While it may not have been on purpose (and probably doesn't really qualify for a proper "nuking"), the United States Airforce have in fact dropped four nukes on Denmark, just 41 years ago.

http://en.wikipedia.org/wiki/1968_Thule_Air_Base_B-52_crash

To quote the article: "The conventional high explosive components of four B28FI model hydrogen bombs detonated on impact, spreading radioactive material over a large area in a similar manner to a dirty bomb, although a nuclear explosion was not triggered. The extreme heat generated as 225,000 pounds of unused aviation fuel burned for the next 5 to 6 hours melted the ice sheet, causing some wreckage and munitions to sink to the ocean floor".

And to make matters even more interesting, only wreckage from three of the four bombs were found.

700 Danish and American people worked on the cleanup project for 9 months, often without adequate protection. A lot of the locals and cleanup crew have subsequently gone to court over alleged radiation poisoning. Oh, and did I mention that the nukes stored on Greenland was a breach of Denmark's nuclear free zone policy, and were stored there without permission?

It's all fun and games when you're the big guy.