Reactor Coolant System Flashcards
Natural circulation indications
-RCS subcooling- acceptable
-SG Pressure- Stable or Decreasing
-RCS hot leg temps- stable or Decreasing
-RCS cold leg temps- At saturation temperature for intact SG pressures
-Average 10 Highest TCs-Stable or decreasing
Minimum RCS temperature(not for criticality)
70F Assures that vessel flange minimum of 60F when vessel head is tensioned
BGP 100-1 (Heatup procedure) oxygen limitation
The RCS Oxygen concentration shall be less than 0.1 ppm with RCS
temperature > 250F. See TRM 3.4.b for transient limitations.
BGP 100-6 (Refueling) temperature/RCP condition limitation
RCS Temperature shall not be raised above 160F until at least one RCP
is running for solid water, low pressure operation. (CM-1)
CV charging taps-which cold legs?
A and B. Use of the normal and alternate charging shall be alternated over plant life, such that neither should be used for more than 60% of design transients. The transfer should be done in cold shutdown to avoid transients, starting with CV8147 A loop in cycle 1.
Core bypass flow
5.8%
Head bypass 2.3
flow through Crs and instr thimbles 2
Inlet to outlet nozzle bypass 1
Former and baffle 0.5
Penetrations that extend into the RCS piping
- PZR spray lines
- NR Thot RTD thermowell
- WR RTD thermowell
- Chemistry sampling line
One reason for RCS subcooling:
(Delta T)
ensure delta-T is accurate indication of reactor power
NR RTD description
Fast response RTDs located directly in the RCS loops. Three for each hot leg and only one for each cold leg. Each hot leg RTDs are averaged to compensate for streaming.
RTD open circuit/short circuit indications
Open-High resistance, high temperature
Short- Low resistance, low temperature
Stop valve internal relief mechanism
Vents excess water to Reactor during isolated loop warmup
Vents excess water between disks
DNBR requirements from TRM
including when pressure limit doesn’t apply.
Flow 386000 gpm
PZR pressure >=2209 psig
Tave <=593.1F
PZR pressure limit doesn’t apply during thermal power ramp>5%/min or Thermal power step of >10%RTP
BGP-6 refuel precaution max boron concentration
2450ppm to prevent unnecessary reduction in the NI response
Purpose of the reactor vessel
The reactor vessel is the pressure boundary which contains the nuclear fuel. The reactor vessel internals align and support the fuel, direct support equipment and instrumentation into the vessel, and direct the flow of coolant through the core.
Reactor vessel head purpose
- Supports CRDMs, restrains upper internals, and forms upper pressure boundary.
- Head bolted and sealed to reactor vessel.
- Two O rings between head and vessel, leakage sensed if O rings leak.
upper support plate and columns
Support plate- supports upper core plate
support columns- support upper plate and transmit load to lower core plate
RCCA guide tubes
Guide and support the control rods into and out of the fuel assemblies
Upper core plate
Transmits upward forces of fuel assemblies to upper support plate.
Core barrel
Transmits core/fuel weight to vessel flange.
Neutron pads
Attenuate fast neutrons, minimize embrittlement of the vessel wall.
Lower core plate
Aligns and supports fuel assemblies and distributes coolant flow to fuel assemblies.
Lower support columns
Transmits weight of lower core plate and the core to the core support.
Core support
Transmits weight of the lower core plate and core to the core barrel.
Core baffle and former plates
Converts cylinder shape of core to box shape of fuel assemblies, minimizes bypass flow.
Loop isolation valves status at power
Deenergized open at power, no isolation capability at power
LCO 3.4.1
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling
(DNB) Limits
LCO 3.4.1 RCS DNB parameters for pressurizer pressure, RCS average
temperature (Tavg), and RCS total flow rate shall be within
the limits specified below:
a. Pressurizer pressure within the limit specified in the
COLR;
b. RCS average temperature (Tavg) within the limit specified
in the COLR; and
c. RCS total flow rate 386,000 gpm and within the limit
specified in the COLR.
—————————-NOTE—————————-
Pressurizer pressure limit does not apply during:
a. THERMAL POWER ramp > 5% RTP per minute; or
b. THERMAL POWER step > 10% RTP.
—————————————–
2 hour to restore
LCO 3.4.2 Minimum temp for criticality
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.2 RCS Minimum Temperature for Criticality
LCO 3.4.2 Each RCS loop average temperature (Tavg) shall be >= 550F.
APPLICABILITY: MODE 1,
MODE 2 with keff >= 1.0.
30 minutes to Mode 2, <1.0 keff
3.4.3 PTLR
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.3 RCS Pressure and Temperature (P/T) Limits
LCO 3.4.3 RCS pressure, RCS temperature, and RCS heatup and cooldown
rates shall be maintained within the limits specified in the
PTLR.
APPLICABILITY: At all times.
3.4.4 RCS loops operating
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.4 RCS Loops-MODES 1 and 2
LCO 3.4.4 Four RCS loops shall be OPERABLE and in operation.
APPLICABILITY: MODES 1 and 2.
3.4.5 mode 3
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.5 RCS Loops-MODE 3
LCO 3.4.5 Two RCS loops shall be OPERABLE, and either:
a. Two OPERABLE RCS loops shall be in operation when the
Rod Control System is capable of rod withdrawal; or
b. One OPERABLE RCS loop shall be in operation when the Rod
Control System is not capable of rod withdrawal.
—————————-NOTE—————————-
All reactor coolant pumps may be removed from operation for
1 hour per 8 hour period provided:
a. No operations are permitted that would cause reduction
of the RCS boron concentration; and
b. Core outlet temperature is maintained 10F below
saturation temperature.
————————————————————
APPLICABILITY: MODE 3.
What constitutes an operable SG per loop definition?
An OPERABLE RCS loop consists of one OPERABLE RCP and one
OPERABLE SG, which has the minimum water level specified in
SR 3.4.5.2. An RCP is OPERABLE if it is capable of being
powered and is able to provide forced flow if required.
SR 3.4.5.2 Verify steam generator secondary side
narrow range water level is >=18% for each
required RCS loop.
3.4.6 Loops Mode 4
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.6 RCS Loops-MODE 4
LCO 3.4.6 Two loops consisting of any combination of RCS loops and
Residual Heat Removal (RHR) loops shall be OPERABLE, and one
OPERABLE loop shall be in operation.
—————————-NOTES—————————
1. All Reactor Coolant Pumps (RCPs) and RHR pumps may be
removed from operation for 1 hour per 8 hour period
provided:
a. No operations are permitted that would cause
reduction of the RCS boron concentration; and
b. Core outlet temperature is maintained >= 10F below
saturation temperature.
2. No RCP shall be started with any RCS cold leg
temperature <= 350F unless the secondary side water
temperature of each Steam Generator (SG) is <= 50F above
each of the RCS cold leg temperatures.
————————————————————
APPLICABILITY: MODE 4.
3.4.7
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.7 RCS Loops-MODE 5, Loops Filled
LCO 3.4.7 One Residual Heat Removal (RHR) loop shall be OPERABLE and
in operation, and either:
a. One additional RHR loop shall be OPERABLE; or
b. The secondary side water level of at least two Steam
Generators (SGs) shall be >= 18%.
—————————-NOTES—————————
1. The RHR pump may be removed from operation for <= 1 hour
per 8 hour period provided:
a. No operations are permitted that would cause
reduction of the RCS boron concentration; and
b. Core outlet temperature is maintained >= 10F below
saturation temperature.
2. One required RHR loop may be inoperable for <= 2 hours
for surveillance testing provided that the other RHR
loop is OPERABLE and in operation.
3. No reactor coolant pump shall be started with any RCS
cold leg temperature <= 350F unless the secondary side
water temperature of each SG is >= 50F above each of the
RCS cold leg temperatures.
4. All RHR loops may be removed from operation during
planned heatup to MODE 4 when at least one RCS loop is
in operation.
————————————————————
APPLICABILITY: MODE 5 with RCS loops filled.
3.4.8
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.8 RCS Loops-MODE 5, Loops Not Filled
LCO 3.4.8 Two Residual Heat Removal (RHR) loops shall be OPERABLE and
one OPERABLE RHR loop shall be in operation.
—————————-NOTES—————————
1. All RHR pumps may be removed from operation for <= 1 hour
provided:
a. No operations are permitted that would cause a
reduction of the RCS boron concentration;
b. The core outlet temperature is maintained >=10F
below saturation temperature; and
c. No draining operations are permitted that would
further reduce the RCS water volume.
2. One RHR loop may be inoperable for <= 2 hours for
surveillance testing provided that the other RHR loop is
OPERABLE and in operation.
————————————————————
APPLICABILITY: MODE 5 with RCS loops not filled.
3.4.9 Pressurizer
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.9 Pressurizer
LCO 3.4.9 The pressurizer shall be OPERABLE with:
a. Pressurizer water level <= 92%; and
b. Two groups of pressurizer heaters OPERABLE with the
capacity of each group >=150 kW and capable of being
powered from redundant Engineered Safety Features (ESF)
power supplied buses.
APPLICABILITY: MODES 1, 2, and 3.
3.4.10 safety valves
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.10 Pressurizer Safety Valves
LCO 3.4.10 Three pressurizer safety valves shall be OPERABLE with lift
settings >= 2411 psig and <= 2509 psig.
—————————-NOTE—————————-
The lift settings are not required to be within the
LCO limits during MODE 3 for the purpose of setting the
pressurizer safety valves under ambient (hot) conditions.
This exception is allowed for 54 hours following entry into
MODE 3 provided a preliminary cold setting was made prior to
heatup.
————————————————————
APPLICABILITY: MODES 1, 2, and 3.
15 minutes to restore or mode 3 in 6 hours
3.4.11 PORVs
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.11 Pressurizer Power Operated Relief Valves (PORVs)
LCO 3.4.11 Each PORV and associated block valve shall be OPERABLE.
APPLICABILITY: MODES 1, 2, and 3.
ACTIONS
————————————- NOTE————————————
Separate Condition entry is allowed for each PORV and each block valve.
—————————————————————————–
If PORV capable of being cycled but inop? If not capable of being cycled?
Porv inop but can be cycled- block valve closed with power
PORV inop, can not be cycled- block valve closed, deenergized
3.4.12 LTOP
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.12 Low Temperature Overpressure Protection (LTOP) System
LCO 3.4.12 An LTOP System shall be OPERABLE with:
a. A maximum of one charging pump (centrifugal) capable of
injecting into the RCS;
b. No Safety Injection (SI) pumps capable of injecting into
the RCS;
c. Each SI accumulator isolated, whose pressure is greater
than or equal to the maximum RCS pressure for the
existing RCS cold leg temperature allowed by the P/T
limit curves provided in the PTLR; and
d. One of the following pressure relief capabilities:
1. Two Power Operated Relief Valves (PORVs) with lift
settings within the limits specified in the PTLR,
2. Two Residual Heat Removal (RHR) suction relief
valves with setpoints <= 450 psig,
3. One PORV with a lift setting within the limits
specified in the PTLR and one RHR suction relief
valve with a setpoint <= 450 psig, or
4. The RCS depressurized and an RCS vent of
<= 2.0 square inches.
—————————-NOTES—————————
1. Operation in MODE 4 with all SI pumps and charging
pumps capable of injecting into the RCS is allowed when
all RCS cold legs exceed 330F.
2. For the purpose of protecting the decay heat removal
function, one or more SI pumps may be capable of
injecting into the RCS in MODE 5 and MODE 6 when the
reactor vessel head is on provided pressurizer level is
≤ 5 percent.
————————————————————
APPLICABILITY: MODES 4 and 5,
MODE 6 when the reactor vessel head is on.
3.4.13 Leakage
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.13 RCS Operational LEAKAGE
LCO 3.4.13 RCS operational LEAKAGE shall be limited to:
a. No pressure boundary LEAKAGE;
b. 1 gpm unidentified LEAKAGE;
c. 10 gpm identified LEAKAGE; and
d. 150 gallons per day primary to secondary LEAKAGE through
any one steam generator (SG).
APPLICABILITY: MODES 1, 2, 3, and 4.
3.4.14 PIV leakage limits
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.14 RCS Pressure Isolation Valve (PIV) Leakage
LCO 3.4.14 Leakage from each RCS PIV shall be within limits.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTIONS
————————————-NOTES ———————————–
1. Separate Condition entry is allowed for each flow path.
2. Enter applicable Conditions and Required Actions for systems made
inoperable by an inoperable PIV.
——————————————————————————
Hot 57 chevy low rider
Cold 6 pack of lowenbreau
Valve 455A Auct. WR Low Thot and PT-407
5 Low Hot 7
Valve 456 Auct WR Low Tcold and PT-406
6 Low Cold 6 LOWenbreau
3.4.15 RCS leakage detection
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.15 RCS Leakage Detection Instrumentation
LCO 3.4.15 The following RCS leakage detection instrumentation shall be
OPERABLE:
a. One containment sump monitor; and
b. One containment atmosphere radioactivity monitor
(gaseous or particulate).
APPLICABILITY: MODES 1, 2, 3, and 4.
3.4.16 RCS specific activity
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.16 RCS Specific Activity
LCO 3.4.16 RCS DOSE EQUIVALENT I-131 and DOSE EQUIVALENT XE-133
specific activity shall be within limits.
APPLICABILITY: MODES 1, 2, 3, and 4.
SR 3.4.16.1 Verify reactor coolant DOSE EQUIVALENT
XE-133 specific activity <= 603 Ci/gm.
SR 3.4.16.2 Verify reactor coolant DOSE EQUIVALENT
I-131 specific activity <= 1.0 Ci/gm.
3.4.17 loop isolation valves
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.17 RCS Loop Isolation Valves
LCO 3.4.17 Each RCS hot and cold leg loop isolation valve shall be open
with power removed from each isolation valve operator.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTIONS
————————————-NOTE————————————-
Separate Condition entry is allowed for each RCS loop isolation valve.
——————————————————————————
3.4.18 loop isolations shutdown
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.18 RCS Loops-Isolated
LCO 3.4.18 Each RCS isolated loop shall remain isolated with:
a. The hot and cold leg loop stop isolation valves closed
if boron concentration of the isolated loop is less than
the required SDM boron concentration of the unisolated
portion of the RCS; and
b. The cold leg loop stop isolation valve closed if the
cold leg temperature of the isolated loop is > 20°F
below the highest cold leg temperature of the unisolated
portion of the RCS.
APPLICABILITY: MODES 5 and 6.
3.4.19 SG tube integrity
3.4 REACTOR COOLANT SYSTEM (RCS)
3.4.19 Steam Generator (SG) Tube Integrity
LCO 3.4.19 SG tube integrity shall be maintained.
AND
All SG tubes satisfying the tube plugging criteria shall be
plugged in accordance with the Steam Generator Program.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTIONS
——————————–NOTE—————————————–
Separate Condition entry is allowed for each SG tube.
—————————————————————————–
3 control functions that use the validated second highest Tavg
Rod Control, Steam dump control and pressurizer level control
RCP start logic
- Hot and cold leg isol valves open or hot leg open/bypass open
- Control switch to start
- Lift pressure >600 psig
Auto open and auto close of 8114 and 8116 CV mini recircs:
Auto open: 2/4 WR pressure >=1643psig
SI
Auto Close with:
-SI
-2/4 WR Press < 1448 psig
(4030 will show ¾ required to
be < 1643 psig to close)
WR PT403/405/408/409
RH suction valve open interlocks?
Can open when RCS pressure <=360 psig admin
<=337# interlock
Connect to A and C hot legs
PT403 and 405
Physics test exceptions:
RCS Tave>=530F
SDM wi/in 1300 pcm
Therm power <=5%
LCOs suspended:
3.1.3 MTC
3.1.4 Rod group alignment
3.1.5 SDBIL
3.1.6 CBIL
3.4.2 RCS minimum temp for criticality
OTdeltaT delta I bands
-18% to +10%
Penalties above 10% and below -18%
OPdelta T and OT delta T baseline setpoints
107.2%-penalties and 132.5%+-penalities
Tave and delta T setpoints for control and alarm
Tave>Tref 3F will bring alarm
2nd highest validated Tave and delta T used for :
-Rod control, rod insertion limit, steam dump, pzr level control
delta T
-computer, rod insertion limit
TS 3.4.6, if a required loop inoperable, what actions required?
What if RHR is not operable?
Restore immediately and be in Mode 5 within 24 hours. If RHR not operable stay in mode 4.
