For the nickel summary of this panel check out this blog post from 3%.
Much of the material from this interview in the Beijinger deals with works other than Republic, but there are some interesting insights, like this:
Between a widespread diaspora and the division of North and South, Korean identity is wrought with questions of nation, race, belonging ... how much does this background influence your desire to write, and your choices for the topics of each book?When I was a child, my father was an army officer. My family had to live near the Demilitarized Zone (DMZ), where I was always hearing the North Korean propaganda speeches. That experience made me think a bit about strange themes like border, nation, prohibition, death, belief and so on. Growing up near the DMZ, one of the most dangerous areas in the world, is quite a rare experience. I think my childhood was the most crucial thing for my ability to write novels. Your Republic Is Calling You, my fourth novel, is the story about a forgotten North Korean spy. It is not just a coincidence that I pick this kind of 'borderline' character. He lives half his life in the North and the other half in the South. I have always felt myself standing on that border.A few more nuggets might be gleaned from this KBS interview.