Atomic Anxieties: How Dangerous is North Korea's Nuclear Program?
The death last week of General Jon Pyong-ho, aged 88, chief architect of the North Korean nuclear program, raises the tantalizing question, “where to from here?.” We’ve become accustomed to a North Korean nuclear program that limps rather than runs. Two factors have constrained the program: a shortage of fissile material and a lack of nuclear testing. Deals cut in the 1990s and at the Six Party Talks (SPT) have also slowed proceedings; twice now the small 5MWe gas graphite reactor (the source of all the North’s current stockpile of plutonium) has been mothballed—and subsequently de-mothballed. But with that reactor being restarted last October, and a new 25MWe light water reactor (LWR) coming on-stream, are we about to see a generational shift to a new, more energetic North Korean nuclear program?
The short answer is ‘no’. The longer answer is more complicated. Broadly, fissile material shortages seem likely to hamper the program for some time yet. Estimates vary as to the size of the current North Korean plutonium stockpile. The US Congressional Research Service figure of between 30 and 50kg (enough for five to eight bombs) seems reasonable, but that figure could be lower if the third nuclear test involved a plutonium device rather than a uranium one (something we don’t know). If the 5MWe reactor is now running smoothly again, Pyongyang can use it to produce about one-bomb’s-worth (6kg) of plutonium per year. But the process is slow, beginning with construction of suitable fuel rods for the reactor, irradiation of the fuel in the reactor, removal and cooling of the fuel, and reprocessing to extract the plutonium.
Size matters. Pyongyang’s problem is that the facility is just too small to allow greater production. Had it completed construction of either its 50-MWe reactor or a 200-MWe reactor, both of which it began building some years back but subsequently abandoned, the equations would look much more unsettling. The 50-MWe reactor would have created enough plutonium for ten bombs per year; the 200-MWe reactor enough for 40 bombs per year.
True, Pyongyang might choose to pursue simultaneously a second path to fissile materials—as the U.S. did during the Manhattan Project. If it used its uranium-enrichment facility solely to produce highly-enriched uranium (HEU), it could produce about 40kg per year. The IAEA defines 25kg of HEU as a “significant” quantity, so let’s say that 40kg equals a capability to make one and a half bombs. But the enrichment facility must spend some time creating low-enriched uranium-oxide fuel pellets for the new LWR. And each new nuclear test will subtract one bomb’s worth of material from the stockpile.
Won’t the LWR provide an alternate source of plutonium for Pyongyang when it begins operations? Yes. Depending on how it chooses to run the reactor and how often it wants to—or can—refuel it, Pyongyang could use it to produce plutonium. Estimates vary about how much. Charles Ferguson, from the Federation of American Scientists, has recently argued that Pyongyang could extract 30–40 kg of plutonium each year (enough for five to seven bombs) from just that facility. That seems a high figure; others suggest lower ranges. Siegfried Hecker suggests a plutonium figure of 10–15kg per year might be more realistic.
The LWR isn’t an ideal producer of weapons-grade plutonium for Pyongyang. The fuel is in the form of ceramic pellets, each fuel-load requires low-level uranium enrichment (unlike the Magnox fuel being fed into the small reactor) and the plutonium reprocessing facility has previously been set up to reprocess metallic fuel, not ceramic. Some analysts—Hecker for example—argue that the LWR’s inherent proliferation-resistance means the North will probably use the LWR for electricity production rather than plutonium production. Further, the fact the North’s restarted its small reactor suggests it wants to retain its present plutonium path.
Still, the possibility for misuse of the LWR—while low—is sufficiently concerning that getting a handle on the program is becoming more important. Recent developments have certainly not been lost on the South Koreans, who have stated that a freezing of the North Korean program at its current level should be a precondition for any resumption of the SPT. Hecker used to champion a proposal called ‘the three nos’: no more bombs, no better bombs, and no export. If Pyongyang keeps going in its current direction, the first two nos seem unlikely to be satisfied.
What can Australia do? Unfortunately, not much. We don’t control the supply of uranium to North Korea, we can’t influence how Pyongyang uses its nuclear infrastructure, and we can’t shape its decisions about missile and nuclear weapon testing. Our intelligence community might be able to lead an effort to clarify stockpile numbers, which would be valuable but not game changing.