A voluntary contribution account shall be paid in a lump sum following receipt of an application therefor from a present or former participant if application is filed prior to payment of any additional annuity. If not sooner paid, the account shall be paid at such time as the participant separates from the Service for any reason without entitlement to an annuity or a deferred annuity or at such time as a former participant dies or withdraws compulsory contributions to the Fund. In case of death, the account shall be paid in the order of precedence specified in section
4055
(f) of this title.