6.—(1) The condition referred to in paragraphs 3(1)(a)(i) and 4(6)(a) is that, in respect of the total amount of a substance or article described in paragraph 5(1)(a) (including any mobile radioactive apparatus) on the premises, the quantity of radionuclides must not exceed the value specified for that substance or article in column 3 of Table 4.
(2) The condition referred to in paragraphs 3(1)(a)(ii) and 4(6)(b) in respect of a substance or article described in paragraph 5(1)(b) is that—
(a)in respect of the total amount of such substances and articles on the premises, the quantity of radioactivity does not exceed the value specified in column 2 of Table 5, or
(b)no such substance or article on the premises contains a concentration of radioactivity that exceeds the value specified in column 3 of Table 5.