A United States website specializing in North Korea analysis reported that the country appears to be continuing activities at its Yongbyon nuclear complex.

38 North presented the analysis on Friday, citing commercial satellite imagery of the Yongbyon Nuclear Scientific Research Center from May 22.

The website said that the new imagery indicates continued activity at the site’s Radiochemical Laboratory and Thermal Steam Plant.

The coal-fired plant reportedly has remained in continuous operation since early March, although the smoke plume has somewhat diminished on the most recent satellite imagery.

However, 38 North added that no clear evidence has been detected to determine if spent fuel rods have been transferred from the storage facility near the five-megawatt reactor in order to produce plutonium.