OP is probably asking some variation of why not build them on a canal rather than literally right on the coast, Fukishima-style. Part of the problem is the com

OP is probably asking some variation of why not build them on a canal rather than literally right on the coast, Fukishima-style. Part of the problem is the components are very large and very heavy even for industrial projects and coasts have barges and seaports. Some parts are too heavy even for railroad shipment, so its barge and crane or expensively fabricate on site, or expensively assemble on site. Its quite a logistical headache to build a large nuclear reactor. Yes, submarine scale plants are petite, but GW-class baseline generators have very large and heavy parts. WRT to Fukishima, its probably cheaper and more efficient from an engineering perspective to build a massive seawall than an unblockable long canal. The effort and concrete required to build an unblockable kilometer long canal that would survive a 30m tsunami would probably survive a 100m tsunami if put into a seawall instead. Or more likely, management would only permit a 10m rated seawall (or canal) "because that'll never happen" and we all know how that turned out.