To facilitate the energy transition, the conventional baseload nuclear power must be equipped with flexibility. By integrating grid-scale energy storage systems to the existing nuclear plants, they can curtail their load to avoid surplus generation. Liquid air energy storage (LAES) has been steadily investigated for their advantages, and this paper suggests an integrated layout using mechanical drive steam turbine and packed bed energy storage systems. Possible options for integration of LAES to the existing nuclear steam cycle are considered. The performance of packed bed storage systems is analyzed using transient modeling, and the results are fed into the overall cycle design using an in-house code. The results of the analysis suggests that the concept can reach up to 45.7–59.8% in round-trip efficiency, under much simplified cycle layout than the reference LAES layouts.