Nuclear reactor

A nuclear reactor is an advanced power-generation building that converts nuclear fuel into heat, which is transferred to connected heat exchangers and turbines to produce large amounts of electricity. Reactors are placed on the ground and connect to each other and to heat infrastructure via their heat connection points; properly arranged groups of reactors receive substantial neighbour bonuses that multiply their effective thermal output. Reactors require fuel cells to operate and must be cooled and managed with heat pipes, heat exchangers and steam turbines to convert reactor heat into usable electrical power.

Neighbouring reactors that are directly adjacent and have all three heat connections linking them receive a neighbour bonus that increases each reactor’s effective thermal output by 100% per linked neighbour. For example, two adjacent fueled reactors produce a combined thermal output of 160 MW: each reactor has a 40 MW base output and receives an additional 40 MW from the neighbour bonus. Layout matters: continuous links between reactors are required and splitting an array breaks the bonus across the split.

An efficient and practical layout is an aligned double-row of reactors. For an even-length double-row of n reactors (all fueled and fully linked), total thermal output is 160n − 160 MW. Splitting a continuous row reduces output by 160 MW per split. Odd numbers of reactors in a double-row are less optimal; an odd reactor should be aligned with one of the rows to preserve as many links as possible. A large 5×2 reactor grid, for instance, produces 1,440 MW of thermal power, equivalent to 1,600 steam engines or 24,000 solar panels.

A perfect square grid of reactors (no gaps) theoretically maximizes neighbour links and produces 200n − 160×sqrt(n) MW. In practice, square grids are impractical because inner reactors lack space for automated fuel insertion and removal; players must manually traverse heat pipes to refuel inner reactors. The power gain over the double-row layout is modest for most sizes; the ideal layout depends on logistics and whether automated fuel handling is required.

Reactors are dangerous if not properly managed: if a reactor is destroyed while its temperature exceeds 900°C, it detonates with an atomic-bomb–level explosion that modifies terrain and can trigger chain reactions by destroying adjacent reactors. These explosions are powerful enough to destroy nearby reactors, creating cascading detonations and significant map damage in affected biomes.

Practical notes and considerations:

• Ensure continuous three-connection links between adjacent reactors to obtain full neighbour bonuses; partial links do not grant the bonus.
• Prefer double-row layouts for a balance of maximum usable neighbour bonus and access for fueling and maintenance.
• Provide robust cooling and heat transfer networks (heat pipes and exchangers) sized to accept the reactor array’s combined thermal output; undersized heat removal leads to dangerous temperature rise.
• Automate fuel cell insertion and spent fuel removal where possible; plan reactor placement with access for inserters or chests to avoid manual refueling constraints.
• Keep blast-resistant spacing or defensive measures between separate reactor arrays to prevent a single explosion from triggering a chain reaction across your power network.