6.—(1) Where an assessment has been made pursuant to regulation 4(1) by an operator or carrier—
(a)the operator in question shall send to the Executive a report of that assessment at least twelve months before the commencement of the work with ionising radiation to which the assessment relates or within such shorter time in advance as the Executive may agree; and
(b)the carrier in question shall send to the Executive a report of that assessment at least 28 days before the commencement of the work with ionising radiation to which the assessment relates or within such shorter time in advance as the Executive may agree.
(2) Where an assessment has been made pursuant to regulation 5(1), the operator or carrier in question shall send to the Executive a report of that assessment within 28 days of the making of the material change or such longer time as the Executive may agree.
(3) Where an assessment or declaration has been made pursuant to regulation 5(2), the operator or carrier in question shall send to the Executive a report of that assessment or the declaration, as the case may be, within 28 days of the assessment or declaration being made.
(4) A report of an assessment made for the purposes of this regulation shall include the particulars specified in Schedule 5.
(5) Where, for the purpose of assessing the risk to health or safety of persons who could be affected by work with ionising radiation to which regulation 4 applies, the Executive may reasonably require a detailed assessment of any of the further particulars set out in Schedule 6, it may, by notice in writing served on the operator or carrier, require him to carry out (or, in relation to a carrier, require him to ensure that there has been carried out) such detailed assessment of such matters as are specified in the notice and the operator or carrier, as the case may be, shall send a report of that assessment to the Executive within such time as is specified in the notice or within such longer time as the Executive may subsequently allow.