Maybe it's about the ability to build the reactor vessel itself smaller, more like 'common of the shelf', utilizing shipyards, or their supply chains. I think

Maybe it's about the ability to build the reactor vessel itself smaller, more like 'common of the shelf', utilizing shipyards, or their supply chains. I think I've read something about that being a choke point in the way of envisioned mass production. The capacity to build large reactor vessels en masse isn't there, and probably won't be, for economic reasons.