Nuclear reactor

Nuclear reactor

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Recipe
8 + 500 + 500 + 500 + 500 → 1
Total raw
4.8k + 500 + 3k + 1k + 1k + 500
Map color
Health	500 650 800 950 1250
Stack size	10
Dimensions	5×5
Energy consumption	40 52 64 76 100 MW (burner)
Heat output	40 52 64 76 100 MW heat
Maximum temperature	1000 °C
Mining time	0.5
Prototype type	reactor
Internal name	nuclear-reactor
Required technologies
Produced by
Valid fuel

The nuclear reactor generates heat by burning uranium fuel cells. The heat can be used in a heat exchanger to produce steam which can be used to generate power. Unlike other forms of power generation, it is load-independent – each fuel cell will always be used completely in 200 seconds, regardless of load or the temperature of the reactor.

Instead of completely consuming the fuel, burning fuel in a nuclear reactor results in used up uranium fuel cells. These used up cells can be reprocessed in a centrifuge to get back some of the uranium used to create the fuel cells.

Nuclear reactors have a heat capacity of 10 MJ/C. Thus, they can buffer 5 GJ of heat energy across their working range of 500°C to 1000°C, and require 4.85 GJ of energy to warm up from 15°C to 500°C when initially placed.

Neighbour bonus

Reactors receive a bonus for adjacent operating reactors, which increases their effective thermal output by 100% per each such link. For example, two reactors operating next to each other will output a total of 160 MW of thermal energy, with each reactor producing 40 MW base and receiving 40 MW of adjacency bonus.

The adjacency condition is that a reactor must connect to another reactor with all 3 heat pipe connections on a side (corners & middle of side, see graphic), and these connections must have zero length, to receive the bonus for that side. This means that:

• reactors must be on neighboring tiles; connecting reactors by the heat pipe entity gives no bonus
• offset connections are possible; however, all 3 tiles on that side of the reactor in question must neighbor some other reactor

Additionally, un-fueled reactors do not confer any bonus.

Double-row layout

The most efficient practical layout is an aligned double row of arbitrary length (number of reactors as needed). For even numbers of reactors, the total output of the array is 160n − 160 MW (where n = total number of reactors, and assuming all are fueled). Splitting the row, while possibly logistically beneficial, reduces total power output by 160 MW per split.

Odd numbers of reactors are inefficient in maximizing the bonus, but, if needed, the odd reactor should be aligned with one of the rows. Offsetting the longer row instead would not gain the extra reactor any bonus, while the reactor on the other end of the same row would lose its bonus as well. Placing the odd reactor between the ends of aligned rows would also lead to one fewer bonus, and also make the design un-tileable.

In any case however, such concerns are unlikely to arise until one has a very large base, as the individual output of reactors is massive, particularly with adjacency bonuses. As an example, a 5×2 reactor grid would produce 1,440 MW (1.44 GW), the equivalent of 1,600 steam engines, or 24,000 solar panels.

Square layout

Theoretically, a perfectly square grid of reactors with no spaces between would provide maximum bonus, as it minimizes the number of reactors with unlinked sides. This setup produces 200n − 160×sqrt(n) MW (where sqrt(n) is the square root of the number of reactors).

However, while the heat pipe links will allow energy flow from reactors within the square, with no room around inner reactors, there will be no way to insert and remove fuel cells except manually (heat pipes are traversable by the player), which makes this setup impractical.

Furthermore, the gains compared to the double-row design are not large. After some calculation, one arrives at the expression for the ratio of the two (double-row design in denominator) as (1.25n − sqrt(n)) ÷ (n − 1) which evaluates to, for example, 1 for 4 reactors, 1.07 for 16 reactors, 1.16 for 100 reactors (considering only numbers that both an equal-length double row and a square can be built from), and so on. In the limit (infinite number of reactors), the ratio approaches 1.25 as the edge corrections become insignificant.

Explosion

If a reactor is destroyed when it is above 900°C, it will explode just like an atomic bomb. This explosion has enough power to destroy other reactors, so one explosion can lead to a chain reaction of exploding reactors. [1]

Steam Storage

A fuel cell burns for 200 seconds regardless of energy consumption. Excess power can be stored in accumulators. However, using steam storage rather than accumulators is much more space efficient. A storage tank can store as much as 48 accumulators. See: Power_production#Storing_steam_in_tanks, Storage tank, Electric_system#Storage

History

• 0.15.0:
  • Introduced

See also

• Power production
• Heat pipe
• Steam turbine
• Comprehensive guide on nuclear power