(a) The judges of the superior courts, at the close of each term, in open court, shall unlock the box and break the seal and shall cause to be drawn from compartment number "one" not less than 18 nor more than 75 names to serve as grand jurors at the next term of the court, all of which names shall be deposited in compartment number "two." When all the names have been drawn out of compartment number "one," then the drawing shall commence from compartment number "two," and the tickets shall be returned to number "one," and so on alternately. No name so deposited in the box shall, on any pretense whatever, be thrown out of it or destroyed except when it is satisfactorily shown to the judge that the juror is dead, removed out of the county, or otherwise disqualified by law.

(b) In those counties utilizing mechanical or electronic means for the selection of jurors, subsection (a) of this Code section shall not apply. Rather, the judges of the superior court shall draw a grand jury from the "electronic jury box" in the same manner and under the same plan that trial juries are drawn. They shall draw not less than 18 nor more than 75 names to serve as grand jurors at the next term of court.