Expect more surprises from the Korean Peninsula.
Estimates for new nuclear materials delivered to the North Korean nuclear weapons program reveal that the country could have enough to build 37 to 48 nuclear devices by 2016. That's the higher end of the estimates, and it's multiples above what experts think the reclusive state has today.
The country is currently projected to only have enough fissile material for an average of a dozen smaller-sized plutonium weapons. Independent non-government experts in the West often give a low end estimate between 6-12, and a high end of 12-23. So far, experts doubt that North Korea has been able to develop a miniaturized nuclear design for a missile warhead.
On August 16, the Institute for Science and International Security, a Washington think-tank focusing on nuclear proliferation, produced estimates detailing different scenarios for growth in North Korea's nuclear program - the upper-end estimates in the figures above.
But where does all the new radioactive material come from?
Sources include the new experimental light-water reactor being built at Yongbyon, the center of the country's nuclear program. In 2007-2008, North Korea shut down an older, smaller reactor at the site which had provided its earlier stock of plutonium. In 2009, the regime announced it would build a new reactor along with requisite uranium enrichment facilities.
While the North says the reactors is for civilian purposes, proliferation experts say that it could be used to produce new fissile material. On August 21, the authoritative IHS Jane's Defense Weekly noted that the construction of the reactor crossed a major threshold, as a 69-foot dome was placed over the main building.
Images from a GeoEye-1 satellite on taken at different stages in March, June, and again on Aug. 6, reveal the large structure being moved into place over the reactor housing.
ISIS claims that consultations with a reactor expert indicated that the new reactor would be completed by the latter half of 2013.
Weapons-grade material could come from other locations as well.
In November of 2010, Sigfreid Hecker, nuclear scientist and former director of the U.S.' Los Alamos National Laboratories, was given an exclusive (but very short) look at North Korea's new uranium enrichment facilities, also located at Yongbyon. He estimated that the plant had some 2,000 centrifuges.
Christina Walrond, an author of the new ISIS report, noted that the size of the Yongbyon centrifuge plant could indicate another hidden, pilot facility elsewhere in the country.
Walrond added however, that there is a "high level of uncertainty" concerning North Korea's nuclear program, due to the nature of the regime's isolation and the secretive nature of its development. Unlike Iran, North Korea allows no visits from the International Atomic Energy Agency, and is not a party of the Nuclear Non-Proliferation Treaty.
North Korea is thought to have tested rudimentary nukes in underground explosions in October of 2006 and April 2009. There are expectations among U.S. experts that the country's new leader Kim Jong-un could endeavor to perform another nuclear test, to offset the failure of an April 2012 rocket test (which North Korea called a satellite launch and U.S., Japan, and South Korea denounced as a ballistic missile test) and add legitimacy to his military credentials.
In a Foreign Policy article critical of the attention international media have given Kim Jong-un, the Korea Chair at the Center for Strategic and International Studies (another Washington think tank), Victor Cha, argued against optimism rooted in expectations that the young Kim will behave like a moderate. While everyone has been enamored with Kim Jong-un's amusement park adventures, young wife, and publicity stunts, Cha says the country has been sliding closer to instability and ruin.
"Kim must prove himself -- be it through another missile launch, a nuclear test, or a military provocation against Seoul," warns Cha.