The calculated distance (air line) between Yŏnggwang-ŭp and Ranam is approximately 165 miles respectively 266 kilometers.
By car or train, the actual journey to Ranam is certainly longer, as only the direct route (as the crow flies) between Yŏnggwang-ŭp and Ranam has been calculated here.
Air line (approximately)
266 kilometers
143 nautical miles