Theory.

U1 was shipped through Canada and England and then where to?

Some how it winds up in Iran's little fingers, and they were sending it to NK for helping to design, develope, and test a nuclear weapon.

NK now says it's stopping development on nuke weapons and so on, is this a sign that Iran knew NK was going to get shutdown?

If so, then all the materials that were in NK are most likely back in Iran now.