Item — HN Reader

Might a bigger challenge be the power source? If each firing requires 25MW, then 1000 shells would require 25GW, which is equivalent to the output of several large nuclear power stations.

Edit: Apologies, basic mistake, mixed up power with energy. Thanks for correcting.

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> If each firing requires 25Mw, then 1000 shells would require 25Gw

That's not how power works. Power is energy/second, so if one each firing requires 25Mw, firing every round requires 25Mw.

Edit: Although after doing some calculations, firing 1000 shells would require 22 billion joules of energy, which is about the same as the energy released during nuclear fission of three grams of uranium.

How plentiful is Uranium? I'm not a nuclear engineer, so the 3 grams metric isn't meaningful to me -- is that a considerable amount?

3 grams is between about 1/6 and 1/8 once.

Of course, only a small portion of uranium in a reactor core is converted to something else. After that, they replace the fuel as its output drops a bit.

Disclaimer: I don't know enough to check the "grandparent" post's math. I'm assuming the calc is right in that it's the fission energy, and not total destruction of matter E=mc^2 / matter-antimatter style.

Thanks. That helps with my original question - how portable will this be? If it just needs a very small nuclear reactor with a tiny amount of fuel, then they should be able to have a power source "that generates 25 megawatts" and can "fire 10 times a minute through a barrel capable of lasting 1,000 rounds" on a ship. But what about a truck? Having a weapon with a 125 mile range isn't necessarily all that great if it is too big and heavy to get within 125 miles of most of the things you want to shoot at.