ML20247Q256

Proposed Tech Specs Re Functional Test Program for Snubbers

ML20247Q256
Person / Time
Site:	Davis Besse
Issue date:	05/26/1989
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20247Q241	List: ML20247Q234 ML20247Q256
References
NUDOCS 8906060371
Download: ML20247Q256 (7)

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Doc,ket Number 50-346 i License humber NPF-3 1 a mn Page 1 PLANT SYSTEMS 3/4.7.7 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.7 All s .cy-related snubbers shall be OPERABLE.

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

ACTION:

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a. With one or more snubbers inoperable: 1. 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, or 2. verify system operability with the snubber (s) inoperable by engineering evaluation within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; or 3. declare the supported subsystem inoperable and follow the appropriate ACTION statement for that system.

and, for snubbers which have failed either the visual or functional test:

b. Perform an engineering evaluation within 90 days to determine if any safety-related system or component has been adve.rsely affected by the inoperability of the j snubber and if the snubber mode of failure has imparted a -l significant effect or degradation on the supported component or system.1 The provisions of Technical Specification 3.0.4 are not applicable for the component or system.

SURVEILLANCE REQUIREMENTS 4.7.7 Each snubber 2 shall be demonstrated OPERABLE by the requirements of the following surveillance programs and pursuant to requirements of Specification 4.0.5.

4.7.7.1 Visual Inspection Program 1

Engineering evaluation is not. required when a snubber is removed- for surveillance testing provided it is returned to OPERABLE status within the requirements of action statement a.

2 Safety-related snubbers are listed in the latest revision of applicable surveillance test procedure (s). Snubbers may be added to, or removed from, safety-related systems and their assigned groups without a License Amendment.

l DAVIS-BESSE, UNIT 1 3/4 7-20 Amendment No. W , 111 8906060371 890526 PDR ADOCK G5000346

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Docket Number 50-346 Lic'ensd Wumber V4PF-3 Seria?. Number 1646 Attachment 3 Page 2 PI. ANT SYSTEMS Si.5VEILI.ANCE REQUIREMENTS (Continued) 4.7.7.2 Functional Test Program 54 l l

a. General Requirements At least once per inspection interval a representative sample of each group of snubber in use in the Plant shall -

be functionally tested in accordance with Specifications 4.7.7.2.b and 4.7.7.2.c. Response to the failures shall be in accordance with Specification 4.7.7.2.d.

For all snubbers, functional testing shall consist of either bench testing or in place testing.

b. Inspection Interval and Sample Criteria The snubbers may be categorized into groups based on physical characteristics. Snubbers are divided into four j (4) groups: " Accessible" - Group 1 and " Inaccessible" -

Group II for either hydraulic or mechanical. Each group may be tested independently from the standpoint of performing additional tests if failures are discovered.

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DAVIS-BESSE, UNIT 1 3/4 7-22a Amendment No.lll (Next Page is 3/4 7-23)

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' Docket. Number 50-346 Licens*e Number NPF-3 Serial Number 1646 Attachment 3

1. E" PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

INbEST [The__.u. inspection inter el for functional testing shall be -t9-

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--- A perfor'med al feast once cyery So months.

Snubbers which are scheduled for removal for seal maintenance may be included in the test sample prior to__  ;

any maintenance on the snubber. r .~ '

he vezed ac.corde.n3 $'0 OC The representative sample shall ::::::: :f t 1..;10 'et"4dI#"

(rounded off to next highest integer) each - sho4*>M group of snubbers in use in the Plant. The selection c6e ve process shall ensure that all snubbers, regardless of their accessibility classification, are functionally for tested at least once every

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c. Acceptance Criteria For hydraulic snubbers (either inplace testing or bench testing), the test shall verify that:

1. Snubber piston vill allow the hydraulic fluid to

" bypass" from one side of the piston to the other to assure unrestrained action is achieved within the specified range of velocity or acceleration in both tension and compression.

2. When the snubber is subjected to a movement which creates a load condition that exceeds the specified range of velocity or acceleration, the hydraulic fluid is trapped in one end of the snubber causing suppression of that movement.

3. Snubber release rate or bleed rate, where required, occurs in compression and tension.

For mechanical snubber in place and bench testing, the test simil verify that:

1. The force that initiates free movement of the snubber rod in either tension or compression is less than the specified maximum drag force.

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

DAVIS-BESSE, UNIT 1 3/4 7-23 Amendment No. 53,94 111

Docket Nuniber 50-346 License Eumber NPF-3 Serial

• Number 1646 Attachment 3 Page 4 INSERT A 1

l To provide assurance of snubber reliability, a representative sample of the installed snubbers shall be functionally tested at least every 30 calendar months according to the expression S - (X/180) times 100%, where "X" is the time period between inspections, in months or partial months, rounded to the higher value and "S" is the initial sample size, in percent. "S" is required l to be greater than or equal to 10 percent even if "X" is less than or equal to 18 months.

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! Docket Number 50-346 -

LLicense Number WPF-3 4 .

,1-: Serial

• Number'1646:

Attachment 3-Page 5 ,

PIANT SYSTEMS-BASES PIANT SYSTEMS.

~3/4.7.7 SNUBBERS BASES All safety-related snubbers are required OPERABI.E to ensure that' the >

structural integrity of the reactor coolant system and all other safety--

related-systems is asintained during and following a dynamic event.

Snubbers excluded from this inspection program are those installed on safety-related systems.for loads other than' dynamic or on nonsafety-related.and then only if their failure or failure of the system on which

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p they are installed, would have no adverse effect on any safety-related systen-during a dynamic event.

Inoperable'is defined as:

1. For visual-test

a. -The fluid no longer is supplied to the valve block, or

b. Mounting pins are disengaged from the snubber.

c. Attachment to foundation or supporting structure is not secure.

2. For functional test

s. The snubber (excluding end anchors, i.e., pin-to-pin) does not meet specified test criteria.

The visual inspection frequency is based upon maintaining a constant level of snubber protection to systems. Therefore, the required inspection interval varies inversely with the observed snubber failures and is determined by the number of inoperable snubbers found during an inspec-tion. Inspections performed before that interval has elapsed may be used as a new reference point to determine the next inspection. However, the results of such early inspections performed before the original required time interval has elapsed (nominal time less 25).) may not be used to lengthen the required inspection interval. Any inspection whose results require a shorter inspection interval will override the previous schedule.

When the cause of the" refection of a snubber is clearly established and' remedied for that snubber and for'any other snubbers that any be generi-cally susceptible, and verified by functional testing, that snubber may be exempted from being counted as inoperable. Generically susceptible snubbers are those which are of a specific make or model and have the same design features directly related to rejection of the snubber by visual inspection, or are similarly located or exposed to the same environmental conditions such as temperature, radiation, and vibration.

DAVIS-BESSE, UNIT 1 B 3/4 7-5 Amendment No. 94/,111

Docket Number 50- 346

License Number WPF-3 l' s Sefial* Number 1646 L Attachment 3 Page 6 l PLANT' SYSTEMS l-BASES When a snubber is found inoperable through a visual or functional test, an engineering evaluation is performed, in' addition to.the determination of the snubber mode of failure, in order to determine if any safety-related component or system has been adversely affected by the inoperability of the snubber. The engineering evaluation shall determine whether or not the snubber mode of failure has imparted a significant effect or degrada-tion on tbe supported component or system.

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To provide assurance of snubber functional reliability, a representative sample of the installed snubbers will be functionally tested at M x x 2 i:::r;:h . Observed failures of these sample snubbers shall require functional testing of additional units. When a snubber is found to be inoperable due to failure to lock up or failure to move (i.e., frozen in place), the cause will be evaluated for further action or testing.

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In cases where the cause of failure has been identified, additional snubbers that have a high probability for the same type of failure or are l

being 1 sed in the same application that caused the failure shall be tested. This requirement increases the probability of locating inoperable snubbers without testing 100% of the snubbers.

Hydraulic snubbers and mechanical snubbers may each be treated as a different entity for the above surveillance programs.

4 DAVIS-BESSE, UNIT 1 B 3/4 7-5a Amendment No. 94

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p Dockot Nurbar 50-346

, ,, hiernsa Number NPF-3 Striel Numb 2r 1646  ;

Attachment 3 {

Page 7 J INSERT B The initial sample size, determined by the equations S - (X/180) times 100%,

where "X" is the time period between inspections, in months or partial months, rounded to the higher value and "S" is the initial sample size, in percent, vill ensure that all snubbers vill be tested at least once every 15 calendar years.

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