The closest hotel to UCD is the Radisson: rather luxurious and rather expensive. It is a 5-10 minute walk to the meeting.
More reasonably priced is the Talbot hotel, which out-of-season is about 100 euro for a twin room, but could be double than in June. It is 10 minutes on a bus or 35 minutes walking to the meeting.
Half-way from UCD into town is the Hampton hotel. It's about 10 minutes on a bus or 40 minutes walking. It's also only a 25 minute walk from the centre of Dublin.
You could also easily stay in any of the hotels in the centre of the city and get buses, which will take 20-30 minutes, out to UCD.
Another option is B&B (Bed and Breakfast). These are private guest houses with a handful of rooms. They are sometimes less expensive than hotels and some tourists enjoy the experience of staying in an Irish family home.