ML20072S775

Proposed Tech Specs 3/4.7.4 Re Visual Insp of Snubbers & Insp Interval

ML20072S775
Person / Time
Site:	Grand Gulf
Issue date:	04/10/1991
From:	ENTERGY OPERATIONS, INC.
To:
Shared Package
ML20072S774	List: ML20072S771 ML20072S775
References
NUDOCS 9104170067
Download: ML20072S775 (8)

Text

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f M -91/09 .

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' PLANT SYSTEMS 3/4.7.4 SNUBBERS i

LIMITING CONDITION FOR OPERATION 3.7.4 All snubbers shall be OPERABLE. The only raubbers excluded 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: OPERATIONAL CONDITIONS 1, 2 and 3.

OPERATIONAL CONDITIONS 4 CONDITIONS.and 5 for snubbers located on systems required OPERABLE in those OPERATIONA ACTION:

With one or more snuboers 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 evaluation per Specification 4.7.4 9 on the attached component or attached system. system inoperable and follow the appropriate ACTION statem?nt for that SURVEILLANCE REQUIREMENTS 4.7.4 Each snubber shall be demonstrated OPERABLE by performance of the following of augmented Specification 4.0.5. inservice inspection program in-lieu of the requirements i inspecu on - iypes in this specification, type of snubber shall mean snutbers t of the seteN design and manufacturer, irrespective of capa- .

b. VisualInspecthns Snubbers are categ d as inaccessible operation. -

ccessible during reactor-Eachofthese}re be_ inspected independently acco s (in e ible and accessible) may g to the schedule below. The first~

inservice visual inspection,o each .e of snubber shall be performed after 4 months but wit 40 months of dommencing POWER OPERATION'and=

shall= include all ers.- If all snubbers N eac OPERABLE duri efirstinservicevisual.inspNec'htypearefound inservice sual-ins , the second <

outa Otherwise, subsequent pection shallvisual be performed at the st refueling inspections shall be rformed accordance with the following schedule:

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GRAND GULF-UNIT 1 3/4 7-9 Amendment No.

9104170067 910410 PDR ADOCK 0"000416 p PDR

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ENL-91/09 P'LANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

o. of Inoperable Snubbers of Subsequent Visual h Type per Inspection Period Inspection Period *#

0 1

18 months i 25%

12 months 5%

2 6 mont i 25%

4 124 ys 1 25%

5, 7 days 1 25%

8 or re /31 days i 25%

. Visual Inspection Acceptance _riterip Visual inspections shall'verif cations of damage or impaired #yYat: (1) there are no visible indi-foundation or supporting ERABILITY and (2) attachments to the f4Icturear nctional, and (3) fasteners for attachment of the s er to the com nt and to the snubber anchorage are functi .

Snubbers which ahear inoperable as a result of visual' inspect s may be determined OPERA 6bE for the purpose of establishing ext visual inspection interval) rovided that:

(1) the causp f the rejection is clearly establish and remedied for that afticular snubber and for other snubbers irr ective of-type hat system that may be generically susceptible; affes d snubber is functionally tested in the as-found con d (2) the ion and d rmined OPERABLE per Specification 4.7.4.f. All snubbers co ected o an inoperable common hydraulic fluid reservoir shall be counte 4s inoperable snubbers.

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d. Transient Event inspection An inspection shall be performed of all hydraulic'and mechanical snub-bets attached to sections of systems that have experienced unexpected, potentially damaging transients, as determined from a review of opera-tional data or a visual inspection of the systems, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for i

accessible areas and within 6 months for inaccessible areas following-this determination. In addition to satisfying-the visual inspection

(; acceptance criteria, freedom-of-motion of mechanical snubbers shall be verified using at-least one of the following: (1)-manually induced snubber movement; or (2) evaluation of in place snubber piston setting;

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or (3) stroking the mechanical snubber through its full range of travel.-

ion interval for each type of snubber shall not be le ore i than one step unless a generic problem ha rected; in that event the n ified and cor-in e lengthened one step the first time and two steps th i able snubbers of that type are found.'

rovisions of Specification 4.0.2 are not applicable.

GRAND GULF-UNIT 1 3/4 7-10 Amendment No.

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-t . Attachment to GNRO-91/00060 NL- 91/09 pagoj of INSERT 1 D or 4.7.4): )

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

b. Visua1 Inspection Snubbers- are categorized as inaccessible or acconsible during reactor _ operation. Each of those categories (inaccessible and access.ible) may bo inspected independently according to the schedulo determined by Table 4,7.4-1. The visual inspection Interval for each typn of snubber shall be determined based upon thn criterla provided in Tabin 4.7.4-1 and the first inspection interval determined using this cr.iteria shall be based upon thn previous inspection interval as established by the requirements in effect before' Amendment _ .

c. Visual.Insp_ection Accepignce_ Criteria Visual inspection shall verify that (1) the'anubber has no visible ,

indications or_ damago or impaired OPERABiblTY, (2) attachmentn to i the foundation or supporting structure are functional, and (3)-fasteners for the attachment of the snubber to the component and to the snubbor anchorage are functional. Snubbers which appear .

Inoperabin as a result. of visual inspections shall be classiflod as i unacceptable and may be reclassiflod acceptablo.for thn purpose of established the next visual _ inspection interval, provided that J (1) the cause of_ the rejection is clearly established and remedied i' for that particular snubber and for other snubbers irrespectivo of type that may be genericall_y susceptible; and (2) the affected ,

snubber is functionally tested in thn_ as-found condition and l determined OPERABbE por Specification 4.7.4f. A review and -;

-ovaluation shall be performed:and documnnted to justify continund operation with an unacceptable _ snubber; If continued operation cannot bo justified, the snubber shall be-doclared inoperabin and.-

t.be ACTION requiremonta shall be met.

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Attachment to GNRO-91/00060 NL 91/09:

Page 2 of INSERT 1._(for 4.7.4):

TABLE 4.7.4-1 SNUDBER VISUAL, INSPECTION INTERVAL NUMBER OF UNACCEPTABLE SNUBBERS _

Population Column A Column B Column 0 or Category- Extend Interval Repeat Interval Reduced Interval

[No,t_es 1 and_21 [ Notes 3 and _6) ( Notes 4 and 61

__ (Notes 5 and 6)_

1 0 0 1 80 0 0 .2 100 0 3 4 1.

1150- 0 -3 8 200 2 5 13 300 5 12 25 400 -8 18 36

-500- 12 -48 '

-~ 750 - 20 '78

1000 or greator 29 56l 109-Noto it- The next. visualf inspection interval for a anubber population 'or-category sizo shall be determined basod upon the previous

inspection interval and the number of unacceptablo snubbors

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found during that interval.- Snubbers may be categorized, based

.upon their' accessibility during power' operation, as' accessible

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or inaccessible. Those categorlon may.be examined separately-

.or jointly, llowever,- that_ docialon..must -bo mado and documented before any: Inspection and that decision shall be used as tho

_ basis upon which to dotormine the next inspection-Interval for-that- category.

Noto 2: Interpolation betwoon. population or category sizes and.the

. number of. unacceptable snubbers is permissible. Uso next lower integer for the value of the limit for Column-A,-B,'or C if that integer includes a fractional value of unacuoptable snubbors as determined by Interpolation.

G9104011/SNLICFLR - 9

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, Attachment ta GNRO-91/00060 Nh-91/09 page 3 o f INSERT l_(for_4. 7.,4):

TABl.E 4. 7.4- 1 (cont . )

SNUBBER VISUAL, INSPECTION INTERVAL 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 twice the previous interval but not greater than 48 months.

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

Note 5: If the number of unacceptable snubbers is equal to or greater than the number in Column C. tha next inspection int erva1 sha11 he two-thirds of the previous interval.

Ilowever, if the number of unacceptable snubbers is less than the number in Column C but greater than the number in Column B, the next interval shall be reduced proportionally by interpolation, that is, the previous interval shall be reduced by a factcr that is one-third of the ratio of the dif ference between the i. umber of unacceptable snubbers found during the prev.lous interval and the number in Column B to the difference in the numbers in Columns B and C.

Note 6: The provisions of specification 4.0.2 are applicable f or all inspection intervals up to anel including 48 months.

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NL .91/ 09 PLANT SYSTEMS BASES 3/4.7.3 REACTOR CORE ISOLATION COOLING SYSTEM (Continued system The will surveillance be OPERABLErequirements when required. provide adequate assurance that the RCIC Although all active components are operation, a complete functional test requires reactor shutd The pump cooling at the earliest possible moment. discharge piping is maintaine 3/4.7.4 SNUB 8ERS All snubbers are required OPERABLE to ensure that the structural integ of the reactor coolant system and all other safety-related systems is maintaine during and following a seismic or other event initiating dynamic loads.

size. Snubbers are classified and grouped by design and manufacturer but not For example, mechanical snubbers utilizing the same design features of the 2-kip,10-kip, same type. and 100-ktp capacity manufactured by Companyare "A" of the The same design mechanical snubbers manufactured by Company "B" for the purposes of this fechnical Specification would be of a different as would hydraulic snubbers from either manufacturer. ,

type tion, size and system af fected shall be available at the pl with Section 50.71(c) of 10 CFR Part 50.

shall be determined and approved by the Plant Safety Review The Committee.T determination shall be based upon the existing radiation levels and the expected time to perform a visual inspection in each snubber location as well as other atmosphere, location, etc.), and the recommendations of and 8,10.

be made in accordance with Section 50.59 of 10 CFR Part 50.The XofThe sn visual inspection frequency is based upon maintaining a constant le V protection.

inversely w Therefore, the required inspection interval va by the number ofhe observed snubber failures for a given type an determined rable snubbers found during an inspe of each type.

In order to establish t'he Q spection frequency for e ype of snubber, it was assumed that the frequency'$f snubber fail e d nd initiating events is constant with time and that the f ha re y snubber on that system could cause the system to be unprotected initiating event. Inspectioits erformedto'res beforeit in failure during an assumed be used as a new refer joint to determine the next'4n. ection. hat interval has elapsed i

However, l the results of ys early inspections performed before the time inteyr Mas elapsed (nominal time less 25%) may not be useinal required lengthen thepqtTf red inspection interval.

A rter inspection interval will override the previous schedule.Any inspect l

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GRAND GULF-UNIT 1 B 3/4 7-2 Amendment No. -

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Ep 91 y.09 - ,

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, #LANT-SYSTEMS BASES 3/4.7.4 SNUBBER $(Continued)

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-inepe ele-and ee!' ^^t M detem!"ed OPEH'Lvia fen:ti:::1 t ; ting.

To provide assurance of snubber func.tional reliability one of two functional testing methods is used with the stated acceptance criteria:

. 1.

Functionally test 10% of a type of snubber with an additional 5%

tested for each functional testing failure, or 2.

Functionally test a sample size and determine sample acceptance using Figure 4.7.4 1.

, Figure 4.7.4-1 was developed using "Wald's Sequential Probability Ratio

> Plan" described in;" Quality Control and Industrial Statistics" by Acheson J. Duncan and the Revision 2 draf t (9/86) of the ANSI /ASME OM4 document (Examination and Performance Testing of Nuclear Power Plant Dynamic Restraints (Snubbers).

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Persanent or other exemptions from the surveillance program for individual- 1

. snubbers may.be granted by the Commission if a justifiable basis for exemption j is presented and, if applicable, _ snubber life destructive testing-was performed

.to qualify-the snubbers for the applicable design conditions at either the completion of their fabrication or at a subsequent date.- Snubbers so exempted )

_j shall be -listed in the list of individual snubbers indicating the extent of the= exemptions.

The service life of a snubber is established via manufacturer input-and information through consideration of- the snubber service conc'itions and asso-ciated installation and maintenance records (newly installed.si.obber, seal l replaced. spring replaced,-in high radiation. area in high temperature area, L etc.). ~ The requirement to monitor the snubber ser,vice life is in '

of their age and operating conditions. -These records will provide-statistical bases for future consideration of snubber service life.

3/4.7.5 SEALED $0VRCE CONTAMINATION The limitation on removable contamination for sources requiring-leak testing, including alpha esitters, is based on 10 CFR 70.39(c) limits for plutonium. This liettation will ensure that' leakage free byproduct, source

• and special nuclear material- sources will not exceed alloweble-intake values,.

Sealed sources are classified into three groups according to their use, with-surveillance requirements commensurate with tw probabil' ty of damage to a source in that group. Those sources which are frequently handled are required to be tested more often-than those which are not. Sealed sources-which are-continuously enclosed within a shielded mechanism, i.e., sealed sources within radiation monitoring or boron measuring devices, are considered to be stored and .

need not be tested unless they are removed from the-shielded sechantsa.

GRAND GULF-UNIT 1 8 3/4 7'3 Amendment No. M, 56, ,

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_ .I_NSERT 2__( for Bases 3_L4. 7._4.):  !

y Visual inspeEtion requirements are based on the guidanco provided in Generic-Lotter.90-09 dated December 11, 1990. A visual inspection is the obnorvation of the condition of installed snubbers _ to identify those that are damaged, degraded, or inoperable as caused by physical means,

-loakage, corrosion, or environmental exposure. The functional testing program providos a 95 porcent confidence level that 90 to 100_ percent of i the snubbers will operate within the speciflod acceptanco limits. The  !

performance of visual examinattons is a separato process _that complements -- r the functional testing program and providos addit.ional confidence in snubber operability.

The visual inspection schedule (as datorminod-by Table 4.7.4-1) is based on tho _ number of unaccept.able snubbers found during the previous

inspection in proport.lon to the sizes of tho'various snubber populations or categories. A snubbor is considered-unacceptable if it fails the accept.anco criteria of the. visual inspection. The inspection interval is based on a- fuel cycle of-up to 24 months and may be as long as two cyclos, or'48 months for other fuol cycles, depending on the number of unacceptable snubbers found during tho provlous visuni inspection.

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