The calculated distance (air line) between Yŏnggwang-ŭp and Sariwŏn is approximately 138 miles respectively 223 kilometers.
By car or train, the actual journey to Sariwŏn is certainly longer, as only the direct route (as the crow flies) between Yŏnggwang-ŭp and Sariwŏn has been calculated here.
Air line (approximately)
223 kilometers
120 nautical miles