Cheap, safe batteries
Oh you sweet ignorant child. Industrial scale battery storage to offset solar for continues power during night time hours is horrifically expensive when you’re talking gigawatt grids, to say nothing of the severe safety hazard they are.
https://ourworldindata.org/land-use-per-energy-source
Nuclear land use is still below all other forms of energy generation when you take the whole lifecycle, from mining to refinement to production and construction, lile I said in my above post.
Most nuclear plants contain all their nuclear waste during their lifetime operation and transport after decommissioning. Yucca mountain was designed as a backup and assumed 30 years to fill if fuel rods were not reprocessed.