ML20087A426

Proposed TS 3/4.7.8 Re Snubber Visual Surveillance/Insp Requirements

ML20087A426
Person / Time
Site:	Waterford
Issue date:	01/06/1992
From:	ENTERGY OPERATIONS, INC.
To:
Shared Package
ML20087A420	List: ML20087A418 ML20087A426
References
NUDOCS 9201090111
Download: ML20087A426 (21)

Text

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PLANT SYSTEMS 3/4.7.8 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.8 All hydraulic and mechanical snubbers shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4 MODES 5 and 6 for snubbers located on systems required OPERABLE in those OPERATIONAL MODES.

ACTION:

With one or more snubbers inoperable on any system, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> replace or restore the inoperable snubber (s) to OPERABLE status and perform an engineering evaluation per Specification 4.7.8q. on the attached component or declare the

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attached system inoperable and follow the appropriate ACTION statement for that

. system.

_ SURVELLIANCE REQUIREMENTS 4.7.8 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

a. Inspection Types As used in this specification, type of snubber shall mean snubbers of the same design and manufacturer, irrespective of capacity.

b. Visual Inspections Snubbers are categorized as inaccessible or accessible during reactor

' operation. Each of these groups (inaccessible and accessible) may be inspected independently according to the schedule below. The first inservice visual inspection of each type of snubber shall be performed after 4 months

• but within 10 months of commencing POWER OPERATION and shall include all hydraulic and mechanical snubbers. If all snubbers of each type on any system are found OPERABLE ouring the first inservice visual inspection, the second inservice visual inspection of that system shall be performed at the first refueling outage. Otherwise, subsequent visual inspections of a given system shall be performed in accordance with the following schedule:

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COP'i NO. _ ., -

• Visual inspection of the inaccessible snubbers can be performed at the first available ~itage af ter 2 months of commencing Power Operation.

WATERFORD - UNIT 3 3/4 7-21 AMENDMENT NO. 2 noioro1i1 MOiu.t. .,

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PLANT SYSifMS SURVE]LL ANCE RQ!RfMErd75 (Contige,d) _ _ , , , _

Nc. of inoperab1 A Snubbtrs o ' Ecch fype Subsequent ViseC oli Any System per inspectior deriod

nspec;1on _ Perigd"#

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0 lJ months 27!,'

1 12 months 1 25%

2 6 months a 25%

3,4 124 days i 25%

5,6 , '/ 62 day; 1 25%

0 or a, ore $1 days 1 25%

c. VisuhlInspe:tionAceptanceCriterp J

Vist,al 1 ispections shall verify that: (1) t.here are no visible indications of dattagn or impaired OPERABILITY and (2) attachments to the foundation or supporting structure are f ecure, and (3) fasteners for attachment of the snubbar to the corponent arid to the snubber anchorage are secura. Snubbers which appear inuperablo as a eisult of visual inspections may be determined OPER/.Bl.E for the porpose of establishing the next visual inspection interval, provided that:

(1) the cause of ^.he rejection is clearly establish 1d and remedied Nr that porticular snubber And for other snubbers irrespective of type on tnr.t system that may be gewically suspectibic; and (2) the aP.'ected snubber it functionally tested in the as' found condition and detarmineri OPERABLE per Specif b ations 4.7.8f. All snubbers connected to an inoperable r.ommon hydraulic fivid reservoir t hall be counted as inoperable snubbtrs. For trise snubbers common to more then one system, the OPERABILITY of such snubbers si.all be considered in assessing the sarveillance schedule for each of the related systems,

d. Transient Event Insper. tion An inspection shall 0,e perfnamed of all hydraulic and mechanical

' snubbers attached to sectin7s of systems that. have experiet.:ed

,"" Unexpected, potentially t'ampging transients as determined f rom a .

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O q; h. l.. -. M thin 6 months foll >winq such anInevent.; addition?tonview of operational satisfying

, r. w the visual inspection acceptance criteria, freedomoof-motion of M -

.mir:haatcal snubbers shall be verified usir.g at least one of the

, , following: (1) manually induced snubber movement; or (2) evaluation COPY NO. 4 ic place snubber piston setting; or (3) stroking the mechanical snubber threuph its full range of travel.

"The inspection interval for each type of snubber on a given system shall not be lengthened more than one step at a time unless a generic problem has been identified and corrected; in that event the inspection interval may be

engthened one step the first time and two steps thereafter if no inoperable pnubbers of that type are found on that system.

1. The provisions of Specification 4.0.2 are not applicable.

WATERFORD - UNIT 3 3/4 7-22 AMENDMENT NO. 2

PLANT SYSTEMS SURVEILLANCE REOUIREMENTS (Continued)

e. Functional Tests '

During the first refueling shutdown.and at least once per 18 months thereaf ter during shutdown, a representative sample of snubbers shall be tested using one of the following bample plans. The sample plan shal) the sestbe period.

selected prior to the test period and cannot be changed during The NRC Regional Administrator shall be notified in

' writing of the sample plan selected prior to the test period or the sample plan used in the prior test period shall be implemented:

1) At least'10% of the total uf ea:h type of snubber shall be func- I tionally testod either in place or in a bench test. For each  !

snubber of a type that Joes not iacet tbc functional test accept- '

anco criteria of Specif cation 4.7.8f. . an additional 10% of that type of snubber shall be functionally tusted until no more failures are found or until all snubbero cf th.:t type have been functionally ;

tes+,ed; or j

2) A representative samplo of each type of snubber shall be func-tionally te;ted in accordance with Figure 4.7-1. "C" is the total number of snubbt rs of a type found not meeting the accep-tance requi.*emer ts of $pecification 4.7.8f. The cumulative number of snub F s of a type tested is denoted by "N". At the end of each da testi.g, the new values of "N" and "C" (pre-vious day's t: ,1 plus current ~ day's inertments) shall be plotted on Figure 4.7-1. If at any time the point plotted' falls in the " Reject" region all snubbers of that type shall be functionally tested.- If at any time the point plotted falls in the " Accept" region, testing of snubbers of that type may be terminated. When the point plotted lies in the " Continue Test-ing" region, additional snubbers of that type shall be tested until the point falls in.the " Accept" region or the " Reject" region, or all the snubbers of that type have been tested. Test-ing equipment failure during functional testing may invalidate that day's testin0 and allow that day's testing to resume anew at a later time, providing all snubbers tested with the failed equipment during the day of equipment failure are retested; or

3) An initial representative sample of 55 snubbers shall be function-ally tested. For each snubber type which does not meet the func-tional test acceptance critoria, another sample of at least one-half the site of the initial sample shall be tested until the total number tested is equal to the initial sample si:e multiplied by the factor, 1 + C/2, where "C" is the number of snubbers found which do not meet the functional test acceptance criteria. The results from this sample plan shall be plotted using an " Accept" line which follows the equation N = 55(1 + C/2). Each snubber point should be plotted as soon as the snubber is tested. If the point plotted falls on or below the " Accept" line, testing of that type of rdber may be terminated, If the point plotted falls above the " Accept" line, testing must continue until the point falls in the " Accept" region or all the snubbers of that type have been tested.

WATERFORD - UNIT 3 3/4 7-23

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PLANT SYSTEMS

-SURVElttANCr,$EOUIREMENTS (Continued)

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The representative sample selected for the functional test sam 9'e plans shall be randomly selected from the snubbers of each type and reviewed befot.) beginning the testing. The review shall ensure as i far as practical that they are representative of the var.ous con-figurations, operating environments, range of site. ano capacity of ,1 O ubbers of each type. Snubbers placed in the stie lccatit is us

.s.ubbers which failed the previous functional test shall b. retestei et the time of the next functional test but shall net be 1.1cludej i the sample plan. If during the functional testing, additinnal

' sampling is required due to failure of only one tWpe of snusber, the functional testing results shall be reviewed at the t1 e to deter +

mint if additional samples should be lim'eted to .the type ef t Jaber which has failed the functional testing.

f .- -- Functional Test AcceDtance Criteria The snubber functional test shall verify that

1) Activation (restraining action) is achieved within the specified range in both tension and compression;

2) Snubber bleed, or release rate where required, is pr9sent it both tension and compression, within the specified range; ,

3) Where required, the force required to initiate or m it ain tot *on of the snubber is within the speciffed range 11 both directions of travel; and

4) For sr.ubbers specifically required ico to disp roce ur.de -

continucus load, the ability of .the soubber to witt stant load without displacement.

Testing methods may be used to meas.re paismat4 rs indirectly or parameters other than those specified if those reso.ts can bs '

correlated to the specified parameters throygh establivu $ methods.

g. Functional __ Test Failure Analysis An engineering evaluation shall ~)e made of each f Lif ure to meet the functional test acceptanco cr teria to determine the cause of the failure. The resulta of this evaluation shall be used, if applicable, in selecting snubbers to be tested in an effort to determine the OPERABILITY of otntr snubbers 'rrespective of type which may be subject to the Jame failure mode.

For the snubbers found inoperablo, an engineering evaluation stiall be per#: rmed on the components to which the inoperable snubbers are attached. The purpose:of this engineering evaluation shall be to determine if the componet.ts to which the inoperable snubbers are i atta:hed were adversely affected by the incperability of the snubbers in order to ens' ire that the component remains capable of meeting the 1)asigned service.

WATERFORD -' UNIT 3 3/4 7-24 i

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i SURVE!LLANCE RE001 REM.F.NTS (Continued)

If any snubber selected for functional testing either fails to ,

lock up or fails to move, i.e., frozen-in place, the cause will be 1 evaluated and if caused by manufacturer or design deficiency all snubbers of the same type subject to the same defect shall be func-tionally tested. This testing reouirement shall be independent of {

the requirements stated in Specification 4.7.8e. for snubbers not i t

meeting the functional test acceptance criteria.  ;

h. Functional Testino of Repaired and Replaced Snubbers i

-Snubbers which fail the visual inspection or the functional test acceptance criteria shall be repaired or replaced. Replacement snubbers and snubbers which have repairs which might affect the functional _ test result shall be tested to meet the functional te'.t  !

criteria before installation in the unit. Mechanical snubbers shall '

have met the acceptance criteria subsequent.to their most recent service, and the freedom of-motiov test must have been performed i within 12 months before being installed in the unit.

i, Snubb'er Seal' Replacement Program '

The service life of hydraulic and mechanical snubbers shall be moni- i 1

tored veillance to ensureinspections. that the service life is not exceeded between sur-The maximum expected service life for various seals, springs, and other critical parts shall be determined and established based on engineering information and shall be extended ,

or shortened based on monitored test results and failure history. -

Critical parts shall be replaced so-that_the maximum service-life will not be exceeded during a period when the snubber-.is required to be

'0PERABLE. :The parts replacements shall be documented and the docu-mentation shall.be retained in accordance with Specification 6.10.3. 3 9

WATERFORD - UNIT 3 3/4 7-25

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8 7

REJECT 6

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" / TESTING ,

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1 ACCEPT r '

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, s 0 .10 20 30 40 50 60 70 80 90 100 N

FIGURE 4.7-1 SAMPLING PLAfd FOR SNUBBER FUNCTI0tiAL TEST WATERFORD - UNIT 3 3/4 7-26 v -e -

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' PLANT SYSTEMS BASES CONTROLLED VENTILATION AREA SYSTEM (Continued)

Operation of the system with the heaters on for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> continuous over a .11-day period is sufficient to reduce ths buildup of moisture on the adsorbers and HEPA filters. Obtaining and analyzing charcoal samples after 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of adsorber operation (since the last sample and analysis) ensures that the aasorber is consistent maintainsGuide with Regulatory the efficiency 1.52. assumed in the safety analyses and 3/4.7.8 SNUBBERS All snubbers are requirea OPERABLE to ensure that the structural integrity of the reactor coolant system and all other safety-related systems is maintainea during and following a seismic or etner event initiating cynamic losas.

related systems and then only if their failure or f ailure of th wnich system. they are installed, would have no adverse effect on any safety-relatea size. Snubbers are classified and grouped by design end manufacturer but not by For examole, the 2-kip,10 . '.p. mechanical snubbers utilizing the same design features of same type. and 100-kip capacity manuf actureo by Company "A" are of the The same design mechanical snubbers manufactured by Company "B" for the purposes of this Technical Specification would be of a different type, as would hyaraulic snubbers from either manufacturer.

A list of individual snuobers with detailed information of snubber locat with Section 50.71(c) of 10 CER Part 50.and size and of system affected sha The accessibility of eacn snuober shall be cetermir 1 and approved by the Plant Ooerations Review Comm1ttee.

The determination snall be based upon the exist.ng raaiation tevels and the expectea time to perform a visual inspection in each snubber location as well as otNr factors associated with accessibility curing plant operations (e.g.,

temperature, Guides 8.8 ana atmosonere, 8.10. location, etc.), and the recommendations of Regulatory The addition or deletion of any hydraulic or mecnanical snubber snall be mace in accordance with Section 50.59 of 10 CFR Part 50.

.The visusi inspection frecuency is based upon maintaining a constant level of snubber protection to each safety-related system. Therefore, the required -inspection interval varies inversely with- the observed snubber failures on a given system ano is determinea by the numoer of inoperable snubbers founo during an inspection of each system. In order to establish the inspection frequency for each type of snubber on a safety related system, it was assumed that the frequency of snubber failures ano initiating events is constant with time and that'the f ailure of any snubber on that system could cause the system to be unprotectea anc to result in failure during an assumeo initiating event.

Inspections performec before that interval has elapsed may be useo as i

WATERFORD - UNIT 3 B 3/4 7-5

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r PLANT SYSTFHS BASES ENUBBERS (Continued) a new reference point to determine the next inspection. However, the results of such early inspections performed before the original required time interval has elasped (nominal time less 25%) may not be used to lengthen the required it+)ection interval.

interval will override the crevious schedule.Any inspection whose results require ,

The acceptance criteria are to be used in the visual inspection to determine OPERABILITY of the snubbers. For example, if a fluid port of a hydraulic snubber is found to be uncovered, the snubber shall be declared inoperable and shall not be determined CPERABLE via functional testing.

To provide assurance of snubber functional reliability one of three functional testing methods are useo with the stated acceptance criteria: t

1. t Functionally test 10% of a type of snubber with an additional 10%

tested for each functional testing failure, or 2.

Functionally test a sample size and determine sample acceptance or rejection using Figure 4.7-1, or 3.

Functionally test a representative sample site and determine sample acceptance or rejection using the stated equation.

Figure 4.7-1 was developed using "Wald's Seouential Probability Ratio Duncan.as described in " Quality Control ano Industrial Statistics" by Acheson J.

Plan" Permanent or other exemotions f rom the surveillance program for individual snubbers may be granted by the Commission if a justifiable basis for exemption is presented and, if applicable, snubber life oestructive testing was performed to qualify the snubbers for the applicable design conditions at either the completion of their f abrication or at a subsequent date. Snubbers so exempted shall the be listed exemptions. in the list of individual snubbers indicating the extent of L The service life of a snubber is established via manufacturer input and information through consideration of the snubber service conditions ano associated l instollation and maintenance records (newly installed snubber, seal replaced.

spring replaced, in high radiation area, in high temperature area, etc.). The requirement to meditor the snubber service lif t is included to ensure that the snubbers and periodically operating conditions. undergo a performance evaluation in view of their age These recoros will provide statistical bases for future consideration of snubber service life.

WATERFORD - UNIT 3 P 3/4 7-6

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PLANT SYSTEMS 3/4.7.8 SNUBBERS llMITING CONDITION FOR OPERATION 3.7.8 All hydraulic and mechanical snubbers shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3 and 4 MODES 5 and 6 for snubbers located on systems requi ed OPERABLE in those OPERATIONAL MODES.

ACTION:

With one or more snubbers inoperable on any system, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> replace or restore the inoperable snubber (s) to OPERABLE status and perform an engineering evaluation per Specification 4.7.89, on the attached component or declare the attached system iroperable and follow the appropriate ACTION statement for that system.

_ SURVELLIANCE REQUIREMENTS 4.7.8 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

h Inspection Types '

Asw sed in this specification, type of snubber shall mean snubb o of th b ame design and manufacturer, irrespective of capacp .

b. Visual in ons

/

Snubbers are categoffred as inaccessible or Accessible during reactor

' operation. Each of theslesroups (inacSedble and accessible) may be _

o4he schedule below. The first inspected independently inservice visual inspection op according)h4ype e&c of snubber shall be performed after 4 months

• b L withjndD months o'f' commencing POWER OPERATION and shall include all yh dra'ulic and mechanica1'1;nubbers. If all snubbers of each type orjany system are found OPERABLE duHog the first inservice visual inspecfion, the second inservice visual inspeEtiqn of that systep4fiall be performed at the first refueling outage. Otherwise, s f,ubdquent visual inspections of a given system shall be performe(in

. / accordance with the following schedule: K_

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• VTsuiT- TMpertion-of-theJo .xcis_ible snubbe_ts_can__be-performed atMfie'Ti rst available_ outage-af-teed r at R of commencf50 f'Uwer4perat4cn- _

WATERFORD - UNIT 3 3/4 7-21 AMENDMENT NO. 2

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PLANT SYSTEMS SURVE!LLANCE REQUIREMENTS (Continued)

No. of Inoperable Snubbers of Each Type Subsequent Visual [

n Any System per Inspection Period Inspection _ Period **#

O 18 months 2 25% .

I 12 months i 2' 2 6 months 5%

4 124 da 1 25%

5, 62 ys 1 25%

8 or e days i 25% 1

c. Visual Inspection Acc Rtance Criteria t

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Visual inspections shall fy that:/(1) there are no visible indications of damage or b r a d RABILITY and (2) attachments to the foundation or supporting sty ure are secure, and (3) fasteners for attachment of the snubbeydo the omponent and to the snubber anchorage are secure. Sn ers which ear inoperable as a result of visual inspections , be determined RABLE for the purpose of establishing the ne visual inspection inte al, provided that:

-(1) the cause of he rejection is cleart. estab shed and remedied -

for that part ar snubber and for other snubber rrespective of type on th system that may be generically suspecti 4; and (2) the i affecte nubber is functionally tested in th? as-foun ,ndition and dete ned OPERABLE per Specifications 4.7.8f. All snubbe connected inoperable common hydraulic fluid reservoir shall be co ted as operable snubbers. For those snt"*rs comon to more than on ,

system, the OPERABILITY of such snE Nrs shall be considered in assessing the surveillance schedule for each of the related systems, s

d. + Transient Event Insnection ,

An inspection shall be performed of all hydraulic and mechanical snubbers attached to sections-of systems that have experienced

O j i Q expected, potentially danaging transients as. determined from a t i . 4 -

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• .,ytview Mthin 6ofrionths operational data following such andan'a event. visual inspection In addition of to thesatisfying systems

g. On. y. the visual inspection acceptance criteria, freedom-of-motion of

,mecnanicai snubbers shsil-de verified using at least one of the following: (1) manually induced snubber movement; or (2) evaluation COPY NO. '/g/) as in place snubber piston settings or (3) stroking the mechanical snubber through its full' range of travel.

7The4 ction interval for each type of snubber on a given syste 6 be lengthene 4 han one step at a time unless a ene.rle- o lem has been identified and correc'tir;H n dhat event the on interval may be lengthened one step-the first ti h :t steps thereafter if no inoperable pnubbers of-that type rM n on that syste . .

1. sions of Specification 4.0.2 are not applicable. -

WATERFORD - UNIT 3 3/4 7-22 AMEN 0 MENT NO. 2 l

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. , . INSERT A l' age 1 of 3

a. In_spection Types As used in this specification, " type of snubber" shall mean snubbers of the samo design and manufacturer, irrespective of capacity.

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b. Visual luspections  ;

Snubbers are categorized as inaccessible or accessible during reactor l operation. Each of these categories (inaccessible and accessible) may be ,

inspected independently according to the scheduto determined by Table  !

4.7-2. The visual luspection interval for each type of snubber shall be -

determined based upon the criteria provided in Table 4.7-2 and the first  !

inspection interval determined using this criterhi shall be based upon the  ;

previous inspection interval as established by the recluirements in effect >

before amendment ('). s

• NRC willinclude the number of license amendment that implements this change.

c. Visual Inspection- Acceptance Criteria Visual inspections shall verify that (1) the snubber has no visible indications of damage or impaired OPERADILITY, (k) attachments to the foundation or supporting structure are functional, and (3) fasteners for the attachment of the snubber to the component and to the snubber

- anchorago are functional. Snubbers which appear inoperable as a result of ,

visual inspections shall be classified as unacceptable and may be reclassified acceptable for the purpose of establishing the next visual inspection interval, provided that (1) the cause of rejection is clearly established and remedied for that particular snubber and for other snubbers irrespective of type that may be generically susceptible; and (2) the affected snubber is functionally tested in the as-found condition and determined OPERAllLE por Specification 4.7.8f. - 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.

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TAllLI: 4. 7-2 SNUllllEH VISUAL INSPECTION INTERVAL l Nt1MilEH OP UNACCEPTAllLE SNUllllERS population Column A Column 11 Column C  ;

or Category Extend Interval Hepeat interval Hedur Interval t (Notes 1 & 2) (Notes 3 & 0) (Notes 4 & 0) (Noten 5 & G),

1 0 0 1 80 0 0 2 100 0 1 4 150 0 3 8 200 2 5 13' 300 5 12 25 400 8 18 3G 500 12 24 48 t 750 20 40 78 10001r greater 29 50 109 ,

Note 1: The next visualinspection Interval for a snubber population or category size shall be determined based upon the previous inspection interval and the number of unacceptable snubbers found during that interval. Snubbers may be categorized, based upon their accessibility during power operation, as accessible or inaccessible.

These categories may be examined separately or jointly, llowever, the licenseo must make and document that deelslon before any inspection and shall use that decision as the basis upon which to determine the next inspection interval for that category.

Note 2: Interpolation between population or category sizes and the number of unacceptable snubbers is permissible. Use next lower integer for the value of the limit for Columns A,11, or C if that integer includes a fractional value of unacceptable snubbers as determined by interpolation.

Note 3: If the number of unacceptable snubbers is equal to or less than the number in Column A, the next inspection interval may be twico the previous interval but not greater than 48 months.

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Note 4: If the number of unacceptable snubbers is equal to or less than the number in Colunni Il but greater than the ntunber in Column A, the I next hu,pection interval shall be the same as the previous interval.

Note 5: If the number of unacceptable snubbers is equal to or greater than l the number in Column C, the next inspection interval shah be two-thirds of the previous interval, llowever, if the number of unneceptable snubbers is less than the number in Column C but greater than the number in Column 11, the next interval shall be reduced proportionally by interpolation, that is, the previous ,

interval shall be reduced by n factor that is one-third of the ratio of I the difference between the number of unaccer aable snut.bers found during the previous interval and the numNr in Column !! to the difference in the numbers in Cohuans 11.ind C.

Note G: The provisions of Specification 1.0.2 are applicable for all inspection intervals up to and including 48 months.

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e PLANT SYSTEMS SURVEILLANCE RE001REMENTS (Continued)

e. Functional Tests '

During tha first refueling shutdown and at least coce per 18 months thereaf ter during shutdown, a representative sample of snubbers shall be tested using one of the following sample plans. The sample plan shall be selected prior to the test period and cannot be chan3ed during the test period. The NRC Regional Administrator shall be notified in writing of the sample plan selected prior to the test period or the sample plan used in the prior test period shall be implemented:

1) At least 10% of the total of each type of snubber shall be func-tionally tested either in place or in a bench test. For each snubber of a type that does not meet the functional test accept-ance criteria of Specification 4.7.8f., an additional 10% of that type of snubber shall be functionally tested until ro more failures are found or until all snubbers of that type have been functionally tested; or

2) A representative sample of each type of snubber shall be func-tionally tested in accordance with Figure 4.7-1. "C" is the total number of snubbers of a type found not meeting the accep-tance requirements of Specification 4.7.8f. The cumulative number of_ snubbers of a type tested is denoted by "N". At the end of each day's testing, the new values of "N" and "C" (pre-vious day's total plus current ~ day's increments) shall be plotted on Figure 4.7-1. If at any time the point plotted falls in the " Reject" region all snubbers of that type shall be functionally tested. If at any time the point plotted falls in the " Accept" region, testing of snubbers of that type may be terminated. When the point plotted lies in the " Continue Test-ing" region, additional snubbers of that type shall be terted until the point falls in the " Accept" region or the " Reject" region, or all the snubbers of that type have been tested. Test-ing equipment failure during functional testing may invalidate that day's testing and allow that day's testing to resume = anew at a later time, providing all snubbers tested with the failed equipment during the day of equipment failure are retested; or

3) An initial representative sample of 55 snubbers shall be function-ally tested. For each snubber type which'does not meet the func-

_tional_ test acceptance criteria,-another sample of at least one-half the size of the initial sample shall be tested until the total number tested is equal to the initial sample size multiplied by the f actor,'1 + C/2, where "C" is the number of snubbers found which do nnt meet the functional test acceptance criteria. The results from this sample plan shall be plotted using an " Accept" line which follows the equation N = 55(1 + C/2). Each snubber point should be plotted as soon as the snubber is tested. If the point plotted falls an or below the " Accept" line, testing of that type of snubber may be terminated. If the point plotted falls above the " Accept" line, testing must continue until the point falls in the " Accept" region or all the snubbers of that type have been tested.

WATERFORD - UNIT 3 3/4 7-23 i

'I

__m--__ m---________C.- - _ - _ - - - - - - - - _ _ - - - - - - - - - - - - -

'~

PLANT SYSTEMS SURVEILLANCE REOUIREMENTS (Continued)

The representative sample selected for the f anctional test sample plans shall be randomly selected from the $4ubbers of each type and re'<iewed before beginning the testing. The review shall ensure as far as practical that they are representatine of the various con-figu*ations, operating environments, range of size, and capacity of snublers of each type. Snubbers placed its the same locations as snubbers which failed the previous functional test shall be retested at the time of the next functional test tut shall not be included in the sample plan. . If during the functional testing, additional sampling is required due to failure of enly one type of snubber, the functional testing results shall be reviewed at the time to deter-mine if additional samples should be limited to the type of snubber which has failed the functional testing,

f. Functional Test Accentance Criteria The snubber functional test shall verify that:

1) Activation (restraining action) is achieved within the specified range in both tension and compression;

2) Snubber bleed, or release rate where required, is present-in both tension and compression, within the rpecified range;

'3) Where required, the force required to initiate or maintain motion of the snubber is within the specified range in both directions of travel; and

4) For snubbers specifically required not to displace under continuous lotJ the ability of the snubber to withstand load without displ ir ",t Testing methods may be used to measure parameters indirectly or parameters other .than those specified if those results can be correlated to the specified parameters through established methods.

I

. g. Functional Test Failure Analysig An engineering evaluation shall be made of each ailure to meet tne lunctional test accaptance criteria to determine the cause of the

?411ure, The results of this evaluation shall be u ed, if applicable, in selecting snubbers to be tested in an effort to determine the OPERABILITY of other snubbers irrespective of type which may be subject to the same failure mode.

For the snubbers found inoperable, an engineering evaluation shall be performed on the components to which the inoperable snubbers are attached. The purpose of this engineering evaluation shall be to

.detarmine it the components to which the inoperable snubbers are attached were adversely affected by the inoperability of the snubbers

-in order to ensure that thin component remains capable of meeting the designed service.

WATERFORD - UNIT 3 3/4 7-24 1

I .

1 PLANT SYSTEMS SURVEILLANCE RE0VIREMENTS (Continued)

If any snubber selected for functional testing either fails to lock up or fails to move, i.e., frozen-in place, the cause will be evaluated and if caused by manufacturer or design deficiency all snubbers of the same type subject to the same defect shall be func-tionally tested. This testing requirement shall be independent of the. requirements stated in Specification 4.7.8e. for snubbers not meeting the functional test acceptance criteria.

h. Functional Testina of Repaired anc Replaced Snubbers Snubbers which fail the visual 'rtpor

• ion or the functional test

-e acceptance criteria shall be r4 -

a or replaced. Replacement snubbers and snubbe.: or ch have repairs which might affect the functional test result shall be tested to mcat the functional test criteria before installation-in the unit. Mechanical snubbers shall have met the acceptance criteria subsequent to their most recent service, and the freedom-of-motion test must ave been performed within 12 months before being installed in the unit.

i. Snubber Seal Replacement Program The service life of hydraulic and mechanical snubters shall be moni-tored to ensure that the service-life is not exceeded between sur-veillance inspections. The maximum expected service life for various

- seals, &prings, and other critical parts sball be c ?termined and established based on engineering information and shall be extended or shortenec based on monitored test results and failure history, c Critical parts shall be replaced so that the maximum service life will not be exceeded duridg a period when the snubber is required to be OPERABLE. The parts replacements shall be documented and the docu- -

mentation shall be retained in accordance with Specification 6.10.3.

i l

WATERFORD - UNIT 3 3/4 7-25

10 ,

9 8

7.

REJECT 6 r j

lx C 5 CONTINUE 2 [ TESTING ,

f 2 / --

1 ACCEPT r

0 10 20 30 40 50 60 70 80 90 100 N

FIGURE 4.7-1 SAMPLING PLAN FOR SNUBBER FUNCTIONAL TEST WATERFORD -- UNIT 3 3/4 7-2G

PLANT SYSTEMS BASES CONTROLLED VENTILATION AREA SYSTEM (Continued)

Operation of the system with the heaters on for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> continuous over a 31-day adsorbers periodfilters.

and HEPA is sufficient to recuce the buildup of moisture on the Obtaining and analyzing charcoal samples after 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of adsorcer operation (since the last sample ano analysis) ensures that the adsorber is consistent maintains with Regulatory the1.52, Guide efficiency assumeo in the safety analyses and 3/4.7.8 SNUBBERS All snubbers are required OPERABLE to ensure that the structural integrity of the reactor during and coolant following a seismic system orandotnerallevent other safety relateo systems is maintainea initiating cynamic loads.

Snubbers excludea from this inspection program are those installed on nonsa related systems and tnen only if their failure or failure of the system on which system. they are installed, would have no aaverse effect on any safety rel t a ea size. Snubbers are classified and grouped by cesign and manufacturer but not by For example, mechanical snubbers utilizing the same design features of the 2-kip,10-kip, same type. and 100-kip capacity manufactured by Company "A"are of the The same design mechanical snubbers manufacturea by Company "B" forwould as the purposes of this from hydtculic snubbers Technical Specification either manufacturer. would be of a different type and size and of system affectea shall be available at the pla with Section 50.71(c) of 10 CFR Part 50. The accessibility of eacn snuocer shall be cetermined and approved by the Plant Operations Review Committee.

The cetermination shall be cased upon the existing radiation levels anc the expectea time to perform a visual insoection in eacn snubber location as well as other factors associated with accessibility curing plant operations (e.g. ,

temperature, Guides atmospnere, 8.8 and 8.10. location, etc.), and the recommendations of Regulatory The addition or deletion of any hydraulic or mecnanical snubber shall be made in accordance with Section 50.59 of 10 CFR Part 5 level of s nobar orotection to eacn safety related system. visual insp required inspect 1o There' , the on a given system and iserval varies inversely with the oos minea by the numcer snuober failures during an inspection of each sys perable snubbers found frequency for eacn type of snuober o n or ar so establish the inspection l

that the frequency of snuobe ~

. -related syscem, it was assumed t

time and that the fai ures and init1 . events is constant with t any snubber on that system l to be unprot yt: no to result in failure during an assumeo incause the system event.

'nspections performed before that interval has elapsed may being s INSERT B \ #

WATERFORD - UNIT 3 B 3/4 7-5

.- . ..._.._..m . . . . _ . . _ _ . _ _ _ . _ - . _ . _ _ _ _ _ _ . . _ . _ _ _ - _ _ _ . . _ - . _ - _ . . . . . _ _ ,

INSERT 11

!^

Guidaneo or visualinspection is provided in NRC Generic Letter 90-09. _ A visual inspection is the observation of the condition of installed snubbers to identify those that are damaged, degraded, or inoperable as caused by physical means, leakage, corrosion, or environmental exposure. The functional testing program provides a 95 percent confidence level that 90 to 100 perecut of the snubbers will operate within the specified acceptance limits. The performanco of visual _

exuminations is a separate process that complements the functionel testing

_ program and provides additional confidence in snubber operability.

The vhual inspection schedule (as determined by Tablo 4.7-2) is based on the number of unacceptable snubbers found during the previous inspection in proportion to the sizes of the various snubber populations or categories. A

- snubber is considered unacceptable if it falls the n'eceptance criteria of the visual I inspection. - The inspection interval is based on a fuel cycle of up to 24 months and may.be as long as two cycles, or 18 months for plants with other fuel cycles, depending on the number or unacceptable snubbers found during the previous i visual hispection.

t

-I PLANT SYSTEMS l BASES

.~ _,_

SNUBBERS (Continued) h int to determine the nnxt inspection.

However N its of such early inspect ed before the has elasped (nominal time less ? utred time interval inspection inte .

sed to lengthen the required

_Lntary pecticn whose results r s_a_ orter inspection override the previous schedule.

The acceptance criteria are to be used in the visual inspection to determine OPERABILITY of the snubbers. For example, if a fluid port of a hydraulic snubber is found to be uncovered, the snubber shall be declared inoperable and shall not be determined OPERABLE via functional testing.

To provide assurance of snubber functional reliability one of three furctional testing methocs are used with the statea acceptance criteria:

1.

Functionally test 1C% of a type of snubber with an additional 10%

tested for each functional testing failure, or 2.

Functionally test a sample size and determine sample acceptance or rejection using Figure 4.7-1, or 3.

Functionally test a representative sample size and determine sample acceptance or rejection using the stated equation.

Figure 4.7-1 was developed using "Wald's Sequential Probability Ratio Duncan,as described in " Quality Control anc Incustrial Statistics" by Acheson J.

Plan" Permanent or other exemptions from the surveillance program for individual snubbers may be granted by the Commission if a justifiable basis for exemption is presented and, if applicable, snubber life cestructive testing was performea to qualify the snubbers for the applicscle design conditions at either the completion of their faorication or at a subsequent cate. Snubbers so exempted shall the be listed exemptions. in the list of individual snubbers indicating the extent of The service life of a snubber is established via manufacturer input and information througn consideration of the snubber service conditions and associated installation and maintenance records (newly installed snubber, seal replaced,

- spring replaced, in high radiation area, in high temperature area, etc. ). The

- requirement to monitor the snubber service life is included to ensure that the snubbers and periodically operating undergo a performance evaluation in view of their age conditions. These records will provide statistical bases for future consideration of snubber service life.

WATERFORD - UNIT 3 B 3/4 7-6