Big buildings

Laurent Patisson is one of those new arrivals at ITER who has actually been in the ITER loop, one way or another, for quite some time now. Laurent, who is a Civil Engineer, specialized in seismic building techniques. When he started working in nuclear building design at the CEA six years ago, his main project was to conduct site studies for ITER at Cadarache with respect to the seismic risk of the Tokamak Complex building. In 2005 he then conducted additional studies related to the Tokamak Complex and as one thing led to another, Laurent became an ITER employee three months ago in October 2007.

Within the Civil Construction and Site Support Office, Laurent and his colleague Yoshiyuki Mita are responsible for the design of the Nuclear Buildings, which include the Tokamak Complex and the Assembly Building, the Hot Cell, the Radwaste and the Control buildings. They are also coordinating the various systems interfaces.

Talking to Laurent, one quickly gets impressed by the sheer magnitude of what will be the "safe" that will contain the Tokamak. The building dedicated to contain the machine, with walls that are 1.5 metres thick, will have a surface of 110 by 80 metres, approximately the size of soccer field, and will be 75 metres high (about a 20 floor building). To support this megastructure, the concrete foundations will be up to 5 metres thick, about the height of a 2-floor building, and will be supported by 700 aseismic pads, to make sure the Tokamak Complex is earthquake-proof.

All connections in and between buildings will also have to be flexible to support possible seismic activity. The levelling to create the platform for the building will start in March or April of this year. The Tokamak Complex will be placed in an 20 metre deep hole, for which excavation works will begin early 2009. The building is planned to be ready by 2013 even though, because of its sheer size, some of the Tokamak elements will have to be fitted in even before the building is ready. "Working on this project is a once-in-a-lifetime challenge," says Laurent, because we are actually breaking new ground and setting the standards for something that has never been done before."