ML17279A660
| ML17279A660 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/01/1987 |
| From: | WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | |
| Shared Package | |
| ML17279A659 | List: |
| References | |
| TAC-66808, NUDOCS 8712080154 | |
| Download: ML17279A660 (12) | |
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ATTACHMENT 2 CONTROLLED COPY Page 1 of 7 PLANT SYSTEMS SURVEILLANCE RE UIREMENTS Continued e.
Functional Tests 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 the sample plan used in the prior test period shall be implemented:
At least 10~ of the total of each type of snubber shall be 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.af.,
an additional ~ 5'/e 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 3'7 tionally tested in accordance with Figure 4.7-1.
"C" is the total number of snubbers a~~pe.found not meeting the accep-tance requirements of Specification 4.7.4f, The cumulative number of snubbers ef '~pe-tested is denoted by "N". At~e-mn I
e f 'l II ubb 1
terminated.
When the point plotted lies in the "Continue tested until the point falls in the Accept" region er-@he tested.
Testing equipment failure during functional testing may invalidate that day's testing and allow that day's testing to resume anew at a later time provided all snubbers tested with the failed equipment during the day of equipment failure are retestedy ~
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An initial representative sample of 55 sn 'ers shall be f
functionally tested.
For each snubber type ich does not meet t
functional test ac tance criteria, anoth sample of at lea one"half the size the initial sample sh 1 be tested until e to al number tes d is equal to the inits 1 sample size mult'lied by the facto
+ C/2, where "C" is t number of snubbers und which do not et the functional test ccept" ance criteria.
he results from is sample plan shall b
plotted using an cept" line whic follows the equa ion N = 55(1
+ C/2).
Ea snubber point uld be plotted as soo WASHINGTON NUCLEAR - UNIT 2 3/4 7-12 S712080i54 5000397 S7i2
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Page 2 of 7 PLANT SYSTEMS SURVEILLANCE RE UIREMENTS Continued) e.
Functional Tests (Continued) aa the snubbe~is tested.
If t e point plotted lls on or below the "Accept" line, testing that type of sn bber may be terminated.
If thq int plotted fa s above the "Accept" line, testing must con ue until the p iqt falls in the ~
"Accept" region or all the ubbers of tha&type have been tested.
The representative sample selected for the functional test sample plans shall be randomly selected from the snubbers of each type and reviewed before beginning the testing.
The review shall ensure, as far as practicable, that they are representative of the various con-figurations, operating environments, range of size, and capacity of snubbers of each type.
Snubbers placed in the same location as snubbers which failed the previous functional test shall be retested at the time of the next functional test but shall not be included in the sample plan.
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- sng, addst>on samp ng 1s requ'd due to ailure of nly one t e of snu er, the fun ional test results sh 11 be revip ed at tha time to etermine if additional amples shq ld be limyted to the ype of s bber which g s failed tp functionpl testing.
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Functional Test Acce tance Criteria
$88'ssr T A
The snubber functional test shall verify that:
1)
Activation (restraining action) is achieved within the specified range in both tension and compression; 2)
Snubber bleed, or release rate where required, is present in both tension and compression, within the specified range; 3)
Where required, the force required to initiate or maintain motion of the snubber is within the. specified range in both directions of travel; and 4)
For snubbers specifically required not to displace under continuous
- load, the ability of the snubber to withstand load without displacement.
Testing methods may be used to measure parameters indirectly or para-meters other than those specified if those results can be correlated to the specified parameters through established methods.
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Functional Test Failure Anal sis An engineering evaluation shall be made of each failure to meet the functional test acceptance criteria to determine the cause of the failure.
The results of this evalu~tion shall be used, if WASHINGTON NUCLEAR - UNIT 2 3/4 7-13
Page 3 of 7 INSERT A If du< ing the functional
- testing, additional testing is required due to failure of snubbers, the unacceptable snubbers may be categorized into test failure mode group(s).
A test failure mode group shall include all unacceptable snubbers that have a given failure mode and all other snubbers subject to the same failure mode.
Once a test failure mode group has been established, it can be separated for continued testing apart from the general population of snubbers.
However, all the unacceptable snubbers in this failure mode group shall be.counted as one unacceptable snubber for additional testing in the general population.
Testing in the failure mode group shall be based on the number of unacceptable snubbers and shall continue until no more failures are found or all snubbers in the failure mode group have been tested.
Any additional unacceptable snubbers found in the test failure mode group shall be counted for continued testing only for that test failure mode group.
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Page 4 of 7 PLANT SYSTEMS SURVEILLANCE RE UIREMENTS Continued g.
evaluated in a manner (stroking,
- testing, replace-ment etc.) to ensure their operability.
This evaluation h.
Functional Test Failure Anal sis (Continued) applicable, in selecting snubbers to be tested in an effort to determine the OPERABILITY of other snubbers irrespective of type which may be subject to the same failure mode.
For the snubbers found inoperable, an engineering evaluation shall be performed on the components to which the inoperable snubbers are attached.
The purpose of this engineering evaluation shall be to determine if the components to which the inoperable snubbers are attached were adversely affected by the inoperability of the snubbers in order to ensure that the component remains capable of meeting the designed service.
If any snubber selected for functional testing either fails to lock up or fails to move, i.e., frozen-in-place, the cause will be evaluated and, if caused by manufacturer or design deficienc all snubbers of the same type subject to the same defect shall be~ne-of the requirements stated in Specification 4.7.4e.
for snubbers not meeting the functional test acceptance criteria.
Functional Testin of Re aired and Re laced Snubbers Snubbers which fail the visual inspection or the functional test acceptance criteria shall be repaired or replaced.
Replacement snubbers and snubbers which have repairs which might affect the functional test results shall be tested to meet the functional test criteria before installation in the unit.
Mechanical snubbers shall have met the acceptance criteria subsequent to their most recent
- service, and the freedom-of-motion test must have been performed within 12 months before being installed in the unit.
Snubber Service Life Pro ram pl I:
- r The service life of hydraulic and mechanical snubbers shall be moni-tored to ensure that the service life is not exceeded between sur-veillance inspections.
The maximum expected service life for various
- seals, springs, and other critical parts shall be determined and established based on engineering information and shall be extended or shortened based on monitored test results and failure history.
Critical parts shall be replaced so that the maximum service life will not be exceeded during a period when the snubber is required to be OPERABLE'he parts replacements shall be documented and the documentation shall be retained in accordance with Specification
- 6. 10. 2.
WASHINGTON NUCLEAR " UNIT 2 3/4 7-14 or unexpected:
transient events
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page 5 of 7 10 NTINVE ESTING gQ G
ACCEPT 0
'10 20 30 40 50 60 70 80 90 '00 N
FIGURE 4. 7-1 SAMPLE PLAN 2)
FOR SNUBBER FUNCTIONAL TEST WASHINGTON NUCLEAR - UNIT 2 3/4 7-15
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Page 6 of 7 PLANT SYSTEMS BASES 3/4.7.4 SNUBBERS (Continued)
To provide assurance of snubber functional reliability, one of ee
+~4'unctional testing methods are used with the stated acceptance criteria:
1.
Functionally test 10K of a type of snubber with an additional~<7o tested for each functional testing failure, or 2.
Functionally test a sample size and determine sample acceptance or continue testing*+egeeM+a using Figure 4.7-1<.g
- Iftesting continues to betwen 100 - 200 snubbers and still the accept region has not been reached, then the actual per-cent of population quality (C/N) should be used to indicate the probability of extended or 100 per cent testing.
A population quality of greater than or equal to 5 percent failed snubbers will probably result in extended testing.
WASHINGTON NUCLEAR " UNIT 2 B 3/4 7-2a Amendment No. 40
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ONTROLLED COF y Page 7 of 7 PLANT SYSTEMS BASES SNUBBERS (Continued) 3.
Franc ally test resentative le size and de ine tenible acceptanc r rejection ing the state ation.
r Figure 4.7-1 was developed using "Wald's Sequential Probability Ratio Plan" as described in "guality 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 com-pletion 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 associated installation and maintenance records (newly installed snubbers, seal
- replaced, spring replaced, in high radiation area, in high temperature area, etc.).
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 operating conditions.
These records will provide statis-tical bases for future consideration of snubber service life.
3/4. 7. 5 SEALED SOURCE CONTAMINATION The li&itations on removable contamination for sources requiring leak
- testing, including alpha emitters, is based on 10 CFR 70.39(c) limits for plutonium.
This limitation will ensure that leakage from byproduct,
- source, and special nuclear material sources will not exceed allowable intake values.
Sealed sources are classified into three groups according to their use,.with surveillance requirements commensurate with the probability of damage to a source in that group.
Those sources which are frequently handled are required to be tested more often than those which are not.
Sealed sources which are continuously enclosed within a shielded mechanism, i.e.,
sealed sources within radiation monitoring devices, are considered to be stored and need not be tested, unless they are removed from the shielded me'chanism.
3/4 7.6 FIRE SUPPRESSION SYSTEMS The OPERABILITY of the fire suppression systems ensures that adequate fire suppression capability is available to confine and extinguish fires occurring in any portion of the facility where safety-related equipment is located.
The fire suppression system consist'f the water system, spray and/or sprinkler systems, CO> systems, Halon systems, and fire hose stations.
The collective capability of the fire suppression systems is adequate to minimize potential damage to safety"related equipment and is a major element in the facility fire protection program.
WASHINGTON NUCLEAR - UNIT 2 8 3/4 7-3
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