5.—(1) An authorisation granted under these Regulations may be granted in respect of more than one shipment, provided that—
(a)the radioactive waste or spent fuel to which it relates essentially has the same physical, chemical and radioactive characteristics; and
(b)the shipments are to be made from the same holder to the same consignee and involve the same competent authorities.
(2) An authorisation cannot be valid for a period of more than three years from the date on which it is granted.