Excluding CANDU, which are the only reactors I know of in operation that can operate and be refueled, however the more popular BWR and PWR can't produce power when they are being re-fueled or maintained. So how is that different from wind as a source? How is asking wind to produce power when the wind is not blowing, not like asking another power source to produce power during it's characteristic outage like being refueled or maintained?
Well, planned maintenance is just that. Planned. That means that you can (and do) make sure that there are other sources of power available to take the load when you perform refuelling or other maintenance on your reactor. Besides refuelling only happens once ever several years (depending on a lot of factors, you can and do run on other schedules), so it's not something you can't plan for.
In Sweden we get ca 50% of our power from nuclear (with the rest from hydroelectric) and I can't remember a single instance where a planned, or unplanned for that matter, nuclear power disruption to operations took down the grid. Wind OTOH we could only manage about 10-15% right now befoer the grid would be in trouble.
(Now, refuelling under during operation is actually something you don't want in a reactor, as it increases the proliferation risks. In order to produce weapons grade plutonium you need to constantly remove the Pu239 before it catches another neutron and becomes Pu240, which you don't want in your bomb as it'll fizzle.)
Now, wind on the other hand is much less stable, varying unpredictably on a shorter than hourly scale. You need serious backing by short run up standby power that can deliver a lot of power and cheaply (i.e. hydroelectric with large dams) to be able to tolerate a lot of wind (or solar) for that matter.
Why is distributing the wind as a source of energy too difficult problem for us to manage? It's an emotive claim? What is the problem that you see?
A main problem of course is cost. Long distance transmission can easily lose 10%-20% (even 50% in poor conditions) of the available power to transmission losses. In order for wind to average out, you need to be able to flexibly move lots of power over long distances (i.e. north one day, south the next), which is not cheap. We need a whole new grid in most places, i.e. massive investments are needed. I seem to remember that an area the size of Sweden, (which is roughly 10% larger than California and similar in shape) could just about be enough for wind availability to even out. But we don't have near the transmission capacity to move that much power that flexibly, and that's given that we already have some seriously beefy transmission lines from the Northern hydro electric power plants and the South, where we all live.
The reason that it "works" for Germany, that is seldom mentioned is that they're very well connected electrically to the rest of the continent, that hasn't had an "Energiewende" and probably won't. France's nuclear power plants get to take up the slack in a big way, and there are many times when German wind has to be dumped onto the market at negative prices, i.e. you get paid just to get rid of it. So while "Germany" works electrically (even though it's expensive), it couldn't do so on its own. Not by a long shot. It only works as long as it's neighbours don't do the same thing, which isn't really sustainable.
Another problem with this is that it increases fossil fuel usage compared to countries like Sweden. The reason is simple. Electricity is three times as expensive to the consumer in Germany as it is here. Hence we heat our houses with electricity (mainly using heat pumps) as that makes economic sense. In Germany you can't do that (anymore) and hence people use some form of fossil fuel, both for heating and cooking (natural gas from Russia mainly).
Now, of course, the so called "smart grid" that is often put as a solution to all this, i.e. a grid whereby you could control consumers rather than just producers, unfortunately can't deliver all that it must. Some load can be time shifted, at least to a certain extent, such as heating, and the holy grail, charging your electric car. But much other load can't be, so what little "smart grids" we've already installed, turns mostly into being able to charge the customers more money for the same service. The alternative, if you had only wind and solar would be to run the grid like your favourite third world country. Sometimes you have power, and other times you don't. Whether you have it now, or not, isn't possible to say or plan for in advance, you'll just have to cross your fingers and hope for the best. That's not a kind of grid that western consumers would accept, I think.
So, no matter which way you turn, you'll always have your arse sticking out your backside, as the Swedish saying goes. These are tricky problems, and not easily solved. There's just too darn much physics involved, that won't react to political proclamations.