15,000 North Koreans Working on Nuclear Project, Analysts Say

U.S. intelligence analysts believe that about 15,000 North Koreans are at work on a vast, secret underground nuclear facility, a development administration officials say might represent a decision by North Korea to abandon a 4-year-old agreement to freeze its nuclear weapons program.

Clinton administration officials who have been briefed on the intelligence data describe a large-scale tunneling and digging operation in a mountainside about 25 miles northeast of Yongbyon, a former nuclear research center where North Korea is said to have produced enough plutonium for two nuclear weapons.

Intelligence analysts believe that North Korea is building either a nuclear reactor or a reprocessing plant, which they say would take two to six years to complete. National security officials have reached no conclusions about the project.

U.S. officials gave conflicting accounts of whether the operation violated a 1994 framework agreement between the United States and North Korea in which North Korea pledged to freeze and eventually dismantle its nuclear program in exchange for a U.S. promise of billions of dollars in international aid and help in building two nuclear power plants.

One administration official said the construction violated the agreement, but others said the effort did not technically violate the accord.