Some older nuclear power plants are been commissioned back into production:

Three Mile Island

"2027 – Nuclear Regulatory Commission to decide whether to issue operating license to Constellation Energy, with the decision expected in May. If granted, Constellation expects to bring the reactor back online later in the year."

https://www.witf.org/2026/07/28/three-mile-island-reactor-re...

Michigan’s Palisades nuclear power plant

https://www.canarymedia.com/articles/nuclear/americas-first-...

Duane Arnold Energy Center in Iowa

https://www.reuters.com/business/energy/nextera-energy-partn...

https://en.wikipedia.org/wiki/Duane_Arnold_Energy_Center#Res...

You don't need to build them. You can just not retire, or unretire one.

Though we really should get better at building nuclear power plants. I'm think more of small ones to power ships though, not land based ones. Ships are one of the few places where oil/coal are used that there are not realistic renewable alternatives.

It can be a little later. Your requirements is like demanding nobody can buy a house unless they have pay they entire amount upfront.