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Flashcards in Low Pressure Service Water System(RL) Deck (33)
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1
Q

What is the purpose of the Low Pressure Service Water System?

A
  1. Cooling and makeup water supply to various loads on the secondary side of the plant.
  2. Dilutes low level radioactive waste water.
  3. Provides discharge flow path for:
    A. Nuclear Service Water(RN)
    B. Cooling Tower Blowdown Water(RC), and draining
2
Q

What are the Low Pressure Service Water outside loads?

A
  1. Cooling Tower Makeup
  2. Containment Chilled Water Chillers(YV)
  3. Low Pressure Service Water Pump Motor Bearing Cooling Water
  4. Exterior Fire Protection Pump(RY) Motor Bearing Cooling Water
3
Q

What are the Low Pressure Service Water Turbine Building supplied loads?

A
  1. Generator Stator Heat Exchangers(KG)
  2. Generator Hydrogen Coolers(GH)
  3. Main Turbine Lube Oil Coolers(LT)
4
Q

What are the Low Pressure Service Water Service Building Supplied Loads?

A
  1. Recirculating Cooling Water Heat Exchangers(KR)
  2. Station Air Compressor Aftercoolers(VS)
  3. Fire Protection Jockey Pumps(RF)
  4. Service Building Chilled Water Chillers(YW)
5
Q

What is the system interrelation with Liquid Radwaste System(WL)?

A

The Low Pressure Service Water System provides dilution flow for liquid radwaste discharges, and provides the discharge path.

6
Q

What is the affect of losing Low Pressure Service Water flow on a Radwaste discharge?

A

The discharge is terminated when Low Pressure Service Water flow falls below a predetermined setpoint.

7
Q

What is the system interrelation with the Fire Protection System(RF)?

A
  1. If needed the RL system can supply suction to the RF Jockey Pumps.
  2. Also provides a discharge path for RF when used to cool E and F Instrument Air Compressors(VI) upon a loss of KR and/or RL.
8
Q

What is the system interrelation with the Condenser Circulating Cooling Water System(RC)?

A
  1. Provides makeup to the Cooling Towers of approximately 15Kgpm. One pump supplies the makeup for both units at full power.
  2. Provides a discharge path for Cooling Tower Blowdown Water.
9
Q

What is the system interrelation with the Nuclear Service Water System(RN)?

A

The Low Pressure Service Water system provides a discharge path for the Nuclear Service Water system.

10
Q

What is the purpose of the Turnaround Valves?

A

The Turnaround Valves provide minimum flow protection for the RL Pumps by maintaining header pressure at approximately 66psig.

11
Q

What is the failure position of the Turnaround Valves, and why?

A

The Turnaround Valves fail in the closed position to maintain supply header pressure for the loads on a loss of air.

12
Q

How do the Turnaround Valves work to control header pressure?

A
  1. The Turnaround Valves are controlled by a pressure sensor at the strainer inlet.
  2. There are three Turnaround Valves arranged in parallel. Pressure is controlled by bypassing flow
    to the discharge header.
  3. The three valves open sequentially based on the Control Room controller output.
13
Q

Where can the Turnaround Valves be operated manually?

A
  1. Control Room at 1MC-13

2. Locally

14
Q

What system provides the air for the Turnaround Valves, and what is available to ensure the valves fail in the correct position?

A
  1. The Instrument Air System provides the air for the valve operators.
  2. Pressurized air tanks assure the valves close to ensure cooling to major loads when Instrument Air is lost.
15
Q

How are the Turnaround Valves Manually operated using the valve handwheel?

A
  1. The holes in the valve actuator are aligned with the holes in the valve stem by turning the handwheel.
  2. With the holes aligned a pin is inserted through the holes.
  3. Turning the handwheel with the pins installed will turn the valve stem and position the valve.
16
Q

What is the purpose of the Intake Screens?

A

The Intake Screens prevent large objects from entering the suction of the RL pumps and possibly damaging the pumps, and if small enough to get through the pumps possibly damaging the discharge strainers.

17
Q

What is the design of the Intake Screens?

A
  1. Arranged as a continuous “belt”.
  2. One gear motor for each Intake Screen drives the screen to all the screen to be backwashed.
  3. The Intake Screen housing encloses a backwash spray header.
  4. Backwashed debris falls to a trench and is washed to basket which must be manually cleaned.
18
Q

Where can an Intake Screen backwash be initiated from?

A
  1. Control Room

2. Local Control Panel

19
Q

What will cause an automatic backwash of the Intake Screens?

A
  1. Every 8 hours,
    OR
  2. When differential level is greater than 6 inches of water.
20
Q

How many Intake Screens can be backwashed at once?

A

There is an interlock that allows only one Intake Screen to be backwashed at a time.

21
Q

Where is the water supplied from that is used to supply the Intake Screen backwash?

A

The backwash water is supplied from the outlet piping of the ‘B’ and ‘C’ RL pumps.

22
Q

How long does the Intake Screen rotate during a backwash cycle?

A

Approximately 10 minutes

23
Q

What is the basic flow path of an Intake Screen backwash?

A
  1. When the pressure sensors on the Intake Screen’s spray header sense adequate pressure(approx. 40psig) the screen motor is started for approximately 10 minutes.
  2. Water sprays on the traveling screen belt and trash flows to a trash basket.
  3. Normally the screen rotates at fast speed, but slow speed can be used for heavy deposits.
24
Q

What is the purpose of the RL Strainers?

A

The RL Strainers protected downstream pumps, valves, and loads by removing particles greater than 1/8 inch.

25
Q

Where can an RL Strainer backwash be initiated from?

A

Manually at the local control panel

26
Q

What conditions will cause an automatic backwash of the RL Strainers?

A
  1. Every 8 hours,
    OR
  2. When differential pressure is greater than 10psig
    Backwash continues for approximately 5 minutes after selecting OFF
27
Q

How many Low Pressure Service Water Pumps are there, and how many are normally in service?

A
  1. There are three RL pumps.

2. Two pumps are normally in service.

28
Q

What type of interlock is associated with the RL Pumps and their discharge valves?

A
  1. The discharge valve must be closed to start an RL pump.
  2. The discharge valve will start to open 6 seconds after a pump start.
  3. The discharge valve should be fully open 60 seconds after a pump start.
29
Q

Where is the Low Pressure Service Water Pump Motor Bearing cooling water supplied from?

A

RL pump motor bearing cooling water is supplied from the outlet of the strainer.

30
Q

What are the power supplies for the Low Pressure Service Water Pumps?

A
  1. A pump - 2TA
  2. B pump - 1TB
  3. C pump - 1TC
31
Q

What is the system designator for the Low Pressure Service Water System?

A

RL

32
Q

How are the RL Pumps shutdown?

A

Close the off-going pump discharge valve, and the pump will trip approximately 6 seconds after the discharge valve is fully closed.

33
Q

How are Asiatic Clams controlled in the RL system?

A
  1. Clams are captured using strainers that are either flushed or manually cleaned.
  2. Heat exchangers and pipes are manually cleaned to control clam buildup.

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