13.—(1) Paragraph 11(2)(a) does not apply to the activity carried on by a licensee of a nuclear site on any premises situated on that site at any time—
(a)while a nuclear site licence is in force in respect of that site, and
(b)after the revocation or surrender of such a licence but before the period of responsibility of the licensee has come to an end.
(2) In respect of any premises which—
(a)are situated on a nuclear site, but
(b)have ceased to be used for the purposes of an undertaking carried on by the licensee,
paragraph 11(2)(b) applies to those premises as if the premises were used for the purposes of an undertaking carried on by the licensee.
(3) Paragraph 11(2)(c) does not apply to the accumulation of radioactive waste on any premises situated on a nuclear site.