ML20080H595
| ML20080H595 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire  |
| Issue date: | 02/13/1995 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20080H586 | List: |
| References | |
| GL-90-09, GL-90-9, NUDOCS 9502220393 | |
| Download: ML20080H595 (7) | |
Text
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PLANT SYSTEMS ,
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3/4'.7.8 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.8 All snubbers shall be OPERABLE. The only snubbers excluded from the requirements are those installed on non-safety-related systems and then only !
if the failure or the failure of the system on which they are installed would ;
not have an adverse effect on any safety-related system.
APPLICABILITY: MODES 1, 2, 3, and 4. MODES 5 and 6 for snubbers located on systems required OPERABLE in those MODES.
ACTION:
With one or more snubbers inoperable, 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 4.7.8g. on the attached component or declare the attached ,
system inoperable and follow the appropriate ACTION statement for that system. -
SURVEILLANCE REQUIREMENTS 4.7.8 Each snubber shall be demonstrated OPERABLE by performance of the >
following augmented inservice inspection program and the requirements of Specification 4.0.5. ,
- a. Inspection Types
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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 reactor operation and may be treated independently. Each of these categories (inaccessibleandaccessible)maybeinspectedindependentlyaccord-ing to the schedule determined by Tat'1re 4.7-2. The visual inspection interval for each category of snubber shall be determined based upon the criteria provided in Table 4.7-2 and the first inspection inter-val determined using this criteria shall be based upon the previous inspection interval as established by the requirements in effect before Amendment Nos.126 and 108.
McGUIRE - UNITS 1 and 2 3/4 7-18 Amendment No.126 (Unit 1) 9502220393 950213 Amendment No.108 (Unit 2)
1 l}l Table 4.7-2 .
j SNUBBER VISUAL INSPECTION INTERVAL \
i NUMBER OF UNACCEPTABLE SNUBBERS l Population Column A Column B Column C 4 or Category Extended Interval Repeat Interval Reduce Interval t (Notes 1 and 2) (Notes 3 and 6) (Notes 4 and 6) (Notes 5 and 6) +
0 1 i 1 0 ,
0 2 80 0 l 0 1 4 100 t
150 0 3 8 200 2 5 13 300 5 12 25 8 18 36 l 400 12 24 48 500
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20 40 78 1 750 1000 or greater 29 56 109 Note 1: The next visual inspection interval for a snubber population or category size shall be determined based upon the previous inspection interval and the number of unacceptable snubbers found during that interval. Snubbers may be categorized, based upon their accessi- ;
bility during power operation, as accessible or inaccessible. The l categories may be examined separately or jointly. However, the !
j licensee must make and document that decision before any inspection ,
and shall use that decision as the basis upon which to determine the t :
next inspection interval for that category. ; l I
Note 2: Interpolation between population or category size and the number of i unacceptable snubbers is permissible. Use next lower integer for ,
the value of the limit for Columns A, B, or C if that integer I includes a fractional value of unacceptable snubbers as described by interpolation.
Note 3: If the number of unacceptable snubbers is equal to or less than the number in Column A, the next inspection interval may be twice the previous interval but not greater than 48 months.
McGUIRE - UNITS 1 and 2 3/4 7-18a Amendment No.126 (Unit 1)
Amendment No.108 (Unit 2)
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f Table 4.7-2 (continued)
SNUBBER VISUAL INSPECTION INTERVAL Note 4: If the number of unacceptable snubbers is equal to or less than the Column B but greater than the number in Column A, the next inspection shall be the same as the previous interval.
Note 5: If the number of unacceptable snubbers is equal to or greater than the number in Column C, the next inspection interval shall be two-thirds of the previous interval. However, if the number of unaccep-table snubbers is less than the number in Column C but greater than the number in Column B, the next interval shall be reduced propor-tionally by interpolation, that is, the previous interval shall be reduced by a factor that is one third of the ratio of the difference between the number of unacceptable snubbers found during the previous interval and the number in Column B to the difference in the numbers
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in Columns B and C.
Note 6: The provisions of Specification 4.0.2 are applicable for all inspection intervals up to and including 48 months.
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i McGUIRE - UNITS 1 and 2 3/4 7-18b Amendment No.126 Unit 1 Amendment No.108 Unit 2
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[' SbRVEILLANCEREQUIREMENTS(Continued)
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- c. Refueling Outage Inspections ,
At each refueling, the systems which have the potential for a severe dynamic event, specifically, the main steam system (upstream of the main steam isolation valves) the main steam safety and power-operated relief valves and piping, auxiliary feedwater system, main steam supply to the auxiliary feedwater pump turbine, and the letdown and
- charging portion of the CVCS system shall be inspected to determine if there has been a severe dynamic event. In case of a severe dynamic event, mechanical snubbers in that system which experienced the event shall be inspected during the refueling outage to assure ttat !
the mechanical snubbers have freedom of movement and are not frozan up. The inspection shall consist of verifying freedom of motion
- using one of the following: (1) manually induced snubber movement; (2) evaluation of in place snubber piston setting; (3) stroking the ,
mechanical snubber through its full range of trave'l. If one or more mechanical snubbers are found to be frozen up during this inspection, those snubbers shall be replaced or repaired before returning to power. The requirements of Specification 4.7.8b. are independendent of the requirements of this specification.
- d. Visual Inspection Acceptance Criteria -
Visual inspeci; ions shall verify: (1) that there are no visible indications of dam ge or impaired OPERABILITY, and (2) attachments
( to the foundation or supporting structure are secure. Snubbers which appear inoperable as a result of visual inspections "shall be classified as unacceptable and may be reclassified acceptable" for the purpose of establishing the next visual inspection interval, provided that: (1) the cause of the rejection is clearly established and remedied for that particular snubber and for other snubbers irrespective of type that may be generically susceptible; i
e McGUIRE - UNITS 1 and 2 3/4 7-19 Amendment No.126(Unit 1)
Amendment No.108(Unit 2)
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PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)
- d. Visual Inspection Acceptance Criteria (Continued) l and (2) the affected snubber is functionally tested in the as found condition and determined OPERABLE per Specification 4.7.8f. A hy-draulic snubber found with the fluid port uncovered and all hydraulic 1 snubbers found connected to an inoperable common reservoir shall be !
classified as unacceptable and may be reclassified acceptable by !
functionally testing each snubber starting with the piston in the i as-found setting, extending the piston rod in the tension-direction. , l
- e. Functional Tests During the first refueling shutdown and at least once per refuel'ing '
thereafter, a representative sample of snubbers shall be tested using one of the following sample plans. The large bore steam generator .
hydraulic snubbers shall be treated as a separate population for func-tional test purposes. A 10% random sample from previously untested i snubbers shall be tested at least once per refueling outage'until ,
the entire population has been tested. This testing cycle shall then :
begin anew. For each large bore steam generator hydraulic snubber i that does not meet the functional test acceptance criteria, at least 10% of the remaining population of untested snubbers for that testing i cycle shall be tested. The sample plan shall be selected prior to ,
the test period and cannot be changed during the test period. The .
NRC shall be notified of the sample plan selected prior to the test (t ,
period. .
- 1) At least 10% of the snubbers required by Specification 3.7.8 i shall be functionally tested either in place or in a bench test.
For each snubber that does not meet the functional test acceptance ;
criteria of Specification 4.7.8f., an additional 10% of the snubbers i shall be functionally tested until no more failures are found or until all snubbers have been functionally tested; or .
- 2) A representative sample of the snubbers required by Specifica- ,
tion 3.7.8 shall be functionally tested in accordance with l Figure 4.7-1. "C" is the total number of snubbers found not ;
meeting the acceptance requirements of Specification 4.7.8f !
(failures). The cumulative number of snubbers tested is denoted by "N." Test results shall be plotted sequentially in the order l of sample assignment (i.e., each snubber shall be plotted by !
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its order in the random sam)1e assignments, not by the order of testing). If at any time tie point plotted falls in the " Accept" l region, testing of snubbers may be terminated. When the point !
region additional snubbers plotted shall belies in theuntil tested " Continue Testing"in the point falls the ') Accept" region, or ;
all the snubbers required by Specification 3.7.8 have been 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, providing all snubbers tested with the failed equipment ;
during the day of equipment failure are retested; or j I
McGUIRE - UNITS 1 and 2 3/4 7-20 Amendment No.126(Unit 1) l Amendment No.108(Unit 2) l e
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n PLANT SYSTEMS
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- SURVEILLANCE REQUIREMENTS (Continued)
- e. Functional Tests (Continued) ..
- 3) An initial representative sample of fifty-five (55) snubbers shall be functionally tested. For each snubber which does not meet the functional test acceptance criteria, another sample of at least one-half the. size of the initial sample shall be tested until the total numbe'r tested is equal to the initial sample size multiplied by the factor, 1 + C/2, where "C" is the number of snubbers found which do not meet the functional test acceptance criteria. This can be plotted using an " Accept" line which follows j the equation N = 55(1 + C/2). Each snubber should be plotted as soon as it is tested. If the point plotted falls on or below the " Accept" line, testing may be discontinued. If the point plotted falls above the " Accept" line, testing must continue unless all snubbers have been tested.
The representative samples for the functional test sample plans shall be randomly selected from the snubbers required by Specifi-cation 3.7.8 and reviewed before beginning the testing. The review shall ensure as far as practical that they are representative of the various configurations, operating environments, range of sizes, and capacities. Snubbers placed in the same locations as snubbers which failed the previous functional test shall be ratested at the time of the next functional test but shall not be included in the sample plan. If during the functional testing, additional sampling is !
( required due to failure of only one type of snubber, the functional testing results shall be reviewed at that time to determine if ;
additional samples should be limited to the type of snubber which l has failed the functional testing. '
- f. Functional Test Acceptance Criteria The snubber functional test shall verify that: I
- 1) Activation (restraining action) is achieved within the specified range in both tension and compression, except that inertia dependent, acceleration limiting mechanical snubbers may be tested to verify only that activation takes place in both directions of travel;
- 2) Snubber bleed, or release rate where required, is present in both tension and compression, within the specified range; i
- 3) Where required, the force required to initiata or maintain motion of the snubber is within the speciffr,d range in both
- j direction of travel; and 5
- 4) For snubbers specifically required not to displace under continuous load, the ability of the snubber to withstand load without displa.coment.
Testing methods may be used to measure parameters indirectly or
- parameters other than those specified if those results can be
, correlated to the specified parameters through established methods.
McGUIRE - UNITS 1 and 2 3/4 7-21 Amendment No. 9n (Unit 1)
Amendment No. 31 (Unit 2)
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PLANT SYSTEMS .
SURVEILLANCE REQUIREMENTS (Continued)
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- g. Functional Test Failure Analysis
- 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 evaluation shall be used, if ~
applicable, in selecting snubbers to be tested in an effort to determine the OPERABILITY of other snubbers irrespective of type I 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 activate or fails to move, i.e., frozen-in place, the cause will be evaluated and, if caused by manufacturer or design deficiency, all snubbers of the same type subject to the same defect shall be evaluated ;
in a manner to ensure their OPERABILITY. This testing requirement '
shall be independent of the requirements stated in Specification 4.7.8e.
for snubbers not meeting the functional test acceptance criteria.
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- h. Functional Testing of Repaired and Replaced Snubbers i
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 i functional test result 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 freedom-of-motion test must have been performed within 12 months before being installed in the unit.
i, Snubber Seal Replacement Program i The seal service life of hydraulic snubbers shall be monitored to ensure that the service life is not exceeded between surveillance inspections. The expected service life for thi various seals, seal materials, and applications shall be determined and established i based on engineering information and the seals shall be replaced so that the expected service life will not be exceeded during a period when the snubber is required to be OPERABLE. The seal replacements shall be documented and the documentation shall be retained in accordance with Specification 6.10.2. l l
l McGUIRE - UNITS 1 and 2 3/4 7-22 Amendment No. 86(Unit 1) l {
Amendment No. 67(Unit 2)