U.S. Under Secretary of State for Arms Control and International Security Ellen Tauscher in a written response to the Senate Foreign Relations Committee said the EU, India and Japan reprocess nuclear fuel within their own territories at present, but she did not think the Obama administration must apply those cases of authorized reprocessing to other countries, including South Korea. She added there was no need for a revision in the Atomic Energy Agreement signed between South Korea and the United States. The comments effectively slap down calls within South Korea to start reprocessing its own spent nuclear fuel.

The U.S. government seems wary of South Korea reprocessing spent nuclear fuel from the standpoint of "peaceful" use of nuclear energy, suspecting that the country over the long-term wants to make its own nuclear weapons. South Korea tried to develop nuclear weapons in the 1970s, but scrapped the plan. Now the issue has re-emerged after North Korea's second nuclear test.

But reprocessing of spent nuclear fuel and nuclear armament are separate issues. South Korea is the world's fifth-largest atomic energy producer, with four nuclear power plants and 20 reactors that account for 40 percent of power generation. Each year, around 700 t of spent fuel is produced from the 20 reactors, which are stored in water tanks at the power plants. Already, the amount of spent fuel stored in such facilities exceeds 10,000 t and will reach maximum capacity in 2016.

Reprocessing would allow 94.4 percent of the spent fuel to be reused, leaving just 5.6 percent to be treated as waste. From South Korea's perspective, the reprocessing of spent fuel is a pressing economic matter.

But there could be problems as well. Japan built the Rokkasho-mura nuclear fuel reprocessing plant in 1992 and expects to spend around W400 trillion (US$1=W1,273) to operate the facility over a 40-year period. Whether or not to build such a facility at such high costs is a matter for South Korea to decide based on economic considerations, but it is not just an economic issue. It is an encroachment on its sovereignty for an atomic energy powerhouse like South Korea to face limitations in its peaceful usage of nuclear energy.

Tauscher said South Korea's ability to reprocess spent nuclear fuel would violate the 1992 Joint Declaration of the Denuclearization of the Korean Peninsula, which stipulated that North and South Korea would "scrap their uranium enrichment and reprocessing facilities." But it is wrong to use North Korea's unilateral violation of a 17-year-old declaration of denuclearization as a basis to block South Korea's right to the peaceful use of nuclear energy. Recently, North Korea not only restarted its reprocessing facilities but also revealed that it is developing the technology to enrich uranium. The issue of denuclearization should be handled through a new agreement that is much more effective and binding than the existing one.

The South Korea-U.S. Atomic Energy Agreement signed during the 1970s expires in 2014. The two sides must begin talks soon on revising the agreement to expand South Korea's peaceful use of nuclear energy. The solution must be based purely on economic considerations.