The Multiblock Reactor is the headline feature of Big Reactors. It is a large, complex multi-block structure built from reactor parts. The basic parts are:
Arranging these in a valid design will automatically cause a reactor to assemble; the reactor will visibly change to have a frame, and any attached controllers will light up.
Reactors must be at least 3 blocks in size in each dimension.
This document is up-to-date as of Big Reactors version 0.2.11A.
Building Your First Reactor
To build a very basic reactor, you will need:
- 22x Reactor Casing
- 1x Yellorium Fuel Rod
- 1x Reactor Control Rod
- 1x Reactor Controller
- 1x Reactor Access Port
- 1x Reactor Power Tap
- 4x Yellorium Ingot, for fuel.
First, place a flat, 3-by-3 square of Reactor Casing down as your reactor's base. At the moment, casing is the only thing you can put on the bottom of a reactor. It should look like this:
Next, build the second layer. Atop the first layer, place 4 pieces of casing at the corners, like this:
Next, we'll add our first utility blocks. These are blocks that allow you to interact with the reactor in different ways. We're going to add:
- A Reactor Controller, which provides a control UI to turn your reactor on and off, as well as to see its state.
- A Reactor Power Tap, which allows you to connect any RF-compatible power cable to draw power out of the reactor.
- A Reactor Access Port, which allows you to insert fuel and remove waste from the reactor.
Place these between the casing blocks on the second layer; they need to be on the outside edges of the reactor, like so:
To complete the second layer, we'll fill in the reactor interior and then add casing. Place a Yellorium Fuel Rod in the center of the second layer. Fuel Rods provide space for fuel. Each fuel rod added increases the available space by 4 ingots.
Also, place a block of Reactor Casing in the one empty space left on the second layer. Reactor cannot have any holes. When complete,it should look like this:
Finally, we'll complete the top layer. Place a ring of Reactor Casing around the outside of the layer:
And place your Reactor Control Rod in the center, atop the Yellorium Fuel Rod. A control rod may only be placed atop a column of Fuel Rods, and the column must go all the way from the bottom of the reactor's interior to the top.
When you place the last block, the reactor will assemble, like this:
Now that it's done, you can right-click the Reactor Access Port to insert fuel. Do so, then right-click on the Reactor Controller and press the Activate button. You should see your reactor heat up and begin producing power, which will be stored in the reactor's energy buffer.
A reactor will buffer up to 10 million RF; any further power produced will be lost. To use this power, place any RF-compatible power conduit, such as Redstone Energy Conduit next to the Reactor Power Tap and connect it to your energy grid.
A reactor must be anchored by a sturdy frame. A "frame" is the outline of the reactor, as if it were a wire-frame drawing. The frame can only be built of Reactor Casing.
A reactor must be a rectangular prism (a cube or similar shape). Reactor Casing and Reactor Glass can be used to build any of a reactor's outer surfaces. The top surface may contain Control Rods. The side surfaces can contain any of the other utility blocks, such as Reactor Controllers, Access Ports and so on.
A reactor's interior consists of columns of Fuel Rods, air and acceptable metal blocks or fluids. The allowed metal blocks are iron, gold, and diamond. Acceptable fluids include Water (both source and flowing), and Thermal Expansion's fluids: redstone, glowstone, pyrotheum, cryotheum and ender.
All fuel rods must be placed in columns which reach the entire height of the reactor's interior. Below a column of fuel rods must be a block of Reactor Casing, and atop every column must be a Reactor Control Rod.
All reactors must have at least one control rod (and thus one column of fuel rods) and one controller.
TIP: Right-click on a disassembled reactor with an empty hand to see the first reason why the reactor has not assembled.
When building a larger reactor, it may help to understand how the design of a reactor's interior changes how it performs. The positioning of a reactor's fuel rods, the number of fuel rods, and the contents of any interior space that isn't occupied by fuel rods will all change its performance, sometimes dramatically.
The Flowchart of Doom
The mechanics of a Multiblock Reactor are displayed in this flowchart:
In brief, the more fuel inside a reactor, the more heat, radiation and power it will produce. Higher heats will produce power faster, but will also consume more fuel. This is the basic design choice you have to make when building your reactor: how fast do you want the reactor to produce power? The faster it produces power, in general, the less fuel-efficient it will be.
Heat, Power and Efficiency
Heat inside a reactor is tracked in two places: inside the fuel rods, and in the reactor as a whole. One of the two major mechanics governing how a reactor performs is heat transference from the fuel rods to the reactor environment. Precisely how this works is detailed later.
Power inside a reactor is produced in two ways: directly via reactions in the fuel, and indirectly by converting the environmental reactor heat into power. Assuming there are no penalties or bonuses in effect, each 100mB of fuel inside a reactor generates about 10RF/t of power. Additional energy is generated as heat, which is added to the fuel rod. Assuming an entirely isolated environment, each 100mB of fuel inside a reactor generates about 1.25RF/t worth of power as heat.
As the heat inside a reactor rises, a small penalty is applied to fuel consumption. Below 200C, the penalty is nonexistent. It rises slowly until about 900-1000C, then increases rapidly until 2000C, at which point it levels off, eventually reaching a maximum at 5000C. By the time a reactor is operating at 1000C, the penalty is roughly 10%. By 2000C, it is over 66%.
(TODO: Confirm these penalty numbers.)
To wring maximum efficiency out a reactor, it is, therefore, important to keep heat as low as possible. In 0.2, the only tools for doing this are by upgrading the interior of your reactor with metal or fluid blocks. These improve heat flow, thus keeping fuel rods cooler and running more efficiently.
Heat inside a reactor's fuel rods is a bad thing - it imposes an efficiency penalty, and cannot be used for power generation. A well-performing reactor needs to transfer heat out of its fuel rods into the reactor environment as quickly as possible.
Fuel rods transfer heat out of themselves to the four blocks horizontally around them (north, east, south, west). If two fuel rods are next to one another, they will transfer heat between themselves. Otherwise, the fuel rod will transfer heat to the reactor environment. The rate of transfer is governed by whatever occupies that block.
Generally, air has very poor heat-transfer rates and will result in the slowest rate of heat transfer. Water is considerably better. The metal blocks (iron, gold) and diamond blocks are very good, with performance corresponding directly to rarity (iron worst, diamond best).
Thermal Expansion fluids can also be used and have varying qualities. Pyrotheum and glowstone perform poorly, redstone performs slightly better than iron, cryotheum performs slightly better than gold and ender performs slightly better than diamond.
Radiation and Fertilization
Aside from directly generating power and heat, fuel will also generate radiation. BR radiation is invisible and harmless; it is more of a game concept than a danger, at the moment. The amount of radiation generated is similar to power and heat - it is directly proportional to the amount of fuel in the fuel rods.
This radiation is emitting randomly in one of the cardinal directions from a fuel rod (north/south/east/west) and will travel up to 4 blocks in that direction, or until it is fully absorbed/dissipated.
When first generated, radiation is split between "fast" and "slow" radiation. "Slow" radiation is easily absorbed and will be converted into heat or fertility, depending on what absorbs it. "Fast" radiation must be moderated down to "slow" radiation before it can be used.
Slow radiation that strikes a fuel rod will fertilize that fuel rod; for a short time afterwards, the fertilized rod will produce additional heat, power and radiation. Slow radiation passing through anything else will be partially converted to reactor environment heat. The rate of absorption is determined by the material itself.
As with heat, air absorbs the least radiation, water absorbs more, and the expensive TE fluids absorb yet more. Metal blocks absorb a moderate amount, slightly superior to water.
Note: Due to a bug, all radiation is emitted as 10% fast, 90% slow. This means that moderation is mostly unimportant with 0.2 reactors.
The other factor is the moderation of radiation. Air, again, performs worst. Water performs well, cryotheum performs excellently, and ender performs best. The metals and other fluids perform about on the level of water.
Mechanics in Detail
Fuel Consumption, Heat, And Radiation
Radiation Propagation and Moderation
Frequently Asked Questions
Explosions and Consequences of High Heat
Reactors do not explode as of Big Reactors 0.2. As heat rises, the reactor consumes extra fuel per RF produced; keeping heat low is important for an efficient reactor, but does not pose any danger to the structures around the reactor.
In the future, there is a planned "Meltdown" feature, where reactors will explode if they get extremely hot. This feature will be disabled by default; you will have to turn it on in the config file if you want to play with it.