ML20236J082
| ML20236J082 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/29/1998 |
| From: | UNION ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20236J074 | List: |
| References | |
| NUDOCS 9807080036 | |
| Download: ML20236J082 (22) | |
Text
{{#Wiki_filter:. . ULNRC-03854 Attachment 1 Steam Generator Atmospheric Steam Dump Valves Marked-up Current Technical Specifications T/S 3.7.1.7 T/S 4.7.1.7.1 T/S 4.7.1.7.2 Bases 3/4.7.1.7 9807080036 980629 PDR ADOCK 05000483 P PDR
RLANT SYSTEMS - S EAM GENERATOR ATMOSPHERIC STEAM OUMP VALVES LIMITING CCp ITION FOR OPERATION 99 , Four 3.7.1.7 4 'ee : :": : shall be OPERABLE. steam generator atmospheric steam dumph (A394p) Jje I APPLICABILITY: Modes 1, 2 and 3.
.J ACTMT: A$D .b5W a.
With one of th required ASD% 'noperable due to causes other than excessive seat leakage, within 7 days restore the ASDgo OPERABLE stetus, or be in HOT STAN0BY within 6 hours and in .
.. HOT< SHUT 00WN within the followina % ho'u rs. /
pNSERT A3 > ~4 '
-b .3 'ith m: e thaa nne of *he ran"irad ^50': i noperab1.e -duc - t>
<aucc: othcr than cxcer:f /c sc;t icdkege, w Fchia 24 bcm ir l r= stere e* T east wc cf thequi d ^>SC':- tc 0"ERACL: nm wa in HOT cm!DE Y : thin :5: =: E Meur: : nd i n TJ ""m L uit* the ft41ce'r.; E hcur3.
rn m 0Lo 1 c} , )(. ASD(s) bo4H'a With one or more of the required iese:s* inoperable because of excessive seat leakage, close the associated ' valve (s) and restore the '.:: to OPERABLE status within 30 days, or te in HOT STANDBY within 6 h 're . folicwing and in HOT SHUTDOWN within tne I hours.(q g The provuions of Specification 3.0.4 are not applicable. SURVE!LLANCE REQUIREMENTS 4.'L 1.7,i Vee:h om. c.ompte.k. cpo c4 e4cA ASD in ausdwa. to;# 6 dE' P eden I d.7.1.7 Nc-ed ition:1 c:cim: ment: :ther d'O'
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bec:fice;,co 4 . 0 .-5 . The provisions of Soecifica: ::ui :q ' ion 4.0.4 are net applicable for entry into Mode 3.
- 4. 9,1.7. 2
\lerih om_ cornplek ga d =A ASD mwud isoldh y h in a.ctadua_, m; @ spedhh 4.0,5.
CALLAWAY - UiHT I 3/4 7-9b k endment Nc. W , H
tr s . .. I I . INSERT A ~
- b. ..With two of the required ASD lines inoperable due to causes other -
than excessive ASD seat leakage, restore all but one required ASD: H I : line to OPERABLE status within 72 hours or be'in at least HOT
- STANDBY within the next 6 hours and in HOT SHUTDOWN ~ '
within the followin312 hours.
- c. - With threc or more of the required ASD lines inoperable due to causes other than excessive ASD seat leakage, restore all but two required ASD lines to OPERABLE status within 24 hours or be in.
L_- at least HOT STANDBY within the next 6 hours and in HOT SHUTDOWN within the following 12 hours. i-
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4 ., PLANT SYSTEMS BASES 3 /4 '. 7.1. 5 MAIN STEAM LINE ISOLATION VALVES The OPERABILITY of the main steam line isolation valves ensures that. no.more than one steam generator will blow down in the event of a steam
'line rupture. This restriction is required to: (1) minimize the positive reactivity effects of the Reactor Cool:.nt System cooldown associated with the blowdown, and (2) limit the pressure rise within containment in the event the steam line rupture occurs within containment. The OPERABILITY of the main steam line isolation valves within the closure times of the Surveillance Requirements is consistent l with the assumptions used in the safety analyses.
3/4.7.1.6 MAIN FEEDWATER ISOLATION VALVES The OPERABILITY of the main feedwater isolat. ion valves: (1) provides a pressure boundary to permit auxiliary feedwater addition in the event of a scain steam or feedwater line break; (2) limits <the RCS cooldown and the oss and energy releases for secondary line breaks inside containment; and (3) mitigates steam generator overtill events such as a
' feedwater malfunction, with protection provided by feedwater isolation via the steam generator high-high level trip. signal. The OPERABILITY of the main' feedwater isolation valves within the closure times of the Surveillance Requirements is consistent with the assumptions used in the safety analyses.
3/4.7.1.7 STEAtLGENERATOR ATMOSPHERIC STEAM DUMP VALVES
' insert C)
The OPERABILITY of the steam generator atmospheric steam dump c:P::: (ASUV 1t ) ensures that the reactor decay heat can be dissipated to the atmosphere in the event of a steam generator tube rupture and loss of offsite power and that. the Reactor Coolant System can be cooled down for Residual Heat Removal System operation. The number of required ASD% f 'w assures that the subcooling can be achieved, consistent with the
'r dN assumptions used in the steam generator tube rupture analysis, to 1 facilitate equalizing pressures between the Reactor Coolant System and theVf=1ted steam generator. fer :::lin; -the9hntato,""E ' " ' tier -
; = dit i = , 4 = : " m : ; 9 M . Iw=tM s cese, ,ii-th4hree "%
OPERACLE, if theerdngh-kihr: :f ae-ASB vccccr nG6er-ASD-.14-
- asumed iu_lae_assuv;.ted with thdeutted-steam-genwate. = f.50 l
!: rema4m availablenfor reired t. cat =Te3 ova &. f3psggy y ! L ,, t
, I))3 i heh-ASDhquipped;wilh -i-manual-blockly4ixe. (iii_the-ettx4Mery i htriitHim) to provide-e positive-shutoff-capabitity-shotrWan=ACO develop i h gc. C4nur-e of.:the= block-v4Lves-of-ali-ASDS'-becattse-efwxcessh l
- h. saat-Isak-age-dou-not endanger-the-reaetchure, consistent =with-phet- l 1
CALLAWAY - UNIT 1 B 3/4 7-3 Amendment No. 48 7 -457 103 1 1 1
INSERT C lines (each ASD line consists of one ASD and associated manual isolation valve) \ INSERT D In the event of a SGTR, two intact steam generator ASDs are required for rapid cooldown to achieve the necessary subcooling. In this case, with four ASD lines OPERABLE, if the single failure of one ASD line occurs and another ASD line is assumed to be 3 associated with the ruptured steam generator, two intact steam generator ASD lines remain a callable for required heat removal. Each ASD line is equipped with a manual isolation valve (in the Auxiliary Building) to provide a positive shutoff capability should an ASD develop neakage or fail open. Closure of the manual isolation valves of all ASD lines, because of excessive ASD seat leakade, does not endanger the reactor core; consistent with plant
PLANT SYSTEMS
. i l . ' BASES' i l
3 /4. 7.1. 7 STEAM GENERATOR ATMOSPHERIC STEAM DUMP VALVES (Continued) l m & M io D l' accident and transient analyses, decay heat can be dissipated with the main steamline safety valves or a valve can be opened manually in the auxiliary building and the ASD can be used.to control release of steam to the atmosphere. For the steam generator tube rupture event, ; primary to secondary leakage can be terminated by depressurizing the i Reactor Coolant System with the pressurizer power operated relief valves.
< "1n ser t B> '
, l 3/4.7.3 COMPONENTCOOLINGNATERSYSTEM s The OPERABILITY of the Component Cooling Water System ensures that sufficient cooling capacity is available for continued operation of safety-related equipment during normal and accident conditions. The redundant cooling capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety analyses. Each independent CCW loop contains two 100% capacity pumps and, therefore, the failure of one pump does not affect the OPERABILITY of that loop.
3/4.7.4 ESSENTIAL SERVICE WATER SYSTEM The.0PERABILITY of the Essential Service Water System ensures that sufficient cooling capacity is available for continued operation of : safety-related guipment during normal and accident conditions. The I redundant cooling capacity of this system, assuming a single failure, is ! a consistent with the assumptions used in the safety analyses. 3/4.7.5 ULTIMATE HEAT SINK-The limitations on the' ultimate heat sink level and temperature ensure that sufficient cooling capacity is available either to: (1) provide normal cooldown of the facility, or (2) mitigate the effects of accident conditions within acceptable limits. l 4 l
.CALLAWAY - UNIT 1 B 3/4 7-3a Amendment No. -45 103 L
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5 4 . INSERT B With o.ie required ASD line inoperable due to causes other than excessive ASD seat leakage, ACTION must be taken to restore the ASD line to OPERABLE status within 7 days. LThe 7 day allowed outage time allows for the redundant capability
' afforded by the remaining OPERABLE ASD lines, a nonsafety grade backup in the
., condenser steam dump system, and main steam safety valves. This required ACTION is modified by a Note indicating that LCO 3.0.4 does not apply.
With two ASD lines inoperable due to causes other than excessive ASD seat leakage, ACTION must be taken to resto:e all but one required ASD line to OPERABLE status within 72 hours. The 72 hour allowed outage time is reasonable to repair Einoperable ASD lines based on availability of the condenser steam dump system and/or main steam safety valves and low probability of an event occurring during the period : hat would require function of the ASD lines. With three or more ASD lines inoperable due to causes other than excessive ASD L seat leakage, ACTION must be taken to restore all but two required ASD lines to
! OPERABLE status within 24 hours. The 24 hour allowed outage time is reasonable to repair inoperable ASD lines based on availability of the condenser steam dump system and/or main steam safety valves and low probability of an evert occurring during the f period that would require function of the ASD lines.
.With one or more ASD(s) inoperable.because of excessive seat leakage, ACTION must be taken to close the associated manual isolation valve (s) and within 30 days to restore the ASD(s) to OPERABLE status. . This 30 day allowed outage time limits the period in which a manual isolation valve is closed due to excessive seat leakage of the 1
- ASD and minimizes the delay associated with manually opening a previously closed manual isolation valve. This required ACTION is modified by a Note indicating that LCO 3.0.4 does not apply.
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l ULNRC-03854 s Attachment 2 Steam Generator Atmospheric Steam Dump Valves , Proposed Current Technical Specifications - Clean Copy - T/S 3.7.1.7 T/S J.7.1.7.1 - T/S 4.7.1.7.2 - Bases 3/4.7.1.7 l [, i
f i
, . PLANT SYSTEMS j i'
STEAM GENERATOR ATMOSPHERIC STEAM DUMP VALVES l'IMITING CONDITION FOR OPERATION 3,7.1.7 Four steam generator atmospheric steam dump (ASD) lines shall be OPERABLE.
. APPLICABILITY:: Modes 1,2 and 3.
ACTION:.
- a. With one of the required ASD lines inoperable due to causes other than excessive ASD seat leakage, within 7 days restore the required ASD line to OPERABLE status, or be in HOT STANDBY within 6 hours and in HOT SHUTDOWN within the following 12 hours. The provisions of Specification 3.0.4 are not applicable'.
- b. With two of the required ASD lines inoperable due to causes other than excessive ASD seat leakage, restore all but one required ASD line to OPERABLE status within 72 hours or be in at least HOT STANDBY within the next 6 hours and in HOT SHUTDOWN within the fotbwing V 12 hours.
c.; With three or more of the required ASD lines inoperable due to causes other than excessive ASD , seat leakage, restore all but two required ASD lines to OPERABLE status within 24 hours or be in j at least HOT STANDBY within the next 6 hours and in HOT SHUTDOWN within the following J 12 hoursc
' d. With one or more of the required ASD(s) inoperable because of excessive seat leakage, close the ' ,
I associated manual isolation valyc(s) and restore the ASD(s) to OPERABLE status within 30 days, . ' or be in HOT STANDBY within 6 hours and in HOT SHUTDOWN within the following ' -{ 12 hours. The provisions of Specification 3.0.4 are not applicable, j i SURVEILLANCE REQUIREMENTS j 4.7.1.7.1 Verify one complete cycic of cach ASD in accordance with Specification 4.0.5. The prosisions of Specification 4.0.4 are not applicable for entry into Mode 3. 4.7.1.7.2 Verify one complete cycle of each ASD manual isolation valve in accordance with Specification 4.0.5. ! l I. ! !~ I (: CALLAWAY - UNIT C 3/4 7-9b Amendment No. 59
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;fg PLANT SYSTEMS j E
' i BASES
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'3'/4.7.1.5' MAIN STEAM LINE ISOLATION VALVES '
The OPERABILITY of the main steam line isolation vahes ensures that no more than one steam generator
' will blow down in the event of a steam line rupture. This restriction is required to: (1) minimize the positive f reactivity effects of the Reacter Coolant System cooldown associated with the blowdown, and (2) limit the pressure rise within containment in the everit the steam line rupture occurs within containment The OPERABILITY of the main steam line isolation vahes within the closure times of the Surveillance Requirements is consistent with the assumptions used adhe safety analyses.
, j 3/47.1.6 ' MAIN ETDWATER ISOLATION VALVES l The OPERABILITY of the main feedwater isolation valves: (1) provides a pressure boundary to permit
'U'
~ auxiliary feedwater addition in the event of a main steam or feedwater line break; (2) limits the RCS cooldown and the mass and energy releases for secondary line breaks inside containment; and (3) mitigates steam generator -
- overfill events such as a feedwater malfunction, with protection provided by feedwater isolation via the steam generator high-high level trip signal. The OPERABILITY of the main feedwater isolation valves wthin the closure times of the Surveillance Requirements is consistent with the assumptions used in the safety analyses.
3/4.7.1.7 STEAM GENERATOR ATMOSPHERIC STRAM DUMP VALVES : The OPERABILITY of the steam generator atmospheric steam dump (ASD) lines (each ASD line consists of one ASD and associated manual isolation valve) ensuits that the reacter decay heat can be dissipated to the
' atmosphere in the event of a steam generator tube rupture and loss of offsite power and Jint the Reactor Coolant ,_ System can be cooled down for Residual Heat Removal System operation. LThe number of required ASD. lines assures that the subcooling can be achieved, consistent with the assumptions' used in the steam generator tube -
rupture analysis, to facilitate equalizing pressures between the Reactor Coolant System'and the ruptured steam . Qenerator. jIn the event of a SGTR, two intact steam generator ASDs are required for rapid cooldown to achieve the necessary subcooling.' In this case, with four ASD lines OPERABLE, if the single failure of one ASD line occurs 1
; and another ASD line is assumed to be associated with the ruptured steam generator, two intact steam generator ASD lines remain available for required heat removal.
Each ASD line is equipped with a manual isolation valve (in'the Auxiliary Building) to proside a positive
; shutoff capability should an ASD develop leakage or fail open. Closure of the manualisolation valves of all ASD lines, because of excessive ASD seat leakage, does not endanger the reactor core; consistent with plant w
(_ t a r i 1 CALLAWAY - UNIT 1 ' B 3/4 7-3 Amendment No. 4b44; 103 5i g k -- -
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1 i a' PLAN r SYSTEMSI ' 8 i L ' BASES'
, '3[4.7.1.7' STEAM GENERATOR ATMOSPHERIC STEAM DUMP VALVES (Continued) accident and transient analyses, decay heat can be dissipated with the main steamline safety valves or a manual ,
t9 isolation valve can be opened manually in the auxiliary building and the ASD can be used to control relcase of j steam to the atmospherc.i For the steam generator tube rupture event, primary to secondary leakage can be S. ' terminated by depressurizing the Reactor Coolant 3ystem with the pressurizer power operated relief valves. ' w . With one required ASD line iruperable due to causes other than excessive ASD seat leakage? ACTION L must be taken to restore the ASD line to OPERABLE status within 7 days. The 7 day allowed outage time allows
. for the redundant capability afforded by the remaining OPERABLE A3D lines, a nonsafety grade backup in the condenser steam dump system, and main steam safety valves. This required ACTION is modified by a Note -i o indicating that LCO 3.0.4 does not apply.. .)
With two ASD lines inoperable due to causcs other than excessive ASD seat leakage, ACTION must bc
. taken to restore all but one required ASD line to OPERABLE status within 72 hours. The 72 hour allowed outage time is reasonable to repair inoperable ASD lines based on availability of the condenser steam dump system and/or
, main steam safety valves and low probability of an event occurring during the period that would required function of the ASD hnes
. With three or more ASD hnes roperable due to causes other than excessive ASD seat leakage, ACTION ' ,
. must be taken to restore all but two required ASD lines to OPERABLE status within 24 hours. The 24 hour allowed outage time is reasonable to repair inoperable ASD W t rt. .. avauvs.3 .J m. wndenser steam dump system and/or main steam safety valves and low probabmty of an event occurring during tM period that would require
. function of the ASD lines.
1With one or more ASD(s) inoperable because of excessive seat leakage, ACTION must be taken to close the associated manual isoletion valvc(s) and within 30 days to restore the ASD(s) to OPERABLE status. This
- 30 day allowed outage time limits the period in which a manual isolation valve is closed due to excessive seat
- leakage of the ASD and minimizes the delay associated with manually opening a previously closed manualisolation valve. This required ACTION is modified by a Note indicating that LCO 3.0.4 does not apply. 1 1
.3/4.7.3- COMPONENT COOLINC WA_TER SYSTEM ,. l 1
\~ - I
+ The OPERABILITY of the Component Cooling Water System ensures that sufficient cooling capacity is availabic for continued operation of safety-related equipment during normal and accident conditions: The redundant p cooling capacity of this system, assu'ning a single failure, is consistent with the assumptions used in the safety L . analyses.~ Each independent CCW loop contains two 100% capacity pumps and, therefore, the failure of one pump p i does not affect the OPERABILITY of that loop.
L . .. _ J l : 3/4.7.4 ' ESSENTIAL SERVICE WATER SYSTEM p . : The OPERABILITY of the Essential Service Water System casures that sufficient cooling capacity is
' available for continued operation of safety-related equipment during normal and accident conditions. The redimdant
; cooling capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety
~
j analyses. j
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'j 13/4;7 5 ULTIMATE HEAT SINK . j
.. The limitations on the ultimate heat sink level and temperature ensure that sufficient cooling capacity is
, 'l available either tof (1) provide normal cooldown of the facility, or (2) mitigate the effects of accident conditions j 7 within -pA!c limits.-
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CALLAWAY - UN" B 3/4 7-3a Amendment No. 4h 103
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9-4 1 ULNRC-03854 Attachment 3 Steam Generator Atmospheric Steam Dump Valves l Marked-up improved Technical Specifications T/S 3.7.4 Bases 3.7.4 i l s
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I i !~ l. I i..
4 ASDs 3.7.4
'3.7.[LANTSYSTEMS l 3.7.4 Atmn*; b eic Steam Dump Valves ;ASDs) l
! Fo w LC0 3.7.4 34uumer ASD lines shall be OPERABLE. APPLICABILITY (: MODES 1, 2, and 3. ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME
'A. One required ASD line A.1 ------ --- NOTE- - ----- --
inoperabley br reofcOS LCO 3.0.4 is not 4 b gecrgh/6 applicable. y 3, ........................... Restore required ASD line 7 dcM to OPERABLE status. 72 B. Two eeeene, required ASD B.1 Restore all but one Khours lines i erabley for required ASD line to Te45eviS ASD sea.t Wd e. M OPERABLE status. A
< -( z nse<t Y J %
g. Required Action and E'.1 Be in H0DE 3. 6 hours
.6 associated Completion 5 Time not met. A!iQ
.2 Be in MODE 4. 18 hours CALLAWAY PLANT ITS 3.7 9 5/15/97
INSERT Y , C. Three or more required ASD C.1 Restore all but two 24 hours lines inoperable for reasons required ASD lines to other than excessive ASD seat OPERABLE status, leakage. D. With one or more of the - NOTE-------- reauired 49D(:)iacperable LCO 3.0.4 is not because of excessive seat applicable. leakage. ------------------------- D. ] Initiate action to close Immediately the associated manual isolation valvc(s). AND D.2 Restore ASD(s) to 30 days OPERABLE status.
. 1 ASDs 3.7.4 s j
) .SURVE1LLANCE REQUIREMENTS l
SURVEILLANCE FREQUENCY l SR 3.7.4.1 .....................N0TE.. ................. l Only required to be performed la MODES 1 and 2. j
............................................... )
Verify one complete cycle of each Aau. In accordance with the Inservice Testing Program SR 3.7.4.2 Verify one complete cycle of each ASD manual In accordance isolation valve. with the Inservice Testing Program CALIAWAY PLANT ITS 3.7 10 5/15/97 l L __
E .. I j . t.. ASDs B 3.7.4 c.
- ), .B 3.7' PLANT SYSTEMS l
B 3.7[4 Atmospheric Steam Dump Valves (ASDs)
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I
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BASES I
' BACKGROUND.- The ASDs, provide a method for cooling the unit to residual heat l l- . removal (RHR) entry conditions should the preferred heat sink via i the Steara Dump Valves to the condenser not be available, as
-discussed in the FSAR, Section 10.3 (Ref 1).. This is done in conjunction with the Auxiliary Feedwater System providing cooling water from the condensate storage tank (CST). The ASDs assure .
that between subcooling the reactorcan coolant be achieved to the system and facilitate N steam equal,1
~f zing p
)
. generator following a postulated steam generator tube rupture 4
' event. The ASDs may also be required to meet the design cooldown i rate during a normal cooldown when steam pressure drops too low ;
for maintenance of a vacuum'in the condenser to permit use of the j Steam Dump System. : 1 One ASD line for each of the four steam generatorb is provided. 9,. Each ASD line consists of one ASD and an associated manual
, isolation valve.
The ASDs are provided with upstream manual isolation valves to provide positive shutoff capability should an ASD develop seat ; leakage and to facilitate maintenance activities. The ASDs are equipped with pneumatic controllers to permit control of the cooldown rate. The ASDs are provided with a pressurized gas supply of nitrogen that, on a loss of pressure in the normal instrument air supply, automatically supplies nitrogen to operate the ASDs. One nitrogen accumulator supplies one ASD and one auxiliary feedwater control valve per steam generator. The nitrogen accumulator supply is sized to provide sufficient pressurized gar to operate the ASD for the time required for Reactor Coolant 5ystem cooldown to RHR entry condition. A description of the ASDs is found in Reference 1. g The design basis of the ASDs is established y the capability to cool the unit to RHR entry conditions. unit can be cooled to RHR entry conditions with only one steam generator and one ASD, utilizing the cooling water supply available in the CST. (continued)
-CALLAWAY PLANT ITS i BASES B 3.7 18 5/15/97
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ASDs B 3.7.4
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- BASES -
BACKGROUND The valves will pass sufficient flow at all pressures to achieve (continued) a 50*F per hour plant cooldown rate. The total capacity of the I four valves is 15% of rated main steam flow at steam generator no bad pressure. In the accident analysis presented in Reference 2, the ASDs are assumed to be used by the operator to cool down the unit to RHR M D entry conditions for accidents accompanied by a loss of offsite 92 power. The main steam safety valves (HSSVO are assumed to , operate automatically to relieve steam and maintain the steam ' j generator pressure below the design value. For the recovery from j s a steam generator tube rupture (SGTR) eventf the operator is also
%g .
required to perform Mite cooldowrya establish adeauate using subcooling as a.necessary step to terminate the primary to -hjo secondary break flow into the ruptured steam generator. The time
- required to terminate the primary to secondarI SGTR is more critical than the time required to cool down to RHR gens /a. LDHj conditions for this event and also for other accidents. Thus, l the SGTR is the limiting event for the ASDs. The number of ASDs 1
.r required to be OPERABLE to satisfy the SGTR accident analysis p# requirements ic;2r;;. If a single failure of onemurs and i ^
another is associated with the f: ult:2SG. would remain OPERABLE for heat removal. uph4n ido The ASDs are equipped with manual isolation valves in the event an ASD spuriously fails to ooen or fails close during use, i The ASDs satisfy Criterion 3 of 10 CFR 50.36 (c)(2)(ii). A. A LC0 AFad
% 2rx ASD lines are require to ERABLE. One ASD line is feo inM required from each of team generators to ensure that at
'ieast# eneW6=heewe available to conduct i rit 001 6 -
by( T i g \p 58 following an SGTR, in which one steam generator becomes 00 0# s unavailabig accompanied by a single, active failure of a second ASD line on an unaffected steam generator. The manual isolation valves must be OPERABLE to isolate a failed open ASD line. -A-gh Jp Ed ... nuel-i-xl et . ... ;2' = ":: .~,.mi, it er it: ASD lire
-ineMid=tecause sue rtetM ;p;r;t r xtier, ti...c iv spen thm yj aamrtrl-nela +, i;le inappu 6 ... the x iiat onely;i; gg q, h ^. 7 The accident analysh that credit OPERABILITY of the ASDs require)( them to relieve steam to the atmosphere in order to '
perform their safety related function. (continued) CALLAWAY PLANT ITS - BASES B 3.7 19 5/15/97
l ASDs B 3.7.4
') ..
' BASES LC0 Failure to meet the LC0 can result in the inability to achieve (continued) subcooling, consistent with the assumptions used in the steam ,
generator tube rupture analysis, to facilitate equalizing pressures between the reactor coolant system and the ff ted steam generator,
,5 1
An ASD is considered OPERABLE when it is capable of providing controlled relief of the main stea flow aod capable of fully opening and closing on demandq Insert i Each nitrogen accumulator tank supplies one RAFP control valve 4 and one steam generator atmospheric steam dump valve. The tanks I must be maintained at a pressure sufficient to ensure a five hour supply for the ASDs and the TDAFP flow control valves to be considered.0PERABLE. The five hour supply is the minimum
. required for mitigation of a 530 or SGTR (Ref. 4). ,
1 l
~ APPLICABILITY In MODES 1, 2. and 3. the ASD lines are required to be OPERABLE.
N In MODE 4. the pressure and temperature limitations are such that the probability of a SGTR event requiring ASD operation is low. 1 In addition, the RHR system is available to provide the decay l heat removal function in MODE 4. Therefore, the ASD)[ re not required to be OPERABLE in H0DE 4. ! In H0DE 5 or 6, an SGTR is not a credible event. b ACTIONS u & ASD W b Fogg3Q $ 7eIt QuMAS e-With on required ASD line inoperable, action m st be taken to restor PERABLE status within 7 days. The 7 day Completion Time allows for the redundant capability afforded by the remaining OPERABLE ASD lines, a nonsafety grade backup in the Condenser Steam Dump System, and HSSVs. Required Action A.1 is modified by a Note indicating that LC0 3.0.4 decs not apply. 6 (TMSER~r % - C 'I 41 po, (e Agp sd djg ,' With twe o more required ASD lines inoperabidt' a n mus taken to restore all but required ASD linesto OPERABLE (continued) CALLAWAY PLANT ITS BASES B 3.7 20 5/15/07
ce
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INSERT 1
. and not experiencing excessive seat leakage. Excessive seat leakage, although'not i associated with a specific acceptance criter. ion, exists when conditions dictate closure of
~
the manual isolation valve to limit leakage. j j 1 INSERT X . t y J j l Bd
=
With two required ASD lines inoperable for reasons other than excessive ASD seat s Eleakage, action must be taken to restore all but one required ASD line to OPERABLE-
~ status. Siace the manual isolation valve can be closed to isolate an ASD, some repairs -
may be possible with the unit at power. The 72-hour Completion Time is reasonable to : repair inoperable ASD lines, based on the availability of the Condenser Steam Dump System and/or MSSVs, and the low prob'a bility of an event occurring during the ;
. restoration period that would require the ASD lines.
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M_=_=- __ --- - =- -
3 g., . ASDs
, B 3.7. 4 y
+ - .
r BASES' .-
.g ACTIONS '11'(continued)
' status. Since the manual isolation valve can be closed to isolate an ASD, some repairs may be possible'with the unit at power. The 24_ hour Completion Time is reasonable to repair inoperable ASD lines, based on the availability of the Condenser Steam Dump System and MSSVs, and the low probability of.an event
- occurring durir.g this period that would require the ASD lines.
l --(ZNSERT 2) y A /.1 and d.2 9 If the. required ASD line(s) cannot be , restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LC0_ does not apply. To achieve this: status,'.
. the unit must be'placed in at least MODE 3 within 6 hours,Eand in MODE 4 within 18 hours. The allowed Completion Times are reasonable, based on operating experience. to reach the required ~
unit' conditions from full power conditions in an orderly manner: and without challenging unit systems. R
- SURVEILLANCE. SR3.7.4.1 REQUIREMENTS
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To perform'a controlled cooldown of the RCS, the ASDs must be- _
"able!to be opened remotely and thro'11ed through their full range cThis SR ensures that the AE are tested through a full control cycle. as' described in the Inservice' Test Program.
The conditionsLthat best. verify the operability of the ASDs is
#. . with the manual isolation valve open and nominal ' steam line
$ operating pressure and temperature. The ASDs are designed such that steam line: pressure acts on top of the valve. plug When the valve is required to save to the open position the actuator must act against steam line pressure. For this surveillance-requirement to best verify the_ operational readiness of the ASDs, it should be performed at. nominal SG' operating temperature and pressure, which is in the upper portion of MODE 3 (Ref. 5).
m e :Use o'f an ASD during a unit cooldown may satisfy this c . requirement. Operating experience has shown that these Tcompor,ents usually pass the Surveillance 'when performed at the ' (continued) -<
-CALLWAYiPLANT ITS - BASES B 3.7 21 5/15/97
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.a INSERT 7s D.1 and D.2 Requiring a 30 day limit for restoring an ASD valve to OPERABLE status from inoperable, due to excessive seat leakage from the valve, provides assurance that the required number of ASDs_will be available for plant cooldown. This action limits the period in when a manual isolation valve is closed due to excessive seat leakage of the ASD arid minimizes the delay associated with manually opening a closed manual isolation valve (due to excessive seat leakage of the ASD. Required ACTIONS D.1 and D.2 are modified by a Note indicating that LCO 3.0.4 does not apply.
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. SURVEILLANCE SR 3.7.4.1 (continued) )'
REQUIREMENTS required Inservice Testing Program Frequency. . The Frequency is acceptable from a reliability standpoint. This Surveillance Requirement is modified by a Note that allows entry into and operation in MODE 3 prior to performing the SR. This allows a delay of testing until MODE 3. to establish conditions consistent with those under which acceptance criterion was generated (Ref. 5). SR 3.7.4.2 The function of the manual isolation valve is to isolate a failed open or leaking ASD. Cycling the manual isolation valve both closed and open demonstrates its capability to perform this function. Performance of inservice testing or use of the manual isolation valve during unit cooldown may satisfy this ! requirement. Operating' experience has shown that these.
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components usually pass the Surveillance when performed in ,
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accordance with the Inservice Testing Program Frequency. The Frequency is acceptable from a reliability standpoint. U l REFERENCES- 1. . FSAR. Section 10.3 Main Steam Supply Syston:.
- 2. FSAR Chapter 15.2. Decrease-in Heat Removal by the Secondary System.
- 3. FSAR. Section 15.6.3. Steam Generator Tube Failure.
.4 . FSAR. Section 9.3.1. Compressed Air System.
- 5. Operating License Amendments 45 and 59.
CALLAWAY PLANT-ITS - BASES B 3.7 22 5/15/97
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