ML20196G050
| ML20196G050 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/25/1997 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20196G046 | List: |
| References | |
| NUDOCS 9705130293 | |
| Download: ML20196G050 (13) | |
Text
._._ _ _
Programs and Manuals 5.5 '
5.5 Programs and Manuals 5.5.15 Safety Function Determination Prooram (SFDP)
(continued)
The SFDP identifies where a loss of safety function exists.
If a loss of safety function is determined to exist by this
)rogram, the appropriate Conditions and Required Actions of the.C0 in which the loss of safety function exists are required to be entered.
5.5.16 Containment Leakaae Rate Testino Proaram A program shall' be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50. Appendix J. Option B. as modified by approved exemptions.
This program shall be in accordance with the guidelines contained in Regulatory Guide 1.163. September 1995, as modified by the following exception: NEI 94-01. Revision 0.
Section 9.2.3. is modified to permit the elapsed time between the first and the last tests in a series of consecutive satisfactory tests to be at least 18 months.
The peak calculated containment internal ~ pressure for the design basis loss of coolant accident. P, is 44.4 psig*. The containment
(
design pressure is 50 psig.
The maximum allowable containment leakage rate. L,. at P,. shall i
be 0.10% of containment air weight per day.
Leakage Rate acceptance criteria are:
a.
Containment leakage rate acceptance criterion is 51.0 L,.
During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are < 0.60 L, dfor the Type B and C tests and < 0.75 L, for Type A tests; an Q (ja t } ploe b Yy e 0 an'I N'I' V GIff d
f Ja 7 and affe- ( W,Y psq fo-nt2)
C, Cy (continued) g i
BYRON - UNITS 1 & 2 5.0-35 h ision A 4
bR Dbk0500b54 P
PDR j
Containment-B 3.6.1' l
j i
BASES 4
4 BACKGROUND a.
All penetrations required to be closed during accident (continued) conditions are either:
)
1.
capable of being closed by an OPERABLE automatic containment isolation system. or 2.
closed by manual valves, blind flanges, or 4
de-activated automatic or remote manual valves secured in their closed positions, except as j
provided in LC0 3.6.3 " Containment Isolation l
Valves":
b.
Each air lock is OPERABLE. exce)t as provided in LCO 3.6.2. " Containment Air Loc(s": and c.
The equipment hatch is closed.
APPLICABLE The safety design basis for the containment is that the SAFETY ANALYSES containment must withstand the pressures and temperatures of the limiting DBA without exceeding the design leakage rate.
E" The DBAs that result in a challenge to containment
~
OPERABILITY from high pressures and temperatures are a LOCA and a steam line break (Ref. 2).
In addition. release of-significant fission product radioactivity within containment can occur from a LOCA. secondary system pipe break, or fuel handling accident (Ref. 3).
In the DBA analyses, it is assumed that the containment is OPERABLE such that, for the DBAs involving release of fission product radioactivity, release to the environment is controlled by the rate of containment leakage.. The containment was designed with an allowable leakage rate of 0.10% of containment air weight
.hj(Aft /p,oc per day (Ref. 3). This leakage rate, used to evaluate offsite doses resulting from accidents. is defined in 10 CFR 50. Appendix J. Option B (Ref.1). as L the g C c/,7
,,c f maximum allowable containment leakage rate at f.:he calculated i
V f
ak containment internal pressure (P ) resulting from the
>tfj'g83'7 NmitingdesignbasisLOCA. The allowable leakage rate C/ ahb represented by L : forms the basis for the acceptance
{fcfe 4 (f,,,12)I criteria imposed,on all containment l i
, is to i
r Q
_)
a I
j (continued)
BYRON - UNITS 1 & 2 B 3.6-2
-Revision A-g
.,-,.m.,.
..,e n.
n,.,.
~
Containment Air Locks B 3.6.2' BASES (continued)-
APPLICABLE The DBAs that result in a release of radioactive material
[
SAFETY ANALYSES within containment are a Loss Of Coolant' Accident (LOCA),
secondary system pipe break, and a fuel handling accident (Ref. 2).
In the analysis of each of these accidents, it is assumed that containment is OPERABLE such that-release of fission products to the environment is controlled by the rate of containment leakage. The containment was designed with an allowable leakage rate of 0.1% of containment air weight per day (Ref. 2). This leakage rate is defined in i
10 CFR 50, Appendix J. Option B (Ref.1). as the maximum-allowable containment leakage rate at the calculated peak containment internal 3ressure, P, 44.4 psiaafollowina a l
design basis LOCA. T11sallowabieleakagefateformsthe basis for the acceptance criteria imposed on-the SRs i
associated with the air locks.
The containment air locks satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LC0 Each containment air lock forms part of the containment l.
pressure boundary. As part of the containment pressure
! (_
boundary, the air lock safety function is related to control of the containment leakage rate resulting from a DBA. Thus, each air lock's structural integrity and leak tightness are j
essential to the successful mitigation of such an event.
Each air lock is required to be OPERABLE. For the air lock to be considered OPERABLE, the air lock interlock mechanism must be OPERABLE, the air lock must be in compliance with l
the Type B air lock leakage test, and both air lock doors must be OPERABLE.
The interlock allows only one air lock door of an air lock to be opened at one time. This-provision ensures that a gross breach of containment doer.
not exist when containment is required to.be OPERABLE.
Closure of a single door in each air lock is sufficient to i
provide a leak tight barrier following postulated events.
Nevertheless, both doors are kept closed when the air lock is not being used for normal entry into or exit from containment.
h,.t l p, co.-- b &cIe. ? ad 4'7a f Siff
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kyale % dafter-i i
(continued)
BYRON - UNITS 1 & 2 B 3.6-8 Rc'/ icier A
Containment Pressure B 3.6.4 BASES APPLICABLE The initial pressure condition used in the containment 1
SAFETY ANALYSIS analysis was 0.3 psig.
Evaluations performed showed that if l
(continued) the initial pressure was raised to 1 psig the maximum peak pressure from a LOCA was 44.4 asidV The containment l
analysis (Ref.1) shows that t1e maximum peak Calculated containment pressure, Pa. results from the limiting LOCA.
The maximum containment pressure resulting from the worst case LOCA, 44.4 psigh' does not exceed the containment design pressure. 50 psig.
The containment was also evaluated for an external pressure l
load equivalent to -3.5 psig (Ref. 2). The inadvertent i
actuation of the Containment Spray System was analyzed to determine the resulting reduction in containment pressure.
The initial )ressure condition used in this analysis was r
1 h d,a C / wo do 0.0 psig. T11s resulted in a minimum pressure inside
/
inment of -3.48 psig, which is less than the design gg Er yo/e'TaaJ 8 For certain aspects of transient accident analyses.
((qy,y#7)44,r{d maximizing the calculated containment pressure is not conservative.
In particular, the cooling effectiveness of 3
the Emergency Core Cooling System during the core reflood s.~
phase of a LOCA analysis increases with increasing containment backpressure. Therefore, for the reflood phase, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the containment pressure response in accordance with 10 CFR 50, Appendix K (Ref. 3).
Containment pressure satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).
LC0 Maintaining containment pressure at less than or equal to the LC0 upper pressure limit ensures that, in the event of a DBA, the resultant peak containment accident pressure will remain below the containment design pressure. Maintaining containment pressure at greater than or equal to the LCO lower pressure limit provides reasonable assurance that the containment will not exceed the design negative differential pressure following the inadvertent actuation of l
the Containment Spray System.
l t
1 (continued) l BYRON - UNITS 1 & 2 B 3.6-34 h isicn A 1
i s
Containment Air Temperature i
B 3.6.5 '-
l BASES 3
APPLICABLE The limiting DBAs considered relative to containment SAFETY ANALYSIS OPERABILITY are the LOCA und SLB; The DBA LOCA and SLB are (continued) analyzed using computer codes designed to predict the resultant containment pressure transients.
No two DBAs are assumed to occur simultaneously or consecutively. The postulated DBAs are analyzed with regard to Engineered Safety Feature (ESF) Systems, assuming the loss of one ESF bus, which is the worst case single active failure, resulting in one train each of the Containment Spray System.
Residual Heat Removal System, and Containment Cooling System being rendered inoperable.
The limiting DBA for the maximum peak containment air temperature is an SLB. The initial containment average air temperature assumed in the design basis analyses (Ref.1) is 120*F. This resulted in a maximum containment air.
temperature ofy. The design temperature is 280'F.
7 The temperature limit is used to establish the environmental qualification operating envelope for containment. The maximum mak containment air temperature was calculated to exceed t1e containment design temperature for only a few seconds during the transient. The basis of the containment design temperature, however, is to ensure the performance of safety related equipment inside containment (Ref. 2).
Thermal analyses showed that the time interval during which the containment air temperature exceeded the containment l
design temperature was short enough that the equipment 1
surface temperatures remained belok the design temperature.
Therefore, 1t is concludd that the calculated transient containment air temperature is acceptable for the DBA SLB.
1 The temperature limit is also used in the depressurization analyses to ensure that the minimum pressure limit is maintained following an inadvertent actuation of the Containment Spray System (Ref. 1).
(continued)
BYRON - UNITS 1 & 2 B 3.6-38 M 5 M A --
_.._ ~ -.
~
Containment Spray and Cooling Systems i
B 3.6.6' i
BASES.(continued)'
APPLICABLE The Containment Spray System and Containment Cooling System SAFETY ANALYSES limit the tem mrature and pressure that could be experienced following a D3A. ~ The limiting DBAs considered are the Loss Of Coolant Accident (LOCA) and the Steam Line Break (SLB).
[
The LOCA and SLB are analyzed using computer codes designed to predict the resultant containment pressure and 1
temperature transients.
No DBAs are assumed to occur simultaneously or consecutively. The mstulated DBAs are analyzed with regard to containment ES systems, assuming the loss of one ESF bus, which is the worst case single active failure and results in one train of the Containment
~
Spray System and Containment Cooling System being rendered inoperable.
i The analysis and evaluation show that under the worst case scenario, the highest mak containment pressure is 44.4 psigy (exmrienced during a.0CA). The analysis shows that the l
[jlf,7'y peac containment temperature isy:nTr (experienced during an l
SLB). Both results meet the intent of the design basis.
(See the Bases for LCO 3.6.4, " Containment Pressure," and LC0 3.6.5 for a detailed discussion.) The analyses and evaluations assume a unit specific power level of 3579 MWt, l.
one containment spray train and one containment cooling L
train operating, and initial (pre-accident) containment conditions of 120*F and 0.3 psig.
Evaluations were performed that showed if the initial pressure was raised to 1 psig the maximum peak pressure would be 44.4 psigY The l
analyses also assume a response time delayed initiation to provide conservative peak calculated containment pressure and temperature responses.
l For certain aspects of transient accident analyses, maximizing the calculated containment pressure is not l
conservative.
In particular, the effectiveness of the Emergency Core Cooling System during the core reflood phase of a LOCA analysis increases with increasing containment backpressure.
For these calculations, the containment backpressure is-calculated in a manner designed to conservatively minimize, rather than maximize. the calculated transient containment pressures in accordance l
with 10 CFR 50, Appendix K (Ref. 4).
l
.foc doit I pewc b 0 ele 7ed '/7 B sy & lydc T t
aa dkc (w.99 6 a.t a) l (continued) r I
l BYRON - UNITS 1 & 2 B 3.6-44 Unie,. A i
t ATTACHMENT B-2a MARKED UP PAGES FOR PROPOSED CHANGES TO IMPROVED t
l TECHNICAL SPECIFICATIONS OF FACILITY OPERATING LICENSES L
i BRAIDWOOD STATION UNITS 1 & 2 l
REVISED PAGES:
1 5.0-35 B 3.6-2 B 3.6-8 B 3.6-34 B 3.6-38 i
B 3.6-44 i
l t
i I
l t
l l-e i
i
' Programs anj Manuals.
l 5.5 7
5.5 Programs and Manuals 5.5.15 Safety Function Determination Proaram'(SFDP)- (continued)
?
The SFDP identifies where a loss of safety function exists.
If a i
loss of safety function is determined to exist by this
- 3rogram, the appropriate Conditions and Required Actions of the _C0 in which the loss of safety function exists are required to be entered.
I 5.5.16 Containment Leakaae Rate Testina Proaram l
A program shall be established to implement the leakage rate i
testing of the containment as required by 10 CFR 50.54(o) and-i 10 CFR 50.~A exemptions. ppendix J, Option B.- as modified by approved -This progra
_ guidelines contained in Regulatory Guide 1.163. September-1995, as i
modified by the following exception:
NEI 94-01. Revision 0, Section 9.2.3, is modified to permit the elapsed time between the 1
first and the last tests in a series of consecutive satisfactory tests to be at least 18 months.
The peak calculated containment internal. pressure for the design p
basis loss of coolant accident, P, is 44.4 psigY The containment q
design pressure is 50 psig.
j The maximum allowable containment leakage rate, L,. at P., shall be 0.10% of containment air weight per day.
Leakage Rate acceptance criteria are:
I a.
Containment leakage rate acceptance criterion is s 1.0 L,.
During the first unit startup following testing in accordance with this program. the leakage rate acceptance criteria are < 0.60 L, dfor the Type B and C tests and < 0.75 L, for Type A tests; an
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je g e J a & c.~
O W p sig & ll a t
l l
l I
(continued) l BRAIDWOOD - UNITS 1 & 2 5.0-35 h isien A l
i l-
l Containment
~
l B 3.6.1 '
BASES All penetrations required'to be closed during accident 4
l l
BACKGROUND a.
(continued) conditions are either:
l'.
capable of being closed by an OPERABLE automatic containment isolation system. or i
2.
closed by manual valves, blind flanges, or de-activated automatic or remote manual valves secured in their closed positions, except as provided in LCO 3.6.3. " Containment Isolation valves":
b.
Each air lock is OPERABLE. exce)t as provided in LCO 3.6.2. " Containment Air Loccs"; and c.
'The equipment hatch is closed.
l The safety design basis for the containment is that the APPLICABLE SAFETY ANALYSES containment must withstand the pressures and temperatures of the limiting DBA without exceeding the design leakage rate.
l []
The DBAs that result in a chall to containment i
OPERABILITY from high pressures temperatures are a LOCA and a steam line break (Ref. 2).
In addition, release of l-significant fission product radioactivity within containment I
can occur from a LOCA. secondary system pipe break, or fuel j
handling accident (Ref. 3).
In the DBA analyses, it is assumed that the containment is OPERABLE such that, for the l
DBAs involving release of fission product radioactivity, release to the environment is controlled by the rate of 3
containment leakage. The containment was designed with an
( g,,'.p [ /#"
allowable leakage rate of 0.10% of containment air weight I
L 7"r t
per day (Ref. 3). This leakage rate, used to evaluate g {)'J g 3J offsite doses resulting from accidents. is defined in 10 CFR 50. Appendix J. Option B (Ref.1) as L
- the l
47'/ 5'8 4'
/-
maximum allowable containment leakage rate at fhe calculated ak containment internal pressure (P ) resulting from the
{[g g y efter
$miting design basis LOCA. The allowable leakage rate t
represented by Lj forms the basis for the acceptance CygyNf g,,. 6;M]J criteria imposed on all containment leakage rate testing.
L, is assumed to be 0.10% per day in the safety analysis at f
P, = 44.4 psigjhf. iM.
q l
(M 3)
(
t J
(continued) l-I BRAIDWOOD - UNITS 1 & 2 B 3.6-2
%imn '
_,m. _,
~
Containment Air Locks l
B 3.6.2' BASES (continued)
APPLICABLE The DBAs that result in a release of radioactive material SAFETY ANALYSES within containment are a toss Of Coolant Accident (LOCA),
secondary system pipe break, and a fuel handling accident (Ref. 2).
In the analysis of each of these accidents. it is i
assumed that containment is OPERABLE such that release of fission products to the environment is controlled by the rate of containment' leakage. The containment was designed with an allowable leakage rate of 0.1% of containment air weight per day (Ref. 2). This leakage rate 'is defined in 10 CFR 50, Appendix J. Option B (Ref.1), as the maximum allowable containment leakage rate at the calculated peak containment internal 3ressure, P, 44.4 psigYfollowino a design basis LOCA. T11s allowable leakage rate forms the basis for the acceptance criteria imposed on the SRs associated with the air locks.
The containment air locks satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LC0 Each containment air lock forms 3 art of the containment aressure boundary. As part of t1e containment pressure aoundary, the air lock safety function is related to control of the containment leakage rate resulting from a DBA. Thus, each air lock's structural integrity and leak tightness are essential to the successful mitigation of such an event.
Each air lock is required to be OPERABLE.
For the air lock to be considered OPERABLE, the air lock interlock mechanism must be OPERABLE, the air lock must be in compliance with l
the Type B air lock leakage test, and both air lock doors
]
must be OPERABLE. The interlock allows only one air lock door of an air lock to be opened at one time. This provision ensures that a gross breach of containment does not exist when containment is required to be OPERABLE.
Closure of a single door in each air lock is sufficient to provide a leak tight barrier following postulated events.
Nevertheless, both doors are kept closed when the air lock is not being used for normai entry into or exit from containment.
ff, &C lpn b Cyde 8 a+d V74sio 0 l
l
[yc/e 8 a.J affe,- (W Ypsig 4 doY h (continued)
BRAIDWOOD - UNITS 1 & 2 B 3.6-8 Rsision A' l
l
Containment Pressure B 3.6.4~
BASES APPLICABLE The initial pressure condition used in the containment SAFETY ANALYSIS analysis was 0.3 psig.
Evaluations performed showed that if (continued) the initial pressure was raised to 1 psig the maximum peak pressure from a LOCA was 44.4 )siaY The containment-c s
l analysis (Ref.1) shows that t1e maximum peak. calculated containment pressure, Pa results from the limiting LOCA.
The maximum containment pressure resulting from the worst case LOCA, 44.4 osidf does not exceed the containment design pressure, 50 psig.
L The containment was also evaluated for an external pressure load equivalent to -3.5 psig (Ref. 2). The inadvertent actuation of the Containment Spray System was analyzed to determine the resulting reduction in containment pressure.
7 The initial 3ressure condition used in this analysis was
[c daif / / Her b 0.0 psig. T11s resulted in a minimum pressure inside g /, B,J W psig (inmentof-3.48psig,whichislessthanthedesign geJd%
i b
For certain aspects of transient accident analyses, (yy,y f;1 4r &f k maximizing the calculated containment pressure is not p
conservative.
In particular, the cooling effectiveness of 1
the Emergency Core Cooling System during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. Therefore, for the reflood phase, the containment backpressure is calculated in a manner designed to conservatively minimize. rather than maximize, the containment pressure response in accordance with
.10 CFR 50, Appendix K (Ref. 3).
Contain'nent pressure satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).
LCO Maintaining containment pressure at less than or equal to the LC0 upper pressure limit ensures that, in the event of r
a DBA, the resultant peak containment accident pressure will remain below the containment design pressure.
Maintaining containment pressure at greater than or equal to the-LC0 lower pressure limit provides reasonable assurance that the containment will not exceed the design negative differential pressure following the inadvertent actuation of the Containment Spray System.
I (continued)
L BRAIDWOOD - UNITS 1 & 2 B 3.6-34
-Revision-A-
..m,,,m
,m a
+
m...
e
Containment Air Temperature, i
~
B 3.6.5 -
j
[
BASES APPLICABLE The limiting DBAs considered relative to containment SAFETY ANALYSIS OPERABILITY are the LOCA and SLB. The DBA LOCA and SLB are (continued) analyzed using computer codes designed to predict the resultant containment pressure transients.
No two DBAs are assumed to occur simultaneously or consecutively. The 1
postulated DBAs are analyzed with regard to Engineered i
Safety Feature (ESF) Systems, assuming the loss of one ESF bus.-which is the worst case single active failure, resulting in one train each of the Containment Spray System.
Residual Heat Removal System, and Containment Cooling System being rendered inoperable.
4 i
The limiting DBA for the maximum peak containment air 4
I i
temperature is an SLB. The initial containment average air temperature assumed in the design basis analyses (Ref.1) is i]
oh]
C 120'F. This resulted in a maximum containment air temperature of 4182F. The design temperature is 280*F.
4 The temperature limit is used to establish the environmental
~
qualification operating envelope for containment. The j
maximum mak containment air temperature was calculated to exceed t1e containment design temperature for only a few seconds during the transient. The basis of the containment design temperature however, is to ensure the performance of f
O" safety related equipment inside containment (Ref. 2).
Thermal analyses showed that the time interval during which the containment air temperature exceeded the containment design temperature was short enough that the equipment i
4 surface temperatures remained below the design temperature.
Therefore. it is concluded that the calculated transient containment air temperature is acceptable for the DEA SLB.
The temperature limit is also used in the depressurization analyses to ensure that the minimum pressure limit is
)
maintained following an inadvertent actuation of the Containment Spray System (Ref. 1).
i (continued)
BRAIDWOOD - UNITS 1 & 2 8 3.6-38 Pavision a
Containment Spray and Cooling Systems B 3.6.6' 4
BASES (continued)
APPLICABLE The Containment Spray System and Containment Cooling System SAFETY ANALYSES limit the tercerature and pressure that could be experienced following a DEA. The limiting DBAs considered are the Loss Of Coolant Accident (LOCA) and the Steam Line Break (SLB).
The LOCA and SLB are analyzed using computer codes designed to predict the resultant containment pressure and temperature transients.
No DBAs are assumed to occur simultaneously or consecutively. The 3ostulated DBAs are analyzed with regard to containment ES: systems, assuming the loss of one ESF bus, which is the worst case single active failure and results in one train of the Containment Spray System and Containment Cooling System being rendered inoperable.
The analysis and evaluation show that under the worst case scenario, the highest )eak containment pressure is 44.4 psigY l
(ex>erienced during a _0CA). The analysis shows that the 319.7 F naac containment temoerature isYSt8af (experienced during an d
SLB).
Both results meet the intent of the design basis.
(See the Bases for LCO 3.6.4. " Containment Pressure." and LCO 3.6.5 for a detailed discussion.) The analyses and evaluations assume a unit specific power level of 3579 MWt.
one containment spray train and one containment cooling train operating, and initial (pre-accident) containment conditions of 120*F and 0.3 psig.
Evaluations were performed that showed if the initial pressure was raised to 1 psig the maximum peak pressure would be 44.4 psigY The l
analyses also assume a response time delayed initiation to provide conservative peak calculated containment pressure and temperature responses.
1 For certain aspects of transient accident analyses.
maximizing the calculated containment pressure is not conservative.
In particular, the effectiveness of the 1
Emergency Core Cooling System during the core reflood phase of a LOCA analysis increases with increasing containment J
backpressure.
For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize the l
calculated transient containment pressures in accordance with 10 CFR 50. Appendix K (Ref. 4).
0 c/e 8 and Y7,fpsig
,_ (,T l fnon b:
7 cte 6 a a die-Lw. yp,;g 4.- u~ r A)
(continued)
BRAIDWOOD - UNITS 1 & 2 B 3.6-44 Rev m un A i