Nuclear power, the new dawn | Wired Italy

It is an old term, which appeared almost twenty years ago and was then almost canceled by the Fukushima Dai-ichi disaster of 2011. In 2022, however, due to the energy crisis aggravated by the invasion of Ukraine, people started talking about “nuclear renaissance”. In other words, the return, after a long phase of economic difficulty in the sector, of a source capable of supplying abundant, stable and zero-emission electricity.

Despite radioactive waste, a problem that should not be underestimated, the cost-benefit ratio of reactors today seems to have changed a bit all over the world: nuclear power is increasingly seen as a remedy for energy addiction from abroad and as a solution to the intermittency of wind and solarwhich only work under the right weather conditions.

In a relationship released last year, theInternational Energy Agency he conjured up”a new dawn for nuclear energy”. And he explained how, in his absence, ** the ecological transition will take place “**more difficult and more expensive”, especially from 2030 to 2050, because renewables need still high-priced storage devices (batteries). However, public opinion does not always espouse the arguments of the technicians, and the fear of waste and accidents it has sown skepticism and hostility. So to try to promote acceptance of plants by citizens, and to try to solve some cost problems that have limited their diffusion – renewables, meanwhile, are increasingly competitive – the nuclear industry is betting on new technologies.

Where are we with nuclear fusion in Europe

While the United States announces that it has produced more energy than it inputs to activate the fusion process, the international Iter project is underway in Europe, which is working on a different scale and with different objectives

The advantages of small modular reactors

The latest generation nuclear power always expects a reaction of fission, the process that has been used for decades, but in a different container. The most discussed novelty is in fact the small modular reactors (SMR), designed to be quick to make, cheap and safe. Compared to conventional systems they are smaller and much less powerful: they do not exceed 300 megawatt hours of capacity, about one-fifth of the electricity produced by a typical reactor. The modularity of the design serves to allow it mass production in factories according to standardized processes, reducing processing times and costs; traditional reactors must instead be built on the same site where they will come into operation, among thousands of workers.

Modularity, then, means ease of combination: if there is a need for a greater output, a new mini-reactor can be added to the one already active without having to change the general structure. Finally, the reduced dimensions streamline the internal trim, reducing the number of components and parts, and improve the safety. For example, the American company NuScale has devised a 77 MW reactor inserted underground in a pool of water which, in the event of a malfunction, is sufficient to absorb the heat of the fission.

There are new problems with the Italian nuclear waste

France will no longer collect our radioactive waste until we decide where and when to build a national repository. In Piedmont the construction site stops for the second time to make some irradiated liquids safe. And the government is thinking of shifting the costs of the decommissioning from the bills to the general tax authorities

New reactor technologies

However, the innovation of the Smr does not stop at the design of the systems, but also concerns the type of reactors. In some cases, such as that of NuScale, the preference for ballasts continues light waterknown all over the world and therefore facilitated in the authorization paths. Other realities have decided instead to bet on different solutionswhich do not use water as a coolant but the liquid sodium (It is the case of Terra Powerthe nuclear startup founded by Bill Gates) or helium (such as the British U-Battery and the American X-energy). Compared to water, liquid sodium has the advantage of having a much higher boiling point, lowering the risk of explosions. THE helium-cooled reactorsworking at higher temperatures than those with light water, are capable of produce not only electricity, but also heat.