The nuclear issue is one of the most hotly debated topics of the last century:

has been a technology used with disastrous effects in the military sphere (World War II, the famous atomic bombs of Hiroshima and Nagasaki), but it is also used for the production of electricity through the construction and exploitation of special nuclear power plants, which have also, in rare cases, been the protagonists of some tragedies (see Chernobyl in 1986 and Fukushima in 2011).

But how does nuclear energy production work?

Without going into excessive technicalities, nuclear energy is the energy released during the transformations of atomic nuclei, transformations that can be obtained through the processes of fission or fusion of the atom.

The most heated debate on nuclear energy is that of the sustainability of nuclear power itself and its pros and cons for modern Society ; there are two main factions at play:

• There are those who believe thatnuclear energy is safe and, above all, that it can be considered sustainable as it would significantly reduce CO2 emissions into the atmosphere; it would also allow easier access to electricity and would promote the energy independence of any country that decides to use it.
• On the other hand, there are those who argue that the impact that nuclear power would have on thesurrounding ecosystem would be profoundly negative, putting both biodiversity and people at risk. There is also the problem of the difficulty of disposing of the radioactive waste produced by nuclear power plants. This waste is highly harmful and dangerous and requires large isolated areas where it can be stored and maintained for over 30 years.

The topic of nuclear energy and its exploitation is mainly addressed through the exclusionary approach:

• Excluded from the portfolios are Society which are related to the mining, conversion, enrichment and disposal of uranium and other radioactive materials or which are involved in projects for the expansion or construction of nuclear power plants. The tolerance thresholds are around 5% and in some cases even zero.

In the area of nuclear weaponry, on the other hand, in addition to the exclusion of Society producing or selling nuclear weapons, the regulatory approach is also used:

• Linked to the signing and implementation by Sovereign States of the 1968 Nuclear Non-Proliferation Treaty (NPT), which provides for the non-proliferation of nuclear weapons, disarmament and peaceful use under the supervision of an international body, the IAEA.

In the sustainable funds we analyzed, there is no consensus on this issue as 32 percent of the funds place some limitation related to nuclear energy :

• 25% of the funds exclude activities related to the construction or operation of nuclear power plants (nuclear-derived electricity)
• 23% of funds exclude activities involved in the extraction, sale and storage of nuclear and radioactive materials