Hi. I'm sure this sort of reactor was already posted somewhere, but I didn't find the ones that would satisfy me, so I made my own one.



It's a semi-automatic reactor (you need to manually control reactivity, but it will automatically support reaction at stable level), breakable (the only unbreakable part is the wall thing which lets air go through, but not particles), reaction controlled by pressure.

Basic principle: positive reactivity is constantly introduced by a white hole that increases pressure in reactor core. When any neutron reaches a sensor, negative reactivity is introduced into the chamber (created by a black hole). Since neutron flow is directly proportional to reaction speed, correct sensor size and negative reactivity value will result in a balanced nuclear reaction. This reactor uses core from my other one, which was proof of concept.

The reactor is fueled by mixture of uran and plutonium. But you don't need to mix them yourself, uran is also a byproduct of the reactor operation - after the initial pure plutonium load and work in the "pure plutonium" mode the fuel will turn into something useable. It uses salted water for coolant (nominal core temperatures can be between 120C and 160C).

It's adequately challenging to control the thing, I guess I'll post it here on forums if anyone wants to have fun with it.


Here's more explanation, a kind of operating manual:
1) Indicators and controls
+REAC: positive reactivity index
-REAC: negative reactivity index
TOT REAC: total reactivity index (estimated due to uneven distribution of pressure)
CORE: core temperature

+REAC is controlled by adding or removing WHOL element into the control chamber.
-REAC is controlled by adding or removing BHOL element into the control chamber. It's usually kept at constant value (the default setting in the save) of about -12.00 while standby, and about -5.00 when operational.

2) Modes of operation
== Pure plutonium mode: this mode is used for starting up reactor from state with only pure plutonium in it. Positive reactivity (+REAC) must be kept at around 1.50 to 2.00. The reactor will mostly produce neutrons, and it must be assured that negative reactivity is small enough to compensate the reaction.

After the reactor burns out most of the plutonium fuel, what's left will be the operational fuel. End of this mode is usually indicated by reaction halting itself at +REAC index of 2.00.

WARNING: the reactor is very prone to running away. Don't overload the core (see white markers), and don't let reactivity jump up over 2.00.

NOTE: it's possible that small bits of internal core are burned out (metal walls). That's fine, although it usually means positive reactivity is alarmingly high.

NOTE: the reaction will be slow at start. Experiment with positive reactivity to get a feeling of how it controls.

== Normal mode: this mode is possible when uran-to-plutonium ratio is something like at least 5-10%. In this mode it's possible to supply additional fuel by adding plutonium, but never exceeding the white line.

In this mode +REAC must be set to 3.00 - 4.00. The reactor works adequately nice at 3.20, and is increasingly prone to runaway as positive reactivity grows to 4.00 and higher.

If core temperature grows, it is possible to replace coolant water with new one - simply pump out all the hot water, and pump in the cold one. It will bring reactor temperature down to approx 110 C.

3) Nominal limits:
== Pure plutonium mode:
+REAC: 1.50 - 2.00
-REAC: -4.00 - -15.00
TOT REAC: 0.40 - 1.00
CORE: 20C - 70C

== Normal mode:
+REAC: 3.00 - 4.00 (sufficient negative reactivity can allow to bring this up to 4.50 - 5.00)
-REAC: -4.00 - -15.00
TOT REAC: 0.80 - 3.00
CORE: 110C - 160C

== Structural limits
+REAC: 7.00 (at over 7.00 the brick walls will collapse around control chamber)
CORE: 200C - 500C (at 200C coolant starts boiling, at 500C everything melts)

4) Off-nominal situations:
== Reactor runaway: in this reactor this is defined as sudden unexpected increase in positive reactivity. This must be compensated manually! It is fairly dangerous if left unaddressed, and may lead to partial or full core meltdown.

== Partial core overheating: indicated by forming of small amounts of water vapor around the reactor core. Positive reactivity must be brought down to 2.00 - 3.00 if this shall happen, and the coolant must be replaced with cold one.

== Critical core overheating: indicated by increasing amounts of water vapor, sometimes leaving no liquid coolant at all. Reactor must be shut down if this is to happen, and restarted again from cold.

== Core meltdown: initial core meltdown is indicated by heavily increasing neutron activity in the reactor core. If this is to happen, there will be about 2 seconds to SCRAM before meltdown occurs. If meltdown has occurred, it will be kept in the lava pool below the reactor core, and must be cooled down externally.

== Lava pool breach: in case of serious explosion in the reactor core (which can't happen if you follow the operational manual) the molten remains of core and fuel may breach through outter protective shell. Not much you can do if this happened.



Sorry if post is long or something like that, I just thought maybe someone would find fun in this. The operational manual describes boring way to run it - it should be pretty hard to melt it down if you don't overload fuel, and keep to op man. But there are many fun experiments and things to do:
- Running off the same initial load of fuel, which requires to increase reactivity beyond 4.00, up to 6.00
- Put some deuterium in the core. Usually causes a violent explosion.
- Run without coolant
- Run stable at extreme temperatures (300C)
- Use something other than SLTW for coolant

NOTE: it *MIGHT* be nicer when there is no limit for coolant, so water wapor just goes out of the reactor. To do this just remove the "roof". It makes it a bit more convenient to add cold coolant when hot one is still boiling.

@ubuntupokemoninc (View Post)
This one controls pressure as a function of neutron flow. It lowers pressure when neutron flow increases