Cooling Tower Area
As an experimental device, ITER will not be exploiting the heat to generate electricity. Instead, the cooling water will be transferred through a cascade of cooling loops to a high-performance heat rejection system.
Cooling water circulating under pressure through the ITER installation is responsible for removing the heat load from the ITER vacuum vessel, its plasma-facing components, and plant systems such as heating and power systems.
As an experimental device, ITER will not be exploiting the heat to generate electricity. Instead, the cooling water will be transferred through a cascade of cooling loops to the heat rejection zone located on the northern edge of the platform, where it will be cooled using an evaporative process.
One of the challenges of designing the heat removal system has been to cope with the cyclic nature of ITER operation—the daily repetition of plasma pulses lasting 500 seconds, followed by 1300-second "dwell" periods. During the "burn" phase, the peak heat load reaches more than 1150 MW while during the dwell the heat load drops off significantly (to 160 MW), creating two distinct sets of process conditions for the system to manage.
The heat rejection infrastructure is concentrated in a 6,000-square-metre area that comprises hot and cold cooling water basins, powerful pumps, heat exchangers, and an induced-draft cooling tower with ten individual cells.
The design and fabrication of the heat rejection system are part of India's procurement contributions to the ITER Project. Europe excavated the site and created the concrete basins and structures; the ITER Organization installed all the equipment.
Heat rejection
Heat generated during a plasma burn or dwell phase is collected by the Tokamak's cooling water system (TCWS) and transferred through the component cooling water system loop 1 (CCWS-1) to the heat rejection system.
Water from CCWS-1—representing 85 percent of the total heat to be managed by the heat rejection system—is pumped through heat exchangers at platform level. The open loop heat rejection system draws water from the cold basin to cool these heat exchangers and discharges it to the hot basin. During the burn phase water can enter the hot basin at up to 65 °C, while during the dwell phase the temperature remains under 35 °C.
The cooling tower is designed for a specific water inlet temperature and works most efficiently if that temperature remains relatively constant. In order to maintain hot basin temperature as close as possible to the cooling tower design temperature, the vertical pumps that cool the CCWS-1 heat exchangers are designed to substantially reduce flow during the dwell phase when there is little heat coming from the Tokamak. Vertical pumps draw from the basin and discharge to the cooling tower at a steady rate, thus using the cooling tower efficiently throughout the entire 30-minute plasma cycle.
A second cooling loop (CCWS-2) collects the heat from auxiliary plant systems such as radio frequency heating, magnet power supply, and reactive power compensation. This cooling water, typically at a much lower temperature, is sent directly to the top of the 20-metre-tall cooling tower.
The ten cells of the cooling tower can be operated independently; ITER will start operation with just four. Each 16 x 16-metre cell is filled with hundreds of layers of corrugated plastic fill and equipped with a large fan that pulls air upward. As water falls through the fill, some of it evaporates due to the strong uptake of air, removing heat. The cooled water is collected in the cold basin located under the cells; from there, it is recirculated through the CCWS-1 and CCWS-2 heat exchangers. Control functions for the heat rejection system will be primarily managed from the ITER Control Building.
To maintain the quality of the water in the circuit, part of the water is continuously discharged to the Durance River via holding basins (blowdown flow), while fresh water is added from the Canal de Provence (make-up flow). Chemicals are injected to minimize corrosion of the piping and maintain the desired pH of the water. An ozone generation system maintains a continuous injection of ozone, which consumes organic material and prevents the growth of bacteria.
More on the ITER cooling water system here.
Cooling Tower Area facts:
- Construction: February 2016-August 2018
- Area (cooling towers and basins): 6,000 m²
- Total capacity of hot and cold basins: 20,000 m³
- Cooling tower height: 20 m
- Number of cooling tower cells: 10
- Average temperature in hot basin: ≤50 °C
- Maximum total flow rate during operation: 14 m³/s
- Nominal diameter of largest piping: 2 m
- Total length of piping in cooling tower area: 5 km
- System status: operational
Photo Gallery
Letting off operational heat
2022-07-06 - This 6,000 m² area on the northeast side of the construction platform will accommodate two basins with a total volume of 20,000 m³ as well as an induced-draft cooling tower made of 10 independent cells.
Equipment installation advances
2020-12-22 - In the heat rejection zone, the ITER Organization is installing equipment supplied by the Indian Domestic Agency. Follow all installation and commissioning news on the assembly pages of the ITER website (/construction/assembly). © Les Nouveaux Médias/SNC ENGAGE
Cooling tower area
2020-06-15 - ITER's heat rejection system, including 10 cooling towers, seen from the air. © Les Nouveaux Médias/SNC ENGAGE
Towers equipped
2020-05-28 - Ten fans have now been installed at the top of the building, one for each cooling tower. Photo: ITER Organization/EJF Riche
6,000 square metres
2020-05-27 - The concrete batching plant has been removed from the platform (left) and the cooling plant is expanding into the zone. In all, it will cover a 6,000-square-metre area. Photo : ITER Organization/EJF Riche
From river to droplets and mist
2020-05-25 - Large fans at the top of the cooling tower building will induce an upward airstream that accelerates the evaporation process. Photo : ITER Organization/EJF Riche
Zigzag shape
2020-01-22 - In order to recapture the water droplets that would be otherwise scattered by the upward draft, close to 4,500 "drift eliminator" packs located at the top of each cell provide a dense, zigzagging labyrinth that forces droplets to change direction, lose velocity and fall back into the cooling tower.
Last stop
2020-01-22 - It all ends up here, in the 6,000-square-metre heat rejection zone. The squat black building to the left hosts the 10 cooling cells that are tasked with evacuating the heat generated by operation; to the right, a complex network of piping, pumps and heat exchangers connects the installation's cooling loops to the cells and the underground hot and cold basins.
First blade
2020-01-22 - Rotating at 92 rpm, a large twelve-blade fan on top of each cell induces the upward draft that optimizes the cooling process. Here, inside a newly installed fan cylinder, the fan's rotor has just been equipped with its first blade.
10t of water per second
2020-01-22 - Thirteen large vertical turbine pumps (in blue), each one powered by a 870 kW motor and capable of moving 10 tonnes of water per second, circulate water throughout the heat rejection system.
Cylinders, rotors and motors
2020-01-22 - A 3-tonne fan cylinder is being lifted into its final position above the cooling cell. The fan rotor (light grey), connected through a shaft to a 170 kW electrical motor (blue), is ready to be fitted with twelve 5-metre long plastic blades.
Evacuating 1 GW
2020-01-22 - Cooling water flows through approximately 5 kilometres of piping and 17 heat exchangers inside the heat rejection zone. At full power, the combined load that needs to be evacuated is on the order of one gigawatt, approximately half generated by the burning plasma inside the Tokamak.
Next step: large fans
2020-01-22 - At the top of the building each cooling cell is topped by a "fan cylinder." Once installed, the twelve-blade fans will induce an upward draft.
Fill packs
2020-01-22 - Inside each cooling cell, stacked layers of millimetre-thick corrugated plastic sheet (''fill pack'') act like the honeycomb structure of a car radiator. (Look closely at the black ''floor.'')
Ready to lift
2020-01-22 - Three "fan cylinders" made of fibre-reinforced plastic are ready to be lifted and installed on the roof. Each one measures more than 11 metres in diameter and weighs approximately 3 tonnes.
4,540 nozzles
2020-01-22 - A set of 4,540 nozzles sprays the water coming in from the installation's cooling system over the stacked fill-pack layers. If unfolded, the total heat exchange surface provided by the fill pack would be approximately 704,000 square metres, the approximate equivalent of 70 soccer pitches.
Cooling tower installation underway
2020-01-08 - Cooling water will flow from the Tokamak machine to the heat rejection zone (pictured) at rates of up to 14 m³/s. Equipment arriving from India is being installed by ITER Organization contractors inside of infrastructure prepared by Europe.
Installation of cooling fans
2019-12-16 - Ten 16 x 16-metre cooling cells will receive water from the hot basin and discharge it—once cooled—to the cold basin. Each cell is filled with hundreds of layers of corrugated plastic fill and equipped with a large fan (installation underway at the top of the building) that pulls air upward.
Ten cooling towers
2019-12-04 - The first two fan cylinders are positioned near the cooling tower facility, ready to be lifted to the top. © Les Nouveaux Médias/SNC ENGAGE
Preciseness counts
2019-09-23 - Each six-tonne vertical shaft must be perfectly positioned and balanced to withstand the considerable forces that the rotation of the impeller and the flux of water exert. Horizontal deflection at the bearings cannot exceed 0.05 millimetre.
10-metre-long shafts
2019-09-23 - Thirteen vertical turbine pumps will take cooling water from deep in the hot basins and circulate it either to the cold basin, or through the installation's heat exchangers. The shafts, pictured, connect the rotor (impeller) to the motor.
To be repeated 13 times
2019-09-16 - Workers install the vertical turbine pump shafts in each pump housing. The 10-metre-long shafts connect the rotor (or impeller) to a powerful 870 kW electrical motor.
Ready for use
2019-09-11 - One of 13 vertical turbine shafts is moved from storage to the heat rejection zone for installation over the hot basin.
Pumping up
2019-09-04 - ITER Organization contractors are managing equipment installation in the cooling tower zone. The infrastructure of the zone was provided by Europe; the design and fabrication of heat rejection equipment is part of India's procurement contributions to the ITER Project.
Last stop for the heat of the tokamak
2019-09-04 - Above the hot basin, contractors are supervising the installation of large lengths of piping. Over 5 km of piping is necessary to receive cooling water from the machine and plant systems and cycle it through the cooling water system, including 20-metre-tall cooling tower cells.
Basins hidden
2019-08-28 - The deep basins of the thermal rejection system were once visible in this corner of the platform. Now they have been covered over by the cooling towers (far left) and other heat removal infrastructure. © Les Nouveaux Médias/SNC ENGAGE
Pump station 1
2019-08-07 - Equipment provided by India has been installed in one of the two pump stations planned on site.
Next to be installed: large updraft fans
2019-08-06 - The cooling tower zone is taking shape. A pump station has been erected (right, near the orange crane) and large cooling fans have arrived on site for installation in the cooling tower building.
Cladding underway
2019-04-12 - The cladding of the cooling water tower is progressing. The lower sides of the structure will remain open to facilitate air flow induced by large fans on the roof. The resulting draft will cool down the water falling through thousands of corrugated plastic sheets inside the tower.
Infrastructure completed
2018-12-21 - On 21 December, the European Domestic Agency hands the completed cooling tower zone over to the ITER Organization for equipment installation. The areas handed over include the cold and hot basins, the water cooling pumping station, the heat exchange zone, and the water treatment facility.
Hot basin
2018-12-21 - During the ceremony participants were given access to the underground hot basin. During the machine's operational phase, water can enter the hot basin at up to 65 °C.
Specially designed for ITER
2018-12-12 - The cooling towers are one part of a high-performance heat rejection system that has been designed for ITER. The design and fabrication of the system is part of India's procurement contributions to the ITER Project; Europe has created the concrete basins and infrastructure; the equipment will be installed by the ITER Organization.
One structure, 10 cells
2018-12-12 - Each of the 20-metre-tall cooling tower cells will be filled with hundreds of layers of corrugated plastic fill and equipped with a large fan that pulls air upward. As water falls through the fill, some of it evaporates due to the strong uptake of air, removing heat. The dark-grey support structure for the cooling tower cells is made of pultruded fibre-reinforced polymer beams.
Heat rejection
2018-12-12 - On the northern tip of the worksite the 6,000 m² heat rejection zone is emerging. The most recent structure, in black, will house the 10-cell, 20-metre-tall cooling tower.
Rushing water
2018-10-05 - The cooling water circulating through the different cooling loops of the ITER installation will be directed toward the heat rejection zone through galleries like this. The maximum total flow rate during operation is 14 m³/s. © Les Nouveaux Médias/SNC ENGAGE
Just the tip
2018-09-05 - From this angle, we see only the structures emerging from ground level. The ten cells of the cooling tower can be operated independently; ITER will start operation with just four. © Les Nouveaux Médias/SNC ENGAGE
In September, the first structures appear
2018-09-05 - If you look closely, you'll see the first cooling tower structures rising in the fourth and fifth cooling tower cells. © Les Nouveaux Médias/SNC ENGAGE
Cooling through an evaporative process
2018-09-05 - After filtering down through the cooling towers, the water that has not evaporated will be collected in the cold basin located under the cells. © Les Nouveaux Médias/SNC ENGAGE
Cooling towers
2018-09-05 - The dark-grey support structure for the cooling tower cells is made of pultruded fibre-reinforced polymer beams. © Les Nouveaux Médias/SNC ENGAGE
Construction as art
2018-07-23 - Graphic shadows just before midday on 23 July. Photo: ITER Organization/EJF Riche
Gates to be installed
2018-04-25 - Each cold basin can be closed off individually for maintenance, thanks to giant stop log gates that will be installed over the openings on the far side. © Les Nouveaux Médias/SNC ENGAGE
The cooling tower zone
2018-04-25 - The heat rejection infrastructure is concentrated in a 6,000-square-metre area that comprises hot and cold cooling water basins, powerful pumps, heat exchangers, and an induced-draft cooling tower with ten individual cells. © Les Nouveaux Médias/SNC ENGAGE
Down below
2018-04-25 - The hot basin has been covered over, but its depths are still visible through this opening. © Les Nouveaux Médias/SNC ENGAGE
The cooling tower area, as the centre of the ITER planet
2018-04-20 - An original view of the cooling tower area, extracted from a series of drone videos taken in April. Photo: ITER Organization/EJF Riche
A few hundred metres
2018-03-13 - This photo, taken from the top of the bioshield, shows the distance that cooling water leaving the Tokamak Building will travel to reach the heat rejection zone.
Vast zone
2018-01-16 - The cooling tower area will occupy a zone of approximately 13,000 m³ on the northern corner of the platform. The tower and basin area represents about half of that; the rest is dedicated to housing pumps, heat exchangers, and other equipment. © Les Nouveaux Médias/SNC ENGAGE
New feature
2018-01-16 - A new feature on the cooling tower area: the tall columns of the Heat Exchanger Building. © Les Nouveaux Médias/SNC ENGAGE
In December
2017-12-20 - High columns are going up over the hot basin area. © Les Nouveaux Médias/SNC ENGAGE
Pipes: 5 km
2017-12-20 - Five kilometres of piping will be installed in the underground galleries of the cooling tower area. © Les Nouveaux Médias/SNC ENGAGE
Equipment arriving
2017-12-20 - Large stop log gates to close off each of the cooling basin compartments for maintenance, as well as screens to keep debris from reaching the pumps, were delivered by the Indian Domestic Agency at the end of 2017. © Les Nouveaux Médias/SNC ENGAGE
Heat rejection zone in July
2017-12-20 - All is ready in the heat rejection zone for the installation of the cooling towers. Photo: ITER Organization/EJF Riche
A widening area
2017-12-20 - The heat rejection zone is expanding under our eyes. Later, some of the equipment will be located where the concrete plant is today. © Les Nouveaux Médias/SNC ENGAGE
Not far from the fusion reactions
2017-12-20 - The heat rejection zone is just a few hundred metres from the Tokamak Complex, under construction in the background. © Les Nouveaux Médias/SNC ENGAGE
From the sky
2017-12-20 - The hot basin is now out of view, covered over by a concrete basemat and rows of columns. © Les Nouveaux Médias/SNC ENGAGE
Mapping the route
2017-12-20 - Workers cluster around plans at the end of a long workday. © Les Nouveaux Médias/SNC ENGAGE
Pump house
2017-11-17 - This small structure frames out the future pump house of the heat rejection system. © Les Nouveaux Médias/SNC ENGAGE
A thruway for pipes
2017-11-07 - These pipes are leading away from the Tokamak Complex to the heat rejection system on the northern corner of the platform. The nominal diameter of largest piping is 2 metres.
Pipes on hold
2017-10-26 - These pipes supplied by India will distribute cooling water for the heat rejection and component cooling water systems across the site. They are waiting to be connected to the above-ground piping network. © Les Nouveaux Médias/SNC ENGAGE
An evaporative process
2017-10-26 - Cooling water from the ITER facility will be pumped to the top of the cooling tower where it will slowly fall through layers of corrugated plastic fill and be subjected to a strong updraft of air. What doesn't evaporate will be collected in the cold basin, pictured. © Les Nouveaux Médias/SNC ENGAGE
Cold basin work underway
2017-10-26 - Looking over the cold basin and its five compartments. The 20-metre-tall cooling tower will be installed over this basin. © Les Nouveaux Médias/SNC ENGAGE
Under the cooling towers
2017-10-26 - The cooling tower cold basin has five compartments. Pictured: concrete pouring underway in the middle compartment in October. © Les Nouveaux Médias/SNC ENGAGE
Heat rejection zone
2017-10-26 - On site, the hot and cold basins have been created below platform level and the cold basin area has been turned over to the ITER Organization for installation activities. One of the first activities will be to install metal footings in the cold basin to prepare for the installation of the cooling tower structural members. © Les Nouveaux Médias/SNC ENGAGE
Northern portion
2017-09-30 - The heat rejection zone is situated on the northern portion of the platform between the concrete batching plant (far end) and the future ITER Control Building (area currently used for storage, foreground). © Les Nouveaux Médias/SNC ENGAGE
So many feet
2017-09-19 - Small columns in the cold basin will support the structural members of the cooling tower cells.
Underground work
2017-09-19 - Cooling water piping is stored vertically while it awaits installation. In the background work continues on the technical galleries that connect the cooling tower area to the Tokamak Complex.
Hot basin covered
2017-09-19 - This intermediate basin runs between the cold (left) and hot (right) basins. The hot basin is now completely covered over.
Status late August
2017-08-29 - The hot basin of the heat rejection system is progressively covered over. © Les Nouveaux Médias/SNC ENGAGE
Update on the cooling tower zone
2017-08-21 - The hot basin is disappearing from view. Photo: ITER Organization/EJF Riche
Layout
2017-08-21 - For the moment, all work is taking place at an underground level. However much of the equipment of the heat rejection system will be installed at platform level, including the 20-metre-high cooling tower. Photo: ITER Organization/EJF Riche
Cooling off
2017-07-13 - Work is ongoing on one of the ''final links'' of the cooling water system: a vast zone (6,000 m²) that accommodates two large basins and a cooling tower installation made of 10 independent cells. Fabrication of the cooling tower elements has begun in India.
A deep box
2017-07-13 - Seen from above, the cooling water zone at the northeast end of the ITER site.
Pipes and elbows
2017-07-13 - These supersize pipes (one metre and more in diameter) for the heat rejection system are designed for a flow rate of two cubic metres per second.
Heat rejection zone framed out
2017-07-11 - From the air we can see where the ten induced-draft cooling tower will be located (in five large bays, top) above the cold basin and, at bottom, the hot basin. © Les Nouveaux Médias/SNC ENGAGE
Buried piping
2017-06-28 - Water will travel out of the cooling water loops of the Tokamak and its systems, through these 1.6-metre-in-diameter pipes, and on to the heat rejection system. © Les Nouveaux Médias/SNC ENGAGE
The design of the heat rejection system
2017-05-31 - The heat rejection system of ITER is made up of cooling tower cells, hot and cold basins, vertical turbine pumps, a chemical dosing system, ozonator, strainers, valves and piping. © Les Nouveaux Médias/SNC ENGAGE
Looking south
2017-05-31 - From low in the cooling tower zone we can see the Assembly Hall to the south. © Les Nouveaux Médias/SNC ENGAGE
Columns in the cooling basins
2017-05-31 - The heat rejection system provides the final heat sink and rejects all heat loads in the ITER machine and plant. Its main clients are the secondary cooling circuits, the cryogenic system and the steady state electrical power network. © Les Nouveaux Médias/SNC ENGAGE
In the northern zone of the construction platform
2017-05-31 - The cold basin is compartmentalized for maintenance with each compartment collecting water from one of the cooling tower cells. © Les Nouveaux Médias/SNC ENGAGE
View of the basins
2017-05-15 - In May, the cooling water basins are completely framed out. © Les Nouveaux Médias/SNC ENGAGE
Building up from the basin
2017-04-27 - The deep cooling water basin, on the right, can no longer be seen. © Les Nouveaux Médias/SNC ENGAGE
2017-04-27 - Pre-welding operations on cooling water piping in April. © Les Nouveaux Médias/SNC ENGAGE
Cooling tower cells
2017-04-27 - Above-ground work on the ITER cooling towers. © Les Nouveaux Médias/SNC ENGAGE
Cooling tower area progresses
2017-04-10 - In April, the concrete frame of the cooling tower zone is visible from above. Besides the hot and cold basins that we see framed out, there will be quite a bit of equipment installed at platform level (the heat exchangers, for example). Photo: ITER Organization/EJF Riche
Water evaporation zone
2017-04-10 - To the right, the concrete bays reserved for 10 water tower cells and cold basin; to the left, the hot basin. Photo: ITER Organization/EJF Riche
Hot basin, seen by drone
2017-03-22 - In the photo, the lower level construction and sloped area is part of the hot basin. Vertical pumps will be installed to draw from the basin and discharge to the top of the cooling tower. © Les Nouveaux Médias/SNC ENGAGE
10 independent cooling cells
2017-03-22 - ITER's induced-draft cooling tower, under construction now, is made of 10 independent cells located above the cold basin. Each of the five bays in the photo will contain two cells. © Les Nouveaux Médias/SNC ENGAGE
Small jacket, tall wall
2017-02-28 - The yellow jacket at right helps us to judge the scale of the concrete partitions of the hot basin. © Les Nouveaux Médias/SNC ENGAGE
Partitions installed
2017-02-28 - In the foreground: technical galleries; in the background: concrete partitioning at the worksite for the cooling towers and basins. © Les Nouveaux Médias/SNC ENGAGE
Ten large cells
2017-02-28 - In the area at left, ten individual cooling cells (16 m x 16 m each, and 20 m tall) will be installed in the five large bays of the cooling tower. © Les Nouveaux Médias/SNC ENGAGE
Several entities are participating
2017-01-25 - The design and fabrication of the heat rejection system is part of India's procurement contributions to the ITER Project. Europe has excavated the site and created the concrete basins and structures; the equipment will be installed by the ITER Organization. © Les Nouveaux Médias/SNC ENGAGE
Cooling tower zone
2017-01-12 - Seen by drone, the infrastructure of the heat rejection system on the northern side of the platform. Photo: ITER Organization/EJF Riche
Concrete pouring in December
2016-12-20 - Concrete pouring is underway on the site of the cooling towers and basins.
Pouring on the northern corner of the platform
2016-12-19 - Now that the rebar is in place, pouring has started on the site of the cooling basins. © Les Nouveaux Médias/SNC ENGAGE
The two-level cooling tower worksite
2016-12-19 - The cold basin, taking shape at right, will sit under the ten cooling tower cells. © Les Nouveaux Médias/SNC ENGAGE
Ten to do the job
2016-12-02 - The structures of the ten cooling cells will sit on these concrete pedestals in the cold basin. © Les Nouveaux Médias/SNC ENGAGE
In charge of dissipating heat
2016-12-02 - Water will be used in ITER to remove heat from the vacuum vessel and its components, and to cool auxiliary systems such as radio frequency heating and magnet power supply. © Les Nouveaux Médias/SNC ENGAGE
From machine to hot basin
2016-12-02 - The hot water basin is a C-shaped structure in the lowest part of the installation. Water will arrive in the hot basin during the plasma pulses, and then be released to the cooling tower and cold basin during dwells. © Les Nouveaux Médias/SNC ENGAGE
Precision work
2016-12-02 - Rebar is set into place for the numerous concrete columns to be poured on the site of the cold basin. © Les Nouveaux Médias/SNC ENGAGE
Team work
2016-11-10 - The design and fabrication of the heat rejection system is part of India's procurement contributions to the ITER Project. Europe is excavating the site and creating the infrastructure; the equipment will be installed by the ITER Organization.
Large basins
2016-10-05 - Up to 20,000 m³ of water will be stored in the hot and cold basins of the heat rejection system. Photo: ITER Organization/EJF Riche
Starting with the foundations
2016-09-28 - A ten-unit cooling tower unit will be built here, on the northern corner of the platform. Connected to the heat removal system, it is designed to encourage a maximum amount of dissipation through evaporation. Photo: F4E
Cooling zone
2016-09-21 - After removing the heat load from the machine and its components during operation, cooling water will be transferred through a cascade of cooling loops to the heat rejection zone located on the northern edge of the platform, where it will be cooled using an evaporative process. © Les Nouveaux Médias for ENGAGE
Three zones in a row
2016-09-21 - On either side of the cooling water tower/basin worksite is the concrete plant (background) and the site of the future Control Room (foreground). © Les Nouveaux Médias/ENGAGE
On the site of the future cooling towers
2016-02-16 - On the north side of the platform, work has just begun on the site of the future cooling water basin and towers. Photo: ENGAGE
