The present international trend in the nuclear industry focuses on the simplification of the nuclear plants and on the reduction of the construction time. The reduced size of the most attractive modular reactors is dictated by the design target to remove the decay heat directly through the wall of the reactor vessel itself, thereby drastically reducing the number of safety-related systems.

The selected unit power of the ISIS Reactor Module (200 MWe) is consistent with this design target.

Layout studies of the ISIS power plant are in progress in ANSALDO, to optimize component arrangement and reduce erection time of the Reactor Modules and of the Balance of the Plant.

The compact reactor layout is made possible by the integrated design of the primary circuit.