Bridging the gap between national policy and local implementation: analysis of sheltering-in-place policy development...

Preparedness for nuclear and radiological emergencies increasingly requires considering complex scenarios, including compound disasters, disruptions to critical infrastructure, and challenges in public communication. In Japan, following the Fukushima Daiichi Nuclear Power Station accident, sheltering-in-place (SIP) has been designated as a key protective action for residents within the urgent protective action planning zone. However, recent events, including the 2024 Noto Peninsula Earthquake, have highlighted operational challenges and renewed concerns regarding the implementation of SIP. This study examined SIP policy development in Japan by analysing discussions of the Nuclear Regulation Authority's 'Study Team on the Operational Use of SIP' held between April 2024 and March 2025. A qualitative document analysis was conducted using publicly available meeting records, supporting materials, the final report, and comments submitted by local governments and the public during public consultations. Findings indicate the study team clarified key operational SIP elements, including initiation, geographic scope, continuation, termination, transition to evacuation or temporary relocation, temporary outings, and information provision. However, comments from local governments and the public revealed persistent concerns regarding legal and institutional consistency, compound-disaster response, public communication, information dissemination systems, continuity of social and business activities, support for healthcare and welfare facilities, maintenance of lifelines and essential supplies, and coordination among governmental and allied organisations. These findings suggest that successful SIP implementation depends not only on technical criteria, such as dose assessment and protective action thresholds, but also on effective risk communication among governments, healthcare and welfare institutions, businesses, and residents. The principal challenge is translating national policy into locally understandable and actionable practices; strengthening stakeholder engagement, public communication, and community preparedness may facilitate this translation. Future studies should evaluate whether these measures improve practical preparedness and emergency response.