You will see the subsystem codes on drawing numbers as well, but not as consistently. I have a bunch of drawings starting with "SC-48" however I haven't seen mention of an SC subsystem.
Unlike modern equipment, which is completely electronic and digital, the Savannah had pneumatic controls. So a sensor would have a compressed air line going from it to a gauge in the control room, and the pressure indicated the reading. There were also electric and hydraulic controls. The instrument air supply is separate from ship's air, which is utility compressed air.
Provides regulated compressed air for pneumatic control systems. Completely seperate from the normal Ship's Service compressed air system, but they can be tied together in an emergency. I'm not sure what the difference is between CA and AS, CA seems to be the more common term.
The containment vessel was maintained at about 115F using water to air heat exchangers. The cooling water was from the the CW intermediate cooling water system.
CW provides intermediate cooling water (60F to 90F). The water is cooled using a heat exchanger to sea water. The letdown coolers cool primary system water from 508F down to something less than 115F, before the water goes to the purification system (PP).
Valves on lines which penetrate the containment vessel which will automaticly close to isolate the containment vessel in the event of a reactor vessel or primary system failure. One interesting detail is that generally for a loop into and out of the containment there is only a single controlled valve on the output, and a check-valve in the input.
Used only for emergency cooling of the core, never used for shutdown or decay heat removal. The reason why is that there is only a single barrier between the primary system and sea water.
This system will inject hydrogen gas into the buffer seal surge tank (SL-T1), to dissolve hydrogen in the primary coolant. It is maintained at 20 to 40 cc STP/liter. The fire hazard this creates is another reason why the containment vessel is maintained at less than 10 % oxygen (the normal atmosphere is 20% O2).
The lubrication oil is for all of the bearings in the steam plant (PN). The really important ones are the turbines, reduction gear, and the thrust bearing.
The pressure relief valves of all the nuclear systems are connected to this system, which will condense any steam, and collect the effluent.
This is a collection of dedicated plumbing to sample the water in various parts of the plant. The water is sampled regularly, as frequently as every four hours, and tested for dissolved decay products and chlorides (which can cause catastrophic corrosion).
The Buffer Seal system is the system which allows the control rod drive mechanism to move the control rods within the reactor vessel. The reactor vessel is at about 1750 psig and 508 degrees F, it takes a bit more than an O ring to seal around the control rods. The control rod drive also has to work against that pressure.
The SL system is a set of high pressure pumps which take the cleanest PS water immediately after the PP filters, and pumps it into the control rod seals, such that any leaks are either into the reactor vessel, or are clean water out the top. The water flow through the buffer seals also cools the O rings, which are not rated for temperatures above about 350F.
In case of a catastrophic failure of the reactor controls making it impossible to insert the control rods, the soluble poison system can inject boric acid into the primary system, and poison the chain reaction.
The secondary system is the "conventional" steam plant, generating steam in the steam generators, and running the PN systems for propulsion, and turbo-generators for electricity. That steam is in turn used to generate tertiary steam for loads like heating, the laundry, and the steam table in the galley.
Provides compressed air for regular purposes.
A water tank surrounding the reactor vessel, for radiation shielding. The water is cooled using CW water.
Gaseous waste from (for example) the pressurizer is collected, filtered, and then vented out a chimney on the mast.