Uranium Gives NKorea Second Way to Make Bombs

After repudiating negotiations on dismantling its plutonium-based nuclear program, North Korea admitted this month to having an even more worrying way to make bombs.

FILE - In this Feb. 14, 2008 file photo released by U.S. researchers who visited North Korea,...

FILE - In this Feb. 14, 2008 file photo released by U.S. researchers who visited North Korea, Yongbyon Nuclear Center in North Korea are shown empty pits which contained three uranium ore concentrate dissolver tanks, now removed and stored. After repudiating negotiations on dismantling its plutonium-based nuclear program, North Korea admitted in June 2009 to having an even more worrying way to make bombs. After nearly seven years of adamant denials, North Korea announced it can enrich uranium, a simpler way to build nuclear weapons than using plutonium. (AP Photo/S.S. Hecker, File)

(AP)

Following nearly seven years of adamant denials, North Korea announced it can enrich uranium — a simpler method of building nuclear weapons than reprocessing plutonium. Uranium can be enriched in relatively inconspicuous factories that can better evade spy-satellite detection, and uranium bombs may work without test explosions.

The admission — made in a threatening response to a June 12 U.N. Security Council resolution punishing Pyongyang for an underground plutonium bomb test last month — poses a new challenge to the U.S., China, South Korea, Russia and Japan as they seek to stem the reclusive country's atomic ambitions.

Since 2003, they have focused on persuading the North to disable a nuclear reactor north of Pyongyang, where the communist regime had been laboriously extracting plutonium, not a naturally occurring material, from spent fuel rods.

Natural uranium, on the other hand, is readily available. North Korea has said it has an estimated 26 million tons of natural uranium deposits, of which about four million tons can be economically extracted. The Washington-based Federation of American Scientists also said an estimated 4 million tons is high-quality uranium ore.

That doesn't mean North Korea can make a uranium bomb overnight. The uranium must be highly enriched first, and making enough for a bomb requires operating 1,000 to 3,000 centrifuges for a year, said Lee Choon-geun, an expert at South Korea's state-funded Science and Technology Policy Institute.

But its recent announcement suggests the country has begun heading in that direction.

And once the weapons-grade enriched uranium is in hand, it is "significantly easier" to build a bomb from it than from plutonium, said Ivan Oelrich, vice president of the Federation of American Scientists.