Going Nuclear troubleshooting: reactors, centrifuges and emergencies
Handbook · Waste · Next: Reference
Start with the actual state and message, then change one cause at a time. Repeated START presses or complete rod withdrawal are not diagnostic methods.
Structure not recognised
| Message | Check |
|---|---|
| Not assembled / Scanning | Request a Controller scan and wait for its result |
| Exactly one Reactor Controller | Extra controllers and connected neighbouring structures |
| bad size / too big | Exterior dimensions and accidentally connected parts |
| shell hole | Close the stated wall position |
| bad edge | Correct casing at edges and corners |
| core in shell | Move fuel/graphite from the wall into the interior |
| interior blocked | Remove the stated foreign block and preserve coolant space |
| channel unsupported | Continuous channel columns resting on the floor |
| no rod / missing drive | Required roof drive above each relevant column |
| no hot leg / cold leg / fuel | Correct nozzle, position and mode |
| No reactor in range | Desk distance, nearest plant and valid structure |
| RBMK foreign / edge | Correct RBMK family and Biological Shield edges |
Use the BWR layer plan. A coordinate in a scan result is more precise than a guess based on appearances.
Fuel production stops
| Symptom | Checks |
|---|---|
| No nitric acid | Heated Mixer, 500 mB water and 2 Gunpowder per recipe |
| Incomplete Yellowcake remains | Full sequence, including second pressing after the Deployer |
| Yellowcake will not dissolve | Heated Mixer and 250 mB acid per item |
| Centrifuges rotate without output | Every stage at least 128 RPM, six or more stages for 3%+, feed and both outputs |
| Cascade stops after working | Full product/tails tank, disconnected shaft or overstress |
| Less fuel than feed | Separation produces a substantial depleted stream; account for both outputs |
See fuel processing for quantities and cascade layout.
Steam, water and rotation faults
| Symptom | Diagnostic path |
|---|---|
| No steam at turbine | Reactor power → Hot Leg → pump direction → Lead Tank → turbine bottom/side |
| Water unexpectedly in steam tank | Condensation, lit Blaze Burner and water outlet |
| Steam present but shaft stopped | Overstress, shaft connection, load and rotor inertia |
| Water inventory falls despite full reserve | Cold Leg mode, fluid identity, pump direction and actual flow |
| Condensate return blocked | Turbine top outlet and condensate-return setting |
| Pressure rises with full steam line | Reduce power; restore turbine intake and fluid flow |
Buffers can temporarily hide faults. Track whether levels rise or fall across several observations rather than checking only whether a tank contains fluid.
Protection messages
| Display | Meaning for diagnosis |
|---|---|
| FLUX HIGH / FLUX RATE | Excessive power or growth; check rod demand and period calculation |
| ROD STOP | Withdrawal held during rapid growth; reduce demand and stabilise |
| FLOW LOW / PRESS LOW | Check supply, internal pump and coolant losses |
| PRESS HIGH | Backpressure, lost steam intake or valve fault |
| OVERTEMP | Heat generation exceeds removal; SCRAM and preserve cooling |
| TURBINE | Check turbine and load path |
| CONTAINMENT | Check pressure/enclosure state while keeping clear |
| MANUAL | Local or remote SCRAM signal |
| xenon dead time | Use restart calculation and allow xenon to decay |
Labels such as SG LEVEL and NO DC also come from the plant model. Their presence alone does not prove that this version needs an undocumented generator or battery block from another mod.
When random incidents are enabled, coolant disturbances, spurious trips and brief valve openings can occur. Distinguish a transient event from an ongoing supply defect. Repeatedly low water is still a supply problem.
Emergency procedure
- Trigger SCRAM, locally or through the prepared Redstone Link frequency.
- Keep water and heat removal available. Do not shut every pump down reflexively.
- Move away and keep other players clear. Check dose and fallout without returning to the core merely to take a reading.
- Do not dismantle hot or filled core components. This can break cooling and release material.
- Plan repairs only after temperature falls, pressure is controlled and the cause is understood.
RBMK SCRAM is delayed and may initially add reactivity. It cannot instantly undo a runaway state. BWR shutdown also leaves decay heat.
After a severe accident
Hydrogen explosions, containment failure, corium, radioactive debris and fallout can persist after destruction of the Controller. Wind can carry contamination beyond the visible ruin. Secure access, use protection and measuring equipment and plan waste collection together with cleanup. A Purification Core does not cool or repair remaining sources.
Local BuildUp snapshot: resonanceCascade is enabled. The configuration
describes rifts and anomalies when a meltdown occurs during a prompt-critical
excursion above four times rated power. This is a special accident condition,
not the normal result of a shutdown.
Waste processing faults
For a dry pool, restore water and feed first. If transfer stops, check decay, direct adjacency and free destination space. Reprocessing additionally needs 64 RPM or more, acid and room in all three outputs. Repository messages are explained in the waste guide.