unable or unwilling to serve, the individual shall, subject to subsection (c), repay the funds received, or serve a period equal to the military service commitment in a federally sponsored national service program. (c) Waiver The Secretary of a military department may reduce or waive the service obligation of an individual under this section in exigent circumstances, as determined by the Secretary. (d) Relation to other personnel authorities A grant under subsection (a) may be provided— (1) without regard to the lack of authority for the grant under title 10 or 37, United States Code