The calculated distance (air line) between Sŭngho 1-tong and Sinanju is approximately 46 miles respectively 75 kilometers.
By car or train, the actual journey to Sinanju is certainly longer, as only the direct route (as the crow flies) between Sŭngho 1-tong and Sinanju has been calculated here.
Air line (approximately)
75 kilometers
40 nautical miles