Text

Proposed Tech Specs Re Diesel Generator Battery Float Voltage,Isolation Times for Containment Isolation Valves, Instrumentation Surveillance Requirement Test & Reflection of Installation of Permanent Hydrogen Mitigation Sys
	ML20069D819
Person / Time
Site:	Sequoyah
Issue date:	09/17/1982
From:	; TENNESSEE VALLEY AUTHORITY
To:	;
Shared Package
ML20069D807	List: ML20069D803; ML20069D819;
References
	TVA-SQN-TS-36, NUDOCS 8209220281
	Download: ML20069D819 (79)
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ENCLOSURE 1 l

i SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATIONS TVA-SQN-TS-36 CHANGE NO. 1 DIESEL GENERATOR BATTERY FLOAT VOLTAGE i

i 8209220281 820917 PDR ADOCK 05000327 PDR P

o ,

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) 4.8.1.1.3 The 125-volt D.C. distribution panel,125-volt D.C. battery bank and associated charger for each diesel generator shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying:

1. That the parameters in Table 4.8-la meet the Category A limits.

2. That the total battery terminal voltage is greater than or equal to 124-volts on float charge.

b. At least once per 92 days by:

1. Verifying that the parameters in Table 4.8-la meet the

- Category B limits,

2. Verifying there is no visible corrosion at either terminals or connectors, or the cell to terminal connection resistance of these items is less than 150 x 10 e ohms, and

3. -Verifying that the average electrolyte temperature of 6 connected cells.is above 60 F.

c. At least once per 18 months by verifying that:

1. The cells, cell plates and battery racks show no visual indication of physical damage or abnormal deterioration.

2. The battery to battery and terminal connections are clean, tight and coated with anti-corrosion material.

3. The resistance of each cell to terminal connection is less than or equal to 150 x 10 8 ohms.

4.8.1.1.4 Reports - All diesel generator failures, valid or non-valid, shall Reports of be reported to the Commission pursuar.t to Specification 6.9.1.

diesel generator failures shall include the information recommended in Regula- If tory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977.

the number of failures in the last 100 valid tests (on a per nuclear unit basis) is greater than or equal to 7, the report shall be supplemented to include the additional information recommended in Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977.

SEQUOYAH - UNIT 1 3/4 8-6

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ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

f. At least once per 10 years" by:

1. Draining each fuel cil storage tank, removing the accumulated sediment anc. cleaning the tank using a sodium hypoclorite solution, and .

2. Performing a pressure test of those portions of the diesel fuel oil system designed to Section III, subsection ND of the ASME Code at a test pressure equal to 110 percent of the system design pressure. ,

4.8.1.1.3 The 125-volt D.C. distribution panel, 125-volt 0.C. battery bank and associated charger for each diesel generator shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying:

1. That the parameters in Table 4.8-la meet the Category A limits.

2. That the total battery terminal voltage is greater than or

-- _ equal to'12'4-volts on float charge. ,

b. At least once per 92 days by:

1. Verifying that the parameters in Table 4.8-la meet the Category B limits,

2. Verifying there is no visible corrosion at either terminals or connectors, or the cell to terminal connection resistance of these items is less than 150 x 10 8 ohms, and

3. Verifying that the average electrolyte temperature of 6 connected cells is above 60 F.

c. At least once per 18 months by verifying that:

1. The cells, cell plates and battery racks show no visual indication of physical damage or abnormal deterioration.

2. The' battery to battery and terminal connections are clean, tight and coated with anti-corrosion material.

3. The resistance of each cell to terminal connection is less -

than or equal to 150 x 10 s ohms.

"These requirements are waived for the initial surveillance.

'SEQUOYAH - UNIT 2 3/4 8-6 li ..m

TVA-SQN-TS-36 Change No. 1 Sequoyah Nuclear Plant Justification for Proposed Technical Specification Change DIESEL GENERATOR BATTERY FLOAT VOLTAGE The diesel generator batteries at Sequoyah have been replaced with lead calcium cells. The manufacturer (C&D Batteries) recommends a minimum float voltage of 2.17 volts for each cell. The Sequoyah batteries consist of 19 three cell units. The minimum total float voltage requirement is:

2.17 volts / cell x 57 cells = 123.69 volts The minimum float voltage specified in surveillance requirement 4.8.1.1.3.a.2 should be 124 volts (rounded up).

The present technical specification test value of 129 volta exceeds the manufacturer's maximum of 128.25 volts. The larger voltage can shorten battery life.

A copy of the manufacturer's specification sheets and part of the instruction manual are included are attachments.

Supersedes Section 12-337 25 to 200 Amp. Hours DCU - Lead Calcium 9 STATIONARY BATTERIES s DU - Lead Antimony SPECIFICATIONS -

CELLS PER UNIT ....... One, two or three ,. h PLATES Height Width Thickness Positive ........... 5.88" 5.63" 0.266" _ ,

Neg steve 5.88" 5.63" 0.170" I' .

.... .. . 7 5.88" 6.63" 0.110" I Outside Negative ...... ,

[ l P ,'

e SPECIFIC GRAVITY ..... 1.210 nominal at 77 F CO NT AI N E R . . . . . . . . . Ti.,osprent thermoplastic p CELL COVER ..... ... Thermoplastic 6 t j I .

SE P AR ATORS . . . . . . . . . Microporous , . g RETAINERS ........ Fibrous glass met -

ELECTROLYTE HEIGHT g '

l g ABOVE PLATES . .... 1.75" t scept 11 plate - l, 1.63" N '

SEDIMENT SPACE , ... 0.5" except 11 plate - .= , ;

O.56" , h !!

TE HMIN ALS .. .. . DCU/DU 3 thru 11. Two flag terminals with 1/4" - 20 bolts DCU/DU - 13 thru 17: Two 0.75"

, posts with 5/16"- 18 stud and cap nuts 30CU-7

I VENT CAPS ...... ... Flame arrestor type L1J # -

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Nommel Cap 1.75 VPC U 7 7'F AP8 " -

{* . EbO Dwarelt Demonssons Weeght E let t-

.I~ of CeH h lindudes Connector Volteve Deopt

f. , e . c. < ' UbsJ per Cell

,6 per Ampere Hours Amperes

, l-b "- libsj ad 30 15 L (sn.) W (en) H (an.)

Calciu m Antimony 8 Hrs. 6 Hrs. 3 Hrs. 1.6 Hrs. 1 Hr. Men. Men. 1 Men. Filled Pock ed

^ 3.59 18 22 3 2DCU-3 20U 3 2 25 22 19 15.3 ' 12.5 19 24.9 37.5 12.5 24.9 37.5 5.28 27 32 3 g 3DCU 3 30U 3 3 25 22

19 15.3 19 3.59 22 26 2E

! ~ ." / i' 2DCU.S 20U-5 2 50 44 38 30.6 25 38 492 75 L' '

lM 5.28 33 38 2.8

g 3DCU-5 30U 5 3 50 44 38 30.6 25 38 492 75

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74.7 6.38 7.38 10.31 36 40 Sa 2DCU 7 20U 7 2 75 66 57 45.9 38 57 111

{ f ,,

~' ' "" 9.47 53 58 5.8

' 3DCU 7 3DU 7 3 75 06 57 45.9 38 57 74.7 111 76 99.6 148 6.38 40 44 5.3 y , 20CU 9 2DU-9 2 100 88 76 61.2 50

7h 9.47 60 65 5.3

, ~ " L* . s 3DCU-9 300 9 3 100 88 76 61.2 50 76 99.6 148 7.50 48 55 52 LL h 1 i, L 2DCU 11 20U 11 2 120 105 90 75 60 96 126 184 '

7.19 10.25 2 y if 9

_ ' ' f ,., 1 JDCU 11 3DU11 3 120 105 90 75 60 96 126 184 I'*13 71 79 5A

- i y r.

6.38 12.5 LO oauc

[ DCU 13 0013 1 .150 132 114 91.8 75 114 143.4 220 3H 44 DCU-15 DU-15 175 154 132 88 133 174.3 253 E38 7.38 10.75 40 as t i .5 1 107.1 6.38 42 48 10.5 v DCU '? DU-17 1 200 176 150 122.4 100 152 199.2 288 Note: Electrolyte weighs appromerr.ately 10 lbs. per gaHon (1.?I t ;

Data based on discharge from float at 77 F c h ) for a rmnimum of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months m accordance with Federal Specification W 8134

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44 "Ta-e 4 e in i. ao a re ao AMPERES PsR POssTlvt PLATE Data thsted on discharge frorn float at 77 F for a nunirnurn of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months en accordance with Federal Specification W B 134.

RACK SPECIFICATIONS a a h -

b p.. ..-- i.. . . ,

Two Tir n uooes nD rol 10 I:

hl i Two sTI P u des nD 703. t o 4l 4

THut E Titn u.a.: nD . For .10 h

W.e h 13 . [_) w.dih. 17 5.n. It" '$ w.ath is in. [f 9' t

Height 31.38 6n. %w He@t: 24.M en. 1._ e <_ 1 Height: $6.M 6se, l e-e-et No.

es te. sh it t we.shi No. t each ets we+t Ne teach lt ) we she No.

Reg'd. ft . Reg'd. In the. Rega'd.

Esotery Colle it. The Nue .

12 3 46 1 3 47 8 - -

2DCU!DU 3 47 - -

m, , 23/24 3 46 1 3 1 -

26 3 46 1 3 47 1 -

3DCU/DU S 60 5 61 1 6 62 1 6 102 1 12 3 46 1 3 47 1 - -

2DCU.DU j 3 79 1 23/24 4 64 1 4 SS 1

'"'" 4 55 1 3 19 f 26 4 54 1 30CU/Du 9 60 9 106 1 9 108 1 4 91 1 3 47 I - -

20CUIDU 11 12 3 46 1 4 55 1 3 79 {

23/24 4 64 1 91 1 end 6 62 1 4 26 5 61 1 3DCU 'DU 11 114 10 116 1 iO 201 1 60 10 1 3

4 S4 1 DCU/DU 13 y2 4, , 5 6

102 184 1

1

7ti 8 IHL 1 8 100 1 4

- 1 DCU Du ll 60 9 1 01) 2 9 108 2 Nmes 1. Atmove date te for C& D stenderd rects ontv< For se6eerec zones. CAD type E P recis are eveitebee. See Section 12 660.

2. H.nh lengths for pqhee then th) seli t.atteteel Can be calculated by the for naile Nornier et cellt 6.* l'** o' uep u h

0.6) - 0.6

Total Rock t ength twheee L"is seageh of ceilJ W. e a. ... .. .e .. .t.co.. . . w.m .D e,nes,,, .

3. Itat ..se Joes not smiu.te thschness of o 4stersong, lacrosse nedth t y 0.5 4e umstwas seig when

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BATTERIES : ATTERIES Of: CANADA 3043 WALTON ROAD, PLYMOUTH Ms

TING PA 19462 150 CONN 6L CRESCE NT. UNIi 15. CONCORD. ONT AMIO L4K 186 T

an . hllM l company an l#.lIM corripany Printed in U.S.A. 10M/180

.a.

. _ _ _ _ _ - - . . . _ , , , . . .. . m v- . . sv;;.;.~.,taLr e:

If lead-celcium tha f:llowing cpplirs:

3.11 SUITABLE WATER FOR FILLING If in doubt about the suitabihty of the local water TABLE 11 LEAD CALCIUM CELLS supply for use in lead-acid batteries, consult your near- '

est C 1 D Representative. If he does not have a recent analysis report available, send a one-quart sample in a SP,GR. FLOAT VPC INITIAL /EQUAtlZE (VPC)

L chemically clean non-metallic container and stopper. OF CELLS MIN. NOMINAL NOM. VPC prepaid to Technical Services Dept.,C & D Batter es Di. CELL VOLT.

vision, Eltra Corporation, 3043 Walton Road, Plymouth -e 1.210 2.17 2.20-2.25 2.13 2.33-2.38 Mcetmg, PA 19462. The sarnple will be analyzec' and a 1.225 2.18 2.22 2.27 2.15 2.36-2.d 0 report as to its safety for use in lead-acid battenes will 1.250 2.20 2.25 2,30 2.18 2.38 2.43 be forwarded. Indicate the source of the water and the 1.275 2 23 2.29-2.34 2.20 2.40-2.46 sender's name and location on the sample. 1.300 2.27 2.33-2.38 2.23 2.45-2.50 The quantity of water consumed by a battery is pro-portional to the amount of charge is receives. Lead-anti-mony batteries begin their life with low water consump. TABLE 111 - BRUSHING & TOR QUE SPECIFICATIONS tion, which increases as much as five or more times to. FOR CELL CONNECTIONS ward the end of their hfe. Lead-calcium batteries, be- CELT. RECOM. TYPE cause of the greater purity of their components, require TYPE TORQUE BRUSH only about one-tenth the water needed by equivalent-sized new lead-antimony batteries. This low requirement Communications remains constant during their entire life. Fig.10 gives Batteries the approximate water consumption for various size KT, KCT, LT, LCT 110 inch-Ibs. mre cells at the normal operating temperature of 77'F. UPS & Switchefiar O inch-lbs. brush 3.12 CONNECTING BATTERY TO CHARGER O(([ DCU 13,15.17 Only direct current (dc) is used for charging. With K A & KC S. 7,11,13 the charging source de-energized, connect the positive KY & KCY 7 terminal of the battery to the positive of the charger or KCX 1,9,11,13,15,17 system and the negative terminal of the battery to the L A & LC .13,15,17 LY & LCY - 5, 7 negative of the charger or system. Re-energize the sys-tem following procedures that are provided in charger Photovoltaic Battenes DCPSA 11,13,15,17 A manual. DCPSD - 9,11,13 g K CPSA 5, 7, 9,11,13, 4.0 INITIAL CHARGE 15.17 All batteries shipped wet and fully charged lose KCPSD . 5, 7,9,11.,13 some charge in transit or while standing idle before in- LCPSA 5, 7,11,13,15, stallation. At the first opportunity, they should be given 17,19,21,23,25 their first or initial charge using the following method. LCPSD - 5,11,13,15. ,

17,19 4.1 CONSTANT VOLTAGE METHOD Mini-Tank Cells MT & MCT 160 inch ibs. wire This method of giving the initial charge is the most brush common and is used when circuit voltage limitations ~

make it impractical to use the constant current method. Cells mth posts that'have copper inserts:

First, determine the maximum allowable voltage that may be applied to the connected equipment. Divide this Tank Ms voltage by the number of cells in the battery thus ob- UPS & Switchg ar Batteries 160 inch-lbs. plastic taining the maximum voltage per cell. Determine if the K A & KC-15,17,19,21 -O inch-Itss. tristle battery is a lead-antimony or lead-calcium type by the KY & KCY 23,25 + 5 inch-lbs. brush nomenclature on the cell. If lead-antimony, refer to the KCX 19,21,23,25,27, following table and charge for the time indicated at the 29,31,33 maximum voltage permitted by the associated equip- LA & LC 19,21,23,25, ment. 27,29,31,33 LC TABLE I- LEAD-ANTIMONY CELLS LY & LC 9,11,35,37 39 CHARGE VOLTAGE PER CELL (VPC) " * ' ' " " " " * "' i"#

(1.210 SPECIFIC GRAVITV) DW 3, 5, 7, 9, 70 inch m$

~ ~lNITIAL FL' OAT EdUALIZE 11 -O inch ibs. la ush VPC HOURS VPC VPC DCPSA - 3, 5, 7, a +5 inch-lbs.

2.39 40 2.15 to 2.17 2.33 OCPSD . 3, 5, 7 2.36 60 for 8 to 24 hrs. Cells with small flag terminals (no insertsh 2.33 110 A. AC, 8. BC and irnali 15 inch 'bs. wire 2.30 168 specialty batteries 3 inch-lbs. brush 2.24 210 + 0 inch lbs.

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e ENCLOSURE 2 SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATIONS TVA-SQN-TS-36 CHANGE NO. 2 L ISOLATION TIMES FOR CONTAINMENT ISOLATION VALVES 4

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INSTRUMENTATION TABLE 3.3-5 (Continued)

TABLE NOTATION (1) Diesel ganerator starting and sequence loading delays included. Response time lir it includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps, SI and RHR pumps.

(2) Using air operated valve (3) The.following valves are exceptions to the response times shown in the table and will have the values listed in seconds for the initiating signals and function indicated

Valves: FCV-26-240, -243 Response times: 2.d. 21(8)f 31(9) 3.d. 22(8) 4.d. 21(8)/ 31(9) 5.d. 24(8)/ 34(9) 6.d. 21(8)f 31(9)

Valves: FCV-61-96, -97, -110, -122, -191, -192, -193, -194 Response times:

2.*d . 31(8) 3.d. 32(8) 4.d. 31(8) 5.d. 34(8) 6.d. 31(8)

Valve; FCV-70-143 Response times: 2.d. 61(8)/ 71I9) 3.d. 62(8) 4.d.

5.d. 61(0)/

64(8) 71(9) 7l m 6.d. 61(8)jj 74 (4) On 2/3 any Steam Generator (5) On 2/3 in 2/4 Steam Generator l

l (6) Radiation detectors for Containment Ventilation Isolation may be excluded from Response Time Testing.

(7) Diesel generator starting and sequence loading delays ng included.

Offsite power available. Response time limit includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps.

(8) Diesel generator starting and sequence loading delays not included.

Response time limit includes operating time of valves.

(9) Diesel generator starting and sequence loading delays included. Response time limit includes operating time of valves.

SEQUOYAH UNIT 1 3/4 3-33

INSTRUMENTATION TABLE 3.3-5 (Continued)

TABLE NOTATION (1) Diesel generator starting and sequence loading delays included. Response time limit includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps, SI and RHR pumps.

(2) Using air operated valve (3) The following valves are exceptions to the response times shown in the table and will have the values listed in seconds for the initiating signals and function indicated:

Valves: FCV-26-240, -243 Response times: 2.d. 21(8)/ 31(9) 3.d.

4.d. 22((8) 21 8)/ 3159) 5.d. 24(8)/ 34(9) 6.d. 21(8)/ 31(9)

Valves: FCV-61-96, -97, -110, -122, -191, -192, -193, -194 Response times:

2 .'d . 31(8) 3.d. 32(8) 4.d. 31(8) 5.d. 34(8) 6.d. 31(8)

Valve: FCV-70-143 Response times: 2.d. 61(8)/ 71(9) 3.d. 62(8) 4.d. 61(8)j 71W 5.d. 64(8)/ 74C9) 6.d. 61 I0)/ 71 (4) On 2/3 any Steam Generator (5) On 2/3 in 2/4 Steam Generator (6) Radiation detectors for Containment Ventilation Isolation may be excluded from Response Time Testing.

(7) Diesel generator starting and sequence loading delays ng included.

Offsite power available. Response time limit includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps.

(8) Diesel generator starting and sequence loading delays not included.

Response time limit includes operating time of valves.

(9) Diesel generator starting and sequence loading delays included. Response time limit includes operating time of valves.

SEQUOYAll UNIT 2 3/4 3-33

TVA-3QN-TS-36 Change No. 2 Sequoyah Nuclear Plant Justification for Proposed Technical Specifications ISOLATION TIMES FOR (X)NTAINMENT ISOLATION VALVES The isolation times for the containment isolation valves on the ice condenser glycol lines were increased from 10 seconds to 30 seconds. These changes were approved by the NRC on May 4,1982 for units 1 and 2

( Amendment 13 for the unit 1 operating license; Amendment 4 to the unit 2 operating license). During the process of revising our procedures, an error of omission was discovered in our original change request. Although the valve stroke time was changed, the overall phase A response time, which includes the valve stroke time, was overlooked. Also, a similar error was discovered in the fire protection system containment isolation valves.

The fire protection valves list a 20-second valve stroke time. However, the phase A response time is not consistent with the valve stroke time.

NRC has myiewed and approved the response times for both sets of valves.

This change only corrects errors in the implementation of the response time.

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I ENCLOSURE 3 SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATIONS TVA-SQN-TS-36 CHANGE NO. 3 INSTRUMEEATION SURVEILLANCE REQUIREMENT TEST FREQUENCY OF TABLES 4.3-1 AND 4 3-2

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TABLE 4.3-1

,EN REACTOR TRIP SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS I5!:

E -

MODES IN WHICH i

CHANNEL CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE l c .

TEST REQUIRED 1 5 FUNCTIONAL UNIT CHECK CALIBRATION i

, 1. Manual Reactor Trip N.A. N.A. S/U(1) 1, 2, and * ,

2. Power Range, Neutron Flux 5 0(2),M(3) q 1, 2

(' ' -

and Q(6)

Power Range, Neutron Flux, N.A. R(6) 1, 2

3. Q High Positive Rate .

4. Power Range, Neutron Flux, N.A.

R(6) Q 1, 2 High Negative Rate

$ 5. Intermediate Range, S R(6) S/U(l) 1, 2, and

y Neutron Flux

6. Source Range, Neutron Flux S(7) R(6) Q and S/U(1) 2, 3, 4, 5, and *

7. Overtemperature Delta T S R H 1, 2

8. Overpower Delta T S R M 1, 2

9. Pressurizer Pressure--Low S R Q 1, 2

10. Pressurizer Pressure--High S R Q 1, 2

11. Pressurizer Water Level--High S R Q 1, 2

12. Loss of Flow - Single Loop S R 1

13. Loss of Flow - Two Loops S R N.A. I

l l -

TABLE 4.3-1 (Continued) f

+

@ REACTOR TRIP SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS

. S!

2-

CHANNEL MODES IN WHICH

' ' CHANNEL ~ FUNCTIONAL SURVEILLANCE CHANNEL CHECK CALIBRATION TEST REQUIRED E FUNCTIONAL UNIT 1, 2

. 14. Main Steam Generator Water S R q

Level--Low-Low R 1, 2 ,

15. Steam /Feedwater Flow Mismatch and S Q Low Steam Generator Water Level N.A. M l

16. Undervoltage - Reactor Coolant R .

Pumps '

M 1

17. Underfrequency - Reactor Coolant N.A. R Pumps .

18. Turbine Trip A. Low Fluid Oil Pressure N.A. N.A. S/U(1) 1 w

Turbine Stop Valve Closure N.A. M.A. S/U(1) , 1 1 B.

1, 2

19. Safety Injection Input from ESF N.A. N.A. M(4)

Y N.A. N.A. M(5) and S/U(1) 1, 2, and *

20. Reactor Trip Breaker N.A. M(5) 1, 2, and *

21. Automatic Trip Logic N.A.

22. Reactor Trip System Interlocks 2, and

A. Intermediate Range N.A. R S/U(8)

Neutron Flux, P-6 B. Power Range Neutron N.A. R S/U(8) 1 Flux, P-7 N.A. R S/U(8) 1 y f C. Power Range Neutron Flux, P-8

@m Power Range Neutron N.A. R S/U(8) 1, 2

@g D.

Flux, P-10 "g

E. Turbine Impulse Chamber N.A. R S/U(8) 1

.o Pressure, P-13 I g

($ F. Power Range Neutron N.A. R S/U(8) w Flux, P-9 1, 2, and

G. Reactor Trip, P-4 N.A. R S/U(8)

_. _ = .. __ _ _--_.

TABLE 4.3-2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS E3 E

CHANNEL MODES IN WHICH

j. .

CHANNEL FUNCTIONAL - SURVEILLANCE sc CHANNEL CHECK CALIBRATION TEST REQUIRED

! El FUNCTIONAL UNIT e

1. SAFETY INJECTION AND FEE 0 WATER ISOLATION N.A. M(1) 1, 2, 3, 4

a. Manual Initiation N.A. .

Automatic Actuation Logic N.A. N.A. M(2) 1, 2, 3, 4 b.

Containment Pressure-High S R q 1,2,3 c.

y$ d. Pressurizer Pressure--Low S R q{ 1, 2, 3 j'

e. Differential Pressure S R ql 1, 2, 3 4- Between Steam Lines--High R 1, 2, 3

f. Steam Flow in Two Steam S Lines--High Coincident with T --Low-Low or Steam Line 3yg \

Pressure--Low ,

2. CONTAINHENT SPRAY 4

N.A. M(1) 1, 2, 3, 4 .

a. Manual Initiation N.A.

s Automatic Actuation Logic N.A. N.A. 'M(2) 1, 2, 3, 4 ,

b.

Containment Pressure--High-High 5 R Q 1, 2, 3 c.

i TABLE 4.3-2 (Continued) m IE ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS h$

1 e

, c: CHANNEL MODES IN WHICH 35 CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE CALIBRATION TEST REQUIRED

([ FUNCTIONAL UNIT CHECK _

3. CONTAINMENT ISOLATION

a. Phase "A" Iso,1ation N.A. N.A. M(1) 1, 2, 3, 4

1) Manual 4 2) From Safety Injection N.A. N.A. M(2) 1, 2, 3, 4 Automatic Actuation Logic

b. Phase "B" Isolation 2: N.A. N.A. M(1) 1, 2; 3, 4

1) Manual w

N.A. N.A. M(2) 1, 2, 3, 4 h 2) Automatic Actuation Logic q 1, 2, 3

3) Containment Pressure-- R S

High-High

. c. Containment Ventilation Isolation

1) Manual N.A. N.A. M(1) 1, 2, 3, 4

2) Automatic Isolation Logic N.A. N.A. M(2) 1, 2, 3, 4 fi R M 1, 2, 3, 4

3) Containment Gas Monitor S Radioactivity-High l

e

TABLE 4.3-2 (Continued)

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION g SURVEILLANCE REQUIREMENTS z

e c- '

CHANNEL MODES IN WHICH

- 3 CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE

[ FUNCTIONAL UNIT CHECK CALIBRATION TEST REQUIRED

4) Containment Purge Air S R M 1, 2, 3, 4 Exhaust Monitor Radio-activity-High e

~

5) Containment Particulate 5 --

R M 1, 2, 3, 4 .

Activity-High -

4. STEAM LINE ISOLATION

W ,

3 a. Manual N. A. N.A. M(1) 1, 2, 3

~

< h. Automatic Actuation logic N.A. N.A. M(2) 1, f, 3

.. Containment Pressure-- S R !'Q 1, 2, 3 n

' Sigh-High '

3 1m flow in Two Steam 5 R Q 1, 2, 3 C ces--High Coincident with ,

i, g-- Low-l.ow or Steam Line Pressure--Lcw '

5. TURBINE TRIP AND FEEDWATfR ISOLATION

a. Steam Generator Water S R ,Q 1,2,3 Level--High*High ,

}

6. AUXILIARY FEEDWATER i

a. Manual N.A. N.A. M(1) 1, 2, 3

b. Automatic Actuation Logic N.A. N.A. M(2) 1, 2, 3 l -

{ ,

TABLE 4.3-2 (Continued) .

Kt i E ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION E -

SURVEILLANCE REQUIREMENTS E .

' CHANNEL H0 DES IN WHICH CHANNEL FUNCTIONAL SURVEILLANCE E CHANNEL Z FUNCTIONAL UNIT CHECX CALIBRATION TEST . REQUIRED ,

, c. Main Steam Generator Water 5 '

R q 1, 2, .3 Level-Low-Low

d. S. I. See 1 above (all SI surveillance requirements)

e. Station Blackout N.A. R N.A. 1, 2, 3

f. Trip of Hain Feedwater H.A. N.A. R ,

1, 2 Pumps .

i g. Auxiliary Feedwater Suction N.A. R . H 1, 2, 3 .

Pressure - Low

1. LOSS OF POWER ,

R.

z w a. 6.9 kv 5:utdown Board a

w Undervoltage

1. Loss of Voltage S R H 1, 2, 3, 4

2. Load Shedding,,, S , R N.A. ,

1, 2, 3, 4 i

8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCKS N.A.

a. Pressurizer Pressure, N.A. R (4) 1, 2, 3 P-11 .

b. N.A. R (4) N.A. 1, 2, 3 T,yg, P-12

c. Steam Generator H.A. R (4) H.A. 1, 2 -

Level, P-14

f T

i .

TABLE 4.3-1 ~

ui REACTOR TRIP SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS E

.g MODES FOR WHICH CHANNEL h CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE IS CHECK CALIBRATION TEST REQUIRED c FUNCTIONAL UNIT z

N.A. N.A. S/U(1) 1, 2, and

U 1. Manual Reactor Trip 1, 2 ro

2. Power Range, Neutron Flux S D(2),M(3) Q ,

and Q(6) 1, 2 ,'

3. Power Range, Neutron Flux, N.A. R(6) Q High Positive Rate

4. Power Range, Neutron Flux, N.A. R(6) Q! 1, 2 High Negative Rate S/U(1) 1, 2, and

y 5. Intermediate Range, S R(6) ,

Neutron Flux M 2, 3, 4, U Source Range, Neutron Flux S(7) R(6) M and S/U(1)

6. 5, and

R M 1, 2

7. Overtemperature AT S S R H 1, 2

8. Overpower AT R Q 1, 2

9. Pressurizer Pressure--Low S R- Q 1, 2

10. Pressurizer Pressure--High 5 ,

Q l., 2

11. P essurizer Water Level--High S- R .

R' Q l

12. Loss of Flow - Single Loop S Loss of Flow - Two Loops S R ,' N.A. 1 13.

R Q 1, 2 Steam Generator Water Level-- S 14.

Low-Low ,

TABLE 4.3-1 (Continued) j REACTOR TRIP SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS 8

s

CHANNEL MODES FOR WHICH

' CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE IS FUNCTIONAL UNIT CHECK CALIBRATION TEST REQUIRED E

'Q 15. Steam /Feedwater Flow Mismatch and S R Q 1, 2

. m Low Steam Generator Water Level

16. Undervoltage - Reactor Coolant N.A. R H 1 Pumps

17. Underfrequency - Reactor Coolant N.A. R M 1 .

Pumps

18. Turbine Trip '

A. Low Fluid Oil Pressure N.A. N.A. S/U(1) 1 B. Turbine Stop Valve Closure N.A. N.A. S/U(1)

I w

m

19. Safety Injection Input from ESF N.A. N.A. M(4) 1, 2

20. Reactor Trip Breaker N.A. N.A. M(5) and S/U(1) 1, 2, and *

21. Automatic Trip Logic N.A. N.A. M(5) 1, 2, and *

22. Reactor Trip System. Interlocks A. Intermediate Range N.A R S/U (8) 2, and

Neutron Flux, P-6 B. Power Range Neutron N. A. R S/U (8) 1 ,

Flux, P-7 C. Power Range _ Neutron N.A. R S/U (8) 1 Flux, P-8 ,

D. Power Range Neutron N.A. R S/U (8) 1, 2 Flux, P-10 E. Turbine Impulse Chamber N.A. R S/U (8) 1 Pressure, P-13 F. Power Range Neutron /

Flux, P-9 N.A.

G. Reactor Trip, P-4 R S/U (8) 1 N.A. R S/U (8) 1, 2, and

TABLE 4.3-2 IS ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRllMENTATION SilRVElll AliCL REQtilRfH[NIS

(!

x e

CHANNEL MODES FOR WHICll' c: SURVEILLANCE IS CilANNEL ' CllANNEL FUNCil0NAL 35 REQUIRED CllECK cal lBRATION TESI

~j FUNCTIONAL UNIT

1. SAFETY INJECIION AND FEEDWATER ISOLATION N.A. M(1) 1, 2, 3, 4

a. Manual Initiation N.A.

N.A. M(2) 1, 2, 3, 4

b. Automatic Actuation Logic N.A.

i 1, 2, 3

c. Containment Pressure-liigh S R q ,

Pressurizer Pressure--Low 5 R q 1, 2 , 3

d. .

II e. Differential Pressure S R q' 1, 2, 3 Between Steam Lines--liigh R q 1, 2, 3

f. Steam Flow in Two Steam 5 Lines--liigh Coincident with T,yg--Low-Low or Steam Line Pressure--Low

2. CONTAINMENI SPRAY N.A. M(1) 1, 2, 3, 4

a. Manual Initiation N.A.

N.A. M(2) 1, 2, 3, 4

b. Automatic Actuation Logic -N.A.

q 1, 2, 3

c. Containnient Pressure--liigh-fli0h S R w

9 TABLE 4.3-2 (Continued) m h ENGINEERED SAFETY FIA1URE AC10ATION SYSTEM INSTRUMENTATION SURVEILiANCE REQUIREMENIS Q

E CHANNEL M01)ES FOR WilICil CllANNEL CilANNEL FUNCIIONAL SURVL111ANCE 15 e CALIBRA110N 1EST REQUIRED CilECK 3

-4 FUNCTIONAL UNIT N 3. CONTAINMENT ISOLATION

a. Phase "A" Isolation N.A. N.A. M(1) 1, 2, 3, 4

1) Hanual N.A. M(2) 1, 2, 3, 4

2) From Safety Injection N.A.

Automatic Actuation Logic

b. Phase "B" Isolation N.A. N.A. M(1) 1, 2, 3, 4 y 1) Manual

2) Automatic Actuation Logic N.A. N.A. M(2) , 1, 2', 3, 4

" R 1, 2, 3 ,

3) Containment Pressure-- S Q 8 liigh-liigh ;

c. Containneent Ventilation Isolation N.A. N.A. M(1) 1, 2, 3, 4

1) Manual

2) Automatic Isolation Logic N.A. N.A. M(2) 1, 2, 3, 4 R M 1, 2, 3, 4

3) Containment Cas Monitor S Radioactivity-liigh

TABLE 4.3-2 (Continueil)

IE ENGINEERED SAFETY FEATURE ACTUATION SYSlfM INSTRilMENTATION l SURVEllLANCE REqulREMENT_S '

h x CHANNEL MODES FOR WillCil t *

' CilANNEL FUNCIl0NAL SURVEILIANCE IS c:

CilANNEL CAllt! RATION IfSI REQlllRED ClllCK

!) FUNCTIONAL UNIT M 1, 2, 3, 4

" 4) Containment Purge Air 5 R Exhaust Monitor Radio- l activi ty-liigh R H 1,2,3,4 5

l

5) Containment Particulate Ac tiv ity-liigh

4. STEAM LINE ISOLATION M(1) I , 2, 3 N.A. N.A.

a. Manual

}{

l_

N.A. M(2) ,1, 2, 3

b. .'utomatic Actuation Logic N.A.

R Q 1, 2, 3 Contas:' ment Pressure-- S c.

liigh-liigh

.R 1, 2, 3 Steam flow in Two Steam 5 Q d.

Lines--Iligh Coincident with I -- low-Low or Steam Line )

PfENsure--Low

5. TURBINE TRIP AND FEEDWAIER IS0lATION R 1, 2, 3

a. Steam Gener ator Water S Q I Level--liigh-liigh

6. AUXILI ARY IEEDWATER N.A. M(1) 1, 2, 3

a. Manual N.A.

N.A. H(2) 1, 2, 3

b. Automatic Actuation Lo0ic N.A.

N j TABLE 4.3-2 (Continued) ,

h ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION i SURVEILLANCE REQUIREMENTS 1 ,

E CHANNEL MODES FOR WHICH

" CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE IS FUNCTIONAL UNIT CHECK CAL 10 RATION TEST REQUIRED

c. Main Steam Generator Water S R q 1,2,3 Level-Low-Low

d. S.I. See 1 above (all SI surveillance requirements)

e. Station Blackout N.A. R N.A. 1, 2, 3

f. Trip of Main Feedwater N.A. N.A. R 1, 2 Pumps R

g. Auxiliary Feedwater Suction N.A. R M l', 2, 3 Y Pressure-Low ti

7. LOSS OF POWER

a. 6.9 kv Shutdown Board Undervoltage

1. Loss of Voltage S R M 1,2,3,4

2. Load Shedding S R N.A. 1, 2, 3, 4

8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCKS

a. Pressurizer Pressure, N.A. R(4) N.A. 1,2,3 P-11

b. T,yg, P-12 N.A. R (4) N.A. 1, 2, 3

c. Steam Generator N.A. R (4) N.A. 1, 2 Level, P-14

An instruction can be adequately reviewed in approximately 10 minutes.

This is an accumulated time of .667 hours0.00772 days 0.185 hours 0.0011 weeks 2.537935e-4 months per instruction or 392 manhours or 49 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) man days per year. The average salary is approximately $30 per hour for a cost of $11,760 per year.

CONCLUSION The total time saved on both units 1 & 2 where the plants would be in a condition where a single failure would cause a safeguard actuation is 784 hours0.00907 days 0.218 hours 0.0013 weeks 2.98312e-4 months or 98 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days. The operator distraction time saved would be 196 hours0.00227 days 0.0544 hours 3.240741e-4 weeks 7.4578e-5 months or 24.5 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days.

i The total manhour savings for both units would be 3920 man hours or 490 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days at a cost of $98,000 in instrument mechanic time. The review time savings would be 523 manhours or 65.33 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) man days for a savings of $15,690.

The data collected and reviewed (attachment 1) shows these selected loops to be highly reliable. Extending the frequency to quarterly would have the previously covered positive benefits and would not jeopardize the overall reliability of the plant safety systems.

The plant will maintain a periodic assessment program to guarantee that the systems specified maintain their high reliability. This will include review of SI packages, and repair or replacement of components when problems occur.

f

TVA-SQN-TS-36 Changs No. 3 Sequoyah Nuclear Plant Justification for Proposed Technical Specifications This request encompasc2s 49 instructions in total. There are a number of considerations to be addressed.

1. Each instruction requires an average of 1.0 hour0 days 0 hours 0 weeks 0 months with the loop actually removed from service. This totals 588 hours0.00681 days 0.163 hours 9.722222e-4 weeks 2.23734e-4 months per year, per unit, that the plant is in a trip condition. In other words this is 73.5 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days with the plant in a compromised state.

The proposed change would delete 392 hours0.00454 days 0.109 hours 6.481481e-4 weeks 1.49156e-4 months or 49 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days from the number now required. This would remove 2/3 of the time when a single plant failure could cause a safeguard actuation, thereby, improving plant reliability.

The removal of instrument loops from service for the purpose of testing challenges the safeguards actuation system. We have had several occurrences of safety injection and reactor trip actuations directly related with the performance of surveillance instructions. We believe that by reducing the number of challenges to the safeguards systems, in our test program, we can reduce the possibility of inadvertently challenging our safeguard systeam.

2. Each instruction performed requires interface with the unit operator.

There is also the problem with status lights and indications that are associated with the loop being tested.

A. The operator must spend approximately 15 minutes reviewing and approving each instruction. This averages out to 147 hours0.0017 days 0.0408 hours 2.430556e-4 weeks 5.59335e-5 months or 18.375 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days a year when he is distracted from his vital duties. The proposed change would return 98 hours0.00113 days 0.0272 hours 1.62037e-4 weeks 3.7289e-5 months or 12.25 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) days of the operators valuable time per year.

B. While the loop being tested is removed from service the associated trip status lights and indicators are in an abnormal condition. The times on this are as described in item J1. Although the operators are trained to work with this type of situation it is feasible to consider it contributing to an improper decision at a critical moment.

3. We are expending large quantities of the available instrument mechanic and engineering time to perform and review the monthly functional tests.

A. The average instruction requires approximately 2.0 hours0 days 0 hours 0 weeks 0 months to perform.

The minimum number of people assigned is 2 and normally it is 3. It will take 2.5 persons assigned as average. This vicids 2940 manhours or 367.5 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) man days per unit per year to perform these 49 instructions. At an average salary of $25 per hour, this is a cost of $73,500 per year. The proposed change would reduce the cost for performing these instructions to $24,500. More importantly it would free 1960 manhours or 245 (8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ) man days for a much needed plant secondary preventive maintenance program.

One additional factor is that the work load associated with the monthly testing is so great that many times they are performed on overtime. This creates budgetary problems and manpower problems.

B. All instructions perforned must be reviewed by the senior instrument I mechanic foreman, the instrument engineer, the instrument assistant supervisor, and plant QA.

{

DATA COLLECTED ON SELECTED SQN FUNCTIONAL TEST-Note: The word tolerance used in these papers refers to manufacturer tolerance which is more restricting than technical specification tolerance.

I. Pressurizer Pressure Loops: IMI-99-FT 4.1, 4.2, 4.3, 4.4 for channels I, II, III, & IV.

A. FT 4.1: 13 instructions reviewed (13 consecutive monthly performances)

1. 1-20-81 PB-455A (high pressure reactor trip) was not out of tolerance but adjusted closer to desired value.

B. FT 4. 2: 12 instructions reviewed (12 consecutive monthly performances)

1. There were no changes required. .

C. FT 4.3: 13 instructions reviewed (13 consecutive monthly performances)

1. 10-11-81 PB-457C (low pressure reactor trip) was not outside of tolerance but adjusted closer to desired value.

D. FT 4.4: 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

Conclusion:

In total, 51 consecutive Ferformances of pressurizer pressure monthly FTs were reviewed. There were two minor calibrations made to bring bistable setpoints closer to the desired value.

II. Pressurizer Level Loops: IMI-99-FT 5.1, 5. 2, 5. 3 for channels I, II, & III.

A. FT 5.1: 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

B. FT 5.2: 12 instructions reviewed (12 consecutive monthly performances)

1. There were no changes required.

C. FT 5.3: 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

Conclusion:

In total, 38 consecutive performances of pressurizer level monthly FTs were reviewed. There were no calibrations required.

III. Reactor Coolant System Flow Loops: IMI-99-FT-6.1, 6. 2, 6. 3, 6.4, 6. 5, 6. 6, 6.7, 6.8, 6.9, 6.10, 6.11, 6.12 for four loop plant channels I, II, & III in each loop.

A. FT 6.1, 6.4, 6.7, & 6.10 (loops 1, 2, 3, & 4 protection set I): 13 instructions reviewed (13 consecutive monthly performances).

1. There were no changes required.

B. FT 6.2, 6.5, 6.8, & 6.11 (loops 1, 2, 3, & 4 protection set II): 12 instructions reviewed (12 consecutive monthly performances).

1. 2-25-81 FB-415 (flow loop 1 protection set II low flow reactor trip) was not outside tolerance but adjusted closer to desired value.

C. FT 6.3, 6.6, 6.9, & 6.12 (loops 1, 2, 3, & 4 protection set III): 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

Conclusion:

In total, 152 consecutive performances of reactor coolant flow monthly FTs were reviewed. There was one minor calibration made to bring bistable setpoints closer to the desired value.

IV. Steam Generator Level _ Loops: IMI-99-FT 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 7.10, 7.11, 7.12 for four loop plant channels I, II, III, IV in each loop.

A. FT 7.6 & 7.9 (protection set I): 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

B. FT 7.3 & 7.12 (protection set II): 12 instructions reviewed (12 consecutive monthly performances) i 1. There were no changes required.

C. FT 7.2, 7.5, 7.8, 7.11 (protection set III): 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

D. FT 7.1, 7.4, 7.7, 7.10 (protection set IV): 13 instructions reviewed

1. There were no changes required.

i

Conclusion:

In total, 154 consecutive performances of steam generator level monthly FTs were reviewed. There was no necessity for any recalibration.

V. Steam Generator Mismatch: IMI-99-FT 8.1, 8. 2, 8. 3, 8. 4, 8.5, 8. 6, 8. 7, 8. 8 for four loop plant channels I & II in each loop.

A. FT 8.1, 8.2, 8.3, 8.4 (protection set I) 14 instructions reviewed (14 consecutive monthly performances)

1. 3-18-81 FB-522B: Bistable not outside tolerance but calibrated to bring it closer to the desired value.

2. 10-7-81 FB-542B: Bistable no. outside tolerance but calibrated to bring it closer to the desired value.

, B. FT 8.5, 8.6, 8.7, 8.8 (protection set II) 12 instructions reviewed (12 consecutive monthly performances)

1. 6-18-81 FB-513B: Bistable at tolerance, recalibrated to desired value.

2. 10-16-81 FB-533B: Bistable not out of tolerance but calibrated to bring closer to desired value.

3. 12-30-81 FB-513B: Bistable at tolerance recalibrated to desired value.

Conclusion:

In total,104 consecutive performances of steam generator flow mismatch monthly FTs were reviewed. There were no components outside tolerance but 5 bistables were recalibrated to bring them closer to the desired value.

VI. Steam Pressure Deviation: IMI-99-FT 9.1, 9.2 (protection sets III & IV)

A. FT 9.1 (protection set III): 13 instructions reviewed (13 consecutive monthly performances)

l. There were no changes required.

B. FT 9.2 (protection set IV): 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

Conclusion:

In total, 26 consecutive performances of steam generator pressure deviation monthly FTs were reviewed. There were no components requiring recalibration.

VII. Containment Pressure: EdI-99-FT 16.1, 16.2, 16.3, 16.4 four channels, protection sets I, II, III, IV A. FT 16.1 (protection set I): 14 instructions reviewed (14 consecutive monthly performances)

1. 1-27-81 PB-937A (high-high containment pressure) was not outside tolerance, but was adjusted closer to the desired value.

B. FT 16.2 (protection set II): 12 instructions reviewed (12 consecutive monthly performances)

1. There were no changes required.

C. FT 16.3 (protection set III): 13 instructions reviewed (13 consecutive monthly performances)

1. There were no changes required.

D. FT 16.4 (protection set IV): 13 instructions reviewed (13 consecutive monthly performances)

1. 10-23-81 PB-934A (high-high containment pressure) was not outside tolerance, but was adjusted clcser to desired value.

Conclusion:

In total, 52 consecutive performances of containment pressure monthly FTs were reviewed. There were two minor calibrations made to bring bistable setpoints closer to the desired value.

VIII. NIS Power Range: IMI-99-PRM-FT 41, 42, 43, 44 four channels, protection sets I, II, III, IV A. FT 41 (protection set I): 11 consecutive performances reviewed l 1. No changes required.

B. FT 42 (protection set II): 11 consecutive performances reviewed

1. No changes required.

C. FT 43 (protection set III): 11 consecutive performances reviewed

1. No changes required.

D. FT 44 (protection set IV): 11 consecutive performances reviewed

1. No changes required.

Conclusion:

In total, 44 consecutive performances of NIS power range monthly FTs were reviewed. There were no recalibrations required.

a .4J. s,-4m _ . ~ - _ .. e a w ENCLOSURE 4 i

SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATIONS TVA-SQN-TS-36 CHANGE NO. 4 4

CHANGES TO REFLECT INSTALLATION OF PERMANENT HYDROGEN MITIGATION SYSTEM i

4 1

,.- , - - - , -,. , ,. , . . . . -,,r. , m,--- - - - - , - . . , - - -

-._.-- - ,-- --- .-.--- - - - ,.------~---

CONTAINMENT SYSTEMS llYDROCEN MITIGATION SYSTEM LIMITING CONDITION FOR OPERATION 3.6.4.3 The primary containment hydrogen mitigation system shall be operable.

APPLICABILITY: MODES 1-and 2.

ACTION With one train of hydrogen mitigation system inoperable, restore the inoperable train to OPERABLE status within 7 days or increase the surveillance interval of S.R. 4.6.4.3 from 92 days to 7 days on the operable train until the inoperable train is returned to OPERABLE status.

SURVEILLANCE REQUIREMENTS 4.6.4.3 The hydrogen mitigation system shall be demonstrated OPERABLE:

a .' At least once per 92 days by energizing the supply breakers and verifying that at least 62 of 64 igniters are energized.*

l

h. At least once per 18 months by verifying the cleanlineas of each igniter by a visual inspection. .

l

Inoperable igniters must not be on corresponding redundant circuits which provide coverage for the same region.

I l

SEQUOYAll UNIT 1 3/4 6-25a

TVA-SQN-TS-36 Change No. 4 Sequoyah Nuclear Plant JUSTIFICATION FOR PROPOSED TECHNICAL SPECIFICATIONS As required by Sequoyah Nuclear Plant unit 1 operating license condition 2.C(22).D, TVA is required to install a permanent hydrogen mitigation system. These changes reflect the installation of the permanent system.

The permanent system hydrogen mitigation system is a two train system with 32 igniters in each train.

The permanent hydrogen mitigation system employs controlled ignition to mitigate the effects of hydrogen during potential degraded core accidents or class 9 accidents. The containment structures and key equipment have been shown by analysis oc testing to survive the pressure and temperature loads from selected degraded core accidents and to continue to function.

The extensive research program has confirmed our analytical assumptions, demonstrated equipment survivability and shown that controlled ignition can ir4eed mitigate the effects of hydrogen releases in closed vessels. The permanent hydrogen mitigation system is an adequate hydrogen control system that would perform its intended function in a manner that provides adequate safety margins.

1

i ENCLOSURE 5 SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATIONS TVA-SQN-TS-36 CHANGE NO. 5 ADDITION OF SECOND LEVEL OF UNDERVOLTAGE PROTECTION b

i i

I-t i

i l

i i

l' l

TAELE 3.3-3 (Continued), .

i ENGillEERED SAFETY FEATURE ACTUATI0ff SYSTEH INSTRifNENTATION '

. HIfilHUM TOTAL NO. CilANilELS CilAllflELS APPLICABLE

$ OF CF'ANilELS TO TRIP OPERABLE H0 DES ACTION 8 FUNCTIONAL UNIT f 7. LOSS OF POWER E a. 6.9 kv Shutdown Board Z -Loss of Voltage

" 1 loss of 2/ shutdown 1, 2, 3, 4 20*

1. Start Diesel 2/ shutdown Generators board voltage on board any shutdown board

2. Load Shedding 2/ shutdown 1/ shutdown 2/ shutdown 1)2,3,4 20*

board board board b .' 6.9 kv Shutdown Board

. Degraded Voltage .

w 1. Voltage Sensors 3/ shutdown 2/ shutdown 2/ shutdown 1, 2, 3, 4 20*

, 2 board board board

2. Diesel Generator 2/ shutdown 1/ shutdown 1/ shutdown 1,2,3,4 20*

" board board board Start and Load Shedding Timer

3. SI/ Degraded 2/ shutdown 1/ shutdown 1/ shutdown 1, 2, 3, 4 20*

Voltage Enable board board board <

Timer

8. ENGINEERED SAFETY FEATURE ACTUATIDH SYSTEM INTERLOCKS

a. Pressurizer Pressure - 3 2 2 1, 2, '3 22a Hot P-11 ,,

3 1,2,3 22b

b. T avg

- P-12 4 2 3/ loop 2/ loop 3/ loop 1, 2 22c

c. Steam Generator Level P-14 any loop

E!

iS TABLE 3.3-3 (Continued) o g

SE ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION E MINIMUM

TOTAL NO. CliANNELS CilANNELS APPLICABLE g

TO TRIP OPERABLE HODES ACTION FUNCTIONAL UNIT OF CHANNELS f

9. AUTOMATIC SWITCHOVER TO CONTAINMENT SUHP 2 3 1, 2, 3, 4 18 A. RWST Level - Low 4 u

COINCIDENT WITH Containment Sump 18

];

2 3 1,2,3,4 w

Level - High 4 L AND Safety Injection (See 1 above for Safety Injection Requirements)

E 4

Manual switchover of RHR pump suction from the RWST to containment sunp will

. Note: be employed until containment sump level indicators are returned OPERABLE.

Automatic switchover is not required OPERABLE during the interim. This note

~

will remain in effect for a period not to exceed 30 days (July 18,1982). ,I

TABLE 3.3-4 (Continued) m"

( ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS ,

FUNCTIONAL UNIT TRIP SETPOINT ALLOWABLE VALUES E 6. AUXILIARY FEEDWATER

a. Manual Not Applicable Not Applicable

[

b. Automatic Actuation Logic Not Applicable Not Applicable

c. Main Steam Generator Water Level-low-low > 21% of narrow range > 20% of narrow range Instrument span each Instrument span each steam generator . steam generator

d. S.I. See 1 above (all SI Setpoints)

e. Station Blackout 0 volts with a 5.0 second 0 volt's with a 5.0 1 1.0 second w time delay time delay s

f. Trip of Main Feedwater N.A. N.A. *

{

" g.

Pumps Auxiliary Feedwater Suction 2 2 psig (motor driven pump) 1 1 psig (mptor driven pump)

Pressure-Low 1 6.5 psig (turbine driven 3 5.5 psig (turbine driven pump) pump)

7. LOSS OF POWER

a. 6.9 kV Shutdown Board Undervoltage-Loss of Voltage

1. Start of Diesel Generators 0 volts with a 0 volts with a 1.5 second time 1.5 1 0.5 second time delay delay

2. Load Shedding 0 volts with a 0 volts with a 5.0 second time delay 5.0 1 1.0 second time delay

.O

TABLE 3.3-4 (Continued) y ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS s

FUNCTIONAL UNIT TRIP SETPOINT ALLOWABLE VALUES 7

C

b. 6.9 kv Shutdown Board- Degraded Voltage

1. Voltage Sensors 6560 volts 6560 volts i 33 volts

2. Diesel Generator Start and Load Shed Timer 300 seconds 300 seconds i 15 seconds

3. SI/ Degraded Voltage Logic Enable Timer 11 seconds 11 seconds 1 0.6 seconds Y '

U e

8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCKS .

a. Pressurizer Pressure $ 1980 psig Manual Block of Safety Injection P-11 5 1970 psig OO

TABLE 3.3-S (Contir.ued)

ENGINEEREO SAFETY FEATURES RESPONSE TIMES

('

INITIATING SIGNAL AND FUNCTION RESPONSE TIME IN SECONOS

10. Station Blackout -

a. - Auxiliary Feedwater Pumps 1 60

~.

11. Trip of Main Feedwater Pumps a Auxiliary Feedwater Pumps 1 60

12. Loss of Power

a. 6.9 kv Shutdown Boa _rd - Degraded i 10(10)

Voltage or Loss of Voltage

, j

13. RWST Level-Low Coincident with Containment Sump Level-High and Safety Injection

a. Automatic Switchover to Containment Sump i 250

14. Containment Purge Air Exhaust Radioactivity - High

4

a. Containment Ventilation Isolation i 10(6)

15. Containment Gas Monitor Radioactivity High

a. Containment Ventilation Isolation i 10(6)

16. Containment Particulate Activity High

a. Containment Ventilation Isolation 1 10(6)

SEQUOYAH - UNIT 1 3/4 3-32 ad

INSTRUMENTATION TABLE 3.3-5 (Continued)

TABLE NOTATION (1) Diesel generator starting and requence loading delays included. Response time limit includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps, SI and RHR pumps.

(2) Using air operated valve (3) Valve FCV-70-143 is an exception to the respon'se time shown in the table and will have the following values in seconds for the initiating signal and function indicated.

2.d. 61((8)/71(9) 3.d. 62 8) 4.d. 61(8)f7)(9) 5.d. 64(0) 6.d. 61(8)j/74((9)

7) 9)

(4) On 2/3 any Steam Generator ,

j (5) On 2/3 in 2/4 Steam Generator (6) Radiation detectors for Containment Ventilation Isolation may be excluded from Response Time Testing.

(7) Diesel generator starting and sequence loading delays not include.d.

Offsite power available. Response time limit includes opening of valves-to establish SI path and attainment of discharge pressure for centrifugal charging pumps.

(8) Diesel generator starting and sequence loading delays not included.

Response time limit includes operating time of valves.

(9) Diesel generator starting and sequence loading delays included. Response time limit includes operating time of valves.

(10) The response time for loss of voltage is measured from the time voltage is lost until the time full voltage is restored by the diesel. The response time for degraded voltage is measured from.the time the load shedding signal is generated, either from the degraded voltage or the SI enable timer, to the time full voltage is restored by the diesel.

The response time of the timers are covered by the requirements on their setpoints.

SEQUOYAH - UNIT 1 3/4 3-33 ar

TABLE 4.3-2 (Cond nuedl ,

S ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION j' E - SURVEILLAf4CE REQUIREltENTS

i. E

' CHANNEL H0 DES IN WHICH CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE E REQUIRED CALIBRATION TEST O FUNCTIONAL UNIT CHECK . .

w '

Main Steam Generator Water S, R H 1,2,3

c. ~

Level-Low-low

d. S.I. See 1 above (all SI surveillance requirements)

e. Station Blackout N.A. R N.A. 1, 2, 3 N.A. N.A. 1, 2 f3 Trip of Hain Feedwater R

,, Pumps N.A. M 1, 2, 3

g. Auxiliary Feedwater Suction R .

Pressure - Low R

u

7. LOSS OF POWER ,

u a. 6.9 kv Shutdown Board - ,

0 Loss of Voltage .

1, 2, 3, 4

1. Start Diesel cenera.: ors S R H

2. Load Shedding, 5 . R N.A. ,

1, 2, 3, 4

b. 6.9 kv Shutdown Board -

Degraded Voltage

1. Voltage sensors S R M 1, 2, 3, 4

2. Diesel Generators N.A. R N.A. 1, 2, 3, 4 Start and Load Shedding Timer

3. SI/ Degraded Voltage N.A. R N.A. 1, 2, 3, 4 Logic Timer

9 TABLE 4.3-2 (Continued) .

v, E

c ENGINEERED SAFETY FEATURE ACTUATION SYSTEH INSTRUMENTATION -

SURVEILLANCE REQUIREMENTS y -

x .

- ' CHANNEL MODES IN WHICH CHANNEL FUNCTIONAL SURVEILLANCE E CHANNEL CHECX CALIBRATION TEST REQUIRED Z

FUNCTIONAL UNIT _

w .. -

r

8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCKS Pressurizer Pressure, N.A. R (4) N.A. 1, 2, 3 a.

P-11 ,

R (4) N.A. 1, 2, 3

b. N.A.

Tavg, P-12 .

N.A. R (4) H.A. 1, 2 u, c. Steam Generator 2: Level, P-14 Y'

9. " AUTOMATIC d.o;cHOVER,TO h .

O ;

CONTAINMENT SUMP ./ ,

a. RSWT Level - Low S 'R H 1, 2, 3, 4 COINCIDENT WITH '

Containment Sump Level - High S R H 1,2,3,4 AND Safety injection (See 1 above for all Safety Infection Surveillance Requirements)

Note: Manual switchover of RHR pump suction from the RWST to containment sump will be employed until containment sump level indicators are returned OPERABLE.

Automatic switchover is not required OPERABLE during the interim. This note l

will remain in effect for a period not to exceed 30 days (July 18,1982).

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

d. At least once per 18 months by verifying that the battery capacity is adequate to supply and maintain in OPERABLE status all of the actual or simulated emergen:y loads for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months when the battery is subjected to a battery service test.

e. At least once per 60 months by verifying that the battery capacity is at least 82% of the manufacturer's rating when subjected to a performance discharge test. Once per 60 month interval, this perfo'rmance discharge test may be performed in lieu of the battery service test.

f. Annual performance discharge tests of battery capacity shall be given to any battery that shows signs of degradation or has reached 85% of the service life expected for the application. Degradation is indicated when the battery capacity drops more than 10% of rated capacity from its average on previous performance tests, or is below 90% of the manufacturer's rating.

SEQUOYAH - UNIT 1 3/4 8-13

s TABLE 3.3-3 { Continued),

ENGIt1EERED SAFETY FEATURE ACTUATI0tl SYSTEH IllSTRU!IEllTATION .

i HitlIHUM u, CHANilELS CilAftilELS APPLICADLE TOTAL !!0. H0 DES ACTION 19 OF CHAfillELS TO TRIP OPERABLE 8 FUNCTIONAL UNIT Y

7. LOSS OF POWER i

E a. 6.9 kv Shutdown Board ,

--Loss of Voltage

l 20*

1 loss of 2/ shutdown 1, 2, 3, 4 h' 1. Start Diesel 2/ shutdown board voltage on board Generators any shutdown board 2/ shutdown 172,3,4 20*

2. Load Shedding -

2/ shutdown 1/ shutdown board board board bJ 6.9 kv Shutdown Board

. Degraded Voltage .

2/ shutdown 2/ shutdown 1, 2, 3, 4 20*

w 1. Voltage Sensors 3/shutd own 32 board board board w 1, 2, 3, 4 20*

E 2. Diesel Generator 2/ shutdown 1/ shutdown 1/ shutdown ~

Start and Load board board board Shedding Timer 1/ shutdown 1/ shutdown 1, 2, 3, 4 20*

3. SI/ Degraded 2/ shutdown Voltage Enable board board board Timer .

8. ENGINEERED SAFETY FEATURE ACTUATI0tt SYSTEM IllTERLOCKS

~

2 2 1, 2, 3 22a

a. Pressurizer Pressure - 3 Not P-11 ..

2 3 1,2,3 22b

b. 4 T,yg - P-12 3/ loop 2/ loop 3/ loop 1, 2 22c

c. Steam Generator Level P-14 any Icop

p - -

hh TABLE 3.3-3 (Continued) it

- ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION E HINTHUM q APPLICABLE TOTAL NO. CilANNELS CilANNELS

" TG TRIP OPERABLE HODES ACTION FUNCTIONAL UNIT OF CHANNELS

9. AUTOMATIC SWITCHOVER TO

- f CONTAINHENT SUMP A. RWST Level - Low 4 2 3 1,2,3,4 18 u, COINCIDENT WITH 3: Containment Sump u, Level - High 4 2 3 1,2,3,4 18 h AND (See 1 above for Safety Injection Requirements) 7 Safety Injection

~~~~

, Note: Manual switchover of RHR pump suction from the RWST to containment sump will be employed until containment sump level indicators are returned OPERABLE.

Automatic switchover is not required OPERABLE during the interim. This note

'will remain in effect for a period not to exceed 30 days (July 18,1982). ,

'l

TABLE 3.3-4 (Continued)

M ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENiATION TRIP SETPOINTS

($ '

TRIP SETPOINT ALLOWASLE VALUES FUNCTIONAL UNIT 7

E 6. AUXILIARY FEEDWATER

a. Manual Not Applicable Not Applicable u Not Applicable

b. Automatic Actuation Logic Not Applicable

c. Main Steam Generator Water Level-low-low > 21% of narrow range > 20% of narrow range Tnstrument span each Instrument span each steam generator steam generator

d. S.I. See 1 above (all SI Setpoints)

e. Station Blackout 0 volts with a 5.0 second 0 volts with a 5.0 1 1.0 second time delay time delay ga

f. Trip of Main Feedwater M.A. N.A. *

{

g-Pumps Auxiliary Feedwater Suction 1 2 psig (motor driven pump) 1 1 psig (optor driven pump)

Pressure-Lew 2 6.5 psig (turbine driven 1 5.5 psig (turbine driven pump) pump)

7. LOSS OF POWER

a. 6.9 kv Shutdown Board Undervoltage-Loss of Voltage

1. Start of Diesel Generators 0 volts with a 0 volts with a 1.5 second time 1.5 1 0.5 second time delay delay

2. Load Shedding 0 volts with a 0 volts with a '

_ _ _ 5.0 second time delay 5.0 1 1.0 second time delay ,

e.

\

y, ; ,7 TABLE 3.3-4 (Continued) n, jj ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS FUNCTIONAL UNIT TRIP SETPOINT ALLOWABLE VALUES 7

=

1 .

~

b. 6.9 kv Shutdown Board- Degraded Voltage

1. Voltage Sensors 6560 volts 6560 volts + 33 volts

2. Diesel Cencrator Start and Load Shed Timer 300 seconds 300 seconds + 15 seconds

3. SI/ Degraded Voltage Logic

&#, Enable Timer 11 seconds 11 seconds + 0.6 seconds a

T

E$

O

8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCKS .

a. Pressurizer Pressure 5 1980 psig Manual Block of Safety Injection P-11 5 1970 psig

.e 4

o .

TABLE 3.3-5 (Continued)

ENGINEERED SAFETY FEATURES RESPONSE TIMES ('

,I_NITIATING SICNAL AND FUNCTION RESPONSE TIME IN SECONDS

10. Station Blackout ,

a. Auxiliary Feedwater Pumps 1 60

11. Trip of Main Feedwater Pumps a Auxiliary Feedwater Pumps 5 60

12. Loss of Power

a. 6.9 kv Shutdown Board - Degraded i 10(10)

Voltage or Loss of Volta'ge

. I J

13. RWST Level-Low Coincident with Containment Sump Level-High and Safety Injection

a. Automatic Switchover to Containment Sump i 250

14. Containment Purae Air Exhaust

Radioactivity - High *

a. Containment Ventilation Isolation i 10(6)

15. Containment Gas Monitor .

Radioactivity High

a. Containment Ventilation Isolation i 10(6)

16. _ Containment Particulate Activity High

a. Containment Ventilation Isolation i 10(6)

SEQUOYAH - UNIT 2 ,

3/4 3-32 --

GO

INSTRUMENTATION TABLE 3.3-5 (Continued)

TABLE NOTATION (1) Diesel generator starting and requence loading delays included. Response time limit includes opening of valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps, SI and RHR pumps.

(2) Using air operated valve (3) Valve'FCV-70-143 is an exception to the respon'e s time shown in the table and will have the fo119 wing values in seconds for the fattiating signal and function indicated.

2.d. 61(8)f7)(9) 3.d. 62 50)

I I9) 4.d. 61(035.d.

f74 6.d. 61 8)f7)(9) 64(8)/71(9)

(4) On 2/3 any Steam Generator (5) On 2/3 in 2/4 Steam Generator (6) Radiation detectors for Containment Ventilation Isolation may be excluded from Response Time Testing.

(7) Diesel generator starting and sequence loading delays not includep.

Offsite power available. Response time limit includes opening of' valves to establish SI path and attainment of discharge pressure for centrifugal charging pumps.

(8) Diesel generator starting and sequence loading delays not included.

Response time limit includes operating time of valves.

(9) Diesel generator starting and sequence loading delays included. Response time limit includes operating time of valves.

(10) The response time for loss of voltage is-measured from the time voltage is lost until the time full voltage is restored by the diesel. The response time for degraded voltage is measured from the time the load shedding signal is generated, either from the degraded voltage or the SI enable timer, to the time full voltage is restored by the diesel.

The response time of the timers are covered by the requirements on their setpoints.

SEQUOYAH - UNIT 2 3/4 3-33

TABLE 4.3-2 (Continuedl m .

t ENGINEERED SAFETY FEATURE ACTUATION SYSTEH INSTRUMENTATION t, y - SURVEILLANCE REQUIRE 11ENTS x .

' CHANNEL H0 DES IN WHICH CHANNEL FUNCTIONAL SURVEILLANCE E CHANNEL CHECK CALIBRATION TEST . REQUIRED O FUNCTIONAL UNIT H 1, 2, 3

c. Main Steam Generator Water S, R Level-Low-Low

d. S. I. See 1 above (all SI surveillance requirements)

N.A. 1, 2, 3

e. Station Blackout N.A. R

^' '

1, 2

~

f. Trip of Main Feedwater N.A. N.A. R ,

Pumps M 1, 2, 3

g. Auxiliary Feedwater Suction N.A. R .

Pressure - Low ,

t' 7. LOSS OF POWER ,

z. -

w a. 6.9 kv Shutdown Board -

Loss of Voltage ,

S R H 1, 2, 3, 4

1. Start Diesel Genera ors 1, 2, 3, 4

2. Load Shedding, S .

R N.A. ,

b. 6.9 kv Shutdown Board -

Degraded Voltage

1. Voltage sensors S R M 1,2,3,4

2. Diesel Generators N.A. R N.A. 1, 2, 3, 4 Start and Load Shedding Timer

3. SI/ Degraded Voltage N.A. R N.A. 1,2,3,4 Logic Timer

TABLE 4.3-2(Continuedl ENGINEERED SAFETY FEATURE ACTUATION SYSTEH INSTRUMENTATION

,5URVEILLAllCE REQUIRElEllIS

' CHANNEL H0 DES IN WHICH CHANNEL CllANNEL FUNCTIONAL SURVEILLAllCE E

CALIBRATION TEST REQUIRED O FUNCTIONAL UNIT CHECK .

u _.

- 8. ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INTERLOCK 5

a. Pressurizer Pressure, N.A. R (4) N.A. 1, 2, 3 P-11 ,

b. N.A. R (4) N.A. 1, 2, 3 T,yg, P-12 .

c. Steam Generator H.A. R (4) H.A. 1, 2 m

2 Level, P-14 Y' ~

u 9. AUTOMATIC '5WITCHOVER TL i. .

CONTAINMENT SUMP ./ ,

a. R5WT Level - Low 5 '

'R H 1, 2, 3, 4 COINCIDENT WITH '

Containment Sump Level - High 5 R H 1,2,3,4 AND Safety injection (See 1 above for all Safety Injection Surveillance Requirements)

Note: Manual switchover of RHR pump suction from the RWST to containment sump will be employed until containment sunp level indicators are returned OPERABLE.

Automatic switchover is not required OPERABLE during the interim. This note will remain in effect for a period not to exceed 30 days (July 18,1982).

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

d. At least once per 18 months by verifying that the battery capacity is adequate to supply and maintain in OPERABLE status all of the actual or simulated emergency loads for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months when the battery is subjected to a battery service test.

e. At least once per 60 months by verifying that the battery capacity is at least 82% of the manufacturer's rating when subjected to a performance discharge test. Once per 60 month interval, this performance discharge test may be performed'in lieu of the battery service test.

f. Annual performance discharge tests of battery capacity shall be given to any battery that shows signs of degradation or has reached 85% of the service life expected for the application. Degradation is indicated when the battery capacity drops more than 10% of rated capacity from its average on previous performance tests, or is below 90% of the manufacturer's rating.

SEQUOYAH - UNIT 2 3/4 8-13

TVA-SQN-TS-36 Change No. 5 Sequoyah Nuclear Plant Justification for Proposed Technical Specifications These technical specifications are being revised to reflect the addition of a second level of over and undervoltage protection required by operating license conditions 2.C(18).c (unit 1) and 2.C(11).b (unit 2).

The second level of undervoltage relays operate if a 6900-volt shutdown board bus voltage drops below the level required to successfully start all the safety-related equipment that would be required for the design basis accident. The relays will initiate 3 different time delay sequences. The first sequence of 30 seconds will ride through normal system transients before annunciating in the main control room. The second sequence of 10 seconds is short enough to allow safety-related equipment to be powered within the time required by the safety analysis. At the end of 10 seconds, if a safsty injection has been initiated or is subsequently initiated, the shutdown board will transfer to its diesel generator.

The third time delay of five minutes is long enough to allow operator action to correct the undervoltage condition but not allow damage to connected safety-related equipment. At the end of the 5-minute delay, the shutdown board will transfer to its diesel if voltage has not been corrected. Since the loss of voltage relays on normal feeder only are set at 80 percent of nominal for four seconds, the band of voltages that a nonaccident degraded voltage condition can exist is from 80-95 percent of nominal for five minutes. At 80 percent of nominal, the voltage at the terminals of running motors will not drop below 71 percent of motor-rated voltage. NEMA class B motors will not stall out or be damaged above this point for the time delay of five minutes. Also, during the five minute time delay, the 125V do vital battery boards could be powered by the batteries instead of the battery chargers. However, the vital batteries have sufficient capacity to meet this requirement as well as meet the original design requirements as identified in section 8.3.2 or the Sequoyah FSAR.

Attached is supplementary technical information that provides the basis for our justification.

A2TAOBOFT

'hmnessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2 Degraded Voltage Relaying Supplanentary Technical Information I

i i

G 061273.01 . -

4 I

00mDirs 1.0 Introduction 2.0 Design Base Criteria 3.0 Evaluation 3.1 Existing Undervoltage Protecticn 3.2 Proposed Modifications 3.3 Discussion 4,. 0 Conclusions 5.0 References 6.0 Appendix 6.1 Appendix A " Voltage and Time Delay Analysis" 6.2 Appendix B " Technical Specification Changes" e

h 8

SUPPLEMENTARY TEWNICAL INEORMATION DEGRADED GRID PROI1DCTION EM CLASS 1E POWER SYSTDiS SEQUDYAH NUGEAR PIANT 1.0 INTR 2 0CTION On July 28, 1978, the NRC requested WA to assess the susceptibility of the safety-related electrical equipnent at Sequoyah Nuclear Plant to a sustained voltage degradation of the offsite source and inter-action of the offsite and onsite energency power systems. FSAR -

question 8.33 contained four positions with which the current design of the plant was to be canpared. After comparing the current design to the staff positions, WA was required to either propose modifications to satisfy the positions and criteria or furnish an analysis to substantiate that the existing facility has equivalent capabalities.

By this subnittal, WA is proposing certain design modifications to satisfy the criteria and staff positions. The modifications include installation of a second-level undervoltage protection system for the Class 1E equipnent. 'Ihe NRC required that the setpoint, surveillance requirements, test require:nents, and allowable limits were to be included by WA in the plant technical specifications.

2.0 DESIGN BASE CRITERIA The design base criteria that wer e applied in determining the acceptability of the systen modifications to protect the safety-related equipnent from t sustained degradation of offsite grid are:

1. General Design Criterion 17 (GDC 17), " Electrical Power Systems,"

of appendix A, " General Design Criteria for Nuclear Power Plants,"

of 10 CFR 50.

2. IEEE Standard 279-1971, " Criteria for Protection Systems for Nuclear Power Generating Stations."

3. IEEE Standard 308-1974, " Class 1E Power Systems for Nuclear Power Generating Stations."

4. Staff positions as detailed in FSAR question 8.33 dated July 28, 1978.

5. ANSIStandardC84.1-1977,"YoltageRatingsforElectricalPower Systems and Equipnent (60 HZ)."

M 5

3.0 EVAWATION Wis section provides, in subsection 3.2, a description of the propored modifications for the second-level undervoltage protection; and, in subsection 3.3, a discussion of how the proposed modifications meet the design base criteria.

3.1 Mntim Undervoltace Protection _ The present design uses three single induction disks, inverse time undervoltage relays with a setpoint of 70 percent of nominal for each 6900V shutdcwn board to detect loss of voltage.

1. A Westinghouse-type CV-7 relay monitors the voltage on the normal feed to the board and will initiate transfer in 2.5 seconds (at zero volts) to the alternate breaker if the alternate supply voltage is greater than 90 percent of nminal '(detected by Westinghouse-type SG relays) . The closure of the alternate breaker is delayed until the residual bus voltage is less than 30 percent of nminal (detected by GE-tyg PAV relays) .

2. A GE-type IAV relay on the 6.9-kV bus initiates the autmatic start sequence of the diesel generator for a sustained loss of voltage for 1.5 seconds (at zero volts) .

3. A second GD-type IAV relay en the 6.9-kV bus for a sustained loss of voltage for a total of five seconds (at zero volts) will initiate load shedding (the normal and alternate feeder ~

breakers are tripped and locked out; all the 6.9-kV motor loads and the major 480V loads are tripped). When the diesel generator set has attained rated speed and voltage (maximum of 10 seconds fra initir.tiun of autmatic start signal), it is automatically connected to the 6.9-kV shutdown board bus.

We return of voltage to the 6.9-kV shutdown board bus initiates logic which connects the required loads in the proper sequence and time.

3.2 theilfication. 'IVA will (1) replace the existing loss of voltage

' relays, on nomal feeder breaker only, with three instantaneous solid-state relays (ITE-type 27H) arranged in a two-out-of-three coincidence logic (see Figure A-II). The logic will energize two timers, either of which will initiate transfer to the alternate, if the alternate supply voltage is greater than 95 percent of nminal by tripping the bus normal supply breaker. n e relays

~~

will have a nminal setpoint of 5520 volts f 1 percent (80% of nminal) with a relay / timer ombined time delay of 4 seconds + 5 percent. We diesel generator starting and load shedding circuitry described in 3.1 -2,-3 will not be modified. (2) To protect the Class lE buses frm a sustained degraded undervoltage, each of the two 6.9kV Class 1E buses per unit will be provided with a set of three instaneous solid-state undervoltage relays (ITE-type 27/59H) . These relays will have a nminal setpoint of 6560Vf 1/2 percent (95% of nminal) . The relays will be arranged in a two-out-of-three coincidence logic I

l l

l

l . .

" to initiate three time delay sequences (see Figure A-I). We first sequence of 30 seconds will ride through normal system voltage transients (motor starts - both safety and nonsafety related) before annunciating the undervoltage in the main control rocan. W e second sequence is short enough t2 allow safety-related equipnent to be powered within the time required by the safety analysis. At the end of 10 seconds if an SIS has been initiated, or is subsequently initiated, the shutdown board degraded voltage relays will initiated load shedding and subsequently transfer the shutdown board to its diesel generator.

The return of bus voltage initiates load sequencing of safety-related equipment. The third time delay is long enough to allow operator action but not result in damage to connected safety-related equipment. At the end of five minutes, the shutdown board will initiate load shedding and subsequently transfer the shutdown board.co its diesel generator if degraded voltage has not been corrected. The error associated with these relay / timers is 10.5 percent.

To protect the Class IE buses from a sustained over-voltage, each of the two 6.9-kV Class IE buses per unit will be provided with a set of three instantaneous solid-state overvoltage relays (ITE-type 59H). Wese relays will be arranged in a one-out-of-three coindence logic which will annunciate in the control rocxu. We relays will have a nominal voltage setpoint of 7260 volts i 1 percent (105 percent of nominal). %e operator will take the action necessary to reduce the voltage.

Load shedding for a loss of bus voltage (670 percent) is being being maintained once the diesel generators are supplying their .

respective buses. Degraded voltage relaying will not open the stan&y supply breaker and will not initiate load shedding and resequencing if a 6900-volt shutdcnn board is supplied by its diesel generator. % e output of these relays is blocked when the.

stan@y breaker is closed. '1VA's bases for this is discussed in l section 3.3.2. .

Proposed changes to the plant's technical specifications, adding the surveillance requirements, allowable limits for the setpoint

' and time delay, and limiting conditions for operation for the second level undervoltage monitors are furnished in appendix B.

An analysis to substantiate the limiting conditions and minimum and maximtsn setpoint limits is furnished in appendix A.

3.3 Discussion 3.3.1 NRC staff position 1 requires that a second level of undervoltage protection for the onsite power qsten be provided. W e position stipulates other circeria that the undervoltage protection must meet. Each criterion is restated below followed by a discussion regarding '1VA's compliance with that criterion.

1. " h e selection of voltage and time setpoints shall be determined fra an analysis of the voltage requirenents of m the safety-related loads at all onsite systan distribution levels."

'1VA's proposed setpoint of 6560 volts at the 6.9-kV bus is 99 percent of the motor-rated voltage of 6.6 kV. nis setpoint reflected down to the 480V buses will be at least 90 percent of the motor-rated voltage during their operation. As the 460-volt motors are the most limiting equipnent in the systen, this setpoint is adequate. See analysis in appendix A for details.

2. "h e voltage protection shall include coincidence logic to preclude spurious trips of the offsite pawer sources."

The prop >ced modification incorporates a two-out-of-three logic' scheme which satisfies this criterion.

3. " h e time delay selected shall be based on the following conditions:

a. The allowable time delay, including margin, shall not exceed the maxinan time delay that is assmed in the FSAR accident analysis." ,

l For a degraded voltage condition simultaneous with a SI actuation, the proposed time delay of 10 seconds, to load shed and connect the diesel generator to the bus does not exceed the wavi== time delay in the accident analysis.

Without the presence of a SI signal, the time delay of l 5 minutes will not be the cause of any damage to the safety-related equipnent. The setpoint is within voltage ranges recmrended by ANSI C84.1-1977.

b. " h e time delay shall minimize the effect of short-duration disturbances fr a reducing the availability of the offsite power source (s) ."

The time delays selected will prevent spurious trips frm the offsite source on starting the largest driven motor loads.

c. "The allowable time duration of a degraded voltage condition at all distribution systen levels shall not result in failure of safety systems or caponents."

ne time delays chosen will not cause any failures of the safety-related egaipnent since the voltage setpoint is within the allowable tolerance of the equipnent-rated voltage.

4. "The voltage monitors shall autmatically initiate the

, disconnection of offsite power sources whenever the voltage setpoint and tin -delay limits have been exceeded."

This criterion is met due to multiple logic sensing of the voltage monitors and redundant timing relays (for the under-voltage scheme).

5. "The voltage monitors shall be designed to satisfy the requirements of IEEE Standard 279-1971."

The proposed modifications are designed to meet the applicable requirements IEEE Standard 279.

6. "The technical specifications shall include limiting

conditions for operation, surveillance requirements, trip setpoints with minimum and maximum limits, and allowable values for the second-level voltage protection monitors."

TVA's proposal for technical specification changes are.

furnished in appendix B.

. 3.3.2 The second NBC staff position raquires "that the system design automatically prevents load shedding of the emergency buses once the onsite sources are supplying power to all sequenced loads. The load shedding must also be reinstated if the onsite breakers are tripped. In the event an adequate basis can be provided for retaining the load-shed feature when loads are energized by the onsite power system, the licensee's bases for the setpoint and limits must be doctanented."

TVA has elected to retain the loss-of-voltage (670 percent) load-shed feature once the diesel generators are supplying their respective buses. IVA's bases for retention of the this feature is that it provides for autcmatic resequencing of the loads following any tenpotary loss of bus voltage.

Since the loss-of-voltage load shedding relay setpoint is fixed at 4860 volts (70 percent of nminal), the starting of the largest driven load will not cause actuation of the load shedding feature. Therefore, the operation of the load shedding relay s stem is:

1. To shed loads to relieve overloading the diesel generator.

2. Allow the diesel gen'erator to recover to rated speed and voltage.

3. Reconnect required loads in the proper sequence.

9 It is WA's position that only mechanical or electrical

,, c mponent failures of the diesel generator could cause the voltage to reach a this level (70 percent) for the time delay required to initiate the loss-of-voltage load shed relays.

Should this occur, the second rc<1undant safety train would safely shut down the unit. We mini _== and ==v4== value of the undervoltage setpoints will be included in the 'Iwchnical Specifications.

3.3.3 W e third NBC staff position requires that certain test requirements be added to the technical specifications. These tests were to demonstrate the full-functional operability and independence of the onsite power sources and are to be performed at least once per 18 nonths during shutdown. The tests are to simulate loss of offsite p wer in conjunction with a safety injection actuation signal and to simulate interruption and subsequenct reconnection of onsite power Sources. .

These recuirements are already met by Sequovah surveillance -

requirements 4.R.1.1.2.d.6 and 4.8.1.1.2.d.7.

3.3.4 he fourth NBC staff position requires that the voltage 1evels at the safety-related buses be optimized for the full load and minimum load conditions that are expected throughout the anticipated range of voltage variations of the power source by appropriate adjustrnent of the voltage tap settings of the intervening transformers. It is required that the adequacy of the design in this regard be verified by actual measurement, and by correlation of measured values with analytical results.

An analysis of sequoyah unit I has been cmpleted and the results sutnitted to A. Schwencer, Chief, Licensing Branch No. 2, fr a our L. M. Mills, Manager, Nuclear Regulation and Safety, on October 3, 1980. These results verified the

, adequacy of our design calculations for the ac auxiliary l power systm used in optimizing the transformer taps for I varying conditions of operation. On April 2,1981, another l letter was sent to your A. Schwencer concerning NRC's i agrement to not repeat the test for our Sequoyah Unit 2.

l Therefore, 'IVA satisfies the requirenents of this position.

t 4.0 CONCIDSICtB _

l

'1VA has detemined that the modifications cmply with the three staff

( psitiens. All the staff's requirenents and design base criteria have

[ been met. W e modifications will protect the Class lE equipnent fr m a sustained degraded voltage condition of the offsite power cource.

The proposed changes to the technical specification adcquately test the system modifications. W e surveilance requirements, limitir.g conditicns for operation, minimum and maximum limits for the trip setpoint, and allowable values meet the intent of the staff psitions.

l

It is therefore concluded that WA's proposed modifications and

,. technical specification changes are adequate. WA intends to incorporate these modifications in the plant design on both units by the end of the first refueling outage of unit 1 and the technical specification changes will be implenented at that time. '1his is in accordance with the requirenents stated in our unit operating license.

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Tennessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2 Degraded Voltage Relaying Suppleraantary Technical Information Appendix A Voltage and Time Delay Analysis 1

s 061273.02 i

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FIGURE B PROGRAM N2DVUN THE PURPOSE OF THIS PROGRAM IS TO EVALUATE THE VOLTAGES ASSOCIATED WITH NORMAL OPERATION.

500-KV SWITCHYARD GERERATOR 1 MAIN TRANSFORMER 24 KV,1220.6MW 3-10, 500-22.5 KV ,

0.9 pf em 420 MVA FOA -

IB 1A UNIT STATION SERVICE TRANSFORMERS N" 2 MVA d/

IC UD 1B hA 6.9 KV UNIT BDS RCP 1B-B 1A-A 6.9 KV SHUTOOWN BDS ERCW

'*0 TOR AND BOARD VOLTAGES MOTOR HP BOARD STARTUP KV MAX. STEADY STATE KV RECOVERY MOTOR BD TIME (SEC) MOTOR BD RCP 6000 UNIT 5956 6120 28 6600 6624 ERCW pp 700 SHUTDOWii 6285 6498 2 6528 6580 CONDITIONS:

1. Generator Voltage at its flinimum of 22.3 kV.

2. USST Voltage Taps at the +2-1/2 Percent Buck Position.

J

FIGURE C F:0 GRAM N2DVUL TriE PURPOSE OF THIS PROGRAM IS TO EVALUATE VOLTAGES ASSOCIATED WITH THE DESIGN-E* SIS ACCIDENT WHILE UNIT CONNECTED.

500-KV SWITCHYARD MAIN TRANSFORMER GENERATOR 1 mm 3-10, 500-22.5 KV, 24 KV,1220.6MW 0.9 pf mm 420 MVA FOA

[w % d UNIT STATION SERVICE TRANSFORMER 22.5-6.9 KV, 34 mm y 21/28 MVA OA/FA *

. . 1 1C ID 18 1A 6.9 KV UNIT BDS 18-B 1A-A 6.9 KV SHUTDOWN BDS

": TOR A"D BOARD VOLTAGES MOTOR HP BOARD BOARD START-UP RECOVERY BOARD STEADY-STATE KV TIME (SEC) gy

LL SI T -

UNIT -

6387 s4 6685 ACTUATED LDADS -

s s4000 SHUTDOWN 6197* s4 6639 CONDITIONS:

1. Generator Voltage at its !!inimum of 22.8 kV.

2. USST Voltage Taps at the +2-1/2 Percent Buck Position.

FIGURE D PROGRAM N2DVCL THE PURPOSE OF THIS PROGRAM IS TO EVALUATE VOLTAGES ASSOCIATED WITH THE DESIGN-BASIS ACCIDENT UNDER THE FOLLOWING CONDITIONS:

1) UNIT 1 LOCA WITH SWITCHYARD ELECTRICAL FAULT.

2) UNIT 2 FULL-LOAD REJECTION STILL UNIT CONNECTED.

3) ONE CSST OUT-0F-SERVICE.

4) 161-KV GRID VOLTAGE AT 162 KV.

5) CSST VOLTAGE TAPS AT THE -5% B0OST POSITION.

161-KV SWITCHYARD COMMON STATION SERVICE TRANSFORMEF

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24/32/40 24/32/40 IA D 1B 6.9 KV UNIT BDS 9

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6.9 KV SHUTDOWN BD 6.9 KV COMMON 00ARD BDS MOTOR AND BOARD VOLTAGES NODE:h MOTOR HP BOARD BOARD START-UP RECOVERY BOARD STEADY-KV TIME (SEC) STATE KV ALL SI } UNIT @ 6577 s4 ACTUATED 4000 7045 J SHUT 00WN 6370 14 6995 LOADS 4000 SHUTDOWN B375 s4 7007

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FIGURE E f

PROGRAM N2FLR2U THE PURPOSE OF THIS PROGRAM IS TO EVALUATE VOLTAGES ASSOCIATED WITH THE WORST CASE COMMON STATION SERVICE TRANSFORMER (CSST) LOADING UNDER THE FOLLOWING CONDITIONS:

1) ONE CSST OUT-0F-SERVICE

2) BOTH UNITS IN FULL-LOAD REJECTION ,

3) 161-XV GRID AT 162 KV

4) CSST VOLTAGE TAPS AT THE -5". B0OST POSITION SYt'80LS : 161-KV SWITCHYARD O- coeutta "oot COMMON STATION SERVICE TRANSFORMER 161-6.9-6.9 KV 34,

"" "" 33/44/55 24/32/40 0A/FA/F0A

O3 24/32/40 2B 2D IB 10 2A 2C 1A IC 6.9 KV 6.9 KV UNIT BDS k2A-A 6.9 KV ~

1A-A B )A ~

2B-B 6.9 KV IB-B

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SHUTDOWN SHUTDOWN BDS BDS BOARD N0DE STEADY-STATE KV UNIT 2 6629 SHUTDOWN 9 6589 SHUTDOWN 7 6585 UNIT 3 6662 SHUTDOWN 8 6618 SHUTDOWN 6 6617 i

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hnnessee valley Authority Sequoyah Nuclear Plant Units 1 and 2 Degraded voltage Relaying Supplementary Technical Information Appendix B .

'nk:hnical Specification Changes J

061273.03 4 .

- .- ~, - ,.-,

- , - . . , , - _ - - . , . , _ , . - - , ,-r-

The justifications for the proposed technical specification changes required for the degraded voltage protection modification are provided below. Marked up copies of the affected page follow.

Page 3/4 3-21 The engineered safety feature actuation system instrumentation for loss of electric power has been modified to include the degraded voltage instrumentation.

Page 3/4 3-27 The setpoints are determined to be adequate for protection based on the study presented in appendix A, " Voltage and Time Delay Analysis," to the degraded voltage report.

Page 3/4 3-32 The footnote was added to the loss of power response time to identify exactly what is measured for the degraded voltage channels. The timers are excluded because the response time is dependent on both the timers selected and the presence of a safety injection (SI) signal. The response will be measured from the time of a signal out of the timers to the time full voltage is restored. This eliminates the need to consider the SI signal and the different timer setpoints. The response time of the timers is covered by the setpoints specified in table 3 3-4.

Page 3/4 3-37 The surveillance requirements are modified to inc?ude testing of the degraded voltage channels. The channel check for the voltage sensors will consist of a verification that the annunicator panel is not lit if the voltage is in specification. Channel checks cannot be performed on the timers and are, therefore, listed as not applicable. The channel functional test will consist of a test of the annunciator circuits only.

The timers cannot be tested without actuating the diesels and shedding loads, therefore, these circuits are listed as not applicable.

Page 3/4 8-13 The minimum battery capacity has been increased to 82 percent to account for possible discharge during the Cive minute delay on the degraded voltage protection channel actuation. The new limit will ensure that the batteries can meet the two hour accident load requirement for all cases.

HJB:COH 5/28/82 l

Tennessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2 Degraded Voltage Relaying Licensing Subnittal Appendix C FSAR Omnges i

4 061273.04 .

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, , . . . _ -. _ . _ ~ . . _ _. - - _ _ _ , . , - . _

1 Replace pages 8.3-8 and 8.3-9 cf " Standby Diesel Generator Operation" with the following:

l l

061274.04

4 sun &v nl. cal cenerator coeraHna

' i he diesel generator system is shown on single line diagram, Figure 8.3-20.

W e sch aatic of the engine start and stop circuits is shown in Figure 8.3-21. Rarnote control of tha engine fram the main control rom is acceplished through interposing relays located in the diesel building.

n e schematic for this control is shown in figure 8.3-22. i i

n e 6.9-kV shutdown boards in each power train deriva power fra either of two circuits frm the 6.9-kV unit boards, or fram their respective stan&y

} power-source. During conditions where neither the nuclear unit nor 4

preferred (offsite) power. are available, each 6.9-kV shutdown board is energized fra a separate, independent dedicated stan&y diesel generatcr unit. See table 8.2-2 for ceplete description of board transfer schemes.

4 n e connection of the diesel generators to the 6.9-kV shutdown boards is 2

initiated by either the loss-of-voltage relays on the 6.9-kV bus or the degraded-voltage relays. h e lossrof-voltage relays are set to pickup at 70 percent of nminal whereas the degraded voltage relays are set to pickup 1

at 95 percent of nminal. A sustained voltage below these setpoints will j- initiate starting the diesel generators, tripping the normal or alternate feeder breaker, all 6.9;kV loads except the 480V shutdown board transformers, and the major 480V loads. Table 8.3-2 lists the loads that tre aut matically tripped. For a cmplete description of the voltage relay 2ogic, see the system description of section (page 8.3-4) . When the diesel

! generator set has reached rated speed and voltage (maximum of 10 seconds i

t frm initiation of automatic start signal), it is autmatically connected i

to the 6.9-kV shutdown board bus. %e return of voltage to the 6.9-kV

} shutdown board bus initiates logic which connects the required loads in the I proper sequence. Table 8.3-3 shows the order in which the losds are applied.

i We loss of voltage load shedding relays. remain in the circuit at all times. If the load shedding relays (170 percent) and time delay (5 4

seconds at 0 volta) setpoint is reached, the proper operation is: ,

i 1. To shed loads to prevent overloading the diesel generator.

2. Allow the diesel generator to recover to rated speed and voltage, i'

3. Reconnect the loads in the proper sequence.

I

~

Since the load shedding relays recognize loss of voltage, the atarting cf the largest dr'ven load will not cause actuation of the load-i shedding feature.

4 i

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As shown in Table 8.3- 3, 'there are two loading seqtt.nces. One, which is applied in the abser.ce of a

safety injection signa'. (SIS)," the non-accident condition," and the other, the " accident et ndition," applied when a safety injection signal ~i3' received orior to. or coincidont with a sustainad inaa of voltace on the 6.9-kV shutdom board. A safety injection signal received during the course of a nontccident ahutdown loading sequence will cause the; actions described bel w:

1. Ioads already sequentially connected which are not required for an accieene will be disconnected.

2. w aa already sequentially connected which are required for an accident will renain conreted.

3. Icads awa'. ting sequential loading that are not requir'ed for an accident will not be connected.

~

4. 'Ioads awaitira sequential loading that are required for an accident will have theit sequential timers reset to time zero fran which they will then be sequentially loaded.

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. . e Replace the bus transfer schme description for the 6.9-kV shutdown boards in Table 8.2.2 with the following:

061274.04

)

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.. Pon.asr cmwn14,n ngs Board /ain _B;tmal Alternate Standbv Remarks

(.,

15 6.9-kV Shut- 6.9-kV Unit 6.9-kV Unit Diesel Gen Autmatic transfer down Board 1A-A Board IB Board 1A lA-A to the alternate is initiated by 16 6.9-kV Shut- 6.9-kV Unit 6.9-kV Unit Diesel Gen undervoltage on the down Board 19-B Board 1C Board ID 1&-B normal feeder at 80% n minal voltage for four seconds. Transfer between normal and alternate is accomplished by closing alternate breaker at 30% nminal voltage if alternate supply voltage 95% ncnunal.

Ioss-of-bus voltage (* 70 percent) for 1.5 seconds starts the diesel generators and continued failure for an additional 3.5 seconds will trip incoming feeder breakers and most motor breakers. hten diesel 3enerator is up to rated speed and voltage, the energency breaker will close autmatically to connect the diesel to the

board, and loads will be applied as required by a sequential timer. Return to normal supply is manual only and is a fast transfer (16 cycles). MCR is annunciated on under voltage condition at 80% n minal. Transfer.

to the diesel generator for a sustained degraded undervoltage (UV) is initiated in 10 ,

seconds (if a SI has been initiated, or is

\

subsequently initiated) and 5 minutes for non-SI if below setpoint of 95% nominal. MCR annunciation occurs for UV of 95% ncminal and overvoltage of 105% n minal. The shutdown utility bus allows any 6.9-kV shutdown board to be connected to any other or all other 6.9-kV shutdown boards. All circuit breakers connected to this bus are normally open and disconnected. Use of the bus requires manual insertion and closing of two of the breakers.

i e

061257.05 o

e l

kPlace "Systen Operation" in section 8.3.1.1 with the following:

9 O

061274.04

4 To protect the Cass 1E buses fra a sustained degraded undervoltage, each of the two 6.9-kV Q ass 1E buses per unit will be provided with a set 1 of three instaneous solid-state undervoltage relays (ITE-type 27/59H) .

Sese relays will have a nminal setpoint of 6560Vi1/2 percent (95 percent of nominal). S e relays will be arranged in a two-out-of-three coincidence logic to initiate three time delay sequences. W e first sequence of 30 seconds will ride through normal system voltage transients before annunciating the undervoltage in the main control rom. W e second sequence of 10 seconds is short enough to allow safety-related equipoent to be powered within the time required by the safety analysis. At the end of 10 seconds if a SIS has been initiated, or is subsequently initiated, the shutdown board will transfer to its diesel generator. W e third time delay of five minutes is long enough to allow operator action but not allow damage to connected safety-related equipment. At the end of five minutes, the shutdown board will transfer to its diesel generator if the voltage has not returned to normal.

To protect the C ass 1E buses fra a sustained overvoltage, each of the two 6.9-kV G ass 1E buses per unit will be provided with a set of three inhtantaneous solid-state overvoltage relays (ITE-type 59H) . Sese relays wil). be arranged in a one-out-of-three ooindence logic which will annunciate in the control rom. H e relays will have a nominal voltage setpoint of 7260 volts i 1 percent (105 percent of nminal) . Se operator will take the action necessary to reduce the voltage.

W ere are no automatic transfers of board supplies between redundant power sources. All 480V shutdown boards and all motor control centers have alternate feeders to their respective board buses. Transfers between the normal and alternate feeder are manual. Some manual transfers of loads between power trains are used. Sese transfers are at the 480V level and involve nine loads which are tabulated in Table 8.3-10.

A means of manually interconnecting power sources at the 6.9-kV level is provided. his is provided by the shutdown utility bus, which on figure 8.1-2, allows any 6.9-kV shutdown board to be connected to any other or all i

other 6.9-kV shutdown boards. All circuit breakers connected to this bus are normally open and disconnected (racked out). Use of the bus requires manual insertion and closing of two of the breakers. We purpose of this utility bus is to increase the flexibility of the Standby Power Systs.

l A manual means of supplying power to the 480V auxiliary building cmmon

' board (which is not normally supplied power from the diesel generators during a condition where offsite power is lost) is provided. Provisions have been made to mamually ccrsect this board to the 480V shutdown boards 1B2 and 2B2. Wis is shown in figure 8.3-9. We purpose is to provide power to operate the ice condenser refrigeration units and glycol pumps during the unlikely condition of a loss of offsite power that exceeds 2-3 days. We two normal bus feeder breakers must be moved fra their normal cmpartments to the cmpartments which are connected to the 480V shutdown boards 1B2 and 2B2.

.~. _ __ _ -_ ___

syseam coeratinn '

he 6.9-kV shutdown boards in each power train derive power fra either of two circuits from the 6.9-kV unit boards, or fra their respective stan&y power source (diesel generator). %e feeders connecting each shutdown board with these three sources are termed the normal, alternate, and stan &y feeders. Se normal and alternate feeders can derive power from the nuclear unit, via separate unit station service transformers and separate 6.9-kV unit boards. % e normal and alternate feeders can also derive power frm the separate preferred source circuits, via separate windings (on either of two separate camon station service transformers) and separate 6.9-kV unit boards. During conditions where neither nuclear unit nor preferred (offsite) power is available, each 6.9-kV shutdown board is energized frem a separate stan &y diesel generator, via the standby feeder.

W e aligm ent of each unit's standby distribution syst e is determined by plant conditions, the sources selected to energize it, and the status of camponents within the distribution system.

A loss of voltage (f 80%) on a normal feeder to a 6.9-kV shutdown board is .<

detected by a Wt-of-three Jogic followed by a definite time delay of .

four seconds to initiate autmatic transfer to the alternate feeder, if the alternate feeder voltage is at least 95 percent of nominal. Se transfer "

is delayed until the bus voltage has decreased to 30 percent of nminal.

The return transfer to the normal feeder is initiated manually and is a high speed transfer, c mpleted in approximately six cycles or less.

A sustained (1.5 seconds at zero volts) loss of voltage (6 70 percent) on the 6.9-kV shutdown board starts the diesel generator and initiates (after an additional 3.5 seconds) logic that trips the normal or alternate feeder .

breaker, all 6900V loads (except the 480V shutdown board transformers), and the major 480V loads. Table 8.3-2 shows the loads that are autm.atically-stripped. Figures 8.318 and 8.3-19 show the load stripping schmatically.

When the diesel generator has reached rated speed and voltage, the -

generator will be autmatically connected to the 6.9-kV shutdown board l bus. (Refer to figure 8.3-20a.) his return of voltage to the 6.9-kV shutdown bus initiates logic which connects the required loads in sequence. Table 8.3-3 shows the sequence of applied loads. De standby (onsite) power system's autmatic sequencing logic is designed to automatically connect the required loads in proper sequence should the logic receive an accident signal prior to, concurrent with, or following a loss of all nuclear unit and preferred (offsite) power.

c-y. - -- - , - - . - - -

~

We following analyses evaluates voltages associated with different m conditions of unit operation and shutdown.

For normal operation of units 1 and 2, th,: main generator is used to supply power to the plant auxiliary power systen through the unit station service transformers. With the main generator at its minimum voltage of 22.8 kV, starting the largest motor on the 6.9-kV unit and shutdown board will not cause spurious tripping of the normal (see Figure B) .

If a safety injection (SI) shculd occur during nonnal operation of the unit, the reactor would be tripped and the turbine stop valves closed. If an electrical fault in the generator or switchyard is not present, the generator is not tripped, via the main transformer high-side breaker, for 30 seconds. During this time, approximately 4000 horsepower of SI motors are simultaneously started. The 6.9-kV shutdown board voltage will dip to approximately 6200 volts but will recover to 6640 volts after approximately four seconds, with the main generator voltage at its minimum of 22.8 kV (see Figure C) .

For the same condition, but with an electrical fault of the switchyard or main generator, the 6.9-kV unit boards are transferred (approximately six cycles) to the preferred offsite supply. With one of the two CSST's out of service, the starting of the SI actuated loads will cause the 6.9-kV shutdown boards to dip to approximately 6370 volts for approximately four seconds recovering to approximately 7000 volts, with the 161-kV grid at 162 kV (see Figure D) .

For the case of a two-unit full-load rejection, with one CSST out of service and the 161-kV grid at 162 kV, the steady-state 6.9-kV shutdown board voltages range frca 6585 to 6618 volts, which is adequate for starting the required medium- and lor voltage motors (see Figure E).

For all the cases listed above, the recovery voltages and times are within the time and voltage settings of the degraded undervoltage detection system and would not cause spurious trips of the normal or preferred supplies.

Ir.alysis of Thna Dolav Selected The second level of undervoltage relays operate if a 6900-volt shutdown 4

board bus voltage drops below the level required to successfully' start all the safety-related equipnent that would be required for the design basis accident. The relays will initiate three time delay sequences. The first sequence of 30 seconds will ride through normal systen transients before annunciating in the main control room. The second sequence of t o seconds is short enough to allow safety-related equipnent to be powered within the time required by the safety analysis. At the end of 10 seconds, if a safety injection has been initiated, or is subsequantly initiated, the shutdown board will transfer to its diesel generator.

The third time delay of five minutes is long enough to allow operator action to correct the undervoltage condition, but not allow damage to connected safety-related equipnent. At the end of the 5-minute delay, the i

~ ,

9 shutdown board will transfer to its diesel if voltage has not been corrected. Since the loss of voltage relays on normal feeder only are set at 80 percent of ncminal for four seconds, the band of voltages that a non-accident degraded voltage condition can exist is fran 80 to 95 percent of naninal for five minutes. At 80 percent of naninal the voltage at the terminals of running motors will not drop below 71 percent of motor rated voltage. NDR Class B r:ctors will not stall Also, out or be damaged above this during the five-M nute point for the time delay of five minutes.

time delay the 125V de vital battery boards could be powered by the batteries instead of the battery chargers. However, the vital batteries have sufficient capacity to meet this requirenent, as well as meet the original design requirenents as identified in section 8.3.2 cf the Sequoyah FSAR.

For a loss of voltage, both the selected time delays allow for the loss-of-voltage relays to initiate transfer to the alternate supply, if it is greater than 95 percent of nominal, before tripping and transferring to the diesels.

Aderrorof+0.5 percent for the timer / relays in the degraded voltage protection circuits has been considered in the design.

e

ML20069D819

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