Civil Support Teams (CST) must be ready to respond to a variety of potential situations involving dangerous materials. For many of these materials, standard real-world training methods can be successfully employed. Training involving radiological agents, however, poses a greater challenge than for other agents due to a lack of materials that can suitably mimic the situation without the danger of the real material. To address the need of providing a good training system for learning how to behave when responding to a radiological threat, we have developed a CST immersive training system. Our system simulates a radiological threat in a virtual environment and allows users to practice surveying the threat using virtual representations of the world and necessary equipment. We developed novel multi-user interaction techniques to enable simultaneous training for two CST members. The 92ndCST tested the system and provided feedback throughout the development process. The team learned to use the system with little coaching, quickly learned to navigate and interact via wand controls, and ultimately performed a successful demonstration of a radiological survey using our system for their superior officers.