No, they are not typically complementary. The optimal solutions for powering a grid tend to either be all-nuclear or all-renewable (usually the latter now), depending on cost assumptions. Optimal solutions with a mixture are uncommon.

No, nuclear wants a dispatchable generation source to provide the power. It only makes sense as a complement when the dispatchable generation is expensive to run somehow, if it's cheaper than the nuclear than you should just not bother with nuclear. The two things which complement it are gas turbine generators (cheap to build, dispatchable, expensive fuel), and storage (very expensive to build ATM, needs to buy power when there's excess, but otherwise cheap). Renewables are not this: the energy they produce is cheap but not at all dispatchable (curtailable, yes, but you can't just get more wind blowing on demand). What this means is that sometimes they fail to provide the peak and sometimes they can provide the whole peak and more, which both doesn't provide a reliable grid and eats into the economic justification for nuclear. So, you want to pair them with dispatchable generation to fill in the gaps, which sounds familiar, no? In fact the only difference is with nuclear your gaps are more periodic and there's not such a large range of the gaps.

That's why they don't complement each other: they actually want the same, different thing to complement them: something which can fill in the gaps in the power that they can economically provide. And renewables are a heck of a lot cheaper than nuclear at the moment.