Potential Hazard of Radioactive Contamination of the Marine Environment Due to Possible Earthquakes Near the Kashiwazaki-Kariwa Nuclear Power Plant

Based on geostrophic current fields calculated from altimetry data for the period from January 1, 2013, to December 31, 2023, numerical modeling of the advection of potentially contaminated water from the Kashiwazaki-Kariwa Nuclear Power Plant to the shores of Primorsky Krai and the fishing zone around Southern Kuril Islands was carried out using a Lagrangian approach. Dasymetric maps representing probable pathways of surface ocean contamination were constructed. For the southern Primorye region, transport pathways and three corridors related to the local current structures and mesoscale eddies were identified. The minimum advection time for Lagrangian markers simulating potentially contaminated waters to reach the Primorsky Krai coast is 138-140 days. Two possible transport routes into the Southern Kuril fishing zone were revealed, with the potential for rapid advection of contaminated markers into this zone within 58-60 days. It was demonstrated that the advection of Lagrangian markers occurs in portions and within specific time windows.