In addition to the contributions deducted from compensation as hereinbefore provided, subject to the approval of the board of trustees, any member may redeposit in the members' contributions account by a single payment an amount equal to the total amount which he previously withdrew therefrom as provided in this chapter. Such amounts so deposited shall become a part of his accumulated contributions in the same manner as if said contributions had not been withdrawn.
T.C.A. § 49-1525