Nuclear: from the Divertor Tokamak Test to small modular reactors, here are the projects the Italian industry is working on

To date, Italian companies have won over EUR 2 billion in orders in the field of fusion, around 50 per cent of the total value for Iter (excluding civil infrastructure). Among the companies are Asg superconductors, Cecom, Delta TI, Ansaldo, Mangiarotti, Ocem Energy Technology, Simic, Walter Tosto, Tratos, Criotec, to name but a few. Not to mention the expertise of Enea, which boasts a decades-long tradition in fusion with over 50 patents registered in the last 20 years and which coordinates the Italian fusion research programme, but which also participates in Iter and Broader Approach and devised the Dtt.

Turning instead to fission, this is a process of atom disintegration, generated by the collision between a neutron and the nuclei of very heavy (fissile, such as uranium or plutonium) atoms, which break into smaller fragments and produce neutrons that can in turn provoke other fissions, triggering chain reactions. The kinetic energy of the fission fragments is converted into heat, i.e. thermal energy, which is used to produce steam with which to power a turbine and obtain electricity. Unlike fusion, the fission process results in the production of highly radioactive waste.

On this front, Enea, in collaboration with the Italian university system (Cirten) and national industry, and in particular with Ansaldo Nucleare, the technological outpost of nuclear power made in Italy, has been conducting research and development on lead-cooled Generation IV fission nuclear systems for more than 20 years. In fact, the design and subsequent installation, at the Brasimone Research Centre, of the first experimental plants for the technological development of heavy liquid metal (lead or lead alloy) cooled systems dates back to 1999.

Turning to the much talked-about next-generation nuclear power, let us say at the outset that nuclear power plants are generally classified by 'generation' (I, II, III, III+ and IV) on the basis of the key characteristics that determined their development and industrial use. The first three generations derive from designs initially proposed for almost exclusively military naval propulsion in the late 1940s. Generation I refers to the first prototypes that launched civil nuclear power. These reactor types generally operated at low power levels. To date, there are no Generation I plants in operation. Generation II includes all those commercial, mainly water-cooled reactors, which have brought the technologies of the first generation reactors to maturity, increasing their reliability potential. Generation II systems began operating in the late 1960s and comprise the majority of the world's more than 400 commercial reactors (over 90 per cent). Generation III reactors are essentially evolutions of Generation II reactors. Improvements in technology have primarily aimed at extending their operating life, from 40 to 60 years, efficiency and further increasing their safety level. But there remains the problem of an unclosed fuel cycle, which requires geological storage of some of the spent fuel

In the fourth generation, however, the fundamental difference from the current ones lies in the coolant system that uses lead instead of water. Thanks to the physical characteristics of lead, it is possible to guarantee the presence of the coolant in any accidental condition and ensure a sustainable, safe, reliable, proliferation-resistant civil nuclear power. These goals are achievable within 20-25 years.

Midway between the third and fourth generation of reactors are the Small Modular Reactor (SMR) and the Advanced Modular Reactor (AMR). And here too, the Italian supply chain is particularly active, ranging from Ansaldo Nucleare to newcleo, via Siet and many other Italian industries and universities. The former represent the immediate response to the technical and construction difficulties of third-generation power plants thanks to their small size (which reduces the costs of safety systems while maintaining the guarantees unchanged), and modularity (which makes it possible to manufacture most of the components in a single industrial site and then ship them to the installation area). The Amr, on the other hand, derived from fourth-generation technologies, use new cooling systems (e.g. liquid lead) or innovative fuels to offer better performance and new functionalities (cogeneration, hydrogen production, solutions for closing the fuel cycle and thus nuclear waste management).