The hidden nuclear battle between Russia and US

The hidden nuclear battle between Russia and US

The new Cold War brewing between Russia and the U.S. has the potential to go nuclear-just not in the conventional sense.

In the wake of the Ukraine crisis, a debate has ensued about whether the U.S. can use natural gas to counter Russia's global ambitions. However, some experts say the real front in the global energy battle lies not in oil and gas, but in the arena of nuclear technology.

Moscow has quietly taken the lead in the $500 billion market for nuclear exports, building the lion's share of new facilities-and by extension earning influence and good will in key regions around the globe-as the U.S. sits on the sidelines.

Fueled in part by its bounty in natural gas and oil, Russia has transferred nuclear technology to a host of countries, including Hungary, Venezuela, Turkey and, most controversially, Iran . According to the World Nuclear Association, Moscow is building 37 percent of the new atomic facilities currently under construction worldwide, while nearly doubling its own domestic output by 2020.

"The Russians view nuclear as an excellent export product," said Barbara Judge, former chair of the U.K. Atomic Energy Authority, in an interview with CNBC. "They are using it as part of their plan to establish themselves as a geopolitical economic power."

(Read more: Think US natgas can threaten Russia? Think again )

Simultaneously, the U.S. nuclear sector has fallen into an advanced state of decline. Safety and cost concerns-combined with booming natural gas supplies that are quickly becoming a staple in generating electricity-have relegated the industry to the outer limits of the nuclear sector.

Meanwhile, demand for atomic power is projected to soar in emerging markets, with Japan slowly restarting its reactors three years after Fukushima's harrowing disaster.

(Read more: Christine Todd Whitman making a case for nuclear power )

In the geopolitical chess match between Washington and Moscow, some say the world's largest producer of nuclear technology is ceding influence when it could be competing against Russia, as well as others that export nuclear technology.

"Countries that need nuclear often do not have the funds to pay for it," said Judge, who is deputy chairman of Tokyo Electric Power Company's (TEPCO (Tokyo Stock Exchange: 9501.T-JP)) reform committee. By helping countries to finance the purchase of nuclear technology, Russia, and to a lesser extent China, "are using that money as a lever to open the door," she added.

"They're selling good technology to countries that still need to train their operators," Judge said, an area where the U.S. can and should compete.