ML20215G868

Proposed Tech Specs,Allowing Performance of Snubber Surveillance for Second Fuel Cycle to Correspond to Scheduled Second Refueling

ML20215G868
Person / Time
Site:	LaSalle
Issue date:	06/16/1987
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20215G837	List: ML20215G833 ML20215G868
References
3212K, NUDOCS 8706230417
Download: ML20215G868 (4)

Text

ATTACHMENT C TECHNICAL SPECIFICATION CHANGE REQUEST LASALLE COUNTY STATION UNIT 1 NPF-11 REVISED SECTION 3/4.7.9 page 3/4 7-28 l

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B706230417 670616 PDR ADDCK 05000373 P PDR

• PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

c. Visual Inspection Acceptance Criteria -

Visual inspections shall verify that: 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 establishing the next visual inspection interval, provided that: (1) the cause of the rejec- I tion is clearly established and remedied for that particular snubber and for other snubbers irrespective of type on that system that may l be generically susceptible; and (2) the affected snubber is fenctionally tested in the as-found condition and determined OPERABLE per Specifica-tion 4.7.9f. All snubbers connected to an inoperable common hydraulic fluid reservoir shall be counted as inoperable snubbers. For those snubbers common to more than one system, the OPERABILITY of such snubbers shall be considered in assessing the surveillance schedule for each of the related systems. -

d. Transient Event Inspection An inspection shall be performed of all hydralic and mechanical snubbers attached to sections of systems that have experienced unexpected, potentially damaging transients as determined from a ,

review of operational data and a visual inspection of the systems within 6 months following such an event. 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; or (3) stroking the mechanical snubber through its full range of travel.

e. Functional Tests g During the first refueling shutdown and at least once per 18 months thereafter 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 changed during the test period. The NRC Regional Administrator shall be notified in writing of the sample plan selected prior to the test period or i 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 i 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 Specification 4.7.9f. , an additional 10%

of that type of snubber shall be functionally tested until no 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 Y 'The Second Onchomal fesf seveillance skall be conducftd /8moof4g froM 04 commencemenf ohower ejaardio6 [or- CYc/t 2.

• LA SALLE - UNIT 1 3/4 7-28 Amendment No.18 v, . . ..

ATTACHMENT D SIGNIFICANT HAZARDS CONSIDERATION Commonwealth Edison has evaluated the proposed Technical Specification amendment, and determined that it does not represent a significant hazards consideration. Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92, operation of LaSalle County Station  ;

Unit 1 (LSCS-1)'in becordance with the proposed amendment will not: )i

1) Involve a significant increase in the probability or consequence of an f accident previously evaluated because their still exists a high level of  !

snubber protection for safety related piping systems, against. postulated dynamic loads and load combinations given in Section 3.9 of the UFSAR.

All safety related snubbers in LSCS-1 were functionally tested at the first refueling outage. Test failures were evaluated for their impact on system piping, and corrective actions were taken to prevent their recurrence. The snubber population was therefore fully operable at the start of the second LSCS-1 fuel cycle, providing maximum protection to plant piping against postulated events as defined in Section 3.9 of the UPSAR. The snubber population will undergo regularly scheduled visual inspections during the second fuel cycle, to provide a high level of assurance that the units are in good mechanical condition, and have not been damaged by unanticipated service conditions not postulated in the UFSAR, such as a system water hammer due to an improper system lineup.

2) Create a possibility of a new or different kind of accident from any accident previously evaluated because the proposed amendment merely extends the time interval between snubber surveillances, and does not  ;

change the testing requirements or acceptance limits for insuring snubber operability over plant' life. Snubbers which fail the upcoming test at second refuel will still be evaluated as before for their impact on the structural integrity of associated system piping, using the design loads and acceptance limits specified in Chapter 3.0 of the UFSAR.

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3) Involve a significant reduction in the margin of safety as defined in the bases of Technical Specification 3/4.7.9. The complete test of the LSCS-1 snubber population at first refueling restored the population to the same level of operability as it had prior to the first cycle. The Technical Specification does not place a time limit on the first cycle for.when snubber testing must occur, but merely requires it to be done at first refueling. In addition, the plant remained in cold shutdown for approximately four months following the first refuel snubber surveillance. This was a period of greatly reduced potential for snubbers to fail, since the pipe vibratory and transient loads and plant environmental conditions which are known to degrade snubbers are absent, because plant systems are generally shutdown and out of service for maintenance. Therefore, the additional four months of snubber service being added to the current surveillance period during reactor operation, is offset by an equal time period of no snubber degradation at the beginning of the surveillance period. Finally, the mechanical snubbers used exclusively on LUCS-1 display a tendency to fail by becoming harder to stroke or by becoming. rigid, when degradation of the units occur in service. The snubbers still serve to prevent excessive pipe accelerations and displacement in this condition. Therefore, the structural integrity of plant piping can be expected to be maintained during design basis dynamic events, as specified in the bases of Technical Specification 3/4.7.9.

Based on the preceeding discussion, it is concluded that the proposed Technical Specification amendment clearly falls within all acceptable criteria with respect to plant piping systems and support components, the consequences of previously evaluated accidents will not be increased, and the margin of safety will not be decreased. Therefore, based on the guidance provided in l the Federal Register and the criteria established in 10 CFR 50.92 (e), the  ;

proposed change does not constitute a significant hazards consideration, j 1

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