Investigation of transient voltages in a Tokamak building hit by lightning

The ongoing international Tokamak (nuclear fusion) demonstration project (ITER) will be housed in a building supported by a 17 m deep complex seismic isolation pit. This 120 m long and 90 m wide pit will house the anti-seismic foundations of the future Tokamak Complex. Safety to persons in contact with the building and damage to the anti-seismic foundation structures due to repeated lightning strikes is a major concern and must be prevented by adequate lightning bonding and grounding mitigation measures. This paper describes the results of a detailed study of the response of the Tokamak building structures and associated anti-seismic pit foundations structures to lightning strikes. This paper focuses on the transient response and related safety aspects.