Saturday's eruption of Mount Ontake is likely to set back plans to restart nuclear reactors in Kagoshima Prefecture and possibly elsewhere, as local governments and residents start debating how safe the plants would be in the event of a nearby volcanic eruption.

Concern is especially high in Kagoshima, home to 11 volcanos classified as active by the Meteorological Agency.

From January to March 2011, eruptions at Shinmoedake, part of the Mount Kirishima chain, closed four railroad lines and forced the evacuation of hundreds of residents.