CVCS Flashcards
CV-459 and 460 are the _______, fail close on loss of IA, auto Close on a ________signal. One valve on each side of the Missile barrier in containment.
Letdown isolation valves
Low pzr level <17% (459 validated pzr level 2, 460 pzr level 1)
The flow capacity of the 3 orifice valves 8149A, B, and C are________. These valves will auto close on a _____ or if cv-8160 I/C isol valve closes for any reason.
45, 75, 75 gpm
low pzr level <17%
CV8160 and CV8152 are fail _____ valves that automatically ______on a ______ isolation signal. One valve on either side of containment.
Close
Close
Phase A
The _____# relief valve is located ________of the orifice valves and relieves to the ______/
600
downstream
PRT
What system provides cooling to the letdown HX?
CC via CC-130A/B which are fail open valves.
Letdown takes suction from the ______ cold leg of the RCS.
C
CV-131 is the ______ and maintains a constant pressure upstream to prevent _______ in the LDHX.
Back pressure control valve
Flashing to steam
The letdown heat exchanger relief valve will lift at _______ and relieves to the ______/
250#
VCT
CV-129, the temperature control valve will bypass the _______
when a high _______ signal is received at ______. This component fails to the ______ position.
Demineralizers
temperature, 133F
VCT
The mixed bed demin has a flow rate limit of ______ and the cation bed flow is limited to ______.
120GPM
75GPM
Max DP across the CVCS filter is ______.
40psid
CV112A fails to the ______position and is normally used to divert some water to the ______.
VCT
HUT
CV8324A charging isol valve must be ______ to open CV-8389A letdown isol valve.
OPEN
Purposes of CVCS
Regulate RCS chemistry
Maintain PZR level
Provide seal water to RCPs
High head ECCS injection
Means to fill and drain RCS
SI 8801A and B inject to _______ and automatically open on a _____signal.
All 4 RCS cold legs; SI
Letdown orifice valves will auto close whenever cv-459 and/or cv-460 close unless they closed due to _______.
Loss of control power
lcv-112A will modulate to divert from _____ to _____ on validated VCT level _____. Also switches to full divert on validated VCT level _____ at ______.
73-95%; channel 1
>= 95%; channel 2
CV-112D and E auto _____ and CV-112B and C auto ______:
- Low VCT level ____ on both validated 1 and 2.
- _________
OPEN from RWST; CLOSE from VCT
5%; SI signal
CV-112 B will not close until ______ is full open.
CV-112C will not close until _______ isfull open.
CV-112D
CV-112E
CV8110 and CV8111 CV pump miniflows will auto ______ on _____ with 2/4 lo-2 _______level at ______.
Reset by resetting SI and SI recirc sump suction.
Close; SI; RWST; 46.7%
CV8114 and CV-8116 (downstream)CV mini flows: Fail open
Auto _____ on _____ with 2/4 WR RCS P<______.
Auto ______on______with 2/4 WR RCS P>______
Close; SI; 1448 psig
Open; SI; 1643 psig
CV8114 and CV 8116 are reset by resetting ____ and depressing ______.
SI; buttons above each valve
CV-182 controls _____ flow, CV-121 controls both ____ and ____ flow.
Charging; Charging and seal injection
CV-8105 and CV-8106 charging header isolations auto close on ______ and are motor operated valves.
SI
CV8100 and CV8112, seal return isolation valves are located ______ of the 150# relief to the PRT and auto close on a ______.
Downstream
Phase A isolation signal
Failure of both VCT channels LT112 and LT 185:
Level controller rejects to manual
-and-
Divert level control is defeated
CVCS Response to SI signal:
- Both CV pumps start
- SI8801A and B open SI to RCS cold legs
- CV-112D and 112E from RWST open
- CV-112B and 112C from VCT close
- CV8105 and 8106 charging header isol close
- CV pumps mini flows:
a. CV 8110 and 8111 close on RWST lo-2 level 46.7%
b. CV8114 and 8116 close on RCS pressure 1448 psig open at 1643psig with mini flows not reset.
CVCS response to phase A
- CV8100 and 8112 close (Seal return)
2. CV8152 and CV8160 close (letdown)
VCT functions (3000 gallons)
- Back pressure for RCP 1 seal
- Introduce H2 and N2 to RCS
- Place of makeup to rCS
- Remove dissolved gases from RCS
- Suction head for the charging pumps
- Surge volume for the RCS
VCT = _____ gallons per percent
19.3
Centrifugal charging pump ratings:
Design - 150 gpm at 2500 psig
Runout- 550 gpm at 600 psig
Shut off head - 2600 psig
Minimum flow - Auto 52 gpm, Manual 0 gpm, Requires 60 gpm/pump to ensure cooling
LT-112 is validated VCT level ______
LT-185 is validated VCT level ______
LT-112 level setpoints_____
LT-185 level setpoints_____
1; 2
LT-112 LT-185
HI-HI 95%/94%reset 95%/94% reset
CV-112A mod 73-95% Full divert >=95%
Hi 70% 70%
Auto MU off 55% None
Auto MU on 37% None
Low level alarm(all modes but AUTO)
Low level 20% 20%
OPEN112D/E
Close112C/B 5% 5%
*also permits reset of 112s if level rising
*requires validated both channels for 112s to operate
Precaution for running two CV pumps in parallel:
When both CV pumps are run in parallel, the stronger pump will deadhead the weaker pump by backseating the pumps discharge check valve. This will burn up the weaker pump within a minute if no mini flow recirc path on weaker pump.
FI-121A will alarm at Hi flow of ______ and low flow of ____
150GPM
52GPM
-or- PK-459 at 0 demand
How does boron dilution protection system work?
Mitigate the consequences of an inadvertent dilution when the reactor is subcritical
Alarm function with multiple inputs
Channel A
Validated VCT level 2 (normally_LT185) >=70%; or
_CV112A not fully closed
Channel B
Validated VCT level 1 (normally _LT112) >=70%; or
Source range counts doubling within 10 minutes
Control switch for CV-112D and E will go close if switch taken to close, but if low level signal present, will ______.
Reopen
CV pump oil description:
Oil pump normally started from remote shutdown panel. No interlock with pump operation.
Lube oil supplies speed increaser and the pump.
Lube oil cooled by SX water.
CV-8110 and CV-8111 are MOVs and power comes from the _____ train of power. Control signals come from _____ train of control power.- Valves close on ____ signal with 2/4 low ______ level of ______.
opposite
opposite
SI; RWST; <= 46.7%
CV-8110 and 8111 Valves CLOSE on SI with 2/4 Lo‑2 RWST level signal (46.7%)
Ensures under accident conditions:
- Necessary flow supplied to RCS
- Contaminated fluid from CNMT sump not recirced to areas where release is possible
- Reset SI signal from SI Recirc Sump Isolation Valve Reset pushbuttons AFTER SI reset
CV8114 and CV8116 fail _____ on loss of DC power. Control signals and power supply come from _____ train.
open; same
CV8114 and CV8116 CLOSE on _____ with 2/4 RCS Pressure ______.
SI; ,1448 psig
CV8114 and 8116 will open when RCS pressure is _____.
To energize solenoids to close these valves, three conditions must be met :
-______
-RCS Pressure 2/4_______
-RCS Pressure 3/4_______
> 1643 psig
SI; <1448 psig; <1643 psig
CV121 charging flow control valve is an _____ operated valve the fails ______. In auto, level signal comes from ______ controller. Internally biased to establish a minimum flow rate of _____. This maintains flow to the ______.
Air; open; the master pzr level controller; 52 gpm; rcp seals
CV-182 charging header pressure control valve throttles flow to the _____ and impacts flow rate to the _____.
RCS; RCP seal injection
CV-8324A/B fail closed on loss of IA and are interlocked with CV8389A/B. The purpose of this interlock is_______.
Charging must be established before letdown so that cooling is available to the RHX.
CV8146 and CV8147 are the A and B loop return lines. These valves fail ______ on loss of IA (whichever one in service).
CV8145 aux spray fails _____.
All three valves are powered from _____ 125VDC
open
closed
non-esf
Seal return isolation valves shall not be opened unless RCS pressure is >100 psig because______
Since VCT pressure can be higher than RCS pressure, seal return isolation valves are NOT opened unless > 100 psig in RCS to prevent back flushing filter debris into RCP seals
Seal water heat exchanger cooled by _____ and can cool water from 3 sources, which are________ and water is cooled to a temp of about 115F. CC is on the _____ side of the HX
RCP #1 seal leakoff ~12 gpm Excess letdown ~20 gpm/hx CCP miniflow 60 gpm per pump, if a CCP is running Water cooled to 115F Shell
LT112 feeds the control board ______ and LT 185 feeds the _____
meter; recorder
Fire protection interface with CV pumps:
Provides alternate cooling for the CV pump Gear Coolers and Lube Oil Coolers
Uses a hose with Quick Disconnects to attach
FP Cooling Mod was added to ensure a charging pump would be capable of providing RCP Seal Injection during a total loss of SX from flooding in the SX pump room
LCO 3.3.9 BDPS Boron dilution protection system
3.3 INSTRUMENTATION
3.3.9 Boron Dilution Protection System (BDPS)
LCO 3.3.9 BDPS shall be OPERABLE with:
a. One or more reactor coolant pump(s) in operation;
b. Each Reactor Coolant System (RCS) loop isolation valve
open; and
c. The BDPS instrumentation in Table 3.3.9-1 OPERABLE.
—————————-NOTE—————————-
The Boron Dilution Alert Alarm may be bypassed in MODE 3
during reactor startup.
————————————————————
APPLICABILITY: MODES 3, 4, and 5.
A PORV is OPERABLE for LTOP when:
An RHR suction relief valve is OPERABLE for LTOP when:
An RCS vent is OPERABLE when open w/an area of _____
Its block valve is open
Its lift setpoint is set as required by the PTLR and has been tested to open at that setpoint
It has power available to it and its control circuits
Its RHR suction isolation valves are open
Its setpoint is < 450 psig and it has been tested to open at the setpoint
> 2.0 in2
RCS PIVs are defined as any ______ normally closed valves in series W/I the RCS pressure boundary which separate the ____ RCS from an attached _____ system
2
HP
LP
PIV leakage SR flow rates
Verify leakage from each RCS PIV is
equivalent to <= 0.5 gpm per nominal inch of
valve size up to a maximum of 5 gpm at an
RCS pressure >= 2215 psig and <= 2255 psig.
TRM boric acid flowpath, modes 4 and 5
1 boron injection flowpath via CVCS OPERABLE and capable of being powered from an OPERABLE emergency power source:
Flowpath via boric acid xfer pump from BAT OPERABLE
Flowpath from RWST is OPERABLE
Boric acid flowpaths , operating, modes 1-3
1 boron injection flowpath via the CVCS from the RWST shall be OPERABLE and either:
1 additional OPERABLE flowpath from the RWST
An OPERABLE flowpath via a boric acid xfer pump from the Boric Acid Storage System
What is maximum letdown flow? and why?
120 GPM to prevent channeling in the mixed bed demin.
What prevents flashing of letdown flow at the letdown orifices?
3 items
Interlock between CV8389A/B and CV8324A/B
Interlock between CV8149A/B/C and CV459/460
CV131 providing backpressure
Why is backpressure maintained on #1 RCP seal?
To ensure adequate flow (~3gph) to the #2 RCP seal./
When would excess letdown be normally used?
Drawing a pressurizer bubble
Plant heatup
Loss of normal letdown
