<rich:tabPanel /> does not support any keyboard interactions out of the box. One way to add it is to include the following javascript code:

 

/**
 * WCAG requires keyboard navigation for tabs. This code turns all inactive tabs into links,
 * so the browser starts tabbing over them. 
 * 
 * Author: Val Blant
 */
jQuery(document).ready(function() {
	jQuery("td.rf-tab-hdr-inact").children('span').each(function() {
		var tabName = jQuery(this).html();
		jQuery(this).empty();
		jQuery(this).append("<a href='#' style='text-decoration:none; color: black;' onclick='return false;'>" + tabName + "</a>");
	});
});