Abundance in numerical dimension one for terminal threefolds in positive characteristic

Let X be a projective ℚ-factorial terminal threefold over an algebraically closed field of characteristic p > 3. We prove the numerical-dimension-one case of abundance: if K${}_X$ is nef with $\nu (K_X)=1$, then K${}_X$ is semiample and $\kappa (X,K_X)=1$.