Korea clinched a newly revised civilian atomic energy accord with the U.S. on Wednesday, paving the way for a more stable supply of nuclear fuel, better management of used rods, related research and future exports of reactors.

The preliminary signing followed four years and seven months of grueling negotiations since their launch in October 2010. The ceremony was in Seoul and led by Park Ro-byug, Korea’s chief negotiator and ambassador for nuclear energy cooperation, and U.S. Ambassador to Seoul Mark Lippert.

The revamped agreement, last amended in 1974, will expire in 20 years, but the two countries have installed options for additional modifications or an early closure. The existing deal was due to expire in March 2014 but extended by two years for further consultations.

The text establishes a legal framework of conditions and controls to govern commercial atomic activities involving U.S.-origin materials or others used in U.S.-origin facilities. It has 21 articles and two separate agreed minutes, each on detailed implementation plans and a high-level joint panel to be set up to oversee the pact on a standing basis.

With Korea’s newly defined foray into the global nuclear market as a reactor exporter, the previously one-sided deal has now become more “equal, reciprocal and mutually beneficial for both sides,” yet will minimize any risks of nuclear proliferation, the two countries say.

“As the existing accord sealed 40 years ago had various components that needed to be improved, the new one contains various progress focusing on three main areas ― spent fuel management, a steady fuel supply and reactor export promotion,” Park said at a news conference after the ceremony.

“While affirming the two countries’ ‘inalienable right’ to the peaceful research, production and use of nuclear energy as members of the Nuclear Nonproliferation Treaty, the document stipulates that there ought not be any breach of sovereignty as they expand cooperation,” the government said in a statement.

Lippert lauded the initial so-called 1-2-3 agreement as “one of the most sophisticated and dynamic peaceful nuclear cooperation” pacts the U.S. has ever negotiated.

While Washington ensures a reliable supply of fuel for 24 reactors here, the allies will be able to pursue Korea’s enrichment of U.S.-origin uranium up to 20 percent if necessary, through the high-level commission.

The panel is to be jointly headed by Seoul’s vice foreign minister and U.S. deputy energy secretary, and operate four working groups on the three major fields and nuclear security.

The accord will also facilitate bilateral cooperation as Seoul explores ways to tackle the pressing issue of spent fuel management. An advisory panel consisting of municipal leaders, scholars and environmental activists has been established to look into various options in partnership with the government, including storage, disposal and reprocessing at home or overseas.

The two countries are conducting a 10-year fuel cycle study to review a technology called pyroprocessing, which Korean experts have floated as a possible solution to handle Korea’s mounting spent fuel inventory, instead of traditional reprocessing capabilities that run against the longstanding U.S. nonproliferation drive. They will decide on the technique’s commercial feasibility and proliferation implication after the study is completed.

The method is known to be less likely to be used for military purposes and thus less prone to proliferation because it leaves separated plutonium mixed with safer fissile materials.

On the research front, Seoul also secured Washington’s long-term advance consent for such activities as post-irradiation examination and electroreduction, as well as for medical studies, using U.S.-origin spent fuel. Scientists here were previously required to seek U.S. approval on a regular basis, about which they had long grumbled due to delays in their work schedule and what they call bureaucratic hassle.

“A research reactor currently being constructed in Busan will help the production of medical isotopes, which we have been importing entirely from other countries for a fortune because they have to be carried by aircraft given their short half-life,” a ministry official said on customary condition of anonymity.

“With the change, some 1.3 million cancer patients will get examinations more easily, the costs plummet from the current 20 million won ($18,500), and the door opens for us to export the isotopes when the generally old overseas reactors retire.”

Long-term consent was also given for the retransfer of U.S.-origin fissile material and equipment to a third country that has nuclear agreements with both countries. The U.S. would speed up the authorization process for imports and exports.

The deal also calls for greater exchanges of technology and information between the two countries’ industries to expedite joint exports of reactors.

In 2009, Korea won a landmark contract to build four reactors in the United Arab Emirates in partnership with U.S.-based Westinghouse Electric Company LLC, becoming the sixth member of the high-barrier league following the U.S., France, Russia, Canada and Japan.

Korea has since grown into the world’s sixth-largest atomic power generator and had no major accidents. Its maiden commercial domestic operation began in 1978.

Its 24 reactors churned out nearly 22,000 megawatts of electricity as of April 21, according to data by the International Atomic Energy Agency, accounting for about 35 percent of the total power needs.

“The United States is pleased that (Korea) has become one of the leading nations in the development of peaceful uses of nuclear energy,” Lippert said.

“The terms of (the proposed agreement) would also strongly reaffirm the two governments’ shared commitment in nonproliferation and nuclear security as the cornerstone of their nuclear cooperation relationship and will thereby enhance the global nuclear nonproliferation regime.”

For the text to come into force, it will undergo a review in Korea by the Ministry of Government Legislation, intra-agency vice-ministerial and Cabinet meetings and presidential authorization.

In the U.S., it is subject to intra-agency and nonproliferation assessments before being delivered to the president for approval. After a formal signing by the two administrations, the accord will be sent to Congress for a 90-day review and, if it does not disapprove, take effect.

By Shin Hyon-hee (heeshin@heraldcorp.com)