WSC has completed the upgrade of Safety System #3 of Rivne Nuclear Power Plant Unit 3 Full-Scope Simulator (FSS). The greatest challenge was integrating a new Distributed Control System (DCS) for the reactor and Turbine Islands. The DCS for Unit 3 is designed, manufactured, and implemented by a Ukrainian supplier, RADIY. During the implementation of RADIY DCS on the FSS, WSC identified multiple discrepancies in Instrumentation and Control (I&C) and Operating Procedures, making the work essentially an SAE project. Working with the plant personnel and RADIY specialists, WSC stressed the necessity of validating the logic using FSS high-fidelity dynamic models, which uncovered issues that were corrected before installation. WSC recently signed a contract to upgrade Safety System #2 of the Rivne Nuclear Power Plant Unit 3 FSS.