NIF, remember, is funded by the DoD. It's not a civilian reactor research program: it's a device for testing fusion reactions in the lab now that the Comprehensive Test Ban Treaty means that they're not allowed to test H-bombs out in Nevada.

This is not to say that it isn't fascinating and there won't be spin-off findings of use to the development of civil fusion reactors, but actual reactor research (e.g. JET, ITER, Wendelstein-7X) is all about magnetic containment for protracted periods (tens to thousands of seconds). And ITER, running on tritium and deuterium, is supposed to use 50 MW of heating power to create a plasma of 500 MW (thermal) for periods of 400 to 600 seconds. No need for a 500TW peak power input (actually much, much lower when you look at it in terms of megajoules delivered in a few nanoseconds).