Dublin's Runway 34 has only a VOR/DME approach and furthermore the rate of movements with this runway is somewhat less than with 28, I think. Hence it is used only when operational circumstances so dicate, e.g. for weather reasons or when 10/28 is unavailable for any reason. Runway 16, the reciprocal, is used somewhat more often (it has ILS) but again only when wind or other factors require it.