Contribution to the international nuclear fusion program JT-60SA

Project Name: JT-60SA
Country: Japan
Type of Project: Testing room for nuclear fusion development

Controlled nuclear fusion is a real option for a reliable source of energy; this kind of energy is produced by the same reaction that occurs in the stars, it is environmental friendly and virtual inexhaustible.
To obtain this energy is necessary to have a gas heated to temperatures of millions of degrees, the plasma that cannot be in contact with the surfaces of the machine that contains it.
Europe, China, South Korea, India, Japan, Russia and the United States have joined their efforts in a very impressive project, ITER (International Thermonuclear Experimental Reactor), which represents a fundamental stage to demonstrate the capability of producing net power and the ability to maintain the reaction for a long enough time.
In this frame European Union and Japan launched a parallel research and development program called Broader Approach (BA) that includes the construction in Japan of the large superconducting Tokamak JT-60SA: it provides a magnetic field able to hold the plasma in suspension inside a donut-shaped structure avoiding the contact with the surfaces (magnetic confinement of the plasma) as explained before.

In Italy the activities are carried out by ENEA, as coordinator, by CNR and many Italian universities and industrial partners.
ENEA is responsible for the procurement of:
-  9 of the 18 superconductor coils that forms the magnetic system;
-  the cases for containing all the 18 coils;
-  the power supplies of the magnetic system of JT60-SA: in this scope are included also the related transformers.

SEA has been involved for the supply of two different type of transformers (cast resin and liquid immersed type):

TRANSFORMERS for FPPCC (fast plasma position control coils):
SEA transformer type: three phase cast resin transformer AN cooling
Power rating: 6000 (3000/3000) kVA
Voltage ratio: 18 / (415-415) V
Connecting group: Ddo-y11
Frequency: 54.2 - 77.6 Hz
Protection degree: IP00
No.of pcs: 2 unit system of made of  2 transformers

Each unit system has made of couple of 2 indipendent transformers, mechanically connected and parallel connected at MV side, to avoid magnetic coupling between LV1 and LV2.
These cast resin transformers have been positively tested at CESI Laboratory during July 2014.

TRANSFORMERS for CS3 - CS4 coils:
SEA transformer type: liquid immersed converter transformer ONAF cooling
Power rating: 27136 (13568/13568) kVA
Voltage ratio: 18  / (960-960) V
Connecting group: Ddo-y11
Frequency: 54.2 - 77.6 Hz
Protection degree: IP55
No.of pcs:2 converter unit system made of 2 transformers in one tank  

Recently also the liquid immersed transformers type have been tested first at SVEPPI Laboratory and later in SEA testing room passing positively the checkings.
The go-live of the project will be made in Naka, Japan in the second part of 2019.
We are very proud to have been chosen to participate in this worldwide research program that will change the scenario of the alternative sources of energy.


Source: ENEA