ML20237B639
| ML20237B639 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 07/30/1998 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20237B634 | List: |
| References | |
| NUDOCS 9808190121 | |
| Download: ML20237B639 (130) | |
Text
{{#Wiki_filter:,__ _ s L Accumulators 3.5.1 p: , '3,5 EMERGENCY CORE COOLING. SYSTEMS'(ECCS) () L 3.5.1" accumulators-iLC0J3.5.1;- Four,ECCS accumulators shall be OPERABLE.
, m,'-
APPLICABILITY: MODES 1 and 2, c w 5.h[F to;-
~~'#
MODE 3 with Reactor Coolant System -(RCS) pressure
~
> 1000 psig.
,y ACTIONS CONDITION.. REQUIRED' ACTION: COMPLETION TIME I s 1A. One' accumulator . ' A'; 1: -Restore boron: 72 hours inoperable due'to . concentration to
> boron concentration within. limits. .
not within; limits. n
- 18. One' accumulator B.1~ Restore accumulator' 1 hour.
inoperable for-reasons to OPERABLE' status. O. '
'other'than Condition A.-
x
-C. ; Required Action'and1 C.1 :Be in MODE 3. 6 hours
. associated Completion
~ ,
iTime of Condition A - ANQ Lor'.Bnot. met u - C.2 Reduce:RCS pressure- '12 hours-to s 1000 psig.
' ' 1Dc Two or more D .1 - Enter-LCO 3.0.3. Immediately
- j :
. Accumulators-iinoperable,
~
7& ~ , . ( us k" 9808190121 980730 [' ' PDR ADOCK 05000454 BYRON /-f0 NITS 1;&2 3.5.1 6/22/98RevisionII
- p. $
i it) ~ - 1
Accumulators l 3.5.1 i i
/] 'w ]
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 Verify each accumulator isolation valve is 12 hours fully open. l l SR 3.5.1.2 Verify borated water level in each 12 hours accumulator is a 31% and 5 63%. l l I SR 3.5.1.3 Verify nitrogen cover pressure in each 12 hours accumulator is a 602 psig and s 647 psig. 1 ! SR 3.5.1.4 Verify boron concentration in each 31 days accumulator is a 2200 ppm and s 2400 ppm. ' hr SR 3.5.1.5 NOTE Only required to be performed for affected ' accumulators after each solution volume increase of a 10% of indicated level that l is not the result of addition from the refueling water storage tank containing a boron concentration a 2200 ppm and 5 2400 ppm. ' l 4
~~
-Verify boron concentration in each Once within accumulator is a 2200 ppm and s 2400 ppm. 6 hours l
SR 3.5.1.6 Verify power is removed from each 31 days accumulator isolation valve operator. O (_/ l BYRON - UNITS 1 & 2 3.5.1-2 7/9/98 Revision A
ECCS-Operating 3.5.2 l l (~ 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)
~3.5.2 ECCS-Operating i
LCO 3.5.2 Two ECCS trains shall be OPERABLE.
- . -- NOTES---- ---
l
- 1. In MODE 3. both Safety Injection (SI) pump flow paths and a portion of both Residual Heat Removal (RHR) pump flow paths may be isolated by closing the isolation valves for up to 2 hours to perform pressure isolation i l valve testing per SR 3.4.14.1.
- 2. In MODE 3. a Jortion of both Residual' Heat Removal (RHR) ,
pump _ flow patas may be isolated by closing the isolation ! valves for up to 2 hours to perform pressure isolation l l valve testing per SR 3.4.14.1, provided an alternate ! l_ means of cold leg injection is available for each isolated flow path. l l 1 l APPLICABILITY: MODES 1. 2. and 3. l l_ ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME b 'A. One train-inoperable A.1 Restore train to -7 days l . OPERABLE status. .
- B. Two' trains inoperable. B.1 Restore one train to 72 hours OPERABLE status. -
'AND At least 100% of the
- E ECCS flow equivalent to a single OPERABLE ECCS train available.
l (continued) n V-
-BYRON UNITS 1 & 2 3.5.2-1 7/9/98Revisiond' L
L L.
l ECCS -Operating l , 3.5.2 ACTIONS (continued)- CONDITION REQUIRED ACTION COMPLETION TIME l
- l. .C. Required Action and C.1 Be in MODE 3. 6 hours 3
. associated Completion j Time not met. MD l
C.2 Be in MODE 4. 12 hours 1 i i O BYRON - UNITS 1 & 2 3.5.2-2 7/9/98 Revision A t l
! ECCS -Operating i 3.5.2
/~)
i(> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the 12 hours listed position with power to the valve operator removed. Number Position Function MOV SI8806 Open Suction to SI Pumps MOV SI8835 Open SI Pump Discharge to Reactor Coolant System (RCS) Cold Legs MOV SI8813 Open SI Pump Recircul.ation to the Refueling Water Storage Tank MOV SI8809A Open RHR Pump Discharge to RCS Cold Legs
) MOV SI88098 Open RHRPumboldLegsDischarge to RCS MOV SI8840 Closed RHR Pum) Discharge to RCS iot Legs MOV SI8802A Closed SI Pump Discharge to RCS Hot Legs MOV SI8802B Closed S1 Pump Discharge to RCS Hot Legs SR 3.5.2.2 Verify each ECCS manual, power operated, 31 days and automatic valve in the flow path, that is not locked. sealed, or otherwise secured in position, is in the correct position.
l l l SR 3.5.2.3 Verify ECCS piping is full of water. 31 days j \ (continued) l BYRON - UNITS 1 & 2 3.5.2-3 7/9/98 Revision A 1 l l i
ECCS - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued) (g~T l SURVEILLANCE FREQUENCY l SR 3.5.2.4 Verify each ECCS pump's developed head at In accordance the test flow point is greater than or with the l equal to the required developed head. Inservice ! Testing Program l SR 3.5.2.5 Verify each ECCS automatic valve in the 18 months flow path that is not locked, sealed, or otherwise secured in position, actuates to i the correct position on an actual or simulated actuation signal.
'SR 3.5.2.6 Verify each ECCS pump starts automatically 18 months on an actual or simulated actuation signal.
SR 3.5.2.7 Verify for each ECCS throttle valve listed V) ( below, each position stop is in the correct 18 months position. Valve Number Valve Function SI8810 A.B.C.D Centrifugal Charging System ; SI8822 A.B.C.D SI_ System (Cold Leg)
~SI8816 A.B.C.D SI System (Hot Leg)
SR 3.5.2.8 Verify, by visual inspection, each ECCS 18 months train containment sump suction inlet is not restricted by debris and the suction inlet l screens show no evidence of structural distress or abnormal corrosion. ; O 1 G . BYRON - UNITS 1 & 2 3.5.2-4 7/9/98 Revision A
L ECCS - Shutdown L 3.5.3
~
3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.3 ECCS'- Shutdown [ LCO 3.5.3 One ECCS train shall be OPERABLE. l 1 l
----NOTE --
I A Residual Heat Removal (RHR) train may be considered ' OPERABLE during alignment and operation for decay heat ' removal. if capable of being manually realigned to the ECCS mode of operation, t
-)
APPLICABILITY: MODE 4.
- ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME J
l A. Required ECCS RHR A.1 Initiate action to Immediately A subsystem inoperable. restore required ECCS U RHR subsystem to OPERABLE status. 4 B. . Required ECCS B.1 Restore required ECCS I hour centrifugal charging centrifugal charging subsystem inoperable. subsystem to OPERABLE status. ! i
~C. Require'd Action and C.'1 Be in MODE 5. 24 hours associated Completion
. Time of-Condition B-not met.
i O '
' BYRON - UNITS 1 & 2 3.5.3-1 7/9/98 Revision A
__m.__________.___._m.___.__._E. 2_ _ , _ _ _ _ _ . . _ _
l l ECCS - Shutdown i 3.5.3 f] O SURVEILLANCE REQUIREMENTS
)
SURVEILLANCE FREQUENCY I SR 3.5.3.1 The following SRs are applicable for all In accordance equipment required to be OPERABLE: with applicable , SRs { SR 3.5.2.1 SR 3.5.2.7 SR 3.5.2.3 SR 3.5.2.8 SR 3.5.2.4 l l l l l f\ C/ i v) BYRON - UNITS 1 & 2 3.5.3-2 7/9/98 Revision A
RWST' l 3.5.4 l f
/ 3.5 _ EMERGENCY CORE COOLING-SYSTEMS (ECCS)
. 3.5.4 Refueling Water Storage. Tank-(RWST) L LC0 3.5.4 The RWST shall be OPERABLE. l APPLICABILITY: MODES 1, 2,-3 and 4. i ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME t b A, 'RWST boron A.1 Restore RWST to
~
8 hours
~
concentration not OPERABLE status. [. vithin limits. l' 18 RWST borated water
- - temperature not within l
- / ~ limits.
?
l
- B. RWST inoperable for B.1 Restore RWST to 1 hour l~ reasons other than OPERABLE status.
L Condition A. i
' ,' C . Required Action and .C.1- Be mi MODE 3. 6 hours )
. associated Completion ;
-Time not met. AND :
1 C.2 Be in MODE 5. 36 hours i y . L 1 L(D
- BYRONi- UNITS 1 & 2- 3.5.4-1 7/9/98RevisionN i:
~
RWST
. 3.5.4 (7 SURVEILLANCE REQUIREMENTS V
l SURVEILLANCE FREQUENCY l I SR 3.5.4.1 NOTE Only required to be performed when ambient air temperature is < 35 F or > 100 F. Verify RWST borated water temperatu're is 24 hours a 35 F and s 100 F. SR 3.5.4.2 NOTE Only required to be performed when ambient air temperature is < 35 F. Verify RWST vent path temperature is 24 hours a 35 F. O
\_/
SR 3.5.4.3 Verify RWET borated water level is a 89%. 7 days SR 3.5.4.4 Verify RWST boron coricentration is 7 days a 2300 ppm and s 2500 ppm.
/~l V
BYRON - UNITS 1 & 2 3.5.4-2 7/9/98 Revision A l l
I L > Seal Injection Flow 3.5.5 l V (%) 3 13.5. EMERGENCY CORE COOLING SYSTEMS (ECCS) [ 3.5.5- Seal Injection Flow l LC0 '3.5.5. Reactor coolant pump seal injection flow shall be within the ! limits of Figure 3.5.5-1. APPLICABILITY: MODES 1. 2, and 3. L ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Seal injection flow A.1 Adjust manual seal 4 hours not within limit, injection. throttle valves to give a_ flow within the limits of i Figure'3.5.5-1. i B ,- Required Action and , ' ' B.1 Be in MODE 3. 6 hours
- associated Completion Time not met. AND B.2 .Be in MODE 4, 12 hours t
Y ?O ; BYRON-USITS1&2 3.5.5-1 7/9/98 Revision A I i l: , i 1_ _ _ _____ .._ _ _ _ _ . _ _
Seal Injection Flow 3.5.5 l ( SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY ! SR 3. 5 '. 5.1 NOTE --
- j. Not required to be performed until 4 hours t
after the Reactor Coolant System pressure i stabilizes at a 2215 psig and 5 2255 psig. l t. ! Verify manual seal injection throttle 31 days valves are adjusted to.give a flow within the limits of Figure 3.5.5-1.
~
\ . O f d l BYRON - UNITS.1,& 2 3.5.5-2 7/9/98 Revision A r
Seal Injection Flow 3.5.5 O o .- _ _ _ . _ _ _ . . _ _ ___ V(~'N j ", 9 . __ _ . _ . _ _ _ . ._ .._._ f:
,,,,y-
* , a,
. 160.30, 225)
~
nw ec. .wvrcervvrc. . vvvs , A,,$en$aN
%,q,7'r^7eceggA. I 3 x .6,6. <a..UW$$.$$^45.$$,$.$$$.$. .$,$'
5,f
,Q% Y"x s
d 20 0 -- - ['O'D{pu g'fy'xYxS[Q( r * " " . *^xXxj'Q/
%jy'YQQ'x*Q' X
Y> f h(4 - 4;psg<<4, exMQ'Q*.4 (55'9i.I ' DO) z
-x
>y 6
#w >y. owwv %v
/x ; v/As%Nw 4we x V /
u <
* ,sy> g% :qs gyy;g Z 175 ; ---- --~
4*'*g>f**~N ,
%NW N
- W V;# g"'
' W:h Q ' 9 X Q : 4 X Q } " >l &' N4*/
*a ' ACCEI' TABLE REGION x$ >*4M'
*N '
6 7?
=
.?
n no u_ - neet X Nuhx47xn,y2.z?,g4.
>z. 22:: s.. -
19.28,150) d ( . .. . i 9
, 'xsg:& y gn ,,@> g ,X <;4X<@p' yq, s @e"7M < l p ,y,x .,,s., > 5,1 ' f;s,;7,z?.
e ,-
= 1
; i gn_ t__ y s4f y _ _ _ _ .__ __.___ _ .._
y n ,y ? v ,;'
, x . .
x a. n?x ' 100 - (hv ',I?%- 'b 'h > g .,4 g
- - - - - - - + - - - - - - - -
y 75 f-- }3
, webw 9;- " Q'gf/ - --- -
5 j 21, 63.43) ; (32, 63.13) U.N m m ABE EGm.N () ! -s E 50--- - - - - -- - - --
~ ,
7. u 35 , _. _ _ _ . . _ _ . _ _ . . . _ _ _ _ . _ _ - . . . _ _ . . W
, i ' a 1
. i 3 20 30 40 50 00 70 i SEAL INJECHON FLOW (Gl'.\l)
Figure 3.5.5-1 (page 1 of 1) Seal Injection Flow Limits t o) b BYRON - UNITS 1 & 2 3.5.5-3 7/9/98 Revision A
i Accumulators B 3.5.1 f'N .B 3,.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) O B 3.5.1 Accumulators BASES BACKGROUND The functions of the ECCS accumulators are to supply water to the reactor vessel during the blowdown phase of a Loss Of Coolant Accident (LOCs), to provide inventory to help accomplish the refill phase that follows thereafter. and to provide Reactor Coolant System (RCS) makeup for a small break LOCA. The blowdown phase of a large break LOCA is the initial period of the transient during which the RCS departs from equilibrium conditions, and heat from fission product decay, hot internals, and the vessel continues to be transferred to the reactor coolant. The blowdown phase of the transient ends when the RCS pressure falls to a value approaching that i of the containment atmosphere. i In the refill phase of a LOCA which immediately follows the ! blowdown phase, reactor coolant inventory has vacated the j
- core through steam flashing and ejection out through the 1 (mV) break. The core is essentially in adiabatic heatup. The i balance of accumulator inventory is then available to help l fill voids in the lower plenum and reactor vessel downcomer ;
so as to establish a recovery level at the bottom of the core and ongoing reflood of the core with the addition of Safety Injection (SI) water. The accumulators are pressure vessels partially filled with borated water and pressurized with nitrogen gas. The accumulators are passi,yg components. since no operator or
- control actions are required in order for them to perform their function. Internal accumulator tank pressure is sufficient to discharge the accumulator contents to the RCS.
if RCS pressure decreases below the accumulator pressure. 4 e LJ ' BYRON - UNITS 1 & 2 , B 3.5.1 - 1 6/12/98 Revision A w_______-__-____-___ __ . _ _ _ _ _ _ _ . _ __ _ -_ __ _ _ _ _ _ _ .
Accumulators B 3.5.1 p J BASES BACKGROUND (continued) Each accumulator is piped into an RCS cold leg via an accumulator line and is-isolated from the RCS by a motor o)erated isolation valve and two check valves in series. T1e motor operated isolation valves are interlocked by P-11 with the pressurizer pressure measurement channels to. ensure that the valves will automatically open as RCS pressure j increases to above the permissive circuit P-11 setpoint. This interlock also prevents inadvertent closure of the valves during normal operation prior to an accident. The valves will automatically open, however, as a result of an ' SI signal. These features ensure that the valves meet the requirements of the Institute of Electrical and Electronic Engineers (IEEE) Standard 279-1971 (Ref. 1) for "o)erating bypasses" and that the accumulators will be availaale for injection without reliance on operator action. The acomulator size, watcr volume, and nitrogen cover pressure are selected so that three of the four a' accumulators are sufficient to partially cover the core before significant clad melting or zirconium water reaction can p occur following a LOCA. The need to ensure that three g accumulators are adequate for this function is consistent with the LOCA assumption that the entire contents of one accumulator will be lost via the RCS pipe break during the blowdown phase of the LOCA. APPLICABLE The accumulators are assumed OPERABLE in both the large and >
. SAFETY ANALYSES small break LOCA analyses at full power (Refs. 2 and 3).
These are the Design Basis Accidents (DBAs) that establish
. the acceptance limits Tor the accumulators. Reference to the analyses for these DBAs is used to assess changes in the accumulators as they relate to the acceptance 1.imits.
1 I e V
' BYRON - UNITS 1 & 2 B 3.5.1 - 2 6/12/98Revisiond I
Accumulators _, B 3.5.1 BASES APPLICABLE SAFETY ANALYSES (continued) In performing the LOCA calculations, conservative assumptions are made concerning the availability of ECCS flow. In the early stages of a LOCA, with or without a loss of offsite power.'the accumulators provide the sole source of makeup water to the RCS. The assumption of loss of offsite power is required by regulations and conservatively 4 imposes a delay wherein the ECCS ' pumps cannot deliver flow 1 until the-emergency diesel generators start, come to rated speed, and go through their timed loading sequence. In cold leg break scenarios the entire contents of one accumulator J are assumed to be lost through the break. The limiting large break LOCA is a double ended guillotine break at the discharge of the reactor coolant pump. During this event, the accumulators discharge to the RCS as soon as y RCS pressure decreases to below accumulator pressure. As a conservative estimate, no credit is taken for ECCS pump l flow until an effective delay has elapsed. This delay p accounts for the diesels starting and the pumps being loaded and delivering full flow. The delay time is conservatively set with an additional 2 seconds to account for SI signal L Qq generation. During this time. the accumulators are analyzed E as providing the sole source of emergency core cooling. No i operator action is assumed during the blowdown stage of a l large break LOCA. r The worst case small break LOCA analyses also assume a time delay before pumped flow reaches the core. For the larger range of small breaks. the rate of blowdown is such that the t- increase in fuel clad temperature is terminated solely by ! Jthe accumulators, wittLpumped flow then providing continued
- cooling. As break size decreases, the accumulators and centrifugal. charging pumps both play a part in terminating l the rise in clad temperature.. As break size continues to decrease, the role of .the accumulators continues to decrease until they are not required and the centrifugal charging
. pumps become solely responsible for te:minating the temperature increase.
t
.l O . 1
, BYRON - UNITS 1 &.2 B 3.5.1 - 3 6/12/98 Revision A
_ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ - - - - -- - --]
l Accumulators l B-3.5.1 O BASES V APPLICABLE SAFETY ANAL /SES (continued) i This LCO helps to ensure that the following acceptance 1 i criteria established for the ECCS by 10 CFR 50.46 (Ref. 4) l will be met following a LOCA:
- a. Maximum fuel . element cladding temperature is 5 2200 F:
. I
- b. Maximum cladding oxidation is 5 0.17 times the total i cladding thickness before oxidation: {
i
- c. Maximum hydrogen generation from a zirconium water i reaction is s 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react; and
- d. Core is maintained in a coolable geometry.
Since the accumulators discharge during the blowdown phase of a LOCA, they do not contribute to the long term cooling requirements of 10 CFR 50.46. q For both the large and small break LOCA analyses, a nominal e V i contained accumulator water volume is used. The contained water volume is the same as the deliverable volume for the accumulators, since the accumulators are emptied, once discharged. For small breaks, the peak clad temperature is not sensitive to the accumulator water volume. For large breaks, there are two competing effects regarding accumulator water volume: the amount of water available for injection versus the injection rate. While a larger water volume is a benefit. it leaves a smaller volume of nitrogen gas in the accumulatotyhich results in a slo'wer injection
- rate as the accumulator discharges, resulting in a penalty.
Conversely, while less water volume is a penalty, it will be injected at a higher rate due to the larger nitrogen gas volume. Since the range of accumulator volumes is relatively small along with the resulting effect on peak cladding temperature, a nominal water volume is.used. The analysis conservatively ignores the line water volume from the accumulator to the check valve. The safety analysis assumes a nominal water volume of 7106 gallons based on minimum and maximum volumes of 6995 gallons (31% of indicated level) and 7217 gallons (63% of indicated level), respectively. i BYRON - UNITS 1 & 2 B 3.5.1 - 4 6/12/98 Revision A j l
i Accumulators B 3.5.1
)
BASES ! (V~T APPLICABLE SAFETY ANALYSES (continued) I l The minimum boron concentration setpoint is used in the post i LOCA boron concentration calculation. The calculation is performed to assure reactor subtriticality in a post LOCA environment. Of particular interest is the large break LOCA. since no credit is taken for control rod assembly insertion. A reduction in the accumulator minimum boron concentration would produce a subsequent reduction in the available containment sump concentration for post LOCA shutdown and an increase in the maximum sump pH. The maximum boron concentration is used in determining the cold leg to hot leg recirculation. injection switchover time and , minimum sump pH. The large and small break LOCA analyses a're performed at the l minimum nitrogen cover 3ressure, since sensitivity analyses have demonstrated that ligher nitrogen cover pressure results in a computed peak clad temperature benefit. The maximum nitrogen cover pressure limit prevents accumulator relief valve actuation, and ultimately preserves accumulator integrity. The effects on containment mass and energy releases from the
.c)
(' accumulators are accounted for in the appropriate analyses-(Refs. 2 and 3). The accumulators satisfy Criterion 3 of ' 10 CFR 50.36(c)(2)(ii).
.LC0 The LCO establishes the minimum conditions required to ensure that the accumul !
their core cooling safety_ators functionarefollowing available to accomplish a LOCA. Four accumulators are required to ensure that 100% of the ; contents of three of the accumulators will reach the core l during a LOCA. This is consistent with the assumption that the contents of one accumulator spill through the break. If less than three accumulators are injected during the blowdown phase of a LOCA, the ECCS acceptance criteria of 10 CFR 50.46 (Ref. 4) could be violated. O BYRON - UNITS 1 & 2 B 3.5.1 - 5 6/12/98 Revision A
Accumulators B 3.5.1 BASES LC0 (continued) I i For an accumulator to be considered OPERABLE. the isolation valve must be fully open with power removed. a contained volume a 31% and s 63% (6995 gallons to 7217 galluns) with a i boron concentration a 2200 ppm and s 2400 ppm, and a ' nitrogen cover pressure a 602 and s 647 psig, must be met. APPLICABILITY In MODES 1 and 2. and in MODE 3 with RCS pressure ;
> 1000 psig, the accumulator OPERABILITY requirements are l based on full power operation. Although cooling '
requirements decrease as power decreases, the accumulators are still required to provide core cooling as long as elevated RCS pressures and temperatures exist. This LCO is only applicable at pressures > 1000 psig. At pressures s 1000 psig, the rate of RCS blowdown is such that l the ECCS pumps can provide adequate injection to ensure that I peak clad temperature remains below the 10 CFR 50.46 l (Ref. 4) limit of 2200 F. I In MODE 3. with RCS pressure s 1000 psig, and in MODES 4. 5. and 6. the accumulator motor operated isolation valves are fsv) closed to isolate the accumulators from the RCS. This allows RCS cooldown and dearessurization without discharging the accumulators into the RCS or requiring depressurization of the accumulators. L i G BYRON - UNITS 1 & 2 B 3.5.1 - 6 6/12/98 Revision A t
Accumulators B 3.5.1 BAS,ES ACTIONS A.1-If the boron concentration of one accumulator is not within limits, it must be returned to within the. limits within - 72 hours. In this Condition, ability to maintain I subcriticality or minimum boron precipitation time may be reduced. The boron in the accumulators contributes to the assumption that the combined ECCS water in the partially recovered core during the early reflooding phase of a large break LOCA is sufficient to keep that portion of the core subcritical. One accumulator below the minimum boron concentration limit, however, will have no effect on available ECCS water and an insignificant effect on core subcriticality during reflood. Boiling of ECCS water in the core during reflood concentrates boron in the saturated liquid that remains in the core. In addition, current analysis' demonstrates that the accumulators do not discharge following a large main steam line break. Thus. 72 hours is allowed to return the boron concentration to within limits. Bd s If one accumulator is inoperable for a reason other.than boron concentration, the accumulator must be returned to ! o OPERABLE status within 1 hour. In this Condition, the ! required contents-of three accumulators cannot be assumed to reach the core during a LOCA. Due to the severity of the ; consequences should a LOCA occur in these conditions, the ' 1 hour Com the valve,pletion Timethe or restore to open the proper valve. water remove volume or power to nitrogen cover pressure ensures that prompt' action will be taken to ; return the inoperable accumulator to OPERABLE status. The Completion Time minimizgs the potential for exposure of the unit to a LOCA under tTiese conditions. 3 ) i. t O BYRON - UNITS 1 & 2 B 3.5 7 6/12/98 Revision A 1 L:__ _ _ _ _ - - _ _ _ _ - - - _ - - _ - - - - - - - - -
Accumulators
- j. B 3.5.1
' . BASES ACTIONS (continued)
C.1 and C.2 l If the accumulator cannot be returned to OPERABLE status within the associated Com31etion. Time, the unit must be brought to a MODE in whic1 the-LCO does not apply. To achieve this status, the unit must be brought to MODE 3 within 6 hours and RCS pressure reduced to s 1000 psig ! within-12 hours. The allowed Completion Times are L reasonable, based on operating experience, to reach the i recuired unit conditions' from full power conditions in an 1 L orcerly manner and without challenging plant sy' stems. I y } If more than one accumulator is inoperable.' the unit is in a condition outside the accident analyses: therefore.
- LC0 3.0.3 must be' entered.immediately.
1 [- l SURVEILLANCE- SR 3.5.1.'1 ) ly - REQUIREMENTS
- y Each accumulator valve should be verified to be fully open !
L -
'every 12 hours. This verification ensures that the '
accumulators are available for injection and ensures timely discovery if a valve should be less than fully open. If an 1 solation valve is not fully o)en. the rate of injection to the RCS would be reduced. Altlough a motor operated valve i position should not change with power removed, a closed t
~ valve could result in not meeting accident. analyses
. assumptions. This Frequency is considered reasonable in L'
view of other administystive controls that ensure a k
. . mispositioned isolation valve is unlikely.
SR 3.5.1.2 and SR 3.5.1.3 h Every 12 hours, borated water level and nitrogen cover pressure are verified for each accumulator. This Frequency
'is sufficient to ensure adequate injection during a LOCA.
1-Because of: the static design of the accumulator a 12 hour Frequency usually. allows the operator to identify changes t- before limits are reached. Operating experience has shown this Frequency to be appropriate for early detection and correction of off normal trends. BYRON'- UNITS 1.&-2 B 3.5.1:- 8 6/12/98Revisionk'
e 1 ! 1 L
- Accumulators i
, B 3.5.1 l L ,;N BASES V
l , SURVEILLANCE REQUIREMENTS (continued) l
- l. SR 3.5.1.4 The boron concentration should be verified to be within reauired limits for-each accumulator every 31 days since the l static design of the accumulators limits the ways in which !
the concentration can be changed. The 31 day Frequency is l adequate to identify changes that' could occur from mechanisms such as stratification or-inleakage. SR 3.5:1.5 Sampling the affected accumulator within 6 hours after a l 1% volume-increase (nominally 70 gallons or 10% of indicated level) will identify whether inleakage has caused a !. reduction in~ boron concentration to below the required limit. It is not necessary to verify boron concentration of the accumulator after.a 1% volume increase (10% indicatdd level increase) if the added water inventory is from the , Refueling Water Storage Tank (RWST) and the boron l concentration of-the RWST is a 2200 ppm and s 2400 ppm, With the water contained in the RWST within the boron i p concentration ' requirements of the accumulators, any added
- g inventory would not cause the accumulator *s boron concentration to exceed the limits of this LCO.
-With the only indication available to the operators in the-l control room being level. indication in percent, a required accumulator volume increase of 1% or an increase of 10% of indicated level would-require the accumulator to be sampled -
to verify the accumulator boron concentration is within the-limits The safety analysis' assumes a nominal water volume of 7106 gallons based'.oD minimum and maximum volumes of i; - 6995 gallons (31%) and 7217 gallons (63%). respectively. These volumes are also indicated in the specific tank curves j for the SI accumulators. The 10% indicated level increase is considered a conservative indication for a 70 gallon - increase in the accumulator volume requiring an increase in the sampling requirement to verify accumulator boron concentration remains within the specified limits'. L u l l p ( - i L. BYRON - UNITS 1 & 2 B 3.5.1 - 9 6/12/98 Revision A l l
Accumulators B 3.5.1
\
l ! BASES 'L,A)- SURVEILLANCE REQUIREMENTS (continued) SR 3.5.1.6 Verification every 31 cays that power is removed from each accumulator isolation valve o)erator ensures that an active failure could not result in t1e undetected closure of an accumulator motor operated isolation valve. If this were to occur, only two accumulators would be available for ! injection given a single failure coincident with a LOCA. The power to the accumulator motor operated isolation valves , is removed by opening the motor control center breaker and l l tagging it out administratively. Since power is removed d under administrative control, the 31 day Frequency will provide adequate assurance that power is removed. REFERENCES 1. IEEE Standard 279-1971. 1
- 2. UFSAR, Chapter 15. !
g 3. UFSAR, Chapter 6.
^~ 4. 10 CFR 50.46.
l I i l p N BYRON - UNITS 1 & 2 B 3.5.1 - 10 6/12/98 Revision A
ECCS - Operating B 3.5.2 8 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)-
- B 3.5.2 ' ECCS-Operating BASES' BACKGROUND The function of the_ECCS is to 3rovide core cooling and negative reactivity to ensure tlat the reactor core is protected after any of the following accidents:
l' a. Lubs Of Coolant Accident (LOCA), coolant leakage
' greater. than the capability.of the normal charging .
system: L ,
- b. Rod' ejection accident:
- c. Loss of' secondary coolant accident. including f uncontrolled steam release or loss of feedwater: and j f . d. Steam Generator Tuoe Rupture (SGTR).
The addition of negative reactivity is designed primarily for the loss- of secondary coolant accident where primary cooldown could add enough positive reactivity to achieve l criticality and return to-significant power. There 'are.three phases of ECCS operation: injection, cold leg recirculation, and hot leg recirculation. In the injection phase, water is taken from the Refueling Water i Storage Tank (RWST) and injected into the Reactor Coolant System (RCS) through the cold legs. When sufficient water is removed from the RWST to ensure that enough boron has
. -been added to maintain the reactor subcritical and the l:: containment sumps have_.gnough water to supply the required L -
net ~ positive suction head to the ECCS pumps, suction is ! switched to the containment sump for cold leg recirculation. After approximately 8.5 hours, the ECCS flow is shifted to L the hot leg recirculation phase to 3rovide a backflush, l '- which would reduce the boiling in t1e top of the core and L any resulting boron precipitation. Every 24 hours after L initiation of hot leg recirculation, the flow path is - alternated between hot and cold leg recirculation.
~
( 4 BYRON UNITS 1 & 2 B 3.5.2 - 1 6/12/98 Revision A P L___ _ ._ .___ _ _ _ _ . _ _ _ . _ . . _ _ . _ _ _ ___.._m . _ . _ . _ _ _ _ _ _ _ _ _ . _ _ _ . _ _ _ _ _ . _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ __
ECCS - Operating B 3.5.2 t O B^s's BACKGROUND (continued) The ECCS consists of three separate subsystems: centrifugal l charging (high head). Safety Injection (SI) (intermediate head), and Residuai Heat Removal (RHR) (low head).. Each subsystem consists of two redundant. 100% capacity trains. The ECCS accumulators and the RWST are also part of the l ECCS, but are not considered part of an ECCS flow path as l described by this LCO. The ECCS flow paths consist of piping, valves, heat exchangers, and pumps such that water from the RWST can be injected into the RCS following the accidents described in this LCO. The major components of each subsystem are the centrifugal chargirg pumps, the RHR pumis, heat exchangers. i and the SI pumps. Each of the three su) systems consists of two 100% capacity trains that are interconnected and l redundant such that either train is capable of supplying l 100% of the flow required to mitigate the accident l consequences. This interconnecting and redundant subsystem design provides the operators with the ability to utilize components from opposite trains to achieve the required 100% flow to the core. During the injection phase of LOCA recovery, a single suction header supplies water from the RWST to the ECCS pumps. Separate piaing supplies each subsystem and each train within the suasystem. The discharge from the I centrifugal charging pumps combines prior to dividing into four supply lines, each of which feeds the injection line to one RCS cold leg. The discharge from the 51 and RHR pumps divides and feeds an injection line to each of the RCS cold legs. Control valves are set to balance the flow to the RCS. This balance ensures sufficient flow to the core to meet the analysis assumptions following a LOCA in one of the RCS cold legs. For LOCAs that are too small to depressurize the RCS below the shutoff head of the SI pumps, the centrifugal charging pumps supply water until the RCS pressure decreases below the SI pump shutoff head. During this period, the steam generators are used to provide part of the core cooling function. l l [v BYRON - UNITS 1 & 2 B 3.5.2- 2 6/12/98 Revision A L
ECCS - Operating B 3.5.2 BASES l BACKGROUND (continued) During the recirculation phase of LOCA recovery RHR pump suction is transferred to the containment sump. .The RHR pumps then supply the other ECCS pumps. Initially. l recirculation is through the same paths as the injection l 3hase. Subsequently, recirculation alternates injection Jetween the hot and cold legs.
- The centrifugal charging subsystem of the ECCS also
- functions to supply borated water to the reactor core
! following increased heat removal events such as a Main l Steam Line Break (MSLB). The limiting design conditions occur when the negative moderator temperature coefficient is highly negative, such as at the end of each cyc'le. l During low temperature conditions in the RCS, limitations are placed on the maximum number of ECCS pumps that may be OPERABLE. Refer to the Bases for LC0 3.4.12. " Low Temperature Overpressure Protection (LTOP) System." for the l basis of these requirements. The ECCS subsystems are actuated upon receipt of an SI
,- signal. The actuation of safeguard loads is accomplished in
- g)
I a programmed time sequence. If offsite power is available. , the safeguard loads start immediately in the programmed sequence. If offsite power is not available, the Engineered Safety Feature (ESF) buses shed normal operating loads and are connected to the emergency Diesel Generators (DGs). Safeguard loads are then actuated in the programmed time sequence. The time delay associated with diesel starting. ! sequenced loading, and pump starting determines the time l required before pumped flow is available to the core following a LOCA. _ l l The active ECCS components, along with the passive accumulators and the RWST covered in LC0 3.5.1.
" Accumulators." and LC0 3.5.4. " Refueling Water Storage Tank l (RWST)." provide the cooling water necessary to meet GDC 35 l (Ref. 1).
l l 1 j i ! p j ld BYRON - UNITS 1 & 2 B 3.5.2 -3 6/12/98 Revision A i l b-
ECCS - Operating B 3.5.2 l
]v BASES l APPLICABLE The LCO helps to ensure that the following acceptance
_ SAFETY ANALYSES- criteria for the ECCS. established by 10 CFR 50.46 (Ref. 2). i will be met following a LOCA:
- a. Maximum fuel element cladding temperature is s 2200 F:
j b. Maximum cladding oxidation is s 017 times the total l cladding thickness before oxidation:
- c. Maximum hydrogen generation from a zirconium water
- l. reaction is s 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react:
- d. Core is maintained in a coolable geometry: and
- e. Adequate long' term core cooling capability is maintained.
l The LCO also limits the potential for a post trip return to power following an MSLB event and ensures that containment temperature limits are met.
- Each ECCS subsystem is taken credit for in a large break i
LOCA event at full power (Ref. 3). This event establishes the requirement for runout flow for the ECCS pumps, as well as the maximum response time for their actuation. The centrifugal charging pumps and SI pumps are credited in a small break LOCA event. This event establishes the flow and ! . discharge head at the design point for the centrifugal l . charging pumps. The SGTR and MSLB events also credit the ! centrifugal charging pgpps. The OPERABILITY requirements ! . for the ECCS are based [on the following LOCA analysis i assumptions:
- a. A large break LOCA event, with loss of offsite power and a single failure disabling one RHR pump (both l emergency DG trains are assumed to operate due to requirements for modeling full active containment heat removal system operation): and
- b. A small break LOCA event, with a loss of offsite power i and a single. failure disabling one ECCS train.
f3 V BYRON - UNITS 1 & 2 B 3.5.2 - 4 6/12/98Revisionk'
l ECCS - Operating
, B 3.5.2 / BASES APPLICABLE SAFETY ANALYSES (continued) l During the blowdown stage of a LOCA, the RCS depressurizes as primary coolant is ejected through the break into the containment. The nuclear reaction is terminated either by l moderator voiding during large breaks or control rod l insertion for small breaks. Following depressurization, i
emergency cooling water is injected into the cold legs. ! flows into the downcomer, fills the lower plenum, and refloods the core. The effects on containment mass and energy releases are accounted for in appropriate analyses (Refs. 3 and 4). The I LCO ensures that an ECCS train will deliver sufficient water to match boiloff rates soon enough to minimize the consequences of the core being uncovered following a large , LOCA. It also ensures that the centrifugal charging and SI l aumps will deliver sufficient water and boron during a small _0CA to maintain core subcriticality. For smaller LOCAs. the centrifugal charging Jump delivers sufficient fluid to maintain RCS inventory. or a small break LOCA, the steam generators continue to serve as the heat sink, providing part of the required core cooling. l
. The ECCS trains satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
l l LC0 In MODES 1. 2. and 3. two independent (and redundant) ECCS trains are required to ensure that sufficient ECCS flow is available. assuming a single failure affecting either train. Additionally, individual components within the ECCS trains may be called upon to, mitigate the consequences of other
- transients and accidents.
In MODES 1, 2. and 3 an ECCS train consists of a centrifugal charging subsystem, an SI subsystem, and an RHR subsystem. Each train includes the piping._ instruments, and crotrols to ensure an OPERABLE flow path capable of taking i suction from the RWST upon an SI signal and automatically transferring suction to the containment sump. l l l q D l l BYRON - UNITS 1 & 2 B 3.5.2 - 5 6/12/98 Revision A I l
ECCS - Operating
, B 3.5.2 I BASES
( ) LCO (continued) During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to supply p its flow to the RCS hot and cold' legs. The flow path for each train must maintain its designed independence to ensure that no single failure can disable both ECCS trains. l The LCO is modified by two Notes that allow isolation of both SI pump flow paths and a portion of both RHR flow paths for up to 2 hours to perform pressure isolation valve testing per SR 3.4.14.1 during MODE 3. Isolation of the discharge flow paths of both SI pumps may be accom)11shed by closing valve SI8835. Isolation of a portion of t1e discharge flow paths of both RHR pumps may be accomplished by closing either valve SI8809A or SI8809B. With a portion of both RHR flow paths-isolated, an alternate means of cold leg injection must be available for each isolated flow path.
? An alternate means may include: 1) OPERABLE accumulators lW with their isolation valves either closed ~, but energized, or (V Mm open: 2) cold leg injection via the Safet and the SI8821A/B and the SI8835 valves;ory 3) Injection pumps.
cold leg g injection via the Centrifugal Charging pumps and the g SI8801A/B valves. I APPLICABIL'ITY In MODES 1. 2. and 3. the ECCS OPERABILITY requirements for
~ )
.the limiting Design Basis Accident, a large break LOCA, are based on full power operation. Although reduced power would not require the same level of performance, the accident i analysis does not provide for reduced cooling requirements i in the lower MODES. The centrifugal charging pump i
. performance is based on a small break LOCA. which :
. establishes the pump performance curve and has less i dependence on power. The SI pump performance requirements are based on a small break LOCA. MODE 2 and MODE 3 >
requirements are bounded by the MODE 1 analysis. L 77: . V BYRON - UNITS 1 & 2 B 3.5.2 - 6 6/22/98 Revision H i
ECCS -Operating B 3.5.2
/^ BASES L)\
APPLICABILITY (continued) l This LCO is only applicable in MODE '3 and above. Below MODE 3, the SI signal setpoint is manually bypassed by l operator control, and system functional requirements are relaxed as described in LC0 3.5.3, "ECCS-Shutdown." l' In MODES 5 and 6. unit conditions are such that the . probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are l addressed by LCO 3.4.7, "RCS Loops-MODE 5. Loops Filled." and LC0 3.4.8, "RCS Loops-MODE 5, Loops Not Filled." MODE 6 core cooling requirements are addressed by LC0 3.9.5. l " Residual Heat Removal (RHR) and Coolant Circulation-High
- Water Level," and LCO 3.9.6. " Residual Heat Removal (RHR)
! and Coolant Circulation-Low Water Level ." ACTIONS A.1 and B.1 - , With one ECCS train inoperable.100% of the ECCS flow is provided by the remaining OPERABLE ECCS train. Required Action A.1 requires that the inoperable train be restored to ' .h v OPERABLE status within 7 days. The 7 day Completion Time is based on a 3robabilistic risk assessment evaluation (Refs. 6 and-7) whic1 concludes that the Completion Time does not significantly affect the overall probability of core damage. With two ECCS trains inoperable and at least 100% of the i ECCS flow equivalent to a single OPERABLE ECCS train available. Required Action B.1 requires that one train be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is bas
. (Ref. 5) and is a rease_d on an onable NRC time reliability for repair evaluation of many ECCS components.
An ECCS train is inoperable if it is not capable of delivering design flow to the RCS. Individual components are inoperable if they are not capable of performing their desi n function or their required supporting systems are not j avai able. l l l O BYRON - UNITS 1 & 2 B 3.5.2 - 7 6/12/98 Revision A l
ECCS- Operating i B 3.5.2
]
BASES I l ACTIONS (continued) The LCO requires the OPERABILITY of a number of independent i l subsystems. Due to the redundancy of trains and the ' diversity of subsystems, the inoperability of one component in a train does not render the ECCS inccpable of performing , L its function. Neither does the inoperability of two different components. each in a different train, necessarily result in a loss of function for the ECCS. The intent of i these Conditions is to maintain a combination of equipment such that 100% of the ECCS flow equivalent to a single OPERABLE ECCS train remains available. Thus, for 100% of the ECCS flow equivalent to a single OPERABLE ECCS train to remain available, at least one train of each centrifugal charging subsystem, SI subsystem, and RHR subsystem, including an RHR heat exchanger, must be OPERABLE. This allows increased flexibility in unit operations under circumstances when components in opposite trains are inoperable. Reference 8 describes situations in which one component, such as an RHR crossover valve, can disable both ECCS trains. With one or more component (s) inoperable such that l 100% of the flow equivalent to a single OPERABLE ECCS train
- is not available, the facility is in a condition outside the l dr~
accident analysis. Therefore, LCO 3.0.3 must be immediately entered. C.1 and C.2 If the ino)erable trains cannot be returned to OPERABLE status witlin the associated Completion Time, the unit must !
- be brought to a MODE in which the LCO does not apply. To achieve this status, unit must be brought to MODE 3
- within 6 hours and MO 4 within 12 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 plant systems.
l O
;V BYRON - UNITS 1 & 2 B 3.5.2 - 8 6/12/98 Revision A l
u
ECCS - Operating B 3.5.2 9 BASES (J SURVEILLANCE SR 3.5.2.1 REQUIREMENTS Verification of proper motor operated valve position ensures that the injection flow path from the ECCS pumps to the RCS is maintained. Misalignment of these valves could render both ECCS trains inoperable. Securing these valves in position by removal of power ensures that they cannot change position as a result of an active failure or be inadvertently misaligned. These valves are of the type, described in Reference 8. that can disable the function of both ECCS trains and invalidate the accident analyses. A 12 hour Frequency is considered reasonable in view of other administrative controls that will ensure a mispositioned valve is unlikely. SR 3.5.2.2 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 (e.g., the
,q valves listed in SR 3.5.2.1 and SR 3.5.2.7), since these \#
were verified to be in the correct position prior to locking, sealing or securing. A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation. Rather, it involves verification that those valves capable of being mispositioned are in the correct position. The 31 day Frequency is appropriate because the valves are operated under administrative rontrol, s and an improper valve position
- would only affect a single train.. This Frequency has been shown to be acceptable through operating experience.
A Q ' BYRON - UNITS 1 & 2 B 3.5.2 - 9 6/12/98 Revision A l
w? - !' a-ECCS- Operating j B 3.3.2 I' BASES l SURVEILLANCE REQUIREMENTS (continued) SR '3.5.2.3 With the-exception of the operating centrifug'al charging pump, the ECCS pumps are normal.ly in a standby, nonoperating-As such flow. )ath piping has the potential to
' mode.
develop voids and poccets of entrained gases. The system .
.will perform properly, injecting its full capacity into the RCS upon demand. by-maintaining the piping from the ECCS
, :pumpc-to..the RCS full of water. This will also prevent-water hammer pump cavitation..and pumping of noncondensible gas (e.g., air, nitrogen. 'or hydrogen) into the reactor .
.' ? vessel following an SI signal 'or during shutdown cooling.
.This is accom311shed by venting the non-operating ECCS pump casings'and t1e discharge piping high points-(applicable to idle RH-and SI systems only):outside containment to maintain the ECCS piping full'of water In the event'that gas is-
. isolation valve.(SI8809A/present at either RH cold' leg B) vent valve-(SIO58A/B). the three i
L gas traps associated with the ECCS crossover piping will,be
- UT ' inspected to confirm the piaing -is full of water.
~ ' SR 3.5.2.3 requires that the Ri and SI pump casings and '
-discharge piping high pointivent' valves be vented. This 77 V~
L. venting surveillance does not apply to subsystems in communication with operating-systems because the-flows in-i 1 these systems are sufficient to provide confidence. that' water hammer which'could ' occur from voiding would not result in unacceptable' dynamic loads; During shutdown cooling operation. the exclusion:would apply to the operating.RH pump', in addition'to the ECCS piping in communication with the operating pump. j C
- z. For selected; portions of pi the idle CV pump: discharge ping (i.e. . portions 1nvolving piping.-up to the first check
' valve on the pump discharge and miniflow lines, the st.agnant portion of the piping upstream of the SI8801A/B adjacent to the' vent valve 51045, and the piping;at the CV206 valve if
-the B CV pump is idle) the verification that the. piping is :
- filled with water will be. performed by ultrasonic i examination; This examination will provide added assurance e that-the piping is water solid. These methods are- !
,~ consistent with Reference 9. :
1 y ' l
}
-.LBYRON'- UN'ITS 1 &=2. B . 3'. 5'. 2 - 101 6/22/98 Revision H t i
. _ - _. .:2. . - _ - - _ -l_ . --_ _ - _ . _ _ _ - _ - . _ - - - _ - _ - - _ _ - _ _ - _ - - - _ _ _ _ . - - _ - _ _ _ . -.____]
ECCS -Operating B 3.5.2 O (d BASES SURVEILLANCE REQUIREMENTS (continued) The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation. { l SR 3 5.2.4 i Periodic surveillance testing of ECCS pumps to detect gross 3 degradation caused by impeller structural damage or other ' hydraulic component problems is required by SECTION XI of the ASME Code. This type of testing may be accomplished by measuring the pump developed head at only one point of the ; pump characteristic curve. This verifies both that the l measured performance is within an acceptable tolerance of l the original pum) baseline performance and that the ' performance at t1e test flow is greater than or equal to the performance assumed in the plant safety analysis. SRs are i specified in the Inservice Testing Program, which 1 encompasses SECTION XI of the ASME Code. SECTION XI of the i ASME Code provides the activities and Frequencies necessary to satisfy the requirements. p SR 3.5.2.5 and SR 3.5.2.6 These Surveillance demonstrate that each automatic ECCS l valve actuates to the required position cn an actual or simulated SI signal (a coincident RWST Level Low-Low signal is required to open the containment sump isolation valves), and that each ECCS pump starts on receipt of an actual or simulated SI signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required Josition under administrative controls. The 18 month requency is pased on the need to perform these Surveillance under the conditions that apply during a unit outage and the potential for an unplanned unit transient if the Surveillance were performed with the reactor at power. The 18 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic is tested as part of ESF Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program. l (U) BYRON - UNITS 1 & 2 , B 3.5.2 - 11 6/12/98 Revision A
ECCS -Operating B 3.5.2 (] BASES SURVEILLANCE REQUIREMENTS (continued) I SR 3.5.2.7 Realignment of valves in the flow path on an SI signal is l necessary for proper ECCS performance. These valves have mechanical stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold '! legs receive at least the required minimum flow. The !
-18 month Frequency is based on the same reasons as those '
stated in SR 3,5.2.5 and SR 3.5.2.6. SR 3.5.2.8 Periodic inspections of the containment sump suction inlet ensure that it is unrestricted and stays in proper. operating 4
. condition. The 18 month Frecuency is based on the need to l perform this Surveillance uncer the conditions that a) ply 1 during a unit outage, on the need to have access to t7e l location, and because of the potential for an unplanned transient if the Surveillance were performed with'the reactor at power. This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed
- q by operating experience.
V ; I I p V BYRON - UNITS'1 & 2 8 3.5.2 - 12 6/12/98 Revision A-L
._.s
1 ECCS -Operating . B 3.5.2
~
. BASES; k
L"()! . REFERENCES - 1.-
-10 CFR 50, Appendix A, GDC 35.-
2, 10 CFR 50.46.
>3~. UFSAR. Section 15.6.5.
2L .UFSAR.: Section 6' 2.1. 5- . NRC Memorandum tb V.. Stello, Jr., from R. L. Baer',
" Recommended Interim Revisions to LCOs for ECCS
< > Components." December.1,.197.5. .
t
- 6. : Byron Generating. Station Limiting Conditions'for Operation Relaxation Program, dated April 1984.
- 7. WCAP-10526l " Limiting Conditions for_0peration-Relaxation Program."
- 8. NUREG-0876.." Safety Evaluation Report'Related to-Operation of' Byron Station, Units-1 and 2."-
February 1982.
- 9. Safety Evaluation Report, dated January. 30.1998
. associated with-Byron Technical Specification q
; Amendment No. 100.
,V q
)
I J i
/
.4 -
- r~c -
h Lk- - BYRON -. UNITS 1 & 2: B 3.5.2- 13 6/22/98 Revision H B l I L' 4
l - ECCS -Shutdown
. B 3.5.3 f's G
B 3.5 EMERGENCY CORE-COOLING SYSTEMS (ECCS) B 3.5.3 ECCS - Shutdown BASES BACKGROUND The Background section for Bases 3.5.2. "ECCS-Operating." is applicable to these Bases, with the following modifications. In MODE 4. the required ECCS train consists of two separate subsystems: centrifugal charging (high head) and Residual Heat Removal (RHR) (low head). The ECCS flow paths consist of piping valves. heat exchangers, and pumps such that water from the Refueling Water Storage Tank (RWST) can be injected into the Reactor Coolant System (RCS) following the accidents described in Bases 3.5.2. 4 APPLICABLE The Applicable Safety Analyses section of Bases 3.5.2 also
,- SAFETY ANALYSES applies to this Bases section.
C Due to the stable conditions associated with operation in MODE 4 and the reduced probability of occurrence of a Design Basis Accident (DBA), t1e ECCS operational requirements are reduced. It is understood in these reductions that certain automatic Safety Injection (SI) actuation is not available. In this' MODE, sufficient time exists for manual actuation of the required ECCS to mitigate the consequences of a DBA. Only one train of ECCS is required for MODE 4. This , - requirement dictates tfIat single failures are not considered during this MODE of operation. The ECCS trains satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii). l O V BYRON - UNITS 1 & 2 B 3.5.3 - 1 6/12/98 Revision A i l _ _ _ _ _ __ - _ - - _ _ - - _ - _
ECCS - Shutdown B 3.5.3 BASES i LCO In MODE 4. one of the two independent (and redundant) ECCS trains is required to be OPERABLE to ensure that sufficient ECCS flow is available to the core following a DBA. In MODE 4. an ECCS train consists of a centrifugal charging subsystem and an RHR subsystem. Each train includes the piping instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST and transferring suction to the containment sump. During an event requiring ECCS actuation. a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to deliver its flow to the RCS hot and cold. legs. The LC0 is modified by a Note that allows an RHR train to be considered OPERABLE during alignment and operation for decay heat removal if capable of being manually realigned (remote or local) to the ECCS mode of operation and not otherwise n inoperable. This allows operation in the RHR mode during tg MODE 4. APPLICABILITY In MODES 1. 2 and 3. the OPERABILITY requirements for ECCS are covered by LC0 3.5.2. In MODE 4 with RCS temperature below 350 F. one OPERABLE ECCS train is acceptable without single failure consideration, on theJ,b sis of the stable reactivity of the reactor and-the limited core cooling requirements. In MODES 5 and 6. unit conditions are such that the probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are addressed by LCO 3.4.7. "RCS Loops-MODE 5. Loops Filled." and LC0 3.4.8. "RCS Loops-MODE 5. Loops Not Filled." MODE 6 core cooling requirements are addressed by LCO 3.9.5.
" Residual Heat Removal (RHR) and Coolant Circulation-High Water Level ." and LCO 3.9.6. " Residual Heat Removal (RHR) i and Coolant Circulation-Low Water Level."
BYRON - UNITS 1 & 2 B 3.5.3 - 2 6/12/98 Revision A , i L_________________________ _ _ . . _ _ _ . __ . _ _ _ _ _ _
.j
ECCS - Shutdown B 3.5.3 1 O BASES V ACTIONS A.1 With no ECCS RHR subsystem OPERABLE the unit is not l prepared.to respond to a loss of coolant accident or to ' continue a cooldown using the RHR pumps and heat exchangers. The Completion Time of immediately to initiate actions that ! would restore at least one ECCS RHR subsystem to OPERABLE ' status ensures that prompt action is taken to restore the required cooling capacity. Normally, in MODE 4. reactor ) decay heat is removed from the RCS by an RHR loop. If no i RHR loop is OPERABLE for this function, reactor decay heat must be removed by some alternate method such as use of the steam generators. The alternate means of heat removal must continue until the inoperable RHR loop components can be l restored to operation so that decay heat removal is j continuous. With both RHR pumps and heat exchangers inoperable. it would l be unwise to require the unit to go to MODE 5. where the i only available heat removal system is the RHR. Therefore. l the appropriate action is to initiate measures to restore 1
. one ECCS RHR subsystem and to continue the actions until the subsystem is restored to OPERABLE status.
t
~
fL1 With no ECCS centrifugal charging subsystem OPERABLE. due to ! the inoperability of the centrifugal charging pump or flow : ' path from the RWST. the unit is not prepared to provide high ! pressure response to Design Basis Events requiring SI. The l 1 hour Completion Time to restore at least one centrifugal charging subsystem to OPERABLE status ensures that prompt action is taken to prqyjde the required cooling ca)acity or L to initiate actions to place the unit in MODE 5. w1ere an ECCS train is not required. l l C.1 When the Required Actions of Condition B cannot be completed within the required Completion Time, a controlled shutdown should be initiated. Twenty-four hours is a reasonable time, based on operating experience, to reach MODE 5 in an orderly manner and without challenging plant' systems or I operators. ' O V . BYRON - UNITS 1 & 2 B 3.5.3 - 3 6/12/98 Revision A
. j ECCS - Shutdown B 3.5.3
') BASES L) .
i SURVEILLANCE SR 3.5.3,1 REQUIREMENTS-The applicable Surveillance descriptions from Bases 3.5.2
~
apply. .
-REFERENCES The-applicable references from Bases 3.5.2 apply l
t l l LO 1 l l
.- I 1
l 1 l l I I L I
/"N., l N.]
t BYRON ' UNITS l'& 2- B 3.5.3 - 4 6/12/98 Revision A
(- RWST B 3.5.4 B 3,.5 . EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.4 Refueling Water Storage Tank (RWST) , BASES BACKGROUND The.RWST supplies borated water to the Chemical and Volume Control System (CVCS) during abnormal operating conditions. to the refueling pool during refueling, and to the ECCS and I t the Containment Spray System during accident conditions. I [ The RWST-supplies both trains of the ECCS and the l ! Containment Spray System through separate, redundant. supply j i headers during the injection phase of a Loss Of Coolant Accident (LOCA) recovery. A motor operated isolation valve is provided in each header to isolate'the RWST from the ECCS l once the system has been transferred to the recirculation ; mode. The recirculation mode is entered when pump suction i is transferred'to the containment sump following receipt of l L the RWST Level-Low Low (LO-2) signal. Use of a single RWST l [ to supply both trains of the ECCS and Containmen.t Spray l' -System is acceptable since the RWST is a 3assive component, y and passive failures are not required to 3e assumed to occur coincidentally with Design Basis Events, L \- J The switchover from normal o)eration to the injection phase of ~ECCS operation requires clanging centrifugal charging pump suction from the CVCS Volume Control Tank (VCT. to the-RWST through the use of isolation valves. Each set of : L isolation valves is interlocked so that the VCT isolation ! valves will begin to close once the RWST isolation valves L are fully open. Since the VCT is under pressure, the preferred pum i
-is isolated. p This suction will_will result be from in a the delay VCT until the tank in obtaining the ,
L ~ RWST borated water. The effects of this delay are discussed ' L in the Applicable Safety Analyses section of these Bases l t-During normal operation in MODES 1, 2. and 3 the Safety , Injection (SI) and Residual Heat Removal (RHR) pumps are l l aligned to take suction from the RWST. fi L The.ECCS pumps are provided with recirculation lines that n ensure each pump can raintain minimum flow requirements when ! operating at or near shvoff head conditions. ! i F l i.! h v l BYRON - UNITS 1 & 2'- : B 3.5.4 - 1 6/12/98 Revision A l 4 l} L-_i-- _ - - _ - - - - - - - _ - - - - - _ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --------- -- ----
l RWST B 3.5.4 i ' /7 BASES l V BACKGROUND-(continued) When the suction for the ECCS and Containment Spray System pumps is transferred to the containment sump. the RWST flow paths must be isolated to prevent a release of the containment sump contents to the RWST which could result in a release of contaminants to the atmosphere and the eventual loss of suction head for the ECCS pumps. This LC0 ensures that:
- a. The RWST contains sufficient borated water to support the ECCS during the injection phase;
- b. Sufficient water volume exists in the containment sump to support continued operation of the ECCS and Containment Spray System pumps at the time of transfer to the recirculation mode of cooling:
- c. The reactor remains subcritical following a.LOCA: and
- d. The RWST contains a sufficient boron concentration to ensure that negative reactivity is available to limit
, q the subsequent return to power following a Main Steam Line Break (MSLB). Insufficient water in the RWST could result in insufficient cooling capacity when the transfer to the recirculation mode occurs. Impro)er boron concentrations could result in a reduction of slutdown margin or excessive boric acid precipitation in the core following the LOCA. In addition.
, improper boron concentrations could adversely affect the pH
. of the sump following the LOCA which can adversely impact iodineconcentrationsforoffsitedoses,stresscorrosion
- cracking of equipment inside containment, and hydrogen production. Finally, improper boron concentrations could adversely affect the pH of the containment spray which can also adversely impact iodine concentrations for offsite doses (Ref. 1).
l l l I 2x. v BYRON - UNITS 1 & 2 B 3.5.4 - 2 6/12/98Revisiond o----_-----_------------_-__-__--.----- - -- - . - - - - - - _ - - - - - - . - - - - - - - - . - - _ - - - - - - _ - - . - - - . - - - - - - - - - - - - - - _ - - . - - - - - - - . _ - - _ - - - - - _ - - - - - - -
RWST
, B 3.5.4 O BASES V
APPLICABLE During accident conditions. the RWST provides a source of I SAFETY ANALYSES borated water to the ECCS and Containment Spray System j pumps. As such, it provides containment cooling and ' depressurization, core cooling, and replacement inventory and is a source of negative reactivity for reactor shutdown (Refs. 2 and 3). The design basis transients and applicable safety analyses concerning each of these systems are discussed in the Applicable Safety Analyses section of B 3.5.2. "ECCS-Operating": B 3.5.3. "ECCS-Shutdown", and B 3.6.6. " Containment Spray and Cooling Systems." These analyses are used to assess changes to the RWST in order to evaluate their effects in relation to the acceptance limits in the analyses. The RWST must also meet volume, boron concentration, and j temperature requirements for non-LOCA events. The volume is ; not an explicit assumption in non-LOCA events since the ; required volume is a small fraction of the available volume. The deliverable volume limit is set by the LOCA and containment analyses. For the RWST, the deliverable volume j is different from the total volume contained since, due to ; the design of the tank, more water can be contained than can l be delivered. The minimum boron concentration is an l explicit assumption in the MSLB_ analysis and ensures that j negative reactivity is available to limit the subsequent ! return to power following an MSLB. The minimum boron concentration limit is also an important assumption in l ensuring the reactor remains subcritical following a LOCA. l The maximum boron concentration is an explicit assumption in l the inadvertent ECCS actuation analysis, although it is ' typically a nonlimiting event and the results are very insensitive to boron concentrations. The maximum temperature ensures th 3rovided from the RWST during theatup he,atphase the amount of cooling of a feedline 3reak is consistent with safety analysis assumptions: the minimum is an assumption in both the MSLB and inadvertent ECCS actuation analyses, althoagh the inadvertent -ECCS actuation event is typically nonlimiting, i BYRON - UNITS 1 & 2 B 3.5.4 - 3 6/12/98 Revision A l _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____-
RWST 4 B 3.5.4 BASES APPLICABLE SAFETY ANALYSES (continued) The MSLB analysis has considered a delay associated with the i interlock between the VCT and RWST isolation valves, and the ' results show that the departure from nucleate boiling design basis is met. The delay has been established as 27 seconds, with offsite power available, or 37 seconds without offsite power. This response time includes 2 seconds for . 4 electronics delay, a 15 second stroke time for the RWST ' valves., and a 10 second stroke time for the VCT valves. For a large break LOCA analysis, the lower boron concentration limit of 2300 ppm and a conservative calculation of the minimum RWST volume between the low level setpoint and the low low level setpoint are used to compute the post LOCA sump boron concentration necessary to assure subcriticality. The large break LOCA is the limiting case since the safety analysis assumes that all control rods are out of the core. The containment analysis and the calculation of the minimum post-LOCA sump pH also use the minimum water volume limit to determine a minimum available RWST volume for calculating the time until recirculation for safety injection and p) (~ containment spray. analysis, which ensures sufficient Net Positive Suction Head Finally the minimum sump flooding in the sump for recirculation, uses the minimum water volume limit to determine a minimum available RWST volume. The upper limit on boron concentration of 2500 pam is used to determine the maximum allowable time to switc1 to hot leg recirculation following a LOCA. The purpose of switching from cold leg to hot leg injection is to avoid boron precipitation in the c, ore following the accident. l I 1 l l' l
.q U
BYRON - UNITS 1 & 2 B 3.5.4 -4 6/12/98 Revision A l
RWST B 3.5.4
' BASES APPLICABLE SAFETY ANALYSES (continued)
IntheECCSanaIysis,thecontainmentspraytemperatureis assumed to be equal to the RWST lower temperature limit of 35 F. 'If the lower temperature limit is violated. the containment spray further reduces containment pressure. The reduced containment pressure lowers the quality of steam exiting the break thus decreasing the rate which the steam is vented to the containment atmosphere. The decreased rate of steam vented to the containment atmosphere results in a corresponding decrease in the rate the Reactor Coolant System pressure drops and the rate ECCS' fluid is injected in the core thereby causing a r.ise in Jeak clad temperature. The upaer temperature limit of 100 is used in the small break _0CA analysis and containment OPERABILITY analysis. Exceeding this temperature vtill result in'a higher peak clad temperature, because there is less heat transfer from the core to the injected water for the small break LOCA and higher containment pressures due to reduced containment spray cooling capacity. For the containment response following'an MSLB. the lower limit on boron concentration and the up)er limit on RWST water temperature are used to
. . maximize t1e total energy release to containment.
The limits on RWST level and boron concentration also ensure that the post-LOCA sump pH will be between 8.0 and 11.0. The minimum and maximum pH values are verified for each fuel cycle using conservative maximum and minimum RWST volumes and the maximum and minimum allowed RWST boron concentrations. The LOCA offsite dose analysis assumes a conservatively low sump pH for the re-evolution of iodine from the sump. Ensuring that the minimum sump pH is at least 8.0 protects mechanical components and equipment l inside containment frQE the effects of chloride induced
- stress corrosion cracking. Ensuring that the maximum sump pH is no greater.than 11.0 limits the production of hydrogen due to the corrosion of aluminum and zinc inside containment. Finally, the limits on RWST boron concentration also ensure that the containment spray pH is acceptable. The~ calculation of the iodine removal effectiveness of the containment spray assumes a conservatively low containment spray pH.
The RWST satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii). n O BYRON - UNITS'1.& 2 B 3.5.4 - 5 6/12/98 Revision A 1
. RWST-B 3;5.4 L
,.. BASES LC0" The RWST ensures that an adequate su) ply.of borated water is
.available to cool and depressurize tie containment in the event of a Design Basis Accident (DBA) 'to cool and cover the core in the event of a LOCA. to maintain the-. reactor subcritical following a DBA.~ and to ensure adequate level in
-the containment sump to su) port.ECCS and Containment Spray L1, j, System pump operation in tie recirculation mode.
l To be considered OPERABLE. the RWST must meet the water u volume, boron concentration, and temperature limits (including vent path)' established in the SRs.
. APPLICABILITY .In MODES 1, 2; 3 and 4. RWST OPERABILITY requirements are dictated by ECCS and Containment Spray-System OPERABILITY.
requirements. Since both the ECCS and the Containment Spray L System must be'0PERABLE in MODES 1, 2..3.'and 4. the RWST L' must also be OPERABLE ~to support their operation. In l '. MODES 5'and.6. the ECCS and Containment Spray System are not required to be OPERABLE. Therefore, the RWST is. not
.recuired to be OPERABLE'in MODES 5 and 6 to support the ECCS P anc Containment ~ Spray System.
Jo
' ACTIONS- A_l i
]
! With RWST boron concentration or borated water temperature l not.within limits, they must be returned to within limits within 8 hours.. Under these conditions'neither the ECCS nor the Containment Spray System can perform its. design
-function.LTherefore,
.the tank to OPERABLEondition. c, promptThe action 8 hourmust be limit.to takenrestore to restore L
the RWST temperature or: boron. concentration to within limits was developed considering the time required to change either ,
-the boron concentration or, temperature and the fact that the l p
contents of the' tank are still: dvailable for injection. ji 1 1 1 l: ; I hE
$ j a L Y '
' BYRON -: UNITS 1 & 2- ~ B '3.5.4 - 6 8/3/98 Revision H l l
l u .
l. RWST-B 3.5.4-BASES-ACTIONS-(continued) L fL1 ) With the RWST inoperable for reasons other than Condition A (e.g . water volume) it must be restored to OPERABLE status
- . within 1 hour In this Condition. neither the ECCS nor the Containment Spray System can perform its design function. Therefore..
prompt action must;be taken to restore the tank to OPERABLE status or to place the unit in a MODE in which the RWST is not required. The short time limit of 1 hour to restore the RWST to OPERABLE status is based on this condition simultaneously affecting redundant trains.
' C.1 and C.2 ,
3 If the RWST cannot be returned to OPERABLE status within the associated Completion Time, the unit must be brought to a MODErin which the LC0 does not apply. To achieve this i statu . the unit must be brought to at least MODE 3 within : 6 hours and to MODE 5.within 36 hours. The allowed
- Completion Times are reasonable, based on operating
,1 D'O experience. to reach the required unit conditions from full power conditions in'an orderly ~ manner and without- l challenging unit systems. , L m SURVEILLANCE SR 3.5.4.1 REQUIREMENTS-The RWST borated water temperature should be verified every
- 24 hours to be within the limits-assumed in the accident.
.anal yses-b an d . This Fi~equency is sufficient to identify a
. temperature change that would approach either limit and has i been shown to be acceptable through operating experience.
The SR is modified by a Note that eliminates.the requirement to perform this Surveillance when ambient air tem]eratures are within the operating limits of the RWST. Witi ambient a
, air temperatures within the band, the RWST temperature
.should not exceed the li.mits.
ll O. ' B RON - UNITS 1 & 2 B 3.5.4 - 7 6/12/98 Revision A' s r L.____ _ _ _ _ _ _ _ _ _ - _ . _ . _ _ _ . _ _ _ . _ _ _ _ . _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ . . _ _ . _ . _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _
l RWST B 3.5.4 . l BAS.ES ['] SURVEILLANCE REQUIREMENTS (continued) , 1 SR 3.5.4.2 Heat traced portions of the RWST vent path should be verified every 24 hours to be within the temperature limit needed to prevent ice blockage and subsequent vacuum formation in the tank during rapid level decreases caused by q accident conditions. This Frequency is sufficient to identify a tem]erature change that would ap] roach the lower ! limit and has )een shown to be acceptable t1 rough operating experience. l The SR is modified by a Note that eliminates the requirement to perform this Surveillance when the ambient air i temperature is a 35 F. With ambient air temperature above this limit the RWST vent path will be free of ice blockage. ; SR 3.5.4.3 The RWST water volume should be verified every 7. days to be above the required minimum level of 89% (useable volume of
> 395.000 gallons) in order to ensure that a sufficient 9 initial supply is available for injection and to support (d 4 continued ECCS and Containment Spray System pump operation on recirculation. Since the RWST volume is normally stable i
I and protected by a low level alarm, a 7 day Frequency is appropriate and has been shown'to be acceptable through operating experience. SR 3.5.4.4 The boron. concentration of the RWST should be verified every 7 days to be within the required. limits. This SR ensures that the reactor will Temain subcritical following a LOCA and will limit the power level increase and subsequently returns the reactor to subcritical immediately following an MSLB. Further, it assures that the resulting sump pH will be maintained in an acceptable range so that boron-precipitation in the core will not occur, sufficient iodine will be removed to limit offsite doses, stress corrosion cracking of equipment will be minimized, and hydrogen i production will be minimized. Since the RWST volume is normally stable, a 7 day sampling Frequency to verify boron concentration is appropriate and has been shown to be acceptable through operating experience.
- Q V
l BYRON - UNITS 1 & 2 , B 3.5.4 - 8 6/12/98 Revision A 1 L
l RWST l B 3.5.4 l l
/ BASES
(-T> REFERENCES 1. WCAP-13964. Revision 2. " Commonwealth Edison Company. I Byron /Braidwood Units 1 & 2. Increased Steam Generator Tube Plugging / Reduced Thermal Design Flow / Positive Moderator Temperature Coefficient Analysis Program. ! Engineering / Licensing Report." September 1994.
- 2. UFSAR, Chapter 15.
- 3. UFSAR. Section 6.2.1. i l
l l l l I (") (__/ I
)
be l l ( l f(f%) i BYRON - UNITS 1 & 2 B 3.5.4 - 9 6/12/98Revisiond l 1
n . Seal Injection Flow
, B 3.5.5 i
(3 B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l~C)- B 3.5.5 Seal Injection Flow BASES' BACKGROUND The function of the seal injection throttle valves during an accident is similar to the function of. the ECCS throttle valves in that each restricts flow from the centrifugal charging pump header to the Reactor Coolant System (RCS). The restriction on Reactor Coolant Pump (RCP) seal injection flow limits the amount of ECCS flow that would be diverted from the injection path following an accident. This limit is based on . safety analysis assumptions that are required because RCP seal injection flow is not isolated during Safety Injection (SI). I APPLICABLE All ECCS subsystems are taken credit for in the large SAFETY ANALYSES break Loss Of Coolant Accident (LOCA) at full power (Ref. 1). The centrifugal charging pumps are also credited
,o in the small break LOCA analysis. These two LOCA analyses
, (') ' establish the minimum flow for the ECCS pumas. The steam generator tube rupture and main steam line ]reak event analyses also credit the centrifugal charging pumps, but are not limiting in their design. Reference to these analyses is made in assessing changes to the Seal Injection System for evaluation of their effects in relation to the acceptance limits in these analyses. l r\ \ U - I
\
BYRON - UNITS 1 & 2 B 3.5.5 - 1 6/12/98 Revision A
]
I 1 u --- - - - - - - - - -J
Seal Injection Flow B 3.5.5 BASES APPLICABLE SAFETY ANALYSES (continued) This LCO ensures that seal injection flow will be sufficient for RCP seal integrity but limited so that the ECCS trains will be capable of delivering sufficient water to match boiloff rates soon enough to minimize uncovering of the core following a large LOCA. It also ensures that the , centrifugal charging pumps will deliver sufficient water for a small LOCA and sufficient boron to maintain the core subcritical. For smaller LOCAs. the charging pumps alone deliver sufficient fluid to overcome the loss and maintain l RCS inventory. ITS Figure 3.5.5-1 was developed by using a conservative combination of plant data to establish a minimum flow loss coefficient for the seal injection line. Based on the conservative data. Figure 3.5.5-1 ensures adequate flow to the Reactor Coolant Pump seals while ensuring the safety analysis assumption for ECCS flow are maintained. Seal injection f. low satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii). LCO The intent of the LC0 limit on seal injection flow is to
, make sure that flow through the RCP seal water injection line is low enough to ensure that sufficient centrifugal charging pump injection flow is directed to the RCS via the injection points (Ref. 2).
The LCO is not strictly a flow limit, but rather a flow limit based on a flow line resistance. In order to establish the proper flow line resistance, a pressure and flow must be known. The flow line resistance is established by adjusting the RCP seal injection flow in the acceptable region of Figure 3.5.5-1 at a given pressure' differential between the charging Eader and the RCS. The flow limits established by Figure 3.5.b-1 ensure that the minimum ECCS flow assumed in the safety analyses is maintained. The limit on seal injection flow must be met to render the l ECCS OPERABLE. If this condition is not met. the ECCS flow will not be as assumed in the accident analyses. l
- BYRON - UNITS 1 & 2 B 3.5.5 - 2 6/12/98 Revision A
l Seal Injection Flow B 3.5.5 1 BASES l APPLICABILITY In MODES 1. 2. and 3. the seal injection flow limit is ! dictated by ECCS flow requirements, which are specified for I MODES 1. 2. 3. and 4. The seal injection flow limit is not applicable for MODE 4 and lower however, because high seal injection flow is less critical as a result of the lower initial RCS pressure and decay heat removal requirements in these MODES. Therefore. RCP seal injection flow must be limited in MODES 1. 2. and 3 to ensure adequate ECCS performance. ACTIONS A.1 l With the seal injection flow exceeding its limit, the amount of charging flow available to the RCS may be reduced. Under l this Condition, action must be taken to restore the flow to below its limit. The operator has 4 hours from the time the flow is known to be above the limit to correctly position the manual valves and thus be in compliance with the accident analysis. The Completion Time minimizes the ; potential exposure of the plant to a LOCA with insufficient i e~' injection flow and provides a reasonable time to restore i seal injection flow within limits. This time is (O' conservative with respect to the Completion Times of other j ECCS LCOs: it is based on operating experience and is ; sufficient for taking corrective actions by operations : personnel. B.1 and B.2 i
. When.the Required Actions cannot be completed within the 1 required Completion Time, a controlled shutdown must be !
initiated. The CompldG on Time of 6 hours for reaching MODE 3 from MODE 1 is a reasonable time for a controlled shutdown, based on operating experience and normal cooldown rates, and does not challenge plant safety systems or operators. Continuing the unit shutdown begun in Required Action B.1. an additional 6 hours is a reasonable time, based on operating ex)erience and normal cooldown rates. to reach MODE 4, where t1is LC0 is no longer applicable. p V BYRON - UNITS 1 & 2 B 3.5.5 - 3 6/12/98 Revision A l l
. Seal Injection Flow i B 3.5.5 A BASES V
SURVEILLANCE SR 3.5 5.1 REQUIREMENTS I Verification every 31 days that the manual seal injection throttle valves are adjusted to give a flow within the limit ensures that proper manual seal injection throttle valve - position, and hence, proper seal injection flow, is maintained. To verify acceptable seal injection flow. the , following is performed:' differential pressure between the charging header (PT-120) and the RCS is determined and the seal injection flow is verified to be within the limits of Figure 3.5.5-1. The Frequency of 31 days is based on 3 engineering judgment and is consistent with other ECCS valve ' Surveillance Frequencies. The Frequency has proven to be acceptable through operating experience.' As noted, the Surveillance is not required to be performed until 4 hours after the RCS pressure has stabilized within a 20 psig range of normal operating pressure. The RCS l i pressure requirement is specified since this configuration will produce the required pressure conditions necessary to assure that the manual "alves are set correctly. The exception is limited to 4 hours to ensure that the
- Surveillance is timely.
REFERENCES 1. UFSAR Chapter 6 and Chapter 15. l
- 2. 10 CFR 50.46. j i
l O ' BYRON - UNITS 1 & 2 B 3.5.5 - 4 6/12/98 Revision A
1
)
l Accumu'ators f .. < c 3.5.1
> s t
.- 13.5 EMERGENCYfCORE COOLING SYSTEMS (ECCS) ih; 3.5'il Accumulators' LCOJ 3.5.1L :Four ECCS accumulators shall be OPERABLE.
h - APPLICABILITY: ' MODES 1 and 2-. . wi MODE 3 with Reactor Coolant System (RCS) pressure 4
> 1000 psig.
7 LACTIONS-
- CONDITION. REQUIRED ACTION l COMPLETION TIME
~
< A.:;.One accumulator- A.1- Restore boron 72 ho'urs
* .. inoperable due to concentration.to
- boron concentration within limits.
not within limits.
~-
s H ?B. lOne ' accumulator ' B.1 Restore: accumulator 1 hour-I t iinoperable for reasons .to'0PERABLE status. LT =other:than:
' Condition A.
1. l
- C. . Required Action and C.1- Be in MODE 3; 6 hours nassoc'iated. Completions 1 Time' of Condition A: AND-Lor B not mit.
l . C.2 Reduce RCS pressure 12 hours to's 1000 psig. . .. r+ 7 0.1 Enter LCO 3.0.3. Immediately 3 '
- 10. :Two or more i .- : accumulators :
Lf Linoperable. m M Z. [ N/ri ?BRAIDWOOD: UNITS.1 &L2- 3.5:.1-1 6/22/98 Revision H Ua y h3 /
= w__=_:________-__. _ _ . _ _ _ =
Accumulators i 3.5.1 l i SURVEILLANCE REQUIREMENTS ( SURVEILLANCE FREQUENCY l SR 3.5.1.1 Verify each accumulator isolation valve is 12 hours fully open. 4 SR 3.5.1.2 Verify borated water level in each 12 hours accumulator is a 31% and s 63%. i l SR 3.5.1.3 Verify nitrogen cover pressure in each 12 hours accumulator is a 602 psig and s 647 psig. SR 3.5.1.4 Verify boron concentration in each 31 days accumulator is a 2200 ppm and s 2400 ppm. ( SR 3.5.1.5 NOTE Only required to be performed for affected accumulators after each solution volume increase of a 10% of indicated level that is not the result of addition from the refueling water storage tank containing a boron concentration a 2200 ppm and
. s 2400 ppm.
-Verify boron concentration in each Once within accumulator is a 2200 ppm and s 2400 ppm. 6 hours SR 3.5.1.6 Verify power is removed from each 31 days accumulator isolation valve operator.
l p LJ BRAIDWOOD -' UNITS 1 & 2 3.5.1-2 7/9/98 Revision A l
)
ECCS - Operating
, 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 ECCS--Operating LCO 3.5.2 Two.ECCS trains shall be OPERABLE.
NOTES
- 1. In MODE 3. .both Safety Injection (SI) pump flow paths and'a portion of both Residual Heat Removal (RHR) pump flow paths may be isolated by closing the isolation i valves for up to .2 hours to perform pressure isolation j valve testing per SR 3.4.14.1.
- 2. In M0EE 3 a aortion of both Residual Heat Removal (RHR) pump flow patas may be isolated by closing the isolation valves. for up to 2 hours to perform pressure isolation ,
valve testing per SR 3.4.14.1. provided an alternate d means of cold leg injection is available for.each ! isoleted flow path. APPLICABILITY: MODES 1 2., and 3. 'O V ACTIONS CONDITION- REQUIRED ACTION COMPLETION TIME- ; I A; .0ne train inoperable
~
A.1 ' Restore train to 7 days OPERABLE' status. B. lTwo trains inoperable.. B.1 Restore one train to 72 hours
, OPERABLE status.
- 1 L At least 100% of the >
- ECCS flow equivalent !
!L to a-single OPERABLE ECCS train available. (continued) , BRkIDWOOD-UNITS 1~&2 3.5.2-1 7/9/98 Revision A v t
l ECCS - Operating 3.5.2 , (3 ACTIONS (continued) V CONDITION REQUIRED ACTION COMPLETION TIME , C. Required Action and C.1 Be in MODE 3. 6 hours i associated Completion ! Time not met. AND l C.2 Be in MCDE 4. 12 hours . i l 1 l I s
'm BRAIDWOOD'- UNITS 1 & 2 3.5.2-2 7/9/98 Revision A i
l ECCS - Operating 3.5.2 l (~~' ' SURVEILLANCE REQUIREMENTS L SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the 12 hours listed position with power to the valve operator removed. Number Position Function MOV SI8806 Open Suction to SI Pumps MOV SI8835 Open SI Pump Discharge to Reactor Coolant System (RCS) Cold Legs MOV SI8813 Open SI Pump Recirculation to the Refueling Water Storage Tank MOV SI8809A Open RHR Pump Discharge to RCS Cold Legs n Q, MOV SI8809B Open RHR Pump Discharge to RCS Cold Legs MOV SI8840 Closed RHR Pump Discharge to RCS Hot Legs MOV SI8802A Closed SI Pump Discharge to RCS Hot Legs MOV SI8802B Closed S.L Pump Discharge to RCS Hot Legs SR 3.5.2.2 Verify each ECCS manual, power operated. 31 days and automatic valve in the flow path, that is not locked, sealed, or otherwise secured in position, is in the correct position. l SR 3.5.2.3 Verify ECCS piping is full of water. 31 days p (continued) V BRAIDWOOD - UNITS 1 & 2 3.5.2-3 -7/9/98 Revision A
ECCS - Operating 3.5.2 ('] SURVEILLANCE REQUIREMENTS (continued) SURVEILLANCE FREQUENCY SR 3.5.2.4 Verify each ECCS pump's developed head at In accordance the test flow point is greater than or with the { equal to the required developed head. Inservice Testing Program j I l SR 3.5.2.5 Verify each ECCS automatic valve in the 18 months flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal. SR 3.5.2.6 Verify each ECCS pump starts automatically 18 months on an actual or simulated actuation signal. IL 'i SPs 3.5.2.7 Verify for each ECCS throttle valve listed below, each position stop is in the correct 18 months position. Valve Number Valve Function SI8810 A.B.C.D Centrifugal Charging System SI8822 A.B.C.D SI System (Cold Leg)
'SI8816 A.B.C.D SI System (Hot Leg) l SR 3.5.2.8 Verify. by visual inspection, each ECCS 18 months train containment sump suction inlet is not restricted by debris and the suction inlet l
screens show no evidence of structural distress or abnormal corrosion. (O V BRAIDWOOD - UNITS 1 & 2 3.5.2-4 7/9/98 Revision A
t ECCS - Shutdown 3.5.3 3.5. EMERGENCY CORE COOLING SYSTEMS (ECCS)
>3.5.3 ECCS -Shutdown sLC0 3.5.3 One ECCS train shall be OPERABLE.
NOTE- - A Residual Heat Removal (RHR) train may be considered OPERABLE during. alignment and operation for decay heat removal, if capable of being manually realigned to the ECCS mode of operation. APPLICABILITY: MODE 4. - ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Required ECCS RHR A.1 Initiate action to Immediately ! ! .m- subsystem inoperable. restore required ECCS , (' - RHR subsystem to OPERABLE status. 9 I Required ECCS. B. B.1 Restore required ECCS 1 hour centrifugal charging centrifugal charging subsystem inoperable. subsystem to OPERABLE status. C,.: Required Action and C .1 - Be in MODE 5. 24 hours associated Completion Time of Condition B not met. l l: l-j kJ l h . BRAIDWOOD -' UNITS 1.& 2 3.5.3-1 7/9/98 Revision A -
- i. ,
i b
r________--- _ - - - - - _ - _ _ , - - _ - _ - - - - - - - - - - - _ - - _ - - . - - _ _ - _ . - - . - _ _ - - - - - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . . - i ECCS - Shutdown 3.5.3 (] SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.3.1 The following SRs are applicable for all In accordance equipment required to be OPERABLE: with applicable SRs SR 3.5.2.1 SR 3.5.2.7 SR 3.5.2.3 SR 3.5.2.8 l
- SR 3.5.2.4 >
l l l l l i O 1 l
.O.
L)' BRAIDWOOD -~ UNITS 1 & 2 3.5.3-2 7/9/98Revisiond' I.
l RWST 3.5.4 ' ~ 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.4 Refueling Water Storage Tank (RWST)
~
LC0 3.5.4 The RWST shall be OPERABLE. APPLICABILITY: MODES 1. 2, 3. and 4.
. . ACTIONS-CONDITION REQUIRED ACTION COMPLETION TIME A. RWST boron A.1 Restore RWST to 8 hours concentration not OPERABLE status.
within limits. OB , 1 RWST borated water l temperature not within p limits. V B. RWST inoperable for B.1 Restore RWST to 1 hour reasons other than OPERABLE status. Condition A. I C. Required Action and C.1 Be 1n MODE 3. 6 hours l associated Completion l Time not met. AND i C.2 Be'in MODE 5. 36 hours l i BRAIDWOOD - UNITS 1 & 2 3.5.4-1 7/9/98 Revision A
RWST 3.5.4 l .
/ SURVEILLANCE REQUIREMENTS l
l V] SURVEILLANCE FREQUENCY l i SR 3.5.4.1 NOTE Only required to be performed when ambient < air temperature is < 35 F or > 100 F. l l l Verify RWST borated water temperature is 24 hours 1 2 35 F and s 100 F. 1 SR 3.5.4.2 NOTE Only required to be performed when ambient air temperature is < 35 F. Verify RWST vent path temperature is 24 hours a 35 F. [ SR 3.5.4.3 Verify RWST borated water level is a 89%. 7 days O) w SR 3.5.4.4 Verify RWST boron concentration is 7 days a 2300 ppm and s 2500 ppm. l (' V f ) BRAIDWOOD - UNITS 1 & 2 3.5.4-2 7/9/98 Revision A l i
Seal Injection Flow . 3.5.5 - 3.5- EMERGENCY CORE. COOLING SYSTEMS (ECCS) 3;5.5 Seal: Injection Flow' - LC0 3.5.5 Reactor coolant pump seal injection flow shall be within the i limits of Figure 3.5.5-1 . l APPLICABILITY: MODES 1, 2, and 3. ' 1
.ACTI0NS CONDITION REQUIRED ACTION COMPLETION TIME A. Seal injection flow. A.1 Adjust manual seal 4 hours not within limit injection throttle valves-to give a flow within the limits of Figure 3.5'.5-1.
' B. Required Action and B.1 Be in MODE 3. 6 hours associated Completion Time not met. AND B.2 Be in MODE 4. 12 hours i
l l I .. l .: n U . . BRAIDWOOD.- UNITS 1-&'2. 3.5.5-1 7/9/98 Revision A L _ . . . _ , . . _ _ _ _ _ _ _ . _ . _ _ _ _ _ . . _ _ . - _ _ _ - _ _ _ _ . _ _ _ . _ _ _ _ _ _ - _ _ _ . _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ - _ . _ . _ _ . _ _ _ . _ . . _ _ _ _ . .m._ ___
Seal Injection Flow 3.5.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.5.1 = NOTE Not required to be performed until 4 hours after the Reactor Coolant System pressure stabilizes at = 2215 psig and 5 2255 psig. Verify manual seal injection throttle 31 days valves are adjusted to give a flow within the limits of Figure 3.5.5-1. 1 0 O BRAIDWOOD - UNITS 1 & 2 3.5.5-2 7/9/98ReUisionA i
Seal Injection Flow , 3.5.5 '
, ~j
= 3 3 0 ._ . _ . __ .
V E [+ ,, .,, a. - - (60.36, 225)
% /d rerr7v rrivv vre YAW Wg er ;/MxNp;f ,v e m , i s y;e r ce r ,. , v v v* c y-a%v (xs;Q 57 v&4V*
"- l
?45 N x x e j
'r 2,,
t y,
- , Zg%
X , evya,qN
> Asahs%g'Nay g;Av u.y,yN,% yt;$,? y4g,'
wW %<DI,W q
~ 0 0
' W '
~
vf4^ X *
.. Y %%
/y /
se34WlAXyjg, r : tgX x s- (56.9i, ~200)
- 4 y , A M,, ,y % 5 As d Sw$s '
~
1.,<a: -
*ff,v w,$<_$, . , *4"/
, , .x ,
s ,W y vf- D2x Z/k f;-
# N N&IY W2$ m y n y W/fy%q#u a* $ ,
f ACCEPTABLE REGION gv54>^Q f, ~ ~ ~ .3<Wa$$.$W,F ki -- 19oi . A.MaN%%%% a . n j 5' ^ M, n a A X ,ms yu; @ X Q X s,y: $Q (49.28,150) j - f 'st?n$e d ? &Y g%% %
?z'$Q:
E 125E [ , , }( ., /* e App' z py p ,/ ,' t u.: W Av , qs ~ ~ / 3 '^ R I ' s '~ ! .!
.;i.
~~
100:- 1 4xJ~/^h;$$$dX sf ?r:;?,gn x j , /,,y? (10.,I,100J
'; x$$$ %y y g k e *gx x ,
Av/va;>Hn As 6v , e _, 4 ,: XA ' I D ' ~ -~ Q'iM>.'tQ^&
.% .x . ... . ,
s O. f , Q,1, 63.43) (3,.,, 63, .43) UNACCEPTABLE REGION ; i [j .,_ 9 9 2- _ - _ .-._ . .._ -. . - - . . - - _ 1
=
C: E 25- - - - - - - - - - - - " - - -
-------F---------r,---- ,
l
' h l
/.
~ '
E
' ~
O
$ 20 30 <10 50 60 70 SEAL INJECTION FLOW (GPM)
Figure 3.5.5-1 (page 1 of 1) Seal Injection Flow Limits l
/
O BRAIDWOOD - UNITS 1 & 2 , 3.5.5-3 7/9/98 Revisiori A i l' L___-_-_-_--.._.-_.-. -- - - - - . _ - - _ - - -_.
Accumulators B 3.5.1 (') v B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.1 Accumulators BASES BACKGROUND The functions of the ECCS accumulators are to supply water to the reactor vessel during the blowdown phase of a Loss Of Coolant Accident (LOCA), to provide inventory to help accomplish the refill phase that follows thereafter, and to 3rovide Reactor Coolant System (RCS) makeup for a small areak LOCA. The blowdown phase of a large break LOCA is the initial , period of the transient during which the RCS departs from ' equilibrium conditions, and heat from fission product decay. hot internals, and the vessel continues to be transferred to > the reactor coolant. The blowdown phase of the transient ends when the RCS pressure falls to a value approaching that ' of the containment atmosphere. In the refill phase of a LOCA which immediately follows the blowdown phase, reactor coolant inventory has vacated the gmI~ core through steam flashing and ejection out through the 4 break. The core is essentially in adiabatic heatup. The i balance of accumulator inventory is then available to help j fill voids in the lower plenum and reactor vessel downcomer so as to establish a recovery level at the bottom of the core and ongoing reflood of the core with the addition of Safety Injection'(SI) water.
. The accumulators are pressure vessels partially filled with
. borated water and pressurized with nitrogen gas. The accumulators are passive components. since no operator or
- control actions are required in order for them to perform their function. Internal accumulator tank pressure is sufficient to discharge the accumulator contents to the RCS.
if RCS pressure decreases below the accumulator pressure. ( ' BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 1 6/12/98 Revision
Accumulators
, B 3.5.1
() LJ BASES BACKGROUND (continued) Each accumulator is piped into an RCS cold leg via an accumulator line and is isolated from the RCS by a motor oaerated isolation valve and two check valves in series. T1e motor operated isolation valves are interlocked by P-11 with the pressurizer pressure measurement channels to ensure that the valves will automatically open as RCS pressure increases to above the permissive' circuit P-11 setpoint. This interlock also prevents inadvertent closure of the valves during normal operation The j valves will automatically open, however, prior to an asaccident. a result of an SI signal. These features ensure that the valves meet the requirements of the Institute of Electrical and Electronic Engineers (IEEE) Standard 279-1971 (Ref. 1) for "o]erating bypasses" and that the accumulators will be availa)le for injection without reliance on operator action. The accumulator size, water volume, and nitrogen cover pressure are selected so that three of the four accumulators are sufficient to partially cover the core before significant clad melting or zirconium water reaction can p occur following a LOCA. The need to ensure that three Q' accumulators are adequate for this function is consistent with the LOCA assumption that the entire contents of one accumulator will be lost via the RCS pipe break during the blowdown phase of the LOCA. APPLICABLE The accumulators are assumed OPERABLE in both the large and SAFETY ANALYSES small break LOCA analyses at full power (Refs. 2 and 3) .
.These are the Design Basis Accidents (DBAs) that establish the acceptance limits Tor the accumulators. Reference to the analyses for these DBAs is used to assess changes in the accumulators as they relate to the acceptance limits.
l
/~%
U I BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 2 6/12/98 Revision A 1 l u
Accumulators B 3.5.1 O BASES V APPLICABLE SAFETY ANALYSES (continued) In performing the LOCA calculations. conservative assumptions are made concerning the availability of ECCS flow. In the early stages of a LOCA. with or without a loss of offsite power. the accumulators provide the sole source of makeup water to the RCS. The assumption of loss of offsite power is required by regulations and conservatively . imposes a delay wherein the ECCS pumps cannot deliver flow until the emergency diesel generators start. come to rated speed, and go through their timed loading sequence. In cold leg break scenarios, the entire contents of one accumulator are assumed to be lost through the break. The limiting large break LOCA is a double ended guillotine break at the discharge of the reactor coolant pump. During this event, the accumulators discharge to the RCS as soon as RCS pressure decreases to below accumulator pressure. As a conservative estimate, no credit is taken for-ECCS pump flow until an effective delay has elapsed. This delay accounts for the diesels starting and the pumps being loaded and delivering full flow. The delay time is conservatively t em set with an additional 2 seconds to account for SI signal generation. During this time. the accumulators are analyzed V' as providing the sole source of emergency core cooling. No operator action is assumed during the blondown stage of a large break LOCA. The worst case small break LOCA analyses also assume a time i delay before pumped flow reaches the core. For the larger i range of small breaks. the rate of blowdown is such that the increase in fuel clad temperature is terminated solely by the accumulators. withJumped flow then providing continued
- cooling. As break size decreases, the accumulators and centrifugal charging pumps both play a part in terminating the rise in clad temperature. As break size continues to decrease, the role'of the accumulators continues to decrease until they are not required and the centrifugal charging pumps become solely responsible for terminating .the temperature increase.
l l
- BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 3 6/12/98 Revision A
l Accumulators B 3.5.1 , I O BASES l C/ APPLICABLE SAFETY ANALYSES (continued) This LCO helps to ensure that the following acceptance criteria established for the ECCS by 10 CFR 50.46 (Ref. 4) , will be met following a LOCA:
- a. Maximum fuel element cladding temperature is s 2200 F:
b Maximum cladding oxidation is 5 0.17 times the total i cladding thickness before oxidation:
- c. Maximum hydrogen generation.from a zirconium water reaction is s 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding ;
cylinders surrounding the fuel. excluding the cladding l surrounding the plenum volume, were to react: and ;
- d. Core is maintained in a coolable geometry.
Since the accumulators discharge during the blowdown phase of a LOCA, they do not contribute to the long term cooling requirements of 10 CFR 50.46. 4 1 For both the large and small break LOCA analyses, a nominal I contained accumulator water volume is used. The contained water volume is the same as the deliverable volume for the accumulators, since the accumulators are emptied, once f discharged. For small breaks, the peak clad temperature is not sensitive to the accumulator water volume. For large breaks, there are two competing effects regarding accumulator water volume: the amount of water available for injection versus the injection rate. While a larger water volume is a benefit, it leaves a smaller volume of nitrogen. gas in the accumulator _which results in a slower injection
- rate as the accumulator discharges. resulting in a penalty.
Conversely, while less water volume is a penalty, it will be injected at a higher rate due to the larger nitrogen gas volume. Since the range of accumulator volumes is relatively small along with the resulting effect on peak cladding temperature, a nominal water volume is used. The analysis conservatively ignores the line water volume f, rom the accumulator to the check valve. The safety analysis assumes a nominal water volume of 7106 gallons based on minimum and maximum volumes of 6995 gallons (~31% of indicated level) and 7217 gallons (63% of indicated level). j respectively. L O BRAIDWOOD - UNITS 1.& 2 B 3.5.1 - 4 6/12/98 Revision A u:----_--------_-- _ - - - - - - _ - . - - - - - - - - - - - - - - - - - -
I J Accumulators B 3.5.1
.O BASES V
APPLICABLE SAFETY ANALYSES (continued) The minimum boron concentration setpoint is used in the post LOCA boron concentration calculation. The calculation is performed to assure reactor subcriticality in a post LOCA environment. Of particular interest is the large break LOCA. since no credit is taken for control rod assembly insertion. A reduction in the accumulator minimum boron concentration would produce a subsequent reduction in the I available containment sump concentration for post LOCA ! shutdown and an increase in the maximum sump pH. The maximum boron concentration is used in determining the cold leg to hot leg recirculation injection switchover time and minimum sump pH. I The large and small break LOCA analyses are performed at the minimum nitrogen cover 3ressure, since sensitivity analyses have demonstrated that ligher nitrogen cover pressure ; results in a computed peak clad temperature benefit. The ' maximum nitrogen cover pressure limit prevents accumulator relief valve actuation. and ultimately preserves accumulator integrity. The effects on containment mass and energy releases from the {qj accumulators are accounted for in the appropriate analyses (Refs. 2 and 3). The accumulators satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii). l LCO The LCO establishes the minimum conditions required to ensure that the accumulators are available to accomplish
- their core cooling saf~ety function following a LOCA. Four accumulators are required to ensure that 100% of the contents of three of the accumulators will reach the core during a LOCA. This is consistent with the assumption that the contents of one accumulator spill through the break. If less than three accumulators are injected during the blowdown phase of a LOCA. the ECCS acceptance criteria of 10 CFR 50.46 (Ref. 4) could be violated.
fy d BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 5 6/12/98 Revision A l L
Accumulators B 3.5.1 ; I BASES LCO (continued) I l For an accumulator to be considered OPERABLE. the isolation valve must be fully open with power removed, a contained volume a 31% and s 63% (6995 gallons to 7217 gallons) with a boron concentration a 2200 ppm and s 2400 ppm. and a nitrogen cover pressure a 602 and s 647 psig, must be met. ) , APPLICABILITY In MODES 1 and 2. and in MODE 3 with RCS pressure ! > 1000 psig. the accumulator OPERABILITY requirements are based on full power operation. Although cooling requirements decrease as power decreases, the accumulators are still required to provide core cooling as 16ng as l elevated RCS pressures and temperatures exist. ; This LCO is only applicable at pressures > 1000 psig. At pressures 5 1000 psig, the rate of RCS blowdown is such that l the ECCS pumps can provide adequate injection to ensure that peak clad temperature remains below the 10 CFR 50.46 (Ref. 4) limit of 2200 F. In MODE 3, with RCS pressure s 1000 psig, and in MODES 4. 5. l Q, n . and 6. the accumulator motor op'erated isolation valves are closed to isolate the accumulators from the RCS. This allows RCS cooldown and depressurization without discharging the accumulators into the RCS or requiring depressurization of the accumulators. BRAIDWOOD - UNITS 1 & 2 , B 3.5.1 - 6 6/12/98 Revision A
Accumulators B 3.5.1 iO g BASES ACTIONS A.1 l If the boron concentration of one accumulator is not within ' limits, it must be returned to within the. limits within 72 hours. In this Condition, ability to maintain l subcriticality or minimum boron precipitation time may. be reduced. The boron in the accumulators contributes to the l assumption that the combined ECCS water in the partially ; recovered core during the early reflooding phase of a large l break LOCA is sufficient to keep that portion of the core subcritical. One accumulator below the minimum boron concentration limit, however, will have no effect on < available ECCS water and an insignificant effect on core 1 subcriticality during reflood. Boiling of ECCS water in the core during reflood concentrates boron in the saturated liquid that remains in the core. In addition. current l analysis demonstrates that the accumulators do not discharge - following a large main steam line break. Thus. 72 hours is allowed to return the boron concentration to withi.n limits. l. B.1 q If one accumulator is inoperable for a reason other than Q boron concentration, the accumulator must be returned to OPERABLE status within 1 hour. In this Condition, the ! required contents of three accumulators cannot be assumed to reach the core during a LOCA. Due to the severity of the consequences should a LOCA occur in these conditions. the 1 hour Completion Time to open the valve, remove power to ! the valve, or restore the proper water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable accumulator to OPERABLE status. The Completion Time minimizes the potential for exposure of the
- unit to a LOCA under these conditions.
i l l i (~h () BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 7 6/12/98 Revision A i
Accumulators B 3.5.-1 D . BASES U ACTIONS (continued) C.1 and C.2 If the accumulator cannot be returned to OPERABLE status within the associated Comaletion Time, the unit must be brought to a MODE in whic1 the LCO does not' apply. To
-achieve this status, the unit must be brought to MODE-3 within 6 hours and RCS pressure reduced to 5 1000.psig within 12 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 plant systems.
D.J. If more than'one accumulator is inoperable, the unit is in a condition outside the accident analyses: therefore, LCO 3.0.3 must be entered immediately. SURVEILLANCE SR 3.5.1.1 f- REQUIREMENTS ( Each accumulator valve should be verified to be fully open every 12 hours. This verification ensures that'the - accumulators are available for injection and ensures timely discovery if a valve should be less than fully open. If an isolation valve is. not fully o)en, the rate of- injection to the RCS would be reduced. Altlough a motor operated valve position should not change with power removed, a closed i valve could result in not meeting accident analyses assumptions. This Frequency is considered reasonable in view of other administrative; controls that ensure a
- mispositioned isolation. valve is unlikely.
SR ~3.5.1.2 and SR 3.5.1.3 Every 12 hours, borated' water level and nitrogen cover 1 pressure are verified for each accumulator. This Frequency i is sufficient to ensure adequate injection during a LOCA. .! Because of the static-design of the accumulator, a 12 hour l Frequency usually allows the operator to identify changes i before limits are reached. Operating experience has shown i !~ this' Frequency to be appropriate for early detection ard l- correction of off normal trends. l
,LL BRAIDWOOD"- UNITS 1 & 2 B 3. 5.1 - 8 6/12/98 Revision A
.. i b'
Accumulators B 3.5.1 l O v BASES 1 i SURVEILLANCE REQUIREMENTS (continued) SR 3.5.1.4 The boron concentration should be verified to be within required limits for each accumulator every 31 days since the static design of the accumulators limits the ways in which the concentration can.be changed. The 31 day Frequency is . adequate to identify changes that could occur from mechanisms such as stratification or inleakage. SR 3.5.1.5 Sampling the affected accumulator within 6 hours after a 1% volume increase (nominally 70 gallons or 10% of indicated level) will identify whether inleakage has caused a reduction in boron concentration to below the required limit. It is not necessary to verify boron concentration of the accumulator after a 1% volume increase (10% indicated level increase) if the added water inventory is from the Refueling Water Storage Tank (RWST) and the boron concentration of the RWST is 2 2200 ppm and 5 2400 ppm. With the water contained in the RWST within the boron p concentration requirements of the accumulators, any added L]
\ inventory would not cause the accumulator's boron concentration to exceed the limits of this LCO.
With the only indication available to the operators in the control room being level indication in percent, a required accumulator volume . increase of 1% or an increase of 10% of indicated level woulo require the accumulator to be sarpled to verify the accumulator boron concentration is within the limits. The safety analysis assumes a nominal water volume of 7106 gallons based .QD minimum and maximum volumes of
- 6995 gallons-(31%) and 7217 gallons (63%). respectively.
These volumes are also indicated in the specific tank curves-for the SI accumulators. The 10% indicated level increase is' considered a conservative indication for a 70 gallon increase in the accumulator volume requiring an increase in the sampling requirement to verify accumulator boron concentration remains within the specified limits. O
'V BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 9 6/12/98 Revision A I
Accumulators B 3.5.1
. (~') BASES
\- /
SURVEILLANCE REQUIREMENTS (continued) SR 3.5.1.6 Verification every 31 days that power is removed from each accumulator isolation valve oaerator ensures that an active failure could not result in t1e undetected closure of an accumulator motor operated isolation valve. If this were to occur, only two accumulators would be available for injection given a single failure coincident with a LOCA. The power to the accumulator motor operated isolation va.lves is removed by opening the motor control center breaker and - tagging it out administratively. Since power is removed under-administrative control, the 31 day Frequency will provide adequate assurance that power is removed. REFERENCES 1. IEEE Standard 279-1971.
- 2. UFSAR, Chapter 15.
-- 3. UFSAR, Chapter 6.
\"' 4 10 CFR 50.46.
1-G BRAIDWOOD - UNITS 1 & 2 B 3.5.1 - 10 6/12/98 Revision A
)
ECCS - Operating B 3.5.2 ('~^. B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) q) B 3.5.2 ECCS - Operating I BASES l l BACKGROUND The function of the ECCS is to 3rovide core cooling and I negative reactivity to ensure tlat the reactor core is ! protected after any of the following accidents:
- a. Loss Of Coolant Accident (LOCA), coolant leakage greater than the capability of the normal charging l system; '
- b. Rod ejection accident: I
- c. Loss of secondary coolant accident, including I uncontrolled steam release or loss of feedwater; and i
- d. Steam Generator Tube Rupture (SGTR).
The addition of negative reactivity is designed primarily for the loss of secondary coolant accident where primary ; m cooldown could add enough positive reactivity to achieve Q criticality and return to significant power. j i There are three phases of ECCS operation: injection, cold 4 leg recirculation, and hot leg recirculation. In the ; injection phase, water is taken from the Refueling Water Storage Tank (RWST) and injected into the Reactor Coolant System (RCS) through the cold legs. When sufficient water is removed from the RWST to ensure that enough boron has been added to maintain the reactor subcritical and the containment sumps have gnough water to supply the required net positive suction head to the ECCS pumps, suction is switched to the containment sump for cold leg recirculation. After approximately 8.5 hours, the ECCS flow is shifted to the hot leg recirculation phase to 3rovide a backflush,
- . which would reduce the boiling in t1e top of the core and any resulting boron precipitation. Every 24 hours after initiation of hot leg recirculation, the flow path is i alternated between hot and cold leg recirculation.
l-f%. L) BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 1 6/12/98 Revision A I
ECCS -Operating B 3.5.2 BASES BACKGROUND (continued) The ECCS consists of three separate subsystems: centrifugal charging (high head). Safety Injection (SI) (intermediate head), and Residual Heat Removal (RHR) (low head). Each subsystem consists of two redundant. 100% capacity trains. The ECCS accumulators and the RWST are also part of the ECCS. but are not considered part of an ECCS flow path as described by this LCO. The ECCS flow paths consist of piping, valves, heat exchangers, and pumps such that water from the RWST can be injected into the RCS following the accidents described in this LCO. The major components of each subsystem are the centrifugal charging pumps < the RHR pumas, heat exchangers, and the SI pumps. Each of the three su) systems consists of two 100% capacity trains that are interconnected and redundant such that either train is capable of supplying 100% of the flow required to mitigate the accident consequences. This interconnecting and redundant subsystem design provides the operators with the ability to utilize components from opposite trains to achieve the required 100% flow to the core. I During the injection phase of LOCA recovery a single k suction header supplies water from the RWST to the ECCS pumps. Separate piaing supplies each subsystem and each train within the suasystem. The discharge from the centrifugal ' charging pumps combines prior to dividing into four supply lines, each of which feeds the injection line to one RCS cold leg. The discharge from the SI and RHR pumps divides and feeds an injection line to each of the RCS cold legs. Control valves are set to balance the flow to the RCS. This balance ensures sufficient flow to the core to meet the analysis assuinptions following a LOCA in one of the RCS cold legs. For LOCAs that are too small to depressurize the RCS below the shutoff head of the SI pumps, the centrifugal charging pumps supply water until the RCS pressure decreases below the SI pump shutoff head. During this period, the steam generators are used to provide part of the core cooling function. (J~T \ BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 2 6/12/98 Revision A U - _ ____ _ ________ _____ __ _______ __. .
--- - - _ _ - _ - a
ECCS -Operating B 3.5.2 O O BASES BACKGROUND (continued) During the recirculation phase of LOCA recovery. RHR pump suction is transferred to the containment sump. The RHR pumps then supply the other ECCS pumps. Initially, recirculation is through the same paths as the injection 3hase. Subsequently, recirculation alternates injection 3etween the hot and cold legs. The centrifugal charging subsystem of the ECCS also functions to supply borated water to the reactor core j fol'using increased heat removal evcnts. such as a Main l Steam Line Break (MSLB). The limiting design conditions ' occur when the negative moderator temperature coefficient is highly negative, such as at the end of each cycle. During low temperature conditions in the RCS. limitations i are placed on-the maximum number of ECCS pumps that may be 1 OPERABLE. Refer to the Bases for LCO 3.4.12. " Low Temperature Overpressure Protection (LTOP) System.." for the basis of these requirements. The ECCS subsystems are actuatea upon receipt of an SI p signal. The actuation of safeguard loads is accomplished in Q a programmed time seq"ence. the safeguard loads start immediately in the programmed If offsite power is available, sequence. If offsite power is not available. the Engineered Safety Feature (ESF) buses shed normal operating loads and are connected to the emergency Diesel Generators (DGs). Safeguard loads are then actuated in the programmed time sequence. The time delay associated with diesel starting.
. sequenced loading, and pump starting determines the time
. required before pumped flow is available to the core following a LOCA. __
The active ECCS components along with the passive accumulators and the RWST covered in LCO 3.5.1..
" Accumulators." and LCO 3.5.4. " Refueling Water Storage Tank (RWST)." provide the cooling water necessary to meet GDC 35 (Ref. 1).
l l LO ~ BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 3 6/12/98 Revision A
ECCS - Operating
, B 3.5.2 lp BASES
- v ,
APPLICABLE The LCO helps to ensure that the following acceptance l SAFETY ANALYSES criteria for the ECCS. established by 10 CFR 50.46 (Ref. 2). will be met following a LOCA:
- a. Maximum fuel element cladding temperature is s 2200 F:
- b. Maximum cladding oxidation is s 0.17 times the total cladding thickness before oxidation;
- c. Maximum hydrogen generation from a zirconium water I reaction is s 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel excluding the cladding surrounding the plenum volume, were to react:
- d. Core is maintained in a coolable geometry; and
- e. Adequate long term core cooling capability is maintained.
The LCO also limits the potential for a post trip return to power following an MSLB event and ensures that containment g temperature limits are met. Each ECCS subsystem is taken credit for in a large break LOCA event at full power (Ref. 3). This event establishes the requirement for runout flow for the ECCS pumps, as well as the maximum response time for their actuation. The centrifugal charging pumps and SI pumps are credited in a small break LOCA event. This event establishes the flow and discharge head at the design point for the centrifugal charging pumps. The SGTR and MSLB events also credit the centrifugal charging pgDps. The OPERABILITY requirements
- for the ECCS are based on the following LOCA analysis assumptions:
- a. A large break LOCA event, with loss of offsite power and a single failure disabling one RHR pump (both emergency DG trains are assumed to operate due to '
requirements for modeling full active containment heat removal system operation); and
- b. A small break LOCA event, with a loss of offsite power and a single failure disabling one ECCS train.
l(O l V
- BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 4 6/12/98 Revision A
ECCS - Operating B 3.5.2 ; BASES APPLICABLE SAFETY ANALYSES (continued) l i During the blowdown stage of a LOCA, the RCS depressurizes as primary coolant is ejected through the break into the containment. The nuclear reaction is terminated either by , moderator voiding during large breaks or control rod l insertion for small breaks. Following depressurization. emergency cooling water is injected into the cold legs, flows into the downcomer, fills the lower plenum and refloods the core. The effects on containment mass and energy releases are I accounted for in appropriate analyses (Refs. 3 and 4). The LCO ensures that an ECCS train will deliver sufficient water to match boiloff rates soon enough to minimize the consequences of the core being uncovered following a large LOCA. It also ensures that the centrifugal charging and SI aumps will deliver sufficient. water and boron during a small 0CA to maintain core subcriticality. For smaller LOCAs. the centrifugal charging pump delivers sufficient fluid to i maintain RCS inventory. For a small break LOCA, the steam generators continue to serve as the heat sink, providing part of the required core cooling. . O The eccs tre4"e eet4ers cr4ter4o" a of 10 CFR 50.36(c)(2)(ii). LC0 In MODES 1, 2 and 3. two independent (and redundant) ECCS trains are required to ensure that sufficient ECCS flow is available assuming a single failure affecting either train. Additionally, individual components within the ECCS trains may be called upon to mitigate the consequenc'es of other transients and accidents. In MODES 1. 2. and 3. an ECCS train consists of a centrifugal charging subsystem, an SI subsystem and an RHR subsystem. Each train includes the piping instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an SI signal and automatically transferring suction to the containment sump. l (3 V BRhlDWOOD'-UNITS 1&2 B 3.5.2 - 5 6/12/98 Revision A
ECCS -Operating B 3.5.2 BASES h LC0 (continued) During an event requiring ECCS actuation. a flow path is required to 3rovide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term this flow path may be switched to take its supply from the containment sump and to supply . its flow to the RCS hot and cold legs. The flow path for each train must maintain its designed independence to ensure that no single failure can disable both ECCS trains. l The LCO is modified by two Notes that allow isolation of both SI pump flow paths and a portion of both RHR flow paths for up to 2 hours to perform pressure isolation valve testing per SR 3.4.14.1 during MODE 3. Isolation of the discharge flow paths of both SI pumps may be accom)lished by closing valve SI8835. Isolation of a portion of tie discharge flow paths of both RHR pumps may be accomplished by closing either valve SI8809A or SI8809B. With a portion of both RHR flow paths isolated. an alternate means of cold
; leg injection must be available for each isolated flow path.
s An alternate means may include: 1) OPERABLE accumulators 1 with their isolation valves either closed, but energized, or {] j
. m., open: 2) cold leg injection via the Safety Injection pumps, and the SI8821A/B and the SI8835 valves; or 3) cold leg W injection via the Centrifugal Charging pumps and the Q SI8801A/B valves.
APPLICABILITY In MODES 1. 2 and 3. the ECCS OPERABILITY requirements for
- the limiting Design B5's'is Accident, a large break LOCA. are based on full power operation. Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. The centrifugal charging pump performance is based on a small break.LOCA, which establishes the pump performance curve and has less dependence on power. The SI pump 3erformance requirements are based on a small break LOCA. 10DE 2 and MODE 3 l requirements are bounded by the MODE-1 analysis.
l f Ol BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 6 6/22/98 Revision H L__-_ _ _
i ECCS - Operating I 3 3.5.2 l BASES l APPLICABILITY (continued) l This LCO is only applicable in MODE 3 and above. Below ( MODE 3. the.51 signal setpoint is manually bypassed by operator control, and system functional requirements are i relaxed as described in LCO 3.5.3 "ECCS-Shutdown." l In MODES 5 and 6. unit conditions are such that the , probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are ! addressed by LC0 3.4.7. "RCS Loops-MODE 5. Loops Filled." : and LCO 3.4.8. "RCS Loops-MODE 5. Loops Not Filled." l MODE 6 core cooling requirements are addressed by LCO 3.9.5.
" Residual Heat Removal (RHR) and Coolant Circulation-High Water Level." and LCO 3.9.6. " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level .
ACTIONS A.1 and B.1 With one ECCS train inoperable.100% of the ECCS flow is
. provided by the remaining OPERABLE ECCS train. Required
' g Action A.1 requires that the inoperable train be restored to J OPERABLE status within 7 days. The 7 day Completion Time is
- b. based on a 3robabilistic risk assessment evaluation (Refs. 6 and 7) whic1 concludes that the Completion Time does not significantly affect the overall probability of core damage.
With two ECCS trains inoperable and at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available. Required Action B.1 requires that one train be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is based on an NRC reliability evaluation
. (Ref. 5) and-is a reasonable time for repair of many ECCS !
components. An ECCS train is inoperable if it is not capable of delivering design flow to the RCS. Individual components are inoperable if they are not capable of performing their design function or their required supporting systems are not available. , BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 7 6/12/9B Revision A l
ECCS -Operating B 3.5.2 BASES ACTIONS (continued) The LCO requires the OPERABILITY of a number of independent subsystems. Due to the redundancy of trains and the diversity of subsystems, the inoperability of one component in a train does not render the ECCS incapable of performing. its function. Neither does the inoperability of two different components, each in a different train, necessarily result in a loss of function for the ECCS. The intent of these Conditions is to maintain a combination of equipment such that 100% of the ECCS flow equivalent to a single OPERABLE ECCS train remains available. Thus. for 100% of the ECCS flow equivalent to a single .0PERABLE ECCS train to remain available, at least one train of each centrifugal charging subsystem. SI subsystem, and RHR subsystem. including an RHR heat exchanger, must be OPERABLE. This allows increased flexibility in unit operations under circumstances when components in opposite trains are inoperable. Reference 8 describes situations in which one component, such as an RHR crossover valve, can disable both ECCS trains. With one or more component (s) inoperable such that n 100% of the flow equivalent to a single OPERABLE ECCS train (' is not available. the facility is in a condition outside the accident analysis. Therefore, LCO 3.0.3 must be immediately entered. C.1 and C.2 If the ino]erable trains cannot be returned to OPERABLE status wit 1in the associated Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to MODE 3
- within 6 hours and MODE 4 within 12 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 plant systems.
l l r O BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 8 6/12/98 Revision A
ECCS - Operating B 3.5.2 (O L) BASES SURVEILLANCE SR 3 5.2.1 l REQUIREMENTS l Verification of proper motor operated valve position ensures j that the injection flow path from the ECCS pumps to the RCS is maintained. Misalignment of these valves could render both ECCS trains inoperable. Securing these valves in position by removal of power ensures that they cannot change i position as a result of an active failure or be inadvertently misaligned. These valves are of the type. described in Reference 8. that can disable the function of both ECCS trains and invalidate the accident analyses. A 12 hour Frequency is considered reasonable in view of other administrative controls that will ensure a misp'ositioned j valve is unlikely. SR 3.5.2.2 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 (e.g. , the n valves listed in SR 3.5.2.1 and SR 3.5.2.7), since these Q- were verified to be in the correct position prior to locking, sealin , or securing. A valve that receives an actuation signa is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation. Rather, it involves verification that those valves capable of being mispositioned are in the correct position. The 31 day Frequency is appropriate because the valves are operated under administrative cpatrol, and an improper valve position
- would only affect a single train. This Frequency has been shown to be acceptable through operating experience, a
l l l
\
l BRAIDWOOD - UNITS 1 & 2 , B 3.5.2 - 9 6/12/98 Revision A
( . , 1+- ECCS -Operating -
, B 3.5.2 -
. BASES,
; SURVEILLANCE REQUIREMENTS (continued) 1SR -3.5.2.3-LWith the. exception of the' operating centrifugal charging *
-pump, the ECCS pumps are normally:in:a standby, nonoperatingL mode. . As such flow 3ath piping has the potential to -
develop voids and poccets of entrained gases. The. system. will perform properly, injecting its full capacity 'into the - RCS upon. demand. by maintaining the' piping from the ECCS pumps to the RCS full of water. This will also prevent water hammer. pump cavitation, and pumping of noncondensible gas (e.g. , air. ' nitrogen, or hydrogen) into the reactor _ vessel .following an SI signal or during shutdown cooling.
.This is accomplished by venting the non-operating ECCS pump-cas.ings and.the discharge piping high points'(appl.icable to idle-RH and SI systems only) outside containment to maintain the.ECCS-piping full of water.
- In' the event that gas. is present at.eithe'r RH cold. leg -
isolation valve'(SI8809A/B) vent valve (SIO58A/B), the three y gas traps associated with the ECCS crossover piping will be
. UT inspected to confirm the pi 3ing-is'-full of water.
- SR 3.5.2.3 . requires .that the- Ri and SI~ pump. casings and
' discharge piping high point vent valves be vented. This r/ T venting surveillance does not apply to subsystems in V communication with operating systems because the flows'in these systems are ' sufficient to provide confidence that
. water. hammer which could occur from voiding would not result in unacceptable dynamic loads; During shutdown cooling operation, the exclusion would apply to the operating RH pump, in addition to the.ECCS: piping. in communication with -
. the operating pump.
- Foris'lected e portions IIf piping (i.e..-' portions involving
- the idle CV pump discharge piping up'to the first check valve on the pump discharge and miniflow lines. the stagnant
, . portion of the piping upstream of the SI8801A/B' adjacent.to the vent valve SIO45, and the piping at the 1CV207 or 2CV206
, valve if the B' CV pump is idle) the verification that the-1 piping is filled with water will be performed by ultrasonic examination. sThis examination 'will provide added assurance that the-piping is waterLsolid.- These methods are consistent'with Reference 9.
[ < b p < A-[ 1BRAIDWOOD. UNITS.1 af2 B 3.5.2 - 10 6/22/98 Revision H L :
ECCS - Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued) The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation. SR 3.5.2.4 Peri' odic surveillance testing of ECCS pumps to detect gross degradation caused by impeller structural damage or other hydraulic component problems is required by SECTION XI of the ASME Code. This type of testing may be accomplished by measuring the pump developed head at only one pbint of the pump characteristic curve. This verifies both that the measured performance is within an acceptable tolerance of the original pum) baseline performance and that the performance at tie test flow is greater than or equal to the performance assumed in the plant safety ~ analysis. SRs are specified in the Inservice Testing Program, which encompasses SECTION XI of the ASME Code. SECTION XI of the ASME Code provides the activities and Frequencies necessary to satisfy the requirements. SR 3.5.2.5 and SR 3.5.2.6 These Surveillance demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal (a coincident RWST Level Low-Low signal is required to open the containment sump isolation valves), and that each.ECCS pump starts on receipt of an-actual or simulated SI signal. This-Surveillance is not required for valves that are locked, sealed, or otherwise secured in the
, required Josition under administrative controls. The 18 month Trequency is,bised on the need to perform these
- Surveillance under the conditions that apply during a unit outage and the potential for an unplanned unit transient if the. Surveillance were The 18 month Frequency performed is also with acceptable the on based reactor at power.
consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic L is tested as part of ESF Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program. J O ' i
~BRAIDWOOD - UNITS 1 & 2 B 3.5.2 - 11 6/12/98 Revision A~
t____' . _ _ _ _ _ _ _ . _ _ _ _ _ _ _ . _ . _ _ _ _ _ _ . _ . .
ECCS - Operating B 3.5.2 ( BASES SURVEILLANCE REQUIREMENTS (continued) SR 3.5.2.7 Realignment of valves in the flow path on an SI signal is necessary for proper ECCS performance. .These valves have mechanical stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold legs receive at least the required minimum flow. The 18 month Frequency is based on the same reasons as those stated in SR 3.5.2.5 and SR 3.5.2.6. SR 3.5.2.8 I Periodic inspections of the containment sump suction inlet j ensure that it is unrestricted and stays in proper operating condition. The 18 month Frecuency is based on the need to perform this Surveillance uncer the conditions that a] ply , during a unit outage, on the need to have access to tie ~ l location, and because of the potential for an unalanned transient if the Surveillance were performed wit 1 the reactor at power. This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience. i e I l n ij BRAhDWOOD-UNITS 1&2 B 3.5.2 - 12 6/12/98 Revision A L
ECCS -Operating B 3.5.2 BASES
\I REFERENCES 1. 10 CFR 50, Appendix A, GDC 35.
- 2. 10 CFR 50.46.
- 3. .UFSAR, Section 15.6.5.
- 4. UFSAR, Section 6.2.1.
- 5. NRC Memorandum to V. Stello, Jr., from R. L. Baer,
" Recommended Interim Revisions to LCOs for ECCS Components," December 1. 1975.
- 6. Byron Generating Station Limiting Conditions for Operation Relaxation Program, dated April 1984.
- 7. WCAP-10526 " Limiting Conditions for Operation Relaxation Program."
- 8. NUREG-1002, " Safety Evaluation Report Related to Operation of Braidwood Station Units 1 and 2."
November 1983.
- 9. Safety Evaluation Report, dated January 30, 1998 associated with Braidwood Technical Specification
() Q /- Amendment No. 91.
, (~) '
! \! BRAIDWOOD - UNITS 1 &.2 B 3.5.2 - 13 6/22/98 Revision H l
ECCS - Shutdown B 3.5.3
./O V
B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.3 ECCS- Shutdown BASES BACKGROUND The Background section for Bases 3.5.2 "ECCS-Operating." is applicable to these Bases, with the following . modi fications. In MODE 4, the required ECCS train consists of two separate subsystems: centrifugal charging (high head) and Residual Heat Removal (RHR) (low head). The ECCS flow paths consist of piping, valves, heat exchangers and pumps such that water from the Refueling Water Storage Tank-(RWST) can be injected into the Reactor Coolant System (RCS) following the accidents described in Bases 3.5.2. APPLICABLE The Applicable Safety Analyses section of Bases 3.5.2 also q SAFETY ANALYSES ' applies to this Bases section. Due to the stable conditions associated with operation in . MODE 4 and the reduced 3robability of occurrence of a Design - Basis Accident (DBA), t1e ECCS operational requirements are reduced. It is understood in these reductions that certain automatic Safety Injection (SI) actuation is not available. In this MODE, sufficient time exists for manual actuation of the required ECCS to mitigate the consequences of a DBA. Only one train of ECCS..is required for MODE 4: This
- requirement dictates that single failures 6re not considered !
during this MODE of operation. The ECCS trains satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii). l i I g) L BRAIDWOOD - UNITS 1 & 2 B 3.5.3 - 1 6/12/98 Revision A
ECCS - Shutdown B 3.5.3 BASES LCO In MODE 4. one o.f the two independent (and redundant) ECCS trains is required to be OPERABLE to ensure that sufficient ECCS flow is available to the core following a DBA. In MODE 4. an ECCS train consists of a centrifugal charging subsystem and an RHR subsystem. Each train includes the piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST and transferring suction to the containment sump. 1 During an event requiring ECCS actuation, a flow path is. required to provide an abundant supply of water from the RWST to the KCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to_take its supply from the containment sump and to deliver its flow to the RCS hot and cold legs The LCO is modified by a Note that allows an RHR train to be considered OPERABLE during alignment and operation for decay heat removal, if capable of being manually realigned (remote or local) to the ECCS mode of operation and not otherwise inoperable. This allows operation in the RHR mode during ; ,( MODE 4. APPLICABILITY In MODES 1. 2. and 3 the OPERABILITY requirements for ECCS are covered by LC0 3.5.2. In MODE 4 with RCS temperature below 350 F. one OPERABLE ECCS train is acceptable without single failure consideration, on the basis of the stable reactivity of the
~~
reactor and the limited core cooling requirements. ' In MODES 5 and 6. unit conditions are such that the probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are o addressed by LCO 3.4.7. "RCS Loops-MODE ~5. Loops Filled." and LC0 3.4.8. "RCS Loops-MODE 5. Loops Not Filled." MODE 6 core cooling requirements are addressed by LCO 3.9.5.
" Residual Heat Removal (RHR) and Coolant Circulation-High Water Level." and LC0 3.9.6. " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level . "
L (D U - ( BRAIDWOOD - UNITS 1 & 2 B 3.5.3 - 2 6/12/98 Revision A
ECCS - Shutdown B 3.5.3 O BASES V ACTIONS A.1 With no ECCS RHR subsystem OPERABLE. the unit is not prepared to respond to a loss of coolant accident or to continue a cooldown using the RHR pumps and heat exchangers. The Completion Time of immediately to initiate actions that would restore at least one ECCS RHR subsystem to OPERABLE status ensures that prompt action is taken to restore the required cooling capacity. Normally, in MODE 4. reactor decay heat is removed from the RCS by an RHR loop. If no RHR loop is OPERABLE for this function, reactor decay heat must be removed by some alternate method, such as use of the steam generators. The alternate means of heat removal must continue until the inoperable RHR loop components can be restored to operation so that decay heat removal is continuous. With both RHR pumps and heat exchangers inoperable, it would be unwise to require the unit to go to MOCE 5, where the only available heat removal system is the RHR. Therefore, the appro]riate action is to initiate measures to restore one ECCS RHR subsystem and to continue the actions until the , g subsystem is restored to OPERABLE status, fL1 With no ECCS centrifugal charging subsystem OPERABLE. due to the inoperability of the centrifugal charging pump or flow path from the RWST the unit is not prepared to provide high pressure response to Design Basis Events requiring SI. The 1 hour Completion Time to restore at least one centrifugal charging subsystem to OPERABLE status ensures that prompt action is taken to pro, vide the required cooling ca)acity or to initiate actions to place the unit in MODE 5, w1ere an ECCS train is not required.
.C_1 When the Required Actions of Condition B cannot be completed within the required Completion Time. a controlled shutdown should be initiated. Twenty-four hours is a reasonable time. based on nperating experience. to reach MODE 5 in an orderly manner and without challenging plant systems or
, operators. 1 O ' ! BRAIDWOOD - UNITS 1 & 2 B 3.5.3 - 3 6/12/98 Revision A l t
ECCS - Shutdown B 3.5.3 O BASES
\d
. SURVEILLANCE SR 3.5.3.1 REQUIREMENTS The applicable Surveillance descriptions from Bases 3.5.2 apply.
REFERENCES The applicable references from Bases 3.5.2 apply.
,~
, 't~,/ h L l I i
/ 'T, BRAIDWOCD - UNITS 1 & 2 B 3.5.3 - 4 6/12/98 Revision A t
L RWST i l B 3.5.4 { t-l l(lV B35 EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.4 Refueling Water Storage Tank (RWST) BASES BACKGROUND The RWST supplies borated water to the Chemical and Volume Control System (CVCS) during abnormal operating conditions. to the refueling pool during refueling, and to the ECCS and the Containment Spray System during accident conditions. The RWST supplies both trains of the ECCS and the Containment Spray System through separate, redundant supply i headers during the injection phase of a Loss Of Coolant i Accident (LOCA) recovery. A motor operated isolation valve ! is provided in each header to isolate the RWST from the ECCS once the system has been transferred to the recirculation mode. The recirculation mode is entered when pump suction is transferred to'the containment sump following receipt of the RWST Level-Low Low (LO-2) signal . Use of a single RWST to supply both trains of the ECCS and Containment Spray System is acceptable since the RWST is a 3assive component, and passive failures are not required to )e assumed to occur coincidentally with Design Basis Events. (o-[ The switchover from normal o)eration to the injection phase of ECCS operation requires clanging centrifugal charging pump suction from the CVCS Volume Control Tank (VCT) to the RWST through the use of isolation valves. Each set of isolation valves is interlocked so that the VCT isolation valves will begin to close once the RWST isolation valves
. are fully open. Since the VCT is under pressure. the preferred pump suction will be from the VCT until the tank is isolated. This will_ result in a delay in obtaining ~the i
- RWST borated water. 171e effects of this delay are discussed in the Applicable' Safety Analyses section of these Bases.
During normal operation in MODES 1. 2. and 3. t'e h Safety Injection (SI) and Residual Heat Removal (RHR) pumps are aligned to take suction from the RWST. The ECCS pumps are provided with recircula' tion lines that ensure each pump can maintain minimum flow requirements when operating at or near shutoff head conditions. I. O v BRAIDWOOD - UNITS 1 & 2 B 3.5.4 - 1 6/12/98 Revision A
RWST
, B 3.5.4 - (~) BASES v '
BACKGROUND (continued) When the suction for the ECCS and Containment Spray System pum3s is transferred to the containment sump, the RWST flow patas must be isolated to prevent a release of the containment sump contents to the RWST. which could result in l a release of contaminants to the atmosphere and the eventual - I loss of suction head for the ECCS pumps. 1 This LCO ensures that;
- a. The RWST contains sufficient borated water to support the ECCS during the injection phase: {
- b. Sufficient water volume exists in the containment l sump to support continued operation of the ECCS and Containment Spray System pumps at the time of transfer l
to the recirculation mode of cooling: .
- c. The reactor remains subcritical following a LOCA: and
- d. The RWST contains a sufficient boron concentration to ensure that negative reactivity is available to limit l
.O the. subsequent return to power following a Main Steam i i.y Line Break (MSLB).
Insufficient water in the RWST could result in insufficient cooling capacity when the transfer to the recirculation mode occurs. Impro)er boron concentrations could result in a reduction of slutdown margin or excessive boric acid precipitation in the core following the LOCA. In addition, improper boron concentrations could adversely affect the pH of the sump following the LOCA which can adversely impact iodine concentrations ,for offsite doses stress corrosion
- cracking of eguipment inside containment, and hydrogen production. Finally, improper boron concentrations could adversely affect the pH of the containment spray which can also adversely impact . iodine concentrations for offsite doses (Ref. 1).
L r l 0 BRAI.DWOOD - UNITS 1 & 2 B 3.5.4 - 2 6/12/98 Revision A E
RWST l B 3.5.4 l O BASES
- V l
! APPLICABLE During accident conditions, the RWST. provides a source oi l SAFETY ANALYSES borated water to the ECCS and Containment Spray System pumps. As such, it provides containment cooling and l depressurization. core cooling, and replacement inventory and is a source of negative reactivity for reactor shutdown
- (Refs. 2 and 3). The design basis transients and applicable
- safety analyses concerning each of these systems are .
t discussed in the Applicable Safety Analyses section of B 3.5.2. "ECCS -Operating": B 3.5.3. "ECCS-Shutdown"; and B 3.6.6. " Containment Spray and Cooling Systems." These analyses are used to assess changes to the RWST in order to evaluate their effects in relation to the acceptance limits L in the analyses. The RWST must also meet volume, boron concentration, and temperature requirements for non-LOCA events. The volume is
- not an explicit assumption in non-LOCA events since the required volume is a small fraction of the available volume.
The deliverable volume limit is set by the LOCA and containment analyses. For the RWST. the deliverable volume is different from the total volume contained since, due to the design of the tank, more water can be contained than can ! be delivered. The minimum boron concentration is an l hm explicit assumption in the MSLB analysis and ensures that i negative reactivity is available to limit the subsequent l return to power following an MSLB. The minimum boron concentration limit is also an important assumption in ensuring the reactor remains subcritical following a LOCA. The maximum boron concentration is an explicit assumption in 4 the inadvertent ECCS actuation analysis, although it is typically a nonlimiting event and the results are very insensitive to boron concentrations. The maximum temperature ensures that the amount of coolin~g 3rovided from the RWST during the heatup phase of a feedline areak is consistent with safety analysis assumptions; the minimum is an assumption in both the MSLB and inadvertent ECCS actuation analyses, although the inadvertent ECCS actuation event is typically nonlimiting. O V l BRAIDWOOD'- UNITS 1 & 2 B 3.5.4 - 3 6/12/98 Revision A l l
l l l RWST B 3.5.4 BASES l APPLICABLE SAFETY ANALYSES (continued) l The MSLB analysis has considered a delay associated with the interlock between the VCT and RWST isolation valves. and the results show that the departure from nucleate boiling design basis is met. The delay has been established as~27 seconds, with offsite power available, or 37 seconds without offsite i i power. This response-time includes 2 seconds for ' l electronics delay, a 15 second stroke time for the RWST valves, and a 10 second stroke time for the VCT valves. l For a large break LOCA analysis..the lower boron l concentration limit of 2300 ppm and a conservative l calculation of the minimum RWST volume between the low level setpoint and the low low level setpoint are used to compute ! the post LOCA sump boron concentration necessary to assure l subcriticality. The large break LOCA is the limiting case since the safety analysis assumes that all control rods are out of the core. i The containment analysis and the calculation of the minimum post-LOCA sump pH also use the minimum water volume limit to determine a minimum available RWST volume for calculating fg the time until recirculation for safety injection and containment spray. Finally, the minimum sump flooding (bJ analysis which ensures sufficient Net Positive Suction Head in the sunip for recirculation, uses the minimum water volume limit to determine a minimum available RWST volume. l The upper limit on boron concentration of 2500 pam is used to determine the maximum allowable time to switc1 to hot leg l recirculation following a LOCA. The purpose of switching from cold leg to hot leg injection is to avoid boron precipitation in the core following the accident. l BRAIDWOOD - UNITS 1 & 2 B 3.5.4 - 4 6/12/98 Revision A
RWST j B 3.5.4 I
, BASES j APPLICABLE SAFETY ANALYSES (continued)
In the ECCS analysis, the containment spray temperature is assumed to be equal to the RWST lower temperature limit of l 35 F. If the lower temperature limit is violated, the ! containment spray further reduces containment pressure. The reduced containment pressure lowers the quality of steam l exiting the break thus decreasing the rate which the steam l is vented to the containment atmosphere. The decreased rate l of steam vented to the containment atmosphere results in a corresponding decrease in the rate the Reactor Coolant System pressure drops and the rate ECCS fluid is injected in ' the core thereby causing a rise in peak clad temperature. The upaer temperature limit of 100 F is used in the small break .0CA analysis and containment OPERABILITY analysis. Exceeding this temperature will result in a higher peak clad temperature, because there is less heat transfer from the core to the injected water for the small break LOCA and higher containment pressures due to reduced containment spray cooling ca)acity. For the containment response following an MSL3. the lower limit on boron concentration and the up]er limit on RWST water temperature are used to maximize t1e total energy release to containment. ' n \ k] ( The limits on RWST level and boron concentration also ensure that the post-LOCA sump pH will be between 8.0 and 11.0. The minimum and maximum pH values are verified for each fuel cycle using conservative maximum and minimum RWST volumes and the maximum and minimum allowed RWST boron concentrations. The LOCA offsite dose analysis assumes a conservatively low sump pH for the re-evolution of iodine 4 from the sump. Ensuring that the minimum sump pH is at least 8.0 protects mechanical components and equipment inside containment from_the effects of chloride induced
- stress corrosion cracking. Ensuring that the maximum sump pH is no greater than 11.0 limits the production of hydrogen due to the corrosion of aluminum and zinc inside containment. Finally. the limits on RWST boron concentration also ensure that the containment spray pH is acceptable. The calculation of the iodine removal effectiveness of the containment spray assumes a
. conservatively low containment spray pH.
The RWST satisfies Criterion 3 of 10 CFR 50.36(c)'(2)(ii). l O d ' BRAIDWOOD - UNITS 1 & 2 B 3.5.4 - 5 6/12/98 Revision A l __.________________________-_____.___m
RWST B 3.5.4 BASES (]
^ LCO The RWST ensures that an adequate su) ply of borated water is available to cool and depressurize t1e containment in the event of a Design Basis Accident (DBA), to cool and cover the core in the event of a LOCA. to maintain the reactor subtritical following a DBA, and to ensure adequate level in the containment sump to su) port ECCS and Containment Spray System pump operation in tie recirculation mode To be considered OPERABLE. the RWST must meet the water volume, boron concentration and temperature limits (including vent path) established in the SRs.
APPLICABILITY ~ In MODES 1, 2. 3. and 4. RWST OPERABILITY requirements are dictated by ECCS and Containment Spray System OPERABILITY requirements. Since both the ECCS and the Containment Spray System must be OPERABLE in MODES 1, 2. 3 and 4 the RWST must also be OPERABLE to support their operation. In MODES 5 and 6. the ECCS'and Containment S] ray System are not required to be OPERABLE. Therefore, the RWST is not i recuired to be OPERABLE in MODES 5 and 6 to support the ECCS { anc Containment Spray System. j 0- ACTIONS A.1 l With RWST boron concentration or borated water temperature not within limits, they must be returned to within limits within 8 hours. Under these conditions neither the ECCS nor the Containment Spray System can perform its design function. Therefore. prompt action must be taken to restore the tank to OPERABLE condition. The 8 hour limit to restore the RWST temperature or boron concentration to within limits ! was developed considering the time required to change either ; the boron concentration or temperature and the fact that the l contents of the tank are still available for irjection. l 1 l i
- i
/T U BRAIDWOOD - UNITS 1 & 2 ,
B 3.5.4 - 6 8/3/98 Revision H j l
- - - - - - - - - - - - - - -- - L
.RWST B 3.5.4
~O' BASET V
ACTIONS (continued) g , With the RWST inoperable for reasons other than Condition A (e.g., water volume), it must be restored to OPERABLE status
-within 1 hour In this Condition, neither the ECCS nor the Containment Spray System can perform its-design function. Therefore, prompt action must be taken to restore the tank to OPERABLE
. status or to place the unit in a MODE in which the RWST i.s not required. The short time limit of 1 hour to restore the.
RWST to OPERABLE status is based on this condition simultaneously affecting redundant trains. C.1 and C.2 If the.RWST cannot be returned to OPERABLE status within the-associated Completion Time, the unit must be brought to a MODE in which the LC0 does not apply. To achieve this status .the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 36 hours. The allowed s Completion Times are reasonable, based on operating y experience, to reach the required unit conditions from full power conditions.in an orderly manne'r and without challenging unit. systems. I SURVEILLANCE -SR 3.5.4;1 ! i REQUIREMENTS. ' The RWST borated water temperature should be verified every 24 hours to be within ,tbe limits assumed in the accident ,
- analyses band. This Frequency is sufficient to identify a i temperature change that would approach either limit and has '
been shown to be acceptable'through operating experience. The SR is modified by a Note that eliminates the requirement to perform this Surveillance when ambient air tem)eratures y are within the operating limits of the RWST. Witl ambient , E air temperatures within the band, the RWST temperature ' should not exceed the limits. l- j O ! lBRAI'DWOOD - UNITS 1 & 2- , B 3.5.4 - 7 6/12/98 Revision A __-___,___-__a
i RWST l B 3.5.4 l BASES SURVEILLANCE REQUIREMENTS (continued) SR 3.5.4.2 t Heat traced portions of the RWST vent 3ath should be l verified every 24 hours to be within t1e temperature limit ' needed to prevent ice blockage and subsequent vacuum j formation in the tank during rapid level decreases caused by ' accident conditions. This Frequency is sufficient to identify a temperature change that would ap] roach the lower i limit and has been shown to be acceptable t1 rough operating experience, j The SR is modified by a Note that eliminates the requirement
- to perform this Surveillance when the ambient air temperature is = 35 F. With ambient air temperature above this limit, the RWST vent path will be free of ice blockage.
SR 3.5.4.3 I The RWST water volume should be verified every 7 ' days to be i above the required minimum level of 89% (useable volume of
- > 395,000 gallons) in order to ensure that a sufficient p initial supply is available for injection and to support i
3 J' continued ECCS and Containment Spray System pump operation on recirculation. Since the RWST volume is normally stable and protected by a low level alarm, a 7 day Frequency is appropriate and has been shown to be acceptable through operating experience. SR 3.5.4.4 The boron concentration of the RWST should be verified e' ery ; 7 days to be within thelrequired limits. This SR ensures ; l . - that the reactor will remain subcritical following a LOCA i and will limit the power level increase and subsequently- { returns the reactor to subtritical immediately following an " MSLB. Further, it assures that the resulting sump pH will i be maintained in an acceptable range so that boron precipitation in the core will not occur sufficient iodine
)
will be removed to limit offsite doses, stress corrosion l cracking of equipment will be minimized, and hydrogen i production will be minimized. Since the RWST volume is normally stable, a 7 day sampling Frequency to verify boron l concentration is appropriate and has been shown to be acceptable through operating experience, -l i i l f~) G l BRAIDWOOD - UNITS 1 & 2 B 3.5.4 - 8 6/12/98 Revision A l
RWST
, B 3.5.4 -(N g BASES
- REFERENCES 1. WCAP-13964, Revision 2. " Commonwealth Edison Company, l Byron /Braidwood Units 1 & 2. Increased Steam Generator Tube Plugging / Reduced Thermal Design Flow / Positive Moderator Temperature Coefficient Analysis Program.
I Engineering / Licensing Report." September 1994.
- 2. UFSAR. Chapter 15.
1
- 3. UFSAR, Section 6.2.1.
J i
,P)
U
)
J l l l () l BRAIDWOOD - UNITS 1 & 2 B 3.5.4 - 9 6/12/98 Revision A l
Seal Injection Flow 1 B 3.5.5 l B 3.5' EMERGENCY CORE COOLING SYSTEMS (ECCS) ()'Y
% l B 3.5.5 Seal Injection Flow I l
I BASES l BACKGROUND The function of the seal injection throttle valves during an l accident is similar to the function of the ECCS throttle . valves in that each restricts flow from the centrifugal charging pump header to the Reactor Coolant System (RCS).
)
The restriction on Reactor Coolant Pump (RCP) seal injection flow limits the amount of ECCS flow that would be diverted from the injection path following an accident. This limit is based on safety analysis assumptions that are required because RCP seal injection flow is not isolated during Safety Injection (SI). APPLICABLE All ECCS subsystems are taken credit for in the large SAFETY ANALYSES break Loss Of Coolant Accident (LOCA) at full power (Ref. 1). The centrifugal charging aumps are also credited in the small break LOCA analysis. Tlese two LOCA analyses (n
'd
)
establish the minimum flow for the ECCS pumps. The steam generator tube rupture and main steam line break event-analyses also credit the centrifugal charging pumps. but are not limiting in their design. Reference to these analyses l is made in assessing changes to the Seal Injection System for evaluation of their effects in relation to the acceptance limits in these analyses.
~
L LJ BRAIDWOOD - UNITS 1 & 2 B 3,5.5 - 1 6/12/98 Revision A
l Seal Injection Flow l B 3.5.5 BASES [J' APPLICABLE SAFFTY ANALYSES (continued) This LCO ensures that seal injection flow will be sufficient for RCP seal integrity but limited so that the ECCS trains will be capable of delivering sufficient water to match boiloff rates soon enough to minimize uncovering of the core following a large LOCA. It also ensures that the centrifugal charging pumps will deliver sufficient water for a small LOCA and sufficient boron to maintain the core subcritical. For smaller LOCAs. the charging pumps alone deliver sufficient fluid to overcome the loss and mainta.in RCS inventory. ITS Figure 3.5.5-1 was developed by using a conservative combination of plant data to establish a minimum flow loss coefficient for the seal injection line. Based on the conservative data. Figure 3.5.5-1 ensures adequate flow to the Reactor Coolant Pump seals while ensuring the safety analysis assumption for ECCS flow are maintained. Seal injection flow satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii). LC0 The intent of the LCO limit on seal injection flow is to make sure that flow through the RCP seal water injection l line is low enough to ensure that sufficient centrifugal l . .U charging pump injection flow is directed to the RCS via the injection points (Ref. 2). The LC0 is not strictly a flow limit, but rather a flow limit based on a flow line resistance. In order to establish the proper flow line resistance, a pressure and flow must be known. The flow line resistance is established by adjusting the RCP seal injection flow in the acceptable region of Figure 3.5.5-1 at a given 3ressure differential
- between the charging header and the RCS. The flow limits l established by Figure 3.5.5-1 ensure that the minimum ECCS flow assumed in the safety analyses is maintained.
The limit on seal injection flow must be met to render the ECCS OPERABLE. If this condition is not met, the ECCS flow will not be as assumed in the accident analyses. ( \ v-l- BRAIDWOOD - UNITS 1 & 2 B 3.5.5 - 2 6/12/98 Revision A l
Seal Injection Flow B 3.5.5
.O BASES V
APPLICABILITY In MODES 1. 2. and 3. the seal injection flow limit is dictated by ECCS flow requirements, which are specified for MODES 1, 2. 3. and 4. The seal injection flow limit is not applicable for MODE 4 and lower. however, because high seal injection flow is less critical as a result of the lower initial RCS pressure and decay heat removal requirements in ' these MODES. Therefore. RCP seal injection flow must be - limited in MODES 1. 2. and 3 to ensure adequate ECCS j performance. I ACTIONS A.1 With the seal injection flow exceeding its limit, the amount of charging flow available to the RCS may be reduced. Under this Condition, action must be taken to restore the flow to i below its limit. The operator has 4 hours from the time the i flow is known to be above the limit to correctly position the manual valves and thus be-in compliance with the i accident analysis. The Completion Time minimizes the potential exposure of the plant to a LOCA with insufficient fm injection flow and provides a reasonable time to restore i Q seal injection flow within limits. This time is conservative with respect to the Completion Times of other ECCS LCOs: it is based on operating experience and is sufficient for taking corrective actions by operations personnel. B.1 and B.2 ' When the Required Actions cannot be completed within the required Completion Time, a controlled shutdown must be
. initiated. The Comple' tion Time of 6 hours for reaching MODE 3 from MODE 1 is a reasonable time for a controlled shutdown, based on operating experience and normal cooldown rates, and does not challenge plant safety systems or operators. Continuing the unit shutdown begun in Required Action B.1, an additional 6 hours is a reasonable time, based on operating ex)erience and normal cooldown rates, to reach MODE 4. where tais LCO is no longer applicable.
O O BRAIDWOOD - UNITS 1 & 2 B 3.5.5 - 3 6/12/98 Revision A L_______________________._____ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _
1 Seal Injection Flow B 3.5.5 O BASES U SURVEILLANCE SR 3.5.5.1 REQUIREMENTS l Verification every 31 days that the manual seal injection throttle valves are adjusted to give a flow within the limit ensures that proper manual seal injection throttle valve position, and hence, proper seal injection flow, is maintained. To verify acceptable seal injection flow. the following is performed: differential pressure between the charging header (PT-120) and the RCS is determined and the l seal injection flow is verified to be within the limits of
- Figure 3.5.5-1. The Frequency of 31 days is based on i
engineering judgment and is consistent with other ECCS valve Surveillance Frequencies. The Frequency has proven to be acceptable through operating experience. As noted, the Surveillance is not required to be performed until 4 hours after the RCS pressure has stabilized within a 20 psig range of normal operating pressure. The RCS pressure requirement is specified since this configuration will produce the required pressure conditions necessary to assure that the manual valves are set correctly. The exception is limited to 4 hours to ensure that the q Surveillance is timely. !U REFERENCES 1. UFSAR Chapter 6 and Chapter 15. l 2. 10 CFR 50.46. t > ~~ i m
.b 1 BRAIDWOOD - UNITS 1 & 2 B 3.5.5 - 4 6/12/98 Revision A L
l
. I
Lt o 3.r.I b7 EMERGENCY CORE COOLING SYSTEMS g,g,3,p p.q Ook ohhwa Imt ) SURVEILLANCE REQUIREMENTS (Contint;ek x 3 - JR3.515 mR J.5.14
.cs. % g ,
nn 11 dayV and kithin wurs1//after each solution) g (At least rnnea volume increase of creater than or equal tof&G Eo::au ;Vlby verifying the boron concentration of the accumulator solution. JTEis [ surveillance is not reauired wnen the volume increase makeup source
<> 3 1 1.5 m Iis the RWSTfand the RWST has not been diluted since verifying that the RWST boron concentration is within the accumulator boron
.SA 3.5. l. 6
@g-a-(concentrationlimit,and
, ,, ,-.w At least once g" @
r 31 days [when the RCS pressure i: above 1000-ps+g by verifying that,.he "Et ce periment ter each-acdiniuTitciEfi;oTationF (valve is open :nd t:;ged cut of service.) 4.5.1. Each ccumula r water evel apra press re cnann i shall e demo trated PERABL at least nce p 18 mon hs by th pe'rfor ance of a LA, HA 4EL CAL RATION A LJ a BYRON - UNITS 1 & 2 3/4 5-2 AMENDMENi NO. 82 ! v %g x_-_____-_______- __. . _ _ - _ _ i
l.C0 B Sa2 EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE RE0VfREMENTS 0 4.:.: oach tCCs schsistem s8aii be demonstrated OPra48'c: SR 3.S,1.1
- a. At least once per 12 hours by verifying that the following valves are in the S.1 R.f' position @with powe- to the valve operators removed:
\_,g Valve Number Valve Function Valve Position MOV SI8806 Suction to the SI Open Pumps M0V S!8835 SI Pump Discharge Open*
.. To RCS Cold Legs MOV SI8813 SI Pump Recirculation Open -
To The RWST MOV SI8809A RHR Pump Discharge to Open* RCS Cold Legs MOV SI88098 RHR Pump Discharge to Open* RCS Cold Legs MOV S!8840 RHR Pump Discharge to Closed RCS Hot Legs
. M0V SI8802A SI Pump Discharge to Closed RCS Hot Legs MOV SI88028 SI Pump Discharge to Closed-RCS Hot Legs -
- -h- At least once per 31 days by:
- 1) Vent g the ECCS pump cas gs and discharg pipinghighpoint!
Q ve valves outside of systems only), and tainment (appl able to idle RH an 6 Z/
$*g 3,5,2 ' 2.-3}- Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position @
(applicable to CV, RH, SI systems).
, sca r.wn a 3 Verifyina the T" :v;t='.is'fu11 of water by ultr ontcally
. M 3'5.,7,3-5)- examinin the discharge po ion of the idle CV ump up to the ) ]
discha e check valve, t stagnant portion o the piping upstr as of the SI8801 and B at the 51045 alve, and the - hip g at the CV206 y ve if the B CV pump s idle '(applicable t the CV system on ). I
'c. By visual inspectio which verifies that c loose debris (rags, I ash, clothing, et .) is present in the ontainment which could be l '
ransported to th containment sump an cause restriction of the j pump suctions du ng LOCA conditions. This visual inspection shall
.be performed: /
l Os
, un no4es \k 2-Q Al* valves may be ' - : - A for testing pursuant to Specification 4.4.6.2.2.
U sdakd r
' BYRON - UNITS I & 2 3/4 5-4 AMENDHENT N0.100 <[
racv H !
Lco 3, S. I EMERGENCY CORE COOLING SYSTEMS OA Y sa-t.sa.s em SURVEILLANCE REQUIREMENTS (Continued) rb 7. M 'd'mW heb g 1
/
(m >SR ~5s.t.y cycq y. v 5123.5.14 At leastlonce per 31 dayslandlwithin 6 hoursl4fterjeach solutioni b 5R. 3 5.1.5 tvolume increase of greater than or equa+ to do ac::cn9/by K verifying the boron concentration of the acWmiilit~o r solution. JThisT 3 3 5 1.5 g , / surveillance is not required when the volume increase makeup source
'is the RWST/and the RW51 has not been diluted since verifying tha the RWST boron c~ concentration is within the accumulator boron 3 concentration limit. , _ , _ _ _
4
/ Dower n removed)
SR 3.5 'l . lo
- g. At least oncNer 31 dayver- the RCF ::re::ure i: :bev: 1000 agg' by verifying thatThc .".CC cc:;::rteent--f+r -each-secumda-tm -tschtien f mrtvr .t-open-and-tagged-eut-of-serviced ~,
A LAi
'4 . 5.1/2 Each accumulat~oEsater~levE7 and ~pr ssure c anneT shall be demonstrated OPERABLEl at/ east onc9 / per 18 .onths by/the perfor ance o a
/ CHANNEL CALIBRATION. / / / l
)
i 1 f v M
-d F
BRAIDWOOD - UNITS 1 & 2
~
3/4 5-2 AMENDMENT NO. 74 O ao a l l
L C o 3,f,2. EMERGENCY CORE COOLING SYSTEMS numrzii1ANCE ' REGUim.im:.n i 5 tM Each Eccs subsystem shall be demonstrated CPERABLE: Sit S,%*2..I
-ee At least once per 12 hours by verifying that the following valves are 'in the feedersetedh positio with power to the valve operators removed:- Am Valve Number Valve Function Valve Position NOV 318806 Suction to the SI .open Pumps NOV SISS35 SI Pump Discharge Open*
To RCs cold Legs MOV s18813 SI Pump Recirculation Open To The RWsf.
-NOV sISSO9A RER Pump Discharge to Open*
Rcs cold Legs. Nov s188098' RER Pump Discharge to Open* RCS cold Zags Mov sI8840 RER Pump Discharge to closed RCS Not Legs .
.NOV SIS 802A s!' Pump Discharge to closed Ac5 Not Legs NOV 5188028 sZ Pump Discharge to closed
. Rc5 Not Imgs 4s- At least once per 31 days by: [g 44 ent he Ecca pump casings and discharge piping hi point vent Ives outside of contaignent (applicable to i RE and sI, stems only), and /
.34~ Verifying that each valve (manual, power-operated, or M 3 6*2.L automatic) in the flow path that is not locked, sealed,'or otherwise secured in position 7 is in its correct position (applicable to CV, RE, 31 systems).
QI fECCS p;provy
,34 Verifying the""? :;;'M is full of water /by ultrasonically M 3.5.2.3 emantning ne ossenerge persion erfsne idle cv pump up to e (dischar . check valve, the stagn t portion of the pipi upstr of the sI8801 A and 3 t the 3I045 valve, the i at the icv 207 or 2cV2 valve if the B cv is idle pplicable to the cv sys only).
I fc. a visual inspection wh verifies that no 100 debris (rags, 1
-i trash, clothing, etc.) . present in the conta at which could be transported to the e ainment sump and cause estriction of the
-pump suctions dur IAch conditions. This isual inspection a
~be performed i.co Mes 142. LA:
. l* Valves may be p m M M for testing pursuant to specification 4.4.6.2.2. -
l-isola ded . SRAIDWOOD - UNITS 1 & 2 3/4 5-4 AMENDMENT NO. 91 cy 20 H 4
n DISCUSSION OF CHANGES TO CTS Q ITS SECTION 3.5 ECCS
. ADMINISTRATIVE CHANGES (A) }
A1 All- reformatting.. renumbering, and editorial rewording is in accordance with the Westinghouse Standard Technical Specifications. NUREG-1431. During its development certain wording preferences or English language conventions were adopted. As a result. the Technical Specifications (TS) should be more readily readable, and therefore understandable, by plant operators as well as other users. During this reformatting, renumbering. and rewording process, no technical changes.(either actual or interpretational). to the TS were made unless they were identified and justified.
~
A; -CTS LC0 3.5.1 phrase "Each reactor coolant system accumulator shall be ! OPERABLE" was revised to read "Four ECCS accumulators shall be OPERABLE" consistent with the wording of NUREG-1431. This wording preference does not result in any technical cbmge (either actual or interpretational) to the ITS. This change is c istent with NUREG-1431. A3 (Byron Only) The CTS footnote #, footnote **. and the associated LC0 3.5.1.c.2 requirement denoting theThe apfor particular deleted boron cycles have been dele concentration requirement applied to previous fuel cycles and is no
' longer. applicable to operation of the units. The change ~is editorial in nature and does not involve a technical change (either actual or
_- -interpretational) to the TS. This change is consistent with NUREG-1431.
'(Braidwood Only) The CTS footnote #. footnote **. and the associated
-LCO 3.5.1.c.1 requirement denoting the applicable boron concentration .
for particular cycles have been deleted. The deleted boron concentration requirement applied to previous fuel cycles and is no longer applicable to operation of the units. The change is editorial in nature and does not-involve'a technical change (either actual or interpretational) to the TS. This change is consistent with NUREG-1431. i BYRON /BRAIDWOOD UNITS 1 & 2 '3.5 1 7/9/98 Revision A
DISCUSSION O'F CHANGES TO CTS' ITS SECTION 3.5 ECCS l A, ; The' CTS footnote
- m6difying the Applicability'of. the LCO in Mode 3 has
-been deleted and the associated requirement moved to the Applicability.
Also-footnote
- was changed from " Pressurizer Pressure" to "RCS
-Pressure." , Pressurizer Pressure is equivalent to RCS Pressure and.
therefore, this change is- an editorial change. The CTS SR 4.5.1.1.c was also. revised deleting < the phrase "when the RCS pressure.is above 1000 psig". consistent with the footnote
- requirement being moved to the; l Applicability. '.The Ap)licability is being revised only to clarify the actual Mode of Applica)ility for the LCO. With this requirement denoted in~.the Applicability. no other references'are necessary nor required.
nThe-changes are-editorial in nature and do not involve-a technical change (either actual or interpretational) to the TS. This change is consistent with NUREG-1431 as-revised by an approved generic change-(TSTF-117), L I l0 i -- i
+
- BYRON /BRAIDWOOD UNITS 1 & 2 3.5 la 6/22/98 Revision H
.h..
~
L DISCUSSION'0F CHANGES TO CTS L ITS SECTION 3.5 ECCS h Aj CTS SR 4.5.1.1.b requires the accumulators be sam increase of greater than or equal.-to 70 gallons.Currently, pled after each volume when
]
filling the accumulators per. the _ operating procedures the accumulators are conservatively required to be sampled after each fill to ensure compliance with this SR. ITS SR 3.5.1.5 will require verifying.the boron. concentration of the. accumulator ~ solution once within 6 hours < 'after each solution volume increase of greater than or equal to 10% of indicated level which is equivalent to 70 gallons. . The nominal water . L volume of the SI Accumulators is 7106 gallons based on the minimum'and maximum volumes of 6995 gallons at 31% indicated level (low level alarm) = 5 and 7217 gallons at 63%: indicated level (high level alarm). This. change J. in volume is equal to.222 gallons over a 32% level span or approximately y 7' gallons per % level. change; The 0% level: equivalent is 6781 gallons 1 o and the 100% level indication is 7466 gallons equaling a total change of-
'685 gallons over the.100% indicated level span or 6.85 gallons per %
level ~ change. This would_ equal a 10;2% indicated level increase for a !- '70 gallon volume increase in the SI Accumulator. The expression for volume has been changed.from. gallons to an equivalent percent indicated level to be consistent with the indication available to the operator and the manner in which the increase in volume is verified. This change is perceived as' the intent of the CTS wording. is considered editorial in nature and does not. involve a technical change (either actual or interpretational) to the TS. This change is consistent with NUREG-1431. A, CTS SR 4.5.1.1.c provides an explicit- detail on how power is removed T from the accumulators' discharge. isolation valves by verifying that the 3 . MCC compartment is open and tagged out .of service. .ITS SR 3.5.16 states only that power be removed to:the discharge isolation valves. The CTS has been revised to replace the explicit details on how to perform.the SR. This change is perceived as the intent of the CTS wording. -is. considered editorial in nature'and does not involve a technical change _(either actual'or interpretational) to the TS. This
- change is consistent with NUREG-1431.
~
A, LNot used.- - Ag ' CTS SR'4i5;2 a has been revised to replaced the word " indicated" with the word " listed" to eliminate a discrepancy in the literal meaning of the word. The word " indicated":could infer actual indication in the control-room rather than the positions indicated or pointed.out from a ilisting of valves denoted in the-surveillance. This change is perceived as the. intent of the CTS wording. .is considered editorial in nature and
. .does not-involve a technical change (either actual or interpretational) to the TS. This change is consistent ~with NUREG-1431.
l u !. BYRON /BRAIDWOOD 'JNITS'1 & 2 3.5 3 6/22/98 Revision H 'h e ,
u . DISCUSSION OF CHANGES TO CTS ITS SECTION-3.5 ECCS-
;O -
J^;i \wot useo .
- A M .Not'used.
?
)
, , , ,~
l
..d D
l
' ht t'1 4
R k 5 I
.- BYRON /BRAIDWOOD : UNITS 1.& 2:
. . 3.5 3a 6/22/98 Revision H O.
':' G 4 . 4
i I DISCUSSION OF CHANGES TO CTS
.ITS SECTION 3.5 ECCS
{ j h? N LAo CTS.LCO 3.5.2' footnote
- requires the accumulators to be Operable ~ during.
Mode 3 with pressurizer pressure < 1000.psig whenever isolation valves SI8809A or SI8809B are closed This requirement is to be relocated to Ml the Bases.' This requirement provides assurance that the accumulators 4 would be available for cold leg injection during the performance of
. =. check valve leakage tests required in CTS SR 4.4.6.2.2.
CTS SR 4.4.6.2.2. requires check' valves SI8818A. .B.- C. and -D (located in the cold leg injection. lines)lbe checked for back leakage into the RHR System during Mode 3 at certain intervals. Closing either isolation valve SI8809A or SI8809B to perform check valve leakage tests on valves SI8818A. B. C. and D. results in isolating cold leg injection flow paths. The establishment of accumulator Operability during this condition'is'not important provided an alternate.means of assuring cold leg injection is established during this test. Note 2 to ITS LCO 3.5.2 allows isolation of both RHR System flow paths for up to 2 hours for pressure isolation valve testing in Mode 3 provided alternate means of g, cold ~1eg injection is available for each isolated flow path. As such. N .the detail associated with assuring cold leg injection is available is
'1 - not- required to be in TS to ensure adequate protection of the public y : health and safety. Any change to the Bases will be made in accordance c). with the Bases Control Program described in ITS Section 5.5.
- LAf CTS SR 4.5.2.b.1) and b.3) as well as the Operating License. Appendix C
. license condition, provide details describing the methods used to ensure that the ECCS piping is full of water. These details are relocated to A the ITS Bases. These details are not necessary to ensure the V Operability of the ECCS. The requirements of ITS LC0 3.5.2'and the associated Surveillance Requirements are adecuate to ensure the ECCS are maintained Operable, As a result, the methocs of performing Surveillance are not necessary to ensure the ECCS.can perform their intended safety function and the details are not required to be in the
- l. TS or license condition to provide adequate protection of the public health and. safety. The relocation of these details maintains consistency with NUREG-1431. Any ~ change to these details will be made in.accordance with the Bases Contro'l Program described-in ITS Section 5.5.
p
' BYRON /BRAIDW000 < UNITS 1 & 2 -3.5 10 6/22/98 Revision H
%)
L__ _ _- _=
i i DISCUSSION OF CHANGES TO CTS
. ITS SECTION 3.5 ECCS p L, CTS LCO 3.4.6.2 requires the Applicability of the seal injection flow Q- _ requirements in Modes 1. 2. 3. and 4. In addition the LCO and SR references various conditions for exiting the Mode of Applicability and exceptions to Specification 4.0.4 for entry into Mode 3 and 4. ITS LC0 3.5.5 requires the Applicability of the seal injection flow requirements in Modes 1. 2. and 3. The CTS has been revised to eliminate the Mode 4 seal injection flow requirements. This change is acce3 table since high seal injection flow is less critical as a result of t1e lower initial RCS pressure and decay heat removal requirements in Mode 4. In Modes 1. 2. and 3. the seal injection flow limit is dictated by'ECCS flow requirements. Therefore. RCP seal injection flow is j limited in Modes.1. 2. and 3 to ensure adequate ECCS performance and a changing the Mode of Applicability is acceptable. Changing the L1 A3 placability to Modes 1. 2. and 3 changed ~the Completion Time to exit 0 t1e Mode of Applicability from 30 hours to be in Mode 5 to'12 hour 3 to
.g be in Mode 4. The Com31etion Time of 12 hours to be in Mode 4 is consistent with both tie CTS and the ITS Completion Times used
'k4 throughout the specifications for placing the unit in Mode 4. including LCO 3.0.3. This change is consistent with NUREG-1431. See Discussion of Change M 2 for discussion of the Mode 3. 4.0.4 exception.
L, CTS SR 4.5.2.e.1 and 4.5.2.e.2 requires verification that each automatic valve actuates to its correct position or each ECCS pump automatically starts on a test signal. ITS SR 3.5.2.5'and SR 3.5.2.6 requires verification that each automatic valve act~uates to its correct position A or each ECCS pump automatically starts on an actual or simulated V actuation signal. The CTS has been revised to add the allowance to demonstrate these surveillance with an actual or simulated signal. This change is acceptable since the function is demonstrated. The type of signal generated to demonstrate the function is irrelevant to the acceptance of the performance of the function. This change is consistent with NUREG-1431. Along with this, the CTS has been revised to delete the phrase "during shutdown.". consistent with NUREG-1T31. Such limitations are not required to be detailed in the Technical Specifications. These SRs are typically performed during plant shutdown. However, if for instance, an actual signal is generated while operating, results should be useable i even though the plant is not " shutdown". Similarly, if testing would be 1 required to complete some repair or modification made while operating a shutdown should not be required. Therefore, the deletion of the limitation more accurately reflects the intent and allows for the utility to schedule testing more appropriately.
.n BYRON /BRAIDWOOD UNITS 1 & 2 3.5 18 6/22/98 Revision H U -
I l
Accumulators 3.5.1 l 3.5. EMERGENCY CORE C00 LING SYSTEMS'(ECCS)'
~^
L" "3.5.1~ Accumulators
- LCO 3.5.1 MFour ECCS accumulators- shall be OPERABLE. A
-__-n 3 p
,m
; APPLICABILITY:
. MODES:1 and 2,- y e G MODE 3 with e" .__/ . pressure p1000]'psig.
p [ l<- 'ACTIONSL CONDITION: REQUIRED ACTION COMPLETION TIME
-A.- One accumulator- A.'1 Restore boron 72 hour's inoperable.due to concentration to.
', boron concentration 'within limits. not withinflimits.
~
B. .One accumulator: B.1 Restore accumulator: I hour-
-l ^ . inoperable,for reasons to OPERABLE status.
'other than-
~
, . Condition A.
. l C.: Require'dl Action and' C.1 - Be in MODE 3.- 6' hours
' associated Completion . _
L Time of Condition'A MNQ .. . Lor B'not' met. .. . RcsI C C.2 .ReduceI P ""-u:d. 12 hours-pressure to. ( , sg1000Tpsig. l D.- Two or more-. D;1- Enter LCO 3.0.3... Inunediately
- accumulators inoperable.
lCe p MWOG STS- 3.5-1 Rev 1, 04/07/95.' 4
.RiN %
ccu -_= =_-
i l JUSTIFICATIONS FOR DIFFERENCES ~TO NUREG 1431 LCOS
- SECTION 3.5~ .ECCS-h GENERIC CHANGES
.C( :This change is consistent with.NUREG-1431..as modified by TSTF-90 (NRC -
approved). TSTF-90 included-the deletion of some of the ECCS-Operating-SRs: from the list oflSRs which are applicable to ECCS-Shutdown. Consistent with CTS these SRs are retained. In addition, the Note which
-is moved and Condition .A are editorially rev.ised to define ~ RHR at the
; $ ._ first usage.
m . TC 2 Not used. C-3' LThis change is consistent .with NUREG-1431. .as modified by TSTF-153 (NRC
' proved). -The bracketed information contained in Note 2.is deleted due so plant specific requirements as described in-B3 .
C, ~ -- This change is' consistent with NUREG-1431, as modified by' STF-117' (NRC approved). Plant .s)ecific modifications .to the changes proposed _in
'TSTF-117 are descri Jed -in P3 .
O e t v p x ~ BYRON /BRAIDWOOD ' UNITS 1 & 2 3.5 2 6/22/98 Revision H ( ):
.%s:
4 .
?
m.m._____._ _ _ _ _ . _ ._...m_ _ _ _ _ _ _ ._ __ _ _ _ _ _ . . m_ _. _ _ _ _ _ _ _ _ . _ _ . _ _ _ _ _ . _ _ _ _ . _ _ _ . _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ .
L h . BASES INSERT (S) SECTION 3.5 Bases 3.5.2 I [ INSERTB 3.514Ai (Ciand Pn)
-l The LCO is modified by two Notes'.that allow isolation of. both SI pump flow: paths and a portion of both RHR flow paths. for up to 2 hours-to perform pressure isolation valve testing Jer SR 3.4.14.1.during MODE 3.
-Isolation ~ of the discharge flow paths of )oth SI . pumps may be
, accomplished by: closing-valve S18835. . I. solation of a portion.of the. .;'
' discharge flow paths of both RHR pumps may be' accomplished by closing
.. either. valve SI8809A or SI88098. With a portion of both RHR flow paths VN isolated.can alternate means of' cold leg injection must be available for each isolated flow 3ath. . An. alternate means may include: 1) OPERABLE d4 < accumulators with t1eir isolation valves either closed, but. energized, pi ?or open: 2) cold leg injection'via'the Safety Injection pumps, and.the SI8821A/B and the SI8835 valves; or 3) cold leg'. injection via the Centrifugal: Charging pumps'and the SI8801A/B valves.
k i
.; A ?
k
^
, i A
.}-..
H' . L %.J M 6/22/98 Revision H i g -
. ~.7 ), - i lQ:l
ECCS-Operating B 3.5.2
+
BASES) 1 M> JACTIONS-g -
- ' @c,
' c.
l and @ 2 (continued)hIf the[ inoperable trains! cannot be returned .to OPERABL e' h status lwithin'the. associated Completion Time, the be brought'to~a MODE in which the LCO does not' apply. must To achieve this status,: the es:em, must.. De Drou within 6 hours and MODE 4 within 12 hours. gnt Thetoallowet: riout Completion. Times are reasonable, based on operating-experience, to reach the requirediomsiconditions- from fuW ! power conditions in an orderly manner and without I challenging plant systems. [u M l SURVEILLANCE- SR 3.5.2.1-
. REQUIREMENTS ab ' **h 4 6M*'9 Verification of proper valve position' ensures that thelflow ' '
_ path from the ECCS pumps to the'RCS.is~ maintained.
-{
Misalignment. of these valves could. render both ECCS trains
'. inoperable. Securing these' valves in position by removal of
"> power r b".h " 10th'n; th :::trr!
4 ensures t it~diey cannot. change position as a result' of an" the
. active failure or be inadvertently mis ' ned.- These valve's n 1, .are of;the. type,. described in Referenc
- that can disable L'- ~
the function of both ECCS trains and inva ,idate the accident-analyses'. 'A.12 hour Frequency is considered reasonable in-view of other administrative controls.that will. ensure a mispositioned valve is'unlikely. SR 3.5.2.2 l e.1 i he aim lL4ed 'm 5e. 3.5.1.1 ( g sa 3,5,2, i.
/ Verifying.the correct 'Tignmenta for manual,: power operated, and automatic valves in.the ECCS. flow paths:provides
; assurance that theiproper flow paths will exist for ECCS
-operation ~ ~This-SR does not apply to valves that are
_gc.
. locked, sealed, o_r 'otherwise secured in position >, since these were; verified to be in'the correct position prior to
~
locking, sealing, or securing.. A valve that receives an ' R, actuation'signaltis' allowed to be in a nonaccident position provided the valve will.automatica1.ly reposition within the E proper stroke time. This. Surveillance does not: require any
' ~
testing or' valve manipulation ~. Rather, it' involves j verification. that those valves capable- of. being mispositioned are.in-the correct position. .The 31 day Frequency is appropriate because the valves are operated 1 (continued) 9WOG STS. B 3.5-17 Rev 1, 04/07/95 / j k, (2m k e l
ECCS-Operating 8 3.5.2 BASES f)
'v SURVEILLANCE SR 3.5.2.2 (continued)
. REQUIREMENTS under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating ' experience.
4 5m *M l SR 3.5.2.3 e M em pit peni3, v.c3 71D g% With the exception of the operating centrifugal charging pump, the ECCS pumps are normally in a standby, nonoperating
' 3 m de. As such, flow path piping has the potential to-Cb re*ah5 *#
P99 erto.nwegzzs develop u_ _m__ voids m__ and u_ pockets of entrained gases,., M: int:ining
,~.,_.____u_ m-,
y,, w, we W.cs mu,,, '" _ 1 " T ".?.m._ P, TT. . _ "._.'., ._. !. .:..T. . ..'.".."r_
. "r_". _17.
.!!r _ ,'l. .,' ,' 71_Z !. !. ,',,_
W> m m.... , . u. ._ 5
' 2 full apnity int; th: ".05 up:n dc= nd. This will also prevent water hammer, pump cavitation, and pumping of g noncondensible gas (e.g., air, nitrogen, or hydrogen) into the reactor vessel following an SI signal or during shutdown (L*rb M.s-tea) coolingv. The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation.
SR 3.5.2.4 Periodic surveillance testing of ECCS pumps to detect gross degradation caused by impeller structural damage or other hydraulic component problems is required by Section XI of the ASME Code. This type of testing may be accomplished by
~
measuring the pump developed head at only one point of the pump characteristic curve. This verifies both that the measured performance is within an acceptable tolerance of
, the original pump baseTine performance and that the performance at the test flow is greater than or equal to the performance assumed in the plant safety analysis. SRs are specified in the Inservice Testing Program, whi'ch.
encompasses Section XI of the ASME Code.. Section XI of the ASME Code provides the activities and Frequencies necessary to satisfy the requirements. - SR 3.5.2.5 and SR 3.5.2.6 These Surveillance demonstrate that each automatic ECCS ! valve actuates to the required position on an actual or (continued) R-U 'WOG STS B 3.5-18 Rev 1, 04/07/95 L l7 2CV H l
BASES INSERT (S) - SECTION 3.5 lh-J: Byron Specification Bases 3.5.2 INSERT'B 3.5 18A ~(Pa)
.This is accomplished by venting the non-0)erating ECCS pump casings and
~the discharge piping high points (applica)le to idle RH and SI systems only) outsi.de containment to maintain the ECCS piping full of water.
In the event that gas is present at'either RH cold leg isolation valve
'(SI8809A/B). vent valve (SIO58A/B). the three gas traps associated with the ECCS crossover piping will'be UT inspected to confirm the pip.ing is full of water. SR 3.5.2.3. requires that the RH and SI pump casings and ;
discharge piping high point vent valves be vented. This venting surveillance does not apply to subsystems in communication with
. operating systems because the flows in these systems are sufficient to provide confidence that water hammer which could occur from voiding would not resultLin unacceptable' dynamic 1oads. During shutdown cooling operation, the exclusion would apply ~to the operating RH pump. in addition to the.ECCS piping in communication with the operating pump.
For selected portions of piping (i.e.. Jortions involving the idle CV pump discharge piping up to the first cleck valve on the pump discharge
.and miniflow lines. the stagnant portion of the piping upstream of the
. . . SI8801A/B adjacent to the vent valve SIO45. and the piping at the CV206 valve if the B CV pump is -idle) the verification that the piping is filled with water will be-performed by ultrasonic examination. this examination will 3rovide added assurance that the piping is water- i solid. These metlods are consistent with Reference 9. l
)
l I 6/22/98 Revision H. i O- - l w___ _m__ _ __ _ _ _ _ _ - - - - - - ~ - - - - - - - - - - - - - - - - - - - - - --- - ------ - -------- - - - - - - - - - -----=-----J
BASES INSERT (S) ' SECTION 3.5 O>1 Braidwood Specification Bases 3.5.2 ' INSERT B 3.518A - (P3 ) I 1
-i This-is accomplished by venting the non_--o)erating ECCS pump casings and ;
the discharge piping high points (applica)le to idle RH and SI systems only).outside containment to maintain the-ECCS piping full of water. . In the event.that-gas-is present at either RH cold leg isolation valve
.(SI8809A/B) vent valve'(SIO58A/B), the three gas traps associated with the ECCS crossover piping will be UT inspected to confirm the piping is full of water. SR 3.5.2.3 requires that the RH and SI pump casings and
, discharge piping high. point vent valves be vented. This venting-surveillance does not apply to subsystems in communication with
. operating systems because the flows in these systems are sufficient to :
provide confidence that water hammer which could occur from voiding l would not result in unacceptable dynamic 1.oads. During shutdown cooling ' operation. the exclusion would apply to the operating RH pump. in ; addition'to.the-ECCS piping in communication with the operating pump. For selected portions of piping (i.e.. aortions involving the idle CV pump _ discharge piping up to the first cleck valve on the pump discharge and.miniflow lines. the stagnant portion of.the p ping upstream of the SI8801A/B ad acent to the vent valve SIO45, and t e piping at the 1CV207 A. or 2CV206 va ve if the B CV pump is idle) the verification that- the Q piping is filled with water will be performed by ultrasonic examination. this examination will provide added assurance.that the piping is water solid. These methods are consistent with Reference 9. 4 l i u-1 i 6/22/98 Revision H D-O . L l.p i [.
f --- , - m ~. ,, \ 7 h()a / h rt w h uu A m o n R w h m i ECCS- perating
* * * ^ " ' '
- knen ( 64A%oh 3.5.2 \
h b".Unin i ud L Olo vende r Ic)?M. , Feb rua rq19 82. -
\
1 BASES (continued) W U! REFERENCES 1, 10 CFR 50,. Appendix A, GDC 35.
- 2. 10 CFR 50.46.
h 3.hAR,Section 'I
.Q;4. hAR,Anapter[15], "A::id:nt Analysis."' SecL L 2.1.
'5. NRC Memorandum to V. Stello, Jr., from R.L. Baer,
. Recommended Interim Revisions to LCOs for ECCS Components," December;.1, 1975.
-+
I E In ivi iii.t l un Nuiluu Nv. 07-01. g, v>ym c,meca g s t- A q s a - s\ i Ar cyrm o s kirx o% sos\+e gmwy detA i W\ \ %2A . n
,- W Q.h!Q-\DCbb, '
. M '- .
O N om, n w sa~ w: ~
oeg>T. &NN Evutuoh6 Repx4 d=4es L oaty % \vtB
/~
lQ' . cfrJa aswom,,wm % w _s.s-nmmm 3 fq Am*^be flo. ; m. [
~;
MICIWDQ D i 8 W b- N b\t.A f4 n NET, D D bI'M 8 g o ^' ' 9aouwnm unin seasocoon hm.au Sunwmn Q. Ame^N rW O..N I . t l<
+ .
( WOG STS B 3.5-20 Rev 1, 04/07/95' WH a- -_ _
~ _
BASES INSERT (S) SECTION 3.5 g a kJ"' $ Bases 3.5.4 INSERT'B 1 5 28A :(P3 )
~
.,The reduced co'ntainment pressure-lowers the quality. of steam exiting ~the
- break thus decreasing the rate which the steam is vented.to the containment atmosphere. The decreased rate of steam vented to the.
containment-atmosphere results in a corresponding decrease in the rate the Reactor. Coolant System pressure drops and the rate ECCS fluid is-
. injected .in'the core-thereby causing a rise in peak . clad temperature.
'INSERTB3.5288~.'(Ps);
*The limits on ~RWST;1evel and boron concentration also ensure that' the post-LOCAl sump pH.will be between 8.0 and 11.0. The minimum and maximum L: pH values are verified for each fuel cycle using conservative maximum -
and minimum RWST volumes.and the maximum and minimum allowed RWST boron.
- concentrations. The LOCA offsite dose analysis assumes a conservatively low sump pH for the re-evolution of iodine from the sump. Ensuring that
_ 1the minimum sump pH is at least 8.0 protects mechanical components and:
.fM '
,equipmentninside' containment from the effects-of chloride induced stress
! corrosion' cracking.. Ensuring that the maximum sump JH is no greater-than 11.0f limits the production of hydrogen due to tle corrosion' of.
aluminum and zinc inside containment. Finally..the limits on RWST boron concentration also. ensure that the' containment _ spray pHii_s~ acceptable. (The calculation of the: iodine ~ removal effectiveness of the containment [
+
spray assumes;a conservatively low containment spray'pH. p - t _ e
, , 4
' INSERT B 3.5-28C - (P3 ). l
+
- In MODES 5-~and 6 the ECCS and Containment Spray System are not-required
'to be OPERABLE., . Therefore.- .the RWST is not required to be OPERABLE in 4 .MODESs5;and;6 to, support the.ECCS and Containment Spray System.
.a 3:
t gg , 6/22/98 Revision H AJ ' t , , l- &_i. " " ~ . . - .
- 1. _ _ _ _ _ _ _ _ _ _ _ __ _ . _ ._ _ __ __
_1________.._,__ ________._____J
~ JUSTIFICATIONS FOR DIFFERENCES TO NUREG 1431 BASES SECTION 3.5 - ECCS
BRACKETED CHANGES B3 The brackets were. removed and plant specific values. descriptions, or nomenclature were.added.
. GENERIC CHANGES
.Ci This change is consistent with NUREG-1431. as'. modified by TSTF-90 (NRC a) proved). ..TSTF-90 included the deletion of some of the ECCS-Operating Sts'from.the list of SRs which are applicable-to.ECCS-Shutdown.
-Consistent with. CTS these SRs are retained; This change to Reference'10 CFR 50.36(c)(2)(ii), is consistent with
~
Cf NUREG-1431. as modified by an editorial change submitted to and approved by the..NRC.
-C 3 . This: change. is consistent with NUREG-1431_as modified by TSTF-153 (NRC
. approved). The bracketed information contained in Note 2 is deleted due to plant. specific requirements as described in Pn and Pn..
C, This change .is consistent with. NUREG-1431. as modified by;TSTF-117 (NRC approved). Plant s)ecific modifications.to the changes proposed in TSTF-117 are descri aed in P4 .
; ,m .
N_)
.1
~
9 4 E. m BYRON /BRAIDWOOD - UNITS 1 & 2 3.5 1 6/29/98 Revision H _-.m( ). i r , e { _i..._._-_.l.. - - - _ . - . - - . - . - . - - - - - - - . - - - - - - - - - - - - - - --- -- - - - - - - -- -- - ^ - ' - - ' ^ '^
' JUSTIFICATIONS FOR DIFFERENCES TO NUREG 1431 BASES SECTION 3.5 ECCS 1: Pu
.NUREG Note 2 of LC0 3.5.2 and' associated Bases were deleted since
-certain ECCS Jumps are rendered inoperable when any RCS cold leg is at or below 330".;which is representative of Mode 4 conditions. This is
. consistent with the CTS and current licensing basis.
Pu Condition A for-ITS LC0 3.5.2 and associated Bases were revised and subsequent. Conditions renumbered to denote two separate Conditions
'(Conditions A and B). The new Condition A allows one train of ECCS to .
be inoperable.for up'.to 7 days. This additional allowance was based on the limiting Conditions for Operation Relaxation Program as documented
.in WCAP-10526. This allowable outage time relaxation was approved by-the NRC in a SER dated January 21.- 1988 for.both stations. The new
. Condition B allows two trains of ECCS to be inoperable for up.to 72 hours provided at least 100% of the ECCS flow equivalent to a single i operable ECCS train is available. The requirements specified in this 1 Condition are consistent- with the NUREG for a two train inoperability, i
. Additionally. the subsequent Conditions were renumbered. Condition A for ITS 3.5.4 is consistent with the requirements of CTS Action 3.5.2.a 1 and has been retained based on current licensing basis. Actions Bases !
are revised to delete the reference to the " generic" analysis. Since - l plant specific. references are provided. j Pu The Bases for SR 3.5.2.1' was-revised to delete the method for securing ECCS valves. .The method of key locking the control in the_ correct position is not used. These valves are controlled by the removal of power to the motor operator. P- 3 The Bases for SR 3.5.2.3 was revised to add details from the CTS and license condition describing th.e method for ensuring that the ECCS
. piping is maintained full of water.
P a' The Bases for SR 3.5.2.5 and SR 3.5.-2.6 were revised to add details from the CTS describin the Surveillance.g the Thesimulated signals auto-opening requiredsump _ containment for the performance suction valves of require a coincident RWST Low-Low Level si.gnal.
-P p. The Bases for. LCO 3.5.4 has been revised to clarify the specific ,
analysis appli'ed to the RWST. For a - full sized MSLB at hot zero power., the doppler power coefficient limits the 3eak power reached in the short term' following the initiation of the breac. However, following that initial peak in power. borated water from the RWST delivered by the ECCS
- system limits the subsequent return to power. This design feature also eliminates-the requirements for the Boron Injection Tank (NUREG LC0 3.5.6 and Bases deleted). This change also ensures consistency.
between ECCS Bases safety analyses-descriptions by providing information
'on other events the system is assumed to mitigate such as the Main Steam Line Break event.
BYRON /BRAIDWOOD UNITS l'& 2 3.5 4 6/22/98 Revision H }}. . . l
JUSTIFICATIONS FOR DIFFERENCES TO NUREG-1431 BASES SECTION 3.5 ECCS P;
' k'] u The Bases for LCO 3.5.5.1 have'been revis' seal-injection flow is found on a gra)h. The re uirement maintains the e d to specify the allowable .
requirement to maintain flow within tie limits o -the ECCS safety analysis; In addition. since the differential pressure takes into
. account the 3ressure drop associated with the seal water injection piping'and tie flow control valves, the requirement for the position of the flow control valve as specified in NUREG-1431 does not apply. See Discussion Of Changes L..
.P3 The ITS LC0 3.5.4 Bases have been revised to eliminate the statement
. "and Containment Spray System." to reflect the Byron and Braidwood design. This change is consistent.with UFSAR Section 6.2.5.1 design.
description. P3 NUREG Bases 3.5.2 Reference 6 (ITS Reference 8).was revised'by referencing an NRC SER specifically issued to Byron /Braidwood on the issue of concern instead of generic IE Information Notice No. 87-01. O i BYRON /BRAI'DWOOD UNITS 1 & 2 3.5 6 6/22/98 Revis1on H
.}}