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Flashcards in Auxiliary Feedwater System Tech Specs Deck (16):
1

ORM 3.5 “Auxiliary Feedwater Alternate Suction”

During MODES 1, 2, and 3, and MODE 4 when steam generator is relied upon for heat removal.

  • One fire protection pump shall be functional.
  • The fire water makeup to the AFW pumps P-8A/P-8B suction and the service water to the AFW pump P-8C suction shall be operable.

2

ORM 3.17.6 “AFW Flow Indications”

ORM 3.17.6 “AFW Flow Indications”

One AFW Flow indicator for one or more flow paths inoperable:

  • Within 2 hours, Determine the OPERABILITY of the associated AFW flow control valve; the requirements of Technical Specification LCO 3.7.5 may apply

With two AFW flow indicators for one flow path inoperable:

  • Immediately, Declare the associated control valve shall immediately be declared inoperable and the requirements of TS LCO 3.7.5 apply.

3

What is the basis for ORM 3.17.6?

Each AFW feed line is provided with two separate flow indication channels. 

  • One channel provides an input to the associated AFW flow control valve as well as control room flow indication;
  • The other provides flow indication in the control room. 

A flow switch from each of the flow indicator channels provides a flow signal to the AFW pump sequencing circuitry. 

Flow indication channel failures which affect only indication, or which cause the valve to fail open do not necessarily cause the valve to be inoperable.

If two flow indication channels for one AFW feed line become inoperable there is no way to verify flow through that line; the associated AFW flow control valve must be declared inoperable

 

4

T.S. 3.3.3 Engineered Safety Features (ESF) instrumentation

T.S. 3.3.3 Engineered Safety Features (ESF) instrumentation.

During Modes 1, 2 and 3:

Four AFW bistables and associated instrument channels shall be OPERABLE

  • – One or more Functions with one ESF bistable or associated instrument channel inoperable
  • Place affected bistable in trip within 7 Days

Function 4 of Table 3.3.3-1 requires AFAS (A and B S/Gs) Engineered Safety features instrumentation to be operable with a trip setting ≥ 25.9% narrow range

Instrument channels include the level measurement loop and the Low Level AFAS bistable

5

T.S. 3.3.3 Engineered Safety Features (ESF) instrumentation Basis

T.S. 3.3.3 Engineered Safety Features (ESF) instrumentation Basis

The allowable level value assures that AFW flow would be initiated while the SG could still act as a heat sink and steam source, and to assure that a reactor trip would not occur on low level without the actuation of AFW.

6

T.S. 3.3.4 Engineered Safety Features Logic and Manual Initiation

T.S. 3.3.4 Engineered Safety Features Logic and Manual Initiation

During MODES 1, 2, and 3

Two ESF Manual and two ESF Actuation Logic channels and associated removal channels shall be OPERABLE

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One or more Functions with one Manual Initiation, Bypass Removal, or Actuation Logic channel inoperable. Restore channel to OPERABLE status within 48 hours

(1)    Manual Initiation – Each train of AFAS may be manually initiated with either of two sets of controls. Only one set of manual controls is required to be OPERABLE for each AFW train. One set of controls are the pushbuttons provided to actuate each train on the C-11 panel; the other set of controls are those manual controls provided on C-01 for each AFW pump and flow control valve.

(2)    Actuation Logic – Sensing and Actuation Cabinets (4 sensing channels, 2 actuation channels)

7

T.S. 3.3.4 Engineered Safety Features Logic and Manual Initiation Basis

T.S. 3.3.4 Engineered Safety Features Logic and Manual Initiation Basis

Actuate AFW to preclude the loss of the steam generators as a heat sink (in the event the normal feedwater system is not available)

8

T.S. 3.3.7 Post Accident Monitoring

T.S. 3.3.7 Post Accident Monitoring

During MODES 1, 2, and 3

Requires 2 Wide Range level instruments per S/G

  • Level span coverage from tube sheet (-140%) to the steam separators (+150%)

LCO 3.3.7.A – One or more Functions with one required channel inoperable

A.1 Restore required channel to OPERABLE status within 30 days

 

9

T.S. 3.3.7 Post Accident Monitoring Basis

T.S. 3.3.7 Post Accident Monitoring Basis

Indication is provided to monitor decay heat removal via the S/Gs.  Indication is used during a S/G tube rupture to determine which S/G has the ruptured tube.  It is also used to determine when to initiate once through cooling on low water level.

10

T.S. 3.3.8 Alternate Shutdown System

T.S. 3.3.8 Alternate Shutdown System

During MODES 1, 2, and 3

The Alternate Shutdown Functions for S/G water level and AFW indications shall be OPERABLE

  • 1 Wide Range level instrument per S/G
  • 1 AFW flow indication per S/G
  • Low suction pressure alarm (P-8B)
  • P-8B steam supply valve control
  • 1 AFW flow controller for each S/G

One or more required Functions inoperable. Restore required Function to OPERABLE status within 30 days

11

T.S. 3.3.8 Alternate Shutdown System Basis

T.S. 3.3.8 Alternate Shutdown System Basis

Provides operator with sufficient instrumentation and controls to maintain the plant in a safe shutdown condition from a location other than the control room.  

A safe shutdown condition is defined as MODE 3. Panel C-150 provides control of the AFW flow control valves, AFW turbine steam supply Valve and indication of AFW flow and Steam Generator water level.

Equipment controls that are required by the alternative dedicated method of maintaining MODE 3 are as follows:

  • AFW flow control valves (CV-0727 and CV-0749
  • Turbine-driven AFW pump

Instrumentation systems displayed on the Auxiliary Hot Shutdown Control Panel are:

  • AFW flow (HIC-0727 and HIC-0749C)
  • Turbine-driven AFW pump low-suction pressure warning light
  • SG level

12

T.S. 3.7.5 Auxiliary Feedwater

T.S. 3.7.5 Auxiliary Feedwater

During MODES 1, 2, and 3 and MODE 4 when S/G is relied upon for heat removal

Two AFW trains shall be OPERABLE

  • Only one AFW train, which includes a motor driven pump, is required to be OPERABLE in MODE 4
  • Steam driven pump is only required to be OPERABLE prior to making reactor critical
  • Two AFW pumps may be placed in manual for testing, for a period of up to 4 hours

 

13

T.S. 3.7.5 Auxiliary Feedwater Actions

 

T.S. 3.7.5 Auxiliary Feedwater Actions

One or more AFW trains inoperable in MODE 1,2, or 3. Restore Operable in 72 hours.

Required Action and associated Completion Time of Condition A not met OR Less than 100% of the required AFW flow available to either steam generator OR Less than two AFW pumps OPERABLE in MODE 1, 2, OR 3

B.1 Be in MODE 3 within 6 hours AND

B.2 Be in MODE 4 within 30 hour

14

T.S. 3.7.5 Auxiliary Feedwater 100% Flow

T.S. 3.7.5 Auxiliary Feedwater 100% Flow

LCO 3.0.3 and all other LCO Required Actions requiring MODE changes or power reductions are suspended until at least 100% of the required AFW flow is available.

Initiate action to restore one AFW train to OPERABLE status immediately

Each AFW pump is capable of providing 100% of the required capacity to the steam generators as assumed in the accident analysis.

15

T.S. 3.7.6 Condensate Storage and Supply

T.S. 3.7.6 Condensate Storage and Supply

During MODES 1, 2, and 3 and MODE 4 when S/G is relied upon for heat removal.

The combined useable storage volume of the Condensate Storage Tank (CST) and Primary Makeup Storage Tank (T-81) shall be ≥ 100,000 gallons.

SHO-1 limits

  • T-2 (CST) level (LIA-2021) ≥ 71%
  • T-81 (PMW) level (LIA-2020) ≥ 83%

Volume not within limit

  • Verify OPERABILITY of backup water supplies within 4 hours AND once per 12 hours thereafter AND
  • Restore condensate volume to within limit within 7 days

16

T.S. 3.7.6 Condensate Storage and Supply Basis

T.S. 3.7.6 Condensate Storage and Supply Basis

The CST and T-81 must contain sufficient cooling water to remove decay heat for 8 hours following a reactor trip from 2580.6 MWth.

This amount of time allows for cool down of the PCS to SDC entry conditions, assuming a coincident loss of offsite power and the most adverse single failure.

In doing this the CST and T-81 must retain sufficient water to ensure adequate net positive suction head for the AFW pumps, and makeup for steaming required to remove decay heat