Exhaust plumes have been repeatedly seen over the North Korean and none have been observed this past winter.  

According to US experts of the North 38, this fact testifies to the "warming" of buildings for the production of the nuclear element, or preparation for this process, UNIAN reports.

It was reported earlier by QHA that the DPRK leader Kim Jong-un said that it is necessary to increase the number and capacity of the country's nuclear arsenal.

Photo: Internet