 In 2015, the Agency for Natural Resources and Energy changed the accounting provisions of the Electricity Business Act, so companies can account for decommissioning costs in ten yearly instalments rather than a one-time charge.This will encourage the decommissioning of older and smaller nuclear units, most of which have not restarted since 2011.Japan has had a long history of earthquakes and seismic activity, and destructive earthquakes, often resulting in tsunamis, occur several times a century.