North Korea announced that it succeeded in reprocessing about 8,000 spent fuel rods on April 18, just before the trilateral talks in Beijing. What is the fact of North Korea's nuclear development program?

Most experts on nuclear problems suggest that North Korea has finished 'preparation' for nuclear reprocessing, but has not reactivated reprocessing of the spent fuel rods. Korean and US governments also agree with this. For US, with its spy satellites, it's not difficult to discover North Korea's reprocessing movement. The intelligence satellites can easily spot a material called 'krypton-85', produced in the course of reprocessing.

North Korea seems to have prepared nuclear reprocessing. According to US intelligence officials, it was spotted that North Korea carried coals into the Yongbyon nuclear reactor. Last February, there was another report about blinding white smoke from the nuclear reprocessing boiler.
This boiler is for stabilizing the temperature of nitric-acid-solution, used to melt down  the protection that membrane surrounding spent fuel rods. Some U.S. media also reported that transporting spent fuel rods from Yongbyon nuclear facilities to reprocessing facilities was observed last February.