The Russians have nuclear-powered icebreakers. I saw numbers of them in Finland and St. Petersburg.
“By comparison, Russia has three dozen national icebreakers suitable for the Arctic, according to the U.S. Coast Guard, and China has four, including two icebreaking research ships that regularly appear at high latitudes. U.S. officials suspect those have strategic purposes.”
Russia launched two more in 2022. You know, when sanctions had crushed them and they couldn’t produce anything.