ML20212G161
| ML20212G161 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 09/22/1999 |
| From: | DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20212G159 | List: |
| References | |
| NUDOCS 9909290114 | |
| Download: ML20212G161 (9) | |
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ATTACHMENT A Beaver Valley Power Station, Unit No. 2 License Amendment Request No. 149 The following is a list of the affected pages:
Affected Page: 3/4 7-25 l
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l 9909290114 990522 PDR ADOCK 05000412 P PDR
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'NPF-73 PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)
- c. Visual Inanaction Accantance Critaria Visual inspections shall verify that: (1) the snubber has no visible indications of damage or impaired OPERASILITY, (2) attachments to the foundation or supporting structure are functional, and (3) fasteners for attachment of the snubber to the component and to the snubber anchorage are functional.
Snubbers which appear inoperable as a result of the visual inspections shall be classified as unacceptable and may be reclassified acceptable for the purpose of establishing the next visual inspection interval, provided thats (1) the cause of the rejection is clearly established and remedied for that particular snubber and for other snubbers irrespective of type that may be generically susceptible; or (2) the affected snubber is functionally tested in the as-found condition and determined OPERABLE per Specification 4.7.12.s or 4.7.12.f, as applicable.
All snubbers found connected to an inoperable common hydraulic fluid reservoir shall be counted as unacceptable for determining the next inspection interval. A review and evaluation shall be performed and documented to justify continued operation with an unacceptable snubber. If continued operation cannot be justified, the snubber shall be declared inoperable and the ACTION requirements shall be met. !
j snubbers which have been determined to be inoperable as a result '
of unexpected transients, isolated damage, or other randon . ,
events, and cannot be proven operable by functional testing for l the same reasons, shall not be counted in determining the next i visual inspection period when the provision in 4.7.12.d (thatl failures are subject to an engineering evaluation of component structural integrity) has been met and equipment has been restored to an operable state via repair and/or replacement as necessary. i
- d. Functional Tanta O l At least once per 18 months during shutdown, a representative sample (of at least 104) of the total of each type of snubber its use in the plant shall be functionally tested either in place or in a bench test. For Functional Testing type of snubber shall mean a group or combination of groups by load size and kind (i.e., hydraulic or sechanical) or any other combination of load size and kind. For each snubber that does not meet the functional test acceptance criteria of specification 4.7.12.e or 4.7.12.f, an additional lot shall be functionally tested.
N A one-Iime 2>/denSion cRhe Snubbg,r forc.k.ictdiest frequent 3 for Opegg_k C3 cle, B is perrn&d . This e.densen is apphe ble, untH the fiMt entcg M6DE tekithever4 facumgrefuet.ing is ex her, outag e, 2. ROB er devember 30,20CO j BEAVER VALLEY - UNIT 2 3/4 7-25 Amendment No. 49
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ATTACHMENT B l l
( Beaver Valley Power Station, Unit No. 2 l .
License Amendment Request No. 149 l l
SNUBBER SURVEILLANCE EXTENSION j l
l A. DESCRIPTION OF AMENDMENT REQUEST l
The proposed Amendment affects Technical Specification (TS) i 3/4.7.12, " Snubbers." The requested change would revise the !
frequency of snubber functional tests specified in Surveillance 4.7.12.d to allow a one-time extension of the surveillance interval during Operating Cycle 8. The proposed extension would allow the required snubber testing to be performed during refueling outage 2R08, currently planned to begin September 30, 2000. Surveillance Requirement (SR) 4.7.12.d requires that, at least once per 18 months during shutdown, a representative sample (of at least 10%) of the total of each type of snubber in use in the plant shall be functionally tested either in place or in a bench test. The current surveillance interval of CD 4.7.12.d expires May 17, 2000, for the first group of snubbers due to be tested. This expiration date includes the 25% extension provided by Specification 4.0.2. Therefore, an additional plant shutdown would be required to meet the current surveillance interval. The performance of this surveillance normally takes several weeks and requires the coordination of vendor support onsite. The proposed change would provide a one-time extension of the current surveillance interval that would be limited to the end of 2R08 (first entry into Mode 4 after the outage) or November 30, 2000, whichever comes first. The November 30, 2000 date was selected to accommodate delays in the start of refueling outage 2R08 and still allow sufficient time to perform the required testing. The proposed change would allow testing to be performed during the next scheduled refueling outage and avoid an additional plant shutdown that would otherwise be required solely to perform this surveillance.
B. DESIGN BASES Snubbers are passive devices used for restraints for piping and components. Snubbers are required operable to ensure that the structural integrity of the reactor coolant system and other safety-related systems is maintained during and following a seismic or other similar event initiating dynamic loads. Visual inspections, functional tests, and service life monitoring verify snubber operability. TS 3/4.7.12 specifies test and inspection requirements in addition to the Inse.; vice Inspection and Test requirements required by Specification 4.0.5. The functional testing specified in TS 3/4.7.12 requires that at least every 18 l months during chutdown, a representative sample (of at least 10%)
of the total of each type of snubber in use in the plant shall be functionally tested either in place or in a bench test. TS 3/4.7.12 includes requirements that the representative sample
! selected for functional testing shall include various configurations, operating environments, and range of size and
ATTACHMENT B, continuad
. License Amendment Request No. 149
..' P a g e 2 capacity' of snubbers. In addition, TS- 3/4.7.12 includes a requirement.to: increase.the. scope of testing (an additional 10%)
for each snubber' type for each snubber in that group that does not meet the functional' test acceptance criteria.
The total population'of snubbers subject to the' sample test plan is 210.. The selection of 2 10% from each type of snubber results in.'a total of.25 snubbers (divided into several groups-based on type)-tested'during each surveillance interval.
'C . . JUSTIFICATION-This . Amendment : request is necessary due to the extended outage (approximately 9 months) that occurred in 1998. The extended outage'in 1998 resulted.in the start time for the Unit 2 eighth refueling outage (2R08) being delayed. The rescheduling of 2R08 has: placed the outage's start date beyond the current surveillance interval for snubber functional testing. The 2R08 refueling outage is currently planned to begin on September 30, 2000. . The current surveillance interval of SR 4.7.12.d expires May 17, 2000, for the first group of snubbers due to be tested.
The itest intervals for the remaining test groups all expire by June 11, 2000.. These expiration dates include the 25% extension provided by Specification 4.0.2. The proposed change would extend the surveillance interval for all test groups (total of 25 snubbers) until the end of refueling outage 2R08 (first entry into Mode 4 after 'the outage) or November 30, 2000, whichever comes first. The proposed change would result in a maximum surveillance interval extension of approximately 6.5 months for the first group of snubbers due.for testing (May 17 to November
.30).
Based on the previous test date (July 2, 1998) of the first group of snubbers due for functional testing, the calendar time from the start of the surveillance interval (July 2, 1998) to the
-beginning of 2R08-(currently planned to begin September 30, 2000) is'approximately 27 months. However, actual plant operating time during this period will be significantly less. Following the extended outage.in 1998, Unit 2 returned to power operation on September 29, 1998,.'and ran for 150 days until it came down for its seventh refueling outage on February 26, 1999. After a 44-day outage, Unit 2 began power operation on April 12, 1999, and ran for 97 days until a forced outage on July 18, 1999. After 9 days, . Unit 2 returned to its current service run on July 27, 1999. Therefore, from September 29, 1998, to July 27, 1999, Unit 2 operated for 247 days, or approximately 8 months. The time remaining from July 27, 1999, until the currently planned start'of 2R08 (September 30, 2000) is approximately 14 months.
Based'on-the currently scheduled start of 2R08, Unit 2 will have a predicted maximum operating time of approximately 22 months.
f' The elevated temperatures and vibration experienced during plant l operation are the primary contributors to snubber wear. The predicted operating time described above still falls within the B-2
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ATTACHMENT B, continu;d LicCnno A3:ndm:nt R:qusot No. 149 Page 3 22.5 month (18 month plus 25% extension) surveillance interval allowed for snubber functional testing. Thus, even with the requested extension, the Unit 2 snubbers are predicted to experience wear due to plant operating conditions (vibration and elevated temperatures) that is within the opera:Ing time allowed for ' by the TS surveillance interval of 22.5 months. However, given the November 30, 2000 deadline for extending the surveillance interval, the maximum time plant operation could continue before the surveillance was required to be performed would still be limited to approximately 24 months. Given that the operating time could only be extended approximately 1.5 months beyond the allowed 22.5 months, and the additional justifications discussed below, this potential extension of plant operating time is not expected to significantly contribute to snubber wear or degradation during the current operating cycle.
In addition, snubber-testing experience has shown that the historical failure rate of snubbers is low. There have been seven refueling outages since Unit 2's startup in 1987. Only during the first refueling outage, 2R01, did the snubber functional test sample plan identify any inoperable snubbers. In that outage, seven snubbers tested inoperable. All failed due to damage sustained during original construction and startup activities. Since ' 2R01, no inoperable snubbers were found by sample plan functional testing performed during each required surveillance interval. Also, the latest visual inspections performed on the Unit 2 snubbers during 2R07 (February 26, 1999 -
April 12, 1999) revealed no evidence of damage or potential problems with any snubber.
Therefore, based on the following:
- 1) The successful past performance of snubber functional testing and the latest visual inspections,
- 2) The plant operating time between surveillance performances continues to be limited, thus limiting the exposure to elevated temperatures and vibrations associated with plant operation, and
- 3) The fact that no dynamic or seismic event that could have challenged snubber operability has occurred to date during the current operating cycle.
There is a high level of confidence that no adverse effects on the operability of the snubbers, or the systems or components supported by those snubbers, will occur as a result of the requested extension. Based on the justifications discussed above, a one-time extension of the current surveillance test interval until the 2R08 outage should not result in the degradation of the capability of the snubbers to operate within their design requirements.
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I ATTACHMENT B, continu::d LicCnca Amendment Request No. 149 i
Page 4 I
l D. SAFETY ANALYSIS Snubbers perform a safety-related function as restraints for safety system piping and components. Although snubbers are normally passive devices, snubbers are required operable to ensure that the structural integrity of the reactor coolart j system and other safety-related systems are maintained during and l following a seismic or other similar event initiating dynamic loads. Visual inspections, functional tests, and service life monitoring are utilized to verify snubber operability. The requested change proposes a one-time extension of the current surveillance interval for functional testing of the snubbers !
until the 2R08 outage.
Based on the factors previously discussed regarding the operating history of snubber testing, the limited plant operating time during the current cycle, and the fact that no dynamic or seismic j event capable of challenging snubber operability has occurred during the current operating cycle, the proposed surveillance i extension will not: 1) affect the accident analyses, 2) impact the safety of the plant, or 3) reduce the margin of safety l derived from the snubber TS.
Therefore, this license amendment request will not adversely affect the safety of the plant. l E. NO SIGNIFICANT HAZARDS EVALUATION The no significant hazard considerations involved with the proposed amendment have been evaluated. The evaluation focused on the three standards set forth in 10 CFR 50.92(c), as quoted below:
The Commission may make a final determination, pursuant to the procedures in paragraph 50.91, that a proposed amendment to an operating license for a facility licensed under paragraph 50.21(b) or paragraph 50.22 or for a testing facility involves no significant hazards consideration, if operation of the facility in accordance with the proposed amendment would not:
(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or dif f erent kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
The following evaluation is provided for the no signi.#icant hazards consideration standards.
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- sATTACHMENT B, continuzd' s .. Licsnca'Am
- ndacnt R quoct No. 149,
,' Page 5' p
- 1. Does the change -involve a' significant . increase in the probability' or consequences.'of an accident previously evaluated?
.The proposed ~ change is :for a one-time extension to the
- surveillance -interval for . functional- testing of snubbers specified in Technical- Specification (TS) 4.7.12.d. The ,
-proposed change involves revising the calendar timefallowed.
between functional tests and would result in a maximum surveillance interval extension of.approximately 6.5 months.
Thel proposed thange continues to adequately limit plant
.v operation between required snubber surveillances by ensuring the required surveillances are performed by November 30,
.2000. Therefore, the proposed change continues to limit snubber wear due to vibration and elevated temperatures.
The elevated . temperatures' and vibration experienced during plant operation are the primary contributors to snubber wear. .
In addition, snubber-testing experience has shown that the
~ historical failure rate of snubbers is low. There have been seven ~ refueling ' outages since Unit 2's startup in 1987.
Only.' during .the first refueling outage, 2R01, did the snubber functional test sample plan identify any. inoperable
-snubbers.- In that outage, seven snubbers tested inoperable.
All' failed due to damage sustained during original construction- and startup activities. Since 2R01, no inoperable snubbers were found by sample plan functional testing performed during each surveillance interval. Also, the latest. visual inspections performed on the Unit 2 anubbers (during 2R07) revealed no evidence of damage or potential problems with any snubber.
Due to the low incidence of snubber functional test failures resulting from sample plan ~ testing and the limited plant operating time between tests, the possibility of a snubber failure resulting from this one-time surveillance extension is _ low. No changes are being made to any accident l initiator. No-analyzed accident scenario is being changed.
l The initiating conditions and assumptions of previously analyzed accidents remain unchanged. Therefore, the proposed change does not involve a significant increase in the probability of a previously evaluated accident. i l This change does not involve a physical change to the plant ]
l and does not affect the acceptance criteria specified in the i TS for snubber functional testing, nor does this change j reduce the remedial actions required for inoperable i snubbers. Therefore, the proposed change does not involve a l significant increase in the consequences of an accident previously evaluated.
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ATTACHMENT.B, continu d '
LicOnCo Am:ndmOnt R:qusct No. 149 .
Page 6 j
- 2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?
The proposed amendment does not involve any physical changes to the plant or the modes of plant operation defined in Appendix A of the operating license. The proposed amendment does not involve the addition or modification of plant equipment nor does it alter the design or operation of any plant systems. The one-time surveillance interval extension proposed by this change will not reduce the capability of the snubbers to perform their design function.
Therefore, operation of the facility in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Does the change involve a significant reduction in a margin of safety?
The margin of safety depends on the maintenance of specific operating parameters and systems within design requirements l and safety analysis assumptions.
The proposed amendment does not involve revisions to any safety limits or safety system setting that would adversely impact plant safety. The proposed amendment does not affect the ability of systems, structures or components important to the mitigation and control of design bases accident conditions within the facility.. In addition, the proposed amendment does not affect the ability of safety systems to ensure that the facility can be maintained in a shutdown or refueling condition for extended periods of time, and sufficient instrumentation and control capability is available for monitoring and maintaining the unit status.
The proposed change is for a one-time extension to the surveillance interval for functional testing of snubbers specified in Technical Specification 4.7.12.d. The proposed change continues to adequately limit plant operation between required snubber surveillances by ensuring the required surveillances are performed by November 30, 2000.
Therefore, the proposed change continues to limit snubber wear due to vibration and elevated temperatures. The elevated temperatures and vibration experienced during plant operation are the primary contributors to snubber wear.
In addition, snubber-testing experience has shown that the historical failure rate of snubbers is low. There have been seven refueling outages since Unit 2's startup in 1987.
only during the first refueling outage, 2R01, did the i
snubber functional test sample plan identify any inoperable snubbers. In that outage, seven snubbers tested inoperable.
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l MATTACHMENT B,'continusd'
. License Amendment Request No. 149 Page 7
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1 All failed due to damage sustained during original construction and startup activities. Since 2R01, no l inoperable snubbers were found by sample plan functional i testing performed during each surveillance interval. Also, the latest visual inspections performed on the Unit 2 snubbers' (during 2R07) revealed no evidence of damage or potential problems with any snubber.
This change does not involve a physical change to the plant and does not affect the acceptance criteria specified in the TS for snubber functional testing, nor does this change reduce the remedial actions required for inoperable snubbers. . The snubbers and systems supported by the snubbers will continue to be available to perform their intended safety functions during the requested extension period.
Therefore, operation of the facility in accordance with the proposed amendment will not involve a significant reduction in a margin of safety. j F. NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION Based on the considerations expressed above, it is concluded that the' activities associated with this license amendment request satisfy the requirements of 10 CFR 50.92(c) and, accordingly, a no.significant hazards consideration finding is justified.
G. ENVIRONMENTAL CONSIDERATION This license amendment request changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. It has been 1 determined that this licanse amendment request involves no significant increase in the amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative ,
occupctional radiation exposure. This license amendment request
-may change requirements with respect to installation or use of a facility component located within the restricted area or change an inspection or surveillance requirement; however, the category of this licensing action does not individually or cumulatively have a significant effect on the human environment. Accordingly, l this license amendment request meets the eligibility criteria for I
categorical ~ exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this license amendment request.
I H. UFSAR CHANGES None.
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