The calculated distance (air line) between Yŏnggwang-ŭp and Uiju is approximately 155 miles respectively 249 kilometers.
By car or train, the actual journey to Uiju is certainly longer, as only the direct route (as the crow flies) between Yŏnggwang-ŭp and Uiju has been calculated here.
Air line (approximately)
249 kilometers
135 nautical miles