  We prove that every Kirchberg algebra in the UCT class has nuclear dimension
1. We first show that Kirchberg 2-graph algebras with trivial $K_0$ and finite
$K_1$ have nuclear dimension 1 by adapting a technique developed by Winter and
Zacharias for Cuntz algebras. We then prove that every Kirchberg algebra in the
UCT class is a direct limit of 2-graph algebras to obtain our main theorem.
