ML20198H544
| ML20198H544 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/11/1995 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20198H541 | List: |
| References | |
| GL-90-09, GL-90-9, NUDOCS 9801130334 | |
| Download: ML20198H544 (6) | |
Text
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Serial Number 97-005 l
j Attachment #3 DukeIbwer Company McCauw Nuclear Generaten Department T.CMuaw I!!00liaren fenyRoad(MC0lVP)
Vice thsident NuntenmIte,1X280784985 (MA!54530 (MMn;4M9f'at g
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February 23, 1995 Document Control Desk o
U.S. Nuclear Regulatory Commission Washington, D.C'.
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McGuire Nuclear Station Docket Fos:
50-369 and 370 Relief Request 94-012: Snubber Insgection Intervals for 4
Unit 2 Dent Sir Pursuant to 10 CFR 50.55a (g) (5) (iii),
I am subm3tting the ottached.-d ief request for NRC review and approval.
Per NRC Ceneric Letter 90-09 dated December 11, 1990 on
' Alternative Requirements for Snubber Visual Inspection Corrective Actiona's
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Intervals and
...the staff has developed an altarnate schedule for visual inspections that maintains the same confidence level as the existing schedule and generally will allow the licensee to perform visual inspections and corrective actions during plant outages.
Because this line ' item TS improvement will reduce future occupational radiation exposure and is highly
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cost effective, the ternato inspection schedule is consistent with the Lotu.aission's policy s tateraent on TS improvements.
The attached relief request seeks relief from impractical snubber inspection frequencies and will invoke the snubber testing frequency as reflected in the current '4cGuire Nuclear Station
'Te:::hnical Specifications 3.7.8, Table 4 'l-1 which are the same as those. reflected in the referenced GL 90-09.
Should there be any questions regarding this matter, please contact James E. Snyder at (704) 875-4447.
Very truly yours, MA/
. C; McMe.in
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U.S.=-Nuclear Regulatory Commission February-13,-'1995 Page 2/3 xc: :Mr.
S. D. Ebneter~
Administrator,-Region II-U.S. Nuclear Regulatory Commission 101_Marietta:St., NW, Suite 2900
' Atlanta,1Ga.
30323
'Mr. Victor-Nerses "i**
U.S. Nuclear Regulatory Commission Office of Nuc? ear Reactor Regulation Mail-Stop idH25 Washington, D.C.. 20555 Mr. Robert E. Martin U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washi'ngton,.D.C. 20555 m
'Mr. George F. Maxwell NRC Resident Inspector ~
McGuire Nuclear Station Dayne Brown, Chief Division of Radiation Protection P.-O. Box 27687 Raleigh, N. C.
27611-7687
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Jesse 1 O.JBhrbour!
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Jerry Goodman.
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. G.-A;..Copp.
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- Z.1L.. Taylor.
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- E. 4-Burchfield
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DUKE POWER COMPANY MCGUIRE NUCLEAR STATION Request for Relief From ASME Code Section XI Requirements I.
Component for Which Relief is Requested A. Name and Identification Number All Unit 2 safety-related snubbers.
B. Function 4
f Snubbers are designed to prevent pipe motion under d mamic loads.
3 C. ASME Section XI Code Class Provides support for Class 1,2,3 systems.
D._ Valve Category Not applicable.
II.
ASME Code Section Requirement that has been determined to be impractical.
ASME Boiler and Pressure Vessel Code Section XI, article IWF-5000.
III.
Basis for Requesting Relief The 1989 ASME Boiler and Pressure Vessel Code Section XI, Article IWF-5300 (a) states: ' Inservice examinations shall be performed in accordance with the first Addenda to ASME/ ANSI OM-1987, Part 4 (publi.,hed 1988), using the VT-3 visual examination method described in IWA-2213." Paragraph 2.3.2.2 of the first Addenda to ASME/ ANSI OM-1987, Part 4 states that exaninations shall be conducted at 18 month intervals +25%.
If unacceptable snubbers are revealed, the interval for subsequent inspections shall be reduced in accordance with the following table:
Number of Unacceptable Months to Subsequent Snubbers Examination 0
18 1
12 2
6 3,4 4
5,7 2
>8 1
McGuire' Unit 2 Technical Specifications 3/4.7.8, SNUBBERS has a surveillance frequency not to exceed 48 months which is altered based on the number of unacceptable snubbers found during the previous inspection in proportion to the sizes of the various snubber populations or categories.
See tne attached copy of the subject TS Table 4.7-2, SNUBBER VISUAL INSPECTION INTERVAL.
The examination interval requirements in the McGuire Unit 2 TS Table 4.7-2 are based on NRC Generic Letter 90-09, ' Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions.'
Prior to the incorporation of GL 90-09 into the TS, the examination inspection interval ~in the TS was idencical to that in the first Addenda to ASME/ ANSI OM-1987, Part 4.
NRC GL 90-09 acknowledged that licencees having a large number of snubbers find that the 18 month visual inspection schedule in the first addenda to ASME/ ANSI 0d-1987, part 4 is excessively restrictive and that some licensees have spent a significant amounc. of resources and have subjected plant personnel to unnecessary radiological expcsure to comply with the visual examination requirements without increasing the confidence level in snubber operability.
McGuire Unit 2 has 335 snubbers subject to the inservice inspection per IWA-5000. McGuire Unit 2 is currently on a fuel cycle length of approximately 18 months.
In order to comply with the current ASME requirements of IWF-5000, Duke Power would be required to perform VT-3, visual examinations on all 353 snubbers within the inservice inspection program at every refueling outage.
This examination frequency is twice that presently required by the approved TS 3/4.7.8 and significantly greater than that required under Sectica XI codes through the 1986 edition.
As indicated in NRC GL 90-09, this increased inspection per ASME requirements does not increase the confidence level in snubber operability above that obtained by the requirements of NRC GL 90-09.
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- IV.. Alternate Testing
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As:an alternative to the requirements o'f ASME Section XI, IWF-
- 5000,-J. paragraph
- IWA-5053 :(e)-which invokes the inspection
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frequency.in-paragraph 2.3.2.2 of the first-Addenda'to ASME/ ANSI'
- OH-1987,--Part 4~(published-in 1988),-VT-3,_; visual inspection.of snubbersLwithin the Section XI inservice inspection boundaries shall be examined on a-schedule as provided by McGuire~ Nuclear Station TS 3/4.7.8,' Table 4.7-2.
For the. purposes of determining I
inspection' frequency, the-snubbers within the inservice tboundaries shall be considered part of the total population of snubbers inspected under'TS 3/4.7.8.
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PLANT SYSTEMS 3/4.7.8 SNUBBERS LIMITING CONDITION FOR OPERATION I
3.7.8 All snubbers shall be OPED.ABLE.
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 S 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 inoparable and follow the appropriata ACTION statement for that system.
SURVEllLANCE REQUIREMENTS 4.7.0 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 As used in this specification, type of snubber shall mean snubters of the sake design and manufacturer, irrespective of capacity.
b.
Visual Inspections Snubbers arc categorized as inaccessible or accessible during reactor operation and may be treated independently.
Each of these categories inaccessible and accessible) ma be inspected independently accord-ng to the schedule detert:ined b Table 4.7-2.
The visual insoection 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) l Amendment No.108 (Unit 2).
Table 4.7-2 (continued)
SNUBBER VISUAL INSPECTION INTERVAL
.,o-Notn 4:
If the number nf unacceptable snubbers is equal to or less than the Column 8 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 pr2Vious inte. val. However, if the number.of.uoaccep-e 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 i reduced by a factor that is one third of tne ratio of the difference between the number of unacceptable snubbers found during the previous interval and the_nymber in Column B to the difference in the. numbers in Coltmns Yaiid C.
Note 6:
The provisions of Specificadan 4.0.2 are applicable for al1 inspection intervals up to and including 48 months.
t McGUIRE - UNITS 1 and 2 3/4 7-18b xmendment No.126 Unit 1 Amendment No.108 Unit 2
SURVEILLANCE REQUIREMENTS (Continued) c.
-Refueling Outage Inspections At each refueling, the systems which have the potential' for a severe oynamic event, specifically, the main steam system (upstraam 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 pum) turbine, and the letdown and charging portion of the CVCS system s1all be insp~ected to determine if
..s there has been a severe dynamic event.
In case of a sev eventi mechanical snubbers in that system which experib,eres baamic ced the event shall be ins >ected during the refueling outage to assure that the mechanical snu>bers have freedom of movement and are not-frozen up.
The inspection shall consist of verifying freedom of motion usin (1) manually induced snubber movement;
-(2) g= one of the following:
evaluation of in place snubber piston setting; (3) stroking the mechanical cnubber through its full range of travel.
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 t-independendent of the requirements of this specification.
d.
Visual Inspection Acceptance Criteria Visual inspections shall verify:
(1) that there are no visible indications of damage 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; a-McGUIRE - UNITSil and 2 3/4 7-19 Amendment No.126 Unit 1)
- Amendment No.108((Unit 2)
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l PLANT SYSTEMS SURVEILLANCE REQUIREMENTC (Continued) h e.
Functional Tests (Continued) 3)
An initial representative sample of fifty-five (55) snubbers shall be functionally tested. For each snubber which does not treet the functional test acceptance criteria, another sample of at least one-half the.stre 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 c(
snubbers found which do not meet the functional test ace 2ptance criteria.
This can be plotted using an " Accept" Ifne' Nhich follows j
the equation N = 55(1 + C/2).
Each snubber should be plotted is soon as it is tested.
If the potat plotted falls on or below the " Accept" line, testing may *.3 discontinued.
If the point i
plotted falls above the " Accept" line, testing must continue unless all snubbers ha o been tested.
The representative samples for the functional test sample plans shall be randomly selected from the snubbers required by Specift-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 t.est shall be retestad at the time of ther 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 cetermine if additional samples should be limited to the type of snubber which has failed the functional testing.
f.
Functional Test Acceptance Criteria The snubber functional test shall verify that:
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 takas place in both directionr avel; 2)
Snubber bleed, or release rate where required, is present in both tension anc' compression, within the specified range; 3)
Where required, the force requi ed to initiate or maintain motion of the snubber it within the specified range in both direction of travel; and 4)
For snubbers specifically required not to displace under continuous load, the ability of the snubber to withstand load without disolacement.
Testing methods may be used to measure parameters indirectly or parameters other than those specified if those results can be co.related to the specified parameters through established methods.
McGUIRE - UNITS 1 and 2 3/4 7-21 Amendment No. 96 (Unit 1)
Amendment No. 91 (Unit 2)
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