Military small reactor designs use fuel enriched to levels higher than what we want to be standard in civillian reactors. Second, military nuclear reactors are expensive as hell, and we wouldn't want to power our society with them.
We build nuclear submarines because operationally they are unsurpassed, there's no alternative, and the operational benefits are worth sky-high costs. When it comes to the grid, we have cheaper, more flexible, and faster to deploy options.
That's quite a comparison given China's governance and environmental record. China will take your land, poison you, imprison you if you protest and suppress any mention of it on social media or in the press. Of course a business can get a lot done in that environment, is that really something to aspire to?
Some level of permitting reform is warranted but I would think hard about whether you want to adopt China's policies.
Given the current geopolitical trajectories we are going to be adopting their policies one way or another.
Similarly the US navy does not have to produce commercially viable nuclear power on an all in cost basis. Different goals, different situation.