ML20098D279
| ML20098D279 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/08/1992 |
| From: | Marsh L Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20098D283 | List: |
| References | |
| GL-90-09, GL-90-9, NUDOCS 9205280174 | |
| Download: ML20098D279 (20) | |
Text
,
-l, >R RIOg<>,
4' "
s UNITED STATES n
3
,i NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555
\\*****/
NORTHERN STATES POWER COMPANY DOCKET NO. 50-282
'RAIRIE ISLAfJD NQCLEAR GENERATING PLANT. UNIT NO. 1 AMENDMENT TO FACILITY OPERATlN3 LICENSE Amendment No. 98 License No. DPR-42 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Northern States Power Company (the licensee) dated January 10, 1992, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; L.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license ammdment, and paragraph 2.C.(2) of Facility Operating License No. DPR-42 is ;iereby amended to read as follows:
{
l l-h P
l
2 Technical Soecifications The Technical Specifications contained in Appendix A, as revised through Amendment No.98, are hereby incorporated in the license The licensee shall operate the facility in accordance with_the Technical Specifications.
3.
This license amendment is effective 30 days after its date of issuance l
FOR THE NUCLEAR REGULATORY COMMISSION
,h L. B. Marsh, Dire lor c
Project Directorate III-I Division of Reactor Projects III/IV/V.
Office of Nuclear Reactor Regulatton
Attachment:
Ch..iges to the Technical
-it
..t, Specifications ey Date of Issuance: May 8, 1992 in
'n's 1
h
,G
,6
4 ATTACHMENT TO LICENSE AMENDMENT NO. 98 FACILITY OPERATING LICENSE NO DPR-42 DOCKET N0. 50-282 Revise Appendix A Technical Specifications by removing the pages identified-below and inserting the attached pages. The revised pages are identified by amendment number and contain marginal lines indicating the area of change REMOVE INSERT TS - xii TS - xii TS - 4.13-1 TS - 4.13-1 TS - 4.13-2 TS - 4.13-2 TS - 4.13-3 TS - 4.13-3 Table TS 4.13-1 Page I of 2 Table Ts 4.13-1 Page 2 of-2 TS B 4.13-1 TS B 4.13-1 l-
TS xii TECHNICAL SPECIFICATIONS LIST OF TABLES TS TABLE TITLE 3.5-1 Engineered Safety Features Initiation Instrument Limiting Set Points 3.5-2 Instrument _ Operating Conditions for Reactor Trip 3.5-3 Instrument Operating Conditions for Emergency Cooling System 3.5 4 Instrument operating conditions for Isolation Functions 3.5 5 Instrument operating conditions for ventilation Systems 3.5 6 Instrument Operating Conditions for Auxiliary Electrical System 3.9-1 Radioactive Liquid Effluent Monitoring Instrumentation-3.9 2 Radioactive Caseous Effluent Monitoring instrumentation 3.14-1 Safety Related Fire Detection Instruments 3.15-1 Event Monitoring instrumentation Process & Containment 3.15-2 Event Monitoring instrumentation - Radiation 4,1 1 Minimum Frequencies for Checks, Calibrations and Test of Instrument Channels 4.1 2A Minimum Frequencies for Equipment Tests 4.1-2B Minimum Frequencies for Sampling Tests 4.2-1 Special Inservice Inspection Requirements 4.4-1 Unit 1 and Unit 2 Penetration Designation for Leakage Tests 4.10-1 Radiation Environmental-Monitoring Program (REMP)
Sample Collection and Analysis 4.10 2 RFMP - Maximum Values for the Lower Limits of Detection 4.10 3 RFMP - Reporting Levels for Radioactivity Conce?Jritions in Environmental Samples 4 12-1 Steam Generator Tube Inspection 4.13-1 Snubber Visual Inspection Interval 4.17-1 Radioactive Liquid Effluent Monitoring Instrumentation Surveillance Requitsments 4.17-2 Radioactive Caseous Effluent Monitoring instrumentation Surveillance Requirements 4.17 3 Radioactive Liquid Waste' Sampling and Analysis Program 4.17-4 Radioactive Caseous Waste Samplin5 and Analysis Program 5.5-1 Anticipated Annual Release of Radioactive Material in
' Liquid Effluents From Prairie Island Nuclear Generating Plant (Per Unit) 5.5-2 Anticipated Annual Release of Radioactive Nuclides in Caseous Effluent From Prairie Island Nuclear Generating Plant (Per Unit) 6.1-1 Minimum Shift Crew Composition Prairie ' Island Unit 1 - Amendment No. 9J, 98 Prairi-a Island Unit 2 - Amendment No. EA, 91
TS.4.13-1
~
A.13 SNUBBERS Arolicability Applies to periodic testing and surveillance requirements of safety related hydraulic snubbers.
Objective To verify the OPERABILITY of hydraulic snubbers.
Specifiesti2D The following surveillance requirements app 1v to all safety related snubbers.
These requirements augment the inspections required by Section XI of the ASME Code.
A.
As used in this specification, " type of snubber" shall mt J' 4. 'J ')
T of the same design and manufacturer, irrespective of cr'-e Y/,
Snubbers are categorized as "accessic.e" or "inar(r. 1: L>' b-
,(
o their accessibility for inspection during reactes c;- i>t,0*
E. of these categories (inaccessible and accessible) m r ',
Net ut-independently according to the schedule determines by i r.
IS.4.13 1.
The visual inspection interval for each type of snubber shall be determined based upon the criteria provided in Table TS.4.131.
B.
Visual inspections shall verify that (1) the snubber has no visible indications of damage or impaired OPERABILITY, (2) attachments to the foundation or supporting structure are functional, and (3) fasteners for the attachment of the snubber to the component and to the snubber anchora6e are functional.
Snubbers which appear inoperable as a result of visual inspections shall be classified as unacceptable and may be reclessified acceptable for the purpose of establishing the next visual inspection interval, provided that:
- a. The cause of the rejection is clearly established and remedied for that particular snubber end for other snubbers irrespective of type that may be generically susceptible; and
- b. The affected snubber is functionally tested in the as-found condition and determined OPERABLE per Specification 4.13.D.
All hydraulic snubbers found connected to an inoperable common hydraulic fluid reservoir shall be counted as unacceptable for determining the next incpection interrcl. A review and evaluation shall be performed and docum:rted to justify continued operation with an unacceptable snubber.
If continueo operation cannot be justified, the snubber shall be declared inoperable and the applicable action statement requirements sh.11 be met.
Prairie Island Unit 1 - Amendment No J/, 5p, 73, 98 Prairie Island Unit 2 - Amendment No. 8, ff, EE, 91
TS.4.13 2 C.
Except as specified below, functional testing of snubbers shall be conducted at least once per 18 months.
Ten percent of the total of each type snubber shall be functionally tested either in place or in a bench test.
For each snubber that does not meet the functional Oest acceptance criteria in Specification 4.13.D below, an addisional ten percent of that type of snubber shall be functionally tested until no more failures are found or all snubbers of that type have been tested.
The representative sample selected for functional testing shall include the various configurations, operating environments, and the range of size and capacity of the snubbers Twenty five percent of the sample shall include snubbers from the following three categories.
- a. The first snubber away from a reactor vessel nozzle
- b. Snubbers within five feet of heavy equipment (valve, pump.
turbine, motor, etc.)
- c. Snubbers within ten feet of the discharge of a safety / relief valve Snubbers identified as "High Radiation Area" or " Difficult to Remove" are exempt from functional testing provided a justifiable basis for exemption is presented for Commission review; snubber life testing is performed to qualify snubber operability for all design conditions; or snubbers of the same type, configuration, and similar service have been tested for a ten year period and no failures have occurred.
In such exempt cases, a qualitative test report shall be on file to substitute for the required functional testing.
In addition to the regular sample and specified re-su.pling, soubbers which failed the previous functional test shall be retested during the next test period.
If a spare snubber has been installed in place of a failed snutber, then both the failed snubber, if it is repaired and installed in another position, and the spare snubber shall be retested.
If any snubber selected for functional testing either fails to lockup er fails to move (i.e., frozen in place) the cause shall be evaluated and all snubbers subject to the same defect shall be functionally tested., This testing is in addition to the regular sample and specified re samples.
D.
Hydraulic snubber functional tests shall verify that;
- a. Activation (restraining action) is achieved within the specified range of velocity or acceleration in both tension and compression.
i l
(
- b. Snubber bleed, or release rate, where required, is within l
the specified range in compression or tension.
For snubbers I
specifically required to not displace under continuous load, the ability of the snubber to withstand load withor* displace-ment shall be verified.
l Prairie Island Unit 1 - Amendment No. 79, 50, 73, 98 Prairie Island Unit 2 - Amendment No. 8, //, EE, 91 l
l
.=%
TS.4.13-3 E.
An engineering evaluation shall be performed for all components supported by inoperable snubbers.
The purpose of this engineering
)
evaluation shall be to determine if the components were adversely J
affected by the inoperable snubber (s) to ensure that the components remain capable of meeting the designed service.
F.
The installation and maintenance records for each snubber shall be reviewed at least once every 18 nonths to verify that the indicated service life vill not be exceeded prior to the next scheduled snubber service life review.
If the indicated service life vill be exceeded, the snubber service life shall be reevaluated or the snubber shall be replaced or reconditioned to extend its service life beyond the date of the next scheduled service life review.
This re evaluation, replacement, or reconditioning shall be 4
indicated in the records.
b
=
Prairie Island Unit 1 - Amendment No. If, 50, 73, SJ, 98 Prairie Island Unit 2 - Amendment No. B, ff EE, Ef, 91
~ - -. -
lt,m % ^
^
e' 7,-
TABLE TS.4.13 1 Page 1 of 2 TABLE TS.4.13 1 SNUBBER VISUAL INSPECTION INTERV&L Number of Unaccentable Snubbers
. Population-Column A-Column B Column C or Category-
_ Extend Intervcl -
_ Repeat Interval Reduce Interval 1 Notes 1 mnd 21 (Notes 3 and 6)
(Notes 4 and 6)
(Notes 5 and 6) 1 0
0 1
80 0
0 2
100 0
1 4
150 0
3 8
200 2
5 13 4
300 5
12 25 4001 8
18 36 500 12 24 48 750 20 40 78
'1000 or greater 29 56 109,
1 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 accessibility during power operation, as accessible or inaccessible. These categories may be examined separately or jointly.- However, that decision must be made and documented before any inspection and that decision shall be used asLthe basis upon-which to determine the next inspection-interval for-that category.
Note 2:
Interpolation between population or. category sizes and the-_ number'of
-unacceptable snubbers is permissible. -Use next-lower _ integer for the value-of the limit for Columns A, B or C-if that integer includes a-fractional:value of unacceptable snubbers as determined by interpolation, s
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.
Note 4:
If the number of unacceptable snubbers is equal to r less than the number ir Column B but-greater than the number in Column A, the next-inspection interval shall be the same as the previous interval.
Prairie Island Unit 1 - Amendment No. 98 Prairie Island UnitJ2 -- Amendment No. 91
0 TABLE 75.4.13 1 Page 2 of 2 Note 5:
If the number of unacceptabic 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 nunber of unacceptable snubbers is less than the number in Column C but greater than the number in Column B, the next interval shall be reduced proportionally by interpolation, that is, the previous interval shall be reduced by a facto that is one third of the ratio of the difference between the number af unacceptable snubbers found during the. previous interval and the number in Co1 2n B to the difference in the numbera in Columns B and C.
Note 6: All inspection intervals up to and including 48 months may be adjusted a maximum of plus or minus 25%.
s Prairie Island Unit 1 - Amendment tio. 98 Prairie Island Unit 2 - Amencment tio. 91 I
_, _ -,, - - - - - - - - - - - ~ - - - - ~ ~ - - ' - - - "
B.4.13 1 4.13 Sb*UBBERS Bases The visual inspection frequency is based upon maintaining a constant level of snubber protection to systems. Therefore, the required inspection interval varies inversely with the observed snubber failures and is determined by the number of inoperable snubbers found during an inspection.
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, When the cause of the rejection of a snubber is clearly established and remedied for that snubber and for any other snubbers that may be gererically succe ptible, and verified by inservice functional testing, that snubber may be e~ampted from being counted as inoperable.
Genetically susceptible snubbers are those which are of a spec.ific make or model and have the same design features directly related to rejection of the snutber by visual inspection, or are similarly located or exposed to the same environmental conditions such as temperature, radiation, and vibration.
When a snubber is found inoperable, an engineering evaluation is performed, in addition to the determination of the snubber mode of failure, in order to determine if any safety-related component or system has been adversely affected by the inoperability of the snubber.
The engineering evaluation shall determine whether or not the snubber mode of failure has imparted a significant effect or degradation on the supported component or system.
To provide assurance of snubber functional reliability, a representative sample of 10% of the installed snubbers will be functionally tested at 18 month intervals. Observed failures of these sample snubbers shall require functional testing of additional units.
The service life of a snubber is evaluated via manufacturer input and information through consideration of the snubber service conditions and associated installation and maintenance records (newly installed snuober, seal replaced, spring replaced, in high radiation area, in high temperature area, etc...).
The requirement to nonitor 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 statistical bases for future consideration of snubber service life.
All safety related snubbers installed or planned for use at Prairie Island are hydraulic snubbers. No mechanical snubbers are used.
Prairie Island Unit 1 - Amendment No. 9J, 98 Prairie Island Unit 2 - Amendment fio. EA, 91 l
so nouq
+
'3,,(
' t UNITED STATES n
5 E
NUCLEAR REGULATORY COMMISSION
- k.
[3 l W A$mNoTON, D.C. 20r65 o,%,,8 NORTHERN STATES POWER COMPANY DOCKET NO. 50-306 PRAIRIE ISLAND NUCLEAR SENERATING PLANT. UNIT NO. 2 AMENDMENT TO FACillTY OPERATING LICENSE Amendment No. 91 License No. DPR-60 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Northern States Power Company (the licensee) dated January 10, 1992, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-60 is hereby amended to read as follows:
. Technical Snecifications The Technical Specifications contained in Appendix A, as revised through Amendment No.91, are hereby incorporated in the license.
The licensee shall operate the facility in accordance with the Technical Specifications.
3.
This license amendment is effective 30 days after its date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION L. B. Marsh, Director Project Directorate 111-1 Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: May 8, 1992
1.
ATTACHMENT TO LICENSE AMENDMENT NO. 91 FACILITY OPERATlhG LICENSE NO. j)PR-60 DOCKET NO. 50-306 Revise Appeadix A Technical Specifications by removing the pages identified below and inserting the attached pages. The revised pages are identified by amendment number and contain marginal lines indicating the area of change REMOVE INSERT TS - xii TS - xii TS - 4.13-1 TS - 4.13-1 TS - 4.13-2 TS - 4.13-2 TS - 4.13-3 TS - 4.13-3 Table TS 4.13-1 Page 1 of 2 Table Ts 4.13-1 Page 2 of 2 TS B 4.13-1 TS B 4.13-1 m
v b
u.
___-_______.___m____.___-____-____._._____________m_
__________.____-____...__-_______.-____-.m.
.i
.. ~. _.
TS xii TECHNICAL SPICIFICATIONS LIST OF TABLIE IlkLg Ts TAEtt 3.5-1 Engineered Safety Features Initiation Instrument Limiting Set Points 3.5 2 Instrument Operating Conditions for Reactor Trip 3.3 3 Instrument Operating conditions for Emergency Cooling system 3.5 4 Instrument Operating conditions for Isolation Functions 3.5 5 Instrument Operating Conditions for Ventilation Systems 3.5 6 Instrument Operating Conditions for Auxiliary Electrical System 3.9 1 Radioactive Liquid Effluent Monitoring Instrumentation 3.9 2 Radioactive Caseous Effluent Monitoring instrumootation 3.14 1 Safety Related Fire Detection Instruments
-3.15-1 Event Monitoring instrumentation - Process & Containment 3.15 2 Event Monitoring instrumentation - Radiation 4.1 1~
Minimum Frequencies for Checks. 'elibrations and Test of Instrument Channels 4.1 2A Minimum Frequencies for Equapeant Tests 4.1 2B
-Minimum Frequencies for Sampling Tests 4.2-1 Special Inservice Inspection Requirements 4.4 1 Unit 1 and Unit 2 Penetration Designation for Leakage Tests 4.10-1 Radiation Environmental Monitoring Program (REMP)
Sample Col?ection and Analysis 4.10-2 RFMP Maxir.a Values for the lower Limits of Detection 4.10 3-RFMP - Reporting Levels for Radioactivity concentrations in Environmental Samples
-4.12-1
-Steam Generator Tube Inspection 4.13 Snubber Visual Inspection Interval 4.17-1 Radioactive Liquid Effluent Monitoring Instrumentation Surveillance Requirements 4.17-2 Radioactive Caseous Effluent Monitoring instrumentation Surveillance Requirements 4.17-3 Radioactive Liquid Waste ' Sampling and Analysis-Program 4.17 4 Radioactive Caseous Waste Sampling and Analysis Program 5.5 1-Anticipated Annual Release cf Radioactive Material in Liquid Effluents From Prairie Island Nuclear Generating Plant (Per-Unit)'
5.5 2
-Anticipated Annual Release of Radioactive Nuclides in Caseous Effluent From Prairie Island Nuclear Generating Plant (Per Unit) 6.1 1 Minimum-Shift crew Composition Prairie ' Island Unit 1 - Amendment No. 91. 98 Prairie Island Unit 2 - Amendment No. Et, 91
TS.4.13 1 4.13 SNUBEERS Arolicabiliev Applies to perf % ic testing and surveillance requirements of safety related hydraulic snubbers.
Obiective To verify the OPERABILITY of hydraulic snubbers.
Seecification The following surveillance requirements apply to all safety related snubbers. These requirements augment the inspections recuired by Section XI of the ASME Code, i
A.
As used in this specification, " type of snubber" shall mean snubbers of the same design and manufacturer, irrespective of capacity.
Snubbers are categorized as " accessible" or
- inaccessible". based on their accessibility for inspection during reactor operation. Each ok these categories (inaccessible and accessible) may be inspected independently according to the schedule determined by Table TS.4.13 1.
The visus 1 inspection interval for each type of snubber shall be determined based upon the criteria provided in Table TS.4.131.
B.
Visual inspections shall verify that (1) the snubber has no visible indications of damage or impaired OPERABILITY, (2) attachments to the foundation or supporting structure are functional, and (3) fasteners for the attachment of the snubber to the component and to the snubber anchorage are functional. 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:
- a. 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; and
- b. The affected snubber is functionally tested in the as found condition and determined OPERABLE per Specification 4.13.D.
All hydraulic snubbers found connected to an inoperable common hydraulic fluid reservoir shall be counted as unacceptable for determining the next inspection interval. A review and evaluation shall be perforced and documented to justify continued operation with an unacceptable snubber.
If continued operation cannot be justified, the snubber shall be declared inoperable and the app'icable action statement requirements shall be met.
Prairie Island Unit 1 - Amendment No If, 59, 73, 98 l
Prairie Island Unit 2 - Amendment No. E, #f, EE, 91
_ _ _ _ _ _ ~ - _. _ _ _ _ _. _ _ _ _ _ _ _
l TS.4.13-2 C.
Except as specified below, functional testing of snubbers shall be conducted at least once per 18 months. Ten percent of the total of each type snubber shall be functionally tested either in place or in a bench test.
For each snubber that does not moet the functional test acceptance criteria in Specification 4.13.D belov, an additional ten percent of that type of snubber shall be functionally tested until no more failures are found or all snubbers of that type have been tested.
The representative sam. ale selected for functional testing shall include the various configurations, operating environmente, and the range of size and capacity of the snubbers.
Twenty five percent of the sample shall include snubbers from the following three categories,
- a. The first snubber away from a reactor vessel nozzle
- b. Snubbers within five feet of heavy equipment (valve, pump.
turbine, motor, etc.)
c, Snubbers within ten feet of the discharge of a safety / relief valve Snubbers identified as 'High Radiation Area" or " Difficult to Remove" are exempt from functional testing provided a justifiable basis for exemption is presented for Commission review; snubber life testing is performed to qualify snubber operability for all design conditions; or snubbers of the same type, configuration, and similar service have been tested for a ten year period and no failures have occurred.
In such exempt cases, a qualitative test report shall be on file to substitute for the required functional testing.
In addition to the regular sample and specified re sampling, snubbers which failed the previous functional test shell be retested during the next test period.
If a spare snubber has been installed in place of a failed snubber, then both the failed snubber, if it it repaired and installed in another position, and the spare snubber shall be retested.
If any snuhber selected for functional testing either fails to lockup :. fails to move (i.e., frozen in place) tha cause r, hall be evaluated and all snubbers subject to the same defect shall be functionally tested., This testing-is in addition to the regular sample and specified re samples.
D.
Hydraulic snubber-functional tests shall verify that;
- a. Activation (restraining action) is achieved within the specified range of velocity or acceleration in both tension and compression.
- b. Snubber bleed, or release rate, where required, is within the specified range in_ compression or tension.
For snubbers specifically required to not displace under continuous load, the ability of the snubber to withstand load without displace-cent shall be verified.
Prairie Island Unit 1 - Amendment No. JA, 50, 73, 98 Prairie Island Unit 2 - Amendment No. E, J A. ES, 31
\\
7S.4.13 3 E.
,Ji engineering evaluation shall be performed for all components supported by inoperable snubbers.
The purpose of this engineering evaluation shall be to determine if the components were adversely affected by the inoperable snubber (s) to ensure that the corponents rossin capable of meeting the designed service.
T.
The installation and maintenance rscords for each snubber shall be reviewed at least once every 18 months to verify that the indicated service life vill not be exceeded prior to the next scheduled snubber service life review.
If the indicated service life vill be exceeded, the snubber service life shall be reevaluated or the snubber shall be replaced or reconditioned to extend its service life beyond the data of the next scheduled service life review.
This re evoluation, repin:ement, or reconditioning shall be
@gj inuicated in the records.
's d
rairie Island Unit 1 - Amendment No. 25 Ep. 7), 92, 98 a
i rairie Island Unit 2 - Amendment No. E. AA, (f EA, 91 I
.I
.s.n % =
. s TAB 12 TS.4.13+1
)
Page 1 of 2 TABLE 75.4.13 1
$WBBER VISUAL INSPECTION INTERVAL Number of Unaccentable Snubbers Population Column d Column B Column C or Category Extend Interval Repe a Interval Reduce Interval IFores i uL21 INotes ? and 6)
(Notes 4 and 6)
Dip 1r * $ and 61 1
0 0
1 80 0
0 2
100 0
1 4
150 0
3 8
200 2
5 13 300 5
12 25 l
400 8
18 36 500 12 24 48 750 20 40 78 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 accessibility during power operation, as accessible or inaccessible.
These categories may be exanined separately or jointly. However, that decision must be made and documented before any inspection and that decision shall be uced as the basis upon which to detennine the next inspection interval for that category.
Note 2:
Interpolation between population or category sizes and the number of unacceptable snubbers is permissible. Use next lower integer for the value of the limit for Columns A, B or C if that integer includes a fractional value of unacceptable snubbers as determined by interpolation.
l Note 3:
If the number of unacceptable snubbers is equal te or less than the number in Column A, the next inspection interval may be twice the previous interval but not greater than 48 nonths.
Note 4:
If the number of unacceptable snubbers is equal to or less than the number in Column B but greater ti.an the number in Column A, the next inspection interval shall be the same as the previous interval.
!Tairie Island Unit 1 - Amendment No. 98 Prairie Island Unit 2 - Amendment No. 91
TA.RE TS.4.13 1 Page 2 of 2 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 tvo thirds of the previous interval. However, if the number of unacceptable snubbers is less than the number in Column C but greater than the number in Column B, the next interval shall be reduced proportionally 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 & to the difference in the numbers in Columns B and C.
Note 6: All inspection !ntervals up to and including 48 nonths may be adjusted a waximum of plus or ninus 254.
Prairie Island Unit 1 - Amendment No. 98 Prairie Island Unit 2 - Amendment No. 91
k B.4.13 1 4.13 shTFFEgg 21Lt1 The visual inspection frequency is based upon maintaining a constant level of snubber protection to systems. Therefore, the required inspection interval varies inversely with the cbserved snubber failures and is determined by the number of inoperable snubbers found during an inspection.
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 256) may not be used to lengthen the required inspection interval. Any inspection whose results require a shorter inspection interval vill override the previous schedule.
When the cause of the rejection of a snubber is clearly established and recedied for that enubber and for any other snubbers that may be generically susceptible, and verified by inservice functional testing 3 that snubber may be exempted from being counted as inoperable.
Generically susceptible snubbers are those which are of a specific nake or nodel and have the same design features directly related to rejection ot' the snutber by visuel inspection, or are similarly located or exposed to the same environmental conditions such as temperature, radiation, and vibration.
When a snubber is found inoperable, an engineering evaluation is perforced, in addition to the determination of the snubber mode of failure, in order to determine if any safety.related component or system has been adversely affected by the inoperability of the snubber. The engineering evaluation shall determine whether or not the snubber mode of failure has imparted a significant effect or degradation on the supported comp onent or system.
To provide assurance of snubber functional reliability, a representative sanple if 10% o; the installed snubbers vill be functionally tested at 18 nonth it,tervals.
Observed failures of these sample snubbers shall require functional testing of additional units.
The service life of a snubber is evaluated via manufacturer input and information through consideration of the snubber service condition: and
.ated installation aad nalntenance records (newly installed anubber, ass' replaced, spring replaced, in high radiation area, in high se' teaterature area, etc...).
The requirement to monitor the snubber service life is included te ensure that the snubbers periodically undergo a perfornance evaluation in view of their age and operating conditions.
These records vill provide statistical bases for future consideration of snubber service life.
All safety.releted snubbers installed or planned for use at Prairie Island are hydraulic snubbers. No nechanical snubbers are used.
Prairie Island Unit 1 - Amendment No pl. 98 Prairie Island Unit 2 - Amendment No. $$ 91 i
i
~~__ -_ -_ -_
___m