General System Diagram of Palo Verde Nuclear Generating Station

General System Diagram of Palo Verde Nuclear Generating Station
PLANT STATUS! 8 CONTAINMENT SPRAY Equipment Cooling Polishing Demineralizers Condensate Pump General System Diagram of Palo Verde Nuclear Generating Station Generator LP Turbine HP MSSS Bldg. ADVs MSIV MSSVs Refueling Water Tank Containment Building Turbine Building Z MTSV MTCV Auxiliary Feedwater System Safety Injection Systems Legend:: Main Steam System Main Feedwater System Main Condensate System Circulating Water System Reactor Coolant System Auxiliary Spray Pump Low Pressure Safety Injection Pump High Pressure Safety Shutdown Heat Exchanger Safety Injection Steam Pressurizer Control Rods Reactor Core Coolant From Feedwater Pumps Regulation Valve Main Feedwater (HP) Heaters (LP) Main Condenser Moisture Separator Reheaters Bypass Valves Circulating Water Pump Cooling Tower and Fans Transformer To Switchyard Containment Sump PV Daily Status Report

IT’S OUR RESPONSIBILITY!
NUCLEAR SAFETY INDUSTRIAL SAFETY RADIOLOGICAL SAFETY SAFETY CULTURE

BALANCE OF PLANT ENGINEERED SAFETY FEATURE ACTUATION SYSTEM
COURSE/LESSON TERMINAL OBJECTIVE: GIVEN THE APPLICABLE REFERENCE MATERIALS, THE I&C TECHNICIAN WILL DESCRIBE THE DESIGN, OPERATION AND MAINTENANCE ON THE BALANCE OF PLANT ENGINEERED SAFETY FEATURES ACTUATION SYSTEM. PROFICIENCY WILL BE DEMONSTRATED BY ACHIEVEMENT OF AT LEAST 80% ON A WRITTEN EXAMINATION

Which of the following is not an actuation signal from BOP-ESFAS
FBEVAS CPIAS SIAS CRVIAS

Which BOP-ESFAS function is manual initiation only?
CPIAS CRVIAS DGSS LOP/LS

FBEVAS channel “A” is in bypass
FBEVAS channel “A” is in bypass. Manual initiation at B05 will not cause a FBEVAS. True False

All BOP-ESFAS relays are normally energized and will de-energize to actuate loads.
True False

Placing both A & B trains of CPIAS in bypass will cause:
Both trains to be bypassed CPIAS to be initiated Both trains to drop out of bypass “A” train only to be in bypass

ENABLING OBJECTIVES: EO01 STATE THE PURPOSE OF THE BALANCE OF PLANT ENGINEERED SAFETY FEATURES ACTUATION SYSTEM. EO02 DESCRIBE THE FUNCTIONS PERFORMED BY THE BALANCE OF PLANT ENGINEERED SAFETY FEATURES ACTUATION SYSTEM.

Purpose Provides continuous monitoring of selected plant variables
Actuates BOP ESF equipment when monitored parameters exceed setpoints Provides load sequencing necessary for proper ESF system operation VTM page 2-1

Minimizes the consequences of the following design base accidents:
BALANCE OF PLANT ENGINEERED SAFETY FEATURE ACTUATION SYSTEM Minimizes the consequences of the following design base accidents: Fuel Handling Fire/Smoke (manual actuation only) Loss of Power

OUTPUTS? INPUTS? BIG PICTURE Overview BOP ESFAS CREFAS FBEVAS CPIAS
Rad Monitors CPIAS Voltage Monitors CRVIAS PPS ESFAS Loss of Power Manual Load Shed ESF Load Sequencer Equip Start Diesel Start 120 Vac (PN) 125 Vdc (PK)

EO03 DESCRIBE THE BALANCE OF PLANT ENGINEERED SAFETY FEATURES ACTUATION SYSTEM TO INCLUDE MAJOR COMPONENTS, LOCATION OF PRINCIPAL UNIT AND SOURCES OF POWER. EO04 IDENTIFY THE LOCATION, CONTROLS, INPUTS, AND OUTPUTS OF THE BOP ESFAS CHANNEL POWER SUPPLY.

How are the cabinets cooled? The Cabinets
Each cabinet receives power from… Power is distributed… How are the cabinets cooled? 120 Vac 125 Vdc Cooling Fan Cooling Fan AC/DC Converter DC/DC Converter 28 VDC Bus

28 VDC 27.75 VDC Monitors P/S temperature and output
Rejects or further suppresses transient line voltages SAFETY FEATURES OVER VOLTAGE OVER CURRENT HIGH TEMPERATURE Each Power Supply is equipped with internal fans 120 VAC Vital Power (PNA-D25/PNB-D26) 28 VDC LOW PASS FILTER-rejects high freq noise and transients Monitors P/S temperature and output 125 VDC Vital Power (PKA-D21/PKB-D22) AUCTIONEERING DIODES Remote Light Remote Light and alarm Remote Light 27.75 VDC

EO05 DESCRIBE THE OPERATION OF THE CONTROLS LOCATED ON THE KEY LOCK SWITCH PANEL. EO06 IDENTIFY THE LOCATION AND FUNCTION OF THE ISOLATOR ASSEMBLY. EO07 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE FBEVAS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS.

Keylock Switch Panel Located in the A4 assembly of each cabinet.
Keylock bypass switches provided for all module inputs EXCEPT DGSS and Load Sequencer. Bypasses are interlocked so same parameter cannot be bypassed in both trains at the same time.

Bypass Inhibit U34: Normal = High Bypass = Low Inhibit
U20: Normal = Low Bypass = High U15: High output required for actuation  bypass inhibit always forces U15 High (NAND logic)

Isolator Assembly Located in the A5 assembly
18 optical isolators on a single board Photodiode optically coupled to a phototransistor Isolate communication between logic trains “A” and “B” Page 9 of printbook

Example: Page 10 of printbook
VTD-G

Fuel Building Essential Ventilation Actuation Signal (FBEVAS)
BOP ESFAS provides initiating signals to components requiring automatic actuation whenever monitored variables reach levels that require protective action. The actuations that originate from the BOP ESFAS include the following: Fuel Building Essential Ventilation Actuation Signal (FBEVAS) Containment Purge Isolation Actuation Signal (CPIAS) Control Room Ventilation Isolation Actuation Signal (CRVIAS) Control Room Essential Filtration Actuation Signal (CREFAS). Loss of Power/Load Shed (LOP/LS) Diesel Generator Start Signal (DGSS) Sequencer Output Signals

Safety System Functions
Fuel Building Essential Ventilation Actuation Signal (FBEVAS): FBEVAS operates two redundant filter trains whenever 1 of 2 high radiation signals are received and maintains negative pressure in the Fuel Building to prevent leakage of unfiltered air to the environment in the event of a fuel handling accident

Essential Exhaust Dampers OPEN and Essential AFUs START
These actions cause the Fuel Bldg Essential AFUs to start and take a suction of the Fuel Bldg. What if a SIAS and a FBEVAS occur concurrently? Essential Exhaust Dampers OPEN and Essential AFUs START …and Exhaust dampers CLOSE Norm Supply and Exhaust Fans STOP Norm Supply…

Signal enters BOP ESFAS Signal passes first “OR” gate. Signal passes second “OR” gate. Signal is then applied to the “AND” gate. RU-31 HIGH What does this do?

RU-31 CLEARS How do I clear it? What happens to the signal?

What does the Test Pushbutton do?

This goes away as soon as I release the pushbutton
How do I clear this signal? I still need to reset at the cabinet

This “AND” Gate blocks the signal from passing
Now RU-31 alarms Let’s take a look at the BYPASS.

Operations then bypasses RU-145.
WHAT HAPPENS? I&C is testing RU-31 with the channel in bypass. Here is a scenario…

NOTICE – RU-145 is never bypassed

Pushbutton on BOP ESFAS Cabinet is used.
Signal is sealed in, just like before. I need to break the seal in to clear. I now release the switch. What happens when I take the Channel “A” switch to actuate? Let’s look at the B05 Controls.

The system returns to “normal” as I release the pushbutton

Here is the BYPASS Switch

FBEVAS Module

TRIP RESET ACTUATE MAN RST TEST BYPASS

EO08 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE CPIAS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS. EO09 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE CREFAS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS.

Containment Purge Isolation Actuation Signal (CPIAS): CPIAS stops either a Power Access or Refueling Purge by closing inlets and outlets in the event of 1 of 2 high radiation signals. It thus minimizes offsite dose in event of a fuel handling accident in containment

These actions will also occur upon a CIAS.
Access Purge Downstream UV-5A/5B CLOSE Refuel Purge Upstream UV-2A/2B CLOSE Access Purge Upstream UV-4A/4B CLOSE Refuel Purge Downstream UV-3A/3B CLOSE The Purge Supply and Exhaust Fans are interlocked with their respective containment isolation dampers causing these fans to trip when the dampers isolate. These actions will also occur upon a CIAS.

WHAT’S DIFFERENT?

Tech Spec 3.3.8 CPIAS One CPIAS shall be operable
During modes 1-4, core alts or fuel movement in containment If not, shut down and close containment purge Minimizes offsite dose in event of a fuel handling accident in containment

Control Room Essential Filtration Actuation Signal (CREFAS): Actuated by 1 of 2 Control Room air intake high airborne activity signals, FBEVAS, or CPIAS. It thus minimizes dose to Control Room operators by isolating the normal ventilation and activating the charcoal filter system

HJA-M58 HJB-M10 HJA-M59 HJB-M13 HJA-M02 HJB-M02 HJA-M03 HJB-M03 HJA-M52 HJB-M55 HJA-M01 HJB-M01

Normal Only highlighting Train A components to avoid confusion

CREFAS Only highlighting Train A components to avoid confusion

These inputs are coming into the circuit
WHAT’S DIFFERENT?

Tech Spec 3.3.9 CREFAS One CREFAS shall be operable
During modes 1-6 and during fuel movement Or place one CREFS in operation

EO10 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE CRVIAS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS. EO11 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE LOP/LS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS.

Control Room Ventilation Isolation Actuation Signal (CRVIAS): CRVIAS is actuated manually by Control Room operators upon smoke alarm from outside air intake plenum. The chlorine detector automatic actuation is deleted. This signal isolates the normal and ENGINEERED ventilation for the Control Room

System was set up for two inputs (each having 2 trains)
This looks very different, but at a closer look…

CRVIAS Module

What happens on a CRVIAS?
Normal Ventilation Dampers CLOSE, CR Ess AHU A and B Outside Air Intake Dampers CLOSE, Condensate Transfer Pump A and B STARTS, CR Ess AHU Fans START, Essential Cooling Water START, Spray Pond pumps START, Essential Chillers START. CRVIAS will override the Outside Air Damper Open signal from SIAS or CREFAS. The damper will be closed by the CRVIAS.

Dampers CLOSE HJA-M58 HJB-M10 HJA-M59 HJB-M13 HJA-M02 HJB-M02 HJA-M03

Loss of Power/ Load Shed (LOP/LS): LOP/LS is actuated by 2 of 4 undervoltage relays on 4.16 KV bus. The 1 second Load Shed pulse causes a shed of the 4.16 KV loads and selected 480 V loads and opens 4.16 KV preferred offsite supply breakers. The 60 second off-delay LOP actuates forced shutdown loads

Loss Of Power (LOP)/Load Shed (LS)
Degraded Voltage PBA-S03 Degraded Voltage Relay Degraded Voltage Relay Degraded Voltage Relay Degraded Voltage Relay 4 solid state degraded voltage relays monitor PBA-S03 and PBB-S04. Four solid state degraded voltage relays and four undervoltage relays with inverse time characteristics are provided on each 4.16 kV Class IE bus for the purpose of detecting a sustained undervoltage condition or a loss of bus voltage. The Loss of Voltage (LOV) relays actuate if the voltage is below 70% for a short time or below 78% for a longer time. The Degraded Voltage (DV) relays activate if voltage is below 90% for a long time. The BOP ESFAS Loss of Power / Load Shed module receives inputs from the LOV and DV relays. The LOP/LS module has four channels with each channel having one LOV and DV input. If either a LOV or DV signal is received, that channel will trip. If any 2 of the 4 channels trip, a signal is sent to the BOP ESFAS Diesel Generator Start Signal (DGSS) module resulting in a start of the diesel. 2 of the 4 channels sense degraded voltage condition… trip signal sent to the DGSS module. Relays need power to operate! Receive 125 Vdc from PKA (PKB) Relay set at approximately 89% to 91% of normal voltage.

Loss of Voltage PBB-S04 Under Voltage Relay Under Voltage Relay Under Voltage Relay Under Voltage Relay 4 under voltage relays monitor PBA-S03 and PBB-S04. Four solid state degraded voltage relays and four undervoltage relays with inverse time characteristics are provided on each 4.16 kV Class IE bus for the purpose of detecting a sustained undervoltage condition or a loss of bus voltage. The Loss of Voltage (LOV) relays actuate if the voltage is below 70% for a short time or below 78% for a longer time. The Degraded Voltage (DV) relays activate if voltage is below 90% for a long time. The BOP ESFAS Loss of Power / Load Shed module receives inputs from the LOV and DV relays. The LOP/LS module has four channels with each channel having one LOV and DV input. If either a LOV or DV signal is received, that channel will trip. If any 2 of the 4 channels trip, a signal is sent to the BOP ESFAS Diesel Generator Start Signal (DGSS) module resulting in a start of the diesel. 2 of the 4 channels sense loss of voltage condition… trip signal sent to the DGSS module. Relay set at approximately 70% to 78% of normal voltage.

Loss of Voltage time delay IS! The lower the voltage level, the shorter the time delay! Degraded Voltage time delay is NOT impacted by voltage level! Here is a way to look at the Tech Spec setpoints... Relay must actuate between 28.6 and 35 seconds Relay must actuate between 10.3 and 12.6 seconds at Vac... Relay must actuate between 2.0 and 2.4 seconds at 0 Vac... 3697 Vac Vac 3786 Vac LOV Degraded 0 Vac 4160 Vac

What is so bad about degraded voltage? What can we say about the power to this load? LOW VOLTAGE 4160 Vac Four solid state degraded voltage relays and four undervoltage relays with inverse time characteristics are provided on each 4.16 kV Class IE bus for the purpose of detecting a sustained undervoltage condition or a loss of bus voltage. The Loss of Voltage (LOV) relays actuate if the voltage is below 70% for a short time or below 78% for a longer time. The Degraded Voltage (DV) relays activate if voltage is below 90% for a long time. The BOP ESFAS Loss of Power / Load Shed module receives inputs from the LOV and DV relays. The LOP/LS module has four channels with each channel having one LOV and DV input. If either a LOV or DV signal is received, that channel will trip. If any 2 of the 4 channels trip, a signal is sent to the BOP ESFAS Diesel Generator Start Signal (DGSS) module resulting in a start of the diesel. 480 Vac 480 Vac Load

What happens on an actuation? LOP/LS module sends the LOP signal to the DGSS module and also initiates load shed actuation. A 1 second load shed pulse is sent to selected loads to trip them as part of the load shed scheme. The DGSS module will start the Emergency Diesel Generator which will close in and energize the associated essential 4.16 kV bus. Four solid state degraded voltage relays and four undervoltage relays with inverse time characteristics are provided on each 4.16 kV Class IE bus for the purpose of detecting a sustained undervoltage condition or a loss of bus voltage. The Loss of Voltage (LOV) relays actuate if the voltage is below 70% for a short time or below 78% for a longer time. The Degraded Voltage (DV) relays activate if voltage is below 90% for a long time. The BOP ESFAS Loss of Power / Load Shed module receives inputs from the LOV and DV relays. The LOP/LS module has four channels with each channel having one LOV and DV input. If either a LOV or DV signal is received, that channel will trip. If any 2 of the 4 channels trip, a signal is sent to the BOP ESFAS Diesel Generator Start Signal (DGSS) module resulting in a start of the diesel. The DG Output Breaker closes automatically based on the LOP

When a D/G energizes its essential 4.16 kV bus, the associated LOV/DV relays are reset. What happens to the LOP signal??? The LOP/LS module maintains a LOP signal for 60 seconds from the time the essential bus is re-energized. This ensures the Load Sequencer finishes sequencing on the necessary loads for a LOP. Four solid state degraded voltage relays and four undervoltage relays with inverse time characteristics are provided on each 4.16 kV Class IE bus for the purpose of detecting a sustained undervoltage condition or a loss of bus voltage. The Loss of Voltage (LOV) relays actuate if the voltage is below 70% for a short time or below 78% for a longer time. The Degraded Voltage (DV) relays activate if voltage is below 90% for a long time. The BOP ESFAS Loss of Power / Load Shed module receives inputs from the LOV and DV relays. The LOP/LS module has four channels with each channel having one LOV and DV input. If either a LOV or DV signal is received, that channel will trip. If any 2 of the 4 channels trip, a signal is sent to the BOP ESFAS Diesel Generator Start Signal (DGSS) module resulting in a start of the diesel.

EO12 STATE THE FUNCTION AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE DGSS MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS. EO13 STATE THE FUNCTIONS AND DESCRIBE THE CONSTRUCTION AND OPERATION OF THE LOAD SEQUENCER/AUTO TEST MODULE, TO INCLUDE INPUTS, OUTPUTS, TEST FEATURES, CONTROLS, AND INDICATIONS.

Diesel Generator Start Signal (DGSS): Actuated by AFAS-1 or AFAS-2, SIAS/CSAS, or LOP signals, the DGSS starts the Diesel Generator and the DG Exhaust System

DGSS sends start signal to Diesel Generator AFAS-1 and AFAS-2 SIAS signal LOP Diesel status is communicated back to the Load Sequencer

3.3.7 Diesel Generator (DG) - Loss of Voltage Start (LOVS)

Load Sequencer/Auto Test: The Load Sequence is actuated by: LOP SIAS CSAS AFAS DG run CREFAS, CRVIAS, or FBEVAS It generates sequential timed start and permissive signals to ESF and forced shutdown system fans, pumps, and chillers. It does not operate valves or dampers. It auto tests each module every 22 seconds when in Auto Test

ESF Load Sequencer What does it do for us?
Receives a number of inputs and based on these inputs, decides which mode of operation to place BOP ESFAS in. The mode of operation will determine what equipment is started.

ESF Load Sequencer Devices which are sequentially actuated through the Load Sequencer receive a load shed signal on bus under-voltage to trip the device load...and a load sequencer start signal to start the device at the appropriate time. Reset of the Load Sequencer and its actuation relays does not stop or shed actuated devices.

ESF Load Sequencer Devices are shed only on the load shed signal.
If LOP is input, sequencer sends signals back to LOP/LS module. These signals are a 1 second load shed pulse and a 60 second off- delay LOP drive. (Keeps LOP signal active for 60 seconds after the D/G has re- energized the bus.)

MODE 1 SIAS/CSAS (No LOP) MODE 2 SIAS/CSAS/LOP DG Bkr Closed MODE 0 No input Standby Operation MODE 3 LOP Only DG Bkr Closed MODE 4 Everything else

Time 1 minute… Now a LOP occurs, what mode? Time 0… SIAS occurs, what mode?

Does it stay in Mode 2?

SIAS is reset… what happens?

You take the DG off the bus. What mode?

You shutdown the DG. What mode?

MODE 1 TIMING DIAGRAM: SIAS CSAS LOP DG BKR
TIME (SECONDS) 5 10 15 20 25 30 40 50 60 HPSI PUMP START 5 LPSI PUMP START 5 DIESEL GEN. ESS. EXHAUST FAN START 5 CONTROL ROOM ESS. AHU START 5 FUEL BLDG ESS. EXHAUST AFU START 10 AUX FEEDWATER PUMP START 15 CONTAINMENT SPRAY PUMP START 20 ESS. COOLING WATER PUMP START 25 FUEL BLDG ESS. EXHAUST AFU START 25 ESS. SPRAY POND PUMP START 30 ESS. CHILLER PUMP START 40 CHARGING PUMP START PERM. (UNBLOCKED)

MODE 2 TIMING DIAGRAM: SIAS CSAS LOP DG BKR
TIME (SECONDS) 5 10 15 20 25 30 40 50 60 0.5 HPSI PUMP START 0.5 480 LOAD CENTER 5 LPSI PUMP START 5 FUEL BLDG ESS. EXHAUST AFU START 5 CONTROL ROOM ESS. AHU START 5 BATTERY CHARGER START 5 DIESEL GEN. ESS. EXHAUST FAN START 10 AUX FEEDWATER PUMP START 15 CONTAINMENT SPRAY PUMP START 20 ESS. COOLING WATER PUMP START 25 ESS. SPRAY POND PUMP START 30 ESS. CHILLER PUMP START 40 CHARGING PUMP START PERM.

MODE 3 TIMING DIAGRAM: SIAS CSAS LOP DG BKR AUX FEEDWATER PUMP START
TIME (SECONDS) 5 10 15 20 25 30 40 50 60 0.5 480 LOAD CENTER 5 CONTROL ROOM ESS. AHU START 5 BATTERY CHARGER START 5 CONTROL ROOM NORMAL 5 DIESEL GEN. ESS. EXHAUST FAN START 10 AUX FEEDWATER PUMP START 20 ESS. COOLING WATER PUMP START 25 ESS. SPRAY POND PUMP START 30 ESS. CHILLER PUMP START 55 CEDM NORMAL

MODE 4A TIMING DIAGRAM: SIAS CSAS LOP (AFAS-1 OR AFAS-2)
TIME (SECONDS) 5 10 15 20 25 30 40 50 60 AUX FEEDWATER PUMP START 20 ESS. COOLING WATER PUMP START 25 ESS. SPRAY POND PUMP START 30 ESS. CHILLER PUMP START MODE 4B TIMING DIAGRAM: SIAS CSAS LOP (CREFAS OR CRVIAS) TIME (SECONDS) 5 10 15 20 25 30 40 50 60 5 CONTROL ROOM ESS. AHU START 20 ESS. COOLING WATER PUMP START 25 ESS. SPRAY POND PUMP START 30 ESS. CHILLER PUMP START

MODE 4C TIMING DIAGRAM: SIAS CSAS LOP (FBEVAS)
TIME (SECONDS) 5 10 15 20 25 30 40 50 60 Fuel Bldg Ess. Exhaust AFU MODE 4D TIMING DIAGRAM: SIAS CSAS LOP (DG RUN) TIME (SECONDS) 5 10 15 20 25 30 40 50 60 5 DIESEL GEN. ESS. EXHAUST FAN START 25 ESS. SPRAY POND PUMP

Sequencer Testing Sequencer polls each module in BOP ESFAS cabinet one at a time by sending a pulse to the module. The module then processes the test input and sends a return signal to the sequencer.

Sequencer Testing If the sequencer does not receive the proper test return signal, auto test stops and the affected module’s "TEST" light will flash. The other train will indicate a stall in the opposite train and cause the “STALL OPPOSITE TRAIN” annunciator to alarm. BOP ESFAS TEMP HI PWR SPLY/ AUTO TEST FAIL

EO14 Describe the use of Prevent Event Tools and Electrical Safe Work Practices to minimize human performance errors during testing or maintenance of the BOP ESFAS. EO15 Given examples of BOP ESFAS maintenance problems, determine the fault using applicable BOP ESFAS prints, Tech Manuals, and applicable documents.

Troubleshooting Scenario #1
You are at the step to bypass CPIAS Train “A” in accordance with the BOP ESFAS functional test (36MT-9SA01). You turn the key clockwise ¼ turn at the CPIAS Train “A” module, the BYPASS annunciator on the module is lit. You check the control room and observe the plant annunciator window 5A03D (BOP ESFAS CH BYP) is not lit. What actions do you take? What could be the problem? STAR – Notify team leader. Verify indications and procedural compliance. Possible causes – switch did cause plant annunciator to come in, therefore we should be in bypass. Possible module annunciator light out. Lamp test is performed several times in this procedure and can be performed again to verify. Refer to J-RKN-C01 prints and J Bypass annunciator is actuated from relay K5.

Troubleshooting Scenario #2
Plant is Mode 1, 100% power. A “HI CR RAD CH TRIP” (Window 5A04C) is received in the control room (CR) and Train “B” CREFAS module has both TRIP and ACTUATE annunciators lit. The following occurs: CR Ess AHU damper opens (M-HJB-M02) CR Normal AHU isolation dampers close Comm equipment isolation dampers close CR Ess isolation dampers close CR toilet and kitchen exhaust isolation dampers close OPS reports that the Condensate Transfer Pump did not start and the M-HJB-M03 damper did not open. Cross train “A” CREFAS was actuated. What actions do you take? What could be the problem? STAR Refer to 13-J-SAS Relay K122 causes condt xfer pump to start, so possible bad relay.

General System Diagram of Palo Verde Nuclear Generating Station

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