The calculated distance (air line) between Sevastopol and Nizhnegorskiy is approximately 83 miles respectively 134 kilometers.
By car or train, the actual journey to Nizhnegorskiy is certainly longer, as only the direct route (as the crow flies) between Sevastopol and Nizhnegorskiy has been calculated here.
Air line (approximately)
134 kilometers
72 nautical miles