(a)
The head of the agency concerned or his designee may settle the accounts of—
(1)
an employee for whose account payment has been made under sections
5562,
5563, and
5565 of this title; and
(2)
a survivor of a casualty to a ship, station, or military installation which results in the loss or destruction of disbursing records.
That settlement is conclusive on the accounting officials of the United States in settling the accounts of disbursing officials.