ML20080H025
| ML20080H025 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/10/1995 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20080H023 | List: |
| References | |
| NUDOCS 9502140360 | |
| Download: ML20080H025 (32) | |
Text
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ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PIANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-93-04, REVISION 2) 4 i
r LIST OF AFFECTED PAGES lhlil;_.1 VIII XIII 3/4 6-17 3/4 6-21 3/4 6-22 3/4 6-23 3/4 6-38 B 3/4 6-3 B 3/4 6-6 Unit 2 VIII XIII 3/4 6-17 3/4 6-21 3/4 6-22 3/4 6-23 3/4 6-39 B 3/4 6-3 i
B 3/4 6-6 j
i P
l
)
9502140360 950210 PDR ADOCK 05000327 i
P pg
i INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS
)
I SECTION PAGE 3/4.6.3 CONTAINMENT ISOLATION VALVES..............................
3/4 6-17 3/4.6.4 COMBUSTIBLE GAS CONTROL Hydrogen Analyzers....................../!...............
3/4 6-24 Electric Hydrogen Recombiners.............................
3/4 6-25 3/4.6.5 ICE CONDENSER 4
Ice Bed...................................................
3/4 6-26 Ice Bed Temperature Monitoring System.....................
3/4 6-28 Ice Condenser Doors.......................................
3/4 6-29 Inlet Door Position Monitoring System.....................
3/4 6-31 Divider Barrier Personnel Access Doors and Equipment Hatches.......................................
3/4 6-32 Containment Air Return Fans...............................
3/4 6-33 Floor Drains..............................................
3/4 6 Refueling Canal Drains....................................
3/4 6-35 f
Divider Barrie ea1.............'.........................
3/4 6-36 wED 3/4.6.6 VACUUM RELIEF.TL'!LL.....................................
3/4 6-38 3/4.7 PLANT SYSTEMS I
3/4.7.1 TURBINE CYCLE Safety Va1ves.............................................
3/4 7-1 l
t A ux i l i a ry Fe edwa t e r Sy s t em.................................
3/4 7-5
~
f Condensate Storage Tank..............:....................
3/4 7-7 Activity..................................................
3/4 7-8 Main Steam Line Isolation Va1ves..........................
3/4 7-10 l
3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION...........
3/4 7-11 3/4.7.3 COMPONENT COOLING WATER SYSTEM............................
3/4 7d12 3/4.7.4 ESSENTIAL RAW COOLING WATER SYSTEM i
Essential Raw Cooling Water System..................
3/4 7-13 R124 e SEQUOYAH - UNIT 1 VIII gmgnd{entg. II6
. o INDEX
}
BASES SECTION PAGE 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE.............................
B 3/4 4-4 1
3/4.4.7 CHEMISTRY..................................................
B 3/4 4-5 l
3/4.4.8 SPECIFIC ACTIVITY..........................................
B 3/4 4-5 3/4.4.9 PRESSURE / TEMPERATURE LIMITS................................
B 3/4 4-6 3/4.4.10 STRUCTURAL INTEGRITY......................................
B 3/4 4-14 3/4.4.11 REACTOR COO LANT SYSTEM HEAD VENTS.........................
B 3/4 4-14 R161:
3/4.4.12 OVERPRESSURE PROTECTION SYSTEMS...........................
B 3/4 4-14 3
3/4.5 EMERGENCY CORE COOLING SYSTEMS 1
3/4.5.1 ACCUMULATORS...............................................
B 3/4 5-1 t
3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS................................
B 3/4 5-1 h3/4.5.4 BORON INJECTION SY5 TEM.....................................
B 3/4 5-2 3/4.5.5 REFUELING WATER STORAGE TANK...............................
B 3/4 5-2 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT........................................
B !!< c '
3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS.......................
B3 3
3/4.6.3 CONTAINMENT ISOLATION VALVES...............................
B 3/4 6-3 3/4.6.4 COMBUSTIBLE GAS CONTR0L....................................
B 3/4 6-3 3/4.6.5 ICE CONDENSER B 3/4 6-4 i
3/4.6.6 VACUUM RELIEF.nm.co.......................................
B 3/4 6-6 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE..............................................
B 3/4 7-1 3/4.7.2 STEAM GENERATOR PRESSURE /TEMERATURE LIMITATION.............
B 3/4 7-3 3/4.7.3 COMPONENT COOLING WATER SYSTEM.............................
B 3/4 7-3 1
SEQUOYAH - UNIT 1 XIII Amendment No.157 March 30, 1992
4 1
c '
I CONTAINMENT SYSTEMS i
3 O
3/4.6.3 CONTAINMENT-ISOLATION VALVES l
LIMITING CONDITION FOR OPERATION I
3.6.3 The containment isolation valves specified in Table 3.6-2 shall be R16 OPERABLE with isolation times as shown in Table 3.6-2.
APPLICABILITY: MODES 1, 2, 3 and 4.
ACTION:
Sedsens A,0, 0 ""
'f
'*"3 O'
Withoneormoreoftheisolationvalve(s)specifiedin! Table 3.6-2 inoperable, maintain at least one isolation valve OPERABLE in each affected penetration that is open and either:
p'.
Restore the inoperable valve (s) to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or t
/.
Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one deactivated automatic valve secured in the isolation position, or g.
Isolate eai:h affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one closed manual valve or blind flange; or g.
Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD l
SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
SURVEILLANCE REQUIREMENTS 4.6.3.1 The isolation valves specified in Table 3.6-2 shall be demonstrated R16,
OPERABLE prior to returning the valve to service after maintenance, repair or replacement work is performed on the valve or its associated actuator, control or power, circuit by performance of a cycling test and verification of isolation time.
cod.:nma,;t scuam <al:6 aselsk valg) pdkJ s.
uikk one. oc enora.
aa sad..as 0.1 acoy k o.3 & T Ue. 3.6-z im arJIe., &
vald) mus+ be. reh<nd +, cPEkA&E SUus A.h 72 kre, i
bt ln b lea.s[ hot 57%3D8 Y' 40.$;,, & nexi 4 koors l
o r*
a r,).
[O4.0 SHOT *0ou.)A.)
U*IkoA Y
- A} O
- " f5 '
sn j
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SEQUOYAH - UNIT 1 3/4 6-17 Amendment No. 12 March 25, 1982
.m-t TABLE 3.6-2 (Continued) mE CONTAINMENT ISOLATION VALVES C
S VALVE NUMBER FUNCTION MAXIMUM ISOLATION TIME (Seconds)
I A.
PHASE "A" ISOLATION (Cont.)
e 61.
FCV-77-19 RCDT and PRT to V H 10*
3 62.
FCV-77-20 N to RCDT 10*
2 63 FCV-77-127 Floor Sump Pump Disch 10*
64.
FCV-77-128 Floor Sump Pump Disch 10*
65.
FCV-81-12 Primary Water Makeup 10*,
B.
PHASE "B" ISOLATION
'R144 l.
1.
FCV-32-80 Control Air Supply 10 2.
FCV-32-102 Control Air Supply 10 3.
FCV-32-Il0 Control Air Supply 10 4.
FCV-67-83 ERCW - LWR Cmpt Clrs 60*
5.
FCV-67-87 ERCW - LWR Cmpt Clrs 60*
R 6.
FCV-67-8 ERCW - LWR Cmpt Clrs 60*
7.
FCV-67-8 ERCW - LWR Cmpt Clrs 70*
T 8.
FCV-67-9 ERCW - LWR Cmpt Clrs 70*
y 9.
FCV-67-91 ERCW - LWR Cmpt Clrs 60*
10.
FCV-67-95 ERCW - LWR Cmpt Clrs 60*
11.
FCV-67-96 ERCW - LWR Cmpt Clrs 60*
12.
' FCV-67-99 ERCW - LWR Cmpt Clrs 60*
13.
FCV-67-103 ERCW - LWR Cmpt Clrs 60*
14.
FCV-67-10 ERCW - LWR Cmpt Clrs 60*
15.
FCV-67-10 ERCW
. LWR Cmpt Clrs 70*
gy 16.
FCV-67-10 ERCW - LWR Cmpt Cirs 70*
b g 17.
FCV-67-107 M g-18.
FCV-67-111 ~
g 19.
FCV-67-112 ERCW - LWR Cmpt Cirs 60*
20.
FCV-67-130 ERCW - Up Cmpt Cirs 60*
z 21.
FCV-67-131 ERCW - Up Cmpt Cirs 60* 22.
FCV-67-133 ERCW - Up Cmpt Clrs 3
g 23.
FCV-67-134 ERCW - Up Cmpt Clrs
. 60*
- 60*
24.
FCV-67-138.
ERCW - Up Cmpt Cirs 60*
.c?
M O
w m
.mw -
..-- 2 e-
=
w-m__-u.c-,-e
.rw.w w-
..z-,-+v
,..m.-e.., -. -
w
,w.mw
.. ~ -
e.,.w
...n-e w
,,y.,
-y
TABLE 3.6-2 (Continued) 3-[..
5
.g-CONTAINMENT ISOLATION VALVES
\\
l '
' VALVE NUMBER FUNCTION MAXIMUM ISOLATION TIME (Seconds) h B.
PHASE "B" ISOLATION (Cont.) -
25.
FCV-67-139 ERCW - Up Capt Clrs 60*'
26.
FCV-67-141 ERCW - Up Capt'Clrs 60*
27.
FCV-67-142-ERCW - Up Capt Clrs 60*
R81 i
28.
FCV-67-295 ERCW - Up Capt Clrs 60*
29.
FCV-67-296 ERCW - Up Capt Clrs 60*
30.
FCV-67-297 ERCW - Up Capt Clrs 60*
31.
FCV-67-298 ERCW - Up Capt Clrs-60*
32.
FCV-70-87 RCP Thermal Barrier Ret
.60 33.
FCV-70-89 CCS from RCP Oil Coolers,
60 m
N 34.
FCV-70-90 RCP Thermal Barrier Ret 60
,[
35.
FCV-70-92 CCS from RCP Oil Coolers 60 36.
FCV-70-134-To RCP Thermal Barriers 60
<,O 37.
FCV-70-140 n CCS to RCP Oil Coolers 60 38.
FCV-70-141t'8/
CCS to RCP Oil Coolers 65 R86 C.
PHASE "A" CONTAINMENT VENT ISOLATION 1.
FCV-30-7 Upper Compt Purge Air Supply 4*
i 2.
FCV-30-8 Upper Compt Purge Air Supply 4*
3.
FCV-30-9 Upper Compt Purge' Air Supply 4*
-,p 4.
FCV-30-10 Upper compt Purge Air Supply 4*
io 5.
FCV-30-14 Lower Compt Purge Air Supply 4*
- j 6.
FCV-30-15 Lower Compt Purge Air Supply 4*:
R41 i
F g-7.
FCV-30-16 Lower Compt Purge Air Supply 4*
8.
FCV-30-17 Lower Compt Purge Air Supply 4*
9.
FCV-30-19
' Inst Room Purge Air Supply 4*
10.
FCV-30-20 Inst Room Purge Air Supply 4*
11.
FCV-30-37.
Lower Compt Pressure Relief 4*
$g-12.
FCV-30-40 Lower Compt Pressure Relief 4*
.- \\..
^
- (.. ).
4 S.
- ~
m
.. ; N[n.
-V TABLE ~ 3,6'-2 ContinuedF Q
+
.m
' CONTAINMENT ISOLATION VALVES ~
^
Z
~
8:
VALVE NUMBER.
FUNCTION MAXIMUM' ISOLATION TIME fSeconds) 5 C.
PHASE "A" CONTAINMENT VENT ISOLATION-(Cont.)-
's i
13.
FCV-30-50 Upper Compt Purge Air Exh 4*
Q 14.
FCV-30. Upper Compt Purge Air Exh 4*
.R74 15.
FCV-30-52 Upper Compt Purge Air Exh 4*
16.
FCV-30-53 Upper Compt Purge Air Exh 4*
17.
FCV-30-56 Lower Compt Purge Air Exh 4*'
18.
FCV-30-57 Lower Compt Purge Air Exh 4*
~19.
FCV-30-58.
Inst Room Purge Air Exh 4*
20.
FCV-30-59 Inst Room Purge Air Exh 4*
21.
FCV-90-107 Cntmt Bldg LWR Compt Air Mon 5*
i 22.
FCV-90-108 Cntmt Bldg LWR Compt Air Mon 5*
i 23.
FCV-90-109 Cntmt Bldg LWR Compt Air Mon 5*
l 24.
FCV-90-Il0 Cntmt Bldg LWR Compt Air Mon 5*
w 25.
FCV-90-Ill Cntmt Bldg LWR Compt Air Mon 5*
3 26.
FCV-90-113 Cntmt Bldg UPR Compt Air Mon 5*
FCV 90-Il4 Cntmt Bldg UPR Compt Air Mon 5*
y 27.
m 28.
FCV-90-Il5 Cntmt Bldg UPR Compt Air Mon 5*
l 29.
FCV-90-116 Cntmt' Bldg UPR Compt Air Mon 5*
30.
FCV-90-Il7 Cntmt Bldg UPR Compt Air Mon 5*
D.
OTHER g
e a R ;;
1.
FCV-30 Vacuum Relief Isolation Valve 25 2g 2.
FCV-30-47 Vacuum Relief Isolation Valve
~25' E.x 3.
FCV-30-48 Vacuum Relief Isolation Valve 25 R105 l
z ;;
7 FCV-62-90
' Normal Charaing Isolation Valve _
12
.r.
so-5,t-v.a.m R< t:e s> <e-y o
6.
1 Jo-5'72.
Wc..- Rd Al <d.
p G-10 - 573 v.c.g Pe l_
udet.
g.
w
- Provisions.of LCO 3.0.4 are' not applicable if valve is secured in its isolated pos on with power removed R180'
- E and leakage limits of Specification.4.6.1.1.c-are satisfied.
For purge valves, leakage limits under l
Surveillance. Requirement 4.6.1.9.3 must also be satisfied.
~
- Provisions of LCO 3.0.4 are not, applicable if valve is secured in-its isolated position with power removed R41 y
and either FCV-62-73 or FCV-62-74 is maintained operable.
- ru.
..1...
4.-' --..
.a ss.
,__i_.2._
or 6k.
,,,,,4,+.,a
_,44cc, **--
R86' g
rel<
\\ b r5YY t hf$
hen. 5 e. Y NYm iseIb
'ws
- 'S ne$
N f onNt Yo e
s a n ~ q s.s kers.IE k,, ~1xs.
s l
0%
no
.s:
+
t CONTAINMENT SYSTEMS LIMEG 3/4.6.6 VACUUM RELIEF VALWF LIMITING CONDITION FOR OPERATION
- . shall be OPERABLEf-wih-
- 3. 6. 6h.ua t4on-se t-point-o f4es s-ther:
The pr ary containment vacuum relief 2n ec Or q=1 t: 0.1 PS W APPLICABILITY: MODES 1, 2, 3 and 4.
ACTION:
i fina With one primary containment vacuum relief inoperable, restore the to OPERABLE status within hours or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
SURVEILLANCE REQUIREMENTS 4.6.6.1 No additional Surveillance Requirements other than those required by
}
Specification 4.0.5.
Refee +,
LCo
- 3. 4. 3
- f o n e.
e, k,%,$ vuuu, ce more coda.nment vacuum reI.'e.-f vabec are.
rel,af sk.\\0.6n or
,,; e4ac. & p4ca, 3 a c.,L.. -cd a's.I&:.n Lc%.
m SEQUOYAH - UNIT 1 3/4 6-38
- _. - ~
3 3
CONTAINMENT' SYSTEMS l
(
BASES t
3/4.6.1.8 EMERGENCY GAS TREATMENT SYSTEM (EGTS) l TheOPERABILITYoftheEGTScleanupsubsystemensuresthatduringL6CA
{
conditions, containment vessel leakage into the annulus will be filtered j
through the HEPA' filters and charcoal adsorber trains prior to discharge to j 7P j
the atmosphere.
This requirement is necessary to meet the assumptions used in i
the accident analyses and limit the site boundary radiation doses to within the limits of 10 CFR 100 during LOCA conditions.
Cumulative operation of the i
system with the heaters on for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31 day period is sufficient to l
reduce the buildup of moisture on the absorbers and HEPA filters.
ANSI N510-1975 l
3113 will be used as a procedural guide.for surveillance testing.
~
4 3/4 6.1.9 CONTAINMENT VENTILATION SYSTEM i
Use of the containment purge' lines is restricted to only one pair (one i
supply line and one exhaust line) of purge system lines at a time to ensure that the site boundary dose guidelines of 10 CFR Part 100 would not be exceeded in the event of'a loss of coolant accident during purging operations. The analysis of this accident assumed purging through the largest pair of lines (a 24 inch inlet line and a 24 inch outlet line), a pre-existing iodine spike in the reactor coolant and four second valve closure times.
}
3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS l
3/4.6.2.1 CONTAINMENT SPRAY SUBSYSTEMS 3133 l
The OPERABILITY of the containment spray subsystems ensures that contain-I ment depressurization and cooling capability will be available in the event of a LOCA.
The pressure reduction and resbitant lower containment leakage rate are consistent with the assumptions used in the accident analyses.
3/4.6.2.2 CONTAINMENT COOLING FANS l
The OPERABILITY of the lower containment vent coolers ensures that'ade-R71 quate bett removal capacity is available to provide long-term cooling following a non-LOCA. event.
Postaccident use of these coolers ensures containment tem-peratures remain within environmental qualification limits for all. safety-l related equipment required to remain functional.
l 3/a.6.3 CONTAINMENT ISOLATION VALVES l
The valves identified in Table 3.5-2 are containment isolation valves as l
defined per 10 CFR 50.
The operability of these containment isolation valves ensures that the containment atmosphere will be isolated from the outside l
environment in the event of a release of radioactive material to the contain- ~
R153 ment atmosphere or pressurization of the containment.
Containment isolation within the time limits specified ensures that the release of radioactive mate-rial to the environment will be consistent with the assumptions used in the analyses for a loss of coolant accident.
l Additional valves have been identified as barrier valves, which in addition i
to the containment isolation vs.lves discussed above, are a part of the accident monitoring instrumentation in Technical Specification 3/4.3.3.7 and I
are designated as Category 1 in accordance with Regulatory Guide 1.97,
(
Revision 2, " Instrumentation for Light-Water-Cooleo Nuclear Power Plants to l
Assess Plant Conditions During and Following an 4ccioent," December 1980.
i SEQUOYAH - UNIT 1 B 3/4 6-3 Amendment No. 67, 114, 150 I9
-- d 5-b A July 9, 1992 j
^
^
n,
. ~.
J 4
t t
INSERT A Note that due to competing requirements and dual functions associated with the containment vacuum relief isolation valves (FCV-30-46,
-47, and -48), the air supply and solenoid i
arrangement is designed such that upon the unavailability of Train A essential control air, the containment vacuum relief isolation valves are incapable of automatic closure and are i
therefore considered inoperable for the containment isolation function without operator action.
The containment vacuum relief valves (30-571, -572, and -573) are qualified to perform a containment isolation function.
These valves are not powered from any electrical source and no spurious signal or operator action could initiate opening.
The valves are spring loaded, swing disk (check) valves with an elastomer seat.
The valves are normally closed and are equipped with limit switches that provide fully open and fully closed indication in i
j the main control room (MCR). Based upon the above information, a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed action time is appropriate while actions are taken to return the containment vacuum relief isolation valves to service.
e i
P l
i l
f
CONTAINMENT SYSTEMS BASES 3/4.6.5.7 and 3/4.6.5.8 FLOOR AND REFUELING CANAL DRAINS The OPERABILITY of the ice condenser floor and refueling canal drains ensures that following a LOCA, the water from the melted ice and containment spray system has access for drainage back to the containment lower compartment and subsequently to the sump.
This condition ensures the availability of the water for long term cooling of the reactor during the post accident phase.
3/4.6.5.9 OIVIDER BARRIER SEAL The requirement for the divider barrier seal to be OPERABLE ensures that a minimum bypass steam flow will occur from the lower to the upper containment compartments during a LOCA.
This condition ensures a diversion of steam through the ice condens rl a s that is consistent with the LOCA analyses.
3/4.6.6 VACUUM RELIEF"Y b bc OPERABILITY of imary containment to atmosphere vacuum relief va4ves ensures that the containment internal pressure does not become more negative than 0.1 psid.
This condition is necessary to prevent exceeding the containment design limit for internal vacuum of 0.5 psid.
A v a cu u,-, re I.c f I.'n e-con s.s4s efa seICaduak.o
)
ocuum re he( value,
fnev~a.h.'eall ogeraha) sgolah,on aIJe,assoinehe a
f f;"Q.,
a n k in Nrum enYa h. 'en conhroI s.
et n SEQUOYAH - UNIT 1 B 3/4 6-6 Revised 08/18/87
J INDEX
~-
LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.6.3 CONTAI,NMENT ISOLATION VALVES..............................
3/4 6-17 I
~
3/4.6.4 COMBUSTISLE GAS CONTROL Hydrogen Monitors.........................................
3/4 6-24 H
Electric Hydrogen Recombiners.............................
3/4 6-25
~
r u:
Hydrogen Control Interim Distributed Ignition System.....
3/4 6-26 2.v.
3/4.6.5 ICE CONDENSER Ice Bed...................................................
3/4 6-27 Ice Brd Temperature Monitoring System.....................
3/4 6-29 a.
~ i Ice Condenser Doors.......................................
3/4 6-30 Inlet Door Position Monitoring System.....................
3/4 6 Divider Barrier Personnel Access Doors and
~,.,
Equipment Hatches.......................................
3/4 6-33 Containment Air Return Fans...............................
3/4 6-34 a,.
Floor Drains..............................................
3/4 6-35 M.4h.ii Refueling Canal Drains....................................
3/4 6-36 D i v i de r Ba rri e J a1.....................................
3/4 6-37 LW D 3/4.6.6 VACUUM RELIEF s......................................
3/4 6-39
'[~
T 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE Safety Va1ves.............................................
3/4 7-1 q:..
i Auxiliary Feedwater System................................
3/4 7-5 Condensate Storage Tank................'...................
3/4 7-7 Activity...............[..................................
3/4 7-8 l
Mai n Steam Li ne Isol ati on Va1 ves..........................
3/4 7-10 3/4.7.2 STEAM GENERATOR PRESE lE/ TEMPERATURE LIMITATION...........
3/4 7-11 3/4.7.3 COMPONENT COOLING WATER SYSTEM............................
3/4 7-12 SEQUOYAH - UNIT 2 VIII
INDEX i
)
BASES i
l SECTION I
PAGE 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE.............................
B 3/4 4-4 3/4.4.7 CHEMISTRY.........................
B 3/4 4-5 3/4.4.8 SPECIFIC ACTIVITY..........................................
B 3/4 4-5 3/4.4.9 PRESSURE / TEMPERATURE LIMITS................................
B 3/4 4-6 3/4.4.10 STRUCTURAL INTEGRITY......................................
B 3/4 4-14 3/4.4.11 REACTOR COOLANT SYSTEM HEAD VENTS.........................
B 3/4 4-15 3/4.4.12 OVERPRESSURE PROTECTION SYSTEMS...........................
B 3/4 4-15 r
3/4.5 EMERGENCY CORE COOLING SYSTEMS d
3/4.5.1 ACCUMULATORS...............................................
B 3/4 5-1 I
3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS................................
B 3/4 5-1 3/4.5.4 BORON INJECTION SYSTEM.....................................
B 3/4 5-2 l
3/4.5.5 REFUELING WATER STORAGE TANK...............................
B 3/4 5-2 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT........................................
B 3/4 6-1 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS.......................
B 3/4 6-3 3/4.6.3 CONTAINMENT ISOLATION VALVES...............................
B 3/4 6-3 3/4.6.4 COMBUSTIBLE GAS CONTR0L....................................
B 3/4 6-3 3/4.6.5 ICE CONDENSER.
B 3/4 6-4 3/4.6.6 VACUUM RELIEF
.-,.m5.......................................
B 3/4 6-6 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE..............................................
B 3/4 7-1 i
3/4.7.2 STEAM GENERATOR PRESSURE /TEMERATURE LIMITATION.............
B 3/4 7-3 3/4.7.3 COMPONENT COOLING WATER SYSTEM.............................
B 3/4 7-3 SEQUOYAH - UNIT 2 XIII Amendment No.147 March 30, 1992
. CONTAINMENT SYSTEMS.
i p, O CONTAINMENT ISOLATION VALVES 3/4.6.3 LIMITING CONDITION FOR OPERATION The containment isolation valves specified in Table 3.6-2 shall be 3.6.3 OPERABLE with isolation times as shown in Table 3.6-2.
APPLICABILITY: MODES 1, 2, 3 and 4.
'7 Secfdas A, k O 4ad O'4 ACTION:
~
hWithoneormoreoftheisolationvalve(s)specifiedinTable3.6-2 inop maintain at least one isolation valve OPERABLE in each affected penetration that is open and either:
Restore the inoperable valve (s) to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, p.
5 or Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at lea'st one deactivated automatic valve secured in the isolation position, F.
or I
Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least f.
one closed manual valve or blind flange, or cyg Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COL at SHUTOOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
SURVEILLANCE REQUIREMENTS The isolation valves specified in Table 3.6-2 shall be demonstrated OPERABLE prior to returning the valve to service af ter maintenance, repair or 4.6.3.1 replacement work is performed on the valve or its a 9
time.
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W.% one. oe thravyh D.3 eh Tal,f,_ 3,g.z,,,,,gj(,
s'n G ect.*e,n s D.L s+ dss w.E.a, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />;
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SEQUOYAH - UNIT 2 3/4 6-17
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(
h TABLE 3.6-2 (Continued) 1Nj CONTAINMENT ISOLATION VALVES E
VALVE NUMBER FUNCTION MAXIMUM ISOLATION TIME (Seconds)
A.
PHASE "A" ISOLATION (Cont.)
R62
- 62. FCV-77-20 N to RCDT 10*
2
- 63. FCV-77-127 Floor Sump Pump Disch 10*
- 64. FCV-77-128 Floor Sump Pump Disch 10*
- 65. FCV-81-12 Primary Water Makeup 10*
R131 B.
PHASE "8" ISOLATION 1.
FCV-32-81 Control Air Supply 10 2.
FCV-32-103 Control Air Supply 10 R29 3.
FCV-32-111 Control Air Supply 10 4.
FCV-67-83 ERCW - LWR Capt Cirs 60*
R 5.
FCV-67-87 ERCW - LWR Capt Clrs 60*
6.
FCV-67-8 ERCW - LWR Cmpt Clrs 60*
T 7.
FCV-67-8 ERCW - LWR Capt Clrs 70*
R73 y
8.
FCV-67-9 ERCW - LWR Capt Cirs 70*
9.
FCV-67-91 ERCW - LWR Capt Cirs 60*
g R29
m E
2
5
R73
2 P
Dy
R29 3*
- 20. FCV-67-130 ERCW - Up Cmpt Clrs 60*
~I DO
- 21. FCV-67-131 ERCW - Up Cnpt Clrs 60*
- 22. FCV-67-133 ERCW - Up Cmpt Cirs 60*
m D,e
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TABLE 3.6-2 (Continued)
,m CONTAINMENT ISOLATION VALVES E
VALVE NUMBER FUNCTION MAXIMUM ISOLATION TIME (Seconds)
B.
PHASE "B" ISOLATION (Cont.)
- 23. FCV-67-134 ERCW - Up Capt Clrs 60*
- 24. FCV-67-138 ERCW - Up Capt Cirs 60*
- 25. FCV-67-139 ERCW - Up Capt C1rs 60*
- 26. FCV-67-141 ERCW - Up Capt Clrs 60*
- 27. FCV-67-142 ERCW - Up Capt Clrs 60*
- 28. FCV-67-295 ERCW - Up Capt Cirs 604 R29
- 29. FCV-67-296 ERCW - Up Capt Clrs 60*
- 30. FCV-67-297 ERCW - Up Capt Clrs 60*
- 31. FCV-67-298 ERCW - Up Capt Clrs 60*
- 32. FCV-70-87..
RCP Thermal Barrier Ret 60
' R
- 34. FCV-70-90 RCP Thermal Barrier Ret 60 T
- 36. FCV-70-134 To RCP Thermal Barriers 60 l
g73 C.
PHASE "A" CONTAINMENT VENT ISOLATION 1.
FCV-30-7 Upper Coupt Purge Air Supply 4*
2.
FCV-30-8
. Upper Compt Purge Air Supply 4*
3.
FCV-30-9 Upper Compt Purge Air Supply 4*
4.
FCV-30-10 Upper Compt Purge Air Supply 4*
R29 5.
FCV-30-14 Lower Compt Purge Air Supply 4*
m T
0 6.
FCV-30-15 Lower Compt Purge Air Supply 4*
I 2
7.
FCV-30-16 Lower Compt Purge Air Supply 4*
t
?
8.
FCV-30-17 Lower Compt Purge Air Supply 4*,
j 4
9.
FCV-30-19 Inst Room Purge Air Supply 4*
- 10. FCV-30-20 Inst Room Purge Air Supply 4*
f
- 11. FCV-30-37 Lower Compt' Pressure Relief 4*
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- 12. FCV-30-40 Lower Compt Pressure Relief 4*
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TABLE 3.s (Continued)
.y CONTAIMMENT ISOLATION VALVES VALVE NUMBER FUNCTION MAXIMUM ISOLATION TIME (Seconds)
C.
PHASE "A" CONTAINMENT VENT ISOLATION (Cont.)
C 3
13.
FCV-30-50 Upper Compt Purge Air Exh 4*
I 14.
FCV-30-51 Upper Compt Purge Air Exh 4*
R62 15.
FCV-30-52 Upper Compt Purge Air Exh 4*-
i 16.
FCV-30-53 Upper Compt Purge Air Exh 4*
17.
FCV-30-56 Lower Compt-Purge Air Exh 4*
18.
FCV-30-57 Lower Compt Purge Air Exh 4*
19.
FCV-30-58
-Inst Room Purge Air Exh 4*
20.
FCV-30-59 Inst Room Purge Air Exh 4*.
21.
FCV-90-107 Cntat' Bldg-LWR Compt Air Mon 5*
22.
FCV-90-108 Cntet Bldg LWR Compt Air Mon 5*
23.
FCV-90-109 Cntet Bldg LWR Compt Air Mon 5*
w 24.
FCV-90-Il0
.Cntat Bldg LWR Compt Air Mon 5*
1 25.
FCV-90-Ill
'Cntat Bldg LWR Compt Air Mon 5*
m 26.
FCV-90-ll3 Cntet Bldg UPR Compt Air Mon 5*
A 27.
FCV-90-Il4 Cntet Bldg UPR Compt Air Mon 5*
'28.
FCV-90-Il5 Cntat Bldg UPR Compt Air Mon 5*
29.
FCV-90-Il6 Cntet Bldg UPR Compt Air Mon 5*
30.
FCV-90-Il7 Cntmt Bldg UPR Compt Air Mon 5*
'rj D.
OTHER
- s is 1.
FCV-30-46 Vacuum Relief Isolation Valve 25 2.
FCV-30-47 Vacuum Relief Isolation Valve 25 5E FCV-30 Vacuum Relief Isolation Valve
-25 R90 FCV-62 Normal Charging Isolation Valve 12
- ~
- -So-571
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- Provisions of LCO 3.0.4 are not applicable 1f valve ls secured in its isolated position with power removed I
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'e and leakage limits of Specification 4.6.1.1.c are satisfied.
For purge valves, leakage limits under surveillance Requirement 4.6.1.9.3 must also be satisfied.
b
- Provisions of LCO 3.0.4 are not applicable if valve 'is' secured in its isolated position with power removed and either FCV-62-73 or FCV-62-74 is maintained operable.
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CONTAINMENT SYSTEMS LwES
-3/4.6.6 VACUUM RELIEF /AL'/E5*
,l LIMITING COND)T10N FOR OPERATION T1 re4.
3.6.6 The primary containment vacuum relief "act shall be OPERABLE " ---
actuction ::t peint of le:: than er equ:1 10 0.1 p;ii APPLICABILITY:
MODES 1, 2, 3 and 4.
ACTION:
I.~n c.
., ith one primary containment vacuum relief inoperable, restore the.
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line.
valve to OPERABLE status within hours or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and ir COLD TDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
'72.
SURVEILLANCE REQUIREMENTS i
i 4.6.6 No additional Surveillance Requirements other than those required,by
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i 5pecification 4.0.5.
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- 3. 4. 3
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conYa.h nenY dacuum redd valves _ arc.
re.l.'ef iseldie n or don $se'n menk o'Go$r$n'en fon ch,'ca,
Inca.fahlt OS Per $ semen Ct' SEQUDYAH - UNIT 2 3/4 6-39
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t CONTAINMENT SYSTEMS BASES
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3/4.6.1.8 EMERGENCY GAS TREATMENT SYSTEM (EGTS)
The OPERABILITY of the EGTS cleanup subsystem ensures that during LO'CA conditions, containment vessel leakage into the annulus will be filtered i
through the HEPA filters and charcoal adsorber trains prior to discharge to l
the atmosphere.
This requirement is necessary to meet the assumptions used in i
the accident analyses and limit the site boundary radiation doses to within the limits of 10 CFR 100 during LOCA conditions.
Cumulative operation of the system with the heaters on for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31 day period is sufficient to i
reduce the buildup of moisture on the absorbers and'HEPA filters. ANSI N510-1975 will be used as a procedural guide for surveillance testing.
3/4.6.1.9 CONTAINMENT VENTILATION SYSTEM Use of the containment purge lines is restricted to only one pair (one supply line and one exhaust line) of purge system lines at a time to ensure that the site boundary dose guidelines of 10 CFR Part 100 would not be exceeded in the event of a loss of coolant accident during purging operations. The analysis of this accident assumed purging through the largest pair of lines (a 24 inch inlet line and a 24 inch outlet line), a pre existing iodine spike in the reactor coolant and four second valve closure times.
3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS 3/4.6.2.1 CONTAINMENT SPRAY SUBSYSTEMS 3:40
[iW.
The OPERABILITY of the containinent spray subsystems ensures that contain-
[
ment depressurization and cooling capability will be available in the event of a LOCA.
The pressure reduction and resultant lower containment leakage rate i
are consistent with the assumptions used in the accident analyses.
l 3/4.6.2.2 CONTAINMENT COOLING FANS l
The OPERABILITY of the lower containment vent coolers ensures that ade-quate heat removal capacity is available to provide long-term cooling following m
^^
a non-LOCA event.
Postaccident use of these coolers ensures containment tem-peratures remain within environmental qualification limits for all safety-related equipment required to remain functional.
i 3/4.6.3 CCNTAINMENT ISOLATION VALVES The valves identified in Table 3.6-2 are containment isniation valves as i
defined per 10 CFR 50.
The operability of these containment isolation valves l
ensures that the containment atmosphere will be isolated from the outside environment in the-event of a release of radioactive material to the contain-R149 i
ment atmosphere or pressurization of the containment.
Containment isolation within the time' limits specified ensures that the release of radioactive mate-i rial to the environment will be consistent with the assumptions used in the analyses for a loss of coolant accident.
Additional valves have been identified as barrier valves, which in addition to the containment isolation valves discussed above, are a part of the accident monitoring instrumentation in Technical Specification 3/a.3.3.7 and are designated as Category 1 in accordance with Regulatory Guide 1.97, Revision 2, " Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1980.
SEQUOYAH - UNIT 2 B 3/4 6-3 Amendment No. 59, 140 149 7g July 9, 1992
.~ _
INSERT A l
Note that due to competing requirements and dual functions associated with the containment vacuum' relief isolation valves (FCV-30-46,
-47, and -48), the air supply and solenoid l
arrangement'is designed such that upon the-unavailability of i
Train A essential control air, the containment. vacuum relief isolation valves are incapable of automatic closure and are l
therefore considered inoperable for the containment isolation function without operator action.
The containment vacuum relief valves (30-571, -572, and -573) are i
qualified to perform a containment' isolation function. _These valves are not powered from any electrical source and no spurious signal or operator action could initiate opening.
The valves are spring. loaded, swing disk (check) valves with an elastomer seat.
The valves are normally closed and are equipped with limit r
switches that provide fully open and fully closed indication in the main control room (MCR). Based upon the above information, a l
72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed action time is appropriate while actions are j
taken to return the containment vacuum relief isolation valves to l
service.
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CONTAINMENT SYSTEMS BASES l
i 3/4.6.5.7 and 3/4.6.5.8 FLOOR AND REFUELING CANAL DRAINS The OPERABILITY of the ice condenser floor and refueling canal drains ensures that following a LOCA, the water from the melted ice and contair. ment spray system has access for drainage back to the containment lower compartment and subsequently to the sump.
This condition ensures the availability of the water for long term cooling of the reactor during the post accident phase.
3/4.6.5.9 DIVIDER BARRIER SEAL The requirement for the divider barrier seal to be OPERABLE ensures that a minimum bypass steam flow will occur from the lower to the upper containment compartments during a LOCA.
This condition ensures a diversion of steam through the ice condenser bays that is consistent with the LOCA analyses.
bMC 3/4.6.6 VACUUM RELIEF VALVES The OPERABILITY of rimary containment to atmosphere vacuum relie valves ensures that the containment internal pressure does not become more negative than 0.1 psid.
This condition is necessary to prevent exceeding
)
the containment design limit for internal vacuum of 0.5 psid.
A vacuum re l,e f^ I:nc con s:s+s of a se lf-ac +u eb.n 3 vacuum f ne u m A ca 0operabek Esdshn va lve, a ss> coded relle[ valve,
o-
- f. %n 3, and o'n slr menhbeen and con $ce I s,
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SEQUOYAH - UNIT 2 B 3/4 6-6 Revised 08/18/87 BR December 7, 1990p,r.- ^ r; <,9 q
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.l ENCLOSURE 2 PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PIANT UNITS 1 AND 2 l
DOCKET NOS. 50-327 AND 50-328 (TVA-SQN-TS-93-04, REVISION 2) i DESCRIPTION AND JUSTIFICATION FOR CONTAINMENT VACUUM RELIEF LINES r
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1 Description of Change m
TVA proposes to revise SQN Technical Specifications (TSs) 3/4.6.3, "Contninment Isolation Valves " and 3/4.6.6 " Vacuum Relief Valves," and their associated bases.
I The first proposed change adds a new action statement to SQN TS 3/4.6.3 that reads:
l "b.
With one or more vacuum relief isolation valve (s) specified in l
Sections D.1 through D.3 in Table 3.6-2 inoperable, the valve (s) must be
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returned to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or be in at least HOT SIANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."
Included with the new action statement is a revision that designates the current action statement as Action Statement (a) and inserts the phrase,
" Sections A, B, C, and D.4 through D.7 of," as it applies to Table 3.6-2.-
The second proposed change revises TS 3/4.6.6 to incorporate the following:
Revise Limiting Condition for Operation (LCO) 3.6.6 to state:
"Three a.
primary containment vacuum relief lines shall be OPERABLE."
b.
Add a footnote to LCO 3.6.6 that states:
" Refer to LCO 3.6.3 if one or more containment vacuum relief isolation or containment vacuum relief valves are incapable of performing a containment isolation function."
c.
Change the terminology in the action statement and TS title from
" vacuum relief valve" to " vacuum relief line."
d.
Modify the allowed outage time (A0T) for restoring an inoperable vacuum relief line from 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
In addition to the changes described above, TVA has added information to SQN TS Bases 3/4.6.3 and 3/4.6.6.
The added information provides the basis for the TS requirements and dual design functions associated with SQN's containment vacuum relief system.
Reanga for Change On July 28, 1992 TVA discovered that the configuration of the air supplies and solenoids for SQN's containment vacuum relief isolation valves (air-operated butterfly valves) would result in the loss of guaranteed automatic closure capability upon the unavailability of Train A essential control air, rendering the valves inoperable.
Since Train A essential control air has been unavailable at times over the operating life of the plant without applying the action provisions of j
TS 3.6.3 to the vacuum relief isolation valves, it was concluded that the plant has technically operated in a condition prohibited by TSs. This
n g
_2_
4 finding was reported to NRC in Licensee Event Report (LER) 50-327/92015 l
dated August 27, 1992. Two corrective actions were identified in Section V of the LER.
The first action involved establishing an interim compensatory action to maintain operability of the valves during periods when Train A essential control air is unavailable. The second corrective action involved preparing a TS change to clarify the dual design function of SQN's vacuum relief lines and provide relaxation in the TSs that recognizes the unique nature of this penetration. The enclosed TS change completes the second corrective action.
Other proposed TS changes include the addition of a 72-hour A0T. The other changes are needed to complement the TS changes resulting from the LER and provide consistency with standard TSs (NUREG-1431).
luttification for Changt The EQN vacuum relief system is designed to protect the free-standing steel containment vessel from excessive external force in the event an overcooling or depressurization transient occurs inside containment. The system is sized to ensure that the external pressure differential on the containment vessel does not exceed 0.5 pounds per square inch differential (psid).
System
Description:
The vacuum relief system consists of three identical vacuum relief lines, each comprised of a self-actuating vacuum relief valve, a pneumatically operated isolation valve, associated piping, and instrumentation and controls.
1he three vacuum relief lines are located in the annulus between the primary steel containment vessel and the shield building. The containment penetration numbers associated with these units are X-111
-112, and -113.
The vacuum relief valve is located outboard of the isolation valve as shown on Final Safety Analysis Report (FSAR), Figure 6.2.4-17.
Each vacuum relief valve is a 24-inch, spring-loaded, swing-disc (check) valve with an elastomer seat. The valve is normally closed and is equipped with limit switches that provide fully open and fully closed indication in the main control room (MCR). This instrumentation is designed in accordance with Regulatory Guide (RG) 1.97.
The vacuum relief valve is designed t) start opening at a j
differential pressure of 0.1 psid and to be fully open for a vacuum relief system design basis event.
Each vacuum relief isolation valve is an air-operated butterfly valve with an elastomer seat. Two separate trains of control air are provided to the two separate solenoid valves that control the air supply power to the isolation valve. The isolation valves are normally open, fail-open, and close when the containment pressure increases to the high set pressure of 1.5 pounds per square inch gauge (psig). This isolation signal is developed from either of two
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[ independent pressure sensors for each valve and is completely.
independent of other containment. isolation signals. Fully open and j
- fully closed positions are indicated in the MCR; and if the isolation-valve is not in the fully open position, an alarm is annunciated in the MCR.
'I A complete description of the' design function for this system is provided in the SQN FSAR, Section 6.2.6.
l
~
l Design Bases:
The SQN vacuum' relief system is designed to mitigate the following abnormal operational occurrences:
1.
Inadvertent containment spray actuation l
2.
Inadvertent containment air return fan operation j
3.
Simultaneous occurrence of inadvertent spray and air return fan operation Two of the three vacuum relief lines are required to mitigate the.
[
limiting external dif ferential pressure event (inadvertent spray actuation).
The vacuum relief system is not required to actively mitigate a loss-of-coolant accident (LOCA) or any other accident scenario that might result in the release of radioactivity inside containment. As an extension of the primary containment boundary, the vacuum relief system provides~a barrier against leakage of airborne fission' l
products from the containment atmosphere under normal and accident
'j conditions. The outboard isolation valves are designed to isolate automatically to provide positive containment isolation upon sensing containment pressure greater than or equal to 1.5 psig. The outboard 1
self-actuating check valves are normally closed.
The system is designed to withstand a safe-shutdown earthquake without failure.
Justification:
As discussed in NUREG-1232, Volume 2, page 3-57, the greater safety
. function of SQN's vacuum relief lines and associated isolation valves is to protect the containment vessel from collapse (depressurization j
relative to the annulus) and hence, total loss of containment i
integrity. Based on NRC's evaluation, an exemption to 10 CFR 50, j
General Design Criteria 56 was granted for this unique dual-purpose j
system. The basic conclusion is that the vacuum relief penetrations are designed to ensure containment integrity f rom both an external and internal pressurization event, and the end result is the assurance of containment integrity for all postulated events. As stated in NUREG-1232, "The staff concludes that for Sequoyah, due in part to its low capability to sustain reverse differential pressures, the fail-open position of the butterfly isolation-valves is acceptable."
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The loss of Train A essential control air to the air-operated butterfly isolation valves, as described in LER.50-327/92015, does not result in the loss of containment integrity.
The butterfly valves are designed to fail open from loss of air. Without Train A air, the butterfly isolation valves (air to close) remain in their fail-safe design position (fully open) to fulfill the primary function.of vacuum relief for the containment vessel. The loss of Train A air results in the butterfly isolation valves remaining fully open (with or without Train A single failure). Assuming a single failure occurs to the Train B air supply, the butterfly isolation valves would continue to remain in their fail-safe design position (fully open) since Train B air would not be available to close the valve. With the butterfly valves open, the normally closed spring-loaded vacuum relief check valves would serve as the barrier for containment isolation in the event of an accident.
It is important to note that these vacuum relief check valves are designed to provide a qualified containment boundary against leakage of airborne fission products from the containment atmosphere under normal and accident conditions. Each check valve is leak tested in accordance with 10 CFR 50, Appendix J (Type C test), to ensure the total combined leakage rate from all containment penetrations remains within the maximum allowable leakage rate (0.60 L,).
The containment leak rate assumed in the worst-case design basis accident analysis (LOCA) bounds the 0.60 L leakage limit.
In addition, positive valve position indication is p,rovided in the MCR. The valves are not powered from any electrical source; therefore, no spurious signal or inadvertent operator action could initiate opening these valves. The valves are held closed by a spring force during periods of normal containment pressure and would experience additional closing force from a pressurization event inside containment.
With regard to the current TS Action Statement 3.6.3.b. it is apparent that the condition described in LER 50-327/92015 (loss of Train A air) would require the affected vacuum relief lines to be isolated within four hours or begin unit shutdown. The current TS action requirement would involve closing the affected air-operated butterfly isolation valve (s) and removing electrical power from the valve (s) to fulfill the isolation requirement for the affected line "by use of at least one deactivated automatic valve secured in the isolation position." This action to isolate would be in conflict with SQN TS 3/4.6.6 that requires the vacuum relief line to remain open for operability of SQN's vacuum relief system. To appropriately address provisions for continued operation for the subject lines, TVA proposes to make the following changes to Specifications 3/4.6.3 and 3/4.6.6.
The first proposed change adds a new Action Statement (b) to TS 3/4.6.3 that states:
"b.
With one or more containment vacuum relief isolation valve (s) specified in Sections D.1 through D.3 of Table 3.6-2 inoperable, the Inoperable valve (s) must be returned to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."
- e:
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The purpose of the~above action is to include specific guidance to the operator for the case involving an inoperable containment vacuum relief isolation valve (s). The new action statement provides a.
1 72-hour A0T for restoring the inoperable containment vacuum relief isolation valve (s). These valves are listed in SQN's current TS Table 3.6-2 Section D.
Included with this change is a minor editorial change to the existing action statement to identify it as 1
Action (a) and to specify the sections of. Table 3.6-2 that are applicable.to the (a) action.
The 72-hour A0T is considered appropriate for satisfying the
-containment isolation requirements associated with SQN's vacuum relief lines. For a scenario involving a vacuum relief line having an inoperable vacuum relief isolation valve (i.e., incapable of performing a containment isolation function), the containment isolation requirement for isolating the affected line is satisfied by a closed vacuum relief valve. SQN's vacuum relief valves are normally closed valves that provide a qualified containment isolation i
boundary. The valves are spring-loaded, swing-disk (check) valves with an elastomer seat. The vacuum relief valves are equipped with limit switches that provide fully open and fully closed indication in I
the MCR. These valves are not powered from any electrical source;'
therefore, no spurious signal or operator action could initiate opening of these valves. Accordingly, the addition of a 72-hour A0T.
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within SQN's containment isolation Specification 3.6.3 is considered i
appropriate for satisfying containment isolation requirements while
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actions are taken to return the containment vacuum relief isolation I
j valves to service.
i It should be noted that the 72-hour A0T was selected to be consistent with the A0T from the Westinghouse Electric Corporation standard TS (STS) for vacuum relief valves (reference LCO 3.6.12 of NUREG-1431).
The 72-hour time period for the vacuum relief valves is based on the standard action time for other LOOS involving the loss of one train of a system that is required to mitigate the consequences of a LOCA or other design basis accident.
Included with the. proposed change described above is the addition of SQN's vacuum relief valves to Table 3.6-2.
Addition of.these valves to the table clarifies the containment isolation function that these valves serve. Since these valves are normally closed, self-acting, check valves, a footnote has been included in Table 3.6-2 to note that the maximum isolation time for these valves is not applicable.
n The second proposed change involves SQN TS 3/4.6.6.
Justification for each specific change to TS 3/4.6.6 is described below:
1.
Revise the LCO requirements.
SQN's current LCO states:
"The primary containment vacuum relief valves shall be OPERABLE with an actuation set point of less than or equal to 0.1 PSID" I
- o The proposed change rewords SQN's LCO to-state:
"Three primary containment vacuum relief lines shall be OPERABLE" Rewording the LCO provides language that is consistent with the STS of NUREG-1431 and the SQN design. SQN design assumes single failure of one line such that two of the three vacuum relief lines are required to mitigate the limiting event (inadvertent containment spray actuation). Accordingly, the LCO requirements maintain three vacuum relief lines operable. The STS uses'the words " vacuum relief lines" rather than " vacuum relief valves" in the LCO. This clarification ensures that the individual components of a vacuum relief line (i.e., valves, piping, instrumentation) are encompassed by the LCO requirement.
In addition, the LCO words "with an actuation setpoint of less than or equal to 0.1 PSID" have been removed to be consistent with the STS. This is justified since testing of the vacuum relief valve setpoint is performed under SQN's In-Service Test Program (i.e.,
Surveillance Requirement [SR] 4.0.5 referred to in SQN SR 4.6.6).
2.
Add a footnote to the LCO.
TVA proposes to add a footnote to the LCO to reference the containment isolation valve LCO (LCO 3.6.3).
The proposed footnote is needed for guidance when one or both valves in a containment vacuum relief line are incapable of performing a containment isolation function. The footnote will ensure that appropriate actions are taken in response to a condition that involves a valve (s) within a vacuum relief line that are inoperable for containment isolation.
3.
Modify the A0T.
TVA proposes to modify the A0T for restoring an inoperable vacuum relief line(s) from 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
This proposed change is based on the STS A0T for vacuum relief valves. The 72-hour A0T provides consistent A0T requirements between TVA's newly proposed action requirement for LCO 3.6.3 and LCO 3.6.6.
4.
Modify the TS title and action statement.
TVA proposes to change the terminology in the action statement and TS title from vacuum relief valve to vacuum relief line.
This change is an editorial change that maintains consistent terminology with the STS LCO.
In conclusion, TVA's proposed change provides a TS improvement that p
clarifies the dual design function of SQN's vacuum relief lines and eliminates the potential for misinterpretation regarding the requirements of LCO 3.6.3 and LCO 3.6.6.
In addititn. the TVA design is consistent 1
f with the bases of NUREG-1431.
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Enyironmental Impact Evaluation The proposed change request does not involve an unreviewed environmental question because operation of SQN Units 1 and 2 in accordance with this change would not:
1 1.
Result in a significant increase in any adverse environmental impact previously evaluated in the Final Environmental Statement (FES) as modified by NRC's testimony to the Atomic Safety and Licensing Board, supplements to the FES, environmental impact appraisals, or decisions of the Atomic Safety and Licensing Board.
2.
Result in a significant change in effluents or power levels.
3.
Result in matters not previously reviewed in the licensing basis for.
SQN that may have a significant environmental impact.
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i PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (WA-SQN-TS-93-04, REVISION 2) i DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION i
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Significant' Hazards Evaluation TVA has evaluated the' proposed technical specification (TS) change and has determined that it does not represent a significant hazards j
consideration based on criteria established in.10 CFR-50.92(c).
Operation of Sequoyah Nuclear Plant (SQN) in accordance with the proposed amendment will not:
l 1.
Involve a significant increase in the probability or consequences of an accident previously evaluated.
TVA's proposed TS change does not affect any system functions or design functions. The proposed change addresses the acceptability of.
.l SQN's vacuum relief valves for containment isolation protection, and l
utilizing these normally closed valves for TS-required isolation in the event the associated air-operated butterfly isolation valve (s) is incapable of automatic closure. This approach remains consistent j
with the vacuum relief valve's containment isolation design function.
l.;
SQN's vacuum relief valves (spring-loaded, swing-disk check valves)
I are designed to provide a qualified containment boundary to limit leakage of airborne fission products from the containment atmosphere during normal operation and during an analyzed pressurization event i
inside containment. Each valve is leak tested in accordance with 10 CFR 50, Appendix J'(Type C test), to ensure that the leakage rate-i from the valve (when combined with the leakage rate from all other
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Types B and C containment penetrations) remains within the maximum allowable leakage rate of 0.60 L,.
The containment leak rate assumed in the worst-case design basis accident analysis (loss-of-coolant accident [LOCA]) bounds the 0.60 L, leakage limit.
The vacuum relief valves are normally closed valves and are held closed by a spring force during normal plant operation. The valves 1
would experience additional closing force during a pressurization event inside containment (e.g., LOCA). A review of the design basis events involving containment depressurization indicates that there are no postulated scenarios that would open the vacuum relief valves followed by a LOCA or other accident condition requiring' containment isolation. This containment isolation function remains consistent with the SQN Final Safety Analysis Report Section 6.2.6, and the exemption to 10 CFR 50, General Design Criteria 56, provided in i
'l A 72-hour timeframe for returning an inoperable vacuum relief isolation valve to operable status ensures that redundant isolation capability is restored in a reasonable amount of time. SQN's vacuum relief valves are considered to be highly realible as a containment isolation boundary. Accordingly, the proposed TS change does not involve a significant increase in the probability or consequences of 1
an accident previously evaluated.
The 72-hour allowed outage time for restoring the containment vacuum relief function is consistent with standard TS (STS) bases and does not increase the probability of consequences of an accident j
previously evaluated.
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2.
Create the possibility.of a new or different kind of accident from
- any previously analyzed.
-l No' physical modification is being made'to any plant hardware, plant
' operating setpoints, limits. or operating procedures as a result of-this change.- TVA's proposed change provides a TS improvement that clarifies the configuration and function of SQN's vacuum relief valves as designed. The proposed change removes the potential for creating a conflict between Specification 3/4.6.3, " Containment Isolation Valves," and Specification 3/4.6.6, " Vacuum Relief Valves." SQN's vacuum relief valves provide qualified containment isolation protection that meets the intent of the TS action j
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requirement for containment isolation.
The proposed change does not alter any' accident analysis or any assumptions used to support the accident analyses. The containment 1eakage assumptions used to determine offsite dose limits for compliance with 10 CFR 100 are not affected.
1 A 72-hour timeframe for returning an inoperable vacuum relief isolation valve to cperable status ensures that redundant isolation capability is restored in a reasonable amount'of time.
SQN's' vacuum relief valves are considered to be highly reliable as a containment-isolation bemdary. -Consequently, the proposed change does not create the possibility of a new or different kind of accident from any previously analyzed.
The 72-hour allowed outage time (A0T) for restoring the containment vacuum relief function is consistent with STS bases and does not create the possibility of a new or different kind of accident from any previously analyzed.
3.
Involve a significant reduction in a margin of' safety.
The margin of safety provided by the design of SQN's containment vacuum relief lines remains unchanged. TVA's proposed change does not affect the containment isolation function or the allowable containment leakage rate values specified in the TSs. The proposed change ensures that the proper action is taken in the event the automatic closure capability of the containment vacuum relief
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isolation valve (s) is lost for any reason (improper action would be the isolation of'a vacuum relief line that is required to be operable in accordance with TS 3/4.6.6).
The 72-hour timeframe for returning an inoperable vacuum relief isolation valve to operable status does not reduce the margin of safety because the containment' isolation function is satisfied by qualified vacuum relief valves. The vacuum relief and containment i
isolation functions continue to be maintained under the proposed TS change. Accordingly, the proposed change does not involve a reduction in the margin of safety.
The 72-hour A0T for restoring the containment vacuum relief function is consistent with STS bases and does not reduce the margin of safety.
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