Text

Fifth Ten-Year Interval Snubbers Testing Program
	ML14353A061
Person / Time
Site:	Prairie Island
Issue date:	12/18/2014
From:	Davison K; Northern States Power Co, Xcel Energy
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	L-PI-14-131
	Download: ML14353A061 (29)
	v • d • e

Xcel Energy DEC 18 2014 L-PI-14-131 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 Fifth Ten-Year Interval Snubbers Testing Program Pursuant to the guidance of the American Society of Mechanical Engineers (ASME) OM Code, 2004 Edition, Code for Operation and Maintenance of Nuclear Power Plants, Section ISTA-3200(a), Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits for NRC information the fifth ten-year interval for the Prairie Island Nuclear Generating Plant (PINGP),

Units 1 and 2, snubbers testing program. The PINGP fifth ten-year interval begins December 21, 2014.

The fifth ten-year interval snubbers program is Enclosure 1 to this letter. The program was developed to satisfy the snubbers preservice and inservice testing and examination requirements of the ASME OM Code 2004 Edition through 2006 Addenda.

If there are any questions or if additional information is needed, please contact Mr. Ben Hammargren at 651-267-6830.

1717 Wakonade Drive East

Welch, Minnesota 55089-9642 Telephone: 651.388.1121

Document Control Desk Page 2 Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.

J~~C>>._c Kevin Davison Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosures (1) cc: Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC

ENCLOSURE 1 Prairie Island Nuclear Generating Plant Snubber Examination and Functional Test Program H20, Revision 10 26 pages follow

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 1 of 26 INFORMATION USE

Procedure may be performed from memory.

User remains responsible for procedure adherence.

Procedure should be available, but not necessarily at the work location.

PORC REVIEW DATE: OWNER: EFFECTIVE DATE NR D. Schantzen 12/15/14

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 2 of 26 TABLE OF CONTENTS Section Title Page 1.0 PURPOSE ............................................................................................................ 3

2.0 REFERENCES

..................................................................................................... 3 3.0 DEFINITIONS ....................................................................................................... 4 4.0 RESPONSIBILITIES ............................................................................................. 7 5.0 PROGRAM REQUIREMENTS ........................................................................... 11 LIST OF TABLES Table 1 Snubber Visual Examination Interval ............................................................ 26

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 3 of 26 1.0 PURPOSE 1.1 This document describes the Prairie Island Nuclear Generating Plant Snubber Program for the fifth 10-year interval. The ASME Code for this interval according to 10CFR 50.55a is ASME OMa Code 2004, 2006 Addendum. The program is developed to satisfy the requirements of ISTD and to assure that Code Class 1, 2, 3 and MC component snubbers operate when called upon.

1.2 The implementation date for the 5th ten year interval program is December 21, 2014 for Unit 1 & Unit 2.

1.3 This procedure covers the preservice and inservice examinations and testing requirements, documentation requirements and methodology for the evaluation, resolution and disposition of safety related snubbers which have been identified as inoperable. The intent of this procedure is to provide uniform engineering approach to maintenance, examination and testing of snubbers and to effect resolution of snubbers found to be inoperable.

2.0 REFERENCES

2.1 ASME Code for Operation and Maintenance of Nuclear Power Plants- 2004 Edition through 2006 Addenda 2.2 10CFR 50.55a Codes and Standards 2.3 Technical Specification LCO 3.0.8 2.4 NUTECH Basic Engineers Snubber Evaluation Program, September 1, 1979 2.5 NRC Commitments 2.5.1 P-448, Snubber Fluid Monitoring 2.5.2 P-449, Snubber Back Up Ring Changeout 2.5.3 P-450, ITT Grinnell Replacement Snubber Rebuild

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 4 of 26 2.6 Surveillance Procedures 2.6.1 SP 1171 [2171], Tech Spec Shock Suppressor Check 2.6.2 TP 1535 [2535], Non Tech Spec Shock Suppressor Check 2.6.3 SP 1225 [2225], Snubber Functional Tests 2.7 Implementing Procedures 2.7.1 045, Snubber Test Stand Operating Procedure 2.7.2 045.2, Testing of Replacement Snubbers Prior to Installation 2.7.3 045.3, Steam Generator 900 KIP Snubber Maintenance Procedure 2.7.4 045.4, Snubber Removal and Installation Procedure 2.7.5 045.5, Snubber As Found Functional Test Procedure 2.8 Site Engineering Manual, Section 3.2.1.2 "Specification for the Design of Pipe Supports" 2.9 5AWI 3.12.2, ASME Repair/Replacement Program 3.0 DEFINITIONS The following definitions are provided to ensure a uniform understanding of selected terms used in this procedure.

3.1 activation - the change of condition from passive to active, in which the snubber resists rapid displacement of the attached pipe or component.

3.2 application-induced failures- failures resulting from environmental conditions or application of the snubber for which it has not been designed or qualified.

3.3 defined test plan group (DTPG) - a population of snubbers selected from which samples are selected for testing.

3.4 design or manufacturing failure -failures resulting from a potential defect in manufacturing or design that give cause to suspect other similar snubbers.

This includes failures of any snubber that fails to withstand the environment or application for which it was designed.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 5 of 26 3.5 diagnostic testing - testing to determine the cause or mechanism associated with failure, degradation, or performance anomaly of a snubber.

3.6 drag force -the force that will sustain low-velocity snubber movement without activation throughout the working range of the snubber stroke.

3. 7 failure mode group (FMG) - a group of snubbers that have failed and those other snubbers that have similar potential for similar failure.

3.8 inaccessible snubbers- snubbers that are in a high radiation area or other conditions that would render it impractical for the snubbers to be examined under normal plant operating conditions without exposing plant personnel to undue hazards.

3.9 isolated failure- a failure which does not cause other snubbers to be suspect.

3.10 maintenance, repair, and installation-induced failures -failures that result from damage during maintenance, repair, or installation activities, the nature of which causes other snubbers to be suspect.

3.11 normal operating conditions - operating conditions during reactor startup, operating at power, hot standby, reactor cooldown, and cold shutdown.

3.12 operating temperature -the temperature of the environment surrounding a snubber at its installed plant location during the phase of plant operation for which the snubber is required.

3.13 operational readiness testing- measurement of the parameters that verify snubber operational readiness.

3.14 release rate- the rate of the axial snubber movement under a specified load after activation of the snubber takes place.

3.15 replacement snubber- any snubber other than the snubber immediately previously installed at a given location.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 6 of 26 3.16 service life - the period of time an item is expected to meet the operational readiness requirements without maintenance.

3.17 service life population -those snubbers for which the same service life has been established.

3.18 swing clearance - the movement envelope within which the snubber must operate without restriction from the cold installed position to the hot operating position.

3.19 test temperature - the temperature of the environment surrounding the snubber at the time of the test.

3.20 transient dynamic event failure- inability of a snubber to perform its intended function due to unanticipated transient dynamic event.

3.21 unacceptable snubbers -snubbers that do not meet examination or testing requirements.

3.22 unexplained failure -failure for which the cause has not been determined

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 7 of 26 4.0 RESPONSIBILITIES 4.1 Engineer Programs Manager The Manager Technical Programs Engineering is assigned overall responsibility for the administration and implementation of the lnservice Examination and Testing Program for Dynamic Restraints.

4.2 Supervisor Equipment Reliability Engineering Provides direction and approves Snubber Program initiatives and procedures.

4.3 Snubber Program Engineer 4.3.1 Ensures that program requirements are in compliance with the ASME OM Code Subsection ISTD, 10CFR 50.55a Codes and Standards, and Technical Specification LCO 3.0.8.

4.3.2 Implements the Snubber Program as defined in this procedure.

4.3.3 Prepares the snubber test schedule prior to each outage for both units.

4.3.4 Reviews the service life of all snubbers to ensure that snubbers are removed from service prior to exceeding service life. This review should be performed prior to each outage for both units. One aspect of service life is seal life and this information can be found in SP 1225 [2225] for various makes of seals.

4.3.5 Maintain the necessary qualifications to accomplish the Snubber Program tasks.

4.3.6 Developing and maintaining procedures for the examination and testing of snubbers.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 8 of 26 4.3.7 Ensuring that all required snubbers are maintained in an operable status and providing resolution and corrective action for operability issues resulting from visual examinations and functional testing.

4.3.8 Maintains lddeal SnubbWorks database computer program.

4.3.9 Coordinates visual examination in accordance with Surveillance Test Procedures and ASME Section XI.

4.3.10 Coordinates NDE visual services.

4.3.11 Responsibility for providing the lSI Engineer and the Authorized Nuclear lnservice Inspector summary test results of all visual examinations (VT-3) and inservice functional tests performed during each outage, as documented on SPs 1171 [2171], 1225 [2225], and TP 1535 [2535], within 60 days from startup for inclusion in the lSI Summary Report.

4.3.12 Responsibility for providing the lSI Engineer with a list of snubbers that the plant will be performing snubber functional testing at least 75 days prior to the outage.

4.3.13 Perform the periodic assessments required by the program health report.

4.3.14 Share and communicate industry events, etc., with other fleet plants.

4.3.15 Interface with the Maintenance Department as necessary to ensure:

A. Qualified personnel remove, test, refurbish, and reinstall snubbers.

B. Snubbers are tested in a clean environment.

C. Adequate facilities for refurbishing snubbers.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 9 of 26 4.3.16 Interface with other Engineering Department organizations as necessary to:

A. Evaluate snubber operability concerns associated with transient dynamic events.

B. Assist in snubber selection, sizing, and application for modifications and replacements.

C. Evaluate the potential effects on piping systems due to an inoperable snubber.

4.3.17 Coordinates with Operations in the event a snubber fails its test criteria and when removing/installing snubbers under procedure 045.4.

4.3.18 Reviews and evaluates completed functional test reports.

4.3.19 Reviews vendor test procedures.

4.4 Maintenance 4.4.1 Maintaining snubber test stand calibration during periods of use.

4.4.2 Evaluating and ensuring adequate inventory of spare parts required for maintenance of hydraulic snubbers.

4.4.3 Perform functional tests as specified in the Snubber Functional Test Program and ASME OM Code ISTD.

4.4.4 Responsibility for all work orders associated with plant snubbers.

4.4.5 Reviewing completed test reports.

4.4.6 Coordinating the evaluation of unacceptable snubber conditions.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 10 of 26 4.4.7 Evaluating test results.

4.4.8 Selecting and coordinating vendors to perform testing.

4.4.9 Reviewing vendor test procedures.

4.4.1 0 Maintains contract for functional test services.

4.5 Planning 4.5.1 Responsible for planning all Work Orders for snubber repair, replacement, or testing.

4.5.2 Responsible for reserving parts required for all Work Orders.

4.6 Warehouse 4.6.1 Responsible for maintaining adequate stock levels based on historical needs and SIRs.

4.6.2 Ensure Maintenance is notified of snubbers stocking needs for outage replacements. Notification should be provided with sufficient lead time to allow Maintenance time to rebuild snubbers to meet demand.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 11 of 26 5.0 PROGRAM REQUIREMENTS 5.1 Design and Operating Information When in operation, a snubber is to move freely with thermal motions of the piping system, giving no resistance to this movement. A snubber must allow thermal movement of the piping while acting quickly to restrain piping subjected to seismic or other shock to the system activity. During this seismic or shock to the system, the snubber is required to lock-up and take the full rated-load of the snubber. It is in the locked up state that the snubber acts as a rigid restraint to prevent damage from excessive line movement. The rate of snubber movement at one end with respect to the other after activation is dependent on load and increases as load increases.

However, during most seismic events (3-12Hz), the frequency of motion (cyclic) does not allow for any bleed rate.

Prairie Island uses four manufacture r types of hydraulic snubbers and zero mechanical snubbers. The types are: Paul Monroe 2200, 2300 & 2400; ITT Grinnell Fig. 200/201; Basic Engineer BE 41 0; and McDowell-W ellman 900k Steam Generator snubbers. Majority of the hydraulic snubber population at Prairie Island is made up of Basic Engineer BE 410.

5.1.1 Generally the Tech Manual should contain information such as: snubber operating and maintenance instructions; spare and replacement parts list; design drawings showing snubber ratings and dimensions and material specifications. A Tech Manual SHALL be established for all makes of snubbers used on site.

5.1.2 Information on snubber velocity acceptance criteria for specific locations is contained in D45, "Snubber Test Stand Operating Procedure". The values given in this maintenance procedure are based on Table 3.2 of Appendix 1 of the NUTECH "Basic Engineers Snubber Evaluation Program" document, which calculates 50 ipm for activation and release rate on many snubbers as a conservative upper limit. Therefore, the required activation and release rate for all snubbers SHALL be less than 50 ipm, except as specified in Table 2 and Table 3 of D45. Release rates SHALL always be greater than 0 ipm.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

H20 SNUBBER EXAMINATION AND H FUNCTIONAL TEST PROGRAM REV: 10 Page 12 of 26 A. To be acceptable, a snubber SHALL meet all of the following performance test criteria:

1. activation is within the specified range;

2. release rate is within the specified range.

If the device is required to resist all displacement after activation, the resistance to displacement must be exhibited; and

3. breakaway and/or drag force does not exceed specified quantities in both directions.

B. When a snubber is determined to be unacceptable as a result of inservice operability testing, the snubber SHALL be declared out of service and corrective action SHALL be completed within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or the system affected by the snubber SHALL be declared out of service and the applicable LCO CONDITION entered. The following specific action SHALL be taken:

1. Components/systems whose snubbers fail the test SHALL be examined to ensure that the supported component(s) has (have) not been impaired. This SHALL be documented in accordance with FP-PA-ARP-01, CAP Action Request Process.

2. Operability requirements for specific locations may be calculated based on design loads, seismic displacements, and maximum pipe thermal expansion velocity. Operability testing requirements based on these values SHALL be met for the snubber.

3. Operability determinations SHALL be conducted by operations and documented in accordance with the requirements of FP-OP-OL-01, Operability Functionality Determination.

4. Past operability determinations SHALL be conducted by Engineering and documented in accordance with the requirements of FP-OP-OL-01, Past Operability Evaluation.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 13 of26 5.1.3 Examinations and tests SHALL be performed in accordance with written procedures.

5.1.4 The results of examination and test data SHALL be documented and SHALL include the following, as a minimum:

A. serial number, type and unique location identification of the snubber; B. date of test or examination; C. reason for test or examination (e.g., post-maintenance, routine inservice test or examination, establishing reference values, etc.);

D. test or examination procedure used; E. identification of test equipment used; F. calibration records; G. values of measured parameters; H. comparison with allowable ranges of test and examination values, and analysis of deviations; I. requirement for corrective action; and J. printed (or typed) name and signature of the person(s) responsible for conducting and analyzing the test and examination.

5.1.5 Personnel who perform the visual examination SHALL be NSP certified VT-3.

5.1.6 All instruments and test equipment used in performing the inspection program SHALL be calibrated in accordance with 5AWI 3.14.0 "Calibration and Control of Inspection, Measuring and Test Equipment, and In-Process Instrumentation and Devices".

5.1. 7 All snubbers to be installed in the plant SHALL be functionally tested prior to installation.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

H20 SNUBBER EXAMINATION AND H FUNCTIONAL TEST PROGRAM REV: 10 Page 14 of 26 5.1.8 It is recognized that there may be differences between the operating conditions in which the snubber is intended to be installed and the conditions under which a snubber is tested. In such cases, correction factors SHALL be established and test results SHALL be correlated to the operating conditions that the snubber is anticipated to be exposed to when installed.

5.1.9 At this time Prairie Island has no situation that requires the use of correction Factors. The use of corrections Factors should be considered for plant configuration changes.

5.2 Visual Examination 5.2.1 The examinations required by the Snubber Visual Examination Program for the 10% sample plan will be performed using FP-PE-NDE-530 "Visual Examination, VT-3".

5.2.2 Visual examinations of snubbers should be performed as soon as possible at the onset of the outage to prevent failures from the increased maintenance in the plant.

5.2.3 Visual examinations SHALL verify that there are no: (1) loose fasteners, or members that are corroded or deformed; (2) disconnected components or other conditions that might interfere with the proper restraint of movement.

Snubbers evaluated to be incapable of restraining movement SHALL be classified unacceptable.

5.2.4 Snubber installations SHALL NOT restrain thermal movement to an extent that unacceptable stresses could develop in the snubber, the pipe, or other equipment that the snubber is designed to protect or restrain. This requirement is satisfied if no indication of binding, misalignment, or deformation of the snubber is observed.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 15 of 26 5.2.5 Snubbers SHALL be free of defects that may be generic to particular designs as may be detected by visual examination. For example, fluid supply or content for hydraulic snubbers SHALL be observed. An observation that the fluid level is equal to or greater than the minimum specified amount that is sufficient for actuation at its operating extension is considered to satisfy this requirement. If the fluid is less than the minimum amount, the installation SHALL be identified as unacceptable, unless a test establishes that the performance of the snubber is within specified limits.

5.2.6 A snubber that requires further evaluation or is classified as unacceptable during inservice examination may be tested in accordance with the requirements of this procedure. Results that satisfy the operational readiness test criteria of this procedure SHALL be used to accept the snubber, provided the test demonstrates that the unacceptable condition did not affect operational readiness by verifying 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 displacement SHALL be verified.

All hydraulic snubbers found connected to an inoperable common hydraulic fluid reservoir SHALL be counted as unacceptable for determining the next examination 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 applicable requirements SHALL be met.

5.2.7 To be acceptable, a snubber SHALL be capable of performing its design function as installed. There may be conditions present which are undesirable but which do not render the installed snubber inoperable.

These, as well as any unacceptable snubbers, are subject to corrective action.

To be acceptable, the snubber installation must meet all of the following requirements. If it fails to meet any one of these requirements, it SHALL be identified as unacceptable.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 16 of 26 A. Snubbers SHALL be installed so that they will carry the specified load. Visual observation of loose fasteners, deformed members, or detection of disconnected components requires the identification of the installation as unacceptable.

B. Snubbers SHALL be installed in such condition that they do not restrict the thermal movement to the extent that unacceptable overstressing could develop in the pipe or other equipment that the installation is designed to protect or restrain. Misalignment, deformation, or a jammed condition can result in such a situation.

Restrictive forces suspected to be greater than those allowable for the piping or equipment require the identification of the installation as unacceptable. If no indication of binding is observed and the snubber is free to pivot at the pinned connections, the provisions of these requirements are considered to have been satisfied.

C. Special features required for the actuation of the snubber which can be visually verified are to be observed. Fluid supply or content for hydraulic snubbers is to be observed. If the fluid level is not acceptable, (no measurable fluid in the snubber reservoir), the installation is to be identified as unacceptable until the snubber may be functionally tested to establish snubber operability. Observation that the fluid level is equal to or greater than a specified amount which is sufficient for actuation at its operating extension is considered to satisfy the provisions of this requirement for hydraulic snubbers.

D. Snubber orientation, piston rod extension, size of snubber and attachments SHALL be in accordance with the snubber design. This includes the angular misalignment restrictions of +/- 5% between clevis and paddle.

E. In addition, the following criteria must be met:

1. Adequate fluid level in reservoir.

2. Breather vent in upright position.

3. No visible indications of damage or impaired operability.

4. No fluid leakage on shaft, seals, joints, coupling, or in area (on floor).

5. Rotating bearing connections provide freedom of movement.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 17 of 26 5.2.8 If any one of the above operability requirements is not met, specific action SHALL be taken within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . Procedure 045.4, "Snubber Removal and Installation Procedure" provides a table where the time of removal and installation is recorded to ensure the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months time limit is not exceeded.

5.2.9 Preservice Visual Examination SHALL be performed on all snubbers that are installed into the plant.

A. This visual exam SHALL, as a minimum, verify the following:

1. No visible signs of damage or impaired operability exist as a result of storage, handling, or installation;

2. The snubber load rating, location, orientation, position setting, and configuration (e.g., attachments and extensions) are in accordance with design drawings and specifications.

Installation records (based on physical inspections) of verification that the snubbers were installed according to the design drawings and specifications SHALL be acceptable in meeting this requirement;

3. Adequate swing clearance is provided to allow snubber movement;

4. If applicable, fluid is at the recommended level, and fluid is not leaking from snubber system;

5. Structural connections, such as pins, bearings, studs, fasteners, lock nuts, tabs, wire, and cotter pins, and installed correctly.

B. If the period between the preservice examination and the initial system preoperational test exceeds 6 months, reexamination SHALL be performed in accordance with ISTD-411 O(a), ISTD-411 O(d), and ISTD-4110(e).

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 18 of 26 5.3 Functional Testing 5.3.1 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 test acceptance criteria in 5.1.2, an additional five 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. Results SHALL be documented on D45.5, "Snubber As Found Functional Test Procedure".

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

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.

If any snubber selected for functional testing fails, the cause SHALL be evaluated. This testing is in addition to the regular sample and specified re-samples.

5.3.2 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 displacement SHALL be verified.

C. Drag Force is within specific limits both in tension and compression.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 19 of 26 5.3.3 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 affected by the inoperable snubber(s) to ensure that the components remain capable of meeting the designed service. All snubbers specified by engineering evaluation SHALL also be functionally tested. This evaluation SHALL be documented on SP 1225 [2225].

If the piping system is operated in a normal manner (no accident), the only adverse effects upon components of the piping system from inoperable snubbers are those caused by failure of the snubber to allow the pipe to thermally grow or in the case of a relief valve support, failure of the snubber to support the relief valve during a discharge or a stress imposed upon the relief valve piping during discharge due to excessive bleed rate and consequent ratcheting action. The engineering evaluation SHALL address these effects. The author of the evaluation should reference the appropriate piping analysis printout and/or engineering evaluation provided by Fluor Power Service, Inc. or other qualified sources.

5.3.4 Test Plans A The Snubber Program Engineer or designee determines the snubbers to be tested as required by the ASME OM Code, Subsection ISTD. As a minimum, a 10% sample from each DTPG will be selected for functional testing each outage. This sample will be determined prior to each refueling outage for both units.

[Note: Fractional numbers from the 10% sample will be rounded-up].

1. DTPG's are a population of snubbers selected for testing in accordance with the 10% plan.

2. As practicable, the sample SHALL include representation from the DTPG based on the significant features (i.e., the various designs, configurations, operating environments, sizes, and capacities) and based on the ratio of the number of snubbers of each significant feature, to the total number of snubbers in the DTPG. Selection of the representative snubbers SHALL be random.

3. The sample SHALL be generally representative as specified in paragraph 5.3.4A.2. Above, but may be selected from snubbers concurrently scheduled for seal replacement or other similar activity related to service life monitoring.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 20 of 26 B. The Snubber Program Engineer or designee determines the snubbers to be tested as required by the ASME OM Code, Subsection ISTD for service life monitoring.

1. Service life SHALL be evaluated at least once each fuel cycle for both units, and increased or decreased, if warranted.

2. If the evaluation from 5.3.48.1 indicates that service life will be exceeded before the next scheduled system or plant outage, one of the following actions SHALL be taken:

a The snubber SHALL be replaced with a snubber for which the service life will not be exceeded before the next scheduled system or plant outage.

b Technical justification SHALL be documented for extending the service life to or beyond the next scheduled system or plant outage.

c The snubber SHALL be reconditioned such that its service life will be extended to or beyond the next scheduled system or plant outage.

3. The service life evaluation, for hydraulic snubbers that are tested without applying a load to the snubber piston rod, SHALL consider the results of the following requirements.

a Monitoring the particulate, viscosity, and moisture content of one or more samples of hydraulic fluid from the main cylinder of the snubber. This may be accomplished using snubbers of the same design in a similar or more severe environment.

b Monitoring of piston seal, piston rod seal, and cylinder seal integrity. If seal integrity is monitored by pressurization, pressures less than the snubber's rated load pressure may be used. Minimum pressure allowed SHALL be specified by the Owner.

5.3.5 Snubbers identified as having been exposed to a transient dynamic event will be either hand stroked or functionally tested within 6 months of the event. While a failure of one of these snubbers does not require a sample expansion, more functional testing may be required based upon engineering analysis of the dynamic event and the resultant failure.

H PROCEDURE PRAIRIE ISLAND NUCLEAR GENERATING PLANT NUMBER:

H20 SNUBBE R EXAMINATION AND H FUNCTIONAL TEST PROGRAM REV: 10 Page 21 of 26 5.3.6 Snubbers SHALL NOT be adjusted, maintained, or repaired before a test specifically to cause the snubber to meet the test requirements.

5.3.7 In addition to the regular sample and specified re-sampling, snubbers placed in the same location as snubbers that failed the previous inservice operational readiness test SHALL be retested at the time of next operational readiness testing unless the cause of the failure is clearly established and corrected.

5.3.8 The installation and maintenance records for each snubber SHALL be reviewed at least once every 24 months to verify that the indicated service life will not be exceeded prior to the next scheduled snubber service life review. If the indicated service life will be exceeded, the snubber service life SHALL be re-evaluated 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 indicated in the records.

5.3.9 Addressing Failures The Snubber Program Engineer or designee SHALL be notified as soon as possible of any snubber failures. The CAP process will be used to document all functional test failures. In addition, snubbers that do not meet the test requirements SHALL be evaluated to determine the cause of the failure. The evaluation SHALL include a review of information related to other unacceptable snubbers found during the same test campaign. The evaluation results SHALL be used, as applicable, to determine FMGs to which snubbers should be assigned. Additional justifying information should be used to assign snubbers with failures previously identified as unexplained or isolated to an appropriate FMG.

A. If additional tests are required due to failures, the contingency snubbers will be identified on the CAP. Snubbers that do not meet the acceptance criteria for functional testing SHALL be evaluated to determine the cause of the failure to determine corrective actions.

B. The cause of an inoperable snubber condition can often be easily determined by external examination, such as the existence of paint on moving parts. Visual examinations and measurements, coupled with the knowledge of snubber operational details, are usually sufficient to determine the cause of the failure.

H PROCEDURE PRAIRIE ISLAND NUCLEAR GENERATING PLANT NUMBER:

H20 SNUBBE R EXAMINATION AND H FUNCTIONAL TEST PROGRAM REV: 10 Page 22 of 26 C. However, in some cases, the snubber will require disassembly to determine the cause of failure and whether a part broke from an overload or fatigue, or broke in tension or compression, etc.

Additional investigation is usually required to determine what caused this defect to develop.

5.3.10 Failed snubbers may be assigned to one or more of the following Failure Mode Groups (FMG's):

A. Design or Manufacturing B. Application Induced C. Maintenance, Repair, or Installation D. Transient Dynamic Event 5.3.11 When a snubber is assigned to more than one FMG, it SHALL be counted in each of those FMGs and SHALL be included in corrective action for each of those FMGs.

5.3.12 Corrective actions for each FMG are provided below:

A. Design or Manufacturing and Application-Induced Failure Mode. The following corrective actions SHALL apply:

1. All snubbers in the FMG SHALL be replaced or modified. The replacement/modified snubbers SHALL be reclassified as acceptable and the applicable reexamination performed.

2. All unacceptable snubbers in the Application-Induced FMG SHALL be replaced or repaired to an acceptable condition and the environment or applications SHALL be made compatible with the design parameters for all snubbers in this FMG.

No additional testing is required provided the above corrective actions have been taken.

B. Maintenance, Repair, or Installation; and Application-Induced Failure Mode. When the corrective actions of 5.3.12A.1 are not applicable, or are not taken, the following applies:

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 23 of 26

1. Tests in the FMG SHALL be based both on the number of unacceptable snubbers found in the DTPG and determined by the failure evaluation to be appropriate for establishing the FMG, and on the number of unacceptable snubbers subsequently found in the FMG.

2. Testing SHALL continue until the mathematical formula ISTD-5331 is satisfied or all the snubbers in the FMG have been tested.

C. Transient Dynamic Event: Although additional samples of this FMG are not required, the operational readiness of all snubbers in this FMG SHALL be evaluated by stroking or testing. All operationally ready snubbers in this FMG SHALL be eligible for selection and testing for other appropriate FMGs and the DTPG.

5.3.13 In addition to the evaluation of the snubber, an evaluation SHALL be performed on the system(s) or component of which an unacceptable snubber is a part to determine if the supported system(s) or component may have become damaged or overstressed. This evaluation will be performed by the CAP process.

5.3.14 Selection of snubbers for expanded exams- When a snubber failure of a safety related snubber occurs, an additional sample must be identified and functionally tested. This sample SHALL represent 5% of the original DTPG. Selection of snubbers for expanded exams will be made based upon their operating conditions. The snubber selections will be based upon the following considerations (as applicable).

A. Snubbers of the same manufacturer's design, B. Snubbers immediately adjacent to those found unacceptable, C. Snubbers from the same piping system, D. Snubbers from other piping systems that have similar operating conditions, such as temperature, humidity, vibration, and radiation, E. Snubbers that are previously untested.

5.3.15 Causes for any test failure SHALL be determined and considered in establishing or reestablishing service life.

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 24 of26 5.4 Repair/Replacement of Snubbers Installed on ASME Code Class Components 5.4.1 Snubbers that are installed on ASME code class components are also considered code class components. Replacing a code class snubber is an ASME XI Repair/Replacement Activity. When code class snubbers are rotated from stock under ASME Section XI, 2007 Edition through 2008 Addenda, Article IWA-4132, and meet the conditions listed below, a repair/replacement plan and NIS-2 form are not needed.

A. Items being removed and installed SHALL be of the same design and construction.

B. Items being removed SHALL have no evidence of failure at the time of removal.

C. Items being rotated SHALL be removed and installed only by mechanical means.

D. Items being installed SHALL previously have been in service.

E. The owner SHALL track the items to ensure traceability of inservice inspection and testing records.

F. Use of an Inspector and an NIS-2 form are not required.

G. Repair/Replacement activities on removed items shall be performed in accordance with the requirements of this Article.

A Repair/Replacement Plan and Form NIS-2 are required for a snubber rotated from stock that does not meet the above requirements.

5.4.2 If any load transmitting parts of a snubber are replaced during a snubber overhaul (i.e., anything but seals and gaskets), the repair is considered an ASME Repair/Replacement Activity and a Repair/Replacement Plan and Form NIS-2 are required. All snubbers, regardless of previous installed location, are treated this way since the repaired snubber may be installed in an ASME Code Class location in the future.

All Repair/Replacement Activities on snubbers SHALL be followed up with a snubber functional test to ensure the quality of the repair.

5.4.3 All snubbers SHALL be serialized and tracked as to installed location for the life of the snubber.

5.5 Records

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 25 of 26 5.5.1 Preservice Inspection Records A. Records of the preservice inspection program SHALL be included in the work order and SHALL include preservice functional test results.

B. Preservice examinations of replacement snubbers SHALL be documented on 045.4, "Snubber Removal and Installation Procedure".

5.5.2 lnservice Inspection Records A. Records of the inservice inspection program SHALL be included in the work order and SHALL include inservice visual and functional test results.

B. lnservice examinations of replacement snubbers SHALL be documented on 045.4, "Snubber Removal and Installation Procedure".

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 26 of 26 Table 1 Snubber Visual Examination Interval Number of Unacceptable Snubbers Population Column A Column B Column C or Category Extend Interval Repeat Interval Reduce Interval (Note 1) (Notes 2 and 3) (Notes 2 1 4 1 5) (Notes 2 1 5 1 6) 1 0 0 1 80 0 0 2 100 0 1 4 150 0 3 8 200 2 5 13 300 5 12 25 400 8 18 36 500 12 24 48 750 20 40 78 1000 or greater 29 56 109 Note 1: Interpolation between population or category sizes and the number of unacceptable snubbers is permissible. The next lower integer SHALL be used when interpolation results in a fraction.

Note 2: The basic interval SHALL be the normal fuel cycle up to 24 months. The examination interval may be as great as twice, the same, or as small as fractions of the previous interval as required by the following Notes. The examination interval may vary +/-25% of the current interval.

Note 3: If the number of unacceptable snubbers is equal to or less than the number in Column A, then the next examination interval may be increased to twice the previous examination interval, not to exceed 48 months. In that case, the next examination according to the previous interval may be skipped.

Note 4: If the number of unacceptable snubbers exceeds the number in Column A, but is equal to or less than the number in Column B, then the next visual examination SHALL be conducted at the same interval as the previous interval.

Note 5: If the number of unacceptable snubbers exceeds the number in Column B, but is equal to or less than the number in Column C, then the next examination interval SHALL be decreased to two-thirds of the previous examination interval or, in accordance with the interpolation between Columns B and C, in proportion to the exact number of unacceptable snubbers.

Note 6: If the number of unacceptable snubbers exceeds the number in Column C, then the next examination interval SHALL be decreased to two-thirds of the previous interval.

Xcel Energy DEC 18 2014 L-PI-14-131 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 Fifth Ten-Year Interval Snubbers Testing Program Pursuant to the guidance of the American Society of Mechanical Engineers (ASME) OM Code, 2004 Edition, Code for Operation and Maintenance of Nuclear Power Plants, Section ISTA-3200(a), Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits for NRC information the fifth ten-year interval for the Prairie Island Nuclear Generating Plant (PINGP),

Units 1 and 2, snubbers testing program. The PINGP fifth ten-year interval begins December 21, 2014.

The fifth ten-year interval snubbers program is Enclosure 1 to this letter. The program was developed to satisfy the snubbers preservice and inservice testing and examination requirements of the ASME OM Code 2004 Edition through 2006 Addenda.

If there are any questions or if additional information is needed, please contact Mr. Ben Hammargren at 651-267-6830.

1717 Wakonade Drive East

Welch, Minnesota 55089-9642 Telephone: 651.388.1121

Document Control Desk Page 2 Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.

J~~C>>._c Kevin Davison Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosures (1) cc: Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC

ENCLOSURE 1 Prairie Island Nuclear Generating Plant Snubber Examination and Functional Test Program H20, Revision 10 26 pages follow

PRAIRIE ISLAND NUCLEAR GENERATING PLANT H PROCEDURE NUMBER:

SNUBBER EXAMINATION AND H20 H FUNCTIONAL TEST PROGRAM REV: 10 Page 1 of 26 INFORMATION USE

Procedure may be performed from memory.

User remains responsible for procedure adherence.

Procedure should be available, but not necessarily at the work location.