ML19210A752
| ML19210A752 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/08/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19210A746 | List: |
| References | |
| NUDOCS 7910310565 | |
| Download: ML19210A752 (5) | |
Text
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110. DEL TEC1011 CAL SPECIFICAT10NS SURVEILLUCE FEOUIREMENT 1.1.4ITINC CONDITION FOR OPERATION 3.6.I Hydraulic Snubbers
,, ', 4.6.I Hydraulic Snubbers 1.
During all modes of operation The following surycillacce requirenent:
execpt Cold Shutdown and Refuel, apply to all hydraulic snubbers except all hydraulic snubbers shall be those listed in 3.6.I.2.
operable except as noted in 3.6.I.2 through 3.6.I.5 below.
1.
All hydraulic snubbcrs whose scal material has been dc onstrated by 2.
The hydraulic snubbers listed.
operating experienec, lab testing in Table 3.6.I are not required or analysis to be cc patibic coolant with the operating environ = cat to protect the primary,fety verify their operability in shall be visually i..spected to system or any other sa related systcc or component and are therefore exc pt from accordance with the following schedulo:
these specifications.
3.
From and after the time that
' Number of Snubbers Next Required a hydraulic snubber is determined Found Inoperable In:pection to be inoperable, continued During Inspection Interval zeactor operation is permissible or During Inspection only during the succeeding 72 Interval hours unless the snubber is sooner made operable.
0 18 months + 254 1
12 conths + 25%
2 6 months 7 25%
4.
If the requirements of 1
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and 3.6.I.3 cannot be met. a 3,4 124 days 25%
orderly shutdown shall be initiated 5,6,7 62 days
+ 23%
and the reactor shall be in a
>8 31 days 2 5 *.
cold shutdown condition within 36' hours.
The required insper.icn interval shall not be icngthened :: ore than 5.
If a hydraulic snubber is determined one step at a' time.
to be inoperable while the reactor is in the shutdown or refuel raode, Snubbers may be catqsrited in the snubber shall be cade operable two groups, "accesi Jal " or
" inaccessible" baseu on their prior to reactor startup.
accessibility for...s?cetion during reactor oper.: tion.
These two groups na; be inspected independently according to the above schedule.
2.
All hydraulic snubbers whose saal materials have not acen demonstrated to 'ce cenpatible with the operating environment shall be visually inspected for operability eve:y 31 days.
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m er SURhEILI.ANCE REOUIRE.\\EST
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LIMITINC CONDITION FOR OPERATION 4.6.I Hydraulic Snubbers (cont'd) 3.
The initial inspection shall be
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perforr.cd within 6 conths from the date of issuance of these specifi-For t o purpose of entering k
cations.
the schedule in Specification 4.6.I.1, it shall be assuned that the facility had been on a 6 month CD h0 0g t b
inspection interval.
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&1 4.
Once each refueling cycle, a repre-sentative sampic of 10 snubbers or approximately 10% of the snubbers, whichever is Icss, shall be functionally tested for operability including verification of proper piston movement, Icek up and bleed.
For each' unit and subsequent unit found inoper:bic, an additional 10% or ten snubbers sht"1 be so tested until no = ore failures are found or all units have been tested.
S.
Once cach refueling cycle at Icas:
two representative snuYaers fro:
a relatively severe e..v;ror. dent shall be completely disasse:. bled and examined r,or damage and abnormal seal degradation.
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.. i TABLE 3.6.I Identification No.
Location
_ Elevation
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BASES:
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{0 3.6.I and 4.6.I O
Hydraulic Snubbers Snubbers are designed to prevent unrestrained pipe notion under dynamic loads as might occur during an carthquake or severe transient, while allowing no mal thersal action during star up and shutdown. The consequence of an inoperable snubber is an increase in the probability of structural da: age to piping as a result of a seismic or other event initiating dynamic loads.
It is therefore required that all hydraulic snubbers required to protect the pri=ary coolant systen or any other safety system or co=ponent be operable during reactor operation.
Because the snubber protection is required only during relatively low probability events, a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed for repairs or replacements.
In case a shutdown is recuired, the allowance of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to reach a cold hutdown condition will pcmit 'an orderly shutdcwn censisten: with standard ope. rating procedures.
Since plant startup should not ce=cace with knowingly defective safety related equip =ent, Specification 3.6.I.5 prohibits startup with inoperabic snubbers.
All safety related hydraulic snubbers are visually inspected for overall integrity and operability.
The inspection will include verification of proper orientation,
' adequate hydraulic fluid 1cyc1 and proper attachment"of snubber to pioing and structures.
The inspection frcouency is based upon maintaining a constant 1cyc1 of snubber protection. Thus the required inspection in:crvoi varies inversely with the observed snubber failures.
The number of inoperabic snubbers found during a required ins;cction detemines the time interval for the next required inspection.
Inspectior.s peric=ed before that interval has clapsed may be used as a new reference point to dc: ermine the next inspection. However, the results of such c.rly inspections pericr_.cd before the original required time interval has elapsed (no: nal time less 25',) may not be used to lengthen the required inspection interval. Any inspection whese results require a shorter inspection interval will override the previous schedule.
Experience at operating facilitier has shown that the required surveillance program should assure an acceptabic level of snubber perfor=.nce provided that the seal materials are cc=patibic with the operating environment.
Snubbers containing seal material which has not been de onstrated by operating -
experience, lab tests or analysis to be co=patibic with the operating envircn=ent should be inspected more frequently (every month) until material compstability is confi med or an appropriate changecut is co=pleted.
Exa=ination of defcetive snubbers at reactor facilitics anc nterial tests perfor=ed at several laboratories (Reference 1) has shown that cillable gum polyuretht.no deteriorates rapidly under the to:perature and toisture conditions present in many snubber locations.
Although colded polyurethane exhibits greater resistance to these conditions, it a-1so may be unsuitable for application in the higher temperature environments.
Data are not currently available to precisely defino an upper temperature li=it for the colded polyurethane.
1.ab tests and in-plant
.cxperience indicate that seal materials are availabic, primarily ethylene propylene 1.493 273.
t BASES:
3.6.1 and 4.6.1 Hydraulic Snubbers (cont'd) co podads,,chich should give satisfactory performance under the mos' severe cond expected,in rrretor installations.
To further increase the assurance of snubber reliability, functional tests should I
These tests will include streking of the be perforced once each refueling cycle.
lock-up...ad biced. Ten percent or snubbers ltoverifyproperpiston=ove:ent, ten snubbers, whichever is Icss, represe Observed failures on these sa ples should require testing of additional units.
Snubbers in high radiation areas or those especially difficult to rc=ove need not be selected for functional tests provided operability was previously verified.
To co:pic:ent the visual external inspections, disasse=bly and internal ex.mination for componcat damage and abnor=al seal degradation should be performed.
The examination of two units, each refueling cycle, selected from relatively sctere Any observed wear, breakdo..n environ.4ents should adequately serve this purpose.
or deterioration will provide a basis for additional inspections.
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.e Report H. R. Erickson, Bergen Paterson to K. R. Coller, N'RC, October 7, 1974 (1)
Subject:
Hydraulic Shock Sway Arrestors 1493 274 o
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