NuScale's containment vessel is a metal cylinder around the reactor.[1] Each reactor has its own containment vessel. It's just slightly larger than the reactor, like Fukushima and Peach Bottom. Here's a good drawing.[2] No user-serviceable parts inside. The building is not a containment.

[1] https://www.nrc.gov/docs/ML1535/ML15355A411.pdf

[2] https://spectrum.ieee.org/media-library/image.jpg?id=2557419...