The Secretary shall appoint such officers and employees as may be necessary for the transaction of the business of the Corporation pursuant to civil-service laws and regulations, fix their compensation in accordance with the provisions of chapter
51 and subchapter
III of chapter
53 of title
5, define their authority and duties, and delegate to them such of the powers vested in the Corporation as the Secretary may determine appropriate. However, personnel paid by the hour, day, or month when actually employed may be appointed without regard to civil-service laws and regulations.