Eh ... plasma macrocannon aren't firing plasma warheads, but bursts of plasma. I figure that they get fed more or less directly from the ship's fusion core(s).

Anyways the point I was trying to make by bringing up plasma weapons, is that they're STC technology, and they somehow maintain plasma as plasma in the flask, so it's probably not that big a stretch to say that STC atomics have something in them to keep them viable, or are otherwise not susceptible to radioactive decay, for whatever reason.

I know Plasma Macrocannons are not, but Torpedos are plasma warheads, as are Deathstrike missiles. Plasma based explosives are not uncommon in the Imperium. I was under the understanding that the plasma flask was plasma-fuel flask, not a substance in plasma state in the jar itself. Indeed, the Forge World schematic calls it Hydrogen Fuel.The point being that the Imperium have "nuclear type" weapons as normal warfare.

I'm not saying that the Imperium couldn't have some way of suspending nuclear decay - I'm just noting that there's nothing specific that says they do, and assuming that they do brings us back to square one of "why are atomic's expensive" when they shouldn't be with Imperial technology.

I know Plasma Macrocannons are not, but Torpedos are plasma warheads, as are Deathstrike missiles. Plasma based explosives are not uncommon in the Imperium. I was under the understanding that the plasma flask was plasma-fuel flask, not a substance in plasma state in the jar itself. Indeed, the Forge World schematic calls it Hydrogen Fuel.The point being that the Imperium have "nuclear type" weapons as normal warfare.

I'm not saying that the Imperium couldn't have some way of suspending nuclear decay - I'm just noting that there's nothing specific that says they do, and assuming that they do brings us back to square one of "why are atomic's expensive" when they shouldn't be with Imperial technology.

It's hydrogen fuel, yes, but I'm pretty sure that (nowadays, anyways), it's stored as plasma already. Which is ridiculous.

Well, as for why atomics are expensive, you need someone sufficiently high-ranked in the AdMech to have access to the blueprints, who is also willing to make them, and to make the necessary infrastructure investment in order to make them in the first place. Making atomics is not something that you can let helots or servitors do, either. They're basically hand made by high rankers.

Plus, there's the whole cultural aspect ingrained against nukes. Likely holdovers from one or more of the various collapses and Falls Humanity underwent.

Also, in order to do the kind of damage that they do to ships, they have to be huge . The fusion plant driving torps goes off when they strike, which is, or should be, basically a nuke by our standards. Yet an atomic is significantly more powerful. So, either, they're really big, or they're not really normal nuclear reactions.

You could be right about the plasma, but I've never seen that description. I wouldn't put it past a codex or BL write to invent.

Well, we know Atomics are not huge, as they're fired from the standard macrocannon battery. Which indicates they're smaller than even Plasma Torpedoes, and do more damage than a battery of directed fusion explosions. So I would go with the idea the Atomics are something beyond what we think of a Nuclear Weapons.

Hmm, I phrased that poorly. By "huge", I meant the blast size. The physical weapon isn't necessarily that large, but it has to produce one hell of a blast.

On the flip side, a "standard macrocannon" fires shells that are ridiculously sized. Some descriptions call them the size of hab-blocks, others say individual rounds mass in the kilotons.

Depending on what source you're reading, anyways.

I guess my point is, A battery of projectile weapons firing Atomics do well more damage than a similarly size battery of weapons firing directed fusion reactions.

True, but we already have plasma warheads as a standard weapon, as well as controlled fusion blasts (Melta). Atomics are something a category again higher. It's possible the reaction isn't even nuclear, but something even more esoteric.

...then why call them atomics? It's not just so that 40k can make another Dune reference. And, also, the more esoteric weapons are the standard suite of Exterminatus weapons.

Honestly, I wouldn't put it past being there just for the Dune reference. Atomic just means the warhead is, well, something on the atomic scale. That could be fusion, fission, annihilation, what have you. Atomics have also varied rather dramatically in availability and effectiveness over the fluff, so really, who knows.

To be fair, atomics in real life have varied in effectiveness and availability. A suitcase nuke, tac nuke, strategic nuke, and Tsara Bomba are all nukes.

And, sadly, all have shelf lives.

so we believe in vortex warheads but easy nukes are hard to swallow ?

so we believe in vortex warheads but easy nukes are hard to swallow ?

To be fair, both are pretty dang hard to get!

so we believe in vortex warheads but easy nukes are hard to swallow ?

Actually, I think it's expensive, super effective nukes that are hard to work with.