Korea is home to a small number of volcanoes but these volcanoes haven't been active for quite a while. The last recorded activity from a volcano located in Korea was in 1903 from Baekdu Mountain considered to be the biggest volcano in Korea. The other volcanoes in Korea are Ch'uga-ryong, Hallasan, and Ulleungdo. 

Since Korea hasn't had an eruption from any of its volcanoes in quite a while there are not many specific regulations currently in place for people to follow. Right now volcano hazards are managed by disaster management, natural hazard planning, and the health and safety regulations. They ensure that people and projects conform to all laws, regulations, rules and guidance, for land-use planning and building along with health and safety. 

Sources: 

https://en.wikipedia.org/wiki/List_of_volcanoes_in_Korea

https://thinkhazard.org/en/report/67-d-p-r-of-korea/VA

https://web.kma.go.kr/eng/weather/current_state/volcano.jsp#:~:text=There%20are%20three%20volcanoes%20in,activity%20being%20recorded%20in%201903.

https://volcano.si.edu/volcanolist_countries.cfm?country=South%20Korea#:~:text=South%20Korea%20has%203%20Holocene%20volcanoes.

https://vajiramias.com/current-affairs/mount-paektu/5da92b191d5def5b868d3a5c/'

https://www.corejeju.com/location/hallasan-mountain/

https://sites.google.com/site/ulleungdofieldguide/home/about-ulleungdo

https://www.volcanodiscovery.com/chuga-ryong.html