Entering the stage, one by one

Commissioning is the final check that each of the components and plant systems have been designed, manufactured and installed correctly. It is an opportunity to transfer knowledge to the operations team, test all the procedures, and get ready to start the first experiments.

To commission a facility as complicated as ITER it is necessary to proceed in small and gradual steps—checking each part before moving onto the next, and bringing together more and more pieces of the puzzle until the whole facility is working as one. At that point we will be ready to turn on the Tokamak and make plasma.

We will start this year by energizing the electrical distribution systems, since without electricity nothing can work. ITER is directly connected to France's 400 kV public transmission network. Transformers and switchgears located on the ITER platform will "propagate" this power all over the site to provide the correct voltage for each of the clients.

Last year, a test was performed with the first energization of a 400 kV bay, in order to validate all procedures and contractual requirements with French transmission system operator.

Once power is available, the central control system will be turned on and made ready to control, monitor and record data from each of the systems to come. The first task for the control system will then be to start up the cooling water systems and the cooling towers, testing each pump and valve before starting the circulation and flow tests.

First commissioning task: electrical distribution

Commissioning of electrical supplies will begin this year with the energization of the four 400 kV transformers connected directly to the French national electrical network, an operation that will be performed jointly with RTE (Réseau de transport d'électricité), the transmission system operator. These transformers will then be used to progressively energize the 22 kV switchgear for distribution of this "steady-state" baseline electrical supply to the load centres spread around the ITER site serving different client systems. Later, this process will be repeated for the transformers providing the 66 kV and 22 kV supply to the pulsed power network for the superconducting magnets and other systems that require the supply of electricity during a plasma pulse.

With power, control and cooling in place we will begin commissioning the production and distribution networks for various gases and liquids, as well as the air conditioning to remove heat generated by the plant in each building. We then start up the nitrogen and helium production facilities in the cryogenic plant and the various auxiliary vacuum pumping systems.

The specialized Tokamak systems come next—the electron cyclotron system that generates megawatts of microwave energy to heat the plasma, cryogenic pumping systems able to produce ultra-high vacuum, and the power supplies needed to energize the superconducting magnets.

When all of these systems have passed their tests we are ready: the construction phase of ITER is complete and we can start the operations phase with integrated commissioning of all systems working together. All air will be evacuated out of the vacuum vessel and cryostat to bring the pressure inside to one millionth of normal atmospheric pressure; the magnets will be cooled down to -269 °C and energized to create the magnetic confinement field; and a tiny amount of hydrogen gas will be injected and heated up to produce a critical milestone for ITER—First Plasma.

Once this has been achieved we will press on—turning up the current on the magnets to full power and completing their stress testing under all the various field combinations.

At that point we will have shown that the ITER machine is ready for the researchers.