> That weight figure (7190 tonnes, not 4000) for ARC is just for the reactor. https://arxiv.org/pdf/1409.3540.pdf https://arxiv.org/pdf/1409.3540.pdf (page 30)

> That weight figure (7190 tonnes, not 4000) for ARC is just for the reactor. https://arxiv.org/pdf/1409.3540.pdf https://arxiv.org/pdf/1409.3540.pdf (page 30) Thanks. As I hadn't seen that paper, I used the Fletcher class destroyer, which was the most numerous class the US built, and it was slightly on the larger side at about 2000 tons; common destroyers were around 1500 tons IIRC. I also assumed, wrongly it seems, that 500 MW was the electrical power. Anyways, if we're really interested in material requirements for various power plant types, one can check e.g. the DOE quadrennial energy review 2015, Table 10.4 on page 390. One can see that fission does pretty well, about an order of magnitude better than wind (and solar being somewhat worse than wind). I would guess fusion wouldn't do as well as fission, but it shouldn't be a huge difference either considering that except the reactor itself it should be pretty similar.