Increased Nuclear power means few thousand nuclear plants 1000s of metric tons of nuclear waste generated every year. A 1 giga watt nuclear power plant produces 20-30mton of nuclear waste a year. where the fuck will the world store 20-30000 mton of nuclear waste every year.
Worst case in the same places where it stores the gigatons of coal ash laced with heavy metals, mercury, cobalt and arsenic - in thousands of open pits or pools all across the place.
More realistically, a few big hangars will do until the radioactivity declines in a few dozen years.
One option is really to recycle it so that only waste are the actinides. There is plenty of uranium and plutonium that is inert/useful in the nuclear waste. It reduces the waste amount by several orders of magnitude.
To start, you put it in warehouses. Nuclear is an extremely dense fuel, so you don't need much space. I expect that for the same energy produced, you'll have orders of magnitude less waste than, for example, windmill blades, which also can't be recycled.
The biggest problem is radioactive concrete from old plants, but it isn't highly radioactive.
