On 25 May 2011 the Swiss government announced that it plans to end its use of nuclear energy in the next 2 or 3 decades. "The government has voted for a phaseout because we want to ensure a secure and autonomous supply of energy", Energy Minister Doris Leuthard said that day at a press conference in Bern. "Fukushima showed that the risk of nuclear power is too high, which in turn has also increased the costs of this energy form." The first reactor would reportedly be taken offline in 2019 and the last one in 2034. Parliament will discuss the plan in June 2011, and there could be a referendum as well.

Answer this question, if possible (if impossible, reply "unanswerable"): What reason did the Swiss government give for ending its use of nuclear energy?
to ensure a secure and autonomous supply of energy