It includes all load control and protective devices, containment wiring, metering, interlocking and alarms associated with electrical loads for the reactor system. Power for the system normally is supplied by two turbine-generators, each rated at 1,500 kw, 0.8 pf, 450-volts, 3 phase and 60 cycles. For increased reliability, a double bus type arrangement is used. In the event of a bus fault, an automatic transfer of all vital loads to the other bus will occur. During normal operation, a circuit breaker ties the two busses together.
RADIATION MONITORING
The radiation monitoring system of the SAVANNAH keeps a constant check on the intensity of radiation at various points within the reactor system as well as areas remote from the power plant. This system is divided into two areas for this description. They are power-plant monitoring and health physics monitoring. The latter is covered under its own heading.
POWER-PLANT MONITORING
Through keeping track of the radiation level at various points in the reactor system, any abnormalities in operation can be quickly detected and corrected.
A leak in the heat exchangers, for example, would show up on a radiation monitor located in the blowdown line from each of the heat exchangers.
The intermediate cooling system, which includes cooling water from the primary pumps, shield water cooler, containment air cooler, and other components not directly in the primary loop, is monitored at five locations. Leakage of primary loop water into the secondary water is possible only from the pumps and letdown coolers, because of differences in pressure. Consequently, radiation monitors are located downstream from the letdown coolers and in each of the return lines from the pump cooling coils.
The demineralizers are also monitored. When the resin bed is functioning, the flow downstream (effluent) will have negligible radioactivity. Consequently, a monitor signal at this point will indicate when to switch to a new demineralizer. The monitor in the influent (water entering the demineralizer) measures the activity level in the primary loop.
The fission product monitor keeps track of fission product activity in the primary (reactor) system. The monitor consists of a cation and anion column, an amplifier, and an indicating system. This monitor is located in the primary coolant flow system.