The diversifying impacts of global disasters such as climate change and COVID-19 call for systematic consideration of how disasters can be addressed in different school subjects. In this paper, we discuss how the relationship between disaster and science education has been codified and framed in South Korea through an analysis of national curriculum and policy documents from the 2010s, a period marked by several human-caused disasters with lingering social impacts. A genealogical reading of policy documents reveals how disaster emerged as a curricular theme at the intersection of two policy discourses: the discourse of safety and the discourse of integration. Further analysis of the documents points to three tensions about science education that underlay this process, as disaster, a non-traditional topic, was introduced into the science curriculum. Our findings provide insights into the tensions and conflicting ideas about what should be learned in school science. We contend that a stronger theoretical and empirical base is needed when introducing new curriculum topics such as disaster into the curriculum. More effort is needed to justify the new topic against the existing aims and structures of school subjects, to consider the unique social and political context, and to bridge the gap between curriculum policy and classroom practice.