ML20113B589

Proposed Tech Specs,Removing Request to Relocate MSIV Full Closure Time Requirement to Program Administratively Controlled by TS & Revising Associated Bases to Include Info to Clarify Expanded Bases Specific to CPSES

ML20113B589
Person / Time
Site:	Comanche Peak
Issue date:	06/21/1996
From:	TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:
Shared Package
ML20113B587	List: ML20113B583 ML20113B589
References
NUDOCS 9606270223
Download: ML20113B589 (6)

Text

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6 ATTACHMENT 2 TO TXX 96384 AFFECTED TECHNICAL SPECIFICATION PAGES (NUREG 1468)

" Technical Specification, CPSES Units 1 and 2" i

[Pages 3/4 7-8, Insert A Pages 1, 4, and 5,]

and Insart B Page 1]

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i l

l 1

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9606270223 960621 PDR ADOCK 05000445 P PDR

Attachment 2 to TXX-96384 Page 1 of 5 PLANT SYSTDt3 MAIN STEAM LIMF ISOLATION VAtVES LIMITING crumtTION FOR OPERATION y Fea Mssvs 3.7.1.5 Rach main steam line isolation valve (MSIVD shall be OPERA APPLICAaILITY: MODES 1. 2, and 3 EllM:

MODE 't:

STAW UD *e. next 6 h=rs ,

With one M51V i wperable but spes POWER OPERAT!0N may con nue provided 6 the inoperable talve is restored ,to 0 PEP!"f status within ours:

his mise theberoiiovins iMMUT IThy within the next 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> ane in MUT SHUTnrum]r' a hoursJ ,

~

M 3 m 94_

i s With one provided"M5tVfinoperable, the nsavanan vaivants sudeeu,ent eseraties MBE 2 or 3 may in proceed 113adFclosed , otherwise, he in HOT STAM BY within the next 4 hou'rs '

a NIFI' SWTOC 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Al within the following l suavEItimeer araut_ m

4. 7.1.5n Each witmin ==-- ,IF M shall be demonstrated OPEMBLE by verifyt

! fu 1 losu s'vr ubestested.pursuanttoSpecification4.0.5. provis i

of spectficatten 4.8.4 are met applicable for entry inte MODE 3.

d I

I

h bh ( OO O k%% $ $

for8cd M5tV. h i

i COMMCHE PEM - WITS 1 AM 2 3/4 T-8 i

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Attachment 2 to TXX-96384 r Pdge 2 of 5' 8

-s -

aswh h fB '3.7 PLANTSYSTDtS\

( B 3.1.2 MainSteamIsolationvalves(M51Vs)]

e.

QASE5]~

A K ROUND The MSIVs isolate steam flow from the secondary side of the Ea&, pseg 3 o

Q steam generators following a high energy line break (HEL8). I

+breQ fnount Iej.,t,$n fnh' p M51V closure terminates flow from the unaffected (intact) steam generators.

,(e gegey

,g 4gg y, r a+mesekerie.

'" ' Ee dc.h hos %ce e.

M 'o^5 Wp'c.h cre. dcse,; One MSIV is located in each asin steam line outside, but close to, containment. The M51Vs are downstream from the g>ute ord epen, wfL '

pemc3 re. turn to aato pe5rhen. in steam safety valves (M55Vs) and auxiliary feedwater 6e Tro,n A w Tecon 3 -

AFW) pump turbine steam supply, to prevent M55V,[ane AFw A" solation from the steam generators by M51V closure.

cor.ke t s are c@in e d m losing the M5!Vs isolates each steam generator.from the Pac,6 hc nd 3g,j.c h others, and isolates the turhine,/ team stem, and pI other auxiliary steam supp11es from the steam rators.

., 3% g,. The MSIVs close on a main steam isolation ignal generated Pre ssum ca,,0c, p by either low steam generator pressure ich containment ro+t eW.gh pressue one ws mi casas an aan a, -nm as A rac= nan TJg L.g d' E ^'"r' jJbr'e 9m Each M51V has an M5!V bypass valvd "AliDeegh these oypass S r vai ves are rue. -s iy c ieuse, s. , . w ri ve the ng e- c' osure sianal as de their associated MEIVs. i Vs may' l vaWes em h* . ,4 u g % j dosed tr.wn 8 a'se be actuated manually. w Mor% .e,n,e eh Ne .

A description of the MEIVs is found in**#*** the 4'*F5An,~

• ',e Section 10.3] (Ref. 1). *'* g5 l er s.z,..u APPLIr.AeL E The easign easts of the MEIVs is established by the g

SAFETY ANALYSES containment analysis for the large steam line break ($LB) inside containment discussedintheFSAR,Section(5.2]

(Ref.2). It is aIse affected by the accident analysis of theSLSeventspresentedintheF54R.Section(15.1.5)

(Asf.3). The design precludes the bloudeus of more than one steam generater, assuming a single active component i failure (e.g., the fallers of one M5tv to close on demand).

The Ilmiting case for the containment analysis is the SLS inside containment, with a less of effsite peser following turhine trip, and failure of the M5IV em the effected steamj (continued) a - o diOG STX) ' (T3.7 D Gav. O, og/28/g2)

Attachment 2 to TXX-96384 Page 4 of E g gy, 3J.2 APPLICABILITY In MODE 4, nomally most of the MSIVs are closed, and the (continued) steam generator energy is low.

In MODE 5 or 6, the steam generators do not contain much energy because their temperature is below the boiling point of water; therefore, the M5!Vs are not required for isolation of potential high energy secondary system pipe i breaks in these MODES.

s ACTION ricof. I :

With one MSIV inoperable in action must be taken to restore OPERA 8tE status within rs. 5 airs to tJeMSIVcanbemadewiththeun hot. The ur  !

acompletiongfies is reasonable, considering th ou probability of an accident occurring during this time period that would require a closure of the MSIVs.

The hourgospletion/les is greater than that nornelly all for containment isolation valves because the M5IVs are valves that isolate a closed system penetrating Tc g , gw3-fWs Achon containment. These valves differ from other conta<nment

""j yd isolation valves in that the closed system d e b e- additional means for containment isolation.provides an

, 4 and cwp ehen i hines Me b-es ge hd ,,g 4,e Adam M M McDES lod 3 MCM comp I eMe O' dess,ysW "hN '

to be.bodeg on a P vave u M51V cannot be restored to status within basis. When dve 15 cjecjyre,) L iours, the unit must be placed in M in which the imp e ,$M ^ " does not apply. To achieve this tus . the unit must I enFe and 6 mwfjeh h entered. 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> mewould be tirn e_ dMS - M beplacedinMODE2witkifleesareroe The M letion e, based on operating experience, to reach IWDE 2 and to close the MSIVs fs each vaWe. and sep

!5 0,.

Mgg

> la as orderly meaner and without challenging unit systems.

g[ .1 qad C y -MonEs Z M

• od,.o statemed

'5

• h s i b IIste ingthatsepGatef Since the M51Vs are required to be OPERABLE in MODES 2 and 3, the inoperable M51Vs any either be restored to (continued) o a tai sis ) Cs 3.7-10 y diipv. o09/28/92h p w+ k , Pafe (4) %: 5)[

--w -- w- ,s - w ,-a- y w-r7 e1--wrw- - = w - - ee -ir-- vrw - = ew--'

Attachment 2 to TXX-96384

• o Page 5 of 5

/~M51VsT L8 3.7.21

.o W

Me5 *1 *0 A ACTIONS (C.1 and C.ff (continued)

OPERA 8LE status or closed. When closed, the MSIVs are already in the position required by the assumptions in the safety analysis.

The Mourjompletiongime is consistent with that allowed in n-m- o.se i 4cruw .

For inoperable MSIVs that cannot be rest,ored to OPERA 8tE status within the specified gospletionJime, but are closed, the inoperable MSIVs must barverified on a periodic basis to be closed. This is necessary to ensure that the assumptions in the safety analysis remain valid. The 7 daygompletion

/Ime is reasonable, based on engineering judgmeft, in view of M51V status indications avai'able in the control room, and other administrative controls, to ensure that these ,

i valves are in the closed position. -

(b.1 w 0.27 If the M51Vs cannot be restored t OptRA8LE status or are not closed within the associated lationgime,theunit must be placed in a MODE in whi the LCO does not apply.

To achieve this status, the unit must be placed at least in MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed gompletion /imes are reasonable, based on operating experience, to reach the required unit conditions from MODE 2 conditions in an orderly manner and without challenging unit systems. '

l 4.1.C.K , i e~.:...s.1 .. i R E 5 This SR verifies that MSIV closure infThe hueconds)

__o.+ .

on an actual or simulated actuation signal. MSEt . MT, i u n-' '~. closure n eJis assumed in the accident and containment gg- analyser. Inis Surveillance is nones 11y performed upon returning the unit to operation following a refueling outage. The M51Vs should not be tested at power, since even a part stroke exercise increases the risk of a valve closure when the unit is generating power. As the MSIVs are not tested at power, they are exempt from the ASIE Code, (continued) w srs; _ a 2.7.10 e_

a.v . o, o,ns/90

. Jh u > , kelnagtf

Attachment 2 to .TXX-96384

- , Page 3 of S

• b9N b .

1 APPLICABLE SAFETY ANALYSES:

! The basis for the MSIV operability is derived from their assumed operation in the accident analyses of the breaks in the secondary system (principally, steamline l break). The design of the secondary system precludes the uncontrolled blowdown

of more than one steam generator, assuming a single active component failure (e.

j g., the failure of one MSIV to close on demand). In addition, the MSIVs are credited in the analyses of the steam generator tube rupture accidents.

I in the safety analyses, several different SLB events are compared against different event acceptance limits. A double-onded guillotine SL8 at hot zero power is the limiting case with respect to the com response. The double ended guillotine SLB outside containment upstream of the MSIV is limiting for offsite dose "N" consequences, although a break in this short section of gping has a very low

=;n.. of the MSIVs in the i probability.

steam tunnels from A 1.0 ft' non-mechanistic at-power conditions is limit breakp;ing with respect to

}

j qualification in the steam tunnels. A large SLS st higher power levels is limiting with respect to maximum containment temperature used for equipment j

qualification. In the analyses of the feedwster line break and steam generator tube i

rupture accidents, the MSIVs are credited for steam generator isoletion. A i

significant failure considered for all cases is the fadure of a MSIV to close. -

^

(emd hew kWs im#m 4 te clue, on b.C The MSIVs :: :: : '; ::"z; t :"- :

• remain open during power operation [

These valves are assumed to operste under the following situatione:

4 l a.

A HEL8 (SL8 or FL8) inside containment. In order to maximize the mass and i

energy release into containment, the analyses assumes that the MSIV on the affected steam generator fails to close. For this scenario, steam is discharged into containment from all steam generators until the remaining ,

MSIVs close. After MSIV closure, steem is discharged into containment only {

from the affected steam generator and from the residual steam in the main l steam piping downstream of the closed MSIVs in the unaffected loops.

Closure of the MSIVs isolates the break from the unaffected steam generatore.

.