I'm not as smart as many of you, nor is this something I've looked into deeply. I say that not only to excuse my stupidity, but also to appear modest and hopefully likeable/helpable. And I say that (as well as this) not only to appear honest, but also to begin with a little humor. I've recently been thinking about writing a very silly, but conceivably realistic, sci-fi story which relies on a specific conceit: a city built around a nuclear fusion reactor in the Long Island Sound. The idea is to use the reactor's waste heat to warm a large part of the Sound, mimicking the waters of the Caribbean around several man-made beaches. Is this in any way possible? Is it practical? How could the environmental impact of temperature change be minimized?