BERLIN (AP) — Rising concern over the impact of a potential Russian gas cutoff is fueling the debate in Germany over whether the country should switch off its last three nuclear power plants as planned at the end of this year. The door to some kind of extension appeared to open a crack after the Economy Ministry in mid-July announced a new “stress test” on the security of electricity supplies. It’s supposed to take into account a tougher scenario than a previous test, concluded in May, that found supplies were assured. Since then, Russia has reduced natural gas supplies through the Nord Stream 1 pipeline to Germany to 20% of capacity amid tensions over the war in Ukraine.