ML20045G780
| ML20045G780 | |
| Person / Time | |
|---|---|
| Site: | 05200001 |
| Issue date: | 06/28/1993 |
| From: | Fox J GENERAL ELECTRIC CO. |
| To: | Poslusny C Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9307150177 | |
| Download: ML20045G780 (27) | |
Text
(
(Q GENuclear Energy GeneratDec:nc Comprw 175 Cunw Annue. San Jose. CA 95125 June 28,1993 Docket No. STN 52-001 s
Chet Poslusny, Senior Project Manager Standardization Project Directorate Associate Directorate for Advanced Reactors and License Renewal Office of the Nuclear Reactor Regulation
Subject:
Submittal Supporting Accelerated ABWR Schedule - Containment Ilypass (Issue #24)
Dear Chet:
Enclosed are SSAR markups addressing Suppression Bypass issue #24. The markups include Section 6.2.1 (Containment Functional Design), Appendix 18A (Emergency Procedure Guidelines), Appendix 18B (Differences Between BWROG EPG Revision 4 and ADWR EPG),
and Appendix 18D (Emergency Procedure Guidelines Input Data and Calculation Results).
This information will be included in Amendment 30, scheduled for transmittal to the NRC on July 8,1993.
Please provide a copy of this transmittal to Mark Reinhart.
Sincerely,
- /
Jack Fox Advanced Reactor Programs cc: Alan Beard (GE)
Norman Fletcher (DOE)
John Monninger (NRC)
JIW 213130163 9307150177 930629 E
gg PDR ADOCK 05200001 S
A PDR jf
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ABWR 23A6100AD Stan6ard Plant wv c above the top row of horizontal vents. The final saturation pressure at the wetwell pressure in the wetwell is lower than the reactor temperature due to the wetwell spray; building pressure because more air is transferred to the drywell during wetwell pressurization than (15) the initial relative humidity in the is received during wetwell depressurization.
drywell is 20%;
The following assumptions are made in (16) initially, the suppression pool is at the analyzing the above event:
High Water Level point; and (1) inerted gas behaves as a perfect gas; (17) the wetwell spray flow rate is 31.51/s.
(2) the temperature in the dryweli remains at For an analysis was conducted with no PCVBS l
57.2 C throughout the transient by means the differential pressure between the wetwell of the drywell cooler; and the reactor buildjng is determined to be negative (-)0.12 kg/cm d. This shows that the l l (3) the initial wetwell temperature is 35 C, stuck open relief valve is a much more severe event than the post-LOCA FWLB transient during (4) the ini;ial containment pressure is 1.03 which the maximurg wetwell negative pressure is kg/cm'a; only 0.06 kg/cm'd. Therefore, the PCV negative pressure requirement on the wetwell y
(5) the maximum suppression pool temperature is part of 0.14 kg/cm can be met without PCVBS.
l 97.2 C; 6
4-
- 1NSERT 6.2.1.1/ Suppression Pool Dpamic Loads 4
(6) werwell spray is from the suppression pool; The containment and its internal structures the initial wetwell spray temperature is are designed to withstand all suppression pool l (7) dynamic effects, including SRV discharge, vent 35 C; clearing and vent chugging. These loads are (8) the capacity of the RHR heat exchanger is combined with those from the postulated seismic events in the load combinations specified in l l
88.45 kcal/sec - C; Subsections 3.8.2.3 and 3.8.3.3.
(9) the maximum wetwell temperature is determined by the maximum wetwc!! spray A diagrammatic representation of the pool temperature and the pool surface heat swell, illustrating various states, is given in transfer to the wetwell airspace; Appendix 3B.
(10) the convective heat transfer coefficient A typical graphical representation of the between the supprepsion pooj and the wetwell dynamic loading due to SRV discharge is found in l
airspace is 9.76 x10 kcal/hr C; Figure 6.2 20. This diagram represents the dynamic loadings for the containment and (11) the mixture of steam and air in the drywell internal structures. The dynamic pressure load is homogeneous such that the ratio of its due to upper vent chugging is found in Figure partial pressures remains constant after the 6.2 21. This load is applicable for structures peak pressure is attained; in the suppression pool area.
7 (12) the air content of the horizontal vent flow 6.2.1.1.$ Asyrnmetric Loading Conditions mixture increases the wetwell pressure; Asymmetric loads are included in the load (13) the drywell pressure is equal to the wetwell combination specified in subsection 3.8.2.3 and pressure when the peak pressure is reached; 3.8.3.3.
The containment and internal structures are designed for these loads within (14) wetwell vapor pressure is equal to the the acceptance criteria specified in Subsections Amendment 29 6.2 12
MM 23A6100AD Standard Plant REV,A 3.8.2.5 an d 3.8.3.5.
Since the internal release data corresponding to a postulated structures are not subject to external design or double ended line break are calculated. The tornado winds, they are not designed for these mass and energy release data, subcompartment loads.
free volumes, vent path geometry and vent loss coefficients are used as input into an analysis Localized pipe forces, pool swell and SRV to obtain the pressure / temperature transient actuation are asymmetric pressure loads which act response for each subcompartment, on the containment and internal structures. For magnitudes of pool swell and SRV loads, see 6.2.1.2.2 Design Features Subsection 6.2.1.1.5.
The upper drywell, lower drywell and wetwell The loads associated with embedded plates are subcompartment volumes are covered in depth in concentrated forces and moments which differ Subsection 6.2.1.1. The remaining containment a cording to the type of structure or equipment subcompartment volumes are:
hing supported. Earthquake loads (OBE and SSE) are inertial loads caused by seismic (1) Dryw-II Hend Recic>n accelerations. The magnitude of these loads is discussed in Section 3.7.
The drywell head region is covered with a 8
removable steel head which forms part of 6.2.1.14 Containment Environment Control the containment boundary. The drywell bulkhead connects the RPV flange to the The drywell ventilation system maintains containment and represents the interface temperature, pressure and humidity in the between the drywell head region and the containment and its subcompartments at the normal drywell.
design conditions. The safety-related containment heat removal systems described in The DBA for the drywell head region is the Subsection 6.2.2 maintain required containment double ended circumferential break of the atmosphere conditions during accidents. Since 6-inch RPV head spray line of the RWCU the loss of the drywell ventilation system does system at the connection to the RPV bead not result in exceeding the design environmental nozzle. The other high energy line in the conditions for the safety-related equipment drywell head region is the 2-in. main steam inside containment, the drywell system is not vent line. The RPV head spray line is classified as safety.related.
chosen as the DBA for this subcompartment S
due to the higher mass and energy release 6.2.1.lg Post. Accident Monitoring rates from a postulated break of this line.
Refer to Subsections 6.2.1.7,7.2,7.3,7.5, (2) Reactor Shield Annulus 7.6.1.2, an d 7.6.1.11 for dis cussio n of instrumentation inside the containment which may The reactor shield annulus exists between be used for monitoring various containment the reactor shield wall (RSW) and the RPV.
parameters under post-accident conditions.
The reactor shield wall is a concrete cylinder surrounding the RPV and is 6.2.1.2 Containment Subcompartments supported by the reactor pedestal.
6.2.1.2.1 Design Bases The annulus surrounding the RPV is sealed at the top of the RSW by a blowout panelin The design of the containment subcompartments the insulation that is assumed to open is based upon the postulated DBA occurring in instantaneously following a postulated each subcompartment.
break of a high energy line inside the annulus.
For each containment subcompartment in which high energy lines are routed, mass and energy Several high energy lines extend from the 6.2-13 A
1 INSERT A 6.2.1.1.5 Steam Bypass of the Suppression Pool 6.2.1.1.5.1 Introduction The concept of the pressure suppression reactor containment is that any steam released from a pipe rupture in the primary system will be condensed by the suppression pool and will not have an opportunity to produce a significant pressurization effect on the containment. This is accomplished by channeling the steam into the suppression pool through a vent system. If a leakage path were to exist between the drywell and the wetwell gas space, the leaking steam would produce undesirable pressurization of the containment. To mitigate the consequences of any steam which bypasses the suppression pool, operator will actuate containment sprays 30 minutes after containment pressure reaches to a defined value.
The following presents the results of calculations performed to determine the allowable leakage capacity between the drywell and wetwell gas space.
i 6.2.1.1.5.2 Criteria The allowable bypass leakage is defined as the amount of steam which could bypass the suppression pool without exceeding the containment design pressure. In calculating this value, a stratified drywell atmosphere model is used to ensure a conservative result. A stratified model will allow steam only flow through the bypass leakage area, thus -
maximizing heatup of the wetwell gas space.
6.2.1.1.5.3 Bypass Capability Without Containment Sprays and Heat Sinks Large primary system ruptures generate high pressure differentials across the assumed leakage paths which, in turn, give proportionately higher leakage flow rates. However, large primary system breaks also rapidly depressurize the reactor and terminate the blowdown. Once this has occurred, there will no longer be a pressure differential across the drywell leakage path, so the containment pressurization due to steam bypass leakage will cease. Since leakage into the wetwell gas space is oflimited duration, the allowable area of the steam bypass leakage paths is expected to be large.
1
)
As the size of the assumed primary system rupture decreases, the magnitude of the differential pressure across any leakage path also decreases. However, smaller breaks are expected to result in an increasingly longer reactor blowdown period, which, in turn, results in longer duration of the steam bypass leakage flow. The limiting case is a sufliciently small primary system break which will not automatically result in reactor depressurization. For this case it is assumed that the response of the plant operator is to shut the reactor down in an orderly manner at 55.6
- C per hour cooldown rate. This would result in the reactor being depressurized and the break flow being terminated within approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. During this 6-hr period, the blowdown flow from the reactor primary system would have swept all the drywell noncondensable gas over into the wetwell gas space. This continuous pressure differential, combined with a 6-hr duration, is expected to result in the most severe drywell-to-wetwell steam bypass leakage requirement.
Based on the above description of a limiting case, a simplified analysis was performed to determine the allowable leakage path area. Consistent with the above description, this analysis assumed that plant operator initiates and completes a normal plant shutdown (at a rate of 55.6* C/hr) in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and there is continuous steam bypass leakage over the entire 6-hr period. A stratified atmosphere model, which assumed steam only flow through the leakage path, was used to ensure conservative result. For an added conservatism, no credit for structural heat sinks and actuation of drywell/wetwell sprays was taken.
Simplified end-point calculations were done to determine maximum allowable area of the leakage paths. Key steps included in this procedure are:
1.
Compute, Mye, mass of noncondensable gas initially in the drywell and the wetwell gas space.
2.
Compute, AP, pressure difference between drywell and wetwell gas space y
needed to keep water level depressed to the top of upper row ofvents.
3.
Compute, Pwy, the maximum allowable pressure in the wetwell gas space.
l
[P AP ],
P
=
ots y
wy i
d
where P.s is the coatainment design pressure.
or 4.
Compute (Pwy )33g, and (Pwy )3ngy components of P wy.
Assume that wetwell gas space temperature is equal to accident maximum pool temperature, and there is complete carryover of drywell noncondensable gas into the wetwell gas space.
[(Pwy )3,g + (Pwu ) STEAM P
=
wy 5.
Compute, hf, mass of steam corresponding to (Pwy )3nay. This defines 3
allowable steam bypass leakage mass into the wetwell gas space.
6.
Compute leakage path flow rate of steam, hiu, as follows:
[(N4K) V(2g,(AP )/v)],
hi
=
y g
where drywell steam specific volume, and v=
K=
totalloss coeflicient of the flow path.
7.
Compute the maximum allowable leakage path area, N4K, as follows:
NE =
[(hfu)/(V(2g,(AP )/v} )
y
[(hi /At)/{V(2g,(AP )/v} ]
=
s y
where Accident duration At
=
Using the procedure outlined above and assuming an accident duration of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, the maximum allowable leakage path area under these circumstances is determined to be an effective flow area (NfK) of 5 cm2 6.2.1.1.5.4 Bypass Capability With Containment Spray and Heat Sinks
An analysis has been perfonned which evaluates the bypass capability of the containment for a spectrum of break sizes considering containment sprays and containment structural heat sinks as means of mitigating the effects of steam bypass of the suppression pool.
The containment system design provides two RHR spray loops, and each loop consists of both wetwell and drywell sprays. In operation of RHR in spray mode, the wetwell and drywell sprays activate simultaneously. Per loop, the design flow rate of drywell spray is 3
3 about 800 m / hour, and that of wetwc!! spray is about 114 m / hour. In this analysis it is assumed that spray is to be initiated no sooner than 30 minutes aller the wetwell gas space pressure is reached to 1.05 kg/cm g. This assumed value of spray initiation pressure set 2
2 point, which is higher than the EPGs pressure set point of 0.7 kg/cm g, s expected to produce slightly conservative results. The suppression pool water passes through the RHR heat exchanger and is then injected into the drywell and wetwell spray headers located respectively in the upper region of drywell and wetwell gas space. The spray will rapidly condense the stratified steam, creating a homogeneous air-steam mixture in the containment. Structural heat sinks (drywell and wetwell boundary surfaces) were considered with variable convective heat transfer coefficients based on Uchida correlation.
The reactor vessel shutdown rate was assumed to be 55.6' C/hr, and the maximum design service water temperature was used. This shutdown rate corresponds to the maximum rate which does not thermally cycle the reactor vessel. This analysis results in an allowable maximum steam bypass leakage capability of A/R of 50 cm, meeting the 2
criterion that calculated maximum containment pressure remain below the containment design pressure. Maximum steam bypass capability vs primary system break area is shown in Figure 6.2-w 4 2.
The key assumptions for allowable steam bypass calculations utilizing stmetural heat sinks are summarized as follows:
(1)
Following the occurrence of a pipe line break within the drywell, air is purged through the vents into the wetwell.
(2)
Flow through the postulated leakage path is pure steam. For a given leakage path, if the leakage flow consists of mixture ofliquid and vapor, the total leakage mass flow rate'is higher, but the steam flowrate is less than for the case of pure steam leakage. Since the steam entering the wetwell air space results in the additional pressurization, this is considered as a conservative assumption.
(3)
The containment sprays are manually actuated 30 minutes after the wetwell airspace pressure reaches to 1.05 kg/cm2 g.
(4)
Credit for wetwell spray only was taken. Considering that wetwell spray is more effective in mitigating consequences of steam bypass leakage, credit i
for drywell spray was not taken to produce conservative results.
l R
(5)
The efficiency of the sprays is dependent upon the local steam-to-air ratio.
A conservative constant value of 0.7 was used in this analysis.
(6)
Heat is transferred to exposed drywell/wetwell concrete walls (with steel liner)in the drywell and wetwell gas space regions. The Uchida convective heat transfer coefficients used are based on the local steam-to-air ratio.
(7)
No energy is assumed to leave the containment except through the RHR heat exchangers.
h The following is an illustration of the methods employed in calculating steam condensing capability under typical post-LOCA conditions. The condensation capability is calculated using the following equation:
hi = hi, x N, x [(T - T,)/Hrg] x C c
c p
where steam condensation rate; hi
=
c spray flow rate; hi,
=
spray efficiency; N,
=
containment temperature; T
=
e spray temperature at the spray nozzles; T,
=
Hrg latent heat of vaporization of water; and
=
constant pressure specific heat of water.
C
=
p The spray water temperature is calculated from:
t KHX x [( T - Ty ) /( hi, x C )]
T, T
=
p p
p where suppression pool temperature; T
=
p KHX =
RHR heat exchanger effectiveness; and T,
semce water temperature
=
Containment sprays have a significant effect on the allowable steam bypass capability. Use of sprays increases the maximum allowable bypass leakage by an order of magnitude and represents an effective backup means of condensing bypass steam.
1 0.2 --
.- l M
I g
'd 0.15 ~ -
U' n.<U OE 0.1 -
j,
- =
-<w A
WJ k
0.05 --
- o AA<
0 l
l l
0 0.25 0.5 0.75 -
1 1.25 1.5 PRIMARY SYSTEM BREAK AREA (sq ft)
Figure 6.2-Allowable Steam' Bypass. Leakage Capacity
'j 4 2.
'l l
I b;
1
-ABWR m6ima Standard Plant arv. 4 DW/T Monitor and control drywell temperature below [57.2 *C (drywell temperature LCO or maximum normal operating temperature, whichever is higher)] usir.g available drywell cooling.
When drywell temperature cannot be maintained below
[57.2 *C (drywell temperature LCO or maximum normal se #1 operating temperature, whichever is higher)], shutdown the reactor.
DWrr.1 Operate all available drywell cooling, defeating isolation interlocks if necessary.
When drywell temperature cannot be maintained below
[103'C (Saturation temperature corresponding to high drywell pressure scram setpoint)], enter [ procedure developed from the RPV Control Guideline) at (Step RC-1] and execute it concurrently with this procedure.
f l
c,., t a m.. u e If while executing the following steps W sprays have been initiated and drywell pressure drops below [0.12 kg/cm2 g (high drywell pressure scram setpoint)], termmate sisymmeH sprays.
6/27M3 t'o n te uM W ABWR PC-4 Amendment 22 18 A.5-4 l
.a p
e.
--a.
,n.--
- - - - - - - - - - ~
4 ABWR uwmia Standard Plant asy. 4 DW/T-2 Before drywell temperature reaches (171 C (maximum temperature at which ADS qualified or drywell design temperature, whichever is lower)] but only if suppression pool water levelis below (11.70 m (elevation of bottom of suppression pool-to-lower-drywell vent)) and drywell temperature and pressure are within the Drywell Spray "4 nitiation Limit, shut down drywell cooling fans and initiate I
CO AdameH sprays using only those RHR subsystems (RHR(B),
RHR(C)) not required to assure adequate core cooling by.
continuous operation in the LPCF mode.
codommuk Cw& ws.mV If RHR(B)
RHR(C) are not available forW sprays, initiate 4: !! sprays using the fire protection system and firewater additon mode of RHR(C). F0lbo6b Q
Geto DRYWELL SPRAY ITIATION LIMIT y
44f bf*
W~
}
on W
j 3M
/
Do Noi START n HowM g
lh.
L d
,, G (rue bu.40
/
g
/
- h #
8 50 X g(_ w/
Ll6.3 -* -go C ".0 c
0 0.5 d
1.0
.5 20 2.s 30 DRYWELL PRESSURE (kg/cm2)
I o.al o.g ABWR PC-5 IBA55 Arnendment 24 7
b/z1/93
ABWR momia Standard Plant arv. 4 2
PC/P Monitor and control primary containment pressure below [0.12 kg/cm g (high dryw cli pressure scram setpoint >] using the following systems:
SGTS RBHVAC, and nitrogen vent and purge only if containment pressure is less than [0.14 kg/cm2 g (SGTS and RBHVAC design pressure)]; use [ containment vent and purge operating procedures].
2 When primary containment pressure cannot be maintained below [0.12 kg/cm g (high drywell pressure scram setpoint)], or the offsite radioactivity release rate reaches the offsite release rate LCO isolate the primary containment vent and purge.
If while executing the following steps su pool sprays have been 2
initiated and suppression ch
. ssure drops below [0.12 kg/cm g (high drywell pressu setpoint)], terminate suppression pool sprays.
,/
Before suppression chamber pressure reaches [0.728 kh 1
(Suppression Chamber Spray Initiation Pressure)], but only i N
suppression pool water level is below [18.90 m (el 1 of I
suppression pool spray nozzles)], initiat ression pool sprays using only those RHR subsyste R(B), RHR(C)) not irquired to assure adequate co ing by continuous operation in the LPCF mode.
\\
.R(B) and RHR(C) are not available for suppression pool sprays, initiate suppression pool sprays using the fire protection 7
/
tem and the firewater addition mode of RHR(C)
- $ h\\ehh - vik GffC4Y(L kG b5UV-]
ABWR PC 7 l
18 A 5 7 Amendment 24 fl
h h
-k-,a.
4 e
a a
s ABWR
- uuim, Standard Plant
- m.,,
-i
(.$uffrY%rcs cl%wber of i
\\
Cnha nn wk if while exectiting the following steps dpfwel sprays have been initiated angrywell pressure drops below [012 kg/cm2 g (high.
drywell pressure scram setpoint)], terminat I sprays.-
,W wsk PC/P-2 When suppression chamber pressure exceeds [0.728 kg/cm2 g (Suppression Chamber Spray Initiation Pressure)) but only if suppression pool water level is below [11.70 m (elevation of bottom t
of suppression pool-to-lower-4rywell vent)) and drywell g4 d.
temperature and pressure are within the Drywell Spray I non Limit, shutdown drywell cooling fans and initiate sprays using only those RHR subsystems (RHR(B) RHR(C)) not required to assure adequate core cooling by continuous operation in the LPCF
{
t
- mode, (AhlH d'i Ch
[
If RHR(B d RHR(C) are not available for defweesprays, I
initiate sprays using the fire protection system and the l
firewater addition mode of RHR(C).
.i 1
DRYWELL SPRAY INITIATION LIMIT y
110 m
i 10 - O f
~
)
+:/
l w
3::-
f if DO N0f START f_.))MYWELLSPAAYS
?
ft
~
AO 70
/.f. A k
. /
9 l
"- /
j g
a f,
s D
40 0.0 0.5
- 1.0 1.5 2.0 2.s 3,0 -
0.33 1 46 DRYWELL PRESSURE (kWcm2) l
.q ABWR PC-8 I
IIA 3'I Amendment 24 t a?D
ABWR 2u6ima Standard Plant gty.,
PC/P-6
' When suppression chamber pressure cannot be maintained below
[(the Primary Containment Pressure Limit)], then irrespective of whether adequate core cooling is assured:
i PRIMARY CONTAINMENT PRESSURE LIMIT i
n iTAAT SPRAYS l 5
56 d$'
W l
$o 2
E 1
b m
0 0
5 10 is 20 25 30 k
PRIMARY CONTAINMENT WATER LEVEL tm) o
/
if suppression pool water level is below [18.90 m (elevation of suppression pool spray nozzles)] initiate suppression 4
pool sprays. Suppression pool sprays may be augmented by the fire protection system and the firewater addition mode of HR(C).
G [lf suppression pool water level is below [11.70 m (elevation of bottom of suppression pool-to-lower-drywell vent)]
j
- and drywell temperature and pressure are within the Drywell Spray initiation Limit, shut down drywell cooling fans and initiate
- sprays, spray J may be augmented by t e fire protection syst and the I
i firewater addition m e of RHR(C).
Qgg,w r covkwak i
ABWR PC-10 18 A.$- 10 Amendmem 24
( w
9 ABWR
- 23xaiooA, Standard Plant any.,
PC/H-4 When dryw ell or suppression chamber hydrogen concentration reaches 6% and drywell or suppression chamber oxygen concentration is above 5%, EMERGENCY RPV DEPRESSURIZATION IS REQUIRED.
c ~ +. u - +- -
If while executing the following steps syr.a :.. m; m. J., - 2 sprays have been initiated andN<ey Ebc reIsu drops below [0.12 kg/cm2 g pprd=
(high drywell pressure scram setpoint)], terminate bter.ead.
peeFsprays.
Dry;c;" nn cenn amne vinm m n gg,,,;, (; ;, g, uc;;_ o_
p"'""
= = c p a'i] te d.r.:d.,_;;;,7,,,p (
f suhression pool water level is below [l 8.90 mA PC/H-4.1 (elevation of suppression pool spray nozzles)], initiate suppression pool sprays using only those RHR subsystems (RHR(B),RHR(C))not re to assure adequate core cooling by conti operationin the LPCF mode.
\\
\\
_ If RHR(B
. RHR(C) are not available for ssion pool sprays, initiate suppression pool
\\
su prays using the fire protection system and the fi ewate ddition mode of RHR(C).
(DeleM - uoi applcoMe to A8%Rp A
ABWR PC 20 18 A.$.20 Amendment 24 1
- u y iOD,
Standard Plant guy.,
PC/H-4.2 (Deleted - not applicable to ABWR.)
1 PC/H-4.3 (Deleted not applicable to ABWR.)
PC/H-4.4 If suppression pool wate. evelis below (11.70 m
. (elevation of bottom of suppression pool-to-lowerwirywell vent)] and drywell temperature, and pressure are within the Drywell Spray Initiation g Limit, shut down drywell cooling fans and initiate g3 Pj x!! sprays using only those RHR subsystems -
(RHR(B), RHR(C)) not required to assure adequate core cooling by continuous operation in the LPCF mode.'
to b w &
If RHR(B) and RHR(C) are not available for ej'd sprays, initiate sprays using the fire protection system and the 11 ater addition mode of RHR(C).
h 46th m a+f-DRYWELL SPRAY INITIATION LIMIT -
'y 110 10 3
?[
W DO NoT START go 5
\\
DRYWELL YS l,
N, A
?!
l":
/
e
/
6ee j se0 2
s 50
()
V 0.0 05 1.0 1.5 2D 2.5 30:
A 0.33 14 DRYWELL PRESSURE (kg/cm2)
I fC i
i a
ABWR PC-21
\\
18A.5-21 Amendment 24
---___,w
,m_..ew a
w w,
r-r wr.,r-, - - -, - -.
1, r m
-4,+i-,
u
-sw-
-g
ABWR 2mi.m Standard Plant asy.x PC/H-5 When drywell or suppression chamber hydrogen concentration cannot be restored and maintained below 6% and drywell or suppression chamber oxygen concentration cannot be restored and maintained below 5%, then irrespective of whether adequate core cooling is assured:
(cm+Qwt M &
If while executing the following steps ; rr -5Eva r-vl 021 - "
7 sprays have beeninitiated ang uppression chambeppre/sure\\ldrops below [0.12 kg/cm2 g oc w we (high drywell pressure scram setpoint)], terminate ;;xx!::
kc=4*id*=P
-peal sprays.
^
Uj'//^'! p- ::5 i r bO'aO'# IbI2 hMId ^ (I5N i'i'#J0'I
- r
- : = :.. x.
.y....,j, w. --- 1,
".r. _y:. o-PC/H-5.1 Jf m;t :: !c: p^^! -eter Sve! !: M!c?' [!" M =
l
(:!:/d:::f: ;;;xir: p::!:7;j r.;,;. '=)],!9 '-
c' ;;x:: :. r;~! -r.:.y;. -
(DeteW - ucF opplimbk fo ASWEd t
k E
-1
]
i b
ABWR PC 22 1
IsA.5-22 h m 22 4
s ABWR m ima i
Standard Plant aEv. 4 i
PC/H 5,2 If suppression pool water level is below (11,70 m (elevation of bottom of suppression -
pool-to-lower-drywell vent)] and drywell temperature and pressure are within the Drywell Spray Initiation Limit, shut down drywell cooling fans and initiate
- sprays, CN44 tvf vt4@i DRYWELL SPRAY INITIATION LIMIT 110
,]g,7; r]g4,;;g;
[
[
105
._ ; 7
-) q wss n-g@M
.C
';I f.
' 1,% Gig. [,q7
~
Qw ooagm y
w;'::r-e oaywEtts m v
e.v,.
. n,.en w
n,
- - ',,;^
l
- Y b
i$$
66.6 -
~
60 W
/
s s
,e A
^3 Od l
V 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.33 1.46 DRYWELL PRESSURE (kt,/cm2) r eqc/ g ABWR PC-23 h
L Amendment 22 18 A.S.23 1
1
- i 1
ABWR umma Standard Plant
,,y,
TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG qQ" Jg alf fmys w n. %ao& "qq.
ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES b ttu 464/2)dgwaI cd WprewG-< {AOf EPG STEP EPG REV. 4 BWROG REV.4 EPG 5p hra 6 cu+ yi b d 9 &, Wwomvava umM, Y
/ m/
STEP 3
n L,0
- ) Replaced phrase, of I I
. In the ABWR containment, vents are provided DWfr-2 DWfr-2
+
" elevation of bottom of connecting the upper drywell to the lower internal suppression drywell. When the wetwell-to-drywell vacuum chamber to drywell breakers open, flow is from the wetwell to the vacuum breakers less lower drywell and then from the lower drywell to vacuum breaker opening the upper drywell through these vents. The pressure in feet of water",
vaccum breakers are located above the vents.
with the phrase, Water can also spill to the lower drywell from the "elevauon of the bottom suppression poolif poollevel reaches the vents.
of suppression pool-to-Water can also flow from the lower drywell to the lower-drywell vent" suppression pool if lower drywell is flooded to the elevation of thse vents. For these reasons, it is appropriate to spray the drywell only when suppression pool water level is below the bottom of the upper drywell to lower drywell vents to preclude drywell differential pressure capability to be exceeded.
The ABWR has internal recirculation pumps, Deleted phrase
+
" recirculation pumps" driven by motors located below the RPV in the from instruction to lower portion of the drywell. Drywell spray only shutoff recirculation sprays the upper portion of the drywell. An pumps and drywell explicit instnaction to shut down the recirculation cooling fans prior to pumps is not required.
hpray initiation.
p g,g g
RHR subsystems B and C provide,41rywell and N"
- Specify RHR pumps used f
for pray as spray capability. Initiation ofprays is "RHR ubsystems B and by manual control action. It is potsible to C".
initiate spray when RHR B or C is operating in
@MQ other modes by opening spray valves.
The firewater addition system is described in Specified the use of the a
firewater addition system Subsection 5.4.7.1.1.10. The specific purpose of if RHR(B)and RHR(C) the fire addition system is to provide makeup to are not available for the RPV to extend the station blackout capability of the ABWR, but it can be used for drywell and
@-sprays.
wetwell sprays if no other systems are available Cg% 4 for sprays.
op 7 ;,>
II M Amendment 22
t ABWR 23naiooxa Standard Plant arv 4 TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV 4 BWROG REV. 4 EPG STEP DW/T-3 DW/T-3
. Deleted phrase:" enter This phrase has been moved to Step DW/r-1.
[ procedure developed from Reactor scram is specified under the same the RPV Control instruction in DW/r-1 prior to reaching the Guideline) at [ Step RC-1 temperature as stated in Step DW/r-2.
and execute it concurrently with this procedure".
PC/P PC/P Added instruction to Venting is performed only if containment permit venting through pressure is less than the design pressure of these SGTS and RBHVAC
" soft vent" systems to preclude damage to these only if containment system equipment, and venting through these pressure is less than the system for pressure control is allowed if design pressure of these radioactivity release rate is less than the LCO systems. Also, venting limit.
through these systems is to be terminated if containment pressure exceed the design pressure of these systems or if offsite release rate exceed h the release rate LCO.
v PC/P-1 PC/P-1 ete the
?--- p_-- = ej g=; gy,m _,,
Sup ssi Pres 3.u.4 m ;w,,
,,,,g,
- pyss,
)
1
[
ssi c ber De Me /)8tvR.dr we( M y l j
g g g,49c m g l tui v s u l
ss
's v
.2 psig a
imit]
,,p gg gr4 g(g, g
g,j Peci um usei._ ?:: 6 fu,I,Vi,7-; s u, A I
{r e s l
.no spef ed u T*hG hw M(Cuc b V O B"
Im Fire ater
'tio cum 4iW8 /a PC/IP'd 1
Sy.em r spra if R
p6,4.fc //o.ss,
[
&C no vailable j
or sprays.
s
)
heleN & dire-
)
j et
\\
9eg.
\\
s Cod vft[L o OctT 68#$
fA b4SM Fo +cr y 4s 6psap S% PC/P-Q w.w., n
.beA e supressm gg
( %sw en g7 d
. W Go a o t'C -
/
ABWR ux6imia Standard Plant any.,
TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG Qqlatsh")c4w<lI f% O C O '4 Y b'
ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV. 4 BWROG REV. 4 EPG STEP Replaced phrase,
- See bases for DW/T-2 above.
PC/P-2 PC/P-2
" elevation of bottom of internal suppression chamber to drywell vacuum breakers less vacuum breaker opening pressure in feet of water",
with the phrase,
" elevation of the bottom of suppression pool +
lower # ell vent".
Deleted phrase "recurulation pumps" from insuuction to shutoffrecuculation Pumps and drywell cooling fans prior to 9%y initiation.
spra wed S
RHR pumps used for spray as "RHR subsystems B and C" and specified using the Firewater Addition System for sprays if RHR B & C are not available for sprays.
4
$1 N I8B-9 Amendarnt 22 I
ABWR' naima Standard Plant any 4 TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV. 4 BWROG REV 4 EPG STEP er PC/P-6 PC/P-64. SpeciSed that In the ABWR, venting the containment is not to be performed since containment integrity is containment sprays may l, be augmented by the nre assured by the rupture diaphragms as discussed water addition system.
above under basis for PC/P-4. In the unlikely
/
event that the rupture diaphragms have not been l
actuated when containment pressure exceeds the i
l Primary Containment Pressure Limit [ pressure at I
which the diaphragms are expected to actuate),
/
- then it is appropriate to spray the wetwell and the drywell in an attempt to reduce containment i
pressure to maintain containment integrity.
The firewater addition system may be aligned to spray the wetwell and the drywell.
(
- %&bW weU
, 3,Q sy,m j
u,s p m. L. $ a dN f oo l M k"' m h
Ik,w Ja.
- w. w i
p ue we, The lo% elev. w cf Ae o
k%a d suppssw pl-k-lcus c-dywell ved(il,70N e
an,9 Le elevahen ab hse
$4gr,tS6/G+^ f#dl won /'s(if.fo-2 6 ud as & calov;aw pet usakr e \\suu 4,w fce m%e
- c spray twkW.
l[
"$$5 Anundment 22 18B-10.1
ABWR usiwan Standard Plant
,3y 4 l
p TABLE 18B-1 (Cont'd)
)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV. 4 BWROG REV. 4 EPG STEP Replaced the phrase
- A system is injecting water into the primary SP/L-3.1 SP/L-3.1
" terminate injection into containment if all the following enteria are the RPV from sources satisfied:
external to the primary containment" with the (1) The suction source of the system is outside phrase, " terminate the pnmary contalment, and injection into the primary (2) The system penetrates the primary containment from sources contaiment, and external to the pnmary (3) The system discharge is adding to the containment",
primary containment water inventory (i e., a system is injecting into the RPV and either the RPV has an unisolated leak inside the primary containment or the safety relief valves are open to the primary containment.
The function of the Primary Containment Water Limit is to preclude containment failure.
Systems that inject into the RPV is a subset of those systems that ce inject into the primary containment. It has always been the intent of the existing wording to direct the termination of all injection into the primary containment from sources external to the primary containment.
Tt.e new wording of the injectin termination statement is also intended to allow RPV injection to continue if no water is leaving the RPV into the pnmary containment.
l 1 B B-11.1 Amenstment 22
ABWR ua6iwan Standard Plant un TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV,4 BWROG REV 4 EPG STEP PCSI-4 PC/H-4 Deletedinstruction for Venting at this step through SGTS and a
vent and purging of the RBHVAC ( " soft vents") with high oxygen and primary containment hydrogen concentrations is not to be perfomied to when oxygen and -
preclude potential structural damage to these hydrogen concentrations equipment due to combustion or explosions.
reaches the level specified in this step.
Deleted phrase," enter
- This phrase has been moved to Step PC/H-2.1.
[ procedure developed from Refer to the bases for Step PCai-2.1.
the RPV Control Guideline) at (Step RC-1 and execute it concurrently with this 3 pro =dum" y
%ify RHR pup {fs
- Sr ts. Im Sp D""" 2. Tw &< ASE PC/H-4.1 PCal-4,I
/
for suppressiorpool jp// d gu g,
/ [bs
- " " '"SI
& C and to fd8/(W8edly ' f
- tom
/.
l up(FAS if RHR B and N'
"'c b b C Cf i
k1sre not availabl TL cw foru,%f ega7 M@m
~
i i
PC/H-4.2
/H-4.2 Deleted step.
Venting is not to be performed as discussed above under basis for Step PC/H-4.
/
PC/H
.3 PC/H-4.3 Deleted step.
Purging is not applicable because the venting instructions have been deleted.
CWY'lH#h 'j ttWdruel1 15
{
%....q Pc/n -s v.
. o.wq.
ms f
N
~
/ < 6-brw8 C#rrded
. % h,,,, Q Qg k// -%!
C
/
he - ca yrda s usa ~ suce w
c%bec or cigwil l
i g
ms r
t...t,
._ _ m f,h 1
h 1:
,. i ABWR 2 mima Standard Plant ar u TABLE 18B-1 (Cont'd)
DIFFERENCES BETWEEN BWROG EPG REVISION 4 AND ABWR EPG ABWR BWROG DIFFERENCES FROM BASIS FOR DIFFERENCES EPG STEP EPG REV. 4 BWROG REV 4 EPG STEP PC/H-4.4 PC/H-4,4
- Deletedreferenceto
- See discussion of basis for step DW/r-2.
recirculation pumps and specified RHR pumps
' C M W ced b used for 1, Jiih y as RHR subsystems B and C; added instruction to use FAS if RHR B and C are not available.
See discussion of basis for step DW/r-2.
Replaced phrase,
" elevation of bottom of internal suppression chamber to drywell vacuum breakers less vacuum breaker opening pressure in feet of water',
(
with the phrase, L)b@
" elevation of the bottom of suppression pool-to-lower-drywell vent".
g See discussion of basis for step DW/r-2.
Deleted reference to PC/H-5.2 PC/H-5.2 recirculation pumps.
See discussic,n of basis for step DW/r-2.
Replaced phrase,
" elevation of bottom of internal suppression chamber to drywell vacuum breakersless yacuum breaker opening pressure in feet of water",
with the phrase,
" elevation of the bottom of suppression pool-to-lower-drywell vent".
G.a.c.y&"dy%a.,y+. & be,sn Gc sp Pc/'a-c. '
e t( "
pW%
Tj$
l 5%s
-.~.: n
'dmn i
V)
M gjp.g \\
gc/p-C i
(. caw-l) Gxcrks
- 6ex bcses C-c h kr" *W 6He PC/H-5. ),
fgens b3w sa
\\
Su pp Ss>w c aber\\
I CrclgvMllpn55vrt
\\
)
Olekb sisp.
- Z< he &Bwe, dy u)*H jy-5t Pcj'N-5 t n() %pp ressiw cw-ber M4 IkQS 6frA
's s~an~4.sey y n n iare s~vy 0pu&D. The cw%wwf spray m,b h wsh= %
b cw ktvirD ts Ghg Pc/N -5 a-
\\,
t N
ill I
-I l
1 ABWR u aimAa.
Standard Plant 1
arv. 4 -
TABLE 18D.2-1 (Cont.)
BWROG EPG REV. 4 APPENDIX C RESULTS FOR ABWR PARAMETER VALUE PARAMETER DEFINITION j
MARFP SRVs.
MARFP Minimum Alternate RPV Flood Pressure (kulem2) 8 or more 9.48 j
7 10.98 6
12.98 5
15.78 4
19.99 3
27.00 2
40.99 MCFI SRVs MCFI Minimum Core Flooding Interva!
L"I QMd 8 or more 43.9 7
59.9 6
84.8 WLl_1 Highest DW Minimum Indicated Water LevelInstrument Number 1:
Run Temn. (*C) level (cm)
Shutdown (345.3 to 1272.3 cm)
T Lax High 65.6 426.5
?
65.6 121.1 439.9 121.1 176.7 458.2 176.7 232.2 482.1 j
232.2 287.8 514.6 WLI_2 Highest DW MinimumIndicated Water LevelInstrument Number 2:
Run Temn (*C) 12 vel (emi Narrow Range (345.3 to 497.8 cm) l LQE High 3
65.6 389.6 f
65.6 121.1 382.5 121.1 176.7 372.9 176.7 232.2 360.7 232.2 287.8 345.3 l
DWSIL Drywell Dqwell Drywell Spray Initiation Limit m$
(See Figure in Section 18A.5) 1 0.21 46.3 0.28 81.9 0.33 105.4
-GM C#0
,,313.-l 3f./
[
,s i
44t- 0.'t7 Jmr173.)
t 1l ons- 0.S1
.ssa.90'21
.c.89 Oh/
.so+ W3#
,A'73 i
-He-o.6 f 47-t-280.1 i/
1,a o.7C
.7n zo1.C
-+-M--
H-r-
?
4,46-
.MHr-l
.,3.o&-
41Mf' 18D.2-3 Amendment 22
- -, - - _ - _ _ _ - _ _