There are large dormitories on site to accommodate pilgrims. They are large heated rooms where everyone sleeps on the floor in a similar fashion to a jjimjilbang. Lay visitors can also stay in them, as long as they register their name in the reception, which is located in the same building as the post office. With luck, you'll be talking to someone who speaks English. Inquire locally or give the temple a call at +82-43-420-3544 hopefully in Korean. Most visitors, however, choose to stay in nearby Danyang, which has a much wider range of accommodation.
If you miss the last bus, you can find a collection of yeogwan, yeoinsuk and minbak in the tourist village a few minutes downhill from the bus terminal.