China's quest to fence off a big chunk of the South China Sea may have just gotten another, powerful boost: plans for a fleet of floating nuclear power plants that could provide huge amounts of electricity for the far-flung atolls and islets.

While floating nuclear power plants are hardly a novel idea, their use in the South China Sea - a typhoon-wracked hotbed of territorial disputes and increasing military rivalries - would be worrisome both for environmental and security reasons.

Chinese state media said Friday that Beijing plans to build as many as 20 floating nuclear power plants to supply power to remote locations. That could include offshore oil drilling rigs and the sparsely inhabited islands that China has spent the past two years building up and steadily turning into military outposts.

Floating nuclear plants have been around for decades. Most recently, Russia's Rosatom started building floating nuclear plants for use in remote locations, such as the Arctic. Those plants are powered by the same, tiny nuclear reactors used in Russia's biggest icebreakers. Indeed, China's floating plants will be built by China Shipbuilding Industry Corp., the country's biggest constructor of naval vessels, including nuclear submarines. CSIC is close to finishing Beijing's first floating reactor.

Nuclear power experts said there are few technical obstacles to converting naval nuclear plants into stationary generators; the U.S. Navy has operated nuclear-powered submarines and aircraft carriers for decades, with a sterling safety record.

"The Chinese have been operating nuclear-powered submarines for a number of years. It's not a big leap" to modify those power plants into electricity generators, said Rod Adams, who served as the engineer officer on a U.S. nuclear sub and now publishes Atomic Insights, an industry reference. He said there are "few insurmountable challenges" to deploying those reactors by 2020.

But China's nuclear plans cause concern for both security analysts and some nuclear power experts. Many Chinese initiatives, from port deals in the Indian Ocean to its frantic building in the South China Sea, ostensibly serve civilian purposes but can also mask military buildups.

In recent years, Beijing has turned tiny atolls into artificial islands, replete with military-grade airfields and, in some cases, with advanced air-defense radars. Adding a big new source of power could make those military systems a lot more powerful, potentially giving China the ability to create a no-go zone in the air and waters around its fake islands. That's especially worrisome since the United States is trying to ensure free and open access to the waters in the South China Sea, one of the world's busiest and most important trade thoroughfares.

"Nuclear reactors afloat would give the Chinese military sustainable energy sources to conduct their full panoply of operations, from air early warning and defenses and offensive fire control systems to anti-submarine operations and more," said Patrick Cronin, senior director of the Asia-Pacific Security Program at the Center for a New American Security, a think tank. Air-defense radars, in particular, could benefit from extra power, because that would increase their range.

Cronin and other security experts noted that floating nuclear reactors could also give China an extra measure of protection from any potential attacks, whether by the United States or other militaries in the region, because of the risk of sparking a nuclear disaster at sea.

That is particularly alarming because many experts fear China will try to enforce an Air Defense Identification Zone, or ADIZ, around its disputed properties in the Paracel or Spratly islands, as it did in 2013 in the East China Sea. Many security analysts are concerned that China could announce an ADIZ in the South China Sea in response to an adverse judgment from an international arbitration tribunal in the Hague that is weighing a complaint by the Philippines. That tribunal is expected to rule before the summer, and most legal experts expect the Hague will declare much of China's recent activity in the region unlawful.

The State Department said it was aware of Chinese media reports about floating reactors. "We continue to encourage all South China Sea claimants to avoid taking unilateral actions that change the status quo," a spokesperson said.

But the floating reactors also raise plenty of environmental and safety concerns, especially because the area suffers frequent powerful storms, and it is not clear what kind of mobility the floating nukes will have.

"China has already done enough damage to the maritime environment by hastily building artificial islands and destroying irreplaceable coral reefs," Cronin said. "We do not need a nuclear accident in these importing fishing grounds and sea lanes."

The concern about nuclear safety is particularly relevant in light of the 2011 meltdown at the Fukushima Daiichi nuclear power plant in Japan, which was triggered when a tsunami flooded generators that ran the safety systems. It's not clear that a floating reactor would be any more able to avoid catastrophic power outages than a land-based reactor, said Dave Lochbaum, a nuclear safety expert at the Union of Concerned Scientists.

And the risk of a meltdown at sea, while remote, could still have nasty consequences.

"Reactor core damage is never a good day, whether at a land-based reactor or one afloat," Lochbaum said. A meltdown that sent molten, radioactive material through the hull of the ship and into the ocean would be especially grim, he said. "The water is good for cooling, but not good for containment."