After the recent Fukushima Daiichi nuclear power plant accident, we have initiated an effort to include a radiation class in our undergraduate public health nursing course. This study reports the content of the 180-min radiation class in 2015 for our fourth year undergraduate public health nursing students as well as the studentsʼ reflections on the class. After the class, all 63 students were invited to freely write their reflections on the class and fill in several forced choice questions. With their consent, 58 studentsʼ anonymous responses were returned and thematically analyzed. The students wrote: they realized how ignorant they had been about radiation, understood the nature of radiation, thought about social confusion and appropriate support for affected people after the nuclear accident, and they were motivated to learn more about radiation. In the forced choice part of the questionnaire, more than 97% of the students answered “agree” or “somewhat agree” to all the items about: enjoyment of the lecture, interest in the content, understanding of the topics, and willingness to learn more about radiation. Results suggested that radiation education changed the student’s attitudes towards radiation and improved their preparedness for public health challenges after radiation incidents.