All things Nuclear.

Getting Uranium
First, we've got to get the uranium out of the ground. This means building a Uranium mine. It costs 25 PP to build a Uranium Mine.

One Uranium Mine mines 1 unit of Unrefined Uranium per day, but if you have Strip Mining researched from the tech tree, you get 2 units of Unrefined Uranium per day from that mine. A maximum of four uranium mines can be built.

To be used in a  reactor, the Unrefined Uranium you mine must go into a Diffusion Plant, which costs 20 PP to build.

When 1 unit of Unrefined Uranium goes into a Diffusion plant, 1/5 unit reactor-grade Uranium comes out that can be used in RTGs,  civilian power reactors, or maritime reactors

Of course, if you build a Diffusion Plant and feed five units of Unrefined Uranium into it per day, you'll get a unit of reactor-grade Uranium per day.

Producing weapons-grade uranium requires the reactor-grade uranium to be fed into a centrifuge facility, costing 30PP. Each unit of reactor grade uranium produces 1/5 of a unit of weapons-grade uranium.

Nuclear Submarines and their Derivatives:
Cost of constructing nuclear submarines.

Three main parts:
Missile Capacity
Propulsion
Hull


Missile Capacity:
10PP per Ballistic Missile Vertical Launch System (VLS)
*Not including cost for developing submarine launched ballistic missiles
5PP per Cruise Missile VLS
*Not including cost for developing submarine launched guided missiles

Propulsion
Nuclear Reactors:
Benefits: Remove Mk deployment costs
Reactor costs 20PP, 10 units of Reactor-grade Uranium

Conventional Turbines:
Free

Hull
Depending on Payload:
Ballistic Missiles: 10PP
Cruise Missiles: 5PP
Regular Attack Submarine: 1PP


Nuclear Weapons and their Derivatives:
Cost of building Nuclear Warheads, and their yields.

Kiloton Ranges: 2 Weapons Grade units of Uranium (WGU)
20kt - 40PP
50kt - 50PP
150Kt - 60PP
250Kt - 80PP
300Kt - 90PP

Megaton Ranges: 10 WGU required
1Mt - 80PP
Each additional Mt, add 10PP
Note, larger yield results in larger weight and does not necessarily increase it's effects.

Maintenance costs:
4Mk per Cycle per warhead. However, nuclear warheads that are in space are considered to be sufficiently sealed away from any real source of wear, and as such don't require maintenance.


Launching Nuclear Weapons

Methods of Delivery:
ICBMs
Bombers
Cruise Missiles
SLBMs

A launching silo costs 25 PP, and must have either a launch center or a control bunker to be used.
A silo control bunker costs 10 PP.
Both silos and control bunkers are strong enough to withstand all but a multi-megaton direct hit.
You can also launch your ICBMs from launch pads, but then they are not protected at all.
A silo is small because of how much armour it needs, so a rocket within a silo can only be a maximum of around 1.5 meters. A bit wider than the 1.25 meter parts, but smaller than the 2.5 meter rockomax parts.