South Korea and the United States began their ninth round of talks on Tuesday on whether to allow Seoul to enrich uranium and reprocess spent nuclear fuel, the foreign ministry here said.

The parties, represented by Ambassador Park Ro-byug and U.S. Assistant Secretary of State Thomas Countryman, will try to reach a deal to rewrite a civilian nuclear cooperation accord over the course of two days in South Korea’s central city of Daejeon.

The 1974 treaty had been due to expire this March but was extended for two years, after the two sides failed to narrow their differences in a series of negotiations beginning in August 2010.

Under the pact with Washington, dubbed the “123 agreement,” Seoul agreed to refrain from using technologies to enrich uranium and reprocess spent nuclear fuel, even for peaceful purposes.

But it now wants the ban lifted, citing a need to reduce accumulating waste and secure fuel supplies for growing domestic energy demand and its role as a global nuclear plant exporter.

Washington, however, has rebuffed the demand out of proliferation concerns, particularly in consideration of North Korea’s nuclear weapons capabilities. Reprocessing can yield plutonium for use in atomic bombs.

North Korea carried out nuclear tests in 2006 and 2009 with plutonium obtained by reprocessing spent nuclear fuel, while it is yet to be confirmed if the unruly communist country used uranium in its third and latest detonation last year.

South Korea hopes to adopt so-called pyroprocessing technology, a proliferation-resistant method, which would allow the country to further its civil nuclear energy goals.

But some nonproliferation experts say it is not significantly different from reprocessing, and the resulting plutonium could quickly be turned into weapons-grade material.

“We will strive to make an advanced and mutually-beneficial deal by trying to factor in our circumstances and necessities while sharing the U.S.’ reservations,” said a ministry official familiar with the issue.

Meanwhile, diplomatic sources here said the two sides reached a consensus on adopting an amendment to the treaty on cooperation in nuclear energy.

It came after Seoul suggested an amendment during the previous talks last September to elaborate on how to boost cooperation in the nuclear energy industry.

The amendment is expected to stipulate ways to smoothen the required process in the U.S. for South Korea’s export of key parts for building nuclear power plants and to encourage cooperation in terms of spent fuel reprocessing technologies, according to the sources.

“The two reached a consensus on making the amendment, though more discussions are needed on details,” a source said. (Yonhap News)