ML17312B031

Proposed Tech Specs 3/4.8.1.1 Re A.C. Sources - Operating

ML17312B031
Person / Time
Site:	Palo Verde
Issue date:	11/06/1996
From:	ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:
Shared Package
ML17312B029	List: ML17312B031
References
NUDOCS 9611140062
Download: ML17312B031 (20)

Text

ENCLOSURE 2 REVISED TECHNICAL SPECIFICATION PAGES TO TECHNICAL SPECIFICATION 3/4.S.1.1 A.C. SOURCES - OPERATING 9'611140062 961106 PDR ADQCK 05000528 i P PDR

l 0

~

~ o

TR C POW R SYST HS HITING COND TION FOR OPERATION Continued

~CT OM (Continued)

.* 'With switchyard voltage less than 524 kV and with three startup transformers in service, restore OPERABILITY of one train of A.

ources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'it

1. estore OPERABILITY of the remaining EDG by startin loadi~g, a separating from offsite power within the next our; AND res re the remaining offsite circuit to OPERAB status within 72 ho AND within 6 days from the discovery f failure to meet the CO; OR

2. Restore OPE LITY of the remaining t in of A.C. sources by blocking fast b transfer within t next hour; OR

3. Be in at least HOT NDBY with'he next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the fo owin 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />.

g.* With switchyard voltage less 525 kV and with two startup transformers in service, re ore RABILITY of one train of A.C.

sources by blocking fast s transfe within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

1. Restore OPERABI Y of the remainin EDG by starting, loading, and separati from offsite power wit the next hour; AND restore th emaining offsite circuit to PERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> D within 6 days from the discov of failure to meet t LCO OR

2. R ore OPERABILITY of the remaining train of A. . sources by ocking fast bus transfer within the next hour; OR Be in at least HOT STANDBY within the next 6 hours and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

~ ~

~~Enter applicable conditions and requirements of TS LCO 3.8.1.1 ACTION a for the INOPERABLE offsite circuit.

PALO VERDE - UNIT 1 3/8 8-2a Amendment No. 102

T<<q V

<< ~

~

'

>><<<<

~

a

~

>>I

<< f C <> T ~ II

~ >>*-

f~ g ~ * <<>> I

( ~

f

~, T TO

~'

Insert A With switchyard voltage less than 524 kV, with three startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from offsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 524 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYof both trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 524 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

With switchyard voltage less than 525 kV, with two startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from offsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYof both trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBYwithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

1

~

p L

I

CTR CA R YTMS gE'PALACE AS S c4 rculeL voga a prakcfio RC T P T T 0 YS (Continued)

ACTIN requirements 3.8.1.1.f and 3.8.1.l.g prov de restrictions upon continued unit operation commensurate with degradatio of switchyard voltage and restoration of OPERABILITY of In an effort to minimize the risk to the health and safety to the public, ACTIONS 3.8.l.l.f and 3.8.1.1.g balance the risk of a forced shutdown against the risk of remaining at power with a switchyard vo'Itage in the lower portion of the expected range. The risk during ACTIONS 3.8.l.l.f and 3.8.1.1.g due to a switchyard voltage in the lower portion of the expected range and an independent accident is less than the risk associated with a normal shutdown including a reactor trip.

Conforaance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONS 3.8. 1.1.f and 3.8.l.l.g. At voltages below those identified, a unit trip resulting from an ESF signal, coincident with low switchyard voltages, will result in sequencing of ESF equipment. on preferred offsite power. The Class 1E degraded voltage relays will detect a sustained degraded voltage due to the fast bus transfer of non-Class lE loads from the auxiliary transformers to the startup tr ansformers. The relays will actuate to stri'p the ESF equipment and resequence it on the emergency diesel

,generator. This "double sequencing" causes an interruption in equipment credited with specific response time in the UFSAR Chapter 6 and'5 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified eat,ue prevents this effect as does the configurations authorized by ACTIONS 3.8.l.l.f and 3.8. l.l.g. The required voltage is higher when three units are operating on two startup transformers, as two secondary windings of the startup transformers must each supply ESF power to two units.

lREJE

~ ~ ~ ~ ~ NS 3 8

~ ~ ~ ~ ~ e designed o alance t a s of double sequencing (should no actions to mitigate be undertaken) due to switchyard voltage in the lower portion of the expected range coincident with an accident, which is unlikely, against the probability of natural circulation (should both trains of fast bus transfer be blocked) due to a unit trip coincident with switchyard voltage in the lower portion of the expected range, which is also unlikely but more probable. ACTIONS 3.8. l. l.f. 1 and 3.8. l.l.g.l provides offsite power to half of the non-class'E loads for forced circulation to respond to a normal plant trip, as well as EDG power and the second offsite power circuit to the two trains of ESF equipment to respond to any accident. ACTIONS 3.8. l.l.f.2 and 3.8.1. l.g.2 are '

Ss t a ow o on f bot tra s s bus tr sfer b c

~<el s '

~W'w* alt+~ 4~,~;;~

hA>>>>4 >g %<>>~I'LL 0m ) ~ qL, m i, ~)g~~,q' a p

~

gelu.aeR Xlh>>v4u AfAe85s3 A g g/oft a+~ ce 4~!,~~1 5V

~ ~>AA~

voB~c, AA!>>o Action ts Rstlgkeg w 4c.3h1R M4e ~ ~z me%>>bless A>>a cApA4(e a4 u>>4. 4 c, P4. Mss 3

buses.

Amendment No. 10

~ r Q~'Qg ~'

I r ~ ~ rP t~

~4 ~ r~ P 8

<<iaaf RJKl j 4$

~v ~

~...,a,,

V gg0~~gg q,,'qg+$",p,Q~ g(gt Qv '.L 'cY < b <4J"'<w~ j $ 01,. gc P'+6'(g, lb.'a 9A

~pl 'yer +Ctrl A *SieAL +9/J &Nay Ir . el jd LSy') al 4 r, ~,'~r gg 4>w<

Qp( )

'LS

~ ~

' W ~ I i'I~,l \g ~~,s

+1',Ar+," ~ aqqo]4yg I ~~"

Qk ' o o~C)9+i,~ i~ '+Pe ILES+~ y,',

~

>it,

~

~

q, w '3 'j%ta W g

~ ~

~

~ . ~W 'q,"~,f'>>~4 ~ g>>i(g~ +'jq '>) 4~~ p,P P i~~P4r, 9P <<4".I >> k)9~ikt~i.+ )

O~iwy('fd <%~.,</'t...:p's'".. 0'9z ij>f '~i;". w4't~f; ~it 4(qi ~r~Q'0'I Cg.'rr('.",~'v:p qg)(()

~

• c i

c;.n qs,

+-

(e

" ~ E+ <~ 4 '+'~ >3 ~w 6 IQ..s ~Qfg ~ s <5 DPi a,0) ~)go

ECTR CA POWER SYST MS HIT ING CONDITION FOR OPERATION Continued

~CT gN (Continued)

.* Mith switchyard voltage less than 518 kV and with three startup transformers in service, restore OPERABILITY of one trai~ of A.

ources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND eit I. Restore OPERABILITY of the remaining EDG by startin loadi~g, d separating from offsite power within the next our; AND re re the remaining offsite circuit to OPERAB status within 72 ho s AND within 6 days from the discover f failure to meet th LCO; OR

2. Restore OPE ILITY of the remaining in of A.C. sources by blocking fast s transfer within t next hour; OR

3. Be in at least HOT within the TANDBY wit 'he next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN llowin 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

g.* With switchyard voltage less n 525 kV and with two startup transformers in service, r tore PERABILITY of one train of A.C.

sources by blocking fast us trans within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

1. Restore OPERAB ITY of the remaini EDG by starting, loadiyg, and separati from offsite power wi in the next hour; AND restore t remaining offsite circuit OPERABLE status within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the disco ry of failure to meet e LCO; OR

2. store OPERABILITY of the remaining train of A. . sources by blocking fast bus transfer within the next hour;

3. Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> an 'n COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

) ELKS nter applicable conditions and requirements of TS LCO 3.8.1.1 ACTION a for the INOPERABLE offsite circuit.

qpliS~

PALO VERDE UNIT 2 3/4 8-2a Amendment No. 9o

'

~ r s ~

J 4

r H

~ f lao )

Opt (g I~

Insert B With switchyard voltage less than 518 kV, with three startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from oAsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 518 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYof both trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 518 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBYwithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

g. With switchyard voltage less than 525 kV, with two startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from oAsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYofboth trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBYwithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

~ l TR T S ASES C RC D ON W UT (Continued)

ACTION requirements 3.8. 1. l.f and 3.8.1.1.g prov de restrictions upon continued unit operation commensurate with degradatio of switchyard voltage and restoration 'of OPERABILITY of In an effort to minimize the risk to the health and safety to the public, ACTIONS 3.8.1.1.f and 3.8.1.1.g balance the risk of a forced shutdown against the risk of remaining at power with a switchyard voltage in the lower portion of the expected range. The risk during ACTIONS 3.8.l.l.f and 3.8.1.1.g due to a switchyard voltage in the lower portion of the expected range and an independent accident is less than the risk associated with a normal shutdown including a reactor trip.

Conformance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONS 3.8. l. l.f and 3.8.1.1.g. At voltages below those identified, a unit trip resulting from an ESF signal, coincident with low switchyard voltages, will result in sequencing of ESF equipment on preferred offsite power. The Class 1E degraded voltage relays will detect a sustained degraded voltage due to the fast bus transfer of non-Class 1E loads from the auxiliary transformers to the startup transformers. The relays will actuate to strip the ESF equipment and resequence it on the emergency diesel generator. This "double sequencing" causes an interruption in. equipment credited with specific response time in the UFSAR Chapter 6 and 15 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified value prevents this effect as does the configurations authorized by ACTIONS 3.8. 1. I.f and 3.8. 1. I.g. The required voltage is higher when three units are operating on two startup transformers, as two secondary windings of the startup transformers must each supply ESF power to two units.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ n ~ ~ ~ ~ ~ e designed o a ance e ro abl s y double sequencing (should no actions to mitigate be undertaken) due to switchyard voltage in the lower portion of the expected range coincident with an accident, which is unlikely, against the probability of natural circulation (should both trains of fast bus transfer be blocked) due to a unit trip coincident with switchyard voltage in the lower portion of the expected range, which is also unlikely but more probable. ACTIONS 3.8.1. l.f.l and 3.8.1.1.g.l provides offsite power to half of the non-class 1E loads for forced circulation to respond to a normal plant trip, as well as EDG power and the second offsite power circuit to the two trains of ESF equipment to respond to any accident. ACTIONS 3.8.1.1.f.2 and 3.8.l.l.g.2 are rov REVl~

to allow o era

~ 4esoe on Aek vo

~'eeg xP he<fees MAAg s f both 5 ee 4 trains of fast

'oa io 55 s transfer NAe1 logs Aee 88,6R

+pe <g~ a1 4e Jes13kej AHA a lAys (&14),4ea>ke J,co 's pd Ash Ao Adios t5 w

~

blocke .

4R. ccyge4'I ev'oi~u,oi k;e;. RP~LsW<51oaa hAs Aleee ~eRRht,Aok4eWRs +oeerl'Ad'oAfed, << tie Lc'o rs 1eef, p, AekieR oPsos]c4yAR<k voHAAeAe5 o.io Achov 15 >o,ieeh As We&4 ARe.

GA AMe oI At@kelotA oo4 vo "~~ 0455 2< V.5N Loses PALO V E UNIT B 3/4 8-3 Amen ent No. 90

l ,~ ~ <<mt P A ~

e graf

~! 1I I

~ r>> r ~

~

~

~ w P

- w = >>o~

~

jl g t'g.",pii4"8 .~54 p> 'w.",pj;,e pV.. ~~g,(jk~ gg.i.( @')l t$ ~~Ore'jJ"%J3i~"3 o

~g < g w 0~g$ )Q$w Qf/ 2i'l,~P~ $ Ptf (y9 aP,j Pt ) g<~1 e~ 31)f al a0< r9lQPv~+~>> ~J' ~~> +@0 9i+il." l

,vI9 c<cfS','L (g< 174'i j44B<'" ~"g gg Qc':co<A't" i>ask "..l")c~!<f'll >~q)~~ )~5: -". <<->s. 'PJ f iA

~ ~

,g~pg9 wv4'"(l~;~',f,; g'JWh pi'(/lr .i+ r'('4, vd.,)g>i- WAgi4>,; lAp 4" P@~lt) ~41 ~i4 9Pyk,5i, Ki." (9J'<28+5'm<

,$Qg pQ~f g <>

..'SPY) ~ .'i) .].)

2>>

")

(htia'e

~."' *:

<<~xi ALi)>.

~X

)SoW>~r0 g >O>K

.0'."9"lAJ>~4 t'-)]4)(pl'i('l" A,

.p p

T MR Y HS IHITING CONDITION FOR OPERATION Continued

~CT~O (Continued) f.* Mith switchyard voltage less than 518 kV and with three startup transformers in service, restore OPERABILITY of one trai~ of A.C.

sources by blocking fast bus transfer within I hour; AND either

1. Restore OPERABILITY of the remaining EDG by starting, adi~g, separating from offsite power within the next h  ; AND res re the remaining offsite circuit to OPERABLE tatus within 72 ho s AND within 6 days from the discovery failure to, meet the LCO; R

2. Restore OPE LITY of the remaining tr n of A.C. sources by blocking fast b transfer within th ext hour; OR

3. Be in at least HOT S NDBY with'he next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the fo wing hours.

g.* lith switchyard voltage less an 25 kV and with two startup transformers in service, re ore 0 BILITY of one train of A.C.

sources by blocking fast s transfer ithin I hour; AND'ither:

I. Restore OPERAB TY of the remaining G by starting, loadi~g, and separati from offsite power within he next hour; AND restore t remaining offsite circuit to 0 RABLE status within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discover the f failure to meet

OR

2. store OPERABILITY of the remaining train of A.C. s rces by blocking fast bus transfer within the next hour; OR

3. Be in at least HOT STANDBY within the next 6 hours and in D SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

II s Enter applicable conditions and requirements of TS LCO 3.8.1.1 ACTION a for INOPERABLE offsite circuit.

<< the PALO VERDE UNIT 3 3/4 8-2a Amendment No. 73

1 ~

p~ e aa

'a e a%

W ' a H

~'

.~ ~ ~

~ 'aa ~

Ih aa 4 aa+ a p ~ P

/ 4 ~

a

~ 'laaa

Insert C

f. With switchyard voltage less than 518 kV, with three startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from offsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 518 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYof both trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 518 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

With switchyard voltage less than'525 kV, with two startup transformers in service, and with circuit breakers NANS03B and NANS04B open:

Restore OPERABILITYof degraded voltage protection by blocking fast bus transfer for one train within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and start, load, and separate the opposite train's EDG from offsite power within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Restore OPERABILITYof both trains of degraded voltage protection by blocking fast bus transfer on both trains within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND restore switchyard voltage above 525 kV within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; OR Be in at least HOT STANDBYwithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

J P~v gL

CTR CA l

gEP4ACE Q mitibi vojk e peo4~'~

ASES

. SOUR S . RC S AN NS T POWER STRIB T S ST (Continued)

ACTION requirements 3.8. l. l.f and 3.8. 1. l.g pr ide restrictions upon continued unit operation commensurate with degrad ion of switchyard voltage and restoration of OPERABILITY of In an effort to minimize the risk to the health and safety to the public, ACTIONS 3.8.l.l.f and 3.8. 1. l.g balance the risk of a forced shutdown against the risk of remaining at power with a switchyard voltage in the lower portion of the expected range.

The risk during ACTIONS 3.8.1.1.f and 3.8.1.1.g due to a switchyard voltage in the lower portion of the expected range and an independent accident is less than the risk associated with a normal shutdown including a reactor trip.

Conformance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONS 3.8. 1.l.f and 3.8. l. 1.g. At voltages below those identified, a unit trip resulting from an ESF signal, coincident with low switchyard voltages, will result in sequencing of ESF equipment on preferred offsite power. The Class 1E degraded voltage relays will detect a sustained degraded voltage due to the fast bus transfer of non-Class 1E loads from the auxiliary transformers to the startup transformers. The relays will actuate to strip the ESF equipment and resequence it on the emergency diesel generator.

This "double sequencing" causes an interruption in equipment credited with specific response time in the UFSAR Chapter 6 and 15 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified value prevents this effect as does the configurations authorized by ACTIONS 3.8.1.1.f and 3.8. 1. 1.g. The required voltage is higher when three units are operating on two startup transformers, as two secondary windings of the startup transformers must each supply ESF power to two units. WczETK' t p

~ ~ ~ ~ ~

~ ~ ~

S .8....1 y of double sequencing

~ ~ ~ ~

an ..... e e >gne (should no actions to mitigate be o a undertaken) due to switchyard voltage in the lower portion of the expected range coincident with an accident, which is unlikely, against the probability of natural circulation (should both trains of fast bus transfer be blocked) due to a unit trip coincident with switchyard voltage in the lower portion of the expected range, which is also unlikely but more probable. ACTIONS 3.8.1.1.f.l and 3.8. 1. l.g. 1 provides offsite power to half of the non-class lE loads for forced circulation to respond to a normal plant trip, as well as EDG power and the second offsite power circuit to the two trains of ESF equipment to respond to any accident. ACTIONS ' 3.8.1.l.f.2 and 3.8.1.l.g.2 are rovide o

'o o of t ansfe bio ~

xt4e soii c ~ah vo e ie oio is eos 28.62seoiooh,+e eiieioek o@4nooi 4+o de j o@,e JiooMliii 0o 44iis Chilies) 4eii 4e. l.CD is kk ioo iioAoii )S ygiii~ei. ZP Laoolahes iSiioig ooovutRof, ioiie +eMVKs 4A e

ao.

loitA 'oIodoek,4c 8 a PIMPS ~oe doooko e.,

io+

ioie4

~~ k eLCo is iiie4 s M~ie h~s AR<Lle5s ops J,)~j,qof+ge, A~/ ioo sickie is esiio ae4'sos 4'e30Ks Ae >pht oii'ioiioiI

+laude vojh~e.d 'I4 Chss" & q./< >< ~iisos.

PALO VERDE - UNIT 3 B 3(4 8-3 Amendment No. 73

Set e .+a- I a% ~ e: ~ ~ ~ ~ I. ~

~ -'- W W Sa lap ae~ ~ el ~

h

'k

% ~ g 8? iV v"

~ 04++

5 A~

<~

l4

~~" i 4 ~>~4 ~

<>>.8>> 4ti' I'y P~+'<i I'l.fiV'a9$8~8+

g q

~

~

~

~

S 9p~5,<~'; pC pig~+;)q/g

~

9g9g <6A ',Q-"6 ~VF ".af ";~a,"~g/ @MAL '~;,yfl. 9h"~ ~Q ~k .4; ~;:g'j) "

. t*

" ~ ~ .I ..

g;,"p~

PI

=

..

~;~$

~

}

y g~ Q4 tot "r pi>s Aa..5.:.;.gpch".~ -w3! A', "<~ki'e~ ~5<<(c (s ..w Af>'w 7g,.P;gpss..4 - i ~ J 4 u ,

~

s'S~sa46ge ~~'*"0)'g << ~ i Ogpu +5)g, ( >)5g Q J>e.X~, s5/j Si'Afg g /l 4 7" >lr~ p C'4'i t$ 9rt~e>';,v qgtt':. 'i'll," F>>'~.>U'0'., 4s;y'.~) ~i~ <<.h ~-~~" ~f,~V,4 A<~,4.;g,.<g~;.g I 'e a$ i i i i,<<',g-,, +j' i~,>P~~ ~0< ,p,g&vGv'4V(lip>44 %+, 4 r r 4