Columbia class
Columbia class is a nuclear-powered submarine operated by United States Navy, powered by S1B. Under construction.
Replacing Ohio, with electric-drive pump-jet propulsion rather than a mechanical gearbox, which is quieter. Every American SSBN since Ohio has run without refuelling, so the reactor's whole life is decided at construction and the fuel enrichment is doing the work a mid-life overhaul would otherwise do.
| Reactor | S1B |
|---|---|
| Reactors per vessel | 1 |
| Thermal output | not disclosed |
| Fuel enrichment | ~93% U-235HEU |
| Refuelling | None. Designed to run the boat's entire service life on one core. |
| Category | submarine |
|---|---|
| Role | SSBN |
| Operator | United States Navy |
| Country | United States |
| Vessels in class | not stated |
| In service from | - |
| Status | Under construction |
Other submarines
| Class | Enrichment | Status |
|---|---|---|
| AUKUS submarines | HEU | Planned |
| Akula class | - | Operating |
| Alfa class | HEU | Retired |
| Arihant class | HEU | Operating |
| Astute class | HEU | Operating |
| Borei class | HALEU | Operating |
| Dreadnought class | HEU | Under construction |
| Han class (Type 091) | - | Operating |
| Le Triomphant class | LEU | Operating |
| Los Angeles class | HEU | Operating |
| Ohio class | HEU | Operating |
| Oscar II class | - | Operating |
| Seawolf class | HEU | Operating |
| Suffren class (Barracuda) | LEU | Operating |
| Type 093 and 094 (Shang and Jin) | LEU | Operating |
| Typhoon class | - | Retired |
| USS Nautilus | HEU | Retired |
| Vanguard class | - | Operating |
| Virginia class | HEU | Operating |
| Xia class (Type 092) | - | Retired |
| Yasen class | HALEU | Operating |
Columbia class in context
It is one of 22 submarine programs on record, 15 of them operating and 4 retired, and one of 11 naval reactor programs from the same country.
Its fuel is recorded as HEU, the same as 10 of the other 15 submarine programs with a stated enrichment class.
Worked out from the entries on this site only, so a figure compares Columbia class with what is recorded here, not with everything that exists. An entry with no value for a measure is left out of that measure's ranking and median.
Sources
- World Nuclear Association, Nuclear-Powered Ships · retrieved 2026-09-07
How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data