Storage is quite a bit more expensive than nuclear, and while the cost is dropping it has a long way to go. At the same time, new nuclear technologies like molten salt reactors could well drop the price of nuclear. For that to be a factor, we'd likely have to get more aggressive with licensing new nuclear technologies; i.e. we'd have to treat climate change with the urgency it deserves.
Here's a Lazard report on levelized cost of storage: https://www.lazard.com/perspective/lcoe2019