Main Turbine Flashcards
What are the system trips associated with the main turbine?
MEMBER TORCH ME OE
Manual (2) - P650 & Front Standard
EHC Oil Pump discharge pressure low - 1100 psig (2 out of 3)
MSR high level - 3” (2.5”) below bottom of MSR (10s td)
Bearing oil low pressure - <21 psig
Electrical faults in Generator/Transformers - Generator, Main Xfmr, or UATs
RWL high - 54” (54.5”)
Thrust Bearing wear (proximeter probes) - 35 mils
Overspeed - Primary – 1980 rpm (110%) - Emergency – 1989 rpm (110.5%)
Runback limits (>6466 amps)
< 20,232 amps in 2 mins (total time), and
< 6,466 amps in 3.5 mins (total time)
Condenser low vacuum - 22.3 inches Hg
High vibration (proximeter probes) - 12 mils (need X & Y on the same bearing)
MSOP Discharge Low - < 105 psig (15 sec TD) when above 1300 RPM
Exhaust Hood High Temp - 225°F
Offline ETD trip test
Excessive Acc/Deceleration Trip
What are the auto start features and power supplies for the Motor Suction Pump?
Used when <90% speed
Oil booster ≤ 20psig
Power supply: R23-S003 (600V C
What are the auto start features and power supplies for the Emergency Bearing Oil Pump?
Start: MSOP < 190 psi AND TGOP < 27 psi OR TGOP loss AC
Power Supply:
2R22-S016 via 2R22-S018 (125/250 swgr 2C)
1R22-S016 (125/250 swgr 1A)
What are the auto start features and power supplies for the Lift Pumps?
Start:
U1 – Brg Hdr > 6 psigand 0 RPM on turbine speed sensor
U2 – Brg Hdr > 6 psig and TGOP>20 psi(start ckt armed)
Power supply:
R24-S005 (600V MCC A)
Unit 2 - 2R23-S002 - 600B
Unit 1 - 1R23-S011 - 600AA
What are the start requirements and power supplies for the Turning Gear Motor? What is different if on alternate power supply?
Start (must have all 3):
0 - 1.5 RPM
500 psi lift
25 psi EBOP or TGOP
Power Supply:
R23-S003 (600V C) (Normal)
R23-S011 (600V AA) (Alternate
If on Alt p/s, turning gear will not auto start and engage & cannot be started from MCR.
What are the auto start features and power supplies for the Turning Gear Oil Pump?
Start:
MSOP < 200 psig
Brg Hdr < 25/15 psi
Power supply:
R23-S003 (600V C) (Normal)
R23-S011 (600V AA) (Alternate
What is the power supply for the steam packing exhauster?
R24-S005 (600V MCC “2B/1AA”)
What are some of the reasons to break vacuum in the main condenser and at what RPM?
Condenser vacuum should not be broken until MT <1200 rpm except for emergencies
Fuel element failure High vibration Loss of bearing oil pressure Low steam seal pressure High MSL Rad
What value are the TCVs clamped at during normal operation? When does #4 TCV start to open?
Clamped at 97% open
TCVs #1, 2, and 3 open simultaneously up to 64% open
When #1,2,&3 @ 64% (~90% RTP), #4 TCV begins to open as required by turbine load (modified partial arc admission)
#4 TCV has limits for opening during operation of 40% (59%) – they are capable of full open during testing (or shell warming)
What stage of the turbine does the first stage reheat steam for the MSR tap off of?
Extraction steam from the HP turbine 2nd stage (3rd stage Unit 1)
What are the limitations associated with the Lift pumps? How are they reset?
Do not stop lift pumps 1, 5 or 6
Unit 2 - Do not stop more than 3 lift pumps
Unit 1 - No more than 2 stopped when <900 RPM (if #3 stopped, do not stop any other pump)
UNIT TWO LIFT PUMPS
- If a lift pump has tripped the “armed” or reset pushbutton must be depressed to restart the pump
- The Control Room switch may be placed to run and the lift pumps will run as long as the switch is held in the “on” position
- Operator must be sent to reset the relay (arm) pushbutton locally to keep lift pump running
- Relay panel inside the Unit 2 Turbine enclosure 164 elevation northwest area
How do you manually trip the main turbine?
Both pushbuttons on either P650 or Front Standard must be depressed simultaneously
What is the TRM Regulator spec for the main turbine?
Mode 1 and 2
TLCO
3 of 3 Throttle press transmitters and 3 of 3 processors shall be FUNCTIONAL
OR
2 of 3 Throttle press transmitters and 3 of 3 processors shall be FUNCTIONAL w/ Eng eval and restoration of 3rd transmitter
OR
1 of 3 Throttle press transmitters and 2 of 3 processors shall be FUNCTIONAL w/ reduced COLR per LCO 3.2.2 and 3.2.3
Conditions
A. All three throttle pressure transmitters or two processors nonfunctional
A.1 Rx Mode switch to SHUTDOWN - Immediately
B. TLCO Not Met other than A.
B.1 Meet TLCO - 24 hrs
C Req Action of B Not Met
C.1 Mode 3 -12 hrs
OR
C.2 Plant management to determine an alternate course of action that continues to assure the safe operation of the plant.
-12 hrs
How do you determine if the turbine is in shell warming, chest warming or tied to the grid?
Looking at the Mark VI display, if TCVs are full open - Shell warming
If ISVs are full open - Chest warming
If showing MWE output as opposed to RPM, then it is tied to the grid
What are the vibration limits associated with the main turbine?
Vibration limits:
< 800 RPM 8 Mils
800-1400 RPM 14 Mils (10 Mils for 2 minutes)
≥ 1400 RPM 12 Mils (12 on X and Y will trip)
