Educational Virtual Environments are gaining popularity as tools to enhance student learning. These environments are often used to allow students to experience situations that would be difficult, costly, or impossible in the physical world. At the Technical University of Madrid we have developed several applications to explore the use of intelligent tutors in VR. In this paper we present two of these applications which have been used for training in radiological protection in Nuclear Power Plants (NPP). These applications are inhabited by avatars and/or agents which are continuously monitoring the state of the environment and manipulating it periodically through virtual motor actions. Our applications help students learn to perform physical, procedural tasks in some different risky areas of NPP.