It’s December 11; the eyes of the world scientific community is turned towards California; physicists, researchers and science enthusiasts are hanging on an indiscretion of the Washington Post: the most important newspaper in America has announced a "breakthrough" about nuclear fusion, thanks to a test conducted on 5 December by the Lawrence Livermore National Laboratory. More news will follow the next day, in a press conference that promises to be historic.
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Before knowing the outcome of this research, it is good to make some premises. In Italy, nuclear energy has been, and still is today, albeit in minor tones, a strongly divisive issue (the 1987 referendum is the apex of it): political parties of all colours have polarized the debate, sacrificing scientific facts for electoral gain. As L’Avvocato dell’Atomo, aka Professor Luca Romano, states in his book of the same name (Fazi editore, 2022): "in the ranking of who enjoys the worst press, nuclear energy ranks between the Camorra and ISIS, but without having done anything to deserve it". In order not to further fuel this fury, therefore, it is better to ask some questions (for further clarity in the answers, again refer to the channels of the Avvocato).
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Let’s start with nuclear fission: how does it work?
If the nucleus of a "heavy" element like uranium is hit (given the war references, I will not use the more correct technical term "bombarded") by neutrons, this is divided into two fragments that repel, generating energy. Neutrons that "disperse" from this impact can in turn generate a fission chain. The energy manifests itself in the form of heat that, by heating water, produces steam, which in turn moves a turbine. From mechanical to electrical energy: this is what happens in a nuclear power plant. The advantages of this energy supply lie in the fuel-energy ratio produced: 1 gram of uranium so treated produces the same amount of energy that is produced with 2800 kg of coal, with very low gas emissions! (no, it is NOT zero emission). So where is the problem? Actually, there are mainly two. The first concerns the supply of fuel: the largest uranium deposits, in fact, are located in Canada, Australia and Kazakhstan; very few if any in Europe. If today we have noticed the problems that years of no-diversified energy policies, focused on a few large suppliers (Russia for gas, Arab countries for oil), have produced for the European economy, who can assure us that tomorrow the same will not happen with these countries?
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The second concerns the production of radioactive waste, of various dangers, during the reaction: these must be stored in ad hoc storage for a long time (we are talking about numbers up to the order of hundreds or thousands of years) before being completely disposed of, so that the radioactive charge decays. It is precisely this second aspect that scares the public most: incidents such as Chernobyl in 1986, Fukushima in 2011 (the latter, for clarification, was not caused directly by the earthquake but by the subsequent tsunami) Three Mile Island, 1979, helped demonize nuclear technology. Warning: it is one thing to condemn the bad management of the plants and human error, quite another story is not to recognize the benefits of this energy source that, as in most cases, is controlled in the best possible way.
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Nuclear fusion is very different.
Two atomic nuclei, which in nature are positive therefore tend to repel, are forced to combine with each other: this is easier if you use "light" elements such as hydrogen, which has an electromagnetic charge (the force that tends to drive away the atoms) minor to fight. The energy produced is then used, as in fission, to move a turbine. To "bring" atoms closer together and start the reaction, very high temperatures are needed (we are talking about millions of degrees), so much energy to start the process: on December 5 last entered history precisely because, For the first time, it was possible to produce more energy than was needed to start the fusion.
But what would be the advantages of this technology? First of all: hydrogen is much more available than uranium because it is contained in water; therefore, an outlet to the sea is sufficient for the supply. No nuclear accident: uranium is not used, and especially if the temperatures necessary for the operation of the reactors are not maintained, the plant goes out of operation. Finally, more reassuringly, low-level waste is produced.
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According to European scientists, this is a technology that is far away, that can be improved and that is expensive: it is difficult, in fact, to foresee a future in which the energy supply will depend only on this source; more likely (and desirable) than is accompanied by renewables. Yet, during the conference on 11 December, the tone was quite different overseas, at times worrying.
One could overlook the megalomaniac and self-referential tones with which the United States speaks of this result, compared in importance to the "flight of the Wright brothers" or the discovery of the "Holy Grail" of science. We could even turn a blind eye to the words of Tammy Ma, the physicist at the head of the IFE (Inertial Fusion Energy) laboratory: in line with the America first principle, he talks about a technology that is accessible to everyone and can meet the world’s energy needs, but above all that it can "provide the energy sovereignty and energy security of the United States".
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To worry instead are the sentences of Jennifer Granholm, Secretary of the Department of Energy of the United States of America, who has expertise in the civil and military. Two minutes into the conference, he said:
What does this accomplishment do? Two things.
First: it strengthens our national security because it opens a new realm for maintaining a safe, secure and effective nuclear deterrent in an age where we don't have nuclear testing.
Ignition allows to replicate for the first-time certain condition that are found only in the stars and Sun.
The second thing, of course, it’s that this Milestone moves us one significant step closer to the possibility of zero carbon abundant fusion energy, powering our society.
Reversing the order of the addends, the result changes! Immediately underline the possible military application, not even ten days after the test and, above all, in an international political climate, to say the least, glowing, must make us reflect.
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But to nip in the bud such a technology, would not mark a turning point, a cooling, polarization of the debate. As Professor Amaldi, Cern physicist and son of Edoardo, one of its promoters, said in an interview with Corriere "today is the time of optimism": it is therefore necessary to invest in research as is being done at the ITER of Cadarache in France, a European project aimed at the construction and use of an experimental fusion reactor. With the hope that the scientific community can make the best use of the energy that, paraphrasing Dante’s Comedia, "che move il sole e l’altre stelle".
Images: Jakob Madsen su Unsplash
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