ML14178B336

6/25/2014, Meeting Slide for Sequoyah Nuclear Plant, Units 1 and 2 Electrical Tech Specs

ML14178B336
Person / Time
Site:	Sequoyah
Issue date:	06/25/2014
From:	Tennessee Valley Authority
To:	Andrew Hon Plant Licensing Branch II
Hon A DORL/LPL2-2 301-415-8480
References
Download: ML14178B336 (12)

Text

Sequoyah Nuclear Plant Sequoyah Nuclear Plant Electrical Tech Specs June 25, 2014

Agenda g

• Sequoyah Electrical Distribution System SQN Electrical Lineups

• SQN Electrical Lineups

• CTS - ITS Comparison

• Discussion

• Discussion 2

Sequoyah Electrical Distribution System The Class 1E onsite electrical distribution system consists of two independent and redundant electrical subsystems with two di l

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h b

t E

h b

t i

diesel generator sets on each subsystem. Each subsystem is capable of supplying the necessary safety-related loads.

Two physically independent offsite circuits are met by a p y y

p y

combination of power sources (USSTs and CSSTs) whereby each load group is either powered from a separate offsite circuit, or an alternate power source is available to one of the offsite circuits circuits.

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Sequoyah Electrical Lineups Configuration #1 Two offsite circuits consisting of:

a. CSST A to 6.9 kV Shutdown Board 1B-B and 6.9 kV Shutdown Board 2B-B, and

b. CSST C to 6.9 kV Shutdown Board 2A-A and 6.9 kV Shutdown Board 1A-A.

4

Sequoyah Electrical Lineups 5

Sequoyah Electrical Lineups Configuration #2 Two offsite circuits consisting of:

a. Normal power source alignments p

g 1)

USST 1A to 6.9 kV Shutdown Board 1A-A, 2)

USST 1B to 6.9 kV Shutdown Board 1B-B,

)

3)

USST 2A to 6.9 kV Shutdown Board 2A-A, and 4)

USST 2B to 6.9 kV Shutdown Board 2B-B.

b. Alternate power source alignments 1)

CSST A to 6.9 kV Shutdown Board 1B-B, and 6

)

CSS to 6 9 S utdo oa d

, a d 2)

CSST A to 6.9 kV Shutdown Board 2B-B.

Sequoyah Electrical Lineups 7

CTS - ITS Comparison (Unit 1)

Inoperable power source CTS Action ITS Action DG 1A-A or DG 1B-B Restore DG in 7 days.

Restore DG in 7 days.

DG 1A-A and DG 2A-A Restore DGs in 7 days.

Restore DGs in 7 days.

OR DG 1B-B and DG 2B-B DG 1A-A and/or DG 2A-A AND DG 1B-B and/or DG 2B-B Restore one train of DGs in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Restore one train of DGs in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

DG 2A-A or DG 2B-B Restore DG in 7 days.

Declare associated required features inoperable in 7 days.

- For DG 2A-A: ABGTS Fan A-A and 125 V Vital Batt Chgr III 8

and 125 V Vital Batt Chgr III

- For DG 2B-B: ABGTS Fan B-B and 125 V Vital Batt Chgr iV

CTS - ITS Comparison (Unit 1) Continued Inoperable power source CTS Action ITS Action Offsite power to 1A-A or 1B-B Restore offsite circuit in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Restore offsite circuit in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Offsite power to 1A-A and 2A-A Restore offsite circuit in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Restore offsite circuit in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

OR Offsite power to 1B-B and 2B-B Offsite power to 1A-A and/or 2A-A AND Offsite power to 1B-B and/or 2B-B Restore one offsite circuit in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Restore one offsite circuit in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Offsite power 2A-A or 2B-B only Restore in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Declare associated required features inoperable in 7 days.

- For DG 2A-A: ABGTS Fan A-A and 125 V Vital Batt Chgr III 9

and 125 V Vital Batt Chgr III

- For DG 2B-B: ABGTS Fan B-B and 125 V Vital Batt Chgr iV

CTS - ITS Comparison (Unit 1) Continued Inoperable power source CTS Action ITS Action Offsite power to 1A-A, or 1A-A and 2A-A, or 1B-B, or 1B-B and 2B-B AND Restore offsite circuit or DG in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Restore offsite circuit or DG in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

DG 1A-A or 1B-B Offsite power to 2A-A or 2B-B AND Restore offsite circuit or DG in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Restore DG in 7 days.

AND AND DG 1A-A or 1B-B AND Declare associated required features inoperable in 7 days.

Offsite power to 1A-A, or 1A-A and 2A-A, or 1B-B, or 1B-B and 2B-B AND Restore offsite circuit or DG in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Restore offsite circuit in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

AND Declare associated required 10 DG 2A-A or 2B-B features inoperable in 7 days.

CTS - ITS Comparison (Unit 1) Continued Inoperable power source CTS Action ITS Action Offsite power to 2A-A or 2B-B AND DG 2A-A or 2B-B Restore offsite circuit or DG in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Restore offsite circuit or DG in 7 days.

AND I

di t l d l

i t d Immediately declare associated required features inoperable, if power sources are on the same 6.9 kV Shutdown Board.

Two offsite circuits AND One or more Train A or Train B DGs Enter LCO 3.0.3 Enter LCO 3.0.3 DGs One offsite circuit AND Enter LCO 3.0.3 Enter LCO 3.0.3 11 One or more Train A AND Train B DGs

Discussion Questions?

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