I have not taken the trouble of looking at the bible to ascertain whether or not it is biblical. However, we must remember that as Catholics, we believe that the bible is not the only rule of Faith. We believe that the entire Deposit of Faith resides not only in the Bible but also in Sacred Tradition. Think about it, the bible itself is Oral Tradition of what the first Christian Communities founded by the Apostles were taught and believed and which were later written down. The Apostle's Creed is the short form if you will, of the longer Nicene Creed. This Creed also comes from what the Early Christians (dating back to the time of Christ) and Fathers of the Church believed and held in common. And these beliefs were later put together at the Council of Nicea, from which the Creed gets its name. You will notice in the Nicene Creed that it says "and He descended to the dead" instead of using the word hell. I do recall the nuns teaching us kids growing up that no one could go to heaven until Christ came and "released the souls" when He died.
You also should familiarize yourself with the Catechism of the Catholic Church. It explains everything
we believe as Catholics. It is online http://www.scborromeo.org/index2.html
Especially read paragraph 632 which reads: "The frequent New Testament affirmations that Jesus was "raised from the dead" presuppose that the crucified one sojourned in the realm of the dead prior to his resurrection.478 This was the first meaning given in the apostolic preaching to Christ's descent into hell: that Jesus, like all men, experienced death and in his soul joined the others in the realm of the dead. But he descended there as Savior, proclaiming the Good News to the spirits imprisoned there."
And also paragraph 633 wich reads: "Scripture calls the abode of the dead, to which the dead Christ went down, "hell" - Sheol in Hebrew or Hades in Greek - because those who are there are deprived of the vision of God.480 Such is the case for all the dead, whether evil or righteous, while they await the Redeemer: which does not mean that their lot is identical, as Jesus shows through the parable of the poor man Lazarus who was received into "Abraham's bosom":481 "It is precisely these holy souls, who awaited their Savior in Abraham's bosom, whom Christ the Lord delivered when he descended into hell."482 Jesus did not descend into hell to deliver the damned, nor to destroy the hell of damnation, but to free the just who had gone before him.483
Hope this helps