The calculated distance (air line) between Krasnoyarsk and Zheleznogorsk is approximately 30 miles respectively 49 kilometers.
By car or train, the actual journey to Zheleznogorsk is certainly longer, as only the direct route (as the crow flies) between Krasnoyarsk and Zheleznogorsk has been calculated here.
Air line (approximately)
49 kilometers
26 nautical miles