Related Rule
Togo
Practice Relating to Rule 42. Works and Installations Containing Dangerous Forces
Togo’s Military Manual (1996) states that it is prohibited
to attack dykes, nuclear power plants and dams, if such attack would release dangerous forces which may cause severe losses among the civilian population, unless these works have been used in direct support of military operations or for military purposes and an attack on these objectives is the only way to terminate such use. 
Togo, Le Droit de la Guerre, III fascicules, Etat-major Général des Forces Armées Togolaises, Ministère de la Défense nationale, 1996, Fascicule III, p. 13.