The calculated distance (air line) between Yŏnggwang-ŭp and Sŭngjibaegam is approximately 110 miles respectively 177 kilometers.
By car or train, the actual journey to Sŭngjibaegam is certainly longer, as only the direct route (as the crow flies) between Yŏnggwang-ŭp and Sŭngjibaegam has been calculated here.
Air line (approximately)
177 kilometers
96 nautical miles