(1) Section 3 of the Special Constables Act 1923 (c. 11) shall have effect as if all nuclear sites that are not for the time being designated under subsection (2) were premises under the control of the United Kingdom Atomic Energy Authority.
(2) The Secretary of State may by order made by statutory instrument designate any nuclear sites which appear to him to be used wholly or mainly for defence purposes as premises to which subsection (1) does not apply.
(3) An AEA constable shall have the powers and privileges (and be liable to the duties and responsibilities) of a constable anywhere within 5 kilometres of the limits of the nuclear sites to which subsection (1) applies.
(4) An AEA constable shall have the powers and privileges (and be liable to the duties and responsibilities) of a constable anywhere it appears to him expedient to go-
(a) in order to safeguard any nuclear material which is being carried (or being trans-shipped or stored incidentally to its carriage) before its d