Plant at 100% power
SM dispatches PEO to locally open the Rx trip and bypass breakers.
Why is it important for the PEO to get the Rx trip breakers open quickly during the ATWS?
opening the breakers is the fastest operator controlled method for adding negative reactivity to the core
The plant is at 100% power. One of two rod drive motor generator sets trips off-line. As a result:
the plant will remain at 100% power
What is/are the power supply(s) to the rod drive motor generator sets?
32B for MG1A
32N for MG1B
Electrically speaking, where are the Rx trip breakers in relation other than the rod drive MG sets?
in series with the rod drive MG set output breakers
What is the normal output voltage of the rod drive MG sets?
260 VAC
The control rod disconnect switch box is physically located in the:
control room behind the EHC cabinet
How many CRDM fans must be running at minimum when the CRDMs are energized?
one
The plant is at power with reactor trip breaker testing in progress.
What would be the primary consequence if a PEO closed both bypass breakers at the same time?
reactor trip
There is a one hour time limit for recovery of a dropped rod.
The reason for this time limit is because extended operation with a dropped rod could result in which of the following?
excessive localized power peaking when the rod is retrieved
The RPS generates an auto trip signal but the “B” train of RPS fails to actuate.
Assuming the “A” train of RPS operates as designed, how will the reactor trip and bypass breakers respond to this event?
trip breaker “A” and bypass breaker “B” receive open signals only
Plant at 100%. Instrument failure results in a Tavg - Tref deviation. RO manipulate control rods to reduce deviation.
RO initiates rod motion, two control bank “D” rods move to “0” steps. DRPI and rod control alarms come in, and alarms for power range flux deviations and RCS temp deviations.
What will be the RO’s next action?
announce that two rods have dropped, recommend reactor trip
How do the individual control rod disconnect switches prevent rod motion?
power to the rod’s lift coil is interrupted
What is the purpose of the rod control system?
position rods within the core to auto control Rx power and RCS temp
Plant at 100% power. PEO dispatched to locally assist with testing of the “B” Rx trip breaker. Why doesn’t the reactor trip when the “B” Rx trip breaker opens?
because the “B” Rx trip bypass breaker has been closed as part of this test
