The North Korean nuclear program began in the early 60 when an atomic energy research complex was established in Yongbyon for at least officially civilian purposes, driven by the "Songun" principle (translatable as explained in first part "First the army". This political concept places the army in a position of superiority over other state organs: it becomes the main element of North Korean society and its government for the very protection of the State, to which it is necessary to allocate all energy and capacity. In the wake of this assumption the first reactor was built, of Soviet supply (IRT-2M), which became operational in the 1965.
Subsequently, North Korea independently built a second, thanks again to Soviet supplies and natural deposits of uranium minerals, mainly made up of high quality uraninite (uranium dioxide), estimated at around 4 million tons, present on its own territory. Thanks to this natural resource and to the decisive help also of the People's Republic of China, in the 80 years the North Korean leadership was able to continue the nuclear weapons program, a fact that gave a strong impulse to the development of missile in the country north of the 38th parallel , since to have a respectable nuclear deterrent it is necessary to have adequate carriers.
The results of this nuclear program to date are uncertain: according to the DIA (Defense Intelligence Agency) at the beginning of the 2005 Pyongyang had 12-15 ordnance, for the CIA there were two or three, while for the Department of Energy they were seven or eight.
Such uncertainty depends on multiple factors such as the production capacity of plutonium, a byproduct of 238 uranium fission in nuclear power plants, as well as the cryptic tests carried out by North Korea from the 2000 years to today. According to North Korean sources, these began successfully in the 2006 when, in the Punggye-yok range in the north of the country, an experimental device of a supposed included power was detonated between the 5 and the 15 Kt. Subsequently the second test took place in the 2009 always at the same polygon and with an estimated power of 2,3 Kton which generated an earthquake of magnitude between 4,7 and 5,3 depending on the detection stations. The power increased with the third test performed in the 2013: this time it is estimated between the 6 and the 16 Kton depending on the sources with a magnitude between the 4,9 and the 5,1.
It is not by chance that there has always been talk of estimates: underground atomic tests - such as those carried out by North Korea in the years indicated above - generate seismic waves comparable to those of a medium-intensity earthquake and through the analysis of these it is possible to trace back to the power of the device used. To do this, two types of waves are generated that are generated by the composition of the main waves generated by an earthquake (P waves and S waves): Rayleigh waves and Love waves (called Lg).
Through logarithmic calculations performed on the seismogram measurements it is possible to establish, with a certain margin of error, the power of the exploded device. In particular the power Y is determined by the formula M = A + B Log Y where A and B are constants that depend on which system of measurement of the magnitude is used (there are several) and M is the measurement of the magnitude given by the P waves , S, Lg measured by the seismogram. The margin of error is given by phenomena of attenuation given by the particular composition of the Earth, which is not homogeneous both in terms of composition and density, hence the uncertainty in the calculation of the power of the weapons.
Manuele Serventi Merlo
(photo: KCNA / web)