Nuclear Reactor

Nuclear Reactor
Nuclear Reactor

Nuclear Reactor

Name Nuclear Reactor
Source Mod IndustrialCraft2
Type Generator
Stackable Yes (64)
Tool Wrench

The Nuclear Reactor is a block added by IndustrialCraft2. It is a method of generating EU or alternatively Steam, when enabled in the IC2 config file. Nuclear reactors require a significant investment of Copper and preparation. Up to six Reactor Chambers can be added to increase the capacity, thereby expanding the possibility of making power. Depending on your mod pack and the purpose of the reactor a large reactor is not necessarily better or cheaper than several small ones.

A newly built nuclear reactor is an empty hull. Nuclear Reactor Components have to be placed into the reactor to render it operational.


Before 1.6[edit]

Reactor Chamber

Advanced Circuit
Reactor Chamber

Reactor Chamber

Nuclear Reactor

Since 1.6[edit]

Dense Lead Plate
Reactor Chamber
Dense Lead Plate
Advanced Circuit
Reactor Chamber
Dense Lead Plate
Reactor Chamber
Dense Lead Plate
Nuclear Reactor


Reactor Hull[edit]

The main reactor chamber is formed by the Nuclear Reactor itself as well as any attached Reactor Chambers. This is where heat is transferred if not drawn away by a component. Also referred to as the "reactor" or "core", etc.


Heat is produced by the Uranium Cells in a reactor. Every tick, the cells will produce heat proportional to the number of cells and Neutron Reflectors next to them. Therefore, placing more cells close together will generate more heat, as will Dual and Quad Uranium Cells.

Cool-Down Period[edit]

The amount of time it takes an inactive reactor to return to a hull temperature of 0 by dissipating the excess heat that it has collected.


Not to be confused with EU ticks, the reactor tick occurs every second. Power and heat output are calculated once every reactor tick, or every second.


Pulses are produced by Uranium Cells in an active Nuclear Reactor once per tick, generating heat and energy. Additional pulses may occur per cell if there are additional cells or Neutron Reflectors next to one another, generating more energy and improved efficiency.


A cycle is defined by the amount of time that it takes for one set of new Uranium Cells to deplete inside of a functioning Nuclear Reactor. This is equal to 2 hours 47 minutes and 38 seconds real-time.

Reactor Design[edit]

The arrangement of components in the Nuclear Reactor GUI. Reactor design determines whether a reactor is an effective power generator or an explosion hazard.


Depending on the purpose of the reactor and its operating conditions it falls into a set of pre-defined categories. More information about categorising Nuclear Reactors can be found here.

Setups for Power Generation[edit]

The simplest reactor consists of a single Uranium Cell placed directly next to a Heat Vent. This will produce 5 EU/t when a redstone current is applied to the reactor. The cell and vent must be adjacent horizontally or vertically; if placed on a diagonal, the vent will not cool the cell and the reactor will heat up and explode. In this basic reactor design, the uranium cell produces 4 units of heat per tick. The heat vent will transfer up to 6 units of heat from surrounding components and since the uranium cell produces less than 6 units of heat per tick, it will be effectively cooled by the single heat vent.

While a single uranium cell produces only 5 EU/t, it will produce 1 million EU over its 2 hour 47 minute lifetime. Placing an additional uranium cell in the reactor, next to the first, will quadruple the energy output of the reactor without decreasing the lifetime of the fuel cells, although it will produce more heat. The addition of Dual and Quad Uranium Cells can further increase energy output and efficiency, again at the expense of increased heat.

Setups for Optimal Use[edit]

There are many different setups you can use for the Nuclear Reactor with endless possibilities. If you want the least risk, and safest amount of power follow these steps.

Needed Resources:

Reactor Diagram

Optional :

Once you have the Needed Resources place a dirt block down, then the Nuclear Reactor. This is necessary to place one of the 6 chambers beneath it. Then Place the remaining 5 chambers around the Nuclear Reactor. Then place the 20 Overclocked Heat Vents, Heat Vent, 8 Component Heat Exchangers, Dual Uranium Cell, and the 2 Quad Uranium Cells according to this diagram.

Setups for Breeders[edit]

Breeder reactors are meant to "farm" more fissile material. While a breeder will output some EU, power generation is not the main purpose. The elevated operating temperatures make breeder reactors more dangerous than reactors for power generation.

More information about breeder reactors can be found here.

Risk of Explosion[edit]

Running a nuclear reactor is not without risk. A nuclear reactor will set fire to nearby flammable blocks at 40% hull heat, evaporate surrounding water source blocks at 50%, start damaging players at 75%, melt the terrain - turning it to lava - at 85%, and explode at 100%. Reactor plating added to the interior will increase the maximum hull temperature, postponing these harmful effects. When the nuclear reactor explodes it will produce a blast proportional to the amount of nuclear fuel inside the reactor. Entering the explosion area will inflict poison and hunger debuffs. These effects can be avoided by wearing the Hazmat Suit. A reactor will function only if supplied with a redstone current, such as that provided by a lever. This characteristic may be used in the construction of redstone circuits designed to detect and prevent reactor overheating.

Explosions are entirely predictable and follow a particular pattern. For example, a reactor with 6 chambers and a uranium cell in every slot, surrounded by a 5x5x5 cube of reinforced stone (minus a block beneath), upon overheating, will: explode upwards creating approximately a 4x4x4 cavity in the north east direction, explode downwards 14 blocks in a 7x7 teardrop fashion in the north east direction, as well as 4 cavities on the sides of, at worst, 4x4x5 in each cardinal direction.

In the worst case, such a fully loaded reactor surrounded by 5x5x5 cube of reinforced stone would only be a threat to anything within 14 blocks in the direction of the switch or wire. On any other side, anything within 5 blocks is threatened.

The maximum power of a reactor explosion will be approximately 1.4x the magnitude of a Nuke with default configuration.

External links[edit]

The IndustrialCraft Reactor Planner v3 is a Java web application that simulates the behavior of the IndustrialCraft2 Nuclear Reactor. It provides a means to develop and test reactor designs without the risks of explosion, and provides instant results over what might be possible in a Creative world:

WARNING: The Reactor Planner is sorely out of date with regards to Gregtech; any designs including Thorium or Plutonium are not accurately simulated!