North claims it’s building light-water nuke reactor

North Korea said it has started building a light-water nuclear reactor at its main nuclear site, a U.S. nuclear expert who visited the North last week told the Japanese media on Saturday.

Siegfried Hecker, former director of the Los Alamos National Laboratory in the United States, said he was told by Pyongyang officials that they were constructing a small experimental light-water reactor, according to Kyodo News agency. He said the construction of the reactor, which could generate 25 to 30 megawatts of electricity, will take several years to complete, Kyodo reported.

Hecker was invited by the North and stayed from Tuesday to Saturday.

Analysts say the claim would suggest an increasing sophistication in the North’s nuclear technology because in the past it was not thought capable of building a light water reactor.

The report follows suspicious construction activity at the Yongbyon nuclear site, as noted by the former U.S. nuclear envoy Charles “Jack” Pritchard. Pritchard said upon returning from a visit to the North from Nov. 2-6 that he saw a new structure being erected in Yongbyon.

The Institute for Science and International Security, a Washington-based think tank, said on its Web site in late September that the North appeared to be constructing two small buildings next to the Yongbyon nuclear reactor. It failed, however, to confirm what the buildings are for. Yongbyon, the North’s main reactor, is located about 60 miles north of Pyongyang.

“The North has been observed to be digging a site for something, but what it’s for remains unknown,” an unidentified intelligence official was quoted as saying by Yonhap News Agency. “We need to investigate further.”

Some analysts, however, say the claim made to Hecker must have some significance considering the role he has played in the past.

When visiting the North in January 2004, Hecker was shown a sample of plutonium extracted from spent nuclear fuel at the Yongbyon facility, signalling that a nuclear test by the North was likely. (Plutonium is material used to make an atom bomb. The North is suspected to have produced plutonium at Yongbyon.)

The North conducted its first nuclear test in October 2006.

Because a light-water reactor mainly uses uranium for its fuel, this would be an expansion of the North’s plutonium-based nuclear program.

Light-water reactors normally use low-enriched uranium, which is of no use to North Korea’s weapons program. Light-water reactors, therefore, are used for energy, which is why the international community promised to build two light-water reactors in return for Pyongyang’s freezing of its nuclear programs in the 1994 Agreed Framework.

The technology to convert low-enriched uranium to highly enriched uranium, which can be used to make a nuclear bomb, is only known by a small number of countries. The North is not known to be among them.

Kim Yong-hyeon, a professor of North Korean studies at Dongguk University, said in an interview with YTN that the North Korean claim is a message to the U.S. that Pyongyang will keep working on its nuclear program unless Washington resumes the six-party denuclearization talks.

President Lee Myung-bak said in an interview with Asahi Shimbun over the weekend that talks can proceed when the North shows it’s serious about giving up its nuclear program.

By Moon Gwang-lip [joe@joongang.co.kr]