The purpose of this paper is to provide an overview of the development of the Diversity and Defense-in-Depth (D3) strategy for the TerraPower Traveling Wave Reactor, TWR-300 Advanced Nuclear Power Plant. Previously, a D3 analysis was performed for the TWR-P Digital Control System (DCS) being designed by TerraPower for the TWR-P (prototype) reactor design. This paper provides an update on the D3 report specifically applicable to the TWR-300, which will be the first TWR Plant deployed. The Instrumentation and Control (I&C) design and configuration were based on standard digital control products. The control systems making up the DCS were selected because of their applicability to the functions required by TerraPower and the United States Nuclear Regulatory Commission (USNRC). The recommended installation of a digital-based Plant Protection System (PPS) and other systems throughout the TWR-300 enhances safety in many areas when compared to the previous generation of analog-based instrumentation systems.