Small Reactor
| Small Reactor | |
|---|---|
| |
| Category: | Power |
| Function: | generates power |
| Fits small grid | |
| Mass: | 278.0 kg |
| PCU: | 25 |
| Size: | 1x1x1 |
| Time to Build: | 20 sec |
| Fits large grid | |
| Mass: | 4793.0 kg |
| PCU: | 25 |
| Size: | 1x1x1 |
| Time to Build: | 40 sec |
| Data Controls: | [edit] [purge] (?) |
The 
Small Reactor is a power production block in Space Engineers.
The 
Small Warfare Reactor is a visual variant with the same functionality and same recipe; you need the Warfare 2 Pack DLC to build it.
Usage
Use the Small Reactor to generate power from uranium. The reactor has no settings other than on or off.
Comparison
The 
Large Reactor is about 1.3 times more efficient (MW/kg) on large ships than this Small Reactor.
On a small ship, a Large Reactor produces about 1.6 times more power per mass than a Small Reactor.
Inventory
With Realistic settings, the Small Reactor has an inventory with a capacity of 125 L for small ships and 1,000 L for large ships. The inventory only accepts the Uranium Ingots which fuel the reactor. If any of its inventory ports are attached to a powered conveyor system, the reactor will automatically attempt to pull ingots when it runs low.
Power
You must place 
Uranium Ingots into the reactor's inventory for it to generate power in survival mode. In Creative Mode, no Uranium is used up to generate power, but the maximum output stays the same.
Grids draw power from reactors only if the output of renewable power providers (such as Solar Panels, Wind turbines) is not sufficient. This ensures that no Uranium is wasted.
- Max output on a large-grid ship or station: 15 MW
- Max output on a small-grid ship: 0.500 MW
Troubleshooting
If the Small Reactor does not produce any power, first make sure its inventory contains (or is conveyored to an inventory containing) Uranium Ingots.
Despite being a power producing block, the Small Reactor depends on the conveyor system to pull fuel. A completely "dead" ship will require some other temporary source of power (e.g. a temporary solar panel) to jump-start the conveyor systems. Or at least you need direct access to one reactor to feed it manually with uranium ingots.
Construction
If progression is enabled, build a 
Basic Refinery first to unlock it.
Small Reactors have one conveyor port and they have a mount point only on that one side. They are not airtight.
You can build Small Reactors on large and small grids. Both are 1x1x1 blocks in size:
- Small Reactors for large-grid ships measure 2.5m x 2.5m x 2.5m
- Small Reactors for small-grid ships measure 0.5m x 0.5m x 0.5m
A Large Reactor is a different block from a Small Reactor on a large ship.
The Small Reactor is 1/27th the size of the Large Reactor (1x1x1 instead of 3x3x3).
Recipe
| Small Reactor | ||||
|---|---|---|---|---|
| Component | Large Ship/Station Required | Large Ship/Station Optional | Small Ship Required | Small Ship Optional |
 Steel Plate | 50 | 30 | 1 | 2 |
 Reactor Comp. | 100 | — | 3 | — |
 Motor | 6 | — | 1 | — |
 Metal Grid | 4 | — | 2 | — |
 Large Steel Tube | 8 | — | 1 | — |
 Construction Comp. | 40 | — | 10 | — |
 Computer | 25 | — | 10 | — |
