Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

37 Cards in this Set

  • Front
  • Back

What are the safety related functions of the Main Steam System?

1. Provide steam to the TDAFP.

2. Control plant cool down rate during SBO with PORVs.

3. Allow rapid RCS cool down following SGTR.

4. Provide isolation capability following HELB.

What two SGs provide steam to the TDAFP?

2 & 3

What are the non-safety related loads on the MSS?

1. Main Turbine

2. Main Feedpump Turbines

3. Steam Dump System

4. Heating Steam to Reheaters

5. Aux Steam System

6. Steam Seals (U2 only)

What are the two purposes of the venturi flow restrictors coming off the SGs?

1. Reduce steam flow rate following SLB, reduces cool down rate of the RCS.

2. Contributes to pressure differential in steam flow measurement (SGWLC).

What ensures main steam pressure is limited to 110% of design pressure (1085 psig)?

Main Steam Safety Valves

What are the set points of the MS Safeties?

SV1 (A&B) 1065 psia

SV2 (A&B) 1075 psia

SV3 1085 psia

MRV 213, 223, 233, & 243 prevent _____ and allow____?

Lifting of the safeties

controlled plant cooldown

What is the PORV response to a loss of control power or air?

Fail closed

What is the lifting set point of the PORVs?

1025 psig

What 4 ways can the PORVs be operated?

1. CR

2. Hot shutdown panel

3. Local Control Station

a. Remote - air from HSD Panel

b. Local - overrides control from CR and HSD Panel.

4. Manually on each valve

Each PORV has an upstream manual isolation valve. If this isolation is closed, what action must be taken?

Enter the LCO for inoperable PORV Rad Monitor.

MRV-210, 220, 230, & 240 ensure only one SG will blowdown in a steam line rupture, what are two purposes of the Steam Generator Stop Valves?

1. Minimize positive reactivity effects of the RCS cool down to prevent fuel damage.

2. Limit containment pressure should the steam line rupture occur inside.

What are the three valves associated with the SGSVs that control fast closing?

One normally open 3-way MMO, two normally closed MRVs (dump valves).

What does the neon light out indicated located above the SGSV MRVs?

No solenoid power.

What is the purpose of the SGSV MMO?

Allows testing of the dump valves by isolating either MRV without tripping the SGSV closed.

What happens to the MRV on a loss of control air?

The MRV fails open, which vents air off the SGSV and closes it.

What happens to the SGSV components on a loss of power?

The solenoid remains de-energized, keeping air to the MRVs. The MRVs remain closed and the SGSV stays open. Fast closure capability is lost.

What happens to the SGSV on a loss of hydraulics?

The SGSV fails as is.

What is the purpose of the MRV LOCKOUT position?

Closes and electrically blocks the dump valve closed. Annunciator 117 alarm comes in. Must take the switch to TRIP/RESET and then to NEUTRAL to reset.

What are the conditions that result in a Steam Line Isolation (SLI) signal?

1. Manual

2. Containment pressure HI HI - 2.8 psig

3. High Steam Line Flow with P-12 (LO LO Tavg)

4. Lo Steam Line Pressure - 500 psi

What does the Turbine Bypass Equalizing Header supply?

1. High Pressure Turbine

2. East and West MFW Pump Turbines

3. East and West Steam Bypass Headers

What is the purpose of the main steam system drains?

Drain piping low points to prevent condensate accumulation, turbine damage, and steam line water hammer.

What is the response to a loss of control power or air to the main steam system drains?

DRV-407, SGSV drains, fail closed - all other MSS air operated drains fail open.

What would cause DRV-407 to automatically open?

Hi level in the SGSV drain pot in AUTO.

What would cause the Main Steam Lead, Turbine Bypass Equalizing Header, and Turbine Steam Lead Drains to automatically open?

Turbine Trip

Operability of the TDAFP requires what position of MCM-221 & 231, motor operated valve steam supply valves from the 2 & 3 SGs.

Both valves must be open.

What is the purpose of the TDAFP?

Ensures the RCS can be cooled down to less than 350 F from normal operating conditions in the event of a total loss of offsite power.

What is the purpose of the Steam Dump System?

Control RCS temperature less than 15% load, cool down, and maintain hot standby.

If the Steam Dump System is lost, what option do we have to remove heat from the RCS?

Use of the SG PORVs to the atmosphere.

The Aux. Steam System supplies steam to the following:

1. Turbine Sealing Steam (U1)


3. Feed Pumps

4. Plant Heating

5. Aux. Building - Vents & NBAE

6. Chemical Cleaning

7. Hotwell Deaerating (U2)

8. Fire Protection CO2 vaporizers

What would happen to the Main Feedwater Pumps on a loss of Aux. Steam?

Loss of vacuum for the pumps and condenser resulting in a plant trip.

What would the condition of the PORVs be following a loss of control air?

PORVs would be inoperable, however, would still be available via a back up nitrogen supply.

CCRP-3 supplies power to what PORV component?

Rad monitors 1600 (2600) & 1700 (2700) - data is lost following loss of power and battery depletion.

CRID-1 and -2 supply what?

PORV controllers - fail closed on loss of power.

Where are the main steam flows (MFC-110, 111, 120, 121, 130, 131, 140, & 141) located?

Located on each SG restricting orifice.

Where are the Main Steam Pressure instruments located (MPPs)?

On the main steam line from the SG before the PORV.

What inputs from the MSS are to the SI signal?

1. SG differential pressure of 100 psid between 2 SGs - 2 of 3 on any steam line.

2. SG pressure 500 psig and lowering on one SG - 1 of 1 on 2 SGs, manual block with P-12.