YONHAP / EPA South Korean President Park Geun-hye receives U.S. Secretary of State John Kerry in Seoul on April 12, 2013

When South Korean President Park Geun-hye visits Washington on May 5 she will be reaffirming the 60-year alliance between the U.S. and her country with cordiality. Relations between Washington and Seoul are better than ever thanks to a free-trade agreement, greater policy coordination and solidarity against North Korea’s provocations. But there is an unresolved question in their relationship: How much nuclear technology should South Korea possess?

Representatives from both countries have tried to answer that question since October 2010, when they started negotiating over the 1974 nuclear-cooperation agreement, which permits commercial nuclear trade between the two nations. Under the pact, South Korea is banned from reprocessing spent U.S. fuel and enriching uranium — technologies that could be used to make weapons. Now, nearly 40 years after the agreement was signed, South Korea wants Washington to lift that ban. The U.S. refuses to do so. Washington and Seoul were supposed to come up with a new deal this spring before the original agreement expires in March 2014. They haven’t done so, but to prevent a hiatus in nuclear trade the two decided to extend the current agreement for two years and hold additional negotiations every three months until the new expiry date. “Because our cooperation is increasingly broad and deep, there are several complex technical issues that will take some additional time and effort to resolve,” said the U.S. State Department in a statement. The stopgap extension helps avoid potential awkwardness between Park and Obama at their first summit, but it ultimately underscores the clash between Seoul’s goals to expand its nuclear-energy industry and Washington’s efforts to contain the spread of nuclear technologies that could be used to produce weapons.

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Washington’s argument is that if South Korea has enrichment and reprocessing rights, then other countries that are trying to sign nuclear-cooperation agreements with the U.S. will also ask for the same rights and undermine nonproliferation efforts. That line of thinking does not go down well in South Korea, which considers itself a special ally of Washington. “It’s an issue of mistrust,” says Hahm Chai-bong, the president of the Asan Institute for Policy Studies in Seoul. “To simply tell us right now that we don’t have the right to do reprocessing and enrichment because we might be like the North Koreans — that’s just unfair given our relationship and our standing within the global community.”

South Korea’s latest push for securing enrichment and reprocessing technologies has coincided with North Korea’s open threats of war, but many say this is merely a coincidence and that South Korea has no real interest in an expensive nuclear arsenal. The more pressing motivation is commercial: nuclear energy is big business in South Korea, where 23 reactors supply about 40% of the country’s electricity. South Korea plans to generate almost 60% of its electricity from nuclear energy by 2030 and is also building reactors in the United Arab Emirates. As an emerging nuclear-energy leader, it has ambitions to export up to 80 reactors worth more than $400 billion in the next 20 years. To become a more competitive nuclear exporter like France and Russia, South Korea needs the ability to provide nuclear fuel to its customers abroad, goes the argument. And because the nation is running out of space to store nuclear waste, it needs permission to reprocess spent fuel, the South Korean government says.

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U.S. and South Korean negotiators are scheduled to meet again in June, but analysts expect no immediate breakthrough in the talks. “A fair agreement will be one that recognizes South Korea’s emerging role by allowing it access to the technologies that it needs, such as proliferation-resistant used-fuel-management technology, while maintaining tighter controls on technologies such as enrichment, which the U.S. correctly understands as carrying a higher proliferation risk,” wrote Jack Spencer, a senior research fellow in nuclear energy at the Washington, D.C.–based Heritage Foundation. Seoul says one possible solution for breaking the deadlock is pyroprocessing technology. Unlike conventional reprocessing, which produces plutonium (the primary ingredient for building bombs), some scientists believe pyroprocessing leaves separated plutonium mixed with other elements, making it less suitable for nuclear weapons. Experts, however, have yet to reach a consensus that pyroprocessing is more proliferation-resistant. The U.S. and South Korea signed a 10-year research-and-development agreement in 2011 to experiment with pyroprocessing technology. As more research comes out, both sides might have room for compromise.

In the unlikely event that the deadlock remains permanent, Seoul might try to enrich uranium imported from other countries, which is not banned under the current agreement. But taking that path could seriously strain the alliance. For now, South Korea appears set on gaining Washington’s seal of approval. “We have a proven record of having been the best user of nuclear power for peaceful uses — that’s the way we should continue to use it,” explains Hahm. “We’ll see how convinced the Americans are.” It is a sentiment that South Korea’s President will certainly be gauging in Washington.

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