ML20070W019

Proposed Tech Specs Re Schedule for Snubber Visual Insp

ML20070W019
Person / Time
Site:	Catawba
Issue date:	04/02/1991
From:	DUKE POWER CO.
To:
Shared Package
ML20070W018	List: ML20070W016 ML20070W019
References
GL-90-09, GL-90-9, NUDOCS 9104120281
Download: ML20070W019 (14)

Text

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l Attachment I Proposed Technical Specification Changes l

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l 9104120281-9104Q2 l PDR ADOCK 05000413 P PDR l

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PLANT SYSTEMS 3/4.7.8 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.8 All snubbers shall be OPERABLE. Tt.e only snubbers excludea from the requirements are those installed on nonsafety related systems and then only if their failure or failure of the system on which they are installed would have no adverse effect on any safety-related system.

APPLICABILITY: MODES 1, 2, 3, and 4 MODES $ and 6 for s.nubbers located on systems required OPERABLE in those MODES.

ACTION:

With one or more snubbers inoperable, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> replace or resto- the inoperable snubber (s) to OPERABLE status and perform an engineering ev41uation per Specification 4.7.89. on the attached component or declare the attached system inoperable and follow the appropriate ACTION statement for that system.

SURVE!LLANCE REQUIREMENTS 4.7.2 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program in lieu of the requirements of Specification 4.0.5.

a. Inspection Types .

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As used in this specificatio ,* type of snubber hall mean snubbers of the same design and manufa ft4ftv1$ . ve of capacity,

b. Visual Inspections I

Snubbers are cate orized as inaccessible or accessible during reactor

\ ND k*' operation.4-T ttt-inteev4ee-v4tuel--4nspection ef e:ch-type-et taubbee-theM-be-perfermed-efree-4-months-but%Hhir 10 ,0ntht-ef-

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l See Nached commenc+ng-POWER-OPERATHM-e nd-t heH4nc+u de-eH-hydreuMe-end-mechen-ki 4.

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Jisve E, , ,,4-4nspect4en-theH-+e-pe rf or

= the dete-of-the-f4ett4nspec-t4ent--Otherwi+e -subsequent-v46ual-4m r spectrient-sham-be-pe nfo rmed-4n-acc o rea not-w l t h-t he-f4440wi-n9-

-teheew4e+-

' Subsequent Visual

. f Inoperable Snubbers of Each Type nuncL0urina Inspection InspectionJer+Yd4 i {N 5 % ,$

o s' 0 lLmonths 2 2 2

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1 f 12 months i 25%

[ See e O n ked 2

,N 6 months 2 25%

ays t 25%

3,4 r more 1d ,

"The7nspeet4cn interval for each type of sn.;bber shall not jbe igthene F more than one step at a timir un4ess a ceneri: pr_9blan-herbeen identified and corrected; in that even jt thaspeett W 1tYfva4-may h Q hened one '

step the first t a--ane-tw steps thereaf ter if no inoperable snubTirtr-ef-

~that -typ .e ound.

!The prov4+40ns-of4 pec&ffeat4on 4.0.1 are not-appH emble.

4 INSERT A I

Each of these categories (inaccessible and accessible) may be inspected independently I

according to the schedule determined by Table 4.7 2. The visual inspection interval for cach category of snubber shall be determined based upon the criteria provided in Table 4.7 2 and the first inspection interval determined using this criteria shall be based upon the previous inspection interval as established by the requirements in effect before amendment (*).

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

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l N S E.E T T I TaLie 4.7-2 l SNUBBER VISUAL INSPECTION INTERVAL NUMBER OF UNACCEPTABLE SNUBBERS Population Column A Column B Column C or Category Extend Interval Repeat Interval Reduce Interval

_(Notes 1 and 2) (Notes 3 and 6) (Notes 4 and 6) (Notes 5 and 6) 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 36 500 12 24 48 750 20 40 78 1000 or greater 29 56 109 l

Note 1: The next visual inspection interval for a snubber population or cate-gory 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 categor-1es may be examined separately or jointly. However, the licensee must make and document that decision 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 s!zes and the number of unacceptable snubbers is permissible. Use next lower integer for the value of the limit for Columns A, E, or C if that integer includes a fractional value of unacceptable snubbers as determined by inter-polation.

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

Note 4: If the number of unacceptable snubbers is equal to or less than the number in Column B but greater that the number in Column A, the next inspection interval shall be the same as the previous interval.

, l0SEM "N Toue 4.7 - ?_ ( ano a)

SA01LBk.1L VL50k \QGTBTIDO 14 TEIN A L.

Note 5: If the number of unacceptable snubbers is equal to or greater than the number in Column C, the next inspection interval shall be two-thirds ~

of the previous interval. However, if the number of unacceptable snubbers is less than the number in Column C but greater than the number in Column 8, the next interval shall be reduced proportionally by interpolation, that is, the previous interval shall be reduced by a factor that is one-third of the ratio of the difference between the ,

number of unacceptable snubbers found during the previous interval and the number in Column B to the diffarence in the numbers in Columns 8 dhd C.

i Note 6: The provisions of Specification 4.0.2 are applicable for all inspec.

tion intervals up to and including 48 months.

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ad (,3) [os4 coevs 8tv Oc DNochmed e ne PLANT SYSTEMS  %&,ev +e ihc. ccm puwcf anci 4t. ec sraWev

! SURVEILLANCE REQUIREMENTS (Continued) acheme W bM (*

c. Visual Inspection Acceptance Criteria { g'n[7  ;

Visual inspections shall verify that: (1 ^ - r e no visible indi-  !

cations of damage or impaired OPERABILITY .

tachments to the i foundation or supportir,g structure are func onalj+ Snubbers which l appear inoperable as a result of visual inspectionst r M 4:tcW:d ,

OICI C C:for the purpose of establishing the next visual inspection I l

c. intitul . Drovided. that: (-)-) the cause of the rejection is clearly establis i  !

snubbers (-1yJo a,J4yhat particular snubber type that may be generically susceptible; m and for other *  !

b

(( t a ecte n

_ and(t)io_na_nd_ determined 0PERABLE*s functionally tested in-the as foun er Specification 4.7.8f. -When-s condit

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d. Refuelino Outage Inspections m e'

At each refueling, the systems which have the potential for a severe 6 7!

dynamic event, specifically, the-Main Steam System (upstritam of the s  %:

main steam isolation valves) the main steam safety and power operated yl

. relief valves.and piping, Auxiliary Feedwater System, main steam supply 4i +:

, to the auxiliary feedwater pump turbine, and the letdown and charging portion of the CVCS System shall be inspected to determine if there has been a severe dynamic event. In the case of a severe dynamic

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event, mechanical snubeers in that system which experienced the event l shall be inspected during the refueling outage to assure that the  ;

mechanical sn'ubbers have freedom of movement and are not frozen up.

• l The inspection shall consist of verifying freedom-of-motion using one of the following: (1) manually induced-snubber movement; or (2) eval-uation of in place snubber piston setting; or (3) stroking the $

mechanical snubber-through its full range of' travel. If one or more J'

- mechanical snubbers are found to be frozen up during this inspection, those snubbers shall be replaced or repaired before returning to power. The requirements-of Specification 4.7.8b. are independent of h:

the requirements of this specification,

e. Functional Tests  ;

During the first refueling shutdown and at least once per 18 months ,

thereafter during shutdown, a representative sample of snubbers of I

each type shall be tested using one of-the following sample plans.

The large-bore steam generator hydraulic snubbers shall be treated as l

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CATAWBA - UNITS 1 & 2 3/4 7 20- Amendinent No. 52 (Unit 1)

Amendme'nt No. 45 (Unit 2) r m _ - -_,

1 INSERT C All snubbers found connected to an inoperable common hydraulle fluid reservoir shall be counted as unacceptabic and may be reclassided as acceptable for determining the iiext inspection interval provided that criterion (1) and (11) above are met. A review and evaluation shall be performed and documented tojustify continued operation with an unacceptable snubber, if continual operation cannot be justified, the snubber shall be declared inoperable and the ACTION requirements shall be met.

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! FOR INFORMATION ONLY PLANT SYSTEMS 4 SURVEILLANCE REQUIREMENTS (Continued)

e. Functional Tests (Continued) a separate type (population) for functional test purposes. A 10%

random sample shall be tested at least once per 18 months during refueling with cent,inued testing based on a failure evaluation. The sample plan snall ue selected prior to the test period and cannot-be changed i during the test period. The NRC Regional Administrator shall be noti-fied in writing of the sample plan selected for each snubber type prior to the test period or the sample plan used in the prior test period shall be imple!..ented:

1) At least 10% of all snubbers shall be functionally tested either in place or in a bench test. For each snubber of a type that does not meet the functional test acceptance criteria of Spe-cification 4.7.8f., an additional 10% of all snubbers shall be functionally tested until no more failures are found or until all snubbers have been functionally tested; or

2) A representative sample of all .snuboers shall be functionally tested in accordance with Figure 4.7-1. "C" is the total number of snubbers of a type found not meeting the acceptance require-ments of Specification 4.7.8f. The cumulative number of snub-bers tested is denoted by""N". At the end of each day's test-ing, the new values of "N and "C" (previous day's total plus

urrent day's increments) shall be plotted on Figure 4.7-1. .l 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 Testing!' region, additional l

snubbers of that type shall be tested until the point falls in j

the " Accept" region or all the snubbers of that type have been l tested; or

3) An initial representative sample of 55 snubbers shall be func-tionally tested. For-each snubber type which does not meet the functional test acceptance criteria, another seple 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 l

j size multiplied by the factor, 1 + C/2, where."C" is the number of snubbers found which do not meet the functional test accept-ance 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 may be terminated. If the point plotted falls above the " Accept" line, testing must continue until theipoint falls in the " Accept" region or all the snubbers of-that type have-been tested.

CATAWBA UNITS 1 & 2 3/4'7-21 Amendment Nc .;2 (Unit 1)

Amendment No. 45 (Unit 2)

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FOR INFORMATION ONLY PLANT SYSTEMS' SURVEltLANCE REQUIREMENTS (Continued) e, Functional Tests (Continued) g Testing equipment failure during functional testing may invalidate that day's testing and allow that day's testing to resume anew at a later time provided all snubbers tested with the failed equipment during the day of equipment failure are retestad. The representative sample selected for the functional test sample plans shall be random-ly selected from all snubbers and reviewed before % ginning the test-ing. The review shall ensure, as far as practicable, that they are representative of the various configurations, operating environments, range of size, and capacity of snubbers. Snubbers placed in tne same location as snubbers which failed the previous functional test shall be retested at the time of the next functional test but shall not be included in the sample plan. If during the functional testing, addi-tional sampling is required due to failure of only one type of snub-ber, the function 61 test results shall be reviewed at that ?,ime to '

determine if additional samples should be limited to the type of snubber which has failed the functional testing.

f, Functional Test Acceptance Criteria The snubber functional test shall verify that:

1) Activation (restraining action) is achieved within the specified range in both tension &nd compression, except that inertia de-pendent, acceleration limiting mechanical snubbers may be tested to verify only that activation taket lace in both directions of

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

3) For mechanical snubbers, 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 load, the ability of the snubber to withstand load without displacement.

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,

g. Functional Test Failure Analysis

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An engineering evaluation shall be made of each failure to meet the functional test acceptance criteria to determine the cause of the failure. The results-of this evaluation shall be used, 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, l

CATAWBA - UNITS 1_& 2 3/4 7-22 )

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FOR INFORMATION ONLY PLANT SYSTEMS SURVEILLANr.EREQUIREMENTS(Continued)

g. Functional Test Failure Analysis (Continued)

For the snubbers found inoperable, an engineering evaluation shall be performed on the components to which the inoperable snubbers are 1 attached. The purpose of this engineering evaluation shall be to 1 determine if the components to which the inoperable snubbers are I attached were adversely affected by the inoperability of the snubbers in ordar to ensure that the component remainc capabie of meating the designed service. ,.

If any snubbte selected for functional tetting O ther fails to lock up or fails to move, i.e., frozen-in place, the cause will be

' evaluated end, if caused by manufacturer or design deficiency, all snubbers of the same type subject to the same defect shall be fur.c-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 critatia.

h. Functional Testing of Reoaired and Replaced Snubbers 1

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 results shall be tested to meet the functional test criten a before installation in the unit. Mechanical snubbers shall have met the acceptance criteria subsequent te.their most recent service, and tN freedom-of-motion test must have been-performed within 12 months before being installed in the' unit.

i, Snubber Service Life Program f .

The service oerfomance of all snubbers shall be monitored. If a service lif.' 'mit is associated (established) with any snubber (or critical w a based on manufacturer's_information, qualification tests, or historical service results, then the service life shall be monitored to ensure that the service life is not exceeded between

> surveillance inspections. Established snubber service life shall be extended or shortened based on monitored test results and failure history. The replacements (snubbers or critical parts) shall be docu-mented and the documentation shall be retained in accordance with Specification 6.10.2..

CATAWBA - UNITS 1 & 2 3/4 7-23 l

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NO CH ANGE'S THis PAGE.

, FOR INFORMATION ONLY 10 9 .

8 7  :'

6 ---

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TESTING h

t ACCEPT 1 e

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

FIGURE 4.7-1 SAMPLE PLAN 2) FOR SNUBBER FUNCTIONAL TEST CATAWBA - UNITS 1 AND 2 3/4 7-24 Amendment 'to. 52 (linie 1)

Amendment Mo. 45 (Unit 2)

A'ITACHMENT 2 Duke Power Company Catawba Nuclear Station, Units 1 and 2 Just10 cation for Proposed Changes and Evaluation of No Significant Hazards Consideration JUSTIFICATION FOR PROPOSED CHANGF; The proposed amendment in this submittal includes changes to Section 4.7.8 of the Catawba Nuclear Station Technical Specifications, Snubbers, bared on guidance provided by Generic Letter 90 09 dated December 11,1990. Revisions to the wording of the Generic Letter 90-09 proposed Technical Specifications were made to maintain consistency with the current Catawba Technical Specification definition of snubber categorization and disposition of visual failures. These revisions were discussed with the NRC Staff prior to this submittal. Attachment I provides proposed revisions to Catawba Technical Specifications 4.7.8 b and 4.7.8 c. The proposed revisions would replace the current snubber visual inspection schedule with a new snubber visual inspection schedule, Table 4.7-2 of Attachment I, and revise the visual inspection acceptance criteria to mirror the visual inspection acceptance criteria contained in the Generic Letter.

The current schedule foi %1 inspections is based on the number of inoperable snubbers found during the previous visual inspection, irrespective of the size of the snubber population. Since Catawba Nuclear Station has a large snubber population, this visual inspection schedule has proven to be excessively restrictive. Complying with the visual examination schedule has resulted in the spending of a significant amount of

resources and subjecting plant personnel to unnecessary radiological exposure. This new schedule would maintain the same confidence level that the snubbers will operate within the specified acceptance levels and generally will allow visual inspections and corrective actions to be performed during plant outages.

This amendment, if implemented,.would reduce future occupational radiation exposure and would be highly cost effective. Such action is consistent with the Commission's policy statement on Technical Specification improvements. t Upon approval of this amendment request, the current snubber visualinspection schedules will be recalculated by taking the number of inoperable snubbers found in the previous visual inspection and applying the criteria in Table 4.7-2 of Attachment I. The results would be as follows:

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UNIT 1 UNIT 2 Accessible Inaccessible Accessible Inaccessible Number of Inoperable 0 0 1 0 Snubbers From 12st l Inspection:

Date of Last Inspection: 2/20/90 3/12/90 4/17/90 8/22/90 Current Inspection 18 month 18 month 12 month 18 month Interval:

Next Surveillance Date: 8/20/91 9/12/91 4/17/91 2/22/92 (25% extension) (7/17/91)

New Inspection Interval: 36 month 36 month 24 month 36 month New Surveillance Date: 2/20/93 3/12/93 4/17/92 8/22/93 NO SIGNIFICANT HAZARDS CONSlp,ERATION EVALUATION This proposed amendment would incorporate the guidance contained in the NRC's Generic Letter 90-09, dated December 11, 1990. The Generic Letter provided guidance for replacing the current snubber visualinspection schedule with an alternate snubber visual inspection schedule.

l This proposed amendment has been developed based on the Generic Letter guidance.

10 CFR 50.92 states that a prcgosed amendment involves no significant hazards considerations if operation in accordance with the propo.:ed 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 different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.

The proposed amendment does not involve an increase in the probability or consequences of any previously evaluated accident. This amendment provides an alternate schedule for the visual inspection of snubbers which maintains the same confidenc: level in the snubbers ability to operate within a specified acceptance level.

The accicent analyses are therefore unaffected by this proposal.

The proposed amendment does not create the possibility of a new or different kind of.-

accident from any accident previously evaluated since the coandence level in the 1 number of snubbers available has not been changed.

The proposed amendment does not involve a significant reduction in a margin of safety. . I This amendment provides an alternate schedule for the visual Inspection of snubbers which maintains the same confidence level in the snubbers ability to operate within a specified acceptance-level. The margin of safety is therefore unaffected by this proposal.

~I For the above reasons, Duke Power concludes that this proposed amendment does not :

involve any Significant Hazards Consideration, j

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The proposed TS change has been reviewed against the criteria of 10 CFR-51.22(c)(9) for environmental considerations.. The proposed change does not involve any significant ;

hazards consideration, nor % crease the types or amounts of effluents that may be '

released offsite, nor increas,v the individual or cumulative occupational radiation . l exposure. Based on this, the proposed Technical Specification change meets the criteria-given in 10 CFR 51.22(c)(9) for categorical exclusion from the requirement.for an-Environmental Impact Statement.

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