Satellite pictures of North Korea's nuclear buildings have been analysed by nuclear scientist Siegfried S. Hecker and North Korea expert Robert Carlin, in an attempt to discern exactly how much progress the country has made in its fission-powered escapades.
Both have personally visited the aforementioned facilities, so if anyone's going to make an educated call, it's them. Turns out, North Korea's done quite a bit, but not as much as the country's official claims would suggest.
The photos, dated between June 2009 and November 2011, provide a staggered depiction of how far North Korea's enrichment facility and light water reactor have come. In that time, the reactor's external components have almost reached completion -- it's essentially ready to have its internals placed inside. However, the speed at which North Korea's reached this point has analysts concerned. From the Bulletin of the Atomic Scientists:
Was the seismic analysis of the reactor site sufficiently rigorous? Did the regulatory authorities have the skills and independence required to license this reactor in such a short time period? And do Yongbyon [the construction site] specialists have sufficient experience with the very demanding materials requirements for the internal reactor components, including the pressure vessel, steam generator, piping and fuel-cladding materials?
The reactor's planned output isn't massive (100MW thermal, 25MW electric, compared to the 4696MW combined output of Fukushima's Dai-ichi reactors), but even a small scale nuclear disaster is a serious matter.
As for the enrichment facility, North Korea declared in September 2009 that it had successfully conducted "experimental uranium enrichment", however, Hecker and Carlin believe this isn't possible, judging by the state of the site. According to the pair, it "must have been achieved at a different facility".
If you'd like to delve deeper into the analysis, be sure to visit the BotAS link below.
Images: Bulletin of the Atomic Scientists.