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.