2013_Bulgarian_nuclear_power_referendum
A referendum on building a new nuclear power plant was held in Bulgaria on 27 January 2013.[1] Whilst it was not explicitly mentioned in the question, it was widely acknowledged that the referendum was about restarting construction at the Belene Nuclear Power Plant.[2][3]
Although the proposal was approved in all 31 electoral divisions, turnout did not pass the required 60% threshold, resulting in the referendum becoming non-binding.[4]