Rod Control System (RCS) is to control position of the neutron absorbing full-length rods (control rods or rods) in Nuclear Power Plants (NPPs). Although an RCS is classified as non-safety system, there is stringent requirement for its reliability and availability to avoid an unwanted reactor trip due to a single failure of the RCS. The unwanted reactor trip caused by a single failure of the RCS refers to Single Point Vulnerability (SPV) of the RCS, which is detrimental to an NPP’s continuous and healthy operations because of significant economic impact including operation & maintenance cost. Therefore, it is important to design and implement an RCS with high reliability, availability, operability, and maintainability that can tolerate faults and defeat the SPV for NPPs. For this reason, a modern and highly reliable RCS has been developed with the goal of reducing the SPV to zero and by applying disciplined specification and implementation of design as well as comprehensive Equipment Qualification (EQ) that are consistent with the 10 CFR50 Appendix B requirements. In the modernized RCS, full redundancy controller is used in both the logic and power cabinets. The other key improvements for this modernized RCS are the adoption of dual grippers (versus a single gripper used in the old RCS) and application of DC-hold function (not implemented in the old RCS). These design and implementation aims at completely eliminating the SPV and is fulfilled through analyzing 300 SPV cases in the operating history of the old RCS, which used non-redundant control components.