It was just a rumour Sealord, there were various claims in old books that the Kunsan could fire nuke and chemical warheads, if the tech to do this is not available in North Korea then fair enough. Still the ability of these artillery pieces to fire chemical weapons which I believe the KPA does have still makes them a serious threat to the South.

Chemical and biological weapons almost certainly, but not nukes. There overall level of threat is actually quite limited due to their relatively short range and slow rate of fire as well as vulnerability to airstrikes once they have fired and revealed their positions. Not to mention the south korean armys NBC gear.