Works and installations containing dangerous forces are those whose attack may cause the release of dangerous forces and consequent severe losses among the civilian population. They are mainly dams, dykes and nuclear electrical generating stations. They may not be attacked, even where they are military objectives, if such attack may cause the release of dangerous forces and consequent losses among the civilian population. This special protection against attack ceases in certain specified circumstances. Reprisals against them are prohibited. Works and installations containing dangerous forces must always bear the appropriate distinctive sign. 
OUTLINE
Chapter 9, II. 9. b) cc) works and installations containing dangerous forces
Chapter 12, IV. 3. c) cc) protection of works and installations containing dangerous forces
LEGAL SOURCE
CASES
Croatia, Prosecutor v. Rajko Radulovic and Others
Colombia, Constitutionality of IHL Implementing Legislation (Paras. 2, and E.3)
Eastern Ukraine, OHCHR Report on the Situation: November 2016 - February 2017