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26 Cards in this Set

  • Front
  • Back

Circulating Water Pump Trips

-Manual Control Room Control Switch

-Over Current

-Under Current on associated 4kV bus (55V)

Circulating Water Pumps Discharge Valves

-Auto Opens when associated pump AUTO Starts. Must be manually openend on manual start. (Prevents pump runout.)

-Auto Closes on associated pump breaker opening. (Prevents short cycling system.)

Circulating Water Pump Auto Start

-Control Room Switch in AUTO - the auto start on failure of a running pump.

Screen Functions

-When in Auto, Screens auto start on timer or differential level. (Increases speed with increasing D/P)

-25" H2O = max screen speed

-Starts on variable setpoint and runs until D/P is <4" for 5 seconds + 5 minutes

Circulating Water Pump Power Supplies

#11(21) - 1D(2D)

#12(22) - 1A(2A)

#13(23) - 1B(2B)

#24 - 4C

Circulating Water System Loads


-Main Condensers

-Feed Pump Condensers

-Radiological Liquid Waste

-Turbine Room Sump Overflow


-Chlorine Injection (xtie)

-Miscellaneous Sealing Cooling Water (xtie)

-Lawn Sprinkler System (xtie)

Circulating Water System Support

-Chlorine Injection

-Miscellaneous Seeling and Cooling Water(From NESW Now)

-Screen Wash System

-Vacuum Priming

De-Icing Flow Path

From a single unit discharge (WMO-16 or 26), through the de-ice tunnel and out the middle intake tunnel(WMO-30 is closed)

Close WMO-30

Open WMO-16 or 26

Throttle WMO-15 or 25A/B to control forebay temperature

Indications of Icing

-Circulating Water Temperatue <= 35F

-There is greater than one foot of drawdown in the forebay not caused by starting a pump.

-Traveling Screens high and/or extreme high differential pressure alarms are annunciating with little or no trash collection in the screen wash trash.

Circulating Water Pumps Operation should not occur below what elevation?

565 Feet which is the low low level setpoint

Forebay level monitoring

40 radar units monitor level

-One on East and West side of each screen(28 Total)

-12 Feed the control room recorder

WMO-17 & 27 function

They provide emergency suction source for ESW pumps in the event CW intake tunnels collapse.

Technical Specification 3.7.9

Ultimate Heat Sink must be operable and under 88.8F

Purpose of Circulating Water System

Safety Related Function - Provide water source to the essential service water system pumps. This is based on heat sink requirement.

Non-safety related -

-provide a heat sink for waste heat from the plant thermal cycle

-provides a water source to various systems and equipment

-support operation of the steam dump system

-provides dilution to perform a radioactive release.

Screen Wash System Purpose

-Remove fish and debris from traveling screens to maintain a water supply to the circulating water system

-Prevents screen damage due to excessive differential

Intake Cribs

Surround and support the flared upright intake elbow. A fish deterent system is mounted to intake crib ice guards.

Screen house Forebay and Bar grills

Provides structural support for the trash racks, travelling screens, circulating water pumps, esw pumps, and associated equipment. Trash racks prevent large objects from damaging the the traveling screens

Circulating Water Pumps

Provides head necessary to maintain circulating water flow. Bearing and packing cooling comes from miscellaneous seal cooling water.

Circulating Cross Tie Loads

Cross tie from U1 to U2 A condenser outlets

-Chlorination system

-Lawn Sprinkler

-Miscellaneous Sealing and cooling water System

Circulating Water System Loads

-Essential Service Water

-Non-Essential Service Water

-Miscellaneous Seal Cooling Water

-Feed Pump Condensers

-Main Condensers

-Lawn Sprinkler System


Loads that Circulating Water Discharges

-Essential Service Water

-Non-Essential Service Water

-Main Condenser outlets

-Feed Pump Condenser outlets

-Radwaste Release

-Turbine Room Sump Overflow

-Condensate Dumps

Vacuum Priming System

Removes Non-condesible gases from all of the heat exchangers and horizontal centrifugal pumps.

One pump runs on both units and rest on AUTO. Kick on as vacuum degrades (4 on Unit 1 and 5 on Unit 2)

If the System failed, tubes could become uncovered, cause reduced flow and reduced efficiency due to decreased vacuum.

Circulating Water Pump Switch

Four Position

-Trip- trips breaker open

-Neutral - disables auto feature

-Auto-allows pump to auto start on the falure of a running pump, and enables an interlock that operates associated discharge valve

-Close - closes breaker

Circulating Water Pump Discharge Valve Switch

Three Position

-Close - closes valve

-Pull-To-Stop - stops any travel,open or close, spring retrun to Pull-To-Stop position


Auto-Closes on pump breaker opening

Condenser Inlet/Outlet Valve Switch

Three position Switch

-Closes - Closes valve

-Pull-To-Stop - Stops travel, open or close

-Open - Opens Valve

Circulating Water Forebay Levels/Actions

578' Average Lake Level

565' Low Level Alarm

562' Extreme Low Level - Unit Shutdown Required & Stop All circulating Water Pumps