Main Condensers Flashcards

1
Q

Describe the design of the main condensers

A
  • 3 vertical shells: 1 for each low pressure turbine
  • Main condenser water boxes are split so you can isolate 1 half for maintenance
  • unit 1 has equalizing ducts to avoid temp and pressure differences across bearings
  • unit 2 each shell is separate
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2
Q

What loads input in to the condensers

A
  • Turbine section
  • normal blowdown flashtank
  • MFP ELOS
  • makeup from cst
  • drip receivers
  • msr drain tank
  • hotwell pump suction and discharge vents
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3
Q

How does the hotwell level control system operate

A
  • Level controller references leg a or c differential pressure
  • 1 level controller controlls all hotwells
  • crv 155 opens to let down water
  • crv 55 opens to raise water level
  • on loss of reference leg
    • indicated level rises crv 155 opens actual level lowers, hotwell pump suction is challenged
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4
Q

How will a high level in the condenser hotwell affect the operation of the plant

A

Lowers vacuum because the high level reduces surface area for the heat transfer on the tubes

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5
Q

How will low hotwell level affect the operation of the plant

A
  • reduces NPSH to the hotwell pump allowing it to cavitate and potentially steam bind
  • if it causes low flow to the MFP suction the MFP will trip
    • this will require a reactor trip in Unit 2
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