures of the complete seismic protection system that will soon be hidden from view: formwork and propping will begin end February. Photo: F4E
2013-02-01 - Between the bottom slab (which the seismic pads rest on) and the upper slab there will be a gap of two metres. All of the formwork supporting the second slab will have to be removed through this gap. Photo: F4E
Six months to pour the concrete
2013-02-01 - By December 2013, the B2 slab—or Tokamak Complex basemat—will be in place. Photo: F4E
The Tokamak Complex will rise here
2013-02-01 - The construction consortium chosen in December to build the 360,000-tonne Tokamak Complex is establishing offices on site and working on the detailed design of the structure. As the formwork is removed from the drying basemat in November, work will begin on the civil works. Photo: F4E
Winter colours
2013-01-22 - The Seismic Pit is wearing its cloak of winter blue for this late-day photo taken mid-January. Building begins here in 2013 on the Tokamak, Diagnostic and Tritium buildings.
Back to the usual weather
2012-12-10 - Snow never lasts for long in Provence - five days after this winter's first episode, nothing remains. ¶In the foreground, deep precipitation networks are put into place more than 10 metres below the surface of the platform.
La neige?!
2012-12-07 - For the 70 people working on the foundations of the Assembly Building (see cranes in photo), work ends early on Friday, 7 December.
Early one December morning
2012-12-06 - The sun rises over the Seismic Isolation Pit. In 2013, work will begin on the foundations that will hide these columns and seismic bearings from view.
The pieces will be assembled here
2012-12-06 - The Assembly Building is a close neighbour to the Tokamak Building. Large, overhead cranes mounted on rails will run the entire length of the two buildings during assembly, along a continuous, 175 metre-long crane bay.
The ITER platform seen from 40 metres above
2012-12-03 - On the left, the Seismic Pit (with the cement batching plant in the background); on the right, the Poloidal Field Coils Winding Facility. In the foreground, CA2—the contractors area under preparation for the peak in construction activity planned in 2014-2015. © Sylvain Couturier
Pumps are working in November
2012-11-06 - The waterproof Seismic Isolation Pit is designed to keep water OUT of the foundations of the Tokamak Complex ... but as long as it's open to the sky, water also stays IN.
Ripples in the Tokamak Pit
2012-11-06 - Ten centimetres of water in the Seismic Pit attest to the heavy rainstorms that passed over Provence in early November.
The "box"
2012-10-12 - Standing above the 90 x 130 Seismic Pit, future home to the Tokamak, Diagnostic and Tritium buildings. Photo: F4E
A tall hall for pre-assembly activities
2012-10-12 - Heavy works are underway for the future antechamber to the Tokamak Building: the Assembly Building, which will house two 750-tonne cranes and pre-assembly activities.
A unique opportunity
2012-10-07 - On 6 October 2012, ITER hosts 1,300 visitors for its second annual Open Doors Day. Guests are treated to a historic walk through the foundations of the Tokamak Complex, soon to be covered over by the next-level basemat.
The hot sun of August
2012-08-22 - The Seismic Pit stands ready for the next phase of work, which should begin in 2013: the formwork, reinforcement and concrete pouring for the next-level basemat that will hide the anti-seismic bearings from view.
360,000 tonnes of building and equipment
2012-07-09 - This 90x130 Seismic Pit will support the weight of the Tokamak Complex. Made up of the Tokamak, Tritium and Diagnostic buildings, the total weight of the Tokamak Complex is estimated at 360,000 tonnes.
Assembly Hall on one side, Hot Cell on the other
2012-06-28 - In the foreground, space has been cleared and foundations set for the ITER Hot Cell building. On the other side of the Tokamak Pit: the worksite for the future Assembly Building. Photo: F4E
Assembly will take place next door
2012-06-28 - Seventeen metres above the basemat, excavation work progresses on the site of the future Assembly Hall. Photo: F4E
Please stand back!
2012-06-28 - In 2013, the seismic protection system that is now visible will be entirely covered by the floor of the Tokamak Complex. The view is impressive, but don't get too close to the edge!
The columns are actually taller than you!
2012-06-28 - It may not look like it, but each concrete column is taller than most people standing: 1.9 metres (approximately 6"3). Photo: F4E
Some serious support
2012-06-28 - Each plinth and seismic bearing assembly measures precisely 1.9 metres in height. Numbering 493 in all, they will bear the weight of the massive Tokamak Complex, estimated at 360,000 tonnes. Photo: F4E
The ITER platform in June
2012-06-13 - Work proceeds in the vicinity of the completed Seismic Isolation Pit on underground networks and on ground preparation works for the Assembly Hall.
A waterproof box
2012-06-13 - In one corner of the Seismic Pit, the three-tiered retaining walls maintain and stabilize the surrounding rock, and keep water out.
2012-06-08 - For a TV program on ITER (local French channel TLP), an interview is conducted on the precise spot where—five years earlier—a flag flew to mark the location of the future ITER Tokamak.
Pipes and cables through here please
2012-05-30 - In the completed Seismic Isolation Pit, the largest opening in the retaining walls looks onto the site of the future Hot Cell Facility. Smaller openings in the walls have been created to permit underground pipes and cables to reach the Tokamak Complex buildings.
Future Assembly Hall
2012-05-16 - Excavation work has begun in a large square area next to the Tokamak Pit, where an Assembly Hall will be constructed to house pre-assembly activities for Tokamak components.
The workers have left the Seismic Pit
2012-05-16 - After 18 months of presence, the workers have temporarily quitted the Seismic Pit for other areas of the platform: site trench work and excavation for the Assembly Hall.
Finishing touches
2012-05-16 - Final touches to the Seismic Pit in May.
Leaving no crack unchecked
2012-04-24 - The French Nuclear Safety Authority (ASN) inspects the ITER retaining walls in April 2012, verifying each crack (most of them a fraction of a millimetre deep), scratch, chipped concrete edge, and other slight departures from perfection.
Precise alignment made to look easy
2012-04-20 - A perfectly aligned row of seismic columns and pads. Photo: Engage-AP
A peek behind the walls
2012-04-20 - Between the rough face of the rock and the 15-metre-tall retaining walls, a space persists. At a later stage in the contruction works the space will be filled with sand and gravel and compacted. Photo: Engage-AP
Here it is: the completed ground support structure
2012-04-20 - The first-phase works in the Tokamak Pit are over. The next stage: the civil works on the Tokamak Complex, beginning with the creation of a reinforced basemat on top of the seismic pads. Photo: Engage-AP
Keeping the concrete warm
2012-04-20 - Special measures were put into place to keep the concrete at its minimum required temperature, including protective covers and hot air blowers at the pouring site.
Just waiting for the Tokamak
2012-04-20 - Support in the shape of a star for the ITER experimental device: the very device that aims to bring the energy of the stars down to Earth. Photo: Engage-AP
That's a tall ladder
2012-04-20 - For some on the ITER worksite. a day's work is accomplished 65 metres above ground level. Photo: Engage-AP
The walls are done!
2012-04-18 - The ground support structure for the Tokamak Complex—basemat and walls—is now complete. The retaining walls maintain and stabilize the surrounding rock and "waterproof" the Seismic Pit.
A symbolic branch
2012-04-18 - Construction on the retaining walls of the Tokamak Complex Seismic Pit ends in April. A branch is hung from one of the tallest points to symbolize the end of works—a construction tradition originating in Eastern Europe called "topping out."
Thick, thicker, thickest
2012-04-18 - From the side, it's easy to see that the retaining walls measure 1.5 metres at their base, 1.0 metres in the middle, and 0.5 metres at the top.
The centre of ITER
2012-03-15 - These workers are standing on the precise spot where the Tokamak will be assembled in a few years, several metres over their heads. Photo: F4E
An opening on one side
2012-03-15 - The Seismic Isolation Pit looking north. The break in the retaining wall to the left opens onto the future Hot Cell Facility. Photo: F4E
400th seismic bearing in the Tokamak Pit
2012-03-14 - The team from Nuvia Travaux Spéciaux (NTS) celebrates the installation of the 400th seismic bearing on 14 March.
Surveyors move in
2012-03-13 - The position of each seismic pad is verified precisely.
An army of standing columns
2012-03-13 - The concrete pillars (1.7 metres tall) and their seismic pads form an army of standing columns upon which the Tokamak Complex will be built. The area between the two concrete basemats will remain accessible for regular inspection of the seismic pads.
From bottom to top
2012-03-02 - Work on the third five-metre segment of retaining wall is nearly finished. Photo: F4E
Rebar grid
2012-03-02 - A close-up view of the dense rebar that is being laid for the Tokamak Complex basemat.
While the concrete sets
2012-02-29 - Formwork used to shape the retaining walls is supported during drying time. The space between the walls and the rock face will be filled with a mix of gravel and sand and compacted.
Now 15 metres tall
2012-02-29 - Section by section, the top, 0.5-metre-thick segment of retaining wall is set into place. Work on the walls will finish in March.
Up to the top
2012-02-29 - Workers make progress on the top third of the Seismic Pit retaining walls.
One year later
2012-02-07 - The excavation of the Tokamak Complex Seismic Pit, which required the displacement of 210,000 cubic metres of earth and rock, was completed in February 2011. One year later, progress made on construction is spectacular. Photo: F4E
Space reserved
2012-02-07 - This opening in the retaining wall will allow underground pipes and cables to reach the Tokamak Complex buildings.
Nearly there
2012-02-07 - As of early February 2012, 481 out of 493 concrete plinths had been cast (the formwork used for these 90 x 90 cm pillars can be seen in white and black in the photo). Three hundred and four plinths have now been topped with seismic bearings.
2012-02-01 - Activity in the Tokamak Pit is briefly halted as construction teams await better conditions for concrete pouring.
Looking towards the Hot Cell Facility
2012-01-19 - In this second excavated area—adjacent to the Tokamak Pit—the ITER Hot Cell Facility will be erected. Photo: F4E
Tokamak star
2012-01-12 - Among the "standing soldiers" at the bottom of the Tokamak Pit, it's easy to distinguish the future location of the machine by the spokes that branch out from a central plinth.
Second-stage pouring
2012-01-12 - The second five metres of retaining wall seamlessly join the first in one corner of the Seismic Pit.
Progress in the Tokamak Pit
2012-01-12 - The 1.5-metre-thick Seismic Pit basemat is now completed, work on the retaining walls advances, and 385 out of 493 concrete plinths have been cast.
End of March
2012-01-04 - Work on the retaining walls of the Seismic Pit should be completed by March. Photo: F4E
The final pour
2011-12-22 - Three-and-a-half months were necessary to complete the 1.5 metre-thick Seismic Pit basemat. The works underwent regular inspection: both internal audits and those conducted by the French nuclear safety regulators (ASN) have confirmed the good quality of the works.
The last segment is poured in December
2011-12-22 - The lower basemat of the Seismic Pit was completed on 22 December, as workers pour the twenty-first and final segment.
Under the ITER Tokamak
2011-12-21 - The 140 "oriented plinths" in the centre of the basemat are the last to be poured: these plinths will directly support the 23,000-ton ITER Tokamak. Photo: F4E
Careful measurements
2011-11-28 - The surface elevation, roughness (guaranteeing that the second-phase concrete will adhere perfectly) and height of the reinforcement at the top of the plinth are verified before each bearing is installed. Tolerance for these measurements is in the range of one millimetre. Photo: F4E
Double pumping
2011-11-23 - Concrete pouring for the Seismic Pit basemat progresses at a rhythm of one slab per week. The twenty-one slabs, once completed, will form a single, smooth surface.
Reinforcing the walls
2011-11-23 - Cranes lower metal reinforcement for the retaining walls of the Seismic Pit.
80% there
2011-11-23 - Late November 2011, the concrete slab at the bottom of the Tokamak Pit is 80 percent complete: 14,000 out of 17,000 cubic metres of concrete have been poured since August.
The shape of the Tokamak is distinguishable
2011-11-23 - In the centre of the Tokamak Pit, it's easy to distinguish the "spokes" of seismic reinforcement that will bear the weight of the ITER device.
A concrete box
2011-11-18 - One and a half metres thick at their base, the retaining walls will form a box around the foundation slab of the Tokamak Pit and the anti-seismic pillars and bearings. Photo: F4E
Directing the operations from above
2011-11-15 - After a prolonged rainy period, foundation work has picked up again in the Tokamak Pit.
100 bearings and counting
2011-11-15 - The installation of seismic bearing pads has passed the 100 mark and foundation pouring continues—at least on a sunny day.
The lower retaining wall
2011-11-15 - Nearly 6,000 cubic metres of concrete will be necessary for the retaining walls of the Seismic Pit. Work began mid-October and will continue through February 2012.
Precise and careful alignment for Seismic Pad #100
2011-11-06 - Early November, workers completed the installation of seismic pad number 100.
Cementing the seismic pads
2011-11-06 - Cohesion between the plinth, second-phase concrete and mortar is essential to achieve the monolithic behaviour of the structure. Image credit: ITER Organization
Solidifying the two pieces
2011-11-05 - The bearing is placed on top of a height adjustment system that enables the position, level and inclination of the bearing to be fine tuned. Topographical checks are performed before plinth and bearing are ready to receive the second-phase concrete. Photo: F4E
No air pockets allowed
2011-11-03 - Workers use vibration to render the freshly poured concrete in the Seismic Pit homogeneous and to break any air pockets.
Seismic pads, all in a row
2011-11-03 - Early November, seismic pads are installed on top of their concrete columns at a rhythm of five per day.
Steel cage
2011-10-26 - Workers finish the steel reinforcement for the retaining walls of the Tokamak Pit. Photo: F4E
Second-phase concrete
2011-10-26 - Workers guide just the right dose of concrete onto the top of each seismic pillar; this "second-phase" concrete will join the pillar to the seismic bearing. All over the Seismic Pit, this operation is being repeated 493 times. Photo: F4E
Wall pouring progresses
2011-10-26 - The first five-metre vertical segment of retaining wall has been poured in this corner of the Seismic Pit. At this level, the retaining walls are 1.5 metres thick. Photo: F4E
As large as a football field
2011-10-20 - Looking south over the football-pitch-sized Seismic Pit. To the right: the cleared area for the Hot Cell Facility. To the left: the long red line of the Poloidal Field Coils Winding Facility.
The Tokamak Pit in October
2011-10-19 - The seismic basemat—the white "floor" of the Tokamak Pit—is filled in progressively. Along the western wall, work has begun on the retaining walls (lower left).
Seismic pad layout
2011-10-18 - 493 seismic pads will protect the ITER machine and the Tokamak Complex (Tokamak, Diagnostic and Tritium Buildings). This CAD-generated image shows the exact configuration of the pads on the 1.5-metre-thick Seismic basemat. Image credit: ITER Organization
Filling in the Seismic Pit basemat
2011-10-17 - Now that the perimeter of the Seismic Pit has been filled in, work advances towards the zones in the centre.
Work on the retaining walls
2011-10-17 - Scaffolding is set into place along the rock face for work on the retaining walls of the Seismic Pit.
Looking down into the Pit
2011-10-17 - Seen from above: the construction of the Seismic Pit retaining wall.
The lowest segment is thickest
2011-10-17 - The lower five metres of retaining wall will be the thickest. From one and a half metres at its base, the wall will taper to 0.5 metres at its highest point.
15 metres tall
2011-09-30 - In six months' time, the retaining walls for the Tokamak Complex will completely cover the rock face of the Seismic Pit. Photo: F4E
A crawl space between two basemats
2011-09-30 - The "crawl space" between the Seismic Pit basemat and the Tokamak Complex basemat will permit regular inspection of the seismic pads, which are designed to last well beyond the lifetime of ITER. Photo: F4E
One month to dry fully
2011-09-30 - The concrete begins to harden in 48 hours and is completely dry in 28 days. Photo: F4E
Rebar for the side walls
2011-09-30 - Iron rebar is set into place in September for the vertical retaining walls of the Seismic Pit. Photo: F4E
Lower segment framed out
2011-09-30 - The 15-metre-tall retaining walls will be poured in three 5-metre stages; the lowest five-metre segment, seen framed out here, is 1.5 metres in width. Space between the upper segments of the concrete retaining wall and the rock face will be filled in with gravel and sand and compacted. Photo: F4E
Rubber boots and long pouring arms
2011-09-30 - Concrete pouring is carried out around metal cages that frame out a half dozen of the future seismic pillars. Photo: F4E
Work to pour the side walls will begin soon
2011-09-30 - Concrete pouring for the retaining walls of the Seismic Pit will be carried out between October 2011 and March 2012. Photo: F4E
Work on the seismic pads progresses
2011-09-27 - On the floor of the Seismic Pit, work progresses on the Seismic Isolation system for the ITER Tokamak Complex. Photo: F4E
2011-09-27 - Workers set the rebar structure into place for the retaining walls of the Seismic Pit. Photo: F4E
Phase 2 concrete
2011-09-27 - Metal formwork surrounds the fresh concrete poured between each supporting pillar and seismic pad. Photo: F4E
Temperature-controlled concrete
2011-09-27 - In order to cure the "second-phase" concrete below each seismic bearing, workers use a local heating unit to maintain the concrete temperature around 30 degrees centigrade. Photo: F4E
The final result
2011-09-19 - Atop the concrete plinth, the seismic pad has been positioned and cemented into place. When completely dry, the newer concrete will take on the exact colour of the older concrete.
Around the edges
2011-09-19 - Seismic Pit basemat pouring continues in September 2011. The areas framed out by wooden walkways are next in line to be poured.
Ten per week
2011-09-19 - On the ITER site, seismic isolation pads await installation. In the months to come, the pads will be installed at a rhythm of approximately ten per week.
The seismic pads will sit on top
2011-09-19 - A 90 x 90 cm seismic isolation pad will take its place on top of this rebar structure and be cemented into place.
Aerial view in September 2011
2011-09-14 - Looking south over the Tokamak Complex Seismic Isolation Pit in September 2011. Photo: Altivue/ITER Organization
Foundation work seen from the sky
2011-09-14 - Seismic pads fabricated in Romania and assembled in France are installed on supporting plinths in September 2011. Photo: Altivue/ITER Organization
Sandwiched between the Seismic basemat and the Tokamak Complex basemat
2011-08-30 - Each 90 x 90 cm pillar (1.7 metres tall) will support a seismic isolation pad made of alternate layers of metal and rubber. The floor of the Tokamak Complex will rest on a total of 493 pillars.
Rows of pillars
2011-08-30 - On one completed corner of the Seismic Pit basemat, the concrete pillars, or plinths, of the seismic isolation system take shape.
Welding the rebar cages
2011-08-29 - The rebar cages for the 90 x 90 cm concrete plinths are secured into place before each pouring.
493 concrete plinths
2011-08-29 - This portion of the Seismic Pit basemat has dried, and second phase work begins: the pouring of the 493 concrete plinths that will support the anti-seismic bearings of the Tokamak Complex.
Queueing up for cement
2011-08-11 - The two concrete batching plants on site are each capable of providing a flow of 100 m³ per hour. One plant serves as a backup to the other, ensuring that no disruption occurs in supply during the 12-hour pouring days. Photo: F4E
One "pour" follows another
2011-08-11 - Pouring activities begin in the north-west corner of the Seismic Pit; in the opposite corner, preparations are underway for the second day's pour planned for the following week. Work will continue—first one side, then the other—in a counter-clockwise direction until the edges of the basemat are filled in. Photo: F4E
Completing the first "lot" takes 12 hours
2011-08-11 - Some 800 m³ of concrete are poured on the first day. This 12-hour operation will have to be repeated 21 times over the next 3 months to complete the basemat of the Seismic Pit. Photo: F4E
The lower basemat
2011-08-11 - Approximately 18,000 m³ of concrete will be necessary for the 1.5-metre lower basemat of the Seismic Pit. Photo: F4E
Foundation work begins
2011-08-09 - At 5:00 a.m. on Tuesday, 9 August, foundation pouring begins to create the basemat of the Seismic Pit.
3,400 tons of metal
2011-07-28 - Thousands of metal bars like these will reinforce the foundations of the Tokamak Complex. Photo: F4E
Measuring makes it perfect
2011-07-28 - Workers measure the exact spacing of the rebar used on the floor of the Seismic Pit. Regular spacing and tying off the bars so that they remain in position are important to achieving the desired strength of the completed concrete. Photo: F4E
A single foundation for the Tokamak Complex
2011-07-28 - The three buildings of the Tokamak Complex will share a single foundation: having a monolithic structure avoids the relative displacement of process pipes crossing the buildings. Photo: F4E
Vertical bars
2011-07-28 - The vertical reinforcement bars standing five metres high against the rock face will be part of the lower retaining wall of the Seismic Pit. Photo: F4E
The work advances
2011-07-28 - Workers tie rebar into place to form the reinforced structure of the Seismic Pit basemat. Photo: F4E
2011-07-28 - Metal "chairs" are positioned on the bottom layer of crisscrossed rebar. Steel reinforcement will be built up to 1.5 metres before foundation pouring begins. Photo: F4E
Preparing the concrete plinths
2011-07-28 - Sitting atop the Seismic Pit basemat, 493 of these 1.7 metre concrete columns, or "plinths," will support the seismic pads. These, in turn, will support the basemat of the Tokamak Complex—the actual "floor" of the installation. Photo: F4E
Retaining walls
2011-07-28 - The Seismic Isolation Pit for the ITER Tokamak Complex will be composed of a basemat (1.5 metres of concrete) and thick retaining walls. Photo: F4E
Metal "chairs" are part of the reinforcement
2011-07-28 - Workers install metal "chairs" for structural stability between the lower and higher levels of crisscrossed reinforcement. Foundation pouring will begin in August. Photo: F4E
Stirrups are installed one by one
2011-07-20 - Rebar stirrups (seen in brown) linking the upper and lower rebar layers.
A rebar cage for the foundations of the Tokamak Complex
2011-07-20 - The rebar cage for the basemat of the Seismic Pit is under construction in July 2011.
How many steps down?
2011-06-22 - One of four pedestrian access staircases into the Tokamak Complex Seismic Pit. Some seventy workers involved with foundation work go up and down these staircases daily.
Blinding concrete nearly finished
2011-06-22 - In late June 2011, the blinding layer of concrete is 75% finished, and the reinforcement work progresses steadily.
The ITER platform, nearly one year into construction activities
2011-06-20 - The Poloidal Field Coils Winding Facility is seen from the north-west rim of the Seismic Isolation Pit in June 2011. Photo: F4E
"Blinding" concrete
2011-06-20 - On top of a five to ten centimetre layer of "blinding concrete," workers position steel rebar in June 2011. Some 3,400 tons of rebar is planned for the first level of foundations: the Tokamak Complex Seismic Pit basemat. Photo: F4E
The worksite in June 2011
2011-06-20 - The worksite for the Tokamak Complex Seismic Isolation Pit in June 2011. Photo: F4E
Work progresses in the neighbouring Hot Cell Facility area
2011-06-20 - Finishing touches to the Hot Cell Facility area before work begins on the blinding layer of concrete, reinforcement and foundation work, just like in the Tokamak Complex area seen beyond. Photo: F4E
Criss-cross pattern
2011-05-27 - The first level of steel rebar is positioned on the floor of the Seismic Ísolation Pit. Reinforcement for the Seismic Pit basemat will be 1.5 metres high. Photo: AIF
A thin layer of concrete
2011-05-27 - A thin layer of concrete is spread to create a clean and flat surface upon which to begin foundation operations. In the Seismic Pit, 550 m³ of concrete were necessary.
Nearly 100 kilos per bar
2011-05-27 - Four men share the weight of the 16-metre-long, nearly 100 kg steel rebar. Photo: AIF
Profiling now finished
2011-05-27 - The final bottom and façade profile is completed in May, and work begins on the blinding layer of concrete. Photo: AIF
Reinforcement work begins in May
2011-05-27 - Seventeen metres below the surface of the ITER platform, reinforcement work begins for the basemat of the Tokamak Complex Seismic Pit. Photo: AIF