Del. Code tit. 11, § 8373

Upon the death of a member, inactive member, retired member or individual receiving a survivor’s pension, there shall be paid to the designated beneficiary or beneficiaries or, in the absence of a designated beneficiary, to the estate of the member, inactive member, retired member or survivor, a lump sum equal to the excess, if any, of the accumulated member contributions with interest over the aggregate of all pension payments made.