The calculated distance (air line) between Sv. Trojica v Slov. Goricah and Krško is approximately 46 miles respectively 75 kilometers.
By car or train, the actual journey to Krško is certainly longer, as only the direct route (as the crow flies) between Sv. Trojica v Slov. Goricah and Krško has been calculated here.
Air line (approximately)
75 kilometers
40 nautical miles