The calculated distance (air line) between Ungsang-nodongjagu and Chongjin is approximately 52 miles respectively 84 kilometers.
By car or train, the actual journey to Chongjin is certainly longer, as only the direct route (as the crow flies) between Ungsang-nodongjagu and Chongjin has been calculated here.
Air line (approximately)
84 kilometers
46 nautical miles