PEVEK, Russia — The water was hot, steamy and plentiful, and Pavel Rozhkov let it flow over his body, enjoying a shower that is not for the squeamish: On his bare skin, he was feeling the heat produced by an atomic reaction, pumped directly from a nuclear reactor into his home.

“Personally, I’m not worried,” Mr. Rozhkov said.

His shower came courtesy of nuclear residential heating, which remains exceedingly rare and was introduced in the remote Siberian town of Pevek only a year ago. The source is not a typical reactor with huge cooling towers but is the first of a new generation of smaller and potentially more versatile nuclear plants — in this case aboard a barge floating nearby in the Arctic Ocean.

As countries from across the globe meet in Scotland this week to try to find new ways to mitigate climate change, Russia has embraced nuclear residential heating as one potential solution, while also hoping it can bring a competitive advantage. Companies in the United States, China and France are considering building the type of small reactors connected now to Pevek’s waterworks.

“It’s very exciting,” Jacopo Buongiorno, a professor of nuclear science and engineering at the Massachusetts Institute of Technology, said in a telephone interview. These small reactors, he said, could also warm greenhouses or provide heat for industrial purposes. In bringing to life the new approach, he said, “the Russians are ahead.”

Nuclear-powered residential heating is distinct from running space or water heaters with electricity generated from nuclear sources. Direct nuclear heating, tried in small pockets of Russia and Sweden, circulates water between a power plant and homes, transferring heat directly from fissioning uranium atoms to residences.

Warming homes with nuclear power also has environmental benefits, advocates of the idea say. Primarily, it avoids wasting the heat that is typically vented as steam through the conical cooling towers of nuclear plants, and instead captures it for use in residential heating, if customers are fine with it.

Still, some experts are concerned about the potential risks, pointing to the many spills and accidents on Soviet and Russian submarines and icebreakers that used similar small reactors. Nuclear submarines sank in 1989 and 2000, for example.

“It is nuclear technology, and the starting point needs to be that it is dangerous,” said Andrei Zolotkov, a researcher with Bellona, a Norwegian environmental group. “That is the only way to think about it.”

Mr. Rozhkov’s wife, Natalia, was initially skeptical. They can see the new nuclear facility, which is about a mile away, from their kitchen window. She said she “worried for the first two days” after their apartment was connected to one of the cooling loops of the reactors. But the feeling passed.

“Whatever is new is scary,” Ms. Rozhkova said. Still, somebody has to be first, she suggested, adding, “We were the closest, so they hooked us up first.”

The experiment in Siberia, Professor Buongiorno said, could play a vital role in convincing countries that using nuclear power to limit climate change will require using it for more than just generating electricity, the source of about a quarter of greenhouse gas emissions.

“Decarbonizing the electrical grid will only get you one quarter of the way,” he said. “The rest comes from all these other things.”

Yes, but a nuclear shower? Professor Buongiorno said he would take one — but conceded that “obviously this is not going to work if people don’t feel comfortable with the technology.”

The experiment with nuclear heating hardly makes Russia a crusader on climate change. One of the world’s heaviest polluters, it has adopted contradictory stances on global warming, of which Pevek itself is an example: At the same time it is switching its heating to nuclear power, rather than coal, it is benefiting from climate change in the Arctic, reviving as a port as shipping lanes become more navigable.

Russians also have a long and checkered history of employing nuclear technologies for civilian applications not generally accepted elsewhere. The Soviet Union considered detonating atomic bombs to produce open-pit mines and dig irrigation canals. With its icebreakers, Russia operates the only civilian nuclear-powered surface fleet.

At several sites during the Soviet era, engineers connected a type of reactor used to create plutonium for bombs to nearby homes for heating. The reactors continued operating that way for years, even when not needed to make weapons.

The nuclear facility in Pevek is aboard the Akademik Lomonosov, a barge about the size of a city block. The idea of small reactors is not new. In the 1960s, before the antinuclear movement gained traction, they were seen as a promising technology. The United States operated a barge-based reactor to electrify the Panama Canal Zone from 1968 to 1976, and Sweden used nuclear heating in a suburb of Stockholm from 1963 to 1974.

Now, two other sites in Russia besides Pevek use nuclear residential heating; however, in those cases, it is a byproduct of large electrical plants.

Soon, in Pevek, the town’s community steam bath, or banya, will also be nuclear-powered. The Russian state nuclear company, Rosatom, connected the reactors to the heating pipes in one neighborhood in June 2020. It is now expanding the hot water service to the whole town, which has a population of about 4,500.

The plant’s two cores are cooled by a series of water loops. In each reactor, the first loop is contaminated with radioactive particles. But this water never leaves the plant. Through heat exchangers, it transfers heat — but not contaminated water — to other loops.

In Pevek, one of these loops is the system of pipes that leave the plant, branch out and supply hot water to homes.

The company promotes a number of safety features. The plant can withstand a crash by a small airplane. The vessel that holds it doubles as a containment structure. And the water circulating through buildings is at a higher pressure than the cooling loop from which it derives heat within the plant, in theory preventing a radiation leak from spreading into town.

Residents cannot opt out of getting nuclear-powered heat, but they have mostly welcomed the new plant. Maksim Zhurbin, the deputy mayor, said nobody complained at public hearings before the barge arrived.

“We explained to the population what would happen, and there were no objections,” he said. “We are using the peaceful atom.”