major industry is restricted to holyhead (caergybi), which until 30 september 2009 supported an aluminium smelter, and the amlwch area, once a copper mining town. nearby is the site of the former wylfa nuclear power station and a former bromine extraction plant. with construction starting in 1963, the two wylfa reactors began producing electricity in 1971. one reactor was decommissioned in 2012 and the other in 2015. plans were developed for a replacement reactor, planned by horizon, a subsidiary of hitachi, to start production in the 2020s. the replacement has been enthusiastically endorsed by anglesey council and welsh assembly members, but protesters have raised doubts about the economic and safety claims made for the plant, and in january 2019 hitachi announced it was putting development work on hold, which meant the plant's future was put in serious doubt.