ML17278B138
| ML17278B138 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/12/1986 |
| From: | WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | |
| Shared Package | |
| ML17278B137 | List: |
| References | |
| TAC-64217, NUDOCS 8612190200 | |
| Download: ML17278B138 (5) | |
Text
'LANT SYSTEMS 3/4. 7. 4 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.4 All'ydraulic and mechanical snubbers shall be OPERABLE.
APPLICABILITY:
OPERATIONAL CONDITIONS 1, 2, and 3.
OPERATIONAL CONDITIONS 4 CDNDITIDNgj('(SEC N sD-,P Q) ~
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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 4.7.4g on the attached component or declare the attached system inoperable and follow the appropIiate ACTION statement for that system.
~b SURVEILLANCE REOUIREMEHTS 4.7.4 Each snubber shall be demons r OPERABLE by performance of the following augmented inservice inspectstg program and the requirements of Specification 4.0.5.
a.
Insnection Tunes As used in this sp cation, type of snubber shall mean snubbers of the same desi d manufacturer, irrespective of capacity.
b.
Visual Inspections Snubbers are categorized as inaccessible or accessible during reactor operation.
Each of these groups (inaccessible and accessible) may be inspected independently according to.the schedule below.
The 'first inser vice 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 at the first refueling outage.
Otherwise, subsequent visual inspections of a given system shall be performed in accordance with the following schedule:
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PLANT SYSTEMS SURVEILLANCE RE UIREMEHTS Continued Ho. Inoperable Snubbers of Each Type on Any System er Insoection Period 0
1 2
3,4 5,6,7 8 or more c.
Visual Inspection Acce tance Criteria
'Subsequent Visual Ins ection Per'
¹ 18 months 4 25
-50'Fo 32 months R 2 ~
6 months
+ 25K 124 days i 25K 62 days ~ 25K 31 days
~ 25K Visual inspections shall verify that: (1) there are no visible indi-cations of damage or impaired OPERABILITY, (2) attachments to the foundation or~pporting structure are secure, and (3) fasteners for attachment the snubber to the component and to the snubber anchorage are e.
Snubbers which appear inoperable as a result of visual inspec opy may be determined OPERABLE for the purpose of establishing the r%p@visual inspection interval, provided that:
(1) the cause of thW ection is clearly established and remedied for that particular er and for other snubbers irrespective of type on that system th ay be generically susceptible; and (2) the affected snubber is fun ally tested in the as-found condition and determined OPERABLE per 5
fication 4.7.4f.
All snubbers connected to an inoperable common hy raulic fluid reservoir shall be counted as inoperable snubbers.
For thos~nubbers common to more than one
- system, the OPERABILITY of suds ubbers shall be considered in assessing the surveillance sche for each of the related systems.
d.
Transient Event Ins ection An inspection shall be performed'f all hydraulic 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.
"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 snubbers of that type are found on that system.
¹The provisions of Specification 4.0.2 are not applicable.
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PLANT SYSTEMS BASES 3/4.7.4 SNUBBERS All snubbers are required OPERABLE to ensure that the structural integrity of the Reactor Coolant System and all other safety"related systems is maintained during and following a seismic or other event initiating dynamic loads.
Snubbers excluded from this inspection program are those installed on nonsafety-related systems and then only if their failure or failure of the system'n which they are installed would have no adverse effect on any safety"related system.
Snubbers are classified and grouped by design and manufacturer but not by size.
For example, mechanical snubbers utilizing the same design features of the 2-kip, 10-kip, and 100-kip capacity manufactured by Company "A" are of the same type.
The same design mechanical snubbers manufactured by Company "B" for the purposes of this Technical Specification would be of a different type, as would hydraulic snubbers from eithe'r manufacturer~
A list of individual snubbers with detail nformation of snubber loca-tion and size and of system affected shall be lable at the plant".in,accord-ance with Section 50.71(c) of 10 CFR Part 50.
e accessibility, of each snubber shall be determined and approved by the Plant perations Committee.
The deter mination shall be based upon the existin diation levels and the expected time to perform a visual inspection in each er location as well as other factors associated with accessibility during operations (e. g., temperature, atmos"
- phere, location, etc. ), and the rec ations of Regulatory Guides
- 8. 8 and 8.10.
The addition or deletion of hydraulic or mechanical snubber shall be made in accordance with Section
. 'f 10 CFR Part 50.
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The visual inspection freg~y is based upon maintaining a constant level of snubber protection to eacQ~ty-related system.
Therefore, the required inspection interval varies i~sely with the observed snubber failures on a
given system and is determined by the number'of inoperable snubbers found during an inspection.
In order to establish the inspection frequency for each type of snubber on a safety-related system, it was assumed that the frequency of snubber failures and initiating events is -constant with time and that the failure of any snubber on that system could cause the system to be unprotected and to result in failure during an assumed initiating event.
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.
The acceptance criteria are to be used in the visual inspection to deter mine 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 are used with the stated acceptance criteria:
1.
Functionally test 10@ of a type of snubber with an additional 1N tested for each functional testing failure, or 2.
Functionally test a sample size and determine sample acceptance or rejection using Figure 4.7-1, or WASHINGTON NUCLEAR - UNIT 2 B 3/4 7-2