The French environment minister, Ségolène Royal, said on Monday that work will begin this year to shut down the country’s oldest nuclear power plant, at the centre of a row with neighbouring Germany and Switzerland.

In doing so she implicitly contradicted a Green party minister who had said on Sunday that the process to close the Fessenheim plant in Alsace would be completed, rather than merely started, by the end of the year. The two ministers spoke to the French media after a row sparked on Friday when Germany demanded that France close down Fessenheim following reports that a 2014 incident was worse than earlier portrayed. Royal said on the TF1 television channel that shutting down a nuclear reactor “is not just turning off a tap” and involved not only time-consuming official paperwork but careful decommissioning under strict safety conditions, along with collateral issues such as the question of job losses. “A nuclear plant like Fessenheim employs 2,000 people,” she explained, saying the site could eventually be converted for renewable energy, or maybe a car factory. On Sunday France’s housing minister, Green party member Emmanuelle Cosse, had said that closing Fessenheim this year was “the timeline ... the president [François Hollande] has repeated to me several times”. “The process of stopping a reactor is simple enough,” she added. France’s Nuclear Safety Agency has said that safety at the plant was “overall satisfactory” but that the government’s energy policy “could lead to different choices” regarding the facility, which is near the German and Swiss borders. It said there was “no need” to shut the plant from a nuclear safety point of view. France has promised to cut reliance on nuclear energy from more than 75% to 50% by shutting 24 reactors by 2025, while stepping up reliance on renewable energy. Fessenheim, located on a seismic fault line, has worried French, German and Swiss environmentalists for years. In September, Hollande said the plant, in operation since 1977, would not be shut this year, contrary to a 2012 campaign promise, because of delays in completion of a new plant in northern Flamanville. On Sunday, Cosse said that to reach its target, the government would have “to close other nuclear plants, other reactors, obviously, over several years.”