ML20138K892
| ML20138K892 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/11/1997 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Philadelphia Electric Co |
| Shared Package | |
| ML20138K895 | List: |
| References | |
| NPF-39-A-122, NPF-85-A-086 NUDOCS 9702190197 | |
| Download: ML20138K892 (16) | |
Text
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UNITED STATES j
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. SpeeHoot
\\...../
PHILADELPHIA ELECTRIC COMPANY DOCKET NO. 50-352 LIMERICK GENERATING STATION. UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No.122 License No. NPF-39 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Philadelphia Electric Company (the licensee) dated September 27, 1996, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (1) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
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l 9702190197 970211 PDR ADOCK 05000352 l
P PDR i
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[ 2.
Accordingly, the license is amended by changes to the Technical l
Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-39 is hereby l
amended to read as follows:
Technical Soecifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 122, are hereby incorporated into this license.
Philadelphia Electru Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
3.
This license amendment is effective as of its date of issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION
(
Je
'F. Stolz, D rector frejectDirectorateI-Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specification,s Date of Issuance: February ;i
'L997 th 1
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ATTACHMENT TO LICENSE AMENDMENT NO.122 FACILITY OPERATING LICENSE NO. NPF-39 DOCKET NO. 50-312 Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by Amendment number and contain vertical lines indicating the area of change.
Remove Insert 3/4 6-46 3/4 6-46 3/4 6-53 3/4 6-53 3/4 6-54 3/4 6-54 8 3/4 6-5 B 3/4 6-5 B 3/4 6-6 B 3/4 6-6 i
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CONTAINMLNT SYSTEMS
'3/4.6.5 SECONDARY CONTAINMENT j
REACTOR EhCLOSURE SECONDARY CONTAINMENT INTEGRITY LIMITING C0h3ITION FOR OPERATIO1 3.6.5.1.1 REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY shall be maintained.
APPLICABILITY:
OPERATIONAL CONDITIONS 1, 2, and 3.
ACTION:
Without REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY, restore REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE RE0VIREMENTS 4.6.5.1.1 REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY shall be demon-strated by:
a.
Verifying at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that the pressure within the reactor enclosure secondary containment is greater than or equal i
to 0.25 inch of vacuum water gauge.
b.
Verifying at least once per 31 days that:
\\
1.
All reactor enclosure secondary containment equipment hatches and blowout panel: sra closed and sealed.
2.
At least one door in each access to the reactor enclosure secondary containment is closed.
1 l
3.
All reactor enclosure secondary containment penetrations not capable of being closed by OPERABLE secondary containment auto-matic isolation dampers / valves and required to be closed during accident conditions are closed by valves, blind flanges, slide gate dampers or deactivated automatic dampers / valves secured in
- position, c.
At least once per 24 months:
1.
Verifying that one standby gas treatment subsystem will draw down the reactor enclosure secondary containment to greater than or equal to 0.25 inch of vacuum water gauge in less than or equal to 916 seconds with the reactor enclosure recirc system in operation l
and i
2.
Opcrating one standby gas treatment subsystem for one hour and maintaining greater than or equal to 0.25 inch of vacuum water i
gauge in the reactor enclosure secondary containment at a flow rate not exceeding 2500 cfm with wind speeds of s 7.0 mph as l
)
measured on the wind instrument on Tower 1, elevation 30' or,
{
if that instrument is unavailable, Tower 2, elevation 159'.
LIMERICK - UNIT 1 3/4 6-46 Amendment No. S, 77, IOS, 122
'f
' CONTAlltiENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) b.
At least once per 24* months or (1) after any structural maintenance on the HEPA filter or charcoal adsorber housings, or (2) following painting, fire, or chemical release in any ventilation zone communicating with the subsystem by:
1.
Verifying that the subsystem satisfies the in-place penetration L
and bypass leakage testing acceptance criteria of less than 0.05%
and uses the test procedure guidance in Regulatory Positions C.5.a, C.5.c and C.5.d of Regulatory Guide 1.52, Revision 2, March 1978, i
and the system flow rate is 5764 cfm 10%.
l 2.
Verifying within 31 days after removal that a laboratory analysis of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory Position C.6.a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than 0.175%; and 3.
Verify that when the fan is running the subsystem flowrate is 2800 cfm minimum from each reactor enclosure (Zones I and II) and 2200 cfm minimum from the refueling area (Zone III) when tested in accordance with ANSI N510-1980.
4.
Verify that the pressure drop across the refueling area to SGTS prefilter is less than 0.25 inches water gage while operating at a flow rate of 2400 cfm i 10%.
c.
After every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of charcoal adsorber operation by verifying within 31 days after removal that a laboratory analysis of a repre-sentative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory Position C.6.a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than 0.liS%.
d.
At least once per 24 months by:
1.
Verifying that the pressure drop across the combined HEPA filters and charcoal adsorber banks is less than 9.1 inches water gauge while operating the filter train at a flow rate of 8400 cfm i 10%.
- Surveillance interval is an exception to the guida cn e provided in Regulatory Guide l
1.52, Revision 2, March 1978.
LIMERICK - UNIT 1 3/4 6-53 Amendment NO. 6, 33, 71, 122
' CONTAINMENT SYSTEMS
. SURVEILLANCE REQUIREMENTS (Continued) 2.
Verifying that the fan starts and isolation valves necessary to draw a suction from the refueling area or the reactor enclosure recirculation discharge open on each of the following test signals:
a)
Manual initiation from the control room, and b)
Simulated autor,atic initiation signal.
3.
Verifying that the timperature differential across each heater is a 15*F when tested in accordance with ANSI N510-1980.
e.
After each complete or partial replacement of a HEPA filter bank by verifying that the HEPA filter bank satisfies the inplace penetration and leakage testing acceptance criteria of less than 0.05% in accordance with ANSI N510-1980 while operating the system at a flow rate of 5764 cfm 10%.
l f.
After each complete or partial replacement of a charcoal adsorber bank by verifying that the charcoal adsorber bank satisfies the inplace penetration and leakage testing acceptance criteria of less than 0.05%
in accordance with ANSI N510-1980 for a talogenated hydrocarbon refrigerant test gas while operating the system at a flow rate of 5764 cfm i 10%.
l g.
After any major system alteration:
1.
Verify that when the SGTS fan is running the subsystem flowrate is 2800 cfm minimum from each reactor enclosure (Zones I and II) and 2200 cfm minimum from the refueling area (Zone III).
2.
Verify that one standby gas treatment subsystem will drawdown i
reactor enclosure Zone I secondary containment to greater than or equal to 0.25 inch of vacuum water gauge in less than or equal to 916 seconds with the reactor enclosure recirculation l
system in operation and the adjacent reactor enclosure and refueling area zones are in their isolation modes.
l LIMERICK - UNIT 1 3/4 6-54 Amendment No. 40, 106, 122
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CONTAlfftENT SYSTEMS
. BASES 3/4.6.5 SECONDARY CONTAINMENT l
l Secondary containment is designed to minimize any ground level release of radioactive material which may result from an accident. The Reactor Enclosure and associated structures provide secondary containment during normal operation l
when the drywell is sealed and in service. At other times the drywell may be open and, when required, secondary containment integrity is specified.
Establishing and maintaining a vacuum in the reactor enclosure secondary containment with the standby gas treatment system once per 24 months, along with i
the surveillance of the doors, hatches, dampers and valves, is adequate to ensure that there are no violations of the integrity of the secondary containment.
The OPERABILITY of the reactor enclosure recirculation system and the standby gas treatment systems ensures that sufficient iodine removal capability will be avcilable in the event of a LOCA or refueling accident (SGTS only). The reduction in containment iodine inventory reduces the resulting. SITE BOUNDARY radiation doses associated with containment leakage. The operation of this system and resultant iodine removal capacity are consistent with the assumptions used in the LOCA and refueling accident analyses.
Provisions have been made to continuously purge the filter plenums with instrument air when the filters are not in use to prevent buildup of moisture on the adsorbers and the HEPA filters.
Although the safety analyses assumes that the reactor enclosure secondary containment draw down time will take 930 seconds, these surveillance require-ments specify a draw down time of 916 seconds. This 14 second difference is due to the diesel generator starting and sequence loading delays which is not i
part of this surveillance requirement.
The reactor enclosure secondary containment draw down time analyses assumes
)
a starting point of 0.25 inch of vacuum water gauge and worst case SGTS dirty j
filter flow rate of 2800 cfm.
The surveillance requirements satisfy this as-sumption by starting the drawdown from ambient conditions and connecting the adjacent reactor enclosure and refueling area to the SGTS to split the exhaust flow between the three zones and verifying a minimum flow rate of 2800 cfm from the test zone. This simulates the worst case flow alignment and verifies ade-quate flow is available to drawdown the test zone within the required time.
The Technical Specification Surveillance Requirement 4.6.5.3.b.3 is intended to be a multi-zone air balance verification without isolating any test zone.
The SGTS fans are sized for three zones and therefore, when aligned to a single zone or two zones, will have excess capacity to more quickly drawdown the affected zones. There is no maximum flow limit to individual zones or pairs of zones and the air balance and drawdown time are verified when all three zones are connected to the SGTS.
~
The three zone air balance verification and drawdown test will be done i
after any major system alteration, which is any modification which will have an effect on the SGTS flowrate such that the ability of the SGTS to drawdown
~ the reactor enclosure to greater than or equal to 0.25 inch of vacuum water gage in less than or equal to 916 seconds could be affected.
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LIMERICK - UNIT 1 8 3/4 6-5 Amendment No. 6, #1, 7Y, ydd, 122 i
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CONTAllMENT SYSTEMS BASES 3/4.6.5 5ECONDARY CONTAINMENT (Continued)
The field tests for bypass leakage across the SGTS charcoal adsorber and HEPA filter banks are performed at a flow rate of 5764 i 10% cfm.
The laboratory 1
j analysis performed on the SGTS carbon samples will be tested at a velocity of 66 fpm based on the system residence time.
}
The SGTS filter train pressure drop is a function of air flow rate and filter conditions. Surveillance testing is performed.using either the SGTS or j
drywell purge fans to provide operating convenience.
Each reactor enclosure. secondary containment zone and refueling area secondary containment zone is tested independently to verify the design leak tightness. A design leak tightness of 2500 cfm or less for each reactor l
i enclosure and 764 cfm or less for the refueling area at a 0.25 inch of vacuum tater gage will ensure that containment integrity is maintained at an 1
acceptable level if all zones are connected to the SGTS at the same time.
The Reactor Enclosure Secondary Containment Automatic Isolation Valves l
and Refueling Area Secondary Containment Automatic Isolation Valves can be fcund in the UFSAR.
The post-LOCA offsite dose analysis assumes a reactor enclosure secondary centainment post-draw down leakage rate of 2500 cfm and certain post-accident l
X/Q values. While the post-accident X/Q values represent a statistical inter-pretation of historical meteorological. data, the highest ground level wind speed which can be associated with these values is 7 mph (Pasquill-Gifford stability Class G for a ground level release).
Therefore, the surveillance requirement assures that the reactor enclosure secondary containment is verified under meteorological conditions consistent with the assumptions utilized in the design basis analysis.
Reactor Enclosure Secondary Containment leakage tests that are successfully performed at wind speeds in excess of 7 mph would also satisfy the leak rate surveillance requirements, since it shows compliance with more conservative test conditions.
i 3/4.6.6 PRIMARY CONTAINMENT ATMOSPHERE CONTROL The OPERABILITY of the systems required for the detection and control of 1
hydrogen combustible mixtures of hydrogen and oxygen ensures that these systems will be available to maintain the hydrogen concentration within the primary containment below the lower flammability limit during post-LOCA conditions.
The primary containment hydrogen recombiner is provided to maintain the oxygen concentration below the lower flammability limit. The combustible gas analyzer is provided to continuously monitor, both during normal operations and post-LOCA, the hydrogen and oxygen concentrations in the primary containment.
The primary containment atmospheric mixing system is provided to ensure adequate mixing of the containment atmosphere to. prevent localized accumulations of hydrogen and oxygen from exceeding the lower flammability limit. The hydrogen control system is consistent with the recommendations of Regulatory Guide 1.7, " Control of Combustible Gas Concentrations in Containment. Fa', lowing a LOCA," March 1971.
LIMERICK - UNIT 1 B 3/4 6-6 Amendment No. 8, 703, 122
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p UNITED STAGS s
j NUCLEAR REGULATORY COMMISSION j
2 WASHINGTON, D.C. 20066-4001
's.,...../
PHILADELPHIA ELECTRIC COMPANY DOCKET NO. 50-353 LIMERICK GENERATING STATION. UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 86 License No. NPF-85 1.
The Nuclear Regulatory Comission (the Comission) has found that:
A.
The application for amendment by Philadelphia Electric Company (the licensee) dated September 27, 1996, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Comission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Comission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Comission's regulations; D.
The issuance of this amendment will not be inimical to the comon defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Comission's regulations and all applicable requirements have been satisfied.
I 4
i
'. 2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-85 is hereby amended to read as follows:
Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 86
, are hereby incorporated in the license.
Philadelphia Electric Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
3.
This license amendment is effective as of its date of issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION
(
n LL oh V. Stolz, Direct Pr ect Directorate I-2 Di ision of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance:
February 11, 1997
I ATTACHMENT TO LICENSE AMENDMENT NO. 86 FACILITY OPERATING LICENSE NO. NPF-85 DOCKET NO. 50-353 l
Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by Amendment number and contain vertical lines indicating the area of change.
Remove Insert 3/4 6-46 3/4 6-46 3/4 6-53 3/4 6-53 3/4 6-54 3/4 6-54 B 3/4 6-5 B 3/4 6-5 B 3/4 6-6 B 3/4 6-6
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' CONTAllMENT SYSTEMS
,3/4.6.5 SECONDARY CONTAINMENT REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY l
l LIMITING ColWITION FOR OPERATION i
3.6.5.1.1 REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY shall be maintained.
L APPLICABILLIll.
OPERATIONAL CONDITIONS 1, 2, and 3.
f ACTION:
{
i Without REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY, restore REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
l SURVEILLANCE REQUIREMENTS 4.6.5.1.1 REACTOR ENCLOSURE SECONDARY CONTAINMENT INTEGRITY shall be demon-strated by:
a.
Verifying at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that the pressure within the reactor enclosure secondary containment is greater than or equal l
to 0.25 inch of vacuum water gauge.
b.
Verifying at least once per 31 days that:
1.
All reactor enclosure secondary containment equipment hatches and blowout panels are closed and sealed.
2.
At least one door in each access to the reactor enclosure secondary containment is closed.
3.
All reactor enclosure secondary containment penetrations not capable of being closed by OPERABLE secondary containment auto-matic isolation dampers / valves and required to be closed during accident conditions are closed by valves, blind flanges, slide gate dampers or deactivated automatic dampers / valves secured in position.
c.
At least once per 24 months:
1.
Verifying that one standby gas treatment subsystem will draw down the reactor enclosure secondary containment to greater than or L
equal to 0.25 inch of vacuum water gauge in less than or equal to l
916 seconds with the reactor enclosure recirc system in operation, l
and l
2.
Operating one standby gas treatment subsystem for one hour and maintaining greater than or equal to 0.25 inch of vacuum water gauge in the reactor enclosure secondary containment at a flow rate not exceeding 2500 cfm with wind speeds of s 7.0 mph as l
L measured on the wind instrument on Tower 1, elevation 30' or, l
if that instrument is unavailable, Tower 2, elevation 159'.
I I
LIMERICK - UNIT 2 3/4 6-46 Amendment No. Ill, #, 86
CONTAINMENT SYSTEMS
. SURVEILLANCE REQUIREMENTS (Continued) b.
At least once per 24* months or (1) after any structural maintenance on the HEPA filter or charcoal adsorber housings, or (2) following painting, fire, or chemical release in any ventilation zone communicating with the subsystem by:
1.
Verifying that the subsystem satisfies the in-place penetration I
and bypass leakage testing acceptance criteria of less than 0.05%
and uses the test procedure guidance in Regulatory Positions C.S.a, C.5.c and C.S.d of Regulatory Guide 1.52, Revision 2, March 1978, and the system flow rate is 5764 cfm i 10%.
l 2.
Verifying within 31 days after removal that a laboratory analysis i
of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory Position C.6 a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than 0.175%; and 3.
Verify that when the fan is running the subsystem flowrate is 2800 cfm minimum from each reactor enclosure (Zones I and II) and 2200 cfm minimum from the refueling area (Zone III) when I
tested in accordance with ANSI N510-1980.
4.
Verify that the pressure drop across the refueling area to SGTS prefilter is less than 0.25 inches water gage while operating at a flow rate of 2400 cfm i 10%.
l c.
After every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of charcoal adsorber operation by verifying within 31 days after removal that a laboratory analysis of a repre-sentative carbon sample obtained in accordance with Regulatory-Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory dosition C.6.a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than 0.175%.
d.
At least once per 24 months by:
1.
Verifying that the pressure drop across the combined HEPA filters and charcoal adsorber banks is less than 9.1 inches water gauge while operating the filter train at a flow rate of 8400 cfm i 10%.
- Surveillance interval is an exception to the guidance provided in Regulatory Guide 1.52, Revision 2, March 1978.
(
LIMERICK - UNIT 2 3/4 6-53 Amendment No. 34, 86
'CONTAllMENT SYSTEMS SURVEILLANCE RE00IREMENTS 'Contiiued)
Z.
Lerifying ". hat tie fan starts and isolation valves necessary to draw a suction from the refueling area or the reactor enclosure recirculation discharge open on each of the following test signals:
a)
Manual initiation from the control room, and b)
Simulated automatic initiation signal.
3.
Verifying that the temperature differential across each heater is a 15'F when tested in accordance with ANSI N510-1980.
e.
After each complete or partial replacement of a HEPA filter bank by verifying that the HEPA filter bank satisfies the inplace penetration and leakage testing acceptance criteria of less than 0.05% in accordance with ANSI N510-1980 while operating the system at a flow rate of 5764 cfm i 10%.
l f.
After each complete or partial replacement of a charcoal adsorber bank by verifying that the charcoal adsorber bank satisfies the inplace penetration and leakage testing acceptance criteria of less than 0.057 in accordance with ANSI N510-1980 for a halogenated hydrocarbon refrigerant test gas while operating the system at a flow rate of 5764 cfm i 10%.
l g.
After any major system alteration:
1.
Verify that when the SGTS fan is running the subsystem flowrate is 2800 cfm minimum from each reactor enclosure (Zones I and II) and 2200 cfm minimum from the refueling area (Zone III).
2.
Verify that one standby gas treatment subsystem will drawdown reactor enclosure Zone 11 secondary containment to greater than or equal to 0.25 inch of vacuum water gauge in less than or equal to 916 seconds with the reactor enclosure recirculation l
system in operation and the. adjacent reactor enclosure and refueling area zones are in their isolation modes.
LIMERICK - UNIT 2 3/4 6-54 Amendment No. W, 86 1
' CONTAllMENT SYSTEMS l
. RASES
[
j-3/4.6.5 SECONDARY CONTAINMENT i
Secondary containment is designed to minimize any ground level release of f
l
-radioactive material which may result from an accident. The Reactor Enclosure l
l and-associated structures provide secondary containment during normal operation when the drywell is sealed and in service. At other times the drywell may be i
opIn and, when required, secondary containment integrity is specified.
i Establishing and maintaining a vacuum in the reactor enclosure secondary containment with the standby gas treatment system once per 24 months, along with t
tha surveillance of the doors, hatches, dampers and valves, is adequate to ensure j
that there are no violations of the integrity of the secondary containment.
l The OPERABILITY of the reactor enclosure recirculation system and the standby gas treatment systems ensures that sufficient iodine removal capability will j
be available in the event of a LOCA or refueling accident (SGTS only). The i
reduction in containment iodine inventory reduces the resulting SITE BOUNDARY radiation doses associated with containment leakage. The operation of this system and resultant iodine removal capacity are consistent with the assu.nptions t
used in the LOCA and refueling accident analyses.
Provisions have been made to continuously purge the filter plenums with instrument air when the filters are l
not in use to prevent buildup of moisture on the adsorbers and the HEPA filters.
I Although the safety analyses assumes that the reactor enclosure secondary containment draw down time will take 930 seconds, these surveillance require-ments specify a draw down time of 916 seconds. This 14 second difference is due to the diesel generator starting and sequence loading delays which is not part of this surveillance requirement.
1 The reactor enc;osure secondary containment draw down time analyses assumes a starting point of 0..:5 inch of vacuum water gauge and worst case SGTS dirty filter flow rate of 2800 cfm. The surveillance requirements satisfy this as-sumption by starting the drawdown from ambient conditions and connecting the adjacent reactor enclosure and refueling area to the SGTS to split the exhaust
. flow between the three zones and verifying a minimum flow rate of 2800 cfm from the test zone. This simulates the worst case flow alignment and verifies ade-quate flow is available to drawdown the test zone within the required time.
The Technical Specification Surveillance Requirement 4.6.5.3.b.3 is intended to be a multi-zone air balance verification without isolating any test zone.
The SGTS is common to Unit I and 2 and consists of two independent subsystems. The power supplies for the common portions of the subsystems are from Unit I safeguard busses, therefore the inoperability of these Unit 1 i
supplies are addressed in the SGTS ACTION statements in order to ensure adequate onsite power sources to SGTS for its Unit 2 function during a loss of offsite power event. The allowable out of service times are consistent with those in
.the Unit 1 Technical Specifications for SGTS and AC electrical power supply out of service condition combinations.
l t
I LIMERICK - UNIT 2 B 3/4 6-5 Amendment No. 37/, W, 86 l
l
y.
4
- CONTAllMENT SYSTEMS i BASES SECONDARY CONTAINMENT (Continued)
The SGTS fans are sized for three zones and therefore, when aligned to a single zone or two zones, will have excess capacity to more quickly drawdown the affected zones. There is ro maximum flow limit to individual zones or pairs of zones and the air balance and drawdown time are verified when all three zones are-connected to the SGTS.
The three zone air balance verification and drawdown test will be done after any major system alteration, which is any modification which will have 1
i an effect on the SGTS flowrate such that the ability of the SGTS to drawdown the reactor enclosure to greater than or equal to 0.25 inch of vacuum water gage in less than or equal to 916 seconds could be affected.
l The field tests for bypass leakage across the SGTS charcoal adsorber and HEPA filter banks are performed at a flow rate of 5764 i 10% cfm. The laboratory analysis _ performed on the SGTS carbon samples will be tested at a velocity of 66 fpm based on the system residence time.
The SGTS filter train pressure drop is a function of air flow rate and filter conditions. Surveillance testing is performed using either the SGTS or drywell purge fans to provide operating convenience.
Each reactor enclosure secondary containment zone and refueling area secondary containment zone is tested independently to verify the design leak tightness. A design leak tightness of 2500 cfm or less for each reactor l
enclosure and 764 cfm or less for the refueling area at a 0.25 inch of vacuum water gage will ensure that containment integrity is maintained at an acceptable level if all zones are connected to the SGTS at the same time.
The Reactor Enclosure Secondary Containment Automatic Isolation Valves and Refueling Area Secondary Containment Automatic Isolation Valves can be found in the UFSAR.
The post-LOCA offsite dose analysis assumes a reactor enclosure secondary containment post-draw down leakage rate of 2500 cfm and certain post-accident l
X/Q values. While the post-accident X/Q values represent a statistical inter-pretation of historical meteorological data, the highest ground level wind speed which can be associated with these values is 7 mph (Pasquill-Gifford stability Class G for a ground level release).
Therefore, the surveillance requirement assures that the reactor enclosure secondary containment is verified under meteorological conditions consistent with the assumptions utilized in the design basis analysis.
Reactor Enclosure Secondary Containment leakage tests that are successfully performed at wind speeds in excess of 7 mph would also satisfy the leak rate surveillance requirements, since it shows compliance with more conservative test conditions.
LIMERICK - UNIT 2 B 3/4 6-6 Amendment No. 74, M, 86
_,