ML20035H369
| ML20035H369 | |
| Person / Time | |
|---|---|
| Site: | 05200001 |
| Issue date: | 04/28/1993 |
| From: | GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20035H367 | List: |
| References | |
| NUDOCS 9305040332 | |
| Download: ML20035H369 (10) | |
Text
AFF 28 "93 09:37A1 G E f u1EM DLIG J P.2/10
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Control Rod Scram Accumulators 3.1.5 3.1 REACTIVITY CONTROL SYSTEMS 3.1.5 Control Rod Scram Accumulators 4
LCO 3.1.5 Each control rod scram accumulator shall be OPERABLE.
APPLICABILITY:
MODES I and 2.
ACTIONS
NOTE-------------------------------------
Separate Condition entry is allowed for each control rod scram accumulator.
CONDITION REQUIRED ACTION COMPLETION TIME l
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A.
One control rod scram l A.1
NOTE--------
accumulator inoperable, Only applicable if
_ -ith rced m deam the associated
-dcmc y. o m e control rod scram
[^00] p5i s time was within the f
2 limits of Table 3.1.4-1 during the last scram time i
Surveillance.
Declare the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> associated control rod scram time
" slow."
l Of i
A.f Declare the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> i
associated control rod inoperable, oyto.s+<olrod fair i
(continued) i
-BWWfr STS 3.1-16 Rev.
O, 09/28/92 A8ug
.$850$00S$ N$hi 0
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AFlP 28 '93 09:38A!1 G E f D' LEAR BLIG J P.3/10 I
k Control Rod Scram Accumulators 3.1.5 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME
(_
B.
Two or more control B.1 Restore charging 20 minutes from rod scram accumulators
{
water header pressure discovery of i no p e rabl e.-w+4h-g to e [1520] psig.
Condition B
-roarter sit = k d I
concurrent with
-pretsm c i- [200] g5it, charging water header ressure f
< [1520 psig E!Lo B.2.1
NOTE---------
Only applicable if the associated control rod scram time was within the limits of Table 3.1.4-1 during the last scram time Surveillance.
)
l Declare the I hour associated control rod scram time
" slow."
-fhhP Declare the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> g,4 associated control rod inoperable.
.5 One or moi"exont. col C.1 Verify all c trol Immediately upon rod scram accumulatoYs~
rods a ated with discovery of inoperable with Grable charging water reactor steam dome accuT: ink re header ressure pressure <
.sif fully insert
< [1520 psig x
AND
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-Q ontinue i
A BWRf6 STS 3.1-17 Rev.
O, 09/28/92
r fER 2B '93 09:3EW1 G E HUCLEi4? ELEG J P. v10
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Control Rod Scram Accumulators 3.1.5 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A
Wtom."" d C.2 Declare the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> ed control d
rod inope C -
- f. Required Action and
[.1
-NOTE---------
c associated Completion c
Not applicable if all Time not met, inoperable control rod scram accumulators are associated with fully inserted control rods.
Place the reactor Innediately mode switch in the shutdown position.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY
.j SR 3.1.5.1 Verify each control rod scram accumulator -
7 days pressure is a -[1520] prir t
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R 9 28 '93 09:3%M G E tiLCLEAR DLDG J P.5/10 Control Rod Scram Accumulators B 3.1.5 B 3.1 REACTIVITY CONTROL SYSTEMS B 3.1.5 Control Rod Scram Accumulators BASES BACKGROUND The control rod scram accumulators are part of the Control Rod Drive (CRD) System and are provided to ensure that the control rods scram under varying reactor conditions.
The control rod scram accumulators store sufficient energy to f fullyMg contre? red at any reactor vessel pressure.
f
/
The accumulator is a hydraulic cylinder with a free floating piston.
The piston separates the water used to scram the Hb,yp oI control rods from the nitrogen, which provides the required Co*pr energy.
The scram accumulators are necessary to scram the yo (3 control rods within the required insertion times of LCO 3.1.4, " Control Rod Scram Times."
APPLICABLE The analytical methods and assumptions used in evaluating SAFETY ANALYSES the control rod scram function are presented in References 1, 2, 3, and 4.
The Design Basis Accident (DBA) and transient analyses assume that all of the control rods scram at a specified insertion rate. OPERABILITY of each individual control rod scram accumulator, along with LCO 3.1.3, " Control Rod OPERABILITY," and LCO 3.1.4, ensures that the scram reactivity assumed in the DBA and transient analyses can be met. The existence of an inoperable accumulator may invalidate prior scram time measurements for the associated control rod.
The scram function of the CRD System, and.. therefore, the OPERABILITY of the accumulators, protects the MCPR Safety Limit (see Bases for LCO 3.2.2, ' MINIMUM CRITICAL POWER RATIO (MCPR)') and the 1% cladding plastic strain fuel design limit (see Bases for LCO 3.2.1, ' AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)," and LCO 3.2.3,
" LINEAR HEAT GENERATION RATE (LHGR)"), which ensure that no fuel damage will occur if these limits are not exceeded (see Bases for LCO 3.1.4).
Also, the scram function at low reactor vessel pressure (i.e., startup conditions) provides protection against violating fuel design limits during reactivity insertion accidents (see Bases for LCO 3.1.6, "Kod Pattern Control").
(continued)
A BWRf6 STS B 3.1-27 Rev.
O, 09/28/92 e
APR 28 '93 09: 3NF1 G E FUCLEAP BLDG J P.910 Control Rod Scram Accumulators B 3.1.5 BASES APPLICABLE Control rod scram accumulators satisfy Criterion 3 of the SAFETY ANALYSES NRC Policy Statement.
(continued)
LCO The OPERABILITY of the control rod scram accumulators is required to ensure that adequate scram insertion capability exists when needed over the entire range of reactor pressures. The OPERABILITY of the scram accumulators is based on maintaining adequate accumulator pressure.
t APPLICABILITY In MODES I and 2, the scram function is required for mitigation of DBAs and transients and, therefore, the scram accumulators must be OPERABLE to support the scram function.
In MODES 3 and 4, control rods are only allowed to be withdrawn under Special Operations LCO 3.10.3, "Singk "-
Control Rod Withdrawal-Hot Shutdown," and LCO 3.10.4, Control Rod Withdrawal-Cold Shutdown," which provide adequate requirements for control rod scram accumulator OPERABILITY under these conditions.
Requirements for scram accumulators in HDDE S are contained in LCO 3.9.5, " Control Rod OPERABILITY-Refueling."
ACTIONS The ACTIONS table is modified by a Note indicating that a separate Condition entry is allowed for each control rod.
This is acceptable since the Required Actions for each Condition provide appropriate compensatory action for each inoperable control rod. Complying with the Required Actions may allow for continued operation and subsequent inoperable control rods governed by subsequent Condition entry and application of associated Required Actions.
A. ] an d A. 2 't With one control rod scram accumulator inoperable and the reactor steam dome pressure t 900 psig, the control rod may be declared " slow," since the control rod will still scram at the reactor operating pressure but may not satisfy the required scram times in Table 3.1.4-1 (in the LCO).
Required Action A.1 is modified by a Note, which clarifies (continued) 1 A BWRt6 STS B 3.1-28 Rev.
O, 09/28/92
APR 28 '93 09:404f1 G E TUCLET-F BLDG.T P 7/10 Control Rod Scram Accumulators B 3.1.5 BASES ACTIONS A.1 and-k? (continued) that declaring the control rod " slow" is only applicable if l
m the associa ed control scram time w in the limits of 3g T
Table 3.1.4-cigo the las, am time test. Otherwise, M
the control rod woul leQd be considered " slow" and the
];S '"#
scra omance with an inoperable furtherdegradap hr bh (8CCumulatorCDuldresultineXCessTvescramtimes.[]
this g /A
,4 4 (6 f #, bid a event, the associated control rod is declared inoperable
\\
u " 7./-[r" (Required Action A.2) and LCO 3.13 entered.
This would
' g Of i;
result in requiring the affected control rod to be fully e
k gvP 6
Je d ! inserted and disamed, thereby sa 'sfying it intended jj h'prgc6
\\ function in accordance with ACTIONS of LCD 3.13.j V9 I
ce d ral CV
$cd6Ygl1 G
j oy f.C h6" The allowed Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is considered yt.d /%IP e
l 0
6 I3 b8 7,4 f4gy reasonable, based on the large number of control rods e
available to provide the scram functionyd the ei'ity Of-gc'yv' $ "yc u
0 r
the :ffected ccatrcl rod to sc4:ar Od y with receter-prerrure-i j
0 C1 AiSh rCCCICr E""'*" " ^
r6 f
lg j
y a
45 J# gir B.l.-B.2.1. ond B.2.2 M
Y' #
t r0g fat [pr With two or more control rod scram accumulators inoperable, 7p n
inicTbr stMirdome pressure a 900 psig, acecp: ate at, # ll I (f#
3, press.ure must be supplied to the charging watpr header.
g (6 With iifaQquate charging water pressure, a)1 of the gyf 9 g
accumulatorAcould become inoperable.pstilting in a potentially sehrr degradation of the scram perfomance.
i go$
iTherefore, within
,inutes frop. tfiscovery of charging I water header pressure 20 6
l Condition B adequate char y,psig concurrent with f
water header pressure must be
- y v " c, jg j cF" j) Dg c 'dv 50 s
restored.
The allowed f mplet Time of 20 minutes is i
N#
J considered a reasonjbi,e time to p a CRD pump into d gje h g e, d gr service to rest W the charging header essure, if o
t p
required. Jhili Completion Time also recog ' es the ability
$6 c/c la pujc of the reactor pressure alone to fully insert 11 control g
k c
e c
pe f p y Ygb f fhe control rod may be declared " slow," since the control d pV rod will iM scram using only reactor pres ay pYfp Ne " [6 not satisfy the in Table 3.1.4-ired to < >
f'ActionB.2.1ismoeifie dicating that eeciaring i
the control C only icable if the associated ga g
contrql.>cre.
1me was within the lim f Table 3.1.4-1 during the last scram time test. Otherwise, control rod
~
(continued) b8WRf6.STS B 3.1-29 Rev.
O, 09/28/92
~ _-
w e se 93 09:41ft1 G E HUCLEAR EW J P.8/10 j
Control Rod Scram Accumulators B 3.1.5 l
BASES yeds a re ACTIONS B.I. B.2.0._i d.2.2- (continued) l would already be considered " slow" and e further degradation of scram performance 4i'ttr n.dnoperabl,e j
accumulator could re.sulti n excessiv scram 17mes.
In this event, t M associ control roas declared. inoperable (Required Action
.2.
and LCO entered.
This would i
result in requiring e affected control rodsto be fully I
inserted and disame, thereby satisfying its intended 3
function in accordance with ACTIONS of LCO 3.1.3.
l
~B.1 The allowed Completion Time of I hour is considered
-prescere ts scr;; th.ge ab414+y cf si.ly reasonable, based on 16 ; cacter l
cer.tre! ret and the low probability
}
of a DBA or transient [ occurring while the affected
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accumulators are inoperaole.
NY f
+4 e caf a M h y add i& &
yo J, by -th e FMC O "' # g' L
W !T) l ca-aM+e-ea y Rith one or more control rod scram accumulators operable andMe reactor steam dome pressure < 900 psi the pressure i
supplie( to the charging water header must adequate to f
ensure th t accumulators remain charged.
ith the reactor steam-dome ressure < 900 psig, the f tion of the l
accumulators'in providing the scra orce becomes much more
{
important since\\the scram funct could become severely 1
degraded during a pressuri ion event or at low reactor pressures. Therefo e im iately upon discovery of charging water header sure < [1520] psig, concurrent with Condition C, al nt I rods associated with f
inoperable accumu ors mus verified to be fully inserted. With awn control ro with-inoperable scram l
accumulators ay fail to scram un r these low pressure conditions The associated control ds must also be i
declared noperable within I hour. Th llowed Completion f
Time o I hour is reasonable for Requirec tion C.2, con 'dering the low probability of a DBA or nsient o, urring during the time the accumulator is ino ple.
i G
l A'1 l
i The reactor mode switch must be immediately placed in the j
shutdown position if any Required Action and associated Completion Time cannot be met.
This ensures that all
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i (continued)
(
ABWRM STS B 3.1-30 Rev.
O, 09/2B/92 l
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I 4
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APR 28 '93 09 42A!1 G E HUCLEAR BLIG J P.9/30 i
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t Addiconally an automade reactor scram funcdon is provided on sensed low pressure in the CRD chargmg water header (see LCO 3.3.1.1, RPS Instrumentadon'). This andcipatory reactor tnp protects against the possibility of significant pressure degradadon (and thus reduced scram force) concurTendy in muldple control rod scram accumulators due to -
a transient in the CRD hydraulic system.
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ifR 28 '93 09:424!1 G E NUCLEAP DLDG J P.20/JO
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Control Rod Scram Accumulators B 3.1.5 BASES C
ACTIONS
,{.1 (continued) insertable control rods are inserted and that the reactor is in a condition that does not require the active function (i.e., scram) of the control rods.
This Required Action is modified by a Note stating that the Required Action is not applicable if all control rods associated with the inoperable scram accumulators are fully inserted, since the function of the control rods has been perfomed.
SURVEILLANCE SR 3.1.5.1 REQUIREMENTS SR 3.1.5.1 requires that the accumulator pressure be checked every 7 days to ensure adequate accumulator pressure exists to provide sufficient scram force. The primary indicator of accumulator OPERABILITY is the accumulator pressure. A minimum accumulator pressure is specified, below which the capability of the accumulator to perform its intended function becomes degraded and the accumulator is considered inoperable. The minimum accumulator pressure of-4520 p3ig x
is well below the expected pressure of-1750 psig to Kgb]/ when the minimum pressure is not maintained ensu
-2000 prig (Ref. 2). Declaring the accumulator inoperable gO
[gfg f *' 4) g pignificant degradation in scram times does not occur. The Q) day Frequency has been shown to be acceptable through
/f9 operating experience and takes into account other indications available in the control room.
f
" G e e ee.>/ 1/<efere s+a da rd p ro E-a yo ti-E -A'F, v e 4 1Sefen J er i9gg-frfp//ca hoo c eH nn rr 9 cc REFERENCES 1.
r<to r
S 2.
s/SAR,Sectic 4.6.1 2.2.54 %
NGM 3
,,lSAR, Sectio 5.2.2.-2.2.3}?
4.
fSAR Section 15.4.1@
ABWRffr STS B 3.1-31 Rev.
O, 09/28/92
-i 4
< -TRANSACTION REPORT >
i 34_23_13a3 m > 12:38
?
t C
RECEIVE 3
t I
f JO.
DATE T It tE DESTINATION STATION PG.
DURATION MODE RESULT 11891 4-2S 12:31 408 925 1687 10 0*05'5B" FINE.E OK
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