(1)Any person who knowingly causes a nuclear weapon test explosion or any other nuclear explosion is guilty of an offence and liable on conviction on indictment to imprisonment for life.
(2)Nothing in subsection (1) shall apply to a nuclear weapon explosion carried out in the course of an armed conflict.
(3)If in proceedings for an offence under this section any question arises as to whether a nuclear weapon explosion was or was not carried out in the course of an armed conflict, that question shall be determined by the Secretary of State; and a certificate purporting to set out any such determination and to be signed by the Secretary of State shall be received in evidence and be deemed to be so signed without further proof, unless the contrary is shown.