ML20012F345

Proposed Tech Specs Re Limiting Condition for Operation & Surveillance Requirements for Visual Insp of Snubbers

ML20012F345
Person / Time
Site:	Fermi
Issue date:	03/26/1990
From:	DETROIT EDISON CO.
To:
Shared Package
ML20012F344	List: ML20012F345 NRC-90-0057, Application for Amend to License NPF-43,revising Tech Spec 3/4.7.5 to Extend Visual Insp of Snubbers Until Second Refueling Outage Currently Scheduled for Mar 1991
References
NUDOCS 9004110188
Download: ML20012F345 (3)

Text

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PLANT SYSTEMS llIFORI4ATl0!I0!ILY 3/4.7.5 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.5 All* hydraulic and mechanical snubbers shall be OPERABLE.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3. OPERATIONAL CONDITIONS 4 >

and 5 for snubbers located on systems required OPERABLE in those OPERATIONAL CONDITIONS.

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 4.7.5g. on the attached component or declare the attached system inoperable and follow the appropriate ACTION statement for that system.

SURVEILLANCE REQUIREMENTS 4.7.5 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program in addition to 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 l

reactor operation. Each of these groups (inaccessible and acces-i sible) 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 during the first inservice visual inspection, the [

second inservice visual inspection of that system shall be performed I at the first refueling outage. Otherwise, subsequent visual inspec-tions of a given system shall be performed in accordance with the following schedule:

• As described in the bases.

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9004110168 900326 '

PDR ADOCK 05000341 P PDC

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l PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

No. of Inoperable Snubbers of Each Type Subsequent Visual on Any System per Inspection Period Inspection Period *#

0 18 months 1 25%

1 12 months 1 25%

2 6. months 1 25%

3,4 124 days t 25%

5,6,7 62 days t 25%

8 or more 31 days t 25%

c. Visual Inspection Acceptance Criteria Visual inspections shall verify that: (1) there are no visible indications of damage or impaired OPERABILITY and (2) attachments to the foundation or supporting structure are secure, and (3) fasteners for attachment of the snubber to the component and to the snubber anchorage are secure. Snubbers which appear inoperable as a result of visual inspections may be determined OPERABLE for the purpose of I establishing the next visual inspection interval, provided that:

(1) the cause of the rejection is clearly established and remedied ot-for that particular snubber and for other snubbers irrespect of ]

type on that system that may be generically susceptible; and 2) the affected snubber is functionally tested in the as-found condition and determined OPERABLE per Specifications 4.7.5f. For those snubbers common to more than one system, the OPERABILITY of such snubbers shall be considered in assessing the sur,veillance schedule for each of the related systems,

d. Transient Event Inspection An inspection shall be performed of all hydraulic and mechanical j l snubbers attached to sections of systems that have experienced l

unexpected, potentially damaging transients as determined from a l

review of operational data and a visual inspection of the systems l within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for accessible areas and 6 months for inaccessible ~j areas follcwing such an event. In addition to satisfying the visual i 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; or (3) stroking the mechanical snubber through 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 lengthened one step the first time and two steps thereafter if no inoperable l snubbers of that type are found on that system.

1. The provisions of Specification 4.0.2 are not applicable.

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PLANT SYSTEMS BASES i

SNVBBERS (Continued) to be unprotected and to result in failure during an assumed initiating event.

Inspections performed before the interval has elapsed may be used as a new refer-ence 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.

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 functional testing methods is used with the stated acceptance criteria: $%

1. Functionally test 10% of a type of snubber with an additional tested for each functional testing failure, or

2. Functionally test a sample size and determine sample acceptance or rejection using Figure 4.7.5-1, or

3. Functionally test a representative sample size and determine sample acceptance or rejection using the stated eque. tion.

Figure 4.7.5-1 was developed using "Wald's Sequential Probability Ratio Plan" as described in " Quality Control and Industrial Statistics" by Acheson J. Duncan.

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 destructive testing was performed to qualify the snubbers for the applicable design conditions at either the I completion of their fabrication or at a subsequent date. Snubbers so exempted 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 conditions and asso-ciated installation and maintenance records (newly installed snubber, seal i

relaced, spring replaced, in high radiation area, in high temperature area, l et.c. ) The requirement to monitor the snubber service life is included to ensure that the snubbers periodically undergo a performance evaluation in view of their age and cperating conditions. These records will provide statistical bases for future consideration of snubber service life.

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