相关规则
Italy
Practice Relating to Rule 42. Works and Installations Containing Dangerous Forces
Italy’s LOAC Elementary Rules Manual (1991) provides that “specifically protected objects may not become military objectives and may not be attacked”, including works and installations containing dangerous forces such as dams, dykes and nuclear power plants. 
Italy, Regole elementari di diritto di guerra, SMD-G-012, Stato Maggiore della Difesa, I Reparto, Ufficio Addestramento e Regolamenti, Rome, 1991, §§ 7 and 13; see also § 31 (search for information).
Italy’s IHL Manual (1991) qualifies “attacks … against installations containing dangerous forces” as war crimes. 
Italy, Manuale di diritto umanitario, Introduzione e Volume I, Usi e convenzioni di Guerra, SMD-G-014, Stato Maggiore della Difesa, I Reparto, Ufficio Addestramento e Regolamenti, Rome, 1991, Vol. I, § 85.
Italy’s Combatant’s Manual (1998) states:
Works and installations containing dangerous forces (dams, nuclear power plants, chemical manufacturing, etc.) are protected by the emblem “Three bright orange circles”.
IT IS PROHIBITED to carry out hostile acts of any type against works and installations protected by this emblem; your Commanding Officer can legitimately order you to ignore the protection granted to such a work or installation if it is being used by enemy military forces, as long as there is no other way to overcome the enemy resistance and all necessary precautions are taken to avoid or limit possible damage. 
Italy, Manuale del Combattente, SME 1000/A/2, Stato Maggiore Esercito/Reparto Impiego delle Forze, Ufficio Dottrina, Addestramento e Regolamenti, 1998, § 246.
[emphasis in original]