This is happening because everyone else is providing the capital to finish it except the utility.
No utility in the US was willing to invest a dime in it.
Also there is a backlog of requests to bring new capacity into all the ISO's in the Midwest and to the east. (Thanks to the PJM ISO). The only ISO's ready for new connections are in the west.
People should be surprised/excited this is even reaching production. It had a lot of push back from the entrenched utilities and their nuclear partners.
The company awarded the first contracts to manufacture key parts of the Natrium reactor, the first of its kind. On site activities in Kemmerer, Wyoming for the power plant have already started.