They work since a long time on diversifying their energy strategy. In my opinion the US wouldn't let the Saudis have nukes, I don't even think the US would be interested in a peaceful nuclear program for the Saudis, despite the talks. The Saudis have this part now (and probably even more) covered through their deal with Pakistan.
https://www.sciencedirect.com/science/article/pii/S2211467X2500094X