  We study the one-loop corrections in power spectrum of long gravitational
waves induced from small scale modes in the models of single field inflation
undergoing a phase of ultra-slow-roll (USR). We show that the spectrum of long
tensor perturbations are largely unaffected by the loop corrections from the
short scalar modes. In particular, the spectrum of long tensor perturbations is
insensitive to the sharpness of the transition from the USR phase to the final
slow-roll phase. This is in contrast to the case of scalar power spectrum in
which the loop corrections can be large for a sharp transition while it is
slow-roll suppressed in a mild transition. We study the tensor-scalar-scalar
bispectrum in the squeezed limit and demonstrate that the Maldacena consistency
condition does hold.
