Unfortunately there are no arrival facilities at AMS.
However there is a Mercure Hotel within the terminal that offers shower services (for a fee.) It is very conveniently located, up on the mezzanine in the main terminal.
What I do not know, is what "risk" you take by showering while your bags are unloaded. Because the showers are airside, your bags may be picked up before you are done showering, so you might have to go to the service desk to retrieve them. (This is different from many arrival lounges where you pick up your bags first.)