All You Need To Know About The ITER Nuclear Fusion Reactor Project

 The French nuclear fusion reactor ITER, which is being built on an industrial scale since 2013, was recently visited by Jade, the creator of the Up and Atom channels. By housing plasma at temperatures ten to twenty times hotter than the sun’s core, the project may be able to develop a new method of producing power. It is anticipated that the tokamak reactor, which would contain plasma at temperatures of hundreds of millions of degrees, will generate 500 megawatts of fusion power—a tenfold increase in fusion discourse.

The potential benefits of nuclear fusion, which include becoming a more potent energy source than fossil fuels without the negative environmental effects, are what have piqued curiosity around the world. A family of four could get electricity for a full year using just one gramme of lithium and one water bottle full of seawater. There is no possibility of nuclear meltdowns or long-lived waste, in contrast to nuclear fission.

With a gain of 10 in fusion talk, ITER intends to release 500 megawatts of fusion power and import 50 megawatts of thermal power. The tokamak will be constructed in the Tokamak pit, where ITER is creating the world’s largest nuclear fusion device. A tokamak is a magnetically confining nuclear fusion reactor that can store 840 cubic metres of extremely hot plasma.

Two isotopes of each of hydrogen, deuterium, and tritium are injected into a huge donut-shaped chamber in order to initiate fusion in the ITER tokamak. The fuel is heated to temperatures of up to 150 million degrees Celsius, and when they fuse, the energy they unleash is of epic proportions.

Engineers must wonder, though, how they manage to hold so much plasma, as ordinary materials cannot survive those absurd temperatures. Over 200,000 times stronger than Earth’s magnetic fields, the tokamak’s enormous magnets generate magnetic fields of nearly 12 tesla. Similar to iron filings aligning with magnetic fields, plasma is electrically charged.

ITER functions as a testing ground to perfect the operational principles of a potential nuclear reactor, although it will not generate any electricity on its own.

In an actual reactor, deuterium and tritium atoms fuse to release a neutron and a helium atom, and the tokamak walls are filled with cooling fluid. Neutrons, which are electrically neutral and flow through the magnetic field directly, carry around 80% of the energy released. The fluid heats up and turns into steam when these high-energy neutrons hit the tokamak walls. Turbines spun by the steam will produce power.

In order to facilitate commercial nuclear fusion, ITER is attempting to reach extremely high temperatures. Since the facility’s founding, civil engineer Laurent Patisson, the leader of ITER’s civil engineering and interface branch, has been involved in its construction. Massive pieces of equipment that are too big to be finished offshore and transported to ITER have been sent to him, including the poloidal field coils that make superconducting magnets. Rather, they constructed a manufacturing plant on campus, and the gigantic vacuum-tight framework that will encircle the reactor and magnets was assembled in the cryostat workshop.

With end zones included, the structure is longer than an American football field and stands around 21 floors tall. In order to construct every component of the tokamak, it also houses two bridge cranes, which are among the biggest in the world with a combined capacity of 1500 tonnes. Every important lift operation has been tested beforehand.

ITER is powered by a 400 kilovolt transmission line that links to the European power grid; during times of high plasma production, this line may require up to 600 megawatts. ITER works with the power grid manager to carefully schedule the massive power draws with nearby power plants in order to assure safety. On the ITER campus, a sizable switchyard and substation receive the 400 kV line, which subsequently passes through busbars, cables and breakers to supply power to all the different structures and machinery.

Since the tokamak’s superconducting magnets require direct current, or DC, power from the grid needs to be rectified.

Two entire buildings at ITER are occupied by an AC to DC converter, with massive rectifiers devoted to each of the magnet systems. These magnets have a combined energy storage capacity of up to 50 gigajoues in their fields once they are energised. Fast discharge units are situated in this facility in case the magnets lose superconducting, a process known as a quench, and to swiftly remove that energy.

Critical safety systems and components are also needed to power pricey and fragile equipment at ITER around-the-clock. In the event that the grid fails, backup power is provided by two massive diesel generators. The movement of heat through each component of ITER is intimately related to the flow of electricity.

The campus is equipped with heating, ventilation, and air conditioning systems, and even slight variations in temperature can have an impact on the dimensions of these massive components, making assembly more difficult. The numerous components of the tokomak are kept supercool during operation by the Cryoplant, a soccer-field-sized system of helium refrigerators, liquid nitrogen compressors, cold boxes, and tanks. 

Three external heating techniques are employed to induce nuclear fusion: the first, known as neutral beam injection, uses radiation to fire particles into the plasma, where they collide and transfer energy; the other two, known as ion and electron cyclotron heating (say that three times fast), use radio waves similar to those seen in large microwave ovens. The Tokamak complex’s proximity to the RF Heating building is where those systems are situated.

Producing large amounts of heat from little amounts of tritium and deuterium is the aim of nuclear fusion research. In other words, ITER wants to extract ten times as much thermal energy from the reactor as it puts in. This is known as a Q of ten. But there isn’t a generator for electricity on the property. Rather, ITER need a method to release all of the thermal energy that they anticipate the fusion will produce. That’s what the massive cooling tower adjacent and the water cooling system are for. After passing around the tokomak, water is pumped to the tower so that it can release all of that heat into space.

When completed, the Tokamak assembly would weigh an incredible 23,000 tonnes—more than most goods trains. It’s really difficult to keep the thing up with all the heating and cooling going on. The tokomak contracts when it is cryogenically cooled, yet the structure doesn’t change in size. It must abide by all safety rules applicable to nuclear power plants because it is a real nuclear reactor. During operation, no one will be within the Tokamak complex. The structure itself is designed to survive a wide range of catastrophic events, such as explosions on the neighbouring roadway, floods, and plane crashes.

The civil engineering work on ITER at the Tokamak building has just concluded, although fusion experiments are still a ways off. They hope to eventually show that fusion has the potential to be a practical source of energy, with ten times the plasma volume of any fusion reactor now in operation. The fact that nations are working together so extensively to invest in the long-term future of energy infrastructure is exciting at the moment.