ML043570184

ASME Section XI Inservice Inspection Program Revision to Snubber Testing Alternatives

ML043570184
Person / Time
Site:	North Anna
Issue date:	12/21/2004
From:	Matthews W Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
04-689
Download: ML043570184 (22)

Text

VIRGINIA ELECTRIC AND POWER COMPANY

RICHMOND, VIRGINIA 23261 December 21, 2004 10 CFR 50.55.a United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Serial No.:

04-689 NL&OS/ETS: Rev. 0 Docket Nos.: 50-338 License Nos.: NPF-4 50-339 N PF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNITS 1 & 2 ASME SECTION XI INSERVICE INSPECTION PROGRAM REVISION TO SNUBBER TESTING ALTERNATIVES North Anna Units 1 and 2 are in the third ten-year inservice inspection interval with the intervals scheduled to be completed on April 30, 2009 and December 13, 201 0 for Unit 1 and 2, respectively. The North Anna Unit 1 code of reference is the 1989 Edition of ASME Section XI. The North Anna Unit 2 code of reference is the 1995 Edition through the 1996 Addenda of ASME Section XI.

Currently North Anna tests snubbers in accordance with approved alternatives CS-3 for Unit 1 and CS-1 for Unit 2. The historical performance of snubbers at North Anna has not exceeded one snubber surveillance failure per inspection cycle since 1992.

In order to account for this historical performance, Dominion requests approval, pursuant to 10 CFR 50.55a (a) (3)

(i), of the proposed revision to CS-3 and CS-1 to permit use of a C value of C=l in lieu of C=2 in the snubber sampling formula of the Technical Requirements Manual (TRM).

The C value establishes, when exceeded, snubber functional test expansion requirements, as well as the initial sample size. Dominion considers that the proposed change will continue to provide an acceptable level of quality and safety consistent with the existing approved alternatives.

Alternatives CS-3 for North Anna Unit 1 and CS-1 for North Anna Unit 2 were approved by the NRC Staff in letters dated September 7, 2001 and May 9, 2002.

These alternatives addressed the use of Technical Specifications requirements with regard to examination and functional testing of snubbers in lieu of the ASME Section XI Code requirements. In a subsequent letter to the NRC dated June 13, 2002, Dominion notified the NRC that the testing requirements for snubbers had been relocated from the North Anna Units 1 and 2 Technical Specifications to the North Anna TRM as part of the Improved Technical Specification implementation and that no change to these requirements had been made.

The preservice inspection requirements for snubbers are contained in a separate alternative (CS-1) for Unit 1 and are included in CS-1 for Unit 2. Therefore, technical differences exist between the proposed alternatives. Another difference in the proposed

alternatives is the ASME Code edition for the Units.

North Anna Unit 1 utilizes the 1989 Code and Unit 2 utilizes the 1995 Edition with addenda up to and including the 1996 Addenda.

Pursuant to 10 CFR 50.55a (a) (3) (i), revised Alternatives CS-3 for North Anna Unit 1 and CS-1 for North Anna Unit 2, incorporating a C value of one (1) in the snubber sampling formula, are attached for review and approval.

In addition, the current referenced TRM Section, which details the inspection requirements for snubbers, is attached to support the staffs review of the requested revision to the previously approved alternative.

If you have any questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.

Very truly yours, W. R. Matthews Senior Vice President - Nuclear Operations uw-Attach men ts Commitments made in this letter: None

U.S. Nuclear Regulatory Commission Region I1 Sam Nunn Federal Atlanta Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. M. T. Widmann NRC Senior Resident Inspector North Anna Power Station Mr. S. R. Monarque NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Mail Stop 8-Hl2 Rockville, MD 20852 Mr. J. E. Reasor, Jr. (w/out attachments)

Old Dominion Electric Cooperative lnnsbrook Corporate Center Suite 300 4201 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. M. Grace (w/out attachments)

Authorized Nuclear Inspector North Anna Power Station North Anna Power Station Unit 1 Relief Request CS-3 Revision 1 Virginia Electric and Power Company (Dominion)

North Anna Power Station Unit 1

RELIEF REQUEST CS-3 REV.l

1.

II.

111.

IDENTIFICATION OF COMPONENTS Class 1,2, and 3 Snubbers CODE REQUIREMENT The ASME Code,Section XI, 1989 Edition, paragraphs IWF-5200(b) and IWF-5300(b) require the use of the ASMWANSI OM-1987, Part 4 (published in 1988)

Code to perform the preservice and inservice tests of Class 1,2, and 3 snubbers.

BASIS FOR ALTERNATIVE Integration of Section XI and OM (or alternatively ISTD) Codes into an effective, I coherent testing program along with associated required changes to the Technical Requirements Manual (TRM) (the snubber requirements were formerly in Technical Specifications) would require a significant amount of administrative activity (e.g.,

administrative procedure changes, reconciliation of Code requirement differences, technical procedure changes, etc.).

I An alternative approach to establish these administrative requirements for functional testing would be to revise the TRM to reference the appropriate I paragraphs of the OM or ISTD document. However, many of the requirements being removed from the existing TRM would be very similar, if not identical to the I requirements being added.

Again, this results in a significant amount of administrative activity, without enhancement in quality and safety.

A third approach, which is proposed, provides a means to accomplish the examination and testing required by the Code and regulation with a minimum additional I burden.

The current testing and examination requirements of TRM Section 3.7.5 formed the basis of the North Anna Unit 1 inservice testing program for snubbers for the past ISI interval (Pd interval).

Revision 1 of this relief request permits a C value of one to be utilized in the sampling formula of the TRM. The change from C=2 to C=l is desirable to take advantage of the historically low number of snubber failures experienced at North Anna. There has not been more than one failure from the required surveillance test group during any inspection cycle since 1992. The C value establishes the initial sample size and when exceeded, the snubber functional test expansion requirements.

NAPS Unit 1

To demonstrate that reducing the allowable number of small bore snubber functional test failures from two to one would continue to provide an adequate degree of testing, a comparison of the current TRM formula to the ASME OMa (ISTD) formula [ASME OMa Code - 1995 w/l996 Addenda, Subsection ISTD, Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants] has been performed assuming similar failure rates.

The current formula used in TRM Section 3.7.5 to determine the initial number of small bore snubbers to be functionally test each cycle is as follows: At least once per 18 months during shutdown, a representative sample of small bore snubbers which follows the expression 35[1 + C/2] where C=2 is the allowable number of small bore snubbers not meeting the acceptance criteria selected by the operator, shall be functionally tested either in-place or in a bench test.

The ASME Code OMa uses two different formulas for establishing the number of snubbers to be initially functionally tested. The determination of which plan to use is determined by the number of snubbers installed in the station. North Anna 1 has less than 370 snubbers and therefore the 10% plan is the preferred plan and will be used for comparison to the TRM formula.

The equation used in the TRM to define expanded sample size is 35(1 + C/2)(2/(C + 1))2(A-C) where C is the allowable number of functional failures (currently equal to two)

A is the total number of functional test failures in the initial sample size.

This equation is used when A exceeds C. Three functional test failures are required before an expanded sampling happens with C=2. With C=l the number of functional test failures required before expanded sampling begins will change to two.

The TRM is based on guidance given in NUREG 0452, Standard Technical Specifications for Westinghouse Pressurized Water Reactors, Revision 3 issued Fall 1980. NUREG-0452, Section 4.7.9 states in part The value C will be arbitrarily chosen by the applicant and incorporated into the expressions for the representative sample and for the resample prior to the issuance of the Technical Specifications. The TRM establishes a C to account for a certain number of failures before the testing population has to be expanded. This builds a failure rate into the group to be tested each outage before scope expansion would be required. The Code does not concern itself with this built in failure rate.

It is only concerned with testing an adequate number of snubbers to satisfy safety requirements.

ASME OMa Code (subsection ISTD 7.9.2) states that the additional sample size shall be at least one-half the size of the original sample. So the total number of snubbers to be tested, including initial test group, is NAPS Unit 1

N 2 0.1 n + C(O.l n/2)

N is the total number of snubbers to be tested, n is total number of snubbers in defined test group plan, and C is the number of unacceptable snubbers found through functional testing.

where TRM formula ASME OMa Code (same values both units) values (proposed Unit 1 c = 1 value)

Functional c=2 test failures (current value)

A = 3 102 158 82 A = 2 70 106 66 A = l 70 53 49 Reviewing the ASME OMa formula it can be seen that the Code does not define a pre-set number of allowable failures as the TRM does. The Code only requires that a minimum number of snubbers be tested based on the population [the 0.1 n factor] and an additional number of snubbers be tested for scope expansion based on the number found inoperable by testing [the C(O.ln/2) factor].

Substituting the number of snubbers for Unit 1, this formula reduces to:

I I

I Unit 1 N 2 32.6 + 16.3C A = O The initial sizes and expanded sample sizes once the allowable number of functional test failures is exceeded is provided for comparison in the table below.

70 53 33 I

(Note: the value A or functional test failures as defined by the TRM would be equivalent to the value C in the ASME OMa Code formula.)

From the above table it can be seen that the TRM formula with C=2 (current value) or C=l (proposed value), will require testing of essentially the same or more snubbers than the ASME OMa Code.

The comparison in the table demonstrates that changing the value of C in the TRM formula will continue to provide an adequate degree of testing when compared to the ASME OMa Code.

Based on the above snubber testing/sample size comparison, Virginia Electric and Power Company (Dominion) believes that the proposed TRM Section 3.7.5 (C=l ) functional testing requirements will continue to provide an acceptable level of quality and safety for inservice testing of snubbers. Additionally, the continued implementation of a program based on the TRM requires minimal administrative program change or TRM changes.

NAPS Unit 1

However, to comply with the preservice testing requirements of the Code verbatim, additional testing activity is required beyond the above proposal for inservice snubber testing activities.

Therefore, Dominion proposes that the inclusion of the snubber testing requirements contained in ASME OMa Code paragraph ISTD 5, Preservice Operability Testing, into the current snubber surveillance program provides an alternative with an acceptable level of safety and quality for the preservice testing requirements. The inclusion of these requirements into the snubber surveillance program achieves the preservice inspection requirements of the Code with only small administrative impact. No other requirements of ISTD will be implemented as part of this alternative.

IV.

PROPOSED ALTERNATE REQUIREMENTS Dominion proposes as an alternative to the Code requirements stated in Section II of this request, a snubber testing program comprised of the following elements: I

1) the preservice testing requirements of ISTD (ASME OMa 1996, Section IST) paragraph ISTD 5, Preservice Operability Testing, and I

2) the continued implementation of the surveillance requirements of TRM Section 3.7.5, Snubbers, (C=l), and

3) no other requirements of IST Code will be implemented as part of this alternative for snubber testing.

Dominion submits that the proposed alternative snubber testing program will continue to provide an acceptable level of quality and safety without the burden of substantial administrative changes to comply with Code requirements that add little or no value to quality or safety. Therefore, having met the criteria of 10 CFR 50.55a(a)(3)(i), an authorization to implement the proposed alternative is requested for the remaining portion of the third inspection interval for North Anna Unit 1.

NAPS Unit 1 North Anna Power Station Unit 2 Relief Request CS-1 Revision 1 Virginia Electric and Power Company (Dominion)

North Anna Power Station Unit 2

RELIEF REQUEST CS-1 REV.l I.

IDENTIFICATION OF COMPONENTS Class 1,2, and 3 Dynamic Restraints (Snubbers)

II.

CODE REQUIREMENT The ASME B&PV Code,Section XI, 1995 Edition with addenda up to and including the 1996 Addenda, paragraphs IWF-5200 (a) and (b) and IWF-5300 (a) and (b) require the use of the ASMWANSI OM-1987, Part 4 (published in 1988)

Code to perform the preservice and inservice examinations and tests of Class 1, 2, and 3 snubbers.

111.

BASIS FOR ALTERNATIVE This action proposes, as an alternative to the requirements of ASMUANSI OM-1987, Part 4 (published in 1988), to use the existing North Anna Power Station, Unit 2, Technical Requirements Manual (TRM) Section 3.7.5, Snubbers, (the snubber requirements were formerly in Technical Specifications) and specific paragraphs from ASME OMa-1996, Section IST, Subsection ISTD, lnservice Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants.

Differences exist between the referenced Code requirements and North Anna TRM Section 3.7.5, Snubbers. ASMUANSI OM-1 987, Part 4 (published in 1988)

[Part 41 contains requirements, which were removed from the plants Technical Specifications as recommended by Generic Letter 90-09, Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions (GL 90-09). The generic letter was issued on December 11, 1990 to reduce the burden placed upon licensees by the excessively restrictive inspection schedule then contained in the Technical Specifications.Section XI continues to require the excessively restrictive inspection schedule for snubbers by its requirement to use Part 4 in the preservice and inservice examination and testing of snubbers.

A later revision of the Part 4 standard, ASME OMa-1996, Section IST, Subsection ISTD, lnservice Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants, (ISTD), changed the excessively restrictive requirements to essentially agree with the recommendations of GL 90-09. The rulemaking of September 22, 1999 recognized this fact and included in the rule a provision to allow the use of ISTD provided the licensee revises the applicable Technical Specifications (now the TRM).

I However, the simple inclusion of ISTD into the TRM does more than alter the I excessive examination requirements of Part 4.

ISTD is written as a self-contained surveillance program for determining the continuing acceptability of snubbers. It is not designed to be used as a testing supplement to a more NAPS Unit 2

comprehensive program such asSection XI. The integration of Section XI and ISTD into an effective, coherent examination and testing program along with the required change to the TRM results in a significant amount of administrative activity without a compensating increase in safety.

Revising the TRM to reference only the ISTD document is in itself an administrative activity with little if any impact on safety and quality. Many of the requirements that would need to be removed from the TRM are very similar if not identical to the requirements being added by ISTD. Virginia Electric and Power Company (Dominion) proposes that the following alternative approach avoids this unnecessary administrative impact and still provides a means to accomplish the examination and testing required by Section XI and regulation.

The current testing and examination requirements of TRM Section 3.7.5 and the I additional visual examination requirements of the approved Section XI edition have formed the basis of the North Anna Unit 2 inservice examination/testing program for snubbers for the past IS1 interval. The use of this program had the approval of the NRC and is essentially the same as the program for examination and testing described in ISTD for inservice inspection.

Revision 1 of this relief request permits a C value of one to be utilized in the sampling formula of the TRM. The change from C=2 to C=l is desirable to take advantage of the historically low number of snubber failures experienced at North Anna. There has not been more than one failure from the required surveillance test group during any inspection cycle since 1992. The C value establishes the initial sample size, and when exceeded, establishes the size for the expanded snubber functional test group.

To demonstrate that reducing the allowable number of small bore snubber functional test failures from two to one would continue to provide an adequate degree of testing, a comparison of the current TRM formula to the ASME OMa (ISTD) formula [ASME OMa Code - 1995 w/l996 Addenda, Subsection ISTD Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants] has been performed assuming similar failure rates.

The current formula used in TRM Section 3.7.5 to determine the initial number of small bore snubbers to be functionally test each cycle is as follows At least once per 18 months during shutdown, a representative sample of small bore snubbers which follows the expression 35[1 + C/2] where C=2 is the allowable number of small bore snubbers not meeting the acceptance criteria selected by the operator, shall be functionally tested either in-place or in a bench test.

The ASME Code OMa uses two different formulas for establishing the number of snubbers to be initially functionally tested. The determination of which plan to NAPS Unit 2

use is determined by the number of snubbers installed in the station. North Anna 2 has less than 370 snubbers and therefore the 10% plan is the preferred plan and will be used for comparison to the TRM formula.

The equation used in the TRM to define expanded sample size is 35( 1 + C/2)(2/(C + l))*(A-C) where C is the allowable number of functional failures (currently equal to two)

A is the total number of functional failures in the initial sample size.

This equation is used when A exceeds C. Three functional test failures are required before an expanded sampling happens with C=2. With C=l the number of functional test failures required before expanded sampling begins will change to two.

The TRM is based on guidance given in NUREG 0452, Standard Technical Specifications for Westing house Pressurized Water Reactors, Revision 3 issued Fall 1980. NUREG-0452, Section 4.7.9 states in part The value C will be arbitrarily chosen by the applicant and incorporated into the expressions for the representative sample and for the resample prior to the issuance of the Technical Specifications. The TRM establishes a C to account for a certain number of failures before the testing population has to be expanded. This builds a failure rate into the group to be tested each outage before scope expansion would be required. The Code does not concern itself with this built in failure rate.

It is only concerned with testing an adequate number of snubbers to satisfy safety requirements.

ASME OMa Code (subsection ISTD 7.9.2) states that the additional sample size shall be at least one-half the size of the original sample. So the total number of snubbers to be tested, including initial test group, is N 2 0.1 n + C(O.l n/2)

N is the total number of snubbers to be tested, n is Total number of snubbers in defined test group plan, and C is the number of unacceptable snubbers found through functional testing.

where Reviewing the ASME OMa formula it can be seen that the Code does not define a pre-set number of allowable failures as the TRM does. The Code only requires that a minimum number of snubbers be tested based on the population [the O.ln factor] and an additional number of snubbers be tested for scope expansion based on the number found inoperable by testing [the C(0.1n/2) factor].

Substituting the number of snubbers for Unit 2, this formula reduces to:

Unit 2 N 2 36.2 + 18.1C NAPS Unit 2

The initial sizes and expanded sample sizes once the allowable number of functional test failures is exceeded is provided for comparison in the table below.

I A = 2 I

70 I

106 I

73 TRM formula I ASME OMa Code values 1

Functional test failures A = 3 (same values both units)

C=l value) c=2 (proposed Unit 2 102 158 91 (current value)

Functional test failures A = 3 A = 2 A = l A = O (same values both units)

C=l c=2 (proposed Unit 2 value)

(current value) 102 158 91 I

70 106 73 I

70 53 55 I

70 53 37 I

A = l A = O 70 53 55 70 53 37 I (Note: the value A or functional test failures as defined by the TRM would be equivalent to the value C in the ASME OMa Code formula.)

I I

I I

From the above table it can be seen that the TRM formula with C=2 (current value) or C=l (proposed value), will require testing of essentially the same or more snubbers than the ASME OMa Code.

The comparison in the table demonstrates that changing the value of C in the TRM formula will continue to provide an adequate degree of testing when compared to the ASME OMa Code.

Based on the above snubber testingkample size comparison Dominion believes that the proposed TRM Section 3.7.5 (C=l ) functional testing requirements will continue to provide an acceptable level of quality and safety for inservice testing of snubbers. Additionally, the continued administration of a program based on the TRM and Section XI requires only minimal administrative change activity.

However, to satisfy the preservice examination and testing requirements intended by Section XI, additional examination and testing activity is required beyond the above proposal for inservice snubber testing activities. Therefore, Dominion proposes that the inclusion of the examination and testing requirements contained in ASME OMa Code paragraphs ISTD 4, Preservice Examination (excluding paragraph 4.3), and ISTD 5, Preservice Operability Testing into the current snubber surveillance program provides an alternative with an acceptable level of safety and quality for the preservice examination and testing requirements.

The inclusion of these requirements into the snubber surveillance program achieves the preservice inspection requirements of Section XI.

Paragraph 4.3 is not proposed as it addresses requirements best suited for the initial heat up and cool down of the plant. It would be a burden to try and impose I NAPS Unit 2

these requirements on an operating plant such as North Anna Unit 2, which is I constructed with a sub-atmospheric containment.

As an alternative to the requirements of paragraph 4.3, North Anna Unit 2 will follow the guidance of I IWF-2220 (b) for systems that operate at a temperature greater than 200 degrees F. IWF-2220 (b) requires the Owner to perform an additional preservice examination on the affected component supports during or following the subsequent system heat up and cool down cycle unless determined unnecessary by evaluation. This examination shall be performed during operation or at the next refueling outage. ThisSection XI action has been accepted as providing acceptable quality and safety by the regulation for supports and North Anna Unit 2 believes it is acceptable as an alternative to paragraph 4.3 of ISTD.

No other requirements of ISTD will be implemented as part of this alternative.

IV.

PROPOSED ALTERNATIVE TO CODE REQUIREMENTS Dominion proposes as an alternative to Section XI requirements stated in Section I II of this request, a snubber examination and testing program comprised of the following elements:

1) The continued implementation of the surveillance requirements of TRM Section 3.7.5, Snubbers, (C=l) without change,

2) The implementation of the other applicable requirements of the ASME,Section XI Code, 1995 Edition with addenda up to and including the 1996 Addenda, unless specific approval has been obtained to do otherwise from the NRC pursuant to the requirements of 10 CFR 50.55a and the plants TRM. This will I include using the VT-3 visual examination method in IWA-2213 for preservice and inservice examinations,

3) The preservice examination and testing requirements of ISTD paragraph 4, Preservice Examination, excluding paragraph 4.3; and ISTD paragraph 5, Preservice Operability Testing, and

4) As alternative to paragraph 4.3 ISTD, for systems that operate at a temperature greater than 200 degrees F, North Anna Unit 2 will perform an I additional preservice examination on the affected snubbers during or following the subsequent system heat up or cool down cycle unless determined unnecessary by evaluation.

This examination may be performed during operation of the plant or at the next refueling outage. This is consistent with the requirements of IWF-2220 (b).

No other requirements of ISTD will be implemented as part of this alternative.

Dominion submits that the above alternative snubber program will continue to provide an acceptable level of quality and safety without the administrative changes that add little or no value to quality and safety, or the burden of NAPS Unit 2

performing snubber assessments under sub-atmospheric conditions. Therefore, having met the criteria of 10 CFR 50.55a(a)(3)(i) [note: a reference to (ii) was deleted in this revision since the original relief was approved under (i)], an authorization to implement the proposed alternative is requested for the remaining portion of the third inspection interval for North Anna Unit 2.

NAPS Unit 2 North Anna Power Station Units 1 and 2 Technical Requirements Manual Snubber Augmented lnservice Inspection Program Virginia Electric and Power Company (Dominion)

Snubbers 3.7.5 CONDITION 3.7 PLANT SYSTEMS REQUIRED ACTION COMPLETION TIME 3.7.5 Snubbers A.

One o r more snubbers i

noperabl e.

TR 3.7.5 Snubbers used on safety-re1 ated systems i n Tab1 es 3.7.5-2 and 3.7.5-3 shall be OPERABLE. Snubbers u t i l i z e d on non-safety related systems i n Tables 3.7.5-4 and 3.7.5-5 shall be OPERABLE i f a f a i l u r e o f t h a t snubber o r the f a i l u r e of a non-safety related system would have an adverse e f f e c t on any safety related system.

A. l. l Replace o r restore snubber(s) t o OPERABLE status.

APPLICABILITY:

According t o Tables 3.7.5-2 through 3.7.5-5.

ACT I ONS

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ N O T E Separate Condition entry i s allowed f o r each snubber.

72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (continued)

NAPS TRM 3.7.5-1 Rev 47, 09/23/04

ACT IONS CONDITION SURVEILLANCE A.

(continued)

FREQUENCY REQUIRED ACTION I n accordance w i t h the Snubber Augmented Inservi ce Inspection

~ [;:!7?3.7.5-

1)

A.1.2

---

NOTE---------

The engineering evaluation shall be conducted per the Functional Test description i n the snubber augmented i

nservi ce inspection program.

Determi ne, v i a engineering evaluation, t h a t the supported component remains capable o f meeting the design service.

OR A.2 Declare the supported system inoperable.

Snubbers 3.7.5 COMPLETION TIME 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 72 hours TSR 3.7.5.1 Verify snubbers are OPERABLE by inspection and t e s t i n g i n accordance with the Snubber Augmented Inservice Inspection Program (Table 3.7.5-1).

NAPS TRM 3.7.5-2 Rev 47, 09/23/04

Snubbers 3.7.5 Table 3.7.5-1 (page 1 o f 4)

Snubber Augmented Inservice Inspection Program NOTE:

a. Visual Inspection Snubbers are categorized as accessible or inaccessible during reactor operation. Each of the categories (accessible o r inaccessible) may be inspected independently according t o the schedule determined by the following table and the visual inspection interval for each type of snubber shall be determined based upon the c r i t e r i a provided i n that table.

As used in t h i s requirement, "type of snubber" shall mean snubbers of the same design and manufacturer, irrespective of capacity.

Snubber Visual Inspection Interval Number of Unacceptable Snubbers Population Column A Column B Column C o r Category Extend Interval Repeat Interval Repeat Interval (Notes 5 and 6)

(Notes 1 and 2)

(Notes 3 and 4)

(Notes 4 and 6) 1 80 100 150 200 300 400 500 750 1000 or more 0

0 0

0 2

5 8

12 20 29 0

0 1

3 5

12 18 24 40 56 1

2 4

8 13 25 36 48 78 109 NOTE 1: The next visual inspection interval f o r a snubber population o r category size shall be determined based upon the previous inspection interval and the number of unacceptable snubbers found during the interval. Snubbers are categorized, based on their accessibility during power operation, as accessible o r inaccessible. These categories may be examined separately o r jointly. However, the 1 icensee must decide upon that categorization and document that decision before any inspection and shall use that decision as the basis for determining the next inspection interval for that cat ego ry.

NOTE 2: Interpolation between population o r category sizes and the number o f unacceptable snubbers is permissible. If the results of the interpolation i s a fractional value, round off the results t o the next lower integer t o establish the applicable number of unacceptable snubbers f o r each column.

NOTE 3: If the number o f unacceptable snubbers is equal t o o r less than the number i n Column A, the next inspection interval may be twice the previous interval b u t not greater than 48 months NOTE 4: If the number of unacceptable snubbers i s equal to o r less than the number in Column B b u t greater than the number i n Column A, the next inspection interval shall be the same as the previous interval.

NAPS TRM 3.7.5-3 Rev 47, 09/23/04

Snubbers 3.7.5 Table 3.7.5-1 (page 2 o f 4)

Snubber Augmented Inservice Inspection Program NOTE 5: If the number of unacceptable snubbers i s equal to o r greater than the number in Column C, the next inspection interval shall be two-thirds of the previous interval. However, i f the number of unacceptable snubbers is less than the number i n Column C b u t greater than the number i n Column B, the next interval shall be reduced proportionally by interpolation, that i s, 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 i n Column B t o the difference i n the numbers i n Columns B and C.

NOTE 6: The provisions of TSR 3.0.2 are applicable for a l l inspection intervals up t o and C.

including 48 months.

b. Visual Inspection Acceptance Criteria Visual inspections shall verify that (1) the snubber has no visible indications of damage or impaired OPERABILITY, (2) attachments t o the foundation or supporting structure are secure, (3) fasteners f o r the attachment of the snubber to the component and t o the snubber anchorage are functional, and (4) i n those locations where snubber movement can be manually induced without disconnecting the snubber, that the snubber has freedom of movement and i s not frozen up.

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, providing that (1) the cause of the rejection i s clearly established and remedied f o r that particular snubber and f o r other snubbers, irrespective of type, that may be generically susceptible, and (2) the affected snubber shall be functionally tested in the as found condition and determined OPERABLE per sections d and e of this table.

All snubbers found connected to an inoperable common hydraulic fluid reservoir shall be counted as unacceptable f o r determining the next visual inspection interval. A review and evaluation shall be performed and documented to justify continued operation with an unacceptable snubber. If continued operation cannot be justified, the snubber shall be declared inoperable and the ACTION requirements shall be met.

When hydraulic snubbers which have uncovered fluid ports are tested for OPERABILITY, the t e s t shall be performed by starting w i t h the piston a t the as-found setting and extending the piston rod in the tension mode direction. Snubbers which have been determined t o be inoperable as a result of unexpected transients, isolated damage, o r other random events, and cannot be proven OPERABLE by functional testing for the same reasons, shall not be counted i n determining the next visual inspection period when the provision i n Section c of this table that failures are subject to an engineering evaluation of component structural integrity has been met and equipment has been restored t o an OPERABLE s t a t e via repair and/or replacement as necessary.

Functional Tests A t least once per 18 months during shutdown, a representative sample of small bore snubbers which follows the expression 35[1 + c/2] where c = 2 i s the allowable number of small bore snubbers not meeting the acceptance c r i t e r i a selected by the operator, shall be functionally tested either in-place or in a bench test. For each number of small bore snubbers above "c" which does not meet the functional t e s t acceptance c r i t e r i a for Sections d and e of t h i s table, a!

additional sample selected according to the expression 35(1 + c/2)(2/(c + 1)) (a - c) shall be functionally tested, where "a" is the total number of small bore snubbers found inoperable during the functional testing of the representative sample.

NAPS TRM 3.7.5-4 Rev 47, 09/23/04

Snubbers 3.7.5 Table 3.7.5-1 (page 3 o f 4)

Snubber Augmented Inservice Inspection Program Functional testing shall continue according to the expression b[35(1 + c/2) (2/(c + l))']

where "b" i s the number of snubbers found inoperable in the previous re-sample, until no additional inoperable snubbers are found within a sample or until a l l small bore snubbers have been functionally tested.

A t l e a s t once per 18 months during shutdown, 10% of the large bore snubbers (snubbers greater than 50 kips) shall be functionally tested either i n place, in a full snubber bench t e s t, or in a snubber valve block bench test. For each large bore snubber that does not meet the functional t e s t acceptance c r i t e r i a of Section d of t h i s table, an engineering evaluation i s required to determine the failure mode. If the failure i s determined t o be generic, an additional 10% of that type of snubber shall be functionally tested. If the failure i s determined t o be non-generic, an additional 10%

of that type of snubber will be tested during the next functional t e s t period.

The representative sample selected for functional testing shall include the various configurations, operating environments and the range of size and capacity of snubbers.

A t least 25% of the snubbers i n the representative sample shall include snubbers from the following three categories:

1. The f i r s t snubber away from each reactor vessel nozzle.

2. Snubbers w i t h i n 5 feet of heavy equipment (valve, pump, turbine, motor, etc.).

3. Snubbers w i t h i n 10 feet of the discharge from a safety relief valve.

Snubbers that are "Especially Difficult t o Remove" o r in "HighaRadiation Zones During Shutdown" shall also be included in the representative samples. Accessible and inaccessible snubbers may be used jointly o r separately as the basis for the sampling plan.

In addition to the regular sample, snubbers which failed the previous functional t e s t shall be retested during the next t e s t period. If a spare snubber has been installed in place of a failed snubber, then both the failed snubber ( i f i t is repaired and installed i n another position) and the spare snubber shall be retested. Test results of these snubbers may not be included i n the re-sampling.

If any snubber selected for functional testing either f a i l s t o lockup o r f a i l s t o move, i.e., frozen in place, the cause will be evaluated and i f caused by manufacturer o r design deficiency all snubbers of the same design subject t o the same defect shall be functionally tested. This testing requirement shall be independent of the requirements stated above for snubbers not meeting the functional t e s t acceptance c r i t e r i a.

For the snubber(s) found inoperable, an engineering evaluation shall be performed on the components which are supported by the snubber(s). The purpose of t h i s engineering evaluation shall be to determine i f the components supported by the snubber(s) were adversely affected by the inoperability of the snubber(s) in order t o ensure that the supported component remains capable of meeting the design service.

(a) Permanent o r other exemptions from functional t e s t i n g f o r individual snubbers i n these categories may be granted by the Comnission only i f a j u s t i f i a b l e basis f o r exemption i s presented and/or snubber l i f e destructive t e s t i n g was performed t o q u a l i f y snubber OPERABILITY f o r a l l design conditions a t e i t h e r the completion o f t h e i r fabrication o r a t a subsequent date.

NAPS TRM 3.7.5-5 Rev 47, 09/23/04

Snubbers 3.7.5 Table 3.7.5-1 (page 4 o f 4)

Snubber Augmented Inservice Inspection Program

d. Hydraulic Snubbers Functional Test Acceptance Criteria The hydraulic snubber functional t e s t shall verify that:

1. Activation (restraining action) i s achieved within the specified range of velocity or acceleration in both tension and compression.

2. Snubber bleed, o r release rate, where required, i s within the specified range in compression or tension. For snubbers speci f i cal l y requi red t o not displace under continuous load, the ability of the snubber to withstand load without displacement shall be verified.

e. Mechanical Snubbers Functional Test Acceptance Criteria The mechanical snubber functional t e s t shall verify that:

1. The force that i n i t i a t e s free movement of the snubber rod in either tension o r compression i s less than the specified maximum drag force. Drag force shall not have increased more than 50% since the l a s t functional test.

2. Activation (restraining action) i s achieved within the specified range of veloc o r acceleration in both tension and compression.

3. Snubber release rate, where required, i s within the specified range in compress on o r tension. For snubbers specifically required not to displace under continuous load, the a b i l i t y o f the snubber t o withstand load without displacement shall be veri f i ed.

f. Snubber Service L i fe Monitoring A record of the service l i f e of each snubber, the date a t which the designated service l i f e comnences and the installation and maintenance records on which the designated service l i f e i s based shall be maintained.

A t least once per 18 months, the installation and maintenance records for each required snubber defined i n 3.7.10 shall be reviewed t o verify that the indicated service l i f e has not been exceeded o r will not be exceeded prior to the next scheduled snubber service l i f e review. If the indicated service l i f e will be exceeded prior to the next scheduled snubber service 1 i fe review, the snubber service 1 i f e shall be re-eval uated o r the snubber shall be replaced o r reconditioned so as t o extend its service l i f e beyond the date of the next scheduled service l i f e review. T h i s re-evaluation, replacement or reconditioning shall be indicated i n the records.

NAPS TRM 3.7.5-6 Rev 47, 09/23/04