SPTA's Flashcards
What are the ENTRY conditions for SPTA’s per Section 1.0 of 40EP-9EO01 (RX Trip)?
REAC TRIP (CEDMCS BUS UNDV) alarming (4A07A) CEA rod bottom lights on Rapid drop in RX Power RX Trip circuit breakers open RPS trip setpoints exceeded
When checking Reactor Power is Dropping, if the RX isn’t tripped, what action is performed?
OPEN BOTH -
NGN-L03 and L10 supply breakers (B01)
THEN direct an Operator to open the RX trip breakers
What must be checked when a DG is running to support PBA/PBB loads?
Spray Pond Pump is running
IF NOT, direct Operator to emergency stop the DG
What are the RCS Inventory acceptance criteria?
PZR Level 10%-65% (trending to 33%-53%)
Check RCS is 24F or more subcooled
Check that both Seal Injection and NC is in-service to all RCP’s
If RCS is < 24F subcooled, what is done?
STOP all RCP’s
What is the RCS Pressure Control acceptance criteria?
PZR Pressure 1837-2285 psia
PZR Pressure trending toward 2225-2275 psia
What are the Core Heat Removal acceptance criteria?
At least 1 RCP operating
Loop Delta T is < 10F
RCS is 24F or more subcooled
How do we determine RCS Heat Removal acceptance criteria?
a)At least 1 SG meets BOTH of the following:
Level is 35% WR or more
FW is restoring or maintaining level 45-60% NR
b) Check Tc 560-570F
c) Check SG Pressure 1140-1200 psia
How do we determine CTMT isolation acceptance criteria?
Check CTMT pressure is less than 2.5 psig
Check BOTH:
- No valid CTMT area rad monitor alarms
- No valid steam plant activity monitor alarms
NOTE: If CTMT pressure is 3 psig or more, then ensure a CIAS is initiated
How do we determine the CTMT Temp and Pressure Control acceptance criteria are met?
a. CTMT temp < 117F
b. CTMT Pressure < 2.5 PSIG
If CTMT pressure is > 8.5 PSIG, what must be performed?
a. Ensure CSAS is actuated
b. >4350 GPM flow from a CS Header
c. Stop all operating RCP’s
d. Isolate RCP CBO
What are the Safety Functions (8)?
a. Reactivity Control
b. Maintenance of Vital Auxiliaries
c. RCS Inventory Control
d. RCS Pressure Control
e. Core Heat Removal
f. RCS Heat Removal
g. CTMT Isolation
h. CTMT Temp and Pressure Control
If 1 or more safety functions didn’t meet acceptance criteria, what does the CRS use?
Diagnostic Actions, to determine implementing procedure (ORP or FRP)
What is required before taking contingency actions?
CRS Concurrence
If a full-strength CEA doesn’t insert, what is performed?
Standard Appendix 103, RCS Makeup/Emergency Boration
During a ‘typical trip’ what should RX Power do?
Immediate drop to ~ 7%
Continue decrease at slower rate, final rate of -1/3 DPM SUR
Neutron power stop decrease in source range
Several minutes after a RX trip, what is SUR doing?
Indication has large fluctuations due to low input signal and circuit noise (may not be useful)
What is checked for CEA position post trip?
At least 2 of available indicators: CEDM Control Panel LEL's CEAPDS Core Mimic Rod Bottom Lights CEAC 1&2 RSPT positions
In doubt, BORATE
How long do we Borate during EOP’s?
Until SDM calculation performed (or ORP directs)
At least 1 Charging Pp hard started
During EOP, how fast are we required to initiate a Boration flowpath?
< 15 minutes (30 if using V164) - TS 3.1.2 (Time Critical)
If L03/L10 need to be opened to de-energize the CEDM MG set power to RTSG’s, how long do we wait to restore power to L03/L10?
5 seconds
Why are the generator output breakers opened AFTER tripping the turbine if manually done?
To prevent turbine overspeed
If Main Generator output breakers are opened TOO QUICKLY, what could occur?
Fast Bus XFER of S01 and S02 can be blocked
If a HIGH PRIORITY trip alarm is present on a DG, does EOP allow a manual start attempt?
Guidance is to NOT attempt a start
U1 is being started up. Power is at 5% when a RX TRIP occurs. What is done with Main Generator output breakers?
Leave closed since MOD is open
Why 10-65% PZR Level Operational Limit in SPTA’s?
10% - Ensures operability (lowest lvl of fluid)
65% - Space for Spray (and surge space)
Do we isolate Seal Bleed-Off to an idle RCP?
NO, RCP CBO would rise to RCS pressure across entire 3 seal set of that RCP
When do we NOT stop the last Charging Pump during SPTA’s and 40DP-9AP06?
When we need Aux Spray
On a loss of RCP Cooling and Seal Injection, what are the consequences of NOT isolating CBO?
If CBO isn’t isolated - may affect seal integrity (excess RCS leakage)
In Hot Standby, how long will RCP seals last on Loss of RCP Cooling and Seal Injection?
20 minutes
On a RX Trip, why is PZR Pressure band set at 1837-2285 PSIA)?
Adequate subcooling and No Primary Safety Valves Lift
Why are RCP’s in T2/L2 configuration after SIAS?
Maintain controlled depressurization
SG1 has 2 RCP’s running post-trip. SG2 has only 1 RCP running. What should be expected?
SG1 transfers more heat
SG1 Pressure is HIGHER and Steams more
SG1 Level DROPS faster with equal feed flow
How is ADEQUATE RCS HEAT REMOVAL maintained?
At least 1 SG available for removing Heat
Why is SG Level band 45-60%NR after RX Trip?
45% ensures SG Tubes are covered
60% prevents overfilling of SG (water in SG piping)
Post Trip, what is preferred source of FW to a SG?
NBA
AFN, AFB then AFA
FWCS in RTO with Natural Circulation equals?
TAVG goes UP as Tc is maintained
Th RISES
RTO Feed at higher rate, Tc LOWERS
Why is Tc kept 560-570F post trip?
1140-1200 PSIA (roughly), ensures FW and SBCS operate and no uncontrolled cooldown, also stays below lifting MSSV’s
If starting AFA manually, what is done before starting the pump?
Ensure both steam admission valves are CLOSED
RESETS the speed control circuit
What is the preferred method to cool the RCS while performing SPTA’s?
MINIMIZE steaming, MAXIMIZE feeding
Minimizes potential offsite dose until SGTR is ruled out
How do we verify that a MSIS actuated?
ESFAS Signal initiated
MSIV, MFIV and BD IV’s are CLOSED
During an ESD, when faulted SG dries out (RCS Temps RISING), lowest Tc is noted and what is determined?
Saturation Pressure for Temps from Steam Tables (Adjust ADV’s on intact SG’s, open to target pressure), stabilizes Tc
Why are we worried about REBOUND if MSIS has actuated?
If Tc not stabilized = a large insurge of COLD WATER to the PZR could occur (delta T) - rapid pressure drop
How do we address CTMT Isolation criteria?
CTMT Pressure <2.5# (if above 3#, CIAS initiate)
No valid CTMT Rad ARM or steam activity
If we lose CR RMS during SPTA’s, what is used?
Available in CR (if inadequate, diagnose from available and pre-trip indications)
