ML20046C709

Proposed Tech Specs LCO 3.5.1 & Bases Re ECCS

ML20046C709
Person / Time
Site:	05200001
Issue date:	08/06/1993
From:	GENERAL ELECTRIC CO.
To:
Shared Package
ML20046C708	List: ML20046C707 ML20046C709
References
NUDOCS 9308110399
Download: ML20046C709 (22)

Text

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

,[ ,

ECCS-Operating B 3.5.1 1

83.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) f."" ^~^.:TR GE ;"10LAT:

0000= (mt) Y ,7G B 3.5.1 ECCS-Operating dire Mr f. A.n '

la4 d s a4 A ou+4rd e tha BASES

• * # # # # '" *I .

/

BACKGROUND The ECCS is designed, in co junction with the primary and secondary containment,- to 1 mit the release of radioactive materials to the environne t following a loss of coolant

( accident (LOCA). The ECCS = = ts; i..d:;:- e-' x ;.'. m i (8*AC+ " C' "7 Js o LA-+ i * ^

(findhi ad ; nyh to cool the core durin a LOCA. The  :

g ECCS network is; compos;e)d of the High orePressure W neoh r~ l (C..u a3 (AcJc) i ;, M CM System, Mand ) System, the & 8:::h:t the low pressura m "7 %jCe,e eth;; C;;# C;j mode of the -l Cort 9tooder ResidualHeatRemoval(RHR) System. The ECCS also consists gpq of the Automatic Depressurization System (ADS). The suppression pool provides the required source of water for t

pbo% +k ACIC the ECCS. Although no credit is taken in the safety Sy s t e ~- c' a d O t analyses for the condensate storage tank (CST). it is l capable of providino a source of water fora.; s?C^ Oj;ts.-

duo fifCf  ;

k J u b s r3 e< m s on receipt of an initiation signal. ECCS pumps automatically start; simultaneously the system aligns, and the pumps inject water, taken either from the CST or suppression pool, To a LLo w fr u.Q into the Reactor Coolant System (RCS) as RCS pressure is fn o e a t.c overcome by the discharge pressure of the ECCS pumps.

Cc4 Stem *+io^ ep Although the system is nit }~

~ w m uu ... ,..---- {-- ...p ted ADS action is delayed;

{ne 3 f ;stst,~ag p, t

~

alm;o;ee  ; n ; n ;d.d. The

-~ - r .

HP659 map u - ~. - -- v.u~.

discharge pressurer%'

st immediately exceeds that of the RCS, and the pum41u '

injecti coolant into rne nomy sparenr above the core.yIf gg,. N e the Dreak is small, HPGbwil' saints' n

• coolant ' nventory, as i

well as vessel level, while the RCS is still nressurized, k.

- If IP60failf, ,tNs9ack a up by AD5 in comb' nation with l r O n c.e. + h e stea m _!

L^C; x1 LPOCPLIn this e nt, the ADS timed sequence would he detuen Acrc hebrat be all ed to time out and pen the selected safety / relief

• h as. accetera+t/> valves (S/RVs), depressurir ng the RCS and allowing the LP i ind '.L. to overcome RCS pr sure and inject coolant into IN" C NN the vi ssel.- If the break is large, RCS pressure initially di 5dars t /)f * *2 4 r4 drops 1 rapidly, and the LG; ALLO L r -- coolLPFL the core.  !

D '* * * +K L ybf of Qu. gae s4 ppco,gy .; LT^^ .Wase JubTv%f) _

h Water from the break returns ;o the suppression pool where  !

t Ae. A c 5 a 4 laiect.: it is used again and again. Uater in t te suppression pool  !

l l

C '? LA 4 + la +o & is circulated through a heat t xchanger cooled by the 54endby Pe a cf c e p c4.r.s u r< hM x = (C"C))' System. Cepend'ng on the location and V t.2.r e. L ,q p y l size of the break,/ portions o1 the ECCS may be ineffective; 3 e/auste (m ) y;.  !

rum) 6%r'[p'-a.,

i e un a s. (4.ac+.r&

c..uns utta r (Acw cF pumps (continued) .;

i ABWRASTS B 3.5-1 4e. . O, 0;/C /;;

n t h

A

..........n ,

. . ECCS-Operating .

B 3.5.1 BASES i

t SACKGROUND however, the overall design is effective in cooling the core (continued) regardless of the size or location of the pipin Alth=;h n n;dit 4 td= f r. ;t; ;efe;, e... ,g.i. break.

ivr ui.

% :C !; t , it pe-fe- : : t;ile, f.a;;in ;; "*CS i;.: he;

--fe r d r d = ; -.y.Lilit,. huvunne sen, h wi", ni-' !n

'-;n t:ry r d :n. 05: ;ere, ;ii. ui. C ; i; still f p3 5 A.T f "~~; ; TG 0 = F ' ' ' " N 5 pr Q.. . &"

7 r

/j h i

All ECCS subsystems are designed to ensure that no single Of'r[rua,/) active component failure will prevent automatic initiation

• and successful operation of the minimum required ECCS 33gg g subsystems.  ;

- --y .

LPCS System (Ref.1) consists of a motor driven , a (

spra arger above the core, piping, and valve transfer i

'7 water fr he suppression pool to the sp . The LPCS gesc k L NL s ays r**

System is de d to provide coolin he reactor core i +c Ru s ucHe^ f e'^ when the reactor sure is 1 pon receipt of an the s unes33^ initiation signal, the uup is automatically started

/ceL. L e FL M2724*8 when AC power is a le. en the RPV pressure drops o a

• A c. h a v *- sufficiently flow to the begins. A full flow test ,

ole Atcat44 disc kar'34 line is ded to route water f to the suppression

^*N" 1'

• poo allow testing of the LPCS System t spraying '

g g + hat c o n ec.t er into the RPV. '

go 4 Le o)M3 Syst$m FL FL FL FL a k * ** l in the vesu L oaaut"# LPM is a independen operating mode of the RHR System. egka Y  ;

c. r e a o u.ts i k t t-h t There a three LP subsystems. Each LP subsystem  !

cor e skrou d . A PFL (Ref. 2) consists of a motor driven pump aptptng, and valves subsys+em A to trans er water from the suppression pool to thergsar. 8N dLstk oges +o eu (Each LP_ subsystem has y s y suction and discharge piping.

o.p fAe ma ta

- -r- - . - --. --------------.--------rL p..J u a-te r inJ' e chen A%d I"--d' l"b'"el ;4% De Nsubsystems are ,

designed to provide core cool ng at low RPV pressure. Ft.pon U '

J

1. ^ # ^ # *. "# rece'pt of an initiation signal, each LP90 pump is l SL3* ^ #'i

cooLart to th4 automatically n g ;, =g y 3.gstartetP(Ca .  ;;;;7

= indi;;d(,

_;;;  ;,ger ff ;- ,-. i; a.cong i N3

• L ^ ^* 'u 3

• *- Od3i4 04 afte K power is availableft When the RPV pressure drops ]  !

coreJArowd y,%

u iciently,LP4flowtotheRPVbegins. RHR System )

valves in the L flow path are automatically positioned to fkt-fr4844+er ensure the proper fjlow path for water from the suppression pool to inject in 6 the esce. A discharge test line is

' 5/ ke 34 r. provided to route water from and to the suppression pool to allow testing of each P pump without injecting water into the RPV.

dec+ ri C

• g ,

FL (continued)

, PrBWR7(STS B 3.5-2 1.1. o, siihii2

y. , , a c. v a. . . - . . -- _. --

RCIC System B 3.5.3 8 3.5 EMERGENCY C COOLING SYSTEMS (ECC AND REACTOR CORE ISOLATION COOLING (RCIC) TEM B 3.5.3 RCIC System .

BASES BACKGROUND The IC System is not part of t CC5; however, the RCIC Sy en is included with the ECCS se ion because of their s milar functions.

sw 9,-m .ns secs Suu Mon m F 7h' "CIC Sr5t'c i'Adf51gned to Operate either automatically or manually fo11owT65 reactor pressure vessel (RPV)

MOg +0 isolation accompanied by 'a loss of coolant flow from the feedwater system to provide adequate core cooling and f g 3,5" A control of RPV water level. Under these conditions, thego.p

"'4 Pr== Cn ;,..., (;;K3Pand RcIc systems perform c

siinilarfunctions. The RCIC System design requirements t

ensure that the criteria of Reference (a,re satisfied.

[The RCIC System (Ref! %) consists of a steam driven turbine pus) unit, piping, and valves to provide steam to the.

turnine, as well as piping and valves to transfer water from the suction source to the core via the feedwater system line. Suction piping is provided from the condensate storage tank (CST) and the suppression pool. Pump suction is normally aligned to the CST to mininfre injection of j q suppression poo water into the RPV. However, if the CST 4

water supply is low, or the suppression pool level is high, an automatic transfer to the suppression pool water source Mgl ensures a water supply for continuous operation of the RCIC System. The steam supply to the turbine is piped from main F

l steam line pstream of the inboard main steam line 3,6 ' 3 isolation valv gq The RCIC System is designed to vide core,co for a wide range of reactor pressures,M165bsig!t SQsig,,'

Upon receipt of an initiation signal, the RCI ine D' g accelerates to a s wcified speed. As the RCIC " low s increases, the turaine control valve is automatically NfCN adjusted to maintain design flow. Exhaust steam from the RCIC turbine is discharged to the suppression pool. A full flow test line is provided to route water from and to the to allow testing of the RCIC System during normal operation without injecting water into the RPV.

S HPf reSS le s f o o l-(continued)

~

-ihrRio iii 8 3.5-19  ::e. . O nohA/92

~

9 The E CS injection systems are arranged in three separate divisions each ccrprised of a high pressure and Icw pressure subsystem.

of the RCIC ECS Division 1 consists and L Fu-A. ECS Division 2 co.sists of on-consists of HPCF-C ECCS Division 3 LPFL-C.

6 s.s-u J

• ECCS-Operating

B 3.5.1 BASES i

rht McF sp rem is com/Ns*/ ef tm 24serar subsys te-a.

BACXGROUND EM THPChSye4em (Ref.h) consists of a single motor driven (continued) Aump. lyspay sparger above the core, and piping and valves 8"kl # A transfer water from the suction source to the sparger.

pr/

i Suction piping is provided from the CST and the suppression j pool. Pump suction is normally aligned to the CST source to hg minimize injection of suppression pool water into the RPV. i However, if the CST water supply is low or the suppression i pool level is high, an automatic transfer to the suppression  ;

l for continuous pool water operation of thesource ensgres HPCFSystem. a water The HPC supp$y', System is de ;

tp provide core cool ng over a wide range of RPV pressures t

1. 3 JcM vessel to suction '

Upon o to T2M '

Jricei psid to 1177 psi $, ion signal, thepum HPC7so re/e'.

automatically start /pt of an initiat(whenX powerndisvalves availablein the flow j gun pegin to open. Since the HPC ystem is designed to fr -

operate over the full range of expected'RPV pressures. HPC$

gl4c f r*

• L flow begins as soon as the necessary valves are open. A full flow test line is provided to route water from and to theCSTtoallowtesting;oftheHPC operation without n ;rwater intSystem th RPV. during nonnal Sid se AT M The ECCS pumps are provided with minimum flow bypass lines, f rom ou AIC which discharge to the suppression pool. The valves in these lines automatically open to prevent pump damage due to STS to 3.5-11 overheating when other discharge line valves are cloned or g (ATra.cke)) RPV pressure is greater than the LPAE;er-tPef pump d< scharge pressures follow' ng system initiation. To' ensure rapid delivery of water to the RPY and to minimize water hammer effects, the ECCS discharge line " keep fill" systems are  ;

designed to maintain all pump di charge lines filled with -

water. f gc, g The ADS (Ref, k consists of 8 of the [S/RVs .It is

{

designed to provide depress izat mary system during a small break LOCA if NPCI'yn fail / orof the p unable to '

maintain required water level in the RPV. ADS operation 1 8 7hv e +5 eun reduces the RPV pressure to within the operatingL. pressure i

/ggj range of the low pressure ECCS subsystems (LPCF... UQ, '

"C " "" '# N so that these subsystems can provide core cooling. Each ADS i valve is supplied with pn,eytic power frong g,

. .y'vi.v. ,

. - - _..............m-_...... .... ... ..... m . '

l.ocated in the drywell, or Fr- th e a+mos/ Ae rec '

contreL s y414. (Mc.s p u er fr o m n e a cc u) +4 w (La e ec.

+ s f-L e.t yisuWhen /r1&N+tc M ade).

L rkx A cs o tss .syp.t ez %< d+rq t^ (a + frasw*) .

11Rc4SSAf1 YO O SSV et Y hl US " C LU ^' " * ,

i N fh i^ C kA II'd [*f "#I IA W # 0 ^ Y # #' "# *

(continued)

ABWRA STS B 3.5-3 I 1

I

ECCS-OperaMng B 3 5.1-

, i l

l BASES (continued)

S .

3]3 **)

APPLICABLE The ECCS perfomanc is evaluated for the entire spe,ct of T l SAFETY ANALYSES break sizes for a stulated LOCA. The accidents for yhich  !

ECCS operation is quired are presented in References +t-4, ,

and+. The requ ed analyses and assumptions are defined in  ;

10 CFR 50 (Ref. ), and the results of these analyses are described in Reference P $

This LCO helps to ensure that the following acceptance 2

(' A M i+io^c t criteria for the ECCS, established by 10 CFR 50.46 qRef. M), will be met following a LOCA assuming the worst fyac. Hod d +Lt ue< case single active component failure in the ECCS: goy 'c rs

" ^1 3 by ff'Vidi^j A+ r4 at a. kh M det GMg WWm h Wh

b. Maximum cladding oxidation is s 0.17 times the total '

M *MP cocLant to cladding thickness before oxidation; .

the. nu cLee va.se.L erad to 6e co^ c. Maximum hydrogen generation from zirconium water

/4d e pe^d ert A C. reaction is s 0.0;, times the hypothetical amount that -

sou r c. e. d u rr ^3 would be generated if all of the metal in the cladding

'S+a+ t ea bLM K od- surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react;

d. The core is maintained in a coolable geometry; and

e. i ivistor 3. (HPCr ~6 cM Adequate long tem cooling capability is maintained./

limiting single failums are discussed in Reference Yt.

and LPFL -G) or .

Division 3 ( pc.r c 1 ", N , 5 h !0CA y ag u n g ECCS sub pstems in, '

onJ L/FL-c) [Nf[due af5ur[h 5ts as5Ni[tbh dibef hnbtor i k .L5 ? M th! ,.. ".et5?""___f*"_"."_n 5 , W

. . . _ _ . . _ . . One

),og,ger,fa.J;eselda.

.pmu o LAboot for events skattT ADS requiring AD5valve failure operation 7The is analyzed remain' ng OPERABLE as a limiting :'

a ^a .m ECCSsubsystemsprovidethecapabiiitytoadequatelycoo 3enecutor,J g 3 3 . e.ta +.< mobe d"I'^ the core and prevent excessive fuel damage. A '

E c c s ini e c +l 0^ '".M T n t** W5ggr -

he ECCS satisfy Criterion 3 of the NRC Policy Statement. 3

'3 la more rkdudivi ut4tg83'^L: P Lurt, LCO Each ECCS injection /ssray subsystem and eight ADS valves are required to be OPERAB.E. The ECCS injection / spray subsystems are defined as the three LPCI subsystems, the  ;

LPCS System, and the HPCS System. The low pressure ECCS  :

(continued) 8BWR75STS B 3.5-4 Rev. O, 09/28/92  !

i

6 N' v i. n u v b rM VC79 v wSJVv 4 - i e w Lv I

In order to provide increased rargin to IICS acceptance criteria (i.e.,10 CFR 50.46), the ICCS was designed to the more stringent goal of no core unceverr for any gestulated IEA or transient event, even given the nest limiting single failure. This design philosophy resulted in substantially inproved ECCS perforrance such that, when analyzed consistent with typical licensing basis methodologies (i.e.,

assuming only the traditional limiting single failure), there was considerable cargin relative to exirlpngregulatoryreqairements. The ragnitude of such margin suggested that the IrCS would still be able to perfom its intended safety function, even under various situations with some equignent irdtially out of service or unavailable due to nultiple postulated failures. Therefore, further IrCS aralyses were perforred (see Reference w in an attecpt to E identify the mini um amount of IrCS eqaignent that must operate such that the plant could still meet the 10 CFR 50.46 acceptance criteria listed above.

Analyses were performed for a set of identified liniting scerarios, assuming the unavailability (or failure) of multiple m subsystems, and using the same calculational methods as were used for the traditio al design basis analyses. The results of these analyses demonstrated that " success" (i.e., no violation of the ateve stated 50.46 licits) was achieved under various postulated accident scerarios provided at least one noter driven ECCS injection subsystem was capable of successfully injecting water into the R W. For any such scenarios also requiring depressurization, " success" was achieved with the actuation of at least five SR/Vs in the ADS mode (in conjunction with successful vessel injection from the one reqaired Ircs subsystem) . Thus, it was confimed that the A!WR EICS is able to perform its intended safety function (in accordance with the applicable regulatory reqaireents), even for postulated events involving limiting single failures that right occur with less than the full cocpliment of IrCS subsystems initially available.

6 3. 5 -%

~. v n .._ ~ .- . -.-. . .mvv ..n w --

ECCS-Operating B 3.5.1 BASES ,

,O' suk i LCO injectionZ3pMy subsystems are defined as the CMS 3 kstem (continued) and the three LP05 subsystems.

trL rearsurf. +h( i pkWL A b e. re duc.el With less than the required number of ECCS subsystems  !

and s ud Limi+s OPERABLE during a limiting design basis LOCA concurrent with i the worst case s< nol ailure, the limits specified in r

~[ 10 CFR 50.46 (Ref. D y could potentially be exceeded. gTil ,4 ,'

r ar( smef to L ECCS single rat ture subsystempave4-4hecefereir4PEM9 criterion required by 10 CFR 50.46 (Ref. '

v b e e,n.p+ 1 S L L Y he ECCS is supported by other systems that provide i avpLdLt sA Yk t automaticECCSinitiationsignals(LC03.3.5.1,' Emergency CoWr4heosiv4 Core Cooling System (ECCS) Instrumentation'),ueryice water 5a+ of a^*I3'I ECCS equipment (LC0 3.7.1, " C W ^

.

:._^. "^g _ i pec-9ermed to cool rooms FJ+

Seuce tie-q'"' }M dntf LC0 ..,

containing(!5:[ g,;,; ;;.7Mt 3 7 2""'  !

-d cqgy 3 {'RC;) R ;M; St:r !,;t.. M,5 Fr;;;; : C;n 5;n3 f,) . electrical power =na

~

r h u s a L.L. cccJ LCO 3.8.1, 'AC Sources-Operating', ) and LCO 3.8.4, 'DC uts-S Sg 'y yd Sources-Operating') . gQ gco 3,7,37 fj u utAcwq A LPN subsystem may be considered OPERAstr. during alignment  ;

(

f Reac ter hidiA3

. and operation for decay heat removal when below the actual RHR cut in permissive pressure in MODE 3, if capable of FL t

Coo Ling pa+er being manually realigned (remote or local) to the LP06de

, ( Acu) sys tre; and not otherwise inoperable. At these low pressures and

' Reacter Servict decay heat levels, a reduced complement of ECCS subsystems 4 can provide the required core cooling, thereby allowing  !

Uand d h k.AriMm +Sy(stro u eration of an RHR shutdown cooling loop when necessary.  !

t4 T Si4 C H M) -D Perm te S.5 65)cm*$ (30 Pala)

, APPLICABILITY All ECCS subsystems ar required to be OPERABLE during MODES 1, 2, and 3 who there is considerable energy in the

(%n MODES a e^/

reactor core and cor cooling would be required to prevent 3, + k e A C 5 c bate" fuel damage in the ent of a break in the primary system '

s nst equirdd h piping a In MODES and 3, the ADS function is not required Ac ops 4 Aas.e u kt^ when pressure is s .C0 ,,;it because the low pressure ECCS

pessuet is * /e,5 subsystems (LPOI,4Pei) are capable of providing flow into i the RPV below t1is pressure. ECCS requirements for MODES 4 K 3 /cd5(isoPsta) and 5 are spec 1fied in LC0 3.5.2, 'ECCS-Shutdown.'

p3 c., e n e r e c c .s ,

FL WWW W.?.W vena}  :

ACTIONS L.1 m o + e r cl e tec o (i.e.> HPcfg or LPFL)  ;

e  :

If any one (1._ ,. ..... . ECCS hj;;th$. ;; subsystem is  ;

inoperable, the inoperable subsystem must be restored to (continued)

ABWRNSTS B 3.5-5 ':2 v . O, 0;/2?I.92 s

ECCS-Operating B 3.5.1 BASES I ACTIONS Lj. (continued) g gore. th"^ -

OPERABLE status within days. In thi Condition, the remaining OPERABLE subsystems provide' adequate core cooling during a LOCA. However, overal l ECCS reliability is reduce

• and beoevee a single failure 44Mmefof the remaining OPERABLE ,

o subsystems concurrent with a LOCA pagrresult in M ECCS P e r ic>rm a c.e w .. w . + -- - z - >-22 ..o-s. z..- ->-- %y and reJv.c4J N In a rf in s -co f("-f.12 id 5) th:t :::15'Eitid1 =t-d th: ' ::t 55't$$$[5I:"Nii$biI5{((5$@

- SCCS rt:'i dilit,-ty toc FA 5 0,% accytom . N i ; ! ii th9t C N " R f " to f i _o," E '~~^ 2 -f ," 1 9 0' c ri +c ric . N _ " ' _ * * ' ' ! P 2 , , ! "' ' Y * " ' M "' ' - -- _' .

j- ; ;7 ; n

=

tg'=vs = m 8==i y y _v,5 y a 5u n..........

i-

_-g g 3 g e _

t _g,v....,.........

y v, y 3 -..p . g . 7. ..'.

ZASEAT 7 -

i M and B.2 If th PCS System is inoperable, and the RCIC Syst is immediat verified to be OPERABLE (when RCIC is quired to be OPE ),theHPCSSystemmustberestor to OPERABLE stat within 14 days. In this Con ion, adecuate f g Lu-R core cooling is ured by the OPERABILIT and diverse low pre ure ECCS injection ray subsystems in f the reduncant p i f- k conjunction with the . Also, the IC System will l

automatically provide na p water most reactor operating p tSE M pressures. Immediate veri ti of RCIC OPERA 81LITY is therefore required when HPCS ino>erable and RCIC is Kl required to be OPERABLE. s .>e perfomed by an administrative check, by asining gs or other information to detemine if RCIC i out of servi for maintenance or other reasons. It i not necessary to rfom the Surveillances noe to demonstrate the RABILITY of the RCIC Systes. H< ver, if the OPERABILITY o the RCIC System cannot be i ately verified and RCIC is re fred to be OPERABLE, C dition D aust be famediately ente . If a single a ve component fails concurrent with a d ign basis LOCA, re is a potential, depending on the specif fail e, that the minimum required ECCS equipment wil ot be vailable. A 14 day Completion Time is based on the sults of a reliability study (Ref.12) and has been fou d to be acceptable through operating experience.

(continued)

$BWR/6STS B 3.5-6 h.. O, 00/25/92 J

l

m, u ys u . v-m v a m. ni ._s e v .cuvv. ,,iums

.l i

l (At ,

i Nonetheless, even given the rse case single failure concurrent with a W CA initi ted frczn this Condition, there will always be at 1 t one ECS subsystem -

available to inject water 4 .to the RW. Additional '

analyses of limiting desi basis scerarios demonstrate that in su d es 10 CFR 50.46 acceptance criteria will still be me . Furchemore, results of '

PRA senshtivity studies performed (see Reference [ f show that this situation is acceptable from an overall plant risk pe. v ive. 'Ite 30 day Conpletion Time is

[ thus based on theyoverall redundarry provided by the

. ECS ard in crent med ability to perform its intended safety function, hile assuring a return to full ECS 1 capability in a reasorable time so as to not r significantly . ct overall E CS reliability. <

s I

gog p ro b li t'/ O k i

oca ,cmrecns a uN^3 .

G is ptrt00 9^b N ,

1 L

I i

O 3.5"$A \

\

l l

-m... , , r.

, q d(,

L1 -

If the RCIC System is inoperable during MODE 1, or MODES 2 or 3 with reactor steam dome pressure > 10.5 Kg/cm g (150 psig), it must be restored to OPERABLE status within 30 days. In this Condition, loss of the RCIC System will not affect the overall plant capability to provide makeup inventory at high RPV pressure since the two HPCF subsystems would still be available to provide makeup to the reactor during a loss of colant accident (LOCA) in which the RPV remained at high pressure. However, for transients and certain abnormal events with no LOCA, RCIC (as opposed to HPCF) is the preferred source of makeup coolant because its relatively small capacity and automatic flow control capability allows for easier control of RPV water level. Furthermore, with its steam driven turbine, the RCIC System provides the only source of reactor coolant make-up during a complete loss of AC power event. Therefore, only a limited time is allowed to restore the inoperable RCIC to OPERABLE status.

The 30 day Completion Time is based on the low probability of a LOCA occurring during this period and the overall redundancy provided by the ECCS and its continued ability to perform its intended safety function, while assuring a return to full ECCS capability in a reasonable time so as to not significantly impact overall ECCS reliability.

Additionally, a 14 day Completion Time for RCIC has been found to be acceptable through operating experience.

ECCS-Operating

- B 3.5.1 BASES 1

ACTIONS M . C.2. and C.3 . l (continued) l With two S injection subsystems inoperable or o -

injection an e ECCS spray subsystem inoper , at least  !

06pkAC one ECCS inject spray subsystem must stored to '

11 OPERABLE status wi 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. It s Condition, the Wt+g . i remaining OPERABLE subs s te adequate core cooling  !

during a LOCA. However, o ECCS reliability is reduced t f M S ggTJ in th's Condition bec a sin failure in one of the

%) i remaining 0PERAB LOCA may resul systems concu the ECCS not being nt with a design basis to erform its i

i I43 f intended s y function. Since the ECCS i ability is  :

reduce ative to Condition A, a more rest tve l C tion Time is imposed. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Complet' Time is  !

k sed on a reliability study, as provided in Referen 12. j

6 @

] i.1 and d.2 c,,D 'i g

i If any Required tio nd associated Completion Time of  :

Condition A, B, or are not met, the plant must be brought to a MODE in which the LCD does not apply. To achieve this L I s.s u r H .;

status, the plant must be brought to at least MODE 3 within i

froA m 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and'to MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times am reasonable, based on operating -

gU/t T63.5- /

• p) p experience, to reach the required plant conditions from full i power conditions in an orderly manner and without  ;

challenging plant systems.

$ i

',, 4 r N H, b u t t wuz 8yu.o eu%s in e 6 U4 .c e a i

des c a fThe LCO requires el nt m valves to be OPutABLE to provide .

.' buu the ADS function. ference 25 conta' ns tie resuiu oT og 5 analysis that evaluated ibs effect.of one ADS valve being '

out of serviceJ Per thOnalystt*, operation of only se ENoveoeq +he rmuT'rAos valves will provide the required depressurization._ y@N<

'I04 ^^^ 9 8#' However, overall reliability of the ADS is reduced %e.;; .

are 6 uJd by g a p ; r ,;; a ; 2 , e,; gwg g w,,, ;an 7;;e; 1,  ;

aJJi+ro^aL o^a'#" reduction in depressurization capability. Therefore ,.3o of mort LfM+I^3 j operation is only allowed for a limited time. The W day 1 sin g La. bRuM 5 c. < A A d o s y M c.L i foQtionTigg C

..., ...., M . 2,

-- .- ....- w. r-.--

lf fasSAT?  :

CADS Va Lue s t sar A* E* "^'b.

(continued)  ;

f

/tBWR/1kSTS B 3.5-7 Rev. O,09/28/92  !

t

--- . - - - - - - - - - - - - - _ _ - _ _ - - - - - - - - - - - - - - ,-- a . - - - *

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

, 3 l

C.1 and D.1 With one motor driven high pressure ECCS subsystem (HPCF) and one low pressure ECCS subsystem (LPFL) inoperable or any two low pressure ECCS subsystems inoperable, at least one ECCS subsystem must be restored to OPERABLE status within 30 days. However, with two high pressure ECCS subsystems inoperable, at least one inoperable high pressure ECCS subsystem must be restored to OPERABLE status within 14 days. In these Conditions, the remaining OPERABLE subsystems provide adequate core cooling during a LOCA. However, overall ECCS reliability is reduced and a single failure impacting one or more of the remaining OPERABLE subsystems concurrent with a LOCA would result in degraded ECCS performance and reduced margins to 10CFR50.46 acceptance criteria. Nonetheless, even given the worse case single failure concurrent with a LOCA initiated from these Conditions, there will always be i

at least one ECCS subsystem available to inject water into the RPV. Additional analyses of limiting design basis scenarios demonstrate that in such ca623 10 CFR 50.46 acceptance criteria will still be met (Ref. 8).

Furthermore, results of PRA sensitivity studies performed (see Reference 9) show that this situation is acceptable from an overall plant risk perspective.

The 30 day Completion Time for Required Action C.1 is thus based on the low probability of a LOCA occurring during this period and the overall redundancy provided by the ECCS and its continued ability to perform its intended safety function, while assuring a return to full ECCS capability in a reasonable time so as to not significantly impact overall ECCS reliability.

Additionally, the 30 day Completion Time is consistent with the allowable outage time for a single diesel generator which would affect the operability of a single ECCS division (i.e., one HPCF and one LPFL).

The 14 day Completion Time for Required Action D.1 is more restrictive because a single failure of the remaining high pressure ECCS subsystem may, during a LOCA, require an unwanted actuation of the ADS to reach the operating conditions of the low pressure ECCS subsystems.

P

jN ,

E.1 and F.1 With any three ECCS subsystems (except for the three high pressure ECCS subsystems) inoperable, at least one ECCS subsystem must be restored to OPERABLE status within 7 days. With any three high pressure ECCS subsystems inoperable, at least one high pressure ECCS -

subsystem must be restored to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. In these Conditions, the remaining OPERABLE subsystems provide adequate core cooling during a LOCA.

However, overall ECCS reliability is reduced because a single failure in one of the remaining OPERABLE subsystems concurrent with a LOCA initiated from these Conditions would result in degraded ECCS performance and reduced margins to 10 CFR 50.46 acceptance criteria. Nonetheless, even given the worse case single '

failure concurrent with a LOCA initiated from these conditions, there will always be at least one ECCS

subsystem available to inject water into the RPV.

Additional analyses of limiting design basis scenarios demonstrate that in such cases 10 CFR 50.46 acceptance criteria will still be met (Ref. 8).

Furthermore, results of PRA sensitivity studies performed (see Reference 9) show that this situation is acceptable from an overall plant risk perspective.

Since the ECCS availability is reduced relative to Conditions C or D, a more restrictive Completion Time is imposed. The 7 day Completion Time for Required Action E.1 is based on the low probability of a LOCA occurring during this period and the overall redundancy  ;

provided by the ECCS and its continued ability to perform the intended safety function while assuring a return towards full ECCS capability in a reasonable time so as to not significantly impact overall ECCS reliability.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time for Required Action F.1 is more restrictive because a LOCA may necessitate an unwanted actuation of the ADS to reach the operating conditions of the low pressure ECCS subsystems. l However, any one low pressure ECCS subsystem is capable <

of maintaining core coolant during a LOCA for the spectrum of break sizes. ,

)

i 1

uvw v m . v u c, mv mv a , , 2 w w -

, l

......is based on the low probability of a LOCA occurring during this period and the overall redundancy and capacity of the ADS System and its continued ability to perform its intended safety function, while assuring a return towards full ADS capability in a reasonable time so as to not significantly impact overall ADS or ECCS reliability. Furthermore, this condition has been modified by a NOTE that allows concurrent existence with Conditions A, B, C, D, E or F. Concurrent existence is justified by the additional ECCS analyses that were performed (Ref. 8) and greatly simplifies the necessary Required Actions.

.~. . ... .

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

' ECCS~0peraging '

, B 305.1 9

BASES  !

ACTIONS T J and F.2 -

(continued)

If any e low pressure ECCS injection / spray subs is '

inoperable addition to one inoperable ADS e, adequate core cooling ensured by the OPERABILIT HPCS and the i remaining low p ure ECCS injection ay subsystems. '

However, the overal CCS reliabi is reduced because a single active componen', ilu oncurrent with a design-

• basis LOCA could result i e minimum required ECCS equipment not being av ble. ince both a high pressure '

(ADS) and low pres subsystem inoperable, a more restrictive C ion Time of 72 ho is required to restore eith the low pressure ECCS in on/ spray subsyste toe ADS valve to OPERABLE statu This ,

Compi on Tise is based on a reliability study ef.12) i an as been fcund to be acceptable through operat ng perienc.

3 3 3

k.1andt.2 I. i5 fo u.c  !

If af, Required Action and associated Completion Time of

• Condition etir not met or if or more ADS valves are inoserable, the plant must be brought to a condition in which t1e LCD does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and l reactor steam done pressure reduced to ZC pi; within t 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times re reasonable, based on operating experience, to reach he recuired plant conditions from full power conditions i an orcerly manner ,

/6 0 W to and without challenging plant systems. l 3,s ge /ce*S

(> r e V i * *g'5 (.50,ssts)  ;

.Nd na c,n y be m When r M4h ECCS subsystems are inoperable, as stated in Condition H, the plant is in a condition outside of the ,

! accident analyses. Therefore, LCO 3.0.3 must be entered immediately.

SURVEILLANCE SR 3.5.1.1 REQUIREMENTS The flow path piping has the potential to develop voids and pockets of entrained air. Maintaining the pump discharge (continued)

PIBWR?$STS B 3.5-8 6. O, 00/?o' I

l 1

a, e, y -m o. - anc- . < owr c mg ----

ECCS-Operating-B 3.5.1 '

BASES SURVEILLANCE 5R 3.5.1.1 .

REQUIREMENTS (continued f# [ g$CJf g -

linesoftheHPCIIystem,p85 System,andLPMsubsystems  :

full of water ensures that the systems will perforu  ;

properly, injecting their full capacity into the RCS upon ,

demand. This will also  ;

ECCS initiation signal. prevent a water hammer following an One acceptable method of ensuring i the lines are full is to vent at the high points. The -

31 day Frequency is based on operating experience, on the procedural controls governing system operation, and on the gradual nature of vo' d buildup in the ECCS piping.  ;

SR 3.5.1.2 j

' verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides -

assurance that the proper flow paths will exist for ECCS operation. This SR does not apply to valves that are  :

locked, sealed or otherwise secured in position since these valves were ver,ified to be in the correct position prior to or securing. - A valve that receives an locking, sealingl is allowed to be in a nonaccident initiation signa p provided the. valve will automatically reposition in the ,

proper stroke time. This SR does not require any testing or valve manipulation; rather, it involves verification that  ;

those valves potentially capable of being mispositioned are '

in the correct position. This SR does not apply to valves t that cannot be inadvertently afsaligned,_ such as check valves. ,

The 31 day Frequency of this SR was derived fros,the Inservice Testing Program requirements for perfoming valve testing at least once every g2 days. The Frequency of  :

31 days is further justified because the valves are operated under procedural control and because fa> roper valve l alignment would only affect a single suasystem. This Frequency has been shown to be acceptable through operating experience. ,

FL This SR is modified by a Note that allows a LPK subsystem t to be considered OPERA 8LE during alignment and operation for i decay heat removal with reactor steam done pressure less  :

than the RHR cut in pemissive pressure in MODE 3, if capable of being manually realigned (remote or local) to the LP mode and not otherwise inoperable. This allows '

FL (continued)

BWR/6 STS B 3.5-9 Rev. O, 09/28/92 I

- . n.. . n w. m. - .n . - . n - -w - - - -

s

+

t ECCS-Opera 2ing ,

B 3.5.1  :

BASES '

SURVEILLANCE SR 3.5.1.2 (continued)

REQUIREMENTS  !

t operation in the RHR shutdown cooling mode during MODE 3 f f necessary. l l

SR 3.5.1.3 p,3 K$[c. d (NI @n btro ys ,c,gWu V cation every 31 days that ADS b r,ni.;r pressure is i prye A - t 02: ;;i; assures adequa13 44c pressure for reliable ADS operat'on. The accumulator on each ADS valve provides -

pneumatic pressure for valve actuation. The designed i pneumatic supply pressure requirements for the accumulator  !

o n e, are such that. following a failure of the pneumatic supply (orc.tga+(o45

@in vd** to the accumulator. at least W valve actuation / can occur -10 l

cu o cc u r w i+L with the drywell at JUtust design pressure *(Ref. !Q. "he i de dryw nt g ECCS safety analysis assumes on y one actuation to achieve

[

go3p w, c, j the depressurization required for operation of the low i

(p33, j pressure ECCS.

s provided by This minimum the't.% D;;;r n.required

Air

gressure off;O] ;;iii-

? P" _ . The p u s rggSg pp,33we< 31dayFrequencytakesintoconsideration;;a;d rative ditr*j 8^ b 5 and alams for low pressurh( A C, sa)

L y [ ] control over P *+ operation c- ofp the I SR 3.5.1.4 , sit 3.5.1 6 M S S R 3.S l. L  ;

The performance requirements of the ECCS pumps a Oft determinedthroughapplicationofthe10CFR5p pendix K, 6 Nteria (Ref.1). TMt" periodic Surveillaner perfomed (in accordance alth the ASME Code,Section XI, re '

for the ECCS pumps) to verify that the ECCS pumps'quirements will  :

develop the flow rates required by the respective analyses. .

The ECCS pump flow rates ensure that adequate core cooling  :

bT h # C J C. / W A is provided to satisfy the acceptance criteria of

%cp rote 5 AL30 10CFR50.46(Ref. )

80 3 "M 5 Y5'+8

{ The pump flow rat s are verified against a system head that M +%^C#f'" # "9, e is equivalent to the RPV pressure expected during a LOCA. ,

c.c o ' ^ d i ^ @ ^ # * # Y The total system pump outlet pressure is adequate to du N^3 ff* 55ur't*j iovercome the elevation i.ead pressure between the pump con ,$ / + / e a S wi+k suction and the vessel discharge, the piping friction  !

Iosses, and RPV pressure present during LOCAs. These values tat A/V / Set td. may be'e estabitshed r " ' c S during

= ' . rp=re-operational testing.

the -A 92 Jei i e ny =:; h t ee d er.c; .ith MrMr Trt ^ "reF= r;i; ;t;.

s esw S *r re,m cu Alb --* 1 s rs / M.5 -M .

(continued) ]

(A tt a t Wj kBWRhSTS B 3.5-10 6. O,C;/0/M 1

. RCIC System B 3.5.3 BASES SURVEILLANCE REQUIREMENTS

,5"  ?.5.? 2 = ' u ^ 5e.c .

/4 J(

(continued) [The " :0 ;; p f 6 . ni; cp[ure th:t +[~ -- -

I .naavi u vien h er,tcr .arir.; pre f2H n d c e ditier.s' w ".a'-

1 th: "' S:!;ted. The ow tests f the RCIC System are performed at two diff ent pressur ranges such that system capability to provi rated flow 's tested both at the higher and lower o erating range of the system. Since the required reactor team done pre ure must be available to l

f- perfom SR 3.5. . and SR 3.5. . , sufficient time is allowed after adequate pressure is achieved to perform these SRs. Reactor startup is allowed prior to performing the low pressure Surveillance because the reactor pressure is low and the time to satisfactorily perform the Surveillance is y 0 V 4 -FO short. The reactor pressure is allowed to be increased to 5'l noma 1 operating pressure since it is assumed that the low f6b pressure test has been satisfactorily completed and there is no indication or reason to believe that RCIC is inoperable.

Therefore, these SRs are modified by Notes that state the Surveillances are not required to be perfomed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after the specified reactor steam done pressure is reached, l.b IAf a4 3.s,1J s

A 92 day Frequenc for SR'3.5.313 is consistent with the Inservice Testing P ram requirements. The 18 month Frequency for SR 3.5. is based on the need to perfom this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if -

the Surveillance were performed with the reactor at power.

Operating experience has shown that these components usually pass the SR when performed at the 18 month Frequency, which is based on the refueling cycle. Therefore, the frequency was concluded to be acceptable from a reliability standpoint.

~

SL 3.5.3.5 The RCI a is required to actuat cally to perfors its '

function. This tillance verifies that with a requ . system ini+ on signal (actual or simulated) the automa in ion logic of RCIC will cause the system to operate a i ned, including actuation of the system througho ' ts ese a operating sequence, automatic pump up and actuat all automatic valves to their re d positions. This Su ' lance test also t

(continued)

M/S SIL B 3.5-23 Rev. u, u9/28/92 s

- t, .

l

~ .

ECCS-Operating I B 3.5.1 )

a BASES ,

t 7

SURVEILLANCE REQUIREMENTS SR 3.5.1.I f@

f FL i

(continued) The ECCS subs tems are i

perfom the design quired to actuate automatically to  ;

verifies at, with nctions. This Surveillance test i a tual required system initiation signal simulate , the automatic initiation log:e of ,

(' , , and-L will cause the systems or subsystems to t operate as designed, including actuation of the system  :

throughout-its emergency operating sequence, automatic pump startup, and actuat  :

on of all automatic valves to their  !

recuired positions. This Surveillance also ensures that the  ;

f NHSystest' ill automatically restart on an RPV low water J 1evel (Leve signal received subsequer.t to an RPV high  !

1. gcyc- water level Level 8) trip and that the suction is ,

t automati ly transferred from the CST to the suppression pool.

e LOGIC SYSTEM FUNCTIONAL TEST performed in  !

f,5 LC0 i

g .3.5.1 overlaps this Surveillance.to provide complete j sting of the assumed safety function.

i  ;

The 18 month Frequency is based on the need to perfom this  !

g Surveillance under the conditions that apply during a plant.

outage and the potential for an unplanned transient if the .

N' $ g v2 Surveillance were perfomed with the reactor at power. l Operating experience has shown that these components usually  !

pass the SR when perfomed at the 18 month Frequency, which ,

is based on the refueling cycle. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.  !

This SR is modified by a Note that excludes vessel

.I injectionZRpest during the Surveillance. Stace all active components are testab i e and full flow can be demonstrated by recirculation through the test 1tne, coolant injection into the RPV is not requ< red during the Surveillance. ,

SR 3.5.1.

The ADS designated S/RVs are required to actuate automatically upon receipt of specific initiation signals.

A system functional test is wrfomed to demonstrate that  !

the mechanical portions of tie ADS function (i.e.,

solenoids) operate as designed when initiated either by an ,

i actual actuationor of simulated all the required initiation signal, components. SR 3.5.1.causing 8/ prope[r ancI the LOGIC SYSTEM FUNCTIONAL TEST perfomed in LC0 3.3.5.1 (continued)

$BWR?ESTS B 3.5-11 L. G, 0;/20/02

. e.vv. e n o arm er avuxanwu a er r;mnr -

, , ECCS-Operating j B 3.5.1  !

t BASES SURVEILLANCE SR 3.5.1.

REQUIREMENTS (continued) overlap this Surveillance to provide complete testing of the assumed safety function.  !

The 18 month Frequency is based on the need to perfom this  ;

Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the

• Surveillance were performed with the reactor at power.

Operating experience has shown that these components.usually pass the SR when perfomed at the 18 month Frequency, which is based on the refueling cycle. Therefore, the Frequency 1

was concluded to be acceptable from a reliability standpoint. ,-

j This SR is modified by a Note that excludes. valve actuation, This prevents an RPV pressure blowdown.

3 SR 3.5.1.1  !

4 A manual actuation of each ADS valve is performed to. verify i that the valve and solenoids are functioning properl that no blockage exists in the S/RV discharge lines.y and This is demonstrated by the response of the turb' ne control'or i bypass valve, by a change in the measured steam flow, or by any other method suitable to verify steam flow. Adequate reactor steam done pressure must be available to perform this test to avoid damaging the valve.

Sufficient time is therefore allowed, after the required pressure is achieved,

[ 6 6.8 %[Mk, is toperfom to this istest.f[,Ade be perfomed 95 uste fressure at which '

this te by the valve manufactrrer . psig (the pressure recommended Reactor startup is allowed i

prior to performing this test because valve OPERABILITY and 1 the setpoints for overpressure protection are verified, per )

ASME requirements, prior to valve installation. Therefore this SR is modified by a Note that states the Surveillance, is not required to be p ormed steam done pressure is 50 psi til 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reactor i SR 3.5.1. and the LOGIC SYSTEM FUNCTIONAL TEST l rfomed n LC0 3.3.5 I overlap this  :

Surveillance to provide complete testing of e assumed safety function.

66.t KSicM3 f The Frequency of 18 months on a STAGGERED TEST BASIS ensures that both solenoids for each ADS valve are altemately tested. The Frequency is based on the need to perform this (continued)

ABWRXSTS B 3.5-12 Rev. O, 09/28/92

s ECCS-Operating B 3.5.1 B?.SES 9

SURVEILLANCE SR 3.5.1.X (continued)

REQUIREMENTS SurveOlance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were perforud with the reactor at power.

Operating experience has shown that these components usually pass the SR when perfomed at the 18 month Frequency, which is based on the refueling cycle. Therefore, the Frequency was concluded to be accept 6ble from a reliability standpoint.

AGWA. S REFFAENCES 1 /SAR, Sectionk 6.3.2 g

2. TSA",, R:ti er. [':.3,7 'I.4] . -

2. 75.'"., 5:: tin [0.3.2.2.137 T;3 , 3rdion [6.3.2.2 0

~

(SAR,Section .2.0 .

A % ) /SAR, Sectio D 15.6.4 [

@ (SAR,Section)15.6.57

-+

6 8. 10 CFR 50, Appendix K.

s

& 1) /SAR, Section3 6.3.3 [

7 M. 10 CFR 50.46.

n. r;=, neu= [:. .3.3 .

jihi"h JE3di5diEJL',; t"!!;'/Br ECCS C g =;i.ta " A s ew, 1, 1975.

23. T0AR, %:ti:- [S.2.2.7.0] .

1 fSAR,SectioD7.3.1.1.1.

g, p $w A siAA, set Hos &.339 L

9. c i.ca e3 st. 10 C F A 5b , ft PPe ^ h ix h, C-l b c 33

c. A6W A 55 A Aj S e c +7u 4. 7 hBWR/ESTS B 3.5-13 an. O, 0;/;;/02-

_ _ _ _ ,m _ _m.-. _ - , , -