The calculated distance (air line) between Russkiy and Ungsang-nodongjagu is approximately 85 miles respectively 136 kilometers.
By car or train, the actual journey to Ungsang-nodongjagu is certainly longer, as only the direct route (as the crow flies) between Russkiy and Ungsang-nodongjagu has been calculated here.
Air line (approximately)
136 kilometers
73 nautical miles