National Institute of Standards and Technology (NIST) hosts a 20 MW, heavy water moderated nuclear reactor, namely the National Bureau of Standards Reactor (NBSR). The NBSR control system is not equipped with a fully digital control console and the safety system of the reactor remains entirely analog. The NBSR was licensed in 1967 and modifications were implemented on the reactor console since then. Newly installed instruments have been either analog or a hybrid of digital and analog technology. Recently, the required number of digital interfaces to be installed onto the console increased rapidly. This is partly due to the lack of available replacements for analog meters, but more importantly to improve safety, operations, and maintenance. Human Machine Interface (HMI) design is a key component of these upgrades and is important for the operational performance of the NSBR reactor. There is a requirement to continuously evaluate human performance analysis while making these changes and provide operator training. Special training sessions are necessary with regards to operator actions imminent to accidents as analyzed in the updated safety analysis requirements document. The goals of this project were to allow operators to train and become familiar with the NBSR console and to allow operators to participate in safety training that would not be practical otherwise. Use of the Virtual Reality (VR) for design optimization and reactor operator training provides a modular and effective environment. To accomplish training, the VR simulator is configured to display real-time or historic-play-back data readily collected on a relational database. Computer generated data is used to simulate plant conditions during analyzed accident scenarios.