In April 2017, CDC is participating in a National Level Emergency Exercise called Gotham Shield, led by the Department of Homeland Security, practicing a response to the detonation of a 10kt Improvised Nuclear Device. Planning for the public health communications response began well before the official exercise planning. This exercise was the first time CDC used a model called a “First Strike Plan” to give communicators a handbook of response tools for the first 72 hours. This tool was used to jumpstart a smooth, coordinated response to an understandably chaotic situation. Communication for a radiation event requires near-instant action to let people know how to protect themselves, their families and their pets. To save lives during a nuclear or radiological event, messages on this complex topic must be delivered in a timely manner under extremely challenging circumstances, including the potential loss of traditional communications channels. Messages must also be coordinated with a wide range of partners. This presentation will discuss the model of using a First Strike Plan, the unique challenges of communicating during a radiation disaster, and the use of this model during the National Level Exercise, including lessons learned and potential applications for other types of emergencies.