Displays the current heat accumulated in the reactor. Heat is essential for producing steam to power turbines, and its generation rate depends on the reactor’s current power level. If heat exceeds the last marker (red color), emergency cooling will activate to reduce excess heat. If the heat bar fills completely, the reactor will critically overheat, causing damage to the building.

Nuclear reactor

Nuclear reactor cannot start if it is not well maintained. Increase maintenance in order to safely start it.

Drag to set the desired power level for the reactor. The selected level determines the heat generated, directly impacting steam production and fuel consumption. All heat must be utilized; excess will accumulate and may eventually cause the reactor to overheat. Basic reactors lack automated power regulation, meaning their heat output remains constant.

Cooling

Cooling is deployed in case the reactor starts to overheat, and that typically happens when water is not supplied fast enough to be converted into steam (or steam output gets stuck). Cooling is not mandatory if you are not using automatic power regulation. However, it is highly recommended to have it as it provides extra protection and helps to avoid any potential overheating. Coolant ports connect directly to the reactor building, not the main heat exchanger.

Nuclear reactor was critically overheated and is shutting down. Depending on severity, this may cause loss of loaded fuel, damage to the building (loss of maintenance), and leak of radiation.

Power level

Thermal reactor that maintains nuclear chain reaction from enriched uranium rods. The reaction releases a large amount of energy utilized for steam generation. This plant can be set up to effectively provide up to {0} MW of electricity when running on full power. Beware that spent fuel is radioactive and can harm the population if not stored in a specialized facility.

Automatic power regulation

The reactor needs to be turned off before upgrading

Enrichment

Overheating will also cause a significant radiation leak in the area.

If enabled, the reactor will adjust its power output automatically based on heat demand. Automation will not exceed the maximum power level set on the slider and cannot drop below the first level (always keeping the reactor running). This system depends on the cooling loop; without it, rapid heat changes could lead to a meltdown. Automated regulation requires computing power to function.

This reactor can enrich extra fuel when supplied with blanket fuel, though blanket fuel isn’t needed for normal operation. You can adjust the breeding ratio to control how much extra fuel is produced, or disable breeding entirely. If the breeding ratio is set to 1, the reactor will produce exactly enough fuel to sustain itself. Even if the enriched fuel buffer fills up, the reactor will keep running and generating heat without interruption.

This reactor is equipped with an advanced safety feature that prevents radiation leaks during an overheat, but its fuel content will be lost.

The heat threshold where emergency cooling activates (if coolant is available). The cooling system will attempt to reduce excess heat to prevent dangerous buildup.

The minimum amount of fuel required for the reactor to function.

The optimal heat level for the reactor based on its current target power. Heat below this level means the reactor is still warming up. Exceeding this level suggests reduced water circulation, causing heat to build up faster than it can be removed.