It isn't the sunset you should be worried about. In all likely hood, IF (and that is a bloody big if) the PRK has nukes at this point, they'll be big suckers, probably gun type, and almost certainly too big for this platform. Thier best bet would be to use a truck to deliver it.

I have no doubt the current Great Leader's father had a bio weapons program, and that it produced results, but I don't know if they could get the refridgerated RV design that the Russians developed to work, not with thier mass budget and tech level. If they did, then you'd be looking at an airburst of either a inhaled particulate, like anthrax or maybe botulism, or plague with live fleas (the Japanese made it work with artillery and gravity bombs during WWII). While scary, they are managable. An inhaled virus they could have in inventory, but I don't think they can get an RV to work that would keep it alive and be able to distribute it worth beans.

Most likely, if you got a suprise package from the malignant dwarf, it would be chemical. Something heavier than air, with a decent persistancy, pop the package at night and let the cloud sink into an urban area. Most likely a nerve agent, but maybe blister or blood. You'd have a little warning, but how do you evac a metropolitan area?

And honestly, as much as I hate to say it, I think the PRK is one of our bigger threats. I dont' think Mr. Kim is able to understand that if he drops this on the West coast, he could get to have a practical lesson in Einstianian physics. The only thing holding us back that I can think of would be that the Japanese would be in the fallout zone. A few years ago, someone compaired Mr Kim to the Joker from Batman- not the worst desciption, just more so. Even if all it was was sneezing powder (remember, this guy is past clinically insane, expect anything), the chaos would be worth it as a destab attack. He'd find it funny.

Of course, given the quantities they have on hand and the historical lack of reliability of thinks stamped "made in the PRK", I doubt that (a) the TD-2 is going to get very far, and (b) that the test will be with a live load.