Quantum tunneling dynamics of a periodically driven symmetric double-well system is studied within the framework of the Floquet theory. The role that a dynamical symmetry of the system plays in connection with tunneling is analyzed. The analysis shows that, in order to fully describe tunneling exhibited by a system with a dynamical symmetry, one should look at wave functions at times corresponding to integral multiples of the period of the driving force plus one-half period. The analysis shows also that tunneling can be understood to occur as a result of the quantum revival, a phenomenon well known in quantum optics.