North Korea says the facility is aimed at generating electricity. It takes about 8,000 fuel rods to run the reactor. Reprocessing the spent fuel rods after a year of reactor operation could yield about 7 kilograms of plutonium — enough to make at least one nuclear bomb, experts say.
Nuclear bombs can be produced with highly enriched uranium or with plutonium. North Korea is believed to have exploded plutonium devices in its first two nuclear tests, in 2006 and 2009.
In 2010, the North unveiled a long-suspected uranium enrichment program, which would give it another potential route to make bomb fuel. Uranium worries outsiders because the technology needed to make highly enriched uranium bombs is much easier to hide than huge plutonium facilities.
But experts say plutonium is considered better for building small warheads, which North Korea needs if it is going to put them on missiles. Analysts say they don’t believe North Korea currently has mastered such miniaturization technology.
Scientist and nuclear expert Siegfried Hecker has estimated that Pyongyang has 24 to 42 kilograms of plutonium — enough for perhaps four to eight rudimentary bombs similar to the plutonium weapon used on Nagasaki in World War II.
It’s not known whether the North’s latest atomic test, in February, used highly enriched uranium or plutonium stockpiles. South Korea and other countries have so far failed to detect radioactive elements that may have leaked from the test and which could determine what kind of device was used.
“North Korea is dispelling any remaining uncertainties about its intention for developing nuclear arms. It is making it clear that its nuclear arms program is the essence of its national security and that it’s not negotiable,” said Sohn Yong-woo, a professor at the Graduate School of National Defense Strategy of Hannam University in South Korea.
“North Korea is more confident about itself than ever after the third nuclear test,” Sohn said. “That confidence is driving the leadership toward more aggressive nuclear development.”