This all appears to assume some knowledge of power generation or even their approach.
Edit >> sorry! I read the hn linked page, and then I navigated to the design page. I did not also go to “home”. Perhaps the hn link could be for the home page.
The tale goes that DoD was researching both options during the Cold War? and eventually shut down the Thorium research due to the warfare potential of enriched uranium
It's becoming more popular last 10 years or so, with books being written about it and private companies picking up the development of the technology
Link to design page: https://thorconpower.com/design/
As with any promising new idea for energy production, we'll see what the actual costs are once (if) it enters commercial production. Many concepts that work perfectly in the lab fail to succeed industrially.