(1) An entity whose interests are affected by a reviewable decision (other than a decision made by the Secretary personally) may apply in writing to the Secretary for review ( internal review ) of the decision.
(2) An application for internal review must be made within 30 days after the day on which the decision first came to the notice of the applicant, or within such period (if any) as the Secretary, either before or after the end of that period, allows.
(3) The Secretary must, on receiving an application, review the reviewable decision personally.
(4) The Secretary may:
(a) make a decision affirming, varying or revoking the reviewable decision; and
(b) if the Secretary revokes the decision, make such other decision as the Secretary thinks appropriate.