alt Hacker Newsits probably my fault for not making myself clear. i mean when the available space is constrained to a specific amount of space that cannot be exceeded.
just picking random numbers:
i have 1 square mile available. a big reactor takes 4 square miles. i cannot fit a big reactor, despite the bigger reactor being more efficient.
well, I don't think that there is a real problem of "1 square mile is available but not 4 square miles" (this is a different sentence than "there is not enough space"). Especially as small reactor also need to be placed very specifically. So even then, it is still possible that the advantage is for big nuclear plant, as they are still more compact per GWh.