ML20116E192
| ML20116E192 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 07/25/1996 |
| From: | Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9608050136 | |
| Download: ML20116E192 (13) | |
Text
I 1
Station Srpport Department e
A 10CFR50.55a(g)(5)(lii)
PECO NUCLEAR recoee c - eev Nuclear Group Headquarters A Uwr (* PECO ENrRGy 965 Chesterbrook Boulevard Wayne, PA 190875691 July 25,1996 Docket Nos. 50-352 50-353 License Nos. NPF-39 NPF-85 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Umerick Generating Station, Units 1 and 2 Relief Request Revisions for the First Ten Year Interval Pump and Valve Inservice Testing Program Gentlemen:
Enclosed are proposed revisions to five (5) relief requests for the Umerick Generating Station (LGS), Units 1 and 2, First Ten Year Interval Pump and Valve Inservice Testing (IST) Program.
These proposed IST relief request revisions request relief from the requirements of Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code concerning leak rate testing and exercise testing of valves installed in various systems at LGS, Units 1 and 2. These revisions to the relief requests are necessary in order to support the implementation of a Technical Specifications (TS) change request (i.e., TS Change Request No.
95-14-0) submitted to the NRC by letter dated June 28,1996, requesting approval to adopt the performance based 10CFR50, Appendix J, Option B, requirements at LGS, Units 1 and 2. The following relief request revisions are enclosed.
Relief Request No. GVRR-1, Revision 2, Containment Isolation Valve Leak Rate Testing.
Relief Request No. 41-VRR 1, Revision 1, Exercise Testing of Feedwater System Primary Containment isolation Valves.
Relief Request No. 43-VRR-1, Revision 1, Exercise Testing of Recirculation Pump Seal Purge Primary Containment isolation Valves.
Relief Request No. 48-VRR-1, Revision 1, Exercise Testing of Standby Liquid Contr.:A System Primary Containment isolation and injection Valves.
Relief Request No. 52 VRR-1, Revision 2, Exercise Testing of Containment l
Isolation and Pressure isolation Function of Core Spray System injection Check l
Valve.
j 050026 jy/7',
9608050136 960725 PDR ADOCK 05000352 P
PDR l
July 25,1996 Page 2 As a result of processing TS Change Request No. 95-14-0 for LGS, Units 1 and 2, we determined that it was necessary to revise the relief requests identified above. Therefore, we are submitting these revised relief requests to facultate implementation of TS Change Request No.95-144. The detaHs and justification for relief are provided in the enclosed relief requests. We would appreciate if the NRC would review the enclosed relief request revisions, and grant the requested relief by January 1,1997, in order to support the implementation schedule for TS Change Request No. 9514-0.
If you have arr/ questions or require additional information, please do not hesiiate to contact us.
j l
Very truly yours,
.h.
G. A. Hunger, Jr.
l Director - Licensing Enclosures cc:
T. T. Martin, Administrator, USNRC, Region I (w/ attachment)
N. S. Perry, USNRC Senior Resident Inspector, LGS (w/ attachmeny i
i l
l 4
l I
a
1
\\
i i
\\
i i
l i
)
i Limerick Generating Station Units 1 and 2 First Ten-Year Interval
{
inservice Testing Program i
j RELIEF REQUEST NO. GVRR-1, Revision 2
}
1 4
1 4
1 l
LGS 1 & 2, IST Program Docket Nos. 50-352/50-353 Page 1 of 2 RELIEF REQUEST NO. GVRR-1, REVISION 2 l
Valves:
Containment isolation Valves i
Category:
A i
Testing Requirement (a):
Leak rate test in accordance with subsection IWV-3420.
i Basis for Relief:
Containment isolation valves are required to be leakage rate tested in accordance with 10CFR50, Appendix J. The leakage rate requirement is based on a total allowable leakage rate for all valves instead of an individual valve leakage rate. IWV-2100(a) defines Category A as, " valves for which seat leakage is limited to a specified maximum i
amount in the closed position of fulfillment of their function." Although for containment isolation valves leakage rates are not limited on an individual basis by Appendix J, they 4
have been determir.ed to be Category A valves.
Since containment isolation valves are Category A, the leakage rate testing 3
requirements of IWV-3420 must be satisfied. The leakage rate testing performed per Appendix J satisfies the requirements of IWV-3421 through 3425, however, it does not satisfy the individual valve leakage rate analysis and corrective actions of IWV-3426 and IWV-3427.
Appendix J testing is accomplished by performing individual local leak rate tests on each containment penetration. The results of these tests represent the total leakage from the boundary valves associated with the penetration. The maximum permissible leakage is determined by one of two methods.
.i
- 1) In order to prevent duplicate leakage testing for penetrations with multiple valves of relatively similar nominal size, a maximum permissible leakage will be established for
}
each individual local leak rate test based on the smallest valve in the group, if this value is exceeded, then corrective action will be taken to restore the leakage rate to within acceptable limits. The proposed actions will be taken in lieu of IWV-3426 and IWV-i 3427(a). Double frequency testing, as required by IWV-3427(b), shall not be performed.
The usefulness of the data does not justify the burden of complying with this requirement. Corrective action previously addressed will be sufficient in maintaining acceptable leakage rates.
- 2) Several penetrations (23) are associated with valves of relatively significant different nominal sizes (i.e. 24-inch valve,1.5-inch valve, and a 1-inch valve) that are tested in
?
parallel. Because of the large difference in valve size, it is not practicable to assign a maximum valve group leak rate that is low enough to detect significant leakage from a 1 inch valve, and high enough to allow acceptable leakage from the 24-inch valve.
Assigning a maximum value based on the smallest valve would result in unnecessary maintenance being performed due to acceptable leakage through the larger valve.
j Therefore, a maximum allowable leak rate based on the summation of the individual valve leak rates is established.
f j
l LGS 1 & 2, IST Program Docket Nos.50-353/50-363 Page 2 of 2
{
RELIEF REQUEST NO. GVRR-1, REVISION 2 (cont'd) i t
i The leak rates are determined using ASME Section XI Code requirements. Additionally, 3
an " alert" limit has been established based on previous valve group test results. This
" alert" limit is used for comparing current test data with previous test results. In addition, the " alert" value is used to trend the leak tight performance of the valve group.
Of the 23 valve groups identified,14 have sufficient test taps available to perform visual leakage inspections which can be used for detecting leakage through the smaller valves in the group. This visual inspection is performed when leak rates exceed the " alert" limit even though the total leak rate may be less than the maximum allowed for the group.
For the remaining 9 groups where test taps ara not available, a conservative combined leak rate is used to assess the leak tight integrity of the valves in the group. If the leak 4
l rates exceed the specified " alert" limit, corrective actions are implemented.
l The method used to established the maximum allowable leak rate for each valve, and
)
subsequently the valve group, is based on the ASME Section XI, Paragraph IWV-3426 criteria. Although individual valve leak rates are not being measured, this method meets the intent of the Code since the leakage value is quantified and corrective action is taken if the total leakage for the group exceeds the maximum allowed for the group.
1 Alternate Testing:
)
Containment isolation valves will be leak rate tested in accordance with the 10CFR50 Appendix J Option B Type C testing program. The frequency will be as defined in the Primary Containment Leakage Rate Testing Program. In addition, a maximum j
permissible leakage criterion will be established for each individual local leak rate test. If the local leak rate test leakage criterion is exceeded, corrective action will be taken to restore the leakage rate to within the acceptable value.
=
j l
l 1
l l
l l
l Limerick Generating Station Units 1 and 2 i
First Ten-Year Interval inservice Testing Program RELIEF REQUEST NO. 41-VRR-1, Revision 1 l
l l
l 1
l l
l l
LGS 1 & 2,IST Program Docket Nos. 50-353/50-353 Page 1 of 1 i
l RELIEF REQUEST NO. 41-VRR-1, REVISION 1 l
System:
Nuclear Boiler Valve (s):
41 IF010A, B 41-2F010A, B l
Category:
A, C Function:
Feedwater system inside primary containment isolation valve Testing Requirement (s):
Exercise in the reverse direction.
Basis for Relief:
i Verificaticn of reverse flow closure of these valves is accomplished by leak testing.
)
i Since these valves are containment isolation valves, they are leak tested during
)
i Appendix J, Option B Type C testing at refueling. In order to perform leak testing manual valves located inside primary containment must be opened and temporary test equipment installed. During power operation and norma:ly at cold shutdown, the primary
]
containment atmosphere is inerted with nitrogen, limiting access to emergencies only.
Because leak testing at power is not possible, and is impractical at cold shutdown due to j
the probability of delaying plant start-up, these valves will be leak tested at refueling.
l Alternate Testing:
Reverse flow closure will be verified during Appendix J Option B Type C testing during j
refueling.
i I
i t
Umerick Generating Station Units 1 and 2 First Ten-Year interval Inservice Testing Program RELIEF REQUEST NO. 43-VRR-1, Revision 1 1
LGS 1 & 2, IST Program Docket Nos. 50-352/60-353 Page 1 of 1 RELIEF REQUEST NO. 43-VRR-1, REVISION 1 l
System:
Reactor Recirculation Pump System Valve (s):
43-1004A,B 43-2004A,B Category:
A, C Function:
Recirculation pump seal purge primary containment isolation valve.
Testing Requirements:
Exercise in the reverse direction.
j Basis for Relief:
These check valves are located inside primary containment in the reactor recirculation pump seal purge supply lines and are open during power operation. Exercising the valves to the closed position during operation would require interruption of seal purge water flow to the reactor recirculation pumps. Due to system configuration the most practical method to verify reverse flow closure of these valves is by leak testing. In order to leak test the valves, manual valves located inside the primary containment must be opened. During power operation and cold shutdown, the containment atmosphere is j
normally inerted with nitrogen, limiting access to emergencies only. Leak testing at power is not possible and is impractical at cold shutdown, when containment is de-Inerted, by possibly delaying plant start-up. These valves will be tested in the reverse direction at refueling during Appendix J Option B Type C testing.
Alternate Testing:
Reverse exercising will be verified during Appendix J, Option B Type C testing during refueling.
i
)
r I
I j
1 1
i i
1 i
l i
l l
l Limerick Generating Station Units 1 and 2 1
First Ten-Year Interval inservice Testing Program i
1 i
RELIEF REQUEST NO. 48-VRR-1, Revision 1
]
l l
l i
I i
I e
l
m _ _ _. _ _
_m LGS 1 & 2, IST Program Docket Nos. 50-352/50-363 Page 1 of 1 RELIEF REQUEST NO. 48-VRR 1, REVISION 1 l
System:
Valve (s):
HV-4 8-IF006A,B HV-48-2F006A,B 48-IF007 48-2F007 48-1027 48-2027 Category:
A, C [HV-48-1(2)F006A,B and 48-1(2)F007]
[48-1(2)027]
Function:
SLC inboard and outboard injection check; primary containment isolation [HV 1(2)F006A,B and 48-1(2)F007).
SLC inboard injection check [48-1(2)027].
l Testing Requiremer ts:
Exercise in the forward direction stop check valves [HV-48-1(2)F006A,B] and check i
valves [481(2)027].
Exercise in the forward and reverse direction check valves (48-1(2)F0071).
Basis for Relief:
Verifying forward flow operability requires firing a squib valve and injecting water into the Reactor Coolant System using the standby liquid control pumps. The frequent introduction of relatively colder water into the Reactor Coolant System, associated with this type of testing, would result in an excessive number of thermal cycles to SLC piping and components. Additionally, the introduction of colder water would increase reactivity due to the colder moderator temperature.
Since the firing of a squib valve requires valve disassembly to replace intemats, firing should be minimized. Therefore, forward flow testing of the check valves will be performed during SLC injection testing as required by Technical Specifications 4.1.5.d.l.
Due to system configuration the most practical method to verify reverse flow closure on 48-1(2)F007 is by leak testing. In order to leak test, temporary test equipment must be installed inside primary containment. During power operation and normally at cold shutdown, the primary containment atmosphere is inerted with nitrogen, limiting access to emergencies only. Because leak testing at power is not possible, and is impractical at cold shutdown, by possibly delaying plant start-up, this valve will be tested in the reverse direction at refueling during Appendix J, Option B, Type C testing.
Alternate Testing:
Forward flow operability will be verified at refueling during SLC injection testing.
Reverse flow closure for 48-1(2)F007 will be verified at refueling during Appendix J, Optic n B, Type C testing.
l l
l 1
I i
l l
Limerick Generating Station i
Units 1 and 2 i
First Ten-Year interval l
Inservice Testing Program RELIEF REQUEST NO. 52-VRR-1, Revision 2 I
l i
1 l
l 1
l I
i
f;.
I LGS 1 & 2,IST Program Docket Nos. 50-352/50-353 f
Page 1 of 1 RELIEF REQUEST NO. 52-VRR-1, REVISION 2 l
System:
Core Spray Valve (s):
HV-52-108 HV-52-208 Category:
A, C l
Function:
Core spray injection check valve; containment isolation and pressure isolation function.
i Testing Requirements:
Exercise in the forward and reverse direction.
Basis for Relief:
The above valves are equipped with air actuators that are designed to provide spring i
assistance for valve closure only. Therefore, flow exercising in the forward direction can only be accomplished by injection into the vessel. Injection into the vessel using the core spray pump is not possible because the core spray pump is not capable of
)
overcoming reactor pressure during normal operation. The HPCI system injects through J
this valve; however, this would require the injection of relatively cold water from the condensate storage tank into the reactor vessel via the HPCI pump. The introduction of
{
relatively colder water into the Reactor Coolant System would result in an excessive number of thermal cycles to system piping and components. Additionally, the j
introduction of colder water would increase reactivity due to the colder moderator temperature. Therefore, as an altemate means of forward exercising, the valve will be i
manually full opened in accordance with IWV-3522(b).
Manually forward exercising this valve at cold shutdown requires equalizing pressure l
across the valve. Pressure equalization across this valve would be accomplished by injection of condensato into the vessel through a stagnated leg of the core spray system.
l Use of this injection path would introduce crud into the reactor vessel and could impact unit restart due to Technical Specification 3/4.4.4 chemistry requirements. A means of crud removal is not available because no vent or drain path exists on this leg of piping.
Crud removal from this leg of piping can only be performed during refuel by flushing the core spray header into the reactor using station procedures. The reactor water cleanup system would have to be placed into operation to reduce crud levels so the chemistry j
levels would be within acceptable ranges. Restart would be delayed by this cleanup process.
4 i
Additionally, manually forward exercising requires partial disassembly of the actuator, which if attempted during cold shutdown, could result in a delayed plant start-up.
Therefore, forward exercising will be accomplished at refueling and exercising in the reverse direction will be accomplished during Appendix J Option B and Section XI leak rate testing.
Alternate Testing:
Manually exercising in the forward direction will be performed at refueling. The force used to forward stroke these valves will not exceed the criteria specified in IWV-3522(b).
Reverse flow closure will be verified at refueling by Appendix J Option B and Section XI leak rate testing.
1
!