The calculated distance (air line) between Cheongju-si and Naesŏ is approximately 112 miles respectively 180 kilometers.
By car or train, the actual journey to Naesŏ is certainly longer, as only the direct route (as the crow flies) between Cheongju-si and Naesŏ has been calculated here.
Air line (approximately)
180 kilometers
97 nautical miles