Add mods: technic, moreores, paintings, Nyancat (Pbj_pup). Small fix: sandwiches

mods/technic_plus_beta/technic/doc/generators.md

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+
+power generators
+----------------
+
+### fuel-fired generators ###
+
+The fuel-fired generators are electrical power generators that generate
+power by the combustion of fuel.  Versions of them are available for
+all three voltages (LV, MV, and HV).  These are all capable of burning
+any type of combustible fuel, such as coal.  They are relatively easy
+to build, and so tend to be the first kind of generator used to power
+electrical machines.  In this role they form an intermediate step between
+the directly fuel-fired machines and a more mature electrical network
+powered by means other than fuel combustion.  They are also, by virtue of
+simplicity and controllability, a useful fallback or peak load generator
+for electrical networks that normally use more sophisticated generators.
+
+The MV and HV fuel-fired generators can accept fuel via pneumatic tube,
+from any direction.
+
+Keeping a fuel-fired generator fully fuelled is usually wasteful, because
+it will burn fuel as long as it has any, even if there is no demand for
+the electrical power that it generates.  This is unlike the directly
+fuel-fired machines, which only burn fuel when they have work to do.
+To satisfy intermittent demand without waste, a fuel-fired generator must
+only be given fuel when there is either demand for the energy or at least
+sufficient battery capacity on the network to soak up the excess energy.
+
+The higher-tier fuel-fired generators get much more energy out of a
+fuel item than the lower-tier ones.  The difference is much more than
+is needed to overcome the inefficiency of supply converters, so it is
+worth operating fuel-fired generators at a higher tier than the machines
+being powered.
+
+### solar generators ###
+
+The solar generators are electrical power generators that generate power
+from sunlight.  Versions of them are available for all three voltages
+(LV, MV, and HV).  There are four types in total, two LV and one each
+of MV and HV, forming a sequence of four tiers.  The higher-tier ones
+are each built mainly from three solar generators of the next tier down,
+and their outputs scale in rough accordance, tripling at each tier.
+
+To operate, an arrayed solar generator must be at elevation +1 or above
+and have a transparent block (typically air) immediately above it.
+It will generate power only when the block above is well lit during
+daylight hours.  It will generate more power at higher elevation,
+reaching maximum output at elevation +36 or higher when sunlit.  The small
+solar generator has similar rules with slightly different thresholds.
+These rules are an attempt to ensure that the generator will only operate
+from sunlight, but it is actually possible to fool them to some extent
+with light sources such as meselamps.
+
+### hydro generator ###
+
+The hydro generator is an LV power generator that generates a respectable
+amount of power from the natural motion of water.  To operate, the
+generator must be horizontally adjacent to flowing water.  The power
+produced is dependent on how much flow there is across any or all four
+sides, the most flow of course coming from water that's flowing straight
+down.
+
+### geothermal generator ###
+
+The geothermal generator is an LV power generator that generates a small
+amount of power from the temperature difference between lava and water.
+To operate, the generator must be horizontally adjacent to both lava
+and water.  It doesn't matter whether the liquids consist of source
+blocks or flowing blocks.
+
+Beware that if lava and water blocks are adjacent to each other then the
+lava will be solidified into stone or obsidian.  If the lava adjacent to
+the generator is thus destroyed, the generator will stop producing power.
+Currently, in the default Minetest game, lava is destroyed even if
+it is only diagonally adjacent to water.  Under these circumstances,
+the only way to operate the geothermal generator is with it adjacent
+to one lava block and one water block, which are on opposite sides of
+the generator.  If diagonal adjacency doesn't destroy lava, such as with
+the gloopblocks mod, then it is possible to have more than one lava or
+water block adjacent to the geothermal generator.  This increases the
+generator's output, with the maximum output achieved with two adjacent
+blocks of each liquid.
+
+### wind generator ###
+
+The wind generator is an MV power generator that generates a moderate
+amount of energy from wind.  To operate, the generator must be placed
+atop a column of at least 20 wind mill frame blocks, and must be at
+an elevation of +30 or higher.  It generates more at higher elevation,
+reaching maximum output at elevation +50 or higher.  Its surroundings
+don't otherwise matter; it doesn't actually need to be in open air.
+
+### nuclear generator ###
+
+The nuclear generator (nuclear reactor) is an HV power generator that
+generates a large amount of energy from the controlled fission of
+uranium-235.  It must be fuelled, with uranium fuel rods, but consumes
+the fuel quite slowly in relation to the rate at which it is likely to
+be mined.  The operation of a nuclear reactor poses radiological hazards
+to which some thought must be given.  Economically, the use of nuclear
+power requires a high capital investment, and a secure infrastructure,
+but rewards the investment well.
+
+Nuclear fuel is made from uranium.  Natural uranium doesn't have a
+sufficiently high proportion of U-235, so it must first be enriched
+via centrifuge.  Producing one unit of 3.5%-fissile uranium requires
+the input of five units of 0.7%-fissile (natural) uranium, and produces
+four units of 0.0%-fissile (fully depleted) uranium as a byproduct.
+It takes five ingots of 3.5%-fissile uranium to make each fuel rod, and
+six rods to fuel a reactor.  It thus takes the input of the equivalent
+of 150 ingots of natural uranium, which can be obtained from the mining
+of 75 blocks of uranium ore, to make a full set of reactor fuel.
+
+The nuclear reactor is a large multi-block structure.  Only one block in
+the structure, the reactor core, is of a type that is truly specific to
+the reactor; the rest of the structure consists of blocks that have mainly
+non-nuclear uses.  The reactor core is where all the generator-specific
+action happens: it is where the fuel rods are inserted, and where the
+power cable must connect to draw off the generated power.
+
+The reactor structure consists of concentric layers, each a cubical
+shell, around the core.  Immediately around the core is a layer of water,
+representing the reactor coolant; water blocks may be either source blocks
+or flowing blocks.  Around that is a layer of stainless steel blocks,
+representing the reactor pressure vessel, and around that a layer of
+blast-resistant concrete blocks, representing a containment structure.
+It is customary, though no longer mandatory, to surround this with a
+layer of ordinary concrete blocks.  The mandatory reactor structure
+makes a 7×7×7 cube, and the full customary structure a
+9×9×9 cube.
+
+The layers surrounding the core don't have to be absolutely complete.
+Indeed, if they were complete, it would be impossible to cable the core to
+a power network.  The cable makes it necessary to have at least one block
+missing from each surrounding layer.  The water layer is only permitted
+to have one water block missing of the 26 possible.  The steel layer may
+have up to two blocks missing of the 98 possible, and the blast-resistant
+concrete layer may have up to two blocks missing of the 218 possible.
+Thus it is possible to have not only a cable duct, but also a separate
+inspection hole through the solid layers.  The separate inspection hole
+is of limited use: the cable duct can serve double duty.
+
+Once running, the reactor core is significantly radioactive.  The layers
+of reactor structure provide quite a lot of shielding, but not enough
+to make the reactor safe to be around, in two respects.  Firstly, the
+shortest possible path from the core to a player outside the reactor
+is sufficiently short, and has sufficiently little shielding material,
+that it will damage the player.  This only affects a player who is
+extremely close to the reactor, and close to a face rather than a vertex.
+The customary additional layer of ordinary concrete around the reactor
+adds sufficient distance and shielding to negate this risk, but it can
+also be addressed by just keeping extra distance (a little over two
+meters of air).
+
+The second radiological hazard of a running reactor arises from shine
+paths; that is, specific paths from the core that lack sufficient
+shielding.  The necessary cable duct, if straight, forms a perfect
+shine path, because the cable itself has no radiation shielding effect.
+Any secondary inspection hole also makes a shine path, along which the
+only shielding material is the water of the reactor coolant.  The shine
+path aspect of the cable duct can be ameliorated by adding a kink in the
+cable, but this still yields paths with reduced shielding.  Ultimately,
+shine paths must be managed either with specific shielding outside the
+mandatory structure, or with additional no-go areas.
+
+The radioactivity of an operating reactor core makes starting up a reactor
+hazardous, and can come as a surprise because the non-operating core
+isn't radioactive at all.  The radioactive damage is survivable, but it is
+normally preferable to avoid it by some care around the startup sequence.
+To start up, the reactor must have a full set of fuel inserted, have all
+the mandatory structure around it, and be cabled to a switching station.
+Only the fuel insertion requires direct access to the core, so irradiation
+of the player can be avoided by making one of the other two criteria be
+the last one satisfied.  Completing the cabling to a switching station
+is the easiest to do from a safe distance.
+
+Once running, the reactor will generate 100 kEU/s for a week (168 hours,
+604800 seconds), a total of 6.048 GEU from one set of fuel.  After the
+week is up, it will stop generating and no longer be radioactive.  It can
+then be refuelled to run for another week.  It is not really intended
+to be possible to pause a running reactor, but actually disconnecting
+it from a switching station will have the effect of pausing the week.
+This will probably change in the future.  A paused reactor is still
+radioactive, just not generating electrical power.
+
+A running reactor can't be safely dismantled, and not only because
+dismantling the reactor implies removing the shielding that makes
+it safe to be close to the core.  The mandatory parts of the reactor
+structure are not just mandatory in order to start the reactor; they're
+mandatory in order to keep it intact.  If the structure around the core
+gets damaged, and remains damaged, the core will eventually melt down.
+How long there is before meltdown depends on the extent of the damage;
+if only one mandatory block is missing, meltdown will follow in 100
+seconds.  While the structure of a running reactor is in a damaged state,
+heading towards meltdown, a siren built into the reactor core will sound.
+If the structure is rectified, the siren will signal all-clear.  If the
+siren stops sounding without signalling all-clear, then it was stopped
+by meltdown.
+
+If meltdown is imminent because of damaged reactor structure, digging the
+reactor core is not a way to avert it.  Digging the core of a running
+reactor causes instant meltdown.  The only way to dismantle a reactor
+without causing meltdown is to start by waiting for it to finish the
+week-long burning of its current set of fuel.  Once a reactor is no longer
+operating, it can be dismantled by ordinary means, with no special risks.
+
+Meltdown, if it occurs, destroys the reactor and poses a major
+environmental hazard.  The reactor core melts, becoming a hot, highly
+radioactive liquid known as "corium".  A single meltdown yields a single
+corium source block, where the core used to be.  Corium flows, and the
+flowing corium is very destructive to whatever it comes into contact with.
+Flowing corium also randomly solidifies into a radioactive solid called
+"Chernobylite".  The random solidification and random destruction of
+solid blocks means that the flow of corium is constantly changing.
+This combined with the severe radioactivity makes corium much more
+challenging to deal with than lava.  If a meltdown is left to its own
+devices, it gets worse over time, as the corium works its way through
+the reactor structure and starts to flow over a variety of paths.
+It is best to tackle a meltdown quickly; the priority is to extinguish
+the corium source block, normally by dropping gravel into it.  Only the
+most motivated should attempt to pick up the corium in a bucket.