IPT 1 Flashcards
You are directed to raise power on the Unit from 20-50% power. Which procedure do you use to determine the maximum power escalation rate?
1[2]-GOP-101, Reactor Operating Guidelines During Steady State and Scheduled Load Changes
Unit 2 has been operating at 100% power for months. The Unit unexpectedly trips due to equipment failure. The plant is shutdown for 21 days for repairs. What is the maximum allowed power escalation rate?
IF performing a mid cycle shutdown or power reduction AND a return to full power occurs within 27 days, THEN RAISE power at a maximum power escalation rate of 30% / hour.
Unit 1 operated at 45% power for 5 days and then shutdown due to equipment problems. Unit 1 has been restarted and raising power from 20-40%. What is the maximum power escalation rate?
1-GOP-101
4.8 MW/Min
This is a ‘Category 2’ condition.
What procedure(s) provide(s) the ASI Steady State and Transient Bands?
1[2]- GOP-101, Reactor Operating Guidelines During Steady State and Scheduled Load Changes
0-NOP-100.02, Axial Shape Index Control
What is the ASI Steady State control band?
Steady State Band:
* ESI plus or minus 0.5 during steady state base load operation
What is the ASI Transient control band?
Transient Band:
* ESI plus or minus 0.2 during load transients.
* ASI control to plus or minus 0.1is recommended whenever practical.
State the Technical Specification Limit for RCS T-cold
RCS T-cold shall be maintained less than or equal to 551°F per
Technical Specification 3.2.5 and COLR Table 3.2-1
At greater than or equal to 50% power, boration/dilution is the primary means to compensate for changes in power level and transient xenon. Why?
Using boration/dilution to compensate for power changes subjects the majority of the fuel rods to uniform and smooth power transients.
What method is used for monitoring RCS T-cold when maintaining steady state power level?
DCS is the preferred method for monitoring T-cold
Average of four channels of RPS T-cold may be substituted when DCS T-cold is unreliable.
As the RCO, what is the 100% power RCS T-cold band to be maintained?
Maintain 100% power T-cold between 550.4 and 550.6F
Why is the pressurizer placed on recirculation if plant power is being changed?
To maintain the pressurizer and RCS boron concentration within 25ppm while changing boron concentration.
You’ve been directed to remove the pressurizer from recirculation. How many Backup Heater Banks are typically in service during steady state conditions?
Enough Backup Heater banks to keep the Proportional Heater banks at approximately 50% output
How are ESI and ASI related?
Equilibrium Shape Index (ESI) is the value of the ASI in equilibrium condition at the power level to which the reactor will be bought for continued operations.
This value represents the average ASI target for the core.
When is the ‘sliding scale’ ESI value used?
During reactor startups and shutdowns and power maneuvers greater than 10%
Above what power level is ASI control required at all times?
APPLY Axial shape control under the following conditions:
At all times when core power is at or above 40% of rated power
Should be considered and established as soon as possible after exceeding 25% power
CEA withdrawal during power operation > 50% power is limited to small steps. Why?
CEA withdrawal during power operation greater than 50% power should be in small steps. Withdrawal in excess of 10 inches in any 15 minute period should be avoided. This technique should reduce the likelihood of fuel failures due to large local power density changes in the vicinity of the CEA finger tips.
As the RCO you are operating the reactor at 100% power, steady state conditions. If RCS-T-cold drifts high, at what temperature do you have to take action?
550.8F to avoid exceeding 551F
Why don’t we reduce plant power and with draw CEAs at the same time for ASI control?
Simultaneous power reduction / CEA withdrawal or power escalation / CEA insertion should NOT be carried out since both actions tend to accelerate the axial power shape shift in the same direction and thus induce xenon oscillations. These actions could also result in a rapid shift of the ASI outside the transient band.
What is the maximum permissible pressure differential between condensers?
The maximum permissible pressure differential between Condensers is 2.0 inHgA.
What is the Manual Turbine Trip Criteria for Condenser Differential Pressure?
A manual Turbine trip is required at 2.5 inHgA pressure differential between Condensers.
S/G wide range level changes 1%. What is the corresponding change in S/G narrow range level?
5%
State the turbine trip criteria for the following conditions:
a. Turbine Bearing #1 - #6 maximum BRG Metal Temp
b. Turbine Bearing #7 and #8 maximum BRG Metal Temp
c. Turbine Bearing #1 – 9 Oil drain Temp
Turbine BEARING # 1 thru BEARING # 6 maximum BRG
METAL TEMP is less than: (Turbine Trip Criteria) 250°F
Turbine BEARING # 7 and BEARING # 8 maximum BRG
METAL TEMP is less than: (Turbine Trip Criteria) 225°F
Turbine BEARING # 1 thru BEARING # 9 OIL DRAIN TEMP is
less than: (Turbine Trip Criteria) 180°F
Why are there limits on Turbine Exhaust Hood Temperatures?
To avoid unnecessary stress due to expansion of the exhaust chamber and misalignment of the low pressure turbine inner cylinder and rotor, exhaust hood temperatures should be adhered to as follows:
DEH display 5559, TURBINE EXHAUST HOOD SPRAY AND CONDENSER VACUUM, may be used to monitor both LP Turbines exhaust hood conditions:
* High EXHAUST HOOD TEMP Turbine trip is 250°F.
* High EXHAUST HOOD TEMP alarm is 175°F.
* Exhaust hood sprays automatic actuation 160°F.
* Maximum EXHAUST HOOD TEMP DIFF between LP Turbines should NOT exceed 50°F.
Normally the plant operates with all four MSRs in service. Is the plant allowed to operate for extended periods with less than four MSRs?
Extended Power Operations with less than all four Moisture Separator Reheaters in service shall have a documented engineering analysis on a case-by-case basis.
How long can the U2 main turbine operate at 56.9 Hz during a single event? Why?
Main Generator Under Frequency Relay instantaneously trips at 57 HZ.
Unit 2 Main Generator hydrogen pressure is being reduced during a power reduction for refueling. Hydrogen pressure is 45 psig. What is the maximum MW output per the capability curve?
960 MW
A power reduction on Unit 1 is underway. The 1A Heater Drain Pump is operating below its minimum flow requirement. What is the value of the limit and what do you do?
Heater Drain Pump minimum flow requirement is 1500 gpm per pump. Pump shall be stopped if flow drops below 1500 gpm to prevent damage to the pump.
The Unit 2 turbine is off-line, but the reactor is being maintained critical. What indication is used to determine power level?
Delta-T power is NOT accurate with the turbine off-line. If reactor is to be maintained critical after the turbine trip (prior to placing the turbine on-line), WR Power and Nuclear Power should be closely monitored while controlling power.
A power reduction for plant shutdown is in progress. What is the concern when placing the control switch for a MFP in RECIRC?
Main Feed Pump suction pressure should be maintained greater than 355 PSIG to preclude tripping of one or both Main Feed Pumps on low suction pressure.
What power level are the Heater Drain Pumps secured during a normal plant shutdown?
WHEN any of the following conditions are met:
* Power is approximately 70%
* 1A Heater Drain pump flow is less than 1500 gpm indicated on FIS-11-4A, HTR DRN PUMP 1A DISCH FLOW.
* 1B Heater Drain pump flow is less than 1500 gpm indicated on FIS-11-4B, HTR DRN PUMP 1B DISCH FLOW.
Unit 2 has LP Inlet (OPC) Pressure of 60 psig. Condenser Back Pressure is 8.0 inHGA. How long will the plant operate under these conditions?
RESTRICTED OPERATING REGION: When LP Inlet Pressure is between 7.9 psig and 116 psig, two “Trip” setpoints exist. The Prohibited Operating Region is the Restricted Operating Region’s upper Trip boundary which exists at 8.859 inHgA Condenser Back Pressure. Another Trip setpoint exists below 8.859 inHgA and varies based on power level. The area between these two Trip setpoints is the Restricted Operating Region. Operating in the RESTRICTED OPERATING REGION for 300 seconds (5 Minutes) will automatically generate a Turbine Trip. DEH displays 5559 and 5605 contain two timers that track the duration inside the Restricted Operating Region during an event. Entry into the Restricted Operation Region should prompt a load change or other actions to immediately return to the Acceptable Operating Region.
However, the time spent in the Restrictive Operating Region shall be tracked and documented. The plant has an accumulative life time limit of 300 minutes in this region which is based on the working life of the LP
Turbine last blade row. System Engineering uses the CR process as notification of all time spent operating the Turbine in the Restricted Operating Region. DEH display 5559 contains a TOTAL TIME IN TRIP DELAY REGION group that tracks the accumulative life total.
What power level is the first Main Feed Pump secured during a normal plant shutdown?
Approximately 45%
When a Main Feed Pump is stopped, does MFP discharge valve auto-close? Does MFP Recirc valve auto- close?
Yes, Yes
When is the PSS (Power System Stabilizer) removed from service during a normal plant shutdown?
Approximately 45%
Who needs to be notified and within what time period when PSS taken out of service?
The System Load Dispatcher shall be notified as soon as practical, but within 30 minutes of a change in status of the PSS.
Unit 2 is being shutdown and the PSS has been taken out of service. Unit 1 is online with PSS in service. What is the Mvar limit for Unit 2?
Condition Unit 2 Reactive Load Limit (Mvar)
1) Unit 2 online with PSS in service.
Capability Curve limits (Attachment 8)
2) Unit 1 online with PSS in service, Unit 2 online with PSS off.
Capability Curve limits (Attachment 8)
3) Unit 1 offline, Unit 2 online with PSS off.
CONTACT System Load Dispatcher to obtain reactive load limits. See NOTE 1
4) Unit 1 online with PSS off, Unit 2 online with PSS off.
CONTACT System Load Dispatcher to obtain reactive load limits. See NOTE 1
NOTE 1: Reactive load limit depends on current system condition.
Why do the reactive load limitations for the PSS in/out of service exist?
The reactive load limitations of Attachment 7, Unit 2 Reactive Load Limitations maintain stability for a three phase fault on the Midway 500/230 kV autotransformer.
Will the MSRs automatically close their TCVs?
The DEH Ovation system is programmed to automatically select Ramp Down mode for the MSRs if turbine load is below 257.5 MW for greater than 15 minutes, provided LP inlet temperature is above 400F and MSR control mode is either Auto Time or Auto Temp. If the Ramp Down mode automatically begins closing the MSR TCVS, then it is both preferable and acceptable to remove the MSRs from service per Attachment 4, Removing MSRs From Service.
IAW 1[2]-GOP-123, how is the reactor made subcritical?
Trip from 25% power. If there is a tube leak, the reactor is shutdown IAW 1[2]-GOP-203.
When the Unit 2 is being shutdown, there is a choice for how the station electrical loads are transferred from the Auxiliary Transformers to the Startup Transformers depending on whether the plant is shutting down for refueling or not. What’s the difference?
For a normal shutdown (non-refueling), the transfer from AUT to SUT is done manually IAW Att. 1.
If shutting down for refueling then use Att 1 to manually transfer to SUTs. Then use Att 2 to transfer SUTs back to AUTs. When the turbine is tripped, check to verify that AUTs auto transfer to SUTs.
When and why do the Turbine Drain Valves open during downpower?
Turbine Drain Valves shall be open below 20% load to prevent water damage to the Turbine.
Prior to reducing power to less than 15%, PERFORM the following:
A. IF a Linear Range Safety Channel nuclear power detector is
out of service, THEN PLACE High Startup Rate trip bistable
for affected channel in bypass or trip condition.
What’s the reason for this step?
Linear Range Safety Channel is the input for the LIN 1 Bistable. When less than 15% power, the Hi SUR trip needs to be enabled per TS.
IAW 2-GOP-123, when power is < 15%, then “ENSURE no more than one ADV per Steam Generator is in automatic control”. Why?
Basis for this step is not referenced in ITS.
What is the concern with using the Main Feedwater system without condenser vacuum?
Use of Main Feedwater with NO Main Condenser Vacuum will cause large amounts of oxygen to be introduced into the Steam Generators.
State the definitions of Operating Modes per Technical Specifications
1 Power Operation keff ≥ 0.99 Pwr > 5%
2 Startup keff ≥ 0.99 Pwr ≤ 5%
3 Hot Standby keff < 0.99 Temp ≥ 325
4 Hot Shutdown(b) keff < 0.99 325 > Tavg > 200
5 Cold Shutdown(b) keff < 0.99 Temp ≤ 200
6 Refueling(c) ≥ 1 head bolt detensioned
Per the Technical Specifications, when do you enter Mode 6?
When the first vessel closure head is less than fully tensioned
What is the reason for NOT running four RCPs simultaneously below 500⁰F?
Four RCPs shall NOT be operated simultaneously below 500°F RCS temperature due to fuel uplift considerations.
How often is RCS boron concentration determined during a plant cooldown?
RCS boron concentration shall be determined every 50°F during cooldown.
RCS pressure shall be maintained greater than SIT pressure until
SIT Outlet Isolation Valves are Closed in MODE 4. What is the highest SIT pressure on Unit 1 and Unit 2 per TS?
Unit 1
LIMITING CONDITION FOR OPERATION
3.5.1 Each reactor coolant system safety injection tank shall be OPERABLE with:
a. The isolation valve open,
b. Between 1090 and 1170 cubic feet of borated water,
c. A minimum boron concentration of between 1900 ppm and 2200 ppm, and
d. A nitrogen cover-pressure of between 230 and 280 psig.
APPLICABILITY: MODES 1 and 2, Mode 3 with pressurizer pressure > 1750 psia.
Unit 2
LIMITING CONDITION FOR OPERATION
3.5.1 Each Reactor Coolant System safety injection tank shall be OPERABLE with:
a. The isolation valve open,
b. A contained borated water volume of between 1420 and 1556 cubic feet,
c. A boron concentration of between 1900 and 2200 ppm of boron, and
d. A nitrogen cover-pressure of between 500 and 650 psig.
APPLICABILITY: MODES 1 and 2, Mode 3 with pressurizer pressure > 1750 psia.
Why is hydrogen peroxide added to RCS if cooling down for refueling outage?
Initiate a Crud Burst
Why is the time spent with RCS pressure between 1100 psia and 1400 psia minimized during plant shutdowns?
During plant shutdowns, the time spent with RCS pressure between 1100 psia and 1400 psia should be minimized to avoid seal damage due to shuttling (up-thrusting). Three to four hours is normal.
Why are the Containment Spray and NaOH (IRS) isolated prior to initiating SDC operations?
To prevent overpressurization
Unit 1: State Administrative and Technical Specification RCS Cooldown limits
The following administrative RCS cooldown rate limits should be followed in order to prevent exceeding the maximum allowable cooldown rates of Technical Specification {CTS 3.4.9.1, Reactor Coolant System Pressure / Temperature Limits} {ITS 3.4.3, RCS
Pressure and Temperature (P/T) Limits}:
Administrative Limit
85°F per hour down to 200°F *
40°F per hour between 200°F and 150°F
20°F per hour below 150°F
Technical Specification Limit
100°F per hour down to 180°F
50°F per hour between 180°F and 160°F
40°F per hour between 160°F and 145°F
30°F per hour between 145°F and 125°F
20°F per hour below 125°F
* When a single train of shutdown cooling is used for cooldown, cooldown rate shall be maintained less than 75°F per hour per LTR-SEE-II-09-22.
Unit 2: State Administrative and Technical Specification RCS Cooldown limits
The following administrative RCS cooldown rate limits should be followed in order to prevent exceeding maximum allowable cooldown rates of ITS 3.4.3, RCS Pressure and Temperature (P/T) Limits:
Administrative Limit
85°F / hr down to 212°F*
40°F / hr below 212°F
Technical Specification Limit
100°F / hr down to 212°F
50°F / hr below 212°F, down to 60F
* When a single train of shutdown cooling is used for cooldown, cooldown rate shall be maintained less than 75F / hr per LTR-SEE-II-09-63.
Unit 1: State Administrative and Technical Specification Pressurizer Cooldown limits
The pressurizer temperature shall be limited to:
a. A maximum heatup of 100 °F in any 1-hour period,
b. A maximum cooldown of 200 °F in any 1-hour period, and
c. A maximum spray water temperature differential of 350 °F.
An administrative maximum rate of 75F per hour is recommended for Pressurizer cooldown.
Unit 2: State Administrative and Technical Specification Pressurizer Cooldown limits.
The pressurizer temperature shall be limited to:
a. A maximum heatup of 100 °F in any one hour period, and
b. A maximum cooldown of 200 °F in any one hour period.
AND
Each PORV shall be FUNCTIONAL.
An administrative maximum rate of 75F per hour is recommended for Pressurizer cooldown.
What is the minimum Reactor Coolant flowrate allowed by Technical Specifications if RCS boron concentration is being reduced?
Flow rate of Reactor Coolant shall be greater than 3000 GPM whenever a reduction in RCS boron concentration is in progress.
Unit 1: State the upper limits on RCS temperature and Pressure when SDC is in operation.
WHEN SDC system is in OPERATION, THEN do NOT exceed 267 psia Pressurizer pressure or 325°F RCS temperature.
Unit 2: State the upper limits on RCS temperature and Pressure when SDC is in operation.
Do NOT exceed 275 psia Pressurizer pressure or 325°F RCS temperature with SDC system in operation.
In Mode 5, what are the requirements for RCS heat removal per TS?
LCO 3.4.7 One shutdown cooling (SDC) loop shall be OPERABLE and in operation and either:
a. One additional SDC loop shall be OPERABLE or
b. The secondary side water level of each steam generator (SG) shall be ≥ 10% narrow range.
———————-NOTES———————–
1. The SDC pump of the loop in operation may be removed from operation for ≤ 1 hour per 8 hour period provided:
a. No operations are permitted that would cause introduction of coolant into the RCS with boron concentration less than required to meet the SDM of LCO 3.1.1, “SHUTDOWN MARGIN (SDM),” and
b. Core outlet temperature is maintained at ≥ 10°F below saturation temperature.
2. One SDC loop may be inoperable for up to 2 hours for surveillance testing provided that the other SDC loop is OPERABLE and in operation.
3. No reactor coolant pump (RCP) shall be started with two idle RCS loops unless secondary side water temperature in each SG is < 30°F above each of the RCS cold leg temperatures.
4. All SDC loops may not be in operation during planned heatup to MODE 4 when at least one RCS loop is in operation.
————————————————————————————————–
APPLICABILITY: MODE 5 with RCS loops filled.
Unit 2
Same as Unit 1 with the exception of note #3:
3. No reactor coolant pump (RCP) shall be started with two idle RCS loops unless secondary side water temperature in each SG is < 40°F above each of the RCS cold leg temperatures.
Per 2-GOP-305, in Mode 5, what is the criteria necessary to take credit for the steam generators?
In MODE 5, Cold Shutdown, at least one of the following Reactor Coolant Loops / heat removal capabilities are required:
A. Two loops of SDC OPERABLE AND at least one loop OPERATING.
B. One loop of SDC OPERATING, AND both Reactor coolant loops filled per the following criteria:
(1) The RCS has NOT been drained below 63 inches as indicated on LI-1117-1, RX REFUELING WATER LEVEL - WR, (PACB-2) since the last RCS fill and vent was performed per 2-NOP-01.05, Filling and Venting the RCS.
(2) Both Steam Generator Narrow Range levels are greater than 10%.
NOTE
Time required to pressurize RCS to greater than or equal to 70 psia before core boiling starts depends on the following variables:
If SDC is lost, time before core boiling starts
Time required to isolate all Pressurizer and RCS vents
Available Pressurizer fill rate
Pressurizer level
(3) RCS is capable of being pressurized to greater than or equal to 70 psia (55 psig) prior to initiation of core boiling.
What value is the RCS dissolved H2 reduced to for a refueling outage?
< 5cc/kg
How do we reduce the H2 in the RCS?
Purge VCT IAW 1[2]-NOP-02.05, Volume Control Tank Hydrogen and Nitrogen Concentration Control
If we use main or auxiliary spray during a plant cooldown, when do we have to initiate a report ADM-17.43, Component Cycles and Transients? Is it the same on both units?
Unit 1
IF main or auxiliary spray actuates with less than 4 RCPs in OPERATION, THEN INITIATE a report per ADM-17.43, Component Cycles and Transients.
Unit 2
IF main or auxiliary spray actuates with less than 4 RCPs in operation, THEN INITIATE a report per ADM-17.43, Component Cycles and Transients.
IF main or auxiliary spray actuates with greater than 200°ΔT between Charging fluid and Pressurizer Spray Nozzle, THEN INITIATE a report per ADM-17.43, Component Cycles and Transients.
When a Unit 2 plant cooldown is conducted, Reg. Guide 1.63 components need to be re-energized. Why do we have to do this and what type of components are they?
NOTE
Power is removed from this equipment during MODE 1 (Power Operation) and MODE 2 (Startup) to ensure compliance with Reg. Guide 1.63, Electric Penetration Assemblies in Containment Structures for Nuclear Power Plants.
1. RESTORE power to the following equipment:
C
Shutdown Cooling Isolation Valve V-3480
Shutdown Cooling Isolation Va V-3481
Shutdown Cooling Isol. Valve V-3652
Shutdown Cooling Isolation Va V-3651
Shutdown Cooling Isol Valve V-3545
Reac Bldg Elevator Rm Exh. Fan 2-HVE-22
Refueling Equipment Main Breaker Pnl
Refueling Machine Pool End JB
When conducting an RCS cooldown IAW 1[2]-GOP-305, how often do you plot the RCS and Pressurizer Temperatures? How do you know what instruments to use?
1[2]-GOP-305 Attachment 12[13]
Temperatures are plotted every 30 minutes
TI-1101 for the Pzr
TI-1115 or 1125 for Highest Tc Loop with a running RCP
When plotting cooldown temperatures, do you plot the highest or lowest Tc if RCPs are running?
Highest Loop Tc with running RCP
What is the preferred method for depressurizing the RCS with RCPs in operations? Why?
Auxiliary Spray is NOT recommended due to thermal stresses resulting fromthe differential temperature between Charging fluid and Pressurizer Spray Nozzle and should be limited to instances where Main Spray is inadequate or unavailable.
Why is an RCS depressurization to < 1800 psia initiated as soon as possible if there are less than 4 RCPs in operation?
With less than 4 RCPs in OPERATION, RCS depressurization to less than1800 psia should be started as soon as possible to minimizes differential pressure across seal of idle RCP(s) while NO means of seal cooling exists.
During a Unit 1 cooldown and depressurization, the maximum pressurizer temperature is limited to < 350°F above RCS temperature. Why?
To prevent thermal stress on surge line, Pressurizer temperature shall NOT be greater than 350°F above RCS temperature.
What is the preferred RCP configuration for plant cooldown? Why?
Preferred RCP operating configuration is both RCPs in Loop B operating. This configuration provides maximum Pressurizer Main Spray flow and allows RCP operation at lower RCS pressures than any other combination. This will also allow parallel RCP and SDC operation to cool Steam Generators.
IF plant conditions necessitate other RCP operating combinations, THEN parallel SDC / RCP operation will NOT be allowed until a significantly lower RCS temperature is achieved.
1-NOP-01.02, Reactor Coolant Pump Operation, Minimum RCS Pressure for RCP Operation, provides minimum RCS pressures versus temperatures for RCP operation.
When is the Containment Spray System isolated?
< 1750 psia
As a plant cooldown is implemented, SG Blowdown will automatically isolate. When does it isolate and why is it restored?
Steam Generator Blowdown Containment Isolation Valve will automatically close at 600 psig secondary pressure which corresponds to RCS temperature of 490ºF.
Priority should be given to restoring Steam Generator Blowdown expeditiously following automatic isolation. This provides additional cooling capacity and aids in meeting the initial conditions for placing Shutdown Cooling in service.
A Unit 2 cooldown is in progress. RCS pressure is < 750 psia. The fuses for Pressurizer Pressure PI-1103/1104/1105/1106 are inserted. What control functions do these instruments provide?
SIT outlet valves (permissive to close < 276 psia, auto open > 500 psia
SDC hot leg suction isolation valves (permissive to open < 276 psia, auto close > 500 psia)
LTOP (PORVs) (open > 490 psia)
Unit 2 cooldown in progress. RCS T = 350°F. 2B1 and 2B2 RCPs are in service. What is the Minimum Pressure for RCP operation?
300 psia
When are the SITs (Safety Injection Tanks) isolated on U1 and U2?
Unit 1
RCS pressure at 325 psia
Unit 2
RCS T < 325°F and RCS Pressure < 276 psia
What are the upper and lower pressure limits for placing SDC in service at 300°F on Unit 2?
Upper limit: 275 psia
Lower limit: ~245 psia based on RCP NPSH
NOTE
When opening SDC suction isolation valves, RCS pressure should be maintained at low end of band between 275 psia and minimum RCP pressure requirements for RCP operation to avoid challenging SDC suction relief valves.
Why is the amount of time SDC System is operated with RCS Temperatures > 300°F limited?
The amount of time SDC System is operated with RCS temperature above 300°F should be minimized. Prolonged operation at elevated temperatures may result in undesirable rates of LPSI pump seal degradation.
Unit 1 is cooling down, when is the first HPSI pump removed from service? Why?
When is the second HPSI pump removed from service?
First pump taken out of service T < 270°F
Second pump out of service 237 – 250°F
Prior to decreasing RCS temperature below 270°F, REMOVE one HPSI Pump from service for compliance with Technical Specification 3.4.12, Low Temperature Overpressure Protection (LTOP) System
WHEN RCS temperature is between 250°F and 237°F, THEN DISABLE remaining HPSI Pump as follows for compliance with the following Technical Specifications:
* 3.4.12, Low Temperature Overpressure Protection (LTOP) System
* TRM 13.1.3, Boration System – Shutdown
Unit 2 is cooling down, when is the first HPSI pump removed from service? Why?
When is the second HPSI pump removed from service?
First pump: Prior to reducing RCS T < 241°F,
Second pump <200°F
A plant cooldown is in progress with SDC in operation in conjunction with RCPs. When do we secure the last RCP? Why?
RCS T < 175°F to avoid unintended mode change
CAUTION
● Loss of heat input from operation of RCP’s may result in a rise in RCS cooldown rate. Cooldown rate should be monitored and SDC flow through SDC Heat Exchangers adjusted as necessary following securing of last operating RCP’s.
● When the remaining RCP’s are initially secured, RCS flow decreases (even with SDC in service). Due to the longer loop transport time, hot leg temperature will initially rise (in excess of 15F in some cases).
Therefore, RCS temperature should be lowered to provide sufficient margin to prevent an unplanned Mode change (ensuring RCS temperature is less than 175F, in order to prevent going from Mode 5 to Mode 4 when RCS temperature exceeds 200F).
During a plant cooldown, when are charging pumps disabled on Unit 1? Unit 2?
Unit 1 and Unit 2 RCS T < 150°F
How can you tell if the pressurizer is solid?
Any of the following indications may be used to determine that pressurizer has become solid:
PIC-2201, LETDOWN PRESSURE, output starts increasing to limit RCS pressure rise.
Letdown flow starts rising.
Letdown and RCS pressure start rising.
With PIC-2201 in AUTO, pressure may be expected to rise to approximately 150 PSIG before controller and valve response times stabilize system pressure.
The unit is on solid pressure control. How is the pressurizer cooled to < 150°F?
When filling Pressurizer, pressurizer temperature may lower to less than 150F. Once pressurizer is solid, pressurizer temperature may begin to rise due to heating from pressurizer metal. The following step uses auxiliary flow to enhance pressurizer cooling. A rising temperature indication on TI-1105, SURGE LINE TEMPERATURE, indicates that recirculation flow is occurring.
Unit is in Mode 3, just prior to initiating a cooldown. How many charging pumps should be in service?
To ensure maximum cooldown and makeup capability, all three Charging Pumps should be in service prior to starting a plant cooldown, and remain in service until MODE 4.
When is the “Boration Flow Surveillance” performed?
Shall be performed every refueling outage and should be performed during boration to refueling boron concentration.
How many charging pumps are running when Boration Flow Surveillance is performed on Unit 1 and Unit 2?
Unit 1: 3 Pumps
Unit 2: 2 pumps
How do we normally borate to refueling boron concentration?
We use 1(2)-NOP-02.24, Boron Concentration Control. We use the section for “Rapid Boration”. We borate via the Emergency Borate Valve V2514 from RWT or BA tanks.
List the three major design changes between Unit 1 and Unit 2 SDC.
Unit 2 does not have air operated valves
Unit 2 has full flow shutdown cooling relief valves (SDCRV)
Unit 2 has independent train design
The unit is on Shutdown Cooling. What is the minimum SDC flowrate allowed when reducing RCS boron concentration?
3000 gpm
During a U-2 plant cooldown, when we align the SDC system for heat removal, how will we prevent losing coolant when the SDC suction line isolation valves from the RCS are opened?
- SDC piping has been vented to ensure that it is filled. (Ref:
2-NOP-03.05, Shutdown Cooling) - We will monitor Pressurizer level vs. HUT and containment sump level to detect potential relief valve lifting.
- SDC will be pressurized using containment spray or suction valves will be manually OPENED.
When drawing a steam bubble in the pressurizer, how do we control pressure to prevent lifting the SDC pump suction line relief valve?
Letdown PCVs are set to control pressure at 250 psia
How can you identify which procedure to use based on plant conditions for RCS and refueling cavity filling and draining evolutions?
Several of the fill and drain NOPs contain a matrix. SDC procedure also contains a matrix.
When manipulating SDC/LPSI system, there is always the issue of what position the LPSI pump switch should be left in. What is the guidance provided in 1[2]-NOP-03.05?
Pump control switches shall be aligned as follows:
A. If automatic start capability is required for current plant mode, pump control switch shall remain in AUTO at all times when pump is considered operable.
B. If automatic start capability is NOT required for current plant mode, pump control switch may be in any position. Power must be available to motor through a racked-in or closed breaker.
During SDC operation, how many SDC loops would be expected to be in operation if RCS water level is > 33 feet? What if level is < 33 feet?
When RCS water level is greater than 33 feet (63 inches on LI-1117-1, REFUELING LEVEL) one or two loops of SDC may be operating.
When RCS is in reduced inventory (water level less than or equal to 33 foot elevation, 63 inches on LI-1117-1) 1A LPSI pump should be in service and 1B LPSI pump should be in standby. Operation in reduced inventory shall be per 1-NOP-01.04, Reduced Inventory and Mid-Loop Operation.
On Unit 2, which SDC loop is normally in service and which is in standby?
Due to the suction piping arrangement, SDC Loop 2A is subject to experience adverse suction conditions before SDC Loop 2B.
Therefore, to improve the ability to recover the SDC system from a single failure, SDC Loop 2A will be operated in reduced inventory and SDC Loop 2B will be in standby.
On Unit 2, how can you determine what the position of V3545, Tie Isolation Valve, position should be based on plant condition?
2-NOP-03.05, Attachment 3
Unit 2 is in Mode 4 with Shutdown cooling in service. What is the maximum SDC flow per LPSI pump?
<4600 gpm per pump
Unit 2 is in a refueling outage. RCS level is 31 feet. RCS Temperature is 125 F? What is the maximum flowrate allowed for 2A LPSI pump?
2900 gpm
The plant is mid-Outage. A valid containment evaluation alarm has occurred and containment has been evacuated. Who must provide approval for resume activities inside containment?
SM and Radiation Protection Manager or on-site designee
- Refueling operations are in progress on Unit 2. One of the Startup Channels is out of service. Can fuel movement continue?
If one of the two Startup Channels R-005/006 are out of service, Then one of the Appendix R channels can be used in lieu of the Startup Channel as follows:
Ch 1 RE-005 can be replaced with RE-26-80B
Ch 2 RE-006 can be replaced with RE-26-80A
Unit 2 is shutdown for refueling with a full core off-load. How many fuel assemblies can be offloaded per hour?
What is the definition of ‘recently irradiated fuel’?
Recently irradiated fuel is defined as fuel that has occupied part of a critical reactor core within the previous 72 hours.
What is the sequence for removing SG manways and installing the nozzle dams? Why?
CAUTION
To prevent RCS pressurization and loss of inventory in the event SDC becomes inoperable, an adequate hot leg vent path shall be established and steam generator cold leg nozzle dams installed prior to the installation of the hot leg nozzle dams. Steam Generator primary side manway and nozzle dam installation / removal is performed in the following sequence per 2-PMM-01.05, Unit 2 Steam Generator Primary Side Maintenance:
Hot leg manways shall be removed prior to cold leg manways.
Cold leg nozzle dams shall be installed prior to hot leg nozzle dams.
Hot leg nozzle dams shall be removed prior to cold leg nozzle dams.
Cold leg manways shall be installed prior to hot leg manways
Primary manway and nozzle dam installation / removal may occur in any order with the reactor defueled and the temporary reactor head is installed.
When is the Containment Open Penetration Log used?
ESTABLISH and MAINTAIN an Open Penetration Log
(Attachment 4, CONTAINMENT OPEN PENETRATION LOG) throughout the refueling outage until post refueling fill and vent has been performed.
- What actions are required for Open Containment Penetrations if:
a. RCS Time to Boil < 30 min
b. RCS Time to Boil > 30 min
NOTE
When RCS time to boil (TTB) is less than 30 minutes, dedicated personnel are required for all OPEN penetrations and penetration closure should occur promptly and in all cases prior to the calculated time to boil as determined by 2-AOP-03.02, Shutdown Cooling Abnormal Operations.
When the RCS time to boil (TTB) is greater than 30 minutes, penetration closure time is required to occur promptly, and in all cases within the following times:
If RCS pressure boundary can be reestablished by dedicated personnel within the calculated time to boil, then the penetration closure time shall be less than two hours.
If RCS pressure boundary can NOT be reestablished within the calculated time to boil, then penetration closure time shall be the shorter of the following times:
Calculated time to boil as determined by 2-AOP-03.02, Shutdown Cooling Abnormal Operations
Less than two hours.
Tools necessary to close the penetration are required to be staged at the penetration.
Prior to performing refueling operations, the ‘Purge Mode Selector’ is placed in the REFUEL position. What does this do?
The suction side of the purge system is connected through a 48” by 48” duct containing damper DPR-25-5B to the containment cooling system ring duct header to assure uniform purging of the containment. A 36” by 14” branching duct from forty air inlets located above the water line in the refueling cavity is also connected to the purge system through damper DPR-25-5A. These air-operated dampers are controlled by the PURGE-REFUELING selector switch on RTGB 106 [HVCB]. DPR-25-5B is 100% open during PURGE and partially open when selected to REFUELING. DPR-25-5A is closed during PURGE and 100% open when selected to REFUELING. The refueling sequencing guidelines procedure provides guidance for the use of the switch.
What are the Technical Specification requirements for ‘Audible Countrate’ during Core Alterations?
To alert the operator of a boron dilution accident, at least one SRM must include audible indication in the control room to be considered OPERABLE.
Core reload is in progress. A nuclear instrument shows an increase in countrate. Can fuel movement continue?
NOTE
The instruction to stop core alterations if the count rate increases by a factor of two is NOT applicable when reloading the first four assemblies in the vicinity of each detector following a full core offload.
Typically, the first eight assemblies reloaded following a full core offload are twice-burned assemblies loaded in opposing dogears in the vicinity of the detectors used for count rate monitoring.
Initial loading of irradiated assemblies into an empty reactor vessel may cause the indicated count rate to increase by greater than a factor of two.
Reactor Engineering or Operations may renormalize base counts following loading of the first few fuel assemblies.
Core alterations shall be immediately stopped if count rate on any individual nuclear channel increases by a factor of two above base counts, except as noted above.
A reactor plant heatup IAW 2-GOP-504 is in progress. What is the maximum RCS heatup rate?
50°F in any one hour period
A reactor plant heatup IAW 2-GOP-504 is in progress. What is the maximum Pressurizer heatup rate and Pressurizer pressurization rate?
If RCS pressure is greater than 750 psia, then maximum RCS pressurization rate is 100 psi in any one hour period.
Preparations for a Unit 2 plant heatup are in progress. Prior to installing the pressurizer manway, we verify LTOP protection is in service. List three ways that we can meet this requirement.
Two SDC System relief valves
Two pressurizer PORVs
One PORV and one SDC System relief valve
Preparations for a Unit 1 plant heatup are in progress. Prior to installing the pressurizer manway, we verify LTOP protection is in service. How do we meet this requirement on Unit 1?
WHEN installing the Pressurizer Manway cover, THEN ENSURE overpressure protection is provided by at least one of the following:
A. The RCS is vented through an opening greater than 1.75 square inches by one of the following methods:
At least one Pressurizer safety valves is removed with opening NOT obstructed.
At least one PORV is removed with opening NOT obstructed.
B. ENSURE both of the following conditions are MET:
(1) Both Power Operated Relief Valves (PORVs) meet the
following:
A functional test of the actuation channels per 1-SMI-01.21, RCS Low Temperature Overpressure Protection (LTOP) Functional Test is complete.
PORV is OPERABLE
PORV is in service
PORV is selected to LOW RANGE
During 2-GOP_504, why do we limit the initial RCS heatup to < 185°F?
A maximum RCS temperature of 185ºF provides personnel protection during RCS Fill and Vent.
The optimum temperature band to perform RCS Fill and Vent on Unit 2 is 80°F to 185°F. Why?
The optimum RCS temperature range for performing fill and vent is between 60°F and 185°F.
RCS temperature of greater than 60°F allows the SDC Relief Valves to be isolated, which eliminates the possibility of a loss of RCS inventory in the event that RCS pressure increases to 350 psia during RCP runs.
RCS temperature of less than or equal to 185°F is for
personnel protection.
When performing a plant heatup from cold shutdown to NOP/NOT, approximately how much letdown water is produced?
The RCS heatup produces approximately two to three hold up tanks of letdown water.
Which is the preferred method for filling the RCS: LPSI pumps or charging pumps?
Filling with a LPSI pump is the preferred method if RCS chemistry (i.e., Silica) is NOT a concern.
If LPSI pump is used to fill the RCS, how is decay heat removal accomplished?
SDC Loop 2A would normally be used for filling RCS, while SDC Loop 2B is in service for decay heat removal.
What conditions must be true to stop SDC for 1 hour in Mode 5?
SDC may be stopped for up to 1 hour provided both of the following are met:
The RCS is NOT diluted
Core outlet temperature is maintained at least 10°F below saturation temperature
{ITS No draining operations to further reduce the RCS water volume are permitted.}
What is the limit on the RCS fill rate when performing RCS fill and vent with LPSI pumps on Unit 2?
Reactor Vessel Head and Pressurizer Vents have been orificed to 7/16”.
When filling with LPSI pump, flow greater than 500 GPM may result in inadequate venting.
If a LPSI pump is used to fill the RCS, how high will RCS pressure go when the RCS if filled?
RCS pressure will plateau when the LPSI Pump reaches shutoff head at approximately 180 psia.
If RCS was always maintained > Top of the Hot Leg since the last time RCS fill and vent was conducted, what’s the criteria that’s used to determine if RCP sweeps are necessary?
Criteria for bypassing RCP runs should be based on the amount of air released during venting:
Less than 1 minute time venting the Reactor Vessel Head.
How many RCPs are used when performing the initial RCS sweeps on Unit 2?
The first 30 second RCP runs are performed using one RCP in each loop. The second 30 second RCP runs should use the other two RCPs, however this is NOT required.
RCS heatup is in progress. How often is RCS heatup rate and RCS Boron Concentration determined?
RECORD RCS temperature every 30 minutes during heatup on 2-GOP-502, Data Sheets Required for Heatup, Reactor Coolant System Heatup Curve Data Sheet.
RECORD RCS boron concentration from chemistry sample every 50°F of RCS heatup on 2-GOP-502, Data Sheets Required for Heatup, RCS Boron Concentration During Temperature Changes Data Sheet.
What is the preferred start sequence for the first two RCPs started? Why?
The preferred RCP start sequence is starting RCPs 2B1 and 2B2 initially to provide better pressurizer spray flow.
What is the RCS pressure range for starting the preferred RCPs for plant heatup?
255-265 psia
How many charging pumps and HPSI pumps are required to go from Mode 5 to Mode 4 on Unit 2?
2-GOP-502 and TS
2 charging pumps
1 HPSI pump
What is the status of the ADVs and MSIVs on Unit 1 when making the transition from Mode 5 to Mode 4 on Unit 1?
ADVs full open each SG
MSIV and MSIV bypass valves closed each SG
When is H2 atmosphere normally established in VCT?
WHEN RCS temperature is greater than 250°F AND Chemistry permission is obtained, THEN ESTABLISH a hydrogen atmosphere in the VCT per 1-NOP-02.05, Volume Control Tank-Hydrogen and Nitrogen Concentration Control.
What is the expected RCP seal pressure breakdown?
RCP seal pressure breakdowns are expected to be approximately one-third of the differential between RCS and VCT pressure across each seal.
Why does the RCO monitor RCP lower seal cavity temperatures on the idle RCPs during a plant heatup?
RCP seal degradation can result from RCP lower seal cavity temperature exceeding 250F for extended durations.
When is the third RCP typically started during a plant heatup on Unit 2?
WHEN RCS pressure is above 350 psia, THEN START the third RCP per 2-NOP-01.02, Reactor Coolant Pump Operation.
NOTE
The third RCP start following RCS pressure rising above 350 psia is NOT mandatory.
Raising RCS pressure and temperature may be continued with two RCPs in operation.
Prior to raising RCS temperature to > 325°F, we verify that SG secondary temperature is > 100°F. What are two ways that this can be done per 1[2]-GOP-403?
VERIFY steam emitting from the ADVs
PERFORM the following.
(1) ESTABLISH blowdown from both Steam Generators per 2-NOP-23.02, Steam Generator Blowdown System Operations.
(2) MONITOR blowdown temperature on the DCS using the following points:
T23A, BLOWDOWN FLOW TEMP
T23B, BLOWDOWN FLOW TEMP
(3) WHEN blowdown temperature stabilizes, THEN
RECORD Steam Generator blowdown temperature as follows:
2A SG ______°F
2B SG ______°F
What is the approximate RCS pressure when the Letdown LCVs are placed in Single valve operation?
1400 psia
Why are the condensate pumps use as the SG feedwater source limited to RCS T < 450°F?
As RCS temperature approaches 450F, condensate pumps lose their ability to supply feedwater to the steam generators requiring feedwater to be placed in service for secondary plant feedwater inventory.
When are the Unit 2 Containment Spray Systems required to be operable?
Containment Spray System: MODES 1, 2, and MODE 3 with Pressurizer Pressure > 1750 psia.
What is the normal alignment for the Unit 2 SIT vent valves Modes 1,2,3 >1750 psia?
Safety Injection Tank vent valves normal alignment in MODES 1, 2 and 3 with RCS pressure above 1750 psia is CLOSED with power removed.
How many HPSI pumps are required to be operable in Mode 3?
It depends on RCS pressure.
< 1750 psia, then 1 HPSI pump
>1750 psia, then 2 HPSI pumps
Why is there a ‘Controlled Pressurization of Pressurizer Code Safeties’?
PORV and code Safety Valve leak by has occurred when the RCS is pressurized too rapidly from an RCS Cold condition.
What are the RCS temperature and pressure conditions for starting the fourth RCP?
RCS T > 500°F
RCS P > 1700 psia but < 1850 psia
Why is the amount of time operating with an idle RCP with RCS Pressure between 1700 psia and 1850 psia minimized?
CAUTION
All four RCPs are required to be in operation prior to exceeding 1850 psia RCS pressure.
The duration RCS pressure is greater than 1700 psia with an idle RCP should be minimized to maintain RCP seal temperatures between 250F and 299F.
