核生化武器與輻射散佈裝置武器(radiological dispersal device, RDD)已成為現今國際社會真實威脅。隨著越來越多的國家擁有核生化武器關鍵技術或輻射武器材料，勢將影響軍隊與社會安全，恐怖分子可於任何程度的衝突(低、中、高強度)發動攻擊，使得國家於規劃大型公共活動時必須考量核生化武器與輻射武器對於這些大型活動之影響與因應作為。本研究即在探究輻射事件在大型活動之影響及風險，以及美國對此的因應作為。本研究指出，在實際政策方面，美國等國家採取分層防禦(layered defense)戰略來防止輻射散佈裝置之，並已設計一套有效且積極性的預防戰略。

Nuclear, biological and chemical weapons and radiological dispersal device (RDD) weapons have become a real threat to the international community today. As more and more countries possess key nuclear, chemical and biological weapons technologies or radiation weapons materials, it will affect the security of the military and society. Terrorists can launch attacks in any degree of conflict (low, medium, and high intensity), making the country more difficult to plan. In large-scale public events, it is necessary to consider the impact of nuclear, chemical and biological weapons and radiation weapons on these large-scale events and their response. This research is to explore the impact and risks of radiation incidents in large-scale events, and the United States' response to this. This study points out that in terms of actual policies, the United States and other countries adopt layered defense strategies to prevent radiation dispersal devices, and design a set of effective and proactive prevention strategies.