In Japan, the criticality accident at a uranium processing plant in 1999 and the 2011 accident at the Fukushima Daiichi Nuclear Power Station, operated by the Tokyo Electric Power Company, triggered a review of the existing medical system for radiation exposure and led to the establishment of a new nuclear disaster medical care system in Japan. This system stipulates the allocation of nurses, however; there is no clear description of the roles and specific competencies required of nurses in nuclear disaster medical care. The aim of this study was to clarify nursing roles in nuclear disaster medical care by summarizing descriptions of nursing practices and roles during nuclear disasters reported in the literature to date. From eight selected articles, 182 data points were extracted and categorized using the KJ affinity-mapping method. Nursing practices were categorized as "Before Patient Admission" and "After Patient Admission". "Before Patient Admission" was further classified into the categories of "General: Admission Preparation" and "Nuclear Disaster: Admission Preparation", whereas "After Patient Admission" was classified into "General: Cure", "Nuclear Disaster: Cure", "General: Care", "Nuclear Disaster: Care", "General: System Establishment", and "Nuclear Disaster: Radiation Management". Nursing concepts were classified into the categories of "Leadership Role", "Acquisition of Specialized Knowledge", "Coordination", "Radiation Protection", and "Risk Assessment and Risk Communication".