A. B. Hopkins Generating Station

A. B. Hopkins Generating Station

OPERATING PROCEDURE

Closed Cooling Water System
HOPKINS REPOWERING PROJECT
UNIT HP2A

A.B. Hopkins Generating StationClosed Cooling Water System

May 1 2014Operating Procedure Unit 2 HP2A

TABLE OF CONTENTS

SectionPage

1.0INTRODUCTION...... 1

1.1Purpose & Scope...... 1

1.2System Identification Scope Definition...... 2

1.2.1 System Flowpath...... 2

2.0SYSTEM STARTUP...... 2

2.1Preoperational Procedures...... 2

2.2Precautions and Limitations...... 2

2.3Closed Cooling Water System Block Flow Diagram...... 3

2.3.1 Closed Cooling System Startup...... 3

2.4Startup of the Closed Cooling Water Pumps...... 4

3.0System Normal Operation...... 5

3.1System Routine Checks...... 5

3.2Rotating the Closed Cooling Water Pumps...... 6

4.0SYSTEM SHUTDOWN...... 27

4.1Closed Cooling Water System Shutdown...... 7

4.2System Post Shutdown Checklist...... 7

4.2.1Short Term...... 7

4.2.2 Long Term...... 7

4.3System Test Operation...... 9

4.3.1Closed Cooling Water Pump Cold Test...... 9

5.0ALARM RESPONSE...... 11

5.1Summary of Alarms...... 11

6.0CHECKLIST AND TABLES...... 37

Table 1 - Power Supply Checklist...... 37

Table 2 - Prestart Valve Lineup Checklist...... 37

Table 3 - Local Indicating Instruments...... 38

Table 4 - Control Room Indicating Instruments...... 39

7.0References...... 42

DraftPage 1

A.B. Hopkins Generating StationClosed Cooling Water System

May 1 2014Operating Procedure Unit 2 HPA

1.0Introduction

1.1Purpose and Scope

The purpose of this operating procedure is to provide the operator with specific procedures for operating the Closed Cooling Water System. The operating procedures include those detailed procedures required to start-up, operate, and shutdown the system in a logical, efficient, and safe manner.

1.2System Identification and Scope Definition

The Closed Cooling Water System begins at the Expansion Tank and circulates water in a closed distribution system. Provisions are made to add water and chemicals to the expansion tank as necessary. During the closed distribution flow path the water receives heat from the equipment within the loop and dissipates the by means of a set plate exchangers. The system components are powered from the 480V HRSG MCC-1 and MCC-2.

2.0SYSTEM STARTUP

2.1Preoperational Procedures

2.1.1Prerequisites

1. The 480 VAC electrical distribution system is in service.
2. The compressed air system is in service.
3. The Demineralized water system is in service.
4. The Glycol feed system is ready for service.

2.1.2Prestart Requirements

1. All clearances are released and the equipment is in safe operating condition.
2. The power supply lineup is correct per Table 1.
3. The prestart valve lineup is correct per Table 2.
4. All system instrumentation is available per Tables 3 and 4.
5. Expansion tank has sufficient level to supply required NSPH
6. Closed Cooling Water within water quality limits.

2.2Precautions and Limitations

THE FOLLOWING PRECAUTIONS ARE SYSTEM SPECIFIC OPERATIONAL CONSIDERATIONS THAT MUST BE CLOSELY FOLLOWED. FAILURE TO FOLLOW THESE PRECAUTIONS MAY RESULT IN PERSONNEL INJURY OR EQUIPMENT DAMAGE.

1. The Expansion Tank level must be maintained at a level which ensures proper pump flooding.
2. The discharge pressure should be maintained at approximately 15 psig to ensure adequate flow through the exchangers.
3. The Closed Cooling Water Bypass Valve should maintain a minimum flow of 958 GPM through the CT Generator Cooler
4. To prevent thermal expansion of an enclosed fluid the isolation valves should always be open except during maintenance.

2.3Closed Cooling Water System Block Flow Diagram

2.3.1 Closed Cooling Water System Startup

2.4Startup of the Closed Cooling Water Pumps

ACTION / LOC / VERIFICATION
NOTE:
The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an L/P step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
1.VERIFY the Expansion Tank level is adequate.
If the Expansion Tank level is low, Demineralized Water can be added. / C / Level indicator WCLIT201 indicates 50% level in expansion tank
Control room indicator at 50% level in expansion tank.
.
2.OPEN Closed Cooling Water pumps suction valves, WC-1A and WC-1B. / L / Butterfly Valves indicates fully open
3 Ensure all manual inlet and outlet valves on the coolers through the distribution system are open and set to their normal running position. / L / Valves indicates fully open
4 Crack OPEN high point vent on discharge header to expel any trapped gas and ensure the system is hydrostatically filled. Closed Vent valve after gasses have been liberated. / L / Ensure the system is hydrostatically filled. Closed Vent valve after gasses have been liberated.
5.VERIFY oil level is adequate in motor upper bearings. / L / Local sight glass on motor.
6.VERIFY the Closed Cooling Water pumps seal water supply valve is open. / L / Ensure the pumps are hydrostatically filled. Closed Vent valve after gasses have been liberated
7. START the selected Closed Cooling Water Pump locally or at the DCS. / L / Butterfly Valves indicate one turn open.
8. SLOWLY OPEN Closed Cooling Water pump discharge valve WC-3A or WC-3B until fully open.
9.VERIFY the Closed Cooling Water pump bypass valve WC033 is maintaining a stable flow through the CT Generator Coolers and the remaining downstream coolers in the distribution system. / L/C / Local and control room closed cooling water pump discharge pressure indicators.
10.VERIFY Expansion level control WCLIT201.is maintaining level / L/C / Local and control room condenser level indicators.
11.PLACE the other Closed Cooling Water Pump in standby mode at the DCS board. / C / STANDBY indicating light is illuminated in the control room.
12. Inspect System to ensure integrity of piping and coolers in the distribution System / L

3.0SYSTEM NORMAL OPERATION

3.1 System Routine Checks

ACTION / LOC / VERIFICATION
NOTE:
The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an L/P step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE:Proper operation of plant equipment will lead to increased availability, sustained performance, and extended life of the equipment, while reducing the chance of failure. Proper operations include close adherence to operating procedures when starting the equipment, proper monitoring and inspections when the equipment is in normal operations, and following proper operating procedures when shutting down.
1.Check all indications listed in Table 3, Local Indicating Instruments. / L / Verify each is within the normal operating range.
2.Check all control room indications. / C / Verify all are operating normally.
3.Check the Expansion tank Level. / L / Verify adequate level and
overflow header
4.Check the Closed Cooling Water Pumps / L / Check suction strainers and discharge
pressure.
Check the lubrication oilers.
Check for signs of leakage.
Check motor/pump coupling.
Check for abnormal noises or vibration.
Monitor Bypass valve WCFCV033 operation.
5.Check the Plate Heat Exchangers for leaks / L / Check for leaks and differential
temperature
.
6.Check all coolers in the distribution system. / L / Check for signs of leakage.

3.2Rotating the Closed Cooling Water Pumps

ACTION / LOC / VERIFICATION
NOTE:
The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an L/P step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE:The closed cooling water pumps are rotated periodically to equalize pump/motor run time. This procedure places pump B in service and removes pump A from service.
1.VERIFY OPEN closed cooling water pump B suction valve, WC001B. / L / Butterfly Valve fully open.
2.VERIFY oil level is adequate to motor bearings. / L
4.OPEN the closed cooling water pump B discharge valve 1 turn, WC003B. / L / Butterfly Valve cracked open
6.START closed cooling water pump B locally or at the DCS. / L/C / Red ON indicating light is illuminated both in the control room and locally. Pump energizes and discharge pressure increases on pressure indicator WCPI204B
7.SLOWLY OPEN closed cooling water pump B discharge valve until fully open. / L / Butterfly Valve fully open
8.STOP closed cooling water pump A locally or at the DCS. / C/L / Green OFF indicating light is illuminated both in the control room and locally.
9.PLACE closed cooling water pump A in standby. / L

4.0 SYSTEM SHUTDOWN

4.1Closed Cooling Water System Shutdown

ACTION / LOC / VERIFICATION
NOTE:
The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an L/P step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
1.VERIFY the closed cooling water system is not required for service. / C / Coolers in the distribution loop no longer requires heat removal medium.
2.If a closed cooling water pump is in STANDBY mode, PLACE in OFF. / C / AMBER light goes out at DCS.
3.STOP the operating closed cooling water pump locally or at DCS. / C / Green OFF indicating light illuminates at the DCS and local switch.
4.VERIFY closed cooling water pump stops and pressure drops to 0 in on the distribution headers. / L / Local pressure indicators WCPI0204A & WCPI204B.

4.2System Post-Shutdown Checklist

When not required for operation, the closed cooling water system must be maintained in a layup condition to preserve its integrity and to prevent internal deterioration and contamination of the piping and components. The type of layup required is determined by the time period the system is estimated to be out of service. If it is estimated that the closed cooling water system is to be out of service less than three months, a short term layup must be performed. If three or more months are anticipated, a long term layup will be required.

4.2.1Short Term

A short term layup maintains the closed cooling water system in a state of readiness while ensuring the oxygen level of the closed cooling water is maintained below limits. During a short term layup, the closed cooling water is injected with a passivator and the closed cooling water pumps are operated weekly for a minimum of thirty minutes. During weekly pump operation, the bypass control valve WCFCV033 manual bypass valve is opened to recirculate flow back to the suction of the closed cooling water pumps. The Expansion Tank makeup regulator remains in service and are used to maintain the level. Samples are taken from the cycle and tested to ensure the passivator content is maintained at specified limits.

4.2.2 Long Term

A long term layup requires drainage of the distribution system and isolation of the surface condenser and steam turbine. Once isolated and drained, warm air is blown into the distribution system to purge all moisture and dry the internal surfaces

After a long term layup the System Test Operation (Section 5.4) should be performed prior to placing the closed cooling water system in service, per Section 2.0 of this procedure.

4.3System Test Operation

4.3.1 Closed Cooling Water Pump Cold Test

ACTION / LOC / VERIFICATION
NOTE: The LOC column in this procedure specifies where the associated ACTION step is taken. A "C" step is performed in the Control Room, an "L" step is performed locally, and an L/P step is performed at a local panel. A "C/L" or "L/C" step indicates a combination of Control Room and local activities.
NOTE:This procedure is to be performed prior to placing the closed cooling water pumps in service. This is a "cold" system test to provide a method of testing the automatic operations of the closed cooling water pumps.
1.VERIFY the Expansion Tank level is adequate.
NOTE: If the Expansion Tank level is low,demineralized water can be added to the tank. / L/C / Level controller WCLIT204 at 50%
.
2.OPEN the closed cooling water pump suction valves, WCC001A and WC001B. / L / Valve stems are retracted.
3.VERIFY oil level is adequate to the motor bearings. / L
4.OPEN the closed cooling water pump discharge valve 1 turn, WC003A or WC003B. / L / Butterfly Valves cracked open one round.
7.START the selected closed cooling water pump locally or at the DCS. / L/C / Red ON indicating light is illuminated both in the control room and locally. Pump energizes and discharge pressure increases on pressure indicator WCPI204A or WCPI204B.
8.SLOWLY OPEN closed cooling water pump discharge valve until fully open. / L
9.VERIFY the closed cooling water pump bypass valve WCFCV033 is maintaining flow. / L/C / Local and control room closed cooling water pump discharge pressure indicators.
11.PLACE the other closed cooling water pump in standby mode at the DCS / C / Amber STANDBY indicating light is illuminated in the control room.
13.STOP the operating closed cooling water pump locally or at the DSC. / L/C / Green OFF indicating light is illuminated both in the control room and locally. Pump de-energizes and discharge pressure decreases on pressure indicator WCPI204A or WCPI204B.
14.After pressure reaches XX psig VERIFY the STANDBY closed cooling water pump starts. / L/C / Red ON indicating light is illuminated both in the control room and locally. Pump energizes and discharge pressure increases on pressure indicator WCPI204A or WCPI204B.
15.VERIFY the closed cooling water pump bypass valve WCFCV033 is maintaining flow. / L/C / Local and control room closed cooling water pump discharge pressure indicators.
16.VERIFY Expansion Tank level control WCLIT201 is maintaining level. / L/C / Local and control room condenser level indicators.

5.0ALARM RESPONSES

5.1Summary of Alarms

ALARM CONDITIONS
Alarms / Initiating Device(s) / Device Setpoint(s)
Closed Cooling Water Pumps Common Suction Header Pressure Low / WCPT202
Expansion Tank Level High / WCLIT201
Expansion Tank Level Low / WCLIT201
Closed Cooling Water Pump A Suction Strainer
Differential Pressure / WCPDIT220A
Closed Cooling Water Pump B Suction Strainer
Differential Pressure / WCPDIT220B
Closed Cooling Water Pump A Motor Amps
Closed Cooling Water Pump B Motor Amps
Closed Cooling Water Pump A Motor Speed
Closed Cooling Water Pump B Motor Speed
Closed Cooling Water Pump Discharge Temperature / WCTE206
Closed Cooling Water Pump Discharge Flow / WCFE206
Closed Cooling Water Pumps Discharge Header Temperature / WCTE208
CT Generator Coolers Outlet Flow / WCFT221
CT Generator Coolers Outlet Temperature / WCTE211
LCI Coolers Outlet Flow / WCFE219
LCI Coolers Outlet Temperature / WCTE212
Gas Turbine Base Coolers Outlet Flow / WCFE218
Gas Turbine Base Coolers Outlet Temperature / WCTE213
LF/AA Cooler Outlet Flow / WCFE220
Accessory Module Coolers Outlet Temperature / WCTE214
Accessory Module Coolers Outlet Flow / WCFE217

Alarm: Closed Cooling Water Pump Suction Pressure Low

Initiating Device(s): WCPT202

Setpoint(s):

Possible Causes

Device failure

Expansion Tank Level low

Increased demand

Variable Frequency Drive Malfunction

Consequences

1. Loss of cooling to subsystems.

2.Exceed amperage rating on Close Cooling Water Pump

Immediate Operator Action

Verify Closed Cooling Water header pressure.

Verify Expansion Tank Level.

1)Verify valve position on outlet of coolers (Throttling Valves).

2)Notify Shift Supervisor.

Follow Up Operator Action

1.Reset alarm.

2.Verify Closed Cooling Water pump suction pressure

3.Inform Maintenance Department to check/repair/calibrate pressure switch if necessary.

Alarm: Closed Cooling Water Pump Suction Pressure HIGH

Initiating Device(s): WCPT202

Setpoint(s):

Possible Causes

Device Failure

Expansion Tank level high.

Suction Strainers Fouling

Coolers Restricted

Bypass valve WCFCV033 failed open

Consequences

1. Low discharge flow

2. Loss of cooling.

3. Increased temperature across coolers

Immediate Operator Action

Check Suction Strainer.

Verify suction header pressure.

Check Expansion Tank Level

Check WCFCV033 valve position

Check valve position on outlet of coolers (Throttling Valve).

Notify Shift Supervisor.

Follow Up Operator Action

1.Reset alarm.

2.Verify Closed Cooling Water pump suction pressure remains stable.

3.Inform Maintenance Department to check/repair/calibrate pressure switch if necessary.

Alarm: Expansion Tank Level High

Initiating Device(s): WCLIT201

Setpoint(s):

Possible Causes

Demineralized Water Makeup Regulator WCLCV201 fail open

Device malfunction

Glycol Fill Valve Open

Consequences

1. Increased suction header pressure

2. Overflow to waste.

3. Loss of Glycol to Demineralized water ratio mix

Immediate Operator Action

Verify Expansion Tank level.

Verify Makeup Regulator has modulated to the closed position.

Verify Expansion Tank level decreases.

Verify Glycol fill header is closed

Follow Up Operator Action

1. Reset alarm.

2. Verify Demineralized Water Makeup Regulator modulates to maintain Expansion Tank level.

3. Inform Maintenance to check/repair/calibrate Level Switch if necessary.

Alarm: Expansion Tank Level Low

Initiating Device(s): WCLIT201

Setpoint(s):

Possible Causes

Device malfunction

Demineralized water makeup regulator failure

Expansion Tank base drain valve open

Consequences

1. Cavitation of on line pump

2. Low discharge pressure

3. Condenser Makeup Regulator opens.

4. Loss of NPSH.

5. Loss of coolant to downstream subsystems

6. Loss of Closed Cooling Water System

Immediate Operator Action

Verify on line pump status

Verify Expansion Tank level.

Verify Makeup Regulator has modulated to the open position.

Verify coolers are receiving adequate flow.

Verify Base Drain valve is closed.

Follow Up Operator Action

1.Reset alarm

2.Verify demineralized water makeup regulator modulates to maintain the Expansion Tank level.

3.Inform Maintenance Department to check/repair/calibrate Level Switch if necessary.

Alarm: Closed Cooling Water Pump A Suction Strainer

Differential Pressure HIGH

Initiating Device(s): WCPDIT220A

Setpoint(s):

Possible Causes

Device malfunction

Suction strainers fouling.

Variable Frequency Drive Malfunction.

Bypass Control Valve WCFCV033 failed open.

Expansion Tank level HIGH

Consequences

1. Loss of coolant flow
2. Loss of Closed Cooling Water subsystems.

Immediate Operator Action

Verify Variable Frequency Drive status.

Verify Expansion Tank level

Check Pressure Differential Switch

Check Bypass Flow Control Valve WCFCV033.

Rotate Closed Cooling Water Pump If Strainer is fouled.

Notify Shift Supervisor.

Follow Up Operator Action

1.Reset alarm.

2.Verify differential pressure across strainer.

3.Inform Maintenance Department to check/repair/calibrate pressure switch if necessary.