The power of the Agency head to make the determinations or decisions specified in paragraphs (12) and (15) of section
2304
(a) and section
2307
(a) of title
10 shall not be delegable. Each determination or decision required by paragraphs (12) and (15) of section
2304
(a), by sections
2306 and
2313, or by section
2307
(a) of title
10, shall be based upon written findings made by the official making such determinations, which findings shall be final and shall be available within the Agency for a period of at least six years following the date of the determination.