If a participant who is receiving a disability annuity under this part becomes reemployed to perform creditable service subject to coverage by the Cash Balance Benefit Program or the Defined Benefit Program, the disability annuity shall be terminated. The participant’s employee account and employer account shall be credited with the actuarial equivalent of the participant’s annuity as of the date of reemployment and the Annuitant Reserve shall be reduced by the amount credited to those accounts.