ML20199G770

Application for Amends to Licenses NPF-39 & NPF-89,removing Maximum Isolation Time for HPCI Turbine Exhaust Containment Isolation Valve HV-055-1(2)F072 from Ts.Change Request 98-01-0 & marked-up TS Encl

ML20199G770
Person / Time
Site:	Limerick
Issue date:	01/27/1998
From:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20199G774	List: ML20199G770 ML20199G777
References
NUDOCS 9802040342
Download: ML20199G770 (9)

Text

l Station Support Department A 10 CFR 50.90 v --

PECO NUCLEAR nw -u c-A Unit of PECO Energy NvNItNsYe January 27, 1998 Docket Nes. 50-352 50-353 License Nos. NPF-39 i NPF-85 U.S. Nuclear Regulatory Comission ATTN: Document Control Desk Washington, DC 20555

Subject:

Limerick Generating Station, Units 1 and 2 Technical Specifications Change Request No. 98-01-0 Deletion of HPCI Turbine Exhaust Valve Isolation Time from Technical Specifications

Dear NRC Officials:

PECO Energy Company is submitting Technical Specifications (TS) Change Request No. 98-0.-0, in accordance with 10 CFR 50.90, requesting a change to TS (i.e., Appendix A) of operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2.

The proposed changes will remove the maximum isolation time for the High Pressure Coolant Injection (HPCI) Turbine Exhaust Containment Isolation Valve "HV-055-1(2)F072" from TS.

Information supporting this TS Change Request is contained in Attachment I to this letter, and copies of the " marked-up" Technical Specifica- I tions pages are contained.in Attachment 2. This information is being ii submitted under affirmation, and the required affidavit is enclosed.

We request that, if approved, the changes be issued as soon as possible, , i}

and become effective within 30 days of issuance.

a 0 C'7 IllIllI$l}l\ \\l)\ll)l[

9902040342 990127 PDR ADOCK 05000352

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. January .27,- 1997.-

.Page 2 k

If you have any questions, please do not hesitate to contact us.

Very truly-yours,

b. AA,f ,

G. A. Hunger, r.

Director - Licensing Attachments

- Enclosure cc: H. J. Miller,' Administrator, Region I, USNRC (w/ Attachments, Enclosure).

A. L. Burritt, USNRC Senior Resident Inspector, LGS R. R. Janati, PA Bureau of Radiation Protection " "

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COMMONWEALTH OF PENNSYLVANIA  :

-ss COUNTY OF PHILADELPHIA  : i J.- B. . Cotton, being first duly sworn, deposes and says: That he is Vice President of PECO Energy Company, the Applicant-herein; that he has read the enclosed Technical Specifications Change Request No. 98-01-0 " Deletion of HPCI Turbine Exhaust Valve Isolation Time from Technical Specifications," for Limerick Generating Station, Ur.!', I and Unit 2, Facility Operating License Nos. NPF-39 and NPF-85, and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.

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/ Afice President Subscribed and sworn to before me this JM ' day o 1998.

d.kmu Notary public-wrARIAL stAL CAMOL A.WALTON NM M uvY urIeNy b ,

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- ATTACHMENT LIMERICK GENERATING STATION m,

UNITS 1 AND 2 DOCKET.NOS.

50-352

- 50-353 LICENSE NOS.

NPF-39 NPF-85

" Deletion of HPCI Turbine Exhaust Valve Isolation Time from Technical Specifications" Information Supporting Changes.- 5 Pages c-W

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DISCUSSION AND DESCRIPTION OF THE PROPOSED CHANGES

-PECO Energy Company (PECO Energy) is requesting-Limerick Generating Station (LGS) Technical Specifications (TS) changes which will revise TS Table 3.6.3-1

'Part A - Primary Containment Isolation valves,' by removing the numerical maximum stroke time for penetration 210 "HPCI Turbine Exhaust" and adding a notation that the isolation time is not required.

SAFETY ASSESSMENT The maximum isolation time for the HPCI Turbine Exhaust Valve is not a criteria for safety limits delineated in 10 CFR 50.36 ( c )(1) nor does it mect the criteria for Limiting Conditions for Operation delineated in 10CFR50.36 ( c )(2)(ii)(A thru D). In addition, NRC Generic Letter 91-08

" Removal of Component Lists From Technical Specificatior.s," states that "The removal of valve stroke times that are included in some plant TS would not-alter the TS requirement to verify that the valve stroke times are within their limits. Therefore, removal of these closure times is acceptable."

Removal of- specific maximum isolation times and closure stroke verification for remote manual isolation valves from TS is consistent with Improved Standard Technical Specifications (NUREG -1433, Rev.1). Improved Standard TS generic Primary Containment _ Isolation Valve (PCIV) surveillance requirements are-limited to verifying isolation stroke times only for PCIVs receiving automatic isolation signals.

The subject valve: will continue to be included in the Inservice Test (IST)

Program (ML-008) and the Limerick Generic Letter 96-05 Motor Operated Valve (MOV)-Program and be subject to periodic verification testing involving-diagnostic testing. This testing will confirm the actuator and valve performance nargins established under the Generic Letter 89-10 MOV Program.

Complete failure of the valve to isolate has been evaluated to be of negligible safety significance. This conclusion is based on the established long term water seal associated with the penetration and the Seismic Category I design of the HPCI system. In addition, installed outboard check valve 055-

'1(2)f021-will function to prevent gross suppression pool leakage through the HPCI turbine exhaust line.

The following discussions describe the functions of valve HV-055-1(2)F072.

The -' design considerations and specific discussions were derived from the current Limerick Safety Analysis-Report (SAR) and the Limerick TS.

The High Pressure Coolant Injection (HPCI) Valve "HV-055-1(2)F072" is a -

12 inch, normally open valve- that provides remote manual isolation to containment penetration 210. The subject valve is a remote manual primary containmut isolation valve (PCIV) which is not required to respond to any analyzed accidents or transients.

Maximum isolatirn time for this valve is not a safety analysis limit associated with any DBA accident (LOCA/ LOOP), station blackout or-fire safe shutdown analysis. The maximum time established for this valve is based on standard valve design practices and is used to establish Inservice Test (IST) 1

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. Program _ performance' criteria.- The LGS IST program will still-maintain an=IST

. .. basis maximum time for HV-055-1(2)F072 to establish action and= alert levels-

for

valve performance monitoring.1These performance-based values, in -

l conjunction with diagnostic: test criteria, are used for motor operated valve (MOV)L eaterialicondition monitoring and trending. - Therefore, eliminating' the subject maximum isolation time requirement from TS will not increase--the-iprobability of-malfunction of the valve since the principal means of; monitoring valve _ performance remains unchanged.

Tliis: v^alv'e'is capable of- performing the remote manual function described-in

'the SAR. The remote manual isolation design is used where the penetration is water sealed long tere following an. accident and the system that the valve is isolating is a closed ioop safety system which is in service following an accident.1This' general design-is ' described in the LGS Updated Final Safety -

Analysis Report-(UFSAR)'Section 6.2.4.3.1.3.1. - Section 6.2.4.3.1.3.1.4 of_the UFSAR describes the isolation features of this-specific penetration. This-section also describes a checi valve 055-1(2)F021,- upstream of HV-055-

-1(2)F072 which functions to prevent gross suppression pool water leakage to the HPCI turbine eyhaust line. Given the assured 30' day water seal and design

' features of the HPCI system, containment leakage through this valve and:

1 associated penetration _is not associated with any accident or radiol.ogical_

' release' analysis. Since the exhaust lines are submerged beneath the minimum--

-Suppres , ton Pool water level and the HPCI system is a closed system outside Primary *ontainment, containment bypass-leakage is not a concern.

HV-055-1(2)f072 provides a' system design feature to isolate a potential containment leak path. As' described in LGS UFSAR Section 6.2.4.3.1.3.1, any leakage through this path will be monitored and contained in the HPCI pump room. This turbine exhaust line is classified as a moderate energy fluid-system per the criteria of UFSAR_ Section 3.6.1.2. Per LGS UFSAR Section 3.6.1.1, a crack in this. line-is the only- postulated event. Pipe breaks of the applicable piping are beyond design. bases. Leakage of this line can be remotely isolated from the control room if a pipe crack occurred during normal-plant operation. Manual isolation of HV-055-1(2)F072 occurs procedurally when HPCI is no longer._needed and when plant parameters indicate there-is leakage into the HPCI room. This valve would only be manually closed under events where there was a need to' isolate HPCI from suppression pool water inventory.

based on plant indications'which are entry conditions for LGS Special Event procedure SE 4-1 " Reactor Enclosure Flooding", LGS Transient Response

-Implementation Plan procedures T-250 ' Remote manual Primary Containment Isolations," or.T-260 " Reactor Vessel Venting." Each of these procedures may ultimately require isolation of the-HPCI turbine exhaust line by manually closing:HV-055-1(2)F072. - Given that these procedurally mandated valve

isolations are all via remote manual .means, valve isolation time is not-a -

Tcritical parameter requiring: specific acceptance criteria.

.Thit activiti ~doesLnot- affect'the ability'of the valve to isolate the leak or

( :to containia leak- M LGS UFSAR . Sections -6.2.4;3.1.3.1. and 6.2.4.3.1.3.1.C provide water seal penetration-general: design- and specific design details, respectively...These-sections;' describe that there are-multiple-barriers to the irelease of- suppression-pool water, and this valve provides_ one method to '

cisolate? potential leakage. 'As a result, the valve wil_1 function to isolate lany potential 1eak, - but=the failure of the valve is already analyzed by s-x< '

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i general plant design criteria. HV-055-1(2)F072 has no specific seat leakage

. integrity requirements as referenced in: TS Table 3.6.3-1 notation number 35 for Unit I and notation number 36 for Unit 2; IST Specification ML-008; and LGS UFSAR Table 6.2-17.

The suppression pool inventory is also important to safety. The integrity of the suppression pool water supply is ensured by the general plant design of water sealed penetrations both with and without successful isolation of this single remote manual isolation valve. The penetration is water sealed from the containment atmosphere and there is no driving force for a water leak without containment being pressurized. This is the expected condition under which LGS Special Event procedure SE 4-1 " Reactor Enclosure flooding" is entered.

Following an accident when HPCI is no longer needed, containment may be slightly pressurized to 10 psig or less (reference UFSAR Figure 6.2.-7),

causing suppression pool water to pre:s into the HPCI exhaust line. Check valve 055-1(2)f021 provides the normal and immediate leakage barrier as described in UFSAR Section 6.2.4.3.1.3.1.4. A gross release of suppression pool water is prevented by HV-055-1(2)F072, 055- 1(2)F021 check valve, an intact HPCI exhaust line, or ultimately by the containment of water within the HPCI room.

The LGS UFSAR Table 6.2-17 describes that the stroke time of this valve is nominal and not critical for High Energy Line Break (HELB), accident release, or Emergency Core Cooling System (ECCS) performance concerns. LGS UFSAR Section 6.2.4.2 indicates that valves having critical stroke times to limit accident releases, to ensure proper operation of ECCS systems or to mitigate a HELB event are annotated on this table. HV-055-1(2)F072 has no special annotatior.s, only reference to a standard stroke time.

Information Suonortina a Findina of No Sionificant Hazards Consideratios We have concluded that the proposed changes to the Limerick Generating Station, Unit 1 and Unit 2, Technical Specifications (TS) which will revise TS Table 3.6.3-1 and its natations, do not involve a Significant Hazards Consideration. In support of this determination, an avaluation of each of the three (3) standards set forth in 10 CFR 50.92 is provided below.

1. The orocosed Technical Sorcifications chanaes do not involve a sianificant increase in the probability or conseouences of an accident previously evaluated.

Changes to Technical Specifications regarding the removal of the High Pressure Coolant Injection (HPCI) Turbine Exhaust Valve maximum stroke times do not change the frequency or consequences of any accident previously evaluated.

The proposed changes do not change the function of the HPCI system nor any cafety. function of the valve as described in the SAR. The isolation stroke times are not limits upon important process variables that are found to be necessary to reasonably protect the integrity of certain of the physical barriers that guard against the uncontrolled release of radioactivity. The stroke times do not detect or indicate an abnormal degradation of the reactor coolant pressure boundary. The stroke times i

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are not a process variable, design feature, or operating restriction

.. . that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier. The stroke times are not part of a component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that "ither assumes the failure of or presents a challenge to the integrity of a fission product barrier. The stroke times are not a structure, system, or component which operating experience or probabilistic risk assessment has shown to be signtficant to public 1ealth and safety.

Therefore, the changes will not increase the probability or consequences of an accident previously evaluated.

2. The oronosed Technical Soecifications chanaes do not create the gossibility of a new or different kind of accident from any accident Dreviously evaluated.

The proposed Technical Specifications changes regarding the removal of the High Pressure Coolant Injection (HPCI) Turbine Exhaust Valve maximum stroke times do not affect the probability of a malfunction of equipment important to safety. Safety related HPCI system operation occurs with the subject valve passively open. This valve would only be manually closed under events where there was a need to isolate the HPCI system from the suppression pool. The manual closing of the valve may occur under these events and is controlled by station procedures. Given that these procedurally mandated valve isolations are all via remote manual means, valve isolation time is not a critical parameter requiring specific acceptance criteria.

The Inservice Testing (IST) Program will still maintain an IST program basis maximum stroke time for HV-055-1(2)f072 to establish action and alert levels for valve performance monitoring. These performance based values, in conjunction with diagnostic test criteria, are used for motor operated valve material condition monitoring and trending. Therefore, eliminating the subject maximum isolation time requirement from TS will not increase the probability of malfunction of the valve since the d

principal means of monitoring valve performance remains unchanged.

Therefore, these changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. The oroposed Technical Soecifications chanaes do not involve a sianificant reduction in a maroin of safety.

There is no defined margin of safety for remote manual valve isolation times discussed in Technical Specification Bases. In addition, the valve maximum stroke time will be retained in the IST program.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

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INFORMATION SUPPORTING AN ENVIRONMENTAL-ASSESSMENT ,

' An Environmental-Assessment is not required for the Technical Specifications changes proposed by this TS Change Request because the requested changes to the Limerick Generating Station, Unit 1.and Unit 2, TS e m form to the criteria for " actions eligible for categorical exclusion," as speo;fied in 10 CFR 51.22 (c) (9). The requested changes will have no impact on the environment. The proposed TS changes do not involve a Significant Hazards Consideration as discussed in the preceding safety assessment section. The-proposed changes do not involve a significant-change in the types or significant increase in the amounts of any effluent that may be released offsite, in addition, the proposed TS changes do not involve a significant increase in individual or cumulative occupational radiation exposure.

CONCLUSION The Plant Operations Review Committee ano the Nuclear Review 3 card have reviewed these proposed changes to the Limerick Generating Station, Unit I and

. Unit 2, Technical Specifications, and have concluded that they do not involve an unreviewed safety question, they do not involve a Significant Hazards ,

Consideration, and they will not endanger the health and safety of the public.

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