Explainer-Could Germany keep its nuclear plants running?

FILE PHOTO: Employees work in the control room of reactor block A at the nuclear powerplant in Biblis September 18, 2008./File Photo

FRANKFURT (Reuters) - German utilities have said they may operate the country's three remaining nuclear reactors beyond their scheduled year-end closure date, but it is up to Berlin to get the ball rolling.

Power grid operators are currently stress testing the transmission system to assess the risks of an escalation in the the Russian gas supply crisis as winter approaches, with the results expected shortly.