Any member who elects a survivorship option for a spouse may designate a new spousal beneficiary in accordance with procedures established by the Board;  provided, that an actuarial valuation will be made following such election, and the benefit for the retiree will be recalculated so that it is the actuarial equivalent of the benefit payable to the original spouse.  Furthermore, the original spouse must be alive at the time of the change in designated beneficiary, and he or she must not be entitled to any survivor benefit under the retirement plan by operation of law.  It is intended that the Trust will pay only one survivor benefit for any member of the retirement plan and will not incur an increase in benefit costs by reason of change in designated beneficiary.