ML20084U920
ML20084U920 | |
Person / Time | |
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Site: | Ginna ![]() |
Issue date: | 01/31/1991 |
From: | Ransom C IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY |
To: | NRC |
Shared Package | |
ML20084U914 | List: |
References | |
CON-FIN-A-6812 EGG-NTA-8975, TAC-73380, NUDOCS 9104230479 | |
Download: ML20084U920 (75) | |
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Attachment 2 EGG NTA-4975 4 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM ROBERT E. GINNA NUCLEAR POWER PLANT Docket No. 50 244 C.-B. Ransom Published January 1991 i 6 Idaho National Engineering Laboratory- -
EG&G Idaho, Inc.
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J. Prepared for the U.S. Nuclear Regulatory Comission Washington, D.C. 20555 Under DOE Contract No. DE-AC07 761001570 FIN No. A6812 TAC No. 73380 9104230479 910131" PDR ADOCK 05000244 P PDR
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CONTENTS A8STRACT .............................................................. 111 PREFACE ................................................................ iii
- 1. INTRODUCTION ....................................................... 1
- 2. PUMP TESTING PROGRAM ............................................... 3 2.1 All Pumps in the IST Program ................................. 3 2.1.1 Pump 8 earing Temperature Measurements ................. 3 2.1.2- Full Scale Range of Vibration Instruments ............. 4 2.2 _ Diesel Generator' Fuel Oil Trans fer Pumps . . . . . . . . . . . . . . . . . . . . . 6 2.2.1 Pump Flow Rate Measurements ........................ .. -6 2.3 Containment Spray and Safety injection Pumps .................r 7
.2.3.1 Pump Inlet Pressure Measurements ...................... 7 2,4 Service Water-Pumps .......................................... 8 2.4.1 Pump Inlet Pre s sure Me asurements . . . . . . . . . . . . . . . . . . . . . . 8-2.4.2 Pump Vibration Measurements ........................... 10 o 2.4.3 Pump Flow Rate Measurements ........................... 11
- 2. 5 Re sidual Heat Removal Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 i
2.5.1 Establishing Reference Pump Flow Rate or -
Differential Pressure ................................. 12
- 3. VALVE TESTING PROGRAM .............................................. 15 3.1 General Valve Relief Requests ...'............................. 15 3.1.1 Part-Stroke Exercising Power Operated Valves .......... 15 i
1 3.1.2 Leak Rate Testing Containment Isolation Valves . ... . . . . 16 3.1.3 Verifying Reverse Flow Closure of Containment ,
Isolation Check Valves ................................ 17 3.1.4 Measuring Stroke Times of Rapid Acting Power O p e r a t ed V al v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1.5 Leak Rate -Testing RCS Pressure Isolation Valves ....... 19 3.1.6- Measuring Stroke Times of Hand Control Valves ......... 21 3.1.7 Trending Stroke Times for Power Operated Valves ....... 22 3.2 Emergency Diesel Generator Air Start System .................. 23 3.2.1 C a t e g o ry B V al v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.2.2 Category C Valves ..................................... 25 y
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3.3- Residual Heat Removal System ................................. 27 3.3.1 Category A/C Valves ................................... 27 3.3.2 Category C Valves ..................................... 29 3.4 Auxiliary Feedwater System ................................... 31 3.4.1 Category B Valves ..................................... 31 3.4.2 Category C Valves ..................................... 33 3.5 Station Service Water System ................................. 37 3.5.1 Category B Valves ..................................... 37 3.5.2 Category C Valves ..................................... 39 3.6 Reactor Coolant Pressurizer .................................. 41 3.6.1 Category C Valves:..................................... 41 3.7 Safety Injection System ...................................... 42 3.7.1 Category A/C Valves ................................... 42 3.7.2 Category C Valves ..................................... 49
~3.8 Containment Spray System ..................................... 51 3.8.1 Category A/C Valves ................................... 51 3.9 Chemical and Volume Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.9.1 C a t e g o ry B/ C V a l v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.10 Instrument Air System-....................................... 54 3.10.1 _ Category A Valves .................................... 54 3.11 Overpressure Protection Nitrogen Supply System .............. 55 3.11.! ' Category A/C Valves .................................. 55 3.11.2- Category B Valves .................................... 57 3.12 Emergency Diesel Generator Fuel Oil Transfer System ......... 58 L
l 3.12.1 Category B Valves .................................... 58
- 3.12.2 Category C Valves .................................... 60 3.13 Main Feedwater System ....................................... 62
- l. 3.13.1 Category C Valves .................................... 62 L
L APPEN0lX A--IST PROGRAM ANOMAL.lES IDENTIFIED DURING THE REVIEW ........ A-1 l
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11.- w, ABSTRACT This EG&G Idaho, Inc., report presents :the results of our evaluation of the Robert E. Ginna-Nuclear Power Plant inservice Testing Program for pumps and valves whose function is safety related, PREFACE Thisl report is supplied as part of the " Review of Pump and Valve Inservice Testing Programs for Operating Reactors (111)"-being conducted for the U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation,-Mechanical Engineering Branch, by EG&G Idaho, Inc., Regulatory and Technical Assistance Unit.
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1 FIN No. A6812 B&R 920-19-05-02 0 Docket No. 50-244
-TAC No. 733E0
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t TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM ROBERT E. GINNA NUCLEAR POWER PLANT
- 1. INTRODUCTION Contained herein is a technical evaluation of the pump and valve inservice testing (IST) program submitted by the Rochester Gas and Electric Corporation for its-Robert E. Ginna Nuclear Power Plant.
A working session with Rochester Gas and Electric Corporation and Robert E. Ginna Nuclear Power Plant representatives was conducted on November 1-and 2, 1988. The licensee's IST program for the interval from January.1, 1990, through December 31, 1999, (third 120 month inspection interval). transmitted by letter dated May 23, 1989, as amended by their submittals dated October 27, 1989,- February 15, 1990, and March 14, 1990, was reviewed to_ verify compliance of proposed tests of pumps-and. valves whose function is safety related with the requirements of the ASME Boiler and Pressure. Vessel Code (the Code),Section XI, 1986 Edition. Any IST program revisions subsequent to those noted above are not addressed-in this technical evaluation report (TER). Program changes involving additional or revised relief requests should be submitted to the NRC under separate cover in order to receive prompt attention, but should not be implemented prior to review and approval by the NRC. Other IST program revisions should follow the
! guidance in Section D of Generic letter No. 89-04, " Guidance on Developing Acceptable-Inservice Testing Programs."
In its IST program, Rochester Gas and Electric Corporation has requested relief from the ASME Code testing requirements for specific pumps and' valves and these requests have been evaluated individually to determine if the criteria in 10 CFR- ' 55a for granting relief are indeed met for the specified pumps or v,1ves. This review was performed utilizing the acceptance criteria of the Standard Review Plan, Section 3.9.6, the Draft Regulatory Guide and Value/ Impact Statement titled, " Identification of Valves for Inclusion in Inservice Testing Programs," and Generic Letter No. 89 04,
" Guidance on Developing Acceptable Inservice Testing Programs." IST program 1
. e testing requirements apply only to component testing (i.e., pumps and valves) and are not intended to provide the basis to change the licensee's current Technical Specifications for system test requirements, Section 2 of this report presents the Rochester Gas and Electri:
Corporation bases for requesting relief from the Section XI requirements for the Robert E Ginna Nuclear Power Plant pump testing program and the reviewer's evaluations and conclusions regarding these requests. Similar information is presented in Section 3 for the valve testing program, Justifications for exercising Category A, B, and C valves during cold shutdowns and refueling outages instead of quarterly during power operations were reviewed and found acceptable except as noted in Appendix A.
Inconsistencies and omissions in the licensee's IST program noted during the course of this review are listed in Appendix A. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
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- 2. PUMP TESTING PROGRAM The Robert E. Ginna Nuclear Power Plant IST program submitted by Rochester Gas and Electric Corporation was examined to verify that all pumps that are included in the program are subjected to the periodic tests required by the ASME Code,Section XI, except where specific relief from testing has been requested as identified below. Each Rochester Gas and Electric Corporation basis for requesting relief from the pump testing requirements and the reviewer's evaluation of that request are summarized below.
2.1 All Pumos in the IST Prcaram 2.1.1 Pumo Bearino Temoerature Measurements 2.1.1.1 Relief Recuest. The licensee has requested relief from the bearing temperature measurement requirements of Section XI, Paragraph IWP 3100, for all pumps listed in their IST program and proposed to use quarterly pump vibration measurements to determine pump mechanical condition and detect mechanical degradation.
2.1.1.1.1 Licensee's Basis for Recuestino Relief -Bearings of certain pumps addressed in this relief request are cooled by their respective process fluid. Thus, bearing temperature measurements would be highly dependent on the temperature of the cooling medium. Bearing temperatures taken at one-year intervals provide little data toward determining incremental degradation of a bearing or providing any meaningful trend information.
All pumps addressed by this relief request are subjected to vibration measurements on a quarterly basis in accordanc', with IWP-4500. Vibration measurements are a significant.ly more reliable indication of pump bearing degradation than are temperature measurements.
Alternate Testina: Pump mechanical condition of its bearings will be determined by quarterly vibration monitoring. Bearing temperatures will not be measured.
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2.1.1.1.2 Evaluation The licensee has indicated that a yearly measurement of pump bearing temperaturs for these pumps is not a meaningful test for detecting pump bearing degradation. There are several factors such as the working fluid temperature, ambient-temperature,' and lubricant temperature that would affect the measured bearing temperature and may mask any bearing condition change short of a catastrophic bearing failure. The quarterly pump vibration measurement gives a much more accurate indication of pump bearing condition than annual temperature measurements, and the vibration measurement is not substantially affected by any system parameter or other factor that could mask problems or result in erroneous indications of bearing degradation. A yearly bearing temperature measurement is impractical for these pumps because they do not have temperature sensors installed in the bearings and many are inaccessible for temperature measurements such as the deep draft pumps which are submerged in the working
-fluid. The burden on the. licensee if the Code requirements were imposed would not be justified by-the limited'information that would be provided about pump bearing condition.
Based on-thelimpracticality of complying with-the Code requirement of taking pump bearing temperature measurements and the level of quality and safety provided by-the-proposed quarterly pump vibration measurements that
- will be taken-to determine pump mechanical condition.and to detect pump-
-bearing degradation, relief _ may be granted from the Section XI requirement of annually measuring bearing: temperatures.
2.1.2 Full Scale Ranae of Vibration Instruments 2.1,2.1 Relief Reauest. The licensee has requested relief from the instrument full scale range requirements of Section XI, Paragraph IWP 4120, for all pumps listed in their IST program and proposed to use vibration detectors with multiple overlapping scales.
2.1.2.1.1 Licensee's Basis for Reauestina Relief--Vibration detectors usually have multiple overlapping scales rather than a single full range scale. It is not practical to apply the requirements of three times the reference value or less. When the reference value falls under 0.5 mils, 4
a detector in the three times or less scale would not allow a measurement in the required action range of 1.5 mils. (e.g., with a 0.3 mil reference value, using a detector with a range of 0.9 mils, determination of Alert Range" (1 1.5 mils) or " Required Action Range" (>l.5 mils) could not be accomplished.)
Alternate Testino: A vibration detector with multiple overlapping scales will be used. The amplitude of vibration for each test will determine which scale is to be used.
2.1.2.1.2 Evaluation The purpose of the full-scale range and accuracy requirements of IWP 4110 and -4120 is to ensure that pump test measurements are sufficiently accurate to permit evaluating pump condition and detecting degradation. ,The accuracy of multiple range instruments is generally based on the measured reading or on the full-scale range of the scale being usod and not on the total instrument range, therefore, the three times reference value or less requirement may not be appropriate to instruments with multiple overlapping scales. However, the multiple scale instrument must be at on a scale that produces an indication as close to mid scale as possible and provides an accuracy at least equivalent to the accuracy provided 0y a single range instrument that complies with both IWP 4110 and 4120.
Current vibration instruments usually have multiple ranges to cover a wide variation of vibration amplitudes. A single range instrument that complies with the full-scale range requirements of the Code could not practicably be used, since its range would not be adequate to measure both the reference value and the required action limit. The accuracy of multiple scale vibration instruments is mainly dependent on how accurately they are calibrated for the vibration frequencies being measured. Except for the vibration trequency extremes, these instruments are generally sufficiently accurate to allow determination of pump mechanical condition and permit the detection of mechanical degradation. Therefore, use of multiple range vibration instruments whose accuracy is equivalent to that provided by a single scale instrument that complies with the requirements of IWP-4110 and
-4120, should provide an acceptable level of quality and safety.
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Based on the determination that the proposed alternative of using multiple range vibration instruments should provide equivalent vibration data as would be provided by instrumentation that meets the Code range requirements, relief may be granted provided that the accuracy of the vibration instruments, on the scales used for the vibration measurements, is equivalent to that provided by a single scale instrument that complies with the requirements of IWP 4110 and 4120, 2.2 Diesel Generator Fuel Oil Transfer Pumos 2.2.1 Pumo Flow Rate Measurements 2.2.1.1 Relief Reouest. The licensee has requested relief from the flow rate measurement requirements of Section XI, Paragraph IWP 4600, for the .
diesel generator fuel oil transfer pumps (PDG02A and B) and proposed to determine pump flow rate by measuring the change in day tank level versus time.
2.2.1.1.1 Licensee's Basis for Reouestina Relief Measurement of diesel fuel oil transfer pump flow rate is determined by observing the rate of change in the diesel generator day tanks as they are being filled. A graduated sight glass located on the day tank is the only practical means available to calculate flow rates.
Alternate Testino: Flow rate will be determined by calculation of day tank level increase vs. time.
2.2.1.1.2 Evaluation -lWP 3100 requires the quarterly measurement of. pump-test-quantities including pump flow rate. There are no installed instruments on the diesel fuel oil transfer system that allow a direct measurement of the flow rate when testing these pumps. The pump flow rate can be calculated by measuring the change in day tank level or volume and the pump operation time required to make that change. This method yields a value for pump flow rate that can be used to evaluate pump hydraulic condition and detect degradation provided that it is repeatable and meets the accuracy i requirements of Table IWP-4110-1.
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Calculated pump flow rates that are sufficiently accurate and repeatable can be used in conjunction with pump differential pressure measurements to monitor pump hydraulic condition and degradation and should provide reasonable assurance of pump operational readiness. Requiring the licensee to install flow rate instrumentation would be costly and result in hardship without a compensating increase in the level of quality and safety.
Based on the determination that requiring the licensee to install flow rate instrumentation would result in hardship without a compensating increase in the level of quality and safety and considering the adequacy of the licensee's proposed alternate testing, relief may be granted from the Code requirement provided that the licensee obtains sufficiently accurate and repeatable data to comply with the Allowable Ranges and Corrective Action requirements specified in IWP 3200.
2.3 Containment Sorav and Safety Iniection Pumos 2.3.1 Pumo Inlet Pressure Measurements 2.3.1.1 Relief Reauest. The licensee has requested relief from the inlet pressure measurement requirements of Section XI, Paragraph IWP-3100, for the containment spray (CS) (SIAPCS 1 and 2) and safety injection (SI)
(SIAPSI 1 and 2) pumps and proposed to determine pump inlet pressure by
-measuring the refueling water storage tank (RWST) level.
2.3.1.1.1 Licensee's Basis for Reauestino Relief--Due to system design, the 51 and CS pumps do not have installed local or remote inlet pressure reading devices. The pumps are aligned to the RWST during testing and calibrated level indication is provided in the control room.
Alternate Testina: Pump suction pressure for these systems will be calculated utilizing RWST levels.
2.3.1.1.2 Evaluation -These pumps take a suction from the RWST and their inlet pressure is due to the head of water above the level of the pump inlet. The inlet pressure for an idle pump can easily be determined by 7
1 measuring the RWST level and performing a simple calculation, it is impractical to determine the inlet pressure when the pump is operating because there are no installed inlet pressure instruments. However, significant blockage of the pump suction during testing would be indicated by a reduction in the pump flow rate. The licensee can calculate pump inlet pressure by measuring the water level above the pump suction and subtracting it from the measured discharge pressure to determine pump differential pressure. Using the calculated pump differential pressure in conjunction with the pump flow rate should provide adequate information to ascertain the hydraulic condition of the pump and to detect any pump hydraulic degradation.
System modifications would be necessary to allow direct measurement of pump inlet pressure and the additional information provided would have a minimal impact on the licensee's ability to detect pump hydraulic degradation. Requiring the licensee to perform these modifications would be burdensome due to the high cost involved.
Based on the determination that measuring pump inlet pressure when the pump is operating is impractical, that it would be a burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
2.4 Service Water Pumos 2.4.1 Pumo Inlet Pressure Measurements 2.4.1.1 Relief Reauest. The licensee has requested relief from the inlet pressure measurement requirements of Section XI, Paragraph IWP-3100, for the service water pumps (PSWO 1A, IB, 10, and 10) and proposed to determine pump inlet pressure by measuring the lake water level above the pump inlet.
2.4.1.1.1 Licensee's Basis for Reauestina Relief -Service water pumps are submerged multistage vertical pumps and inlet pressure is assumed to correspond to that of the static head of the medium in which the pumps I
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reside (lake). Since the lake level remains essentially constant throughout the duration of the test, only one measurement is required.
Alternate Testino: For the Service Water pumps a single suction pressure l will be calculated for each test based on submergence of the pump.
2.4.1,1,2 Evaluation- The service water pumps are vertical deep draft pumps that are submerged in and take suction from Lake Ontario, therefore, their inlet pressure is due to the head of water above the level of the pump inlet. The inlet pressure for an idle pump can easily be determined by measuring the lake level and performing a simple calculation.
it is impractical to determine the inlet pressure when the pump is operating because there are no installed inlet pressure instruments. However, significant blockage of the pump section during testing would be indicated by a reduction in the pump flow rate. The lictnsee can calculate pump inlet pressure by measuring the water level above the pump suction and subtracting it from the measured discharge pressure to determine pump differential pressure. Using the calculated pump differential pressure in conjunction with the pump flow rate should provide adequate information to ascertain the hydraulic condition of the pump and to detect any pump hydraulic degradation.
System modifications would be necessary to allow direct moasurement cf pump inlet pressura and the additional information provided would have a minimal impact on the licensee's ability to detect pump hydraulic degradation. Requiring the licensee to perform these modifications would be burdensome due to-the high cost involved.
Based on the determination that measuring pump inlet pressure when the pump is operating is impractical,--that it would be a burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
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2.4.2 pumo Vibration Measurementt 2.4.2.1 Relief Recuest. The licensee has requested relief from the vibration measuremant requirements of Section XI, Paragraph IWP 4510, for the service water pumps (PSWO 1A, IB, 1C, and 10) and proposed to measure vibration on the associated pump motor bearing housing.
2.4,2.1.1 Licensee's Basis for Reouestina Relief The Service Water pumps are vertical, multistage pumps submerged in their process fluid and thus are inaccessible. Therefore, vibration measurement is impractical.
Alternate Testina: Vibration measurements will be taken on the pumps' associated motor bearing housing for indication of pump bearing degradation.
2.4.2.1.2 Ly.tluation. lWP 4510 requires that the vibration measurements be made on the pump bearing housing or its struc,tural support, provided it is not separated from the pump by any resilient mounting, complying with the Code requirements is impractical because the service water pumps are vertical deep draft pumps that are submerged in water and inaccessible for vibration measurements. Major system modifications would be necessary, such as replactrg these pumps with ones that are not submerged, to permit meeting the Code requirements. Requiring the licensee to make these modifications would be burdensome due the high costs involved, industry exptrience has shown that vibration measurements made on the pump driver housing near the thrust bearing can provide adequate information about pump condition. Therefore, vibration measurements taken on the motor bearing housing of these pumps should provide a reasonable indication of pump mechanical condition and permit the detection of degradatior.. The licensee's proposed testing should_ provide an acceptable citernative to the Code requirements.
Based on the impracticality of taking the service water pump vibration measurements on the pump housing and the determination that vibration measurements taken on the motor bearing housing provide informe.tton to evaluate pump mechanical condition and to detect bearing degradation, relief may be granted from the Code re.quirements as requested.
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9 2.4.3 Pumo Flow Rate Measurements g
2.4,3.1 Relief Reauest, The licensee has requested relief from the flow rate measurement requirements of Section XI, Paragraph IWP 4600, for the service water pumps (PSWO 1A, IB, IC, and 10) and proposed to measure the flow rate in the containment fan cooler outlet lines, i
2.4.3.1.1 Licensee's Basis for.Reauestina Relief..The present system configuration and instrument does not provide flow indication at the SW pump discharge lines to provide a positive means of detemining full flow-during pump tests.
Alternate Testina SW pump flow testing will utilize calibrated flow instrumentation installed ~
in the Containment Fan Cooler outlet lines.
Accident flow rates are utilized to assess p op performance.
2.4.3.1.2 Evaluation !WP 3100 re< uires the quarterly measurement of pump test quantities including pump flow rate. There are no installed instruments on the service water headers that permit measurement of. full pump flow rate during quarterly testing. The current system configuration makes it-impractical to install permanent flow rate instrumentation or use portable flow instruments that meet the Code accuracy requirements which can measure ,
total pump flow rates. The licensee has proposed to use the calibrated flow l rate instruments in the cooling lines at the outlet of the containment fan coolers for testing. Using a branch line flow measurement opens up the i
possibility.of test flow being affected by variations in control l valve settings in the various parallel flow paths. These variations could mask pump degradation and permit a degraded pump to remain in operation unless caution is taken to ensure repeatable test conditions are always established. If repeatable conditions are established for each test, use of these instruments should provide _ measurements which can be evaluated with other IST data to detemine pump hydraulic condition and detect degradation.
The licensee's proposed testing should give reasonable assurance of pump operational readiness provided they ensure that repeatable conditions are established during testing..
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System modifications would be necessary to allow measurement of full pump flow rate and the additional information obtained would have a minimal impact on the licensee's ability to detect pump hydraulic degradation.
Requiring the licensee to perform these modifications would be burdensome due to the high cost involved.
Based nn the determination that it is impractical to measure total pump flow rate during testing, that it would be a burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements provided the licensee establishes repeatable test conditions which permit obtaining data that is meaningful for detecting pump degradation.
2.5 Residual Heat Removal Pumos 2.5.1 Establishino Reference Pumo flow Rate or_ Differential Pressure 2.5.1.1 Relief Recuest. The licensee has requested relief from the Section XI, Paragraph IWP 3100, requirement to vary system resistance until the flow rate or differential pressure equals its reference value, for the residual heat removal (RHR) pumps (ACAPRH 1 and 2) and proposed to measure pump flow rate, differential pressure, and vibration quarterly while running in the recirculation flow path and test these pumps during cold shutdowns and refueling outages with the pumps operating at a substantial flow rate.
2.5.1.1.1 Licensee's Basis for Reouestino Relief Ouring power operation RHR pumps can only be tested utilizing minimum flow return lines.
These lines have flow orifices installed and do not allow throttling to an established reference value for either flow or pressure.
Alternate Testino: These pumps shall be tested quarterly measuring observed flow, differential pressure and vibration. The pumps shall be tested using the normal flow path during cold shutdowns and refueling outages. Data from both test frequencies shall be trended as required by IWP 6000. (re, Generic Letter 89 04, Attachment 1, Position 9) 12
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2.5.1.1.2 Evaluation lWP 3100 requires varying system resistance until pump flow rate or differential pressure is at its respective reference value. The RHR pumps do not develop sufficient head to pump into the RCS ,
during power operations, therefore, they can only be tested by pumping l through a minimum flow path. The minimum flow path resistance is fixed and )
cannot be varied to establish reference flow rate or differential pressure, therefore, it is imprt.ctical to comply with this Code requirement. A system j modification would be necessary to permit varying system resistance in the '
minimum flow recirculation line. It would be burdensome to require the licensee to perform this modification since it would be costly.
The licensee has proposed to perform an as found test quarterly with the pump operating in the minimum flow loop. During this testing pump flow rate, differential pressure, and vibration will be measured. The pump test data will also be measured during cold shutdowns and refueling outages with the pump operating in the normal flow path at a substantial flow rate. This testing is in accordance with Generic l.etter 89 04, Attachment 1, Position 9, and should provide reasonable assurance of pump operational readiness.
Based on the determination that it is impractical to establish reference pump flow rate or differential pressure during quarterly testing, that it would be burdensome to require the licensee to comply with this Code requirement, and considering the adequacy of the licensee's proposed alternative testing, relief may be granted from the Code requirement as requested, i
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- 3. val.VE TESTING PROGRAM The Robert E. Ginna Nuclear Power Plant IST program submitted by Rochester Gas and Eltetric Corporation was examined to verify that all valves included in the program are subjected to the periodic tests required by the ASME Code,Section XI, and the NRC positions and guidelines. The reviewer found that, except as noted in Appendix A or where specific relief from testing has been requested, these valves are tested to the Code requirements and established NRC positions. Each Rochester Gas and Electric Corporation basis for requesting relief from the valve testing requirements and the reviewer's evaluation of that request are summarized below and grouped according to system and valve category.
3.1 General Valve Relief Rgqqgiti 3.1.1 Part Stroke Exercisino Power Coerated Valves 3.1.1.1 Relief Reauest. The licensee has requested relief from the quarterly part stroke exercising requirements of Section XI, paragraph IWV 3412(a), for all power operated valves that are identified in the IST program and proposed to full-stroke exercise at cold shutdowns those valves which cannot practically be full stroke exercised quarterly during power operations. These valves will not be part stroke exercised quarterly.
3.1.1.1.1 Licensee's Basis for Reouestino Relief All motor operated and air operated valves in the Ginna IST Program have a design logic that prohibits part stroking of the valve. The circuits are such that when an open or close signal is received, the valve must complete a full stroke before the relay is released to allow the valve to stroke in the other direction. It is impractical to part stroke the valves.
Alternate Testino: Valves for which full stroke exercise is not practical during power operation, will be full stroke exercised during cold shutdown.
3.1.1.1.2 Evaluation- lWV-3412(a) states that if only limited operation of a power operated valve is practical during plant operation, 1
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the valve shall be part stroke exercised during plant operation and full stroke exercised during f.. ,hutdowns. The power operated valves at Ginna have control circuitry that does not permit a part stroke exercise of these valves. Once valve motion is initiated, it cannot be stopped until the valve completes a full stroke and the limit or torque switch is actuated to stop valve travel. Therefore, it is impractical to part stroke exercise power operated valves that cannot be full stroke exercised quarterly during power operations. System modifications would be necessary to permit these valves to be part stroke exercised. It would be burdensome to require the licensee to perform these modifications because it would be costly.
Full stroke exercising power operated valves during cold shutdowns that cannot practically be full stroke exercised quarterly during power operations should provide reasonable assurance of their operational readiness.
Based on the impracticality of part stroke exercising the applicable power operated valves, the burden on the licensee if this Code requirement were imposed, and considering the licensees proposal to full stroke exercise these valves during cold shutdowns and refueling outages, relief may be granted as requested.
3.1.2 Leak Rate Testino Containment Isolation Valves 3.1.2.1 Relief Reouest. The licensee has requested relief from the leak rate methodology and trending requirements of Section XI, Paragraphs
!WY 3421 through 3425 and IWV 3427(b), for all containment isolation valves identified in the IST program and proposed to leak rate test these valves in accordance to the requirements of 10CFR50, Appendix J, and the requirements I of Paragraphs IWV 3426 and 3427(a).
i 3.1.2.1.1 Licensee's Basis for Reauestino Relief it is NRCs staff position as outlined in Generic Letter No. 89 04, Position 10 that leak test l
procedures and requirements for containment isolation valves specified in 10CFR50, Appendix J are equivalent to requirements of IWV 3421 through 3425.
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Industry data shows that the variability of leak rates for valves six inches and larger is excessive. Ginna feels that this excessive variability shows the relative independence of one leak rate test to another. The
- tendency towards random leak rate data would cause unnecessary testing per
!WV 3427(b), with no identifiable increase in benefit to public health and safety.
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&ligrnate Testino: Containment isolation valves will be tested under the requirements of 10CFR$0, Appendix J. Leakage shall be analyzed as required by IWV 3426 and corrective action initiated in accordance with IWV 3427 (a).
3.1.2.1.2 Evaluation The NRC staff position on leak rate testing containment isolation valves is explained in Generic letter 89 04, Attachment 1, Position 10. The licensee's proposed testing is in accordance with this position and would provide an acceptable level of quality and safety.
Based on the determination that the proposed alternative would provide an acceptable level of quality and safety, relief may be granted as requested.
3.1.3 Verifyino Reverse Flow Closure of Containment isolation Check Valves 3.1.3.1 Relief Reauest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for valves 5393, 1713, and 7226, which are containment isolation check valves, and reoposed to verify the reverse flow closure of these valves in conjunction with Appendix J 1eak rate testing at least once every two years.
3.1.3.1.1 Licensee's Basis for Reouestino Relief When these valves are in operation there is no practical means to test valve closure.
. Valve closure cannot be verified due to system design.- To perform a closure verification constitutes a leak test which presents a significant hardship during cold shutdown, Leak testing requires an extended period of time where nitrogen, service air and instrument air must be secured.
4 17
Alternate Testino: Verification of valve closure will be done in conjunction withthe10CFR50AppendixJ.TypeC,leaktests(LT.J)conductedatleast once every two years.
3.1.3.1.2 Evaluation..These are simple check valves which are located at the primary containment boundary and are not equipped with position indication. The only method available to verify closure of these valves is to perform a leak test. Leak testing involves isolating the pneumatic supply, setting up test equipment and performing the actual test.
During this time, pneumatic pressure would be lost to the equipment located inside containment that is supplied by the affected system. Loss of pneumatic pressure could cause affected valves to reposition and other components to change state or cease to function. Many of these components are non safety related, however, their function may affect plant operation and isolating their pneumatic supply could result in a plant trip or require a plant shutdown. It is not practical to isolate a pneumstic supply to perform valve testing quarterly during power operation if doing so could result in a plant trip or shutdown.
It is impractical to leak test these check valves during cold shutdowns because it would require interruption of pneumatic pressure to equipment essential for plant operation in the shutdown mode. Further, establishing the requisite test conditions and conducting this testing during cold shutdowns could delay returning the plant to power which would be an undue burden on th 11censee, l
These valves receive an Appendix J, Type C, leak rate test during refueling outages. This testing should provide reasonable assurance of their capability of performing their safety function in the closed position.
l Based on the impracticality of complying with the Code requirements, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
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l 3.1.4 Measurina Stroke Times of Raoid Actina Power Ooerated Valves 3.1.4.1 Relief Recuest. The licensee has requested relief from the stroke time trending requirements of Section XI, Paragraph IWV 3417(a), for rapid acting power operated valves identified in the IST program and proposed to assign a limiting value of full stroke time of two seconds to these valves and perform corrective actions when the measured stroke time exceeds this two second limit.
3.1.4.1.1 Licensee's Basis for Reouestino Relief Since these valves are f ast acting and stroke rapidly, measurement of the stroke time of these valves to the nearest second per IWV 3413(b) means that a very small increase in stroke time results in an extremely large percentage of change.
Verification that test values meet a specified maximum stroke time of a relatively short duration provides adequate assurance of their operability.
Alternat3 Testina: A maximum stroke time of two (2) seconds will be assigned for these valves. If this limiting stroke time is exceeded, the valve will be declared inoperable and corrective action taken. (re, Generic Letter 89 04, Attachment 1 Position 6) 3.1.4.1.2 Evaluation The NRC staff position on evaluating stroke times of rapid acting valves is explained in Generic Letter 89 04, Attachment 1, Position 6. The licensee's proposed testing is in accordance with this position and would provide an acceptable level of quality and safety.
Based on the determination that the proposed alternative would provide an acceptable level of quality and safety, relief may be granted as requested.
3.1.5 Leak Rate Testina RCS Pressure Isolation Valves (PlVs) 3.1.5.1 Relief Reauest. The licensee has requested relief frt the leak rate testing requirements of Section XI, Paragraphs IWY 3421 through 3427, for the valves identified in the IST program as RCS pressure isolation 19
.i valves and proposed to leak rate test these valves in accordance with the plant Technical Specifications.
3.1.5.1.1 Licensee's Basis for Reauestina Relief. Leakage testing, l including testing requirements is governed by plant Technical Specifications. These valves are adequately tested per Technical Specifications. Testing criteria utilized meets the intent of ASME j Section XI leak rate testing. Therefore it is impractical to perform l separate leak rate tests.
Alternate Testina: These valves will be leak rate tested 'n accordance with RCS Pressure Isolation Valve leak rate testing per Technical Specifications.
3.1.5.1.2 Evaluation The Ginna plant Technical Specifications identify the valves that are leak rate tested as pressure isolation valves and establish the maximum permissible leakage rates, test pressure -
requirements, test frequency requirements, and required action if the leak rate limit is exceeded. The Technical Specification testing is not conservative in regards to the section XI Code requirements since in some cases the test method or frequency is less restrictive than the Code requirement. However, the licensee's testing has been reviewed and approved by the NRC in its review of the response to the Event V order and has-been determined to adequately verify the leak tight integrity of these valves. 'It would be burdensome to require the licensee to perform Section XI leakage rate testing of these valves in addition to Technical Specification leak-rate testing due to the time, cost, and personnel radiation exposures involved and-considering that it would not result in a compensating increase in the level of quality and safety.
l Based on the determination that compliance with the Code requirements would result in hardship without a commensurate increase in the level of quality and safety and considering the acceptability of the licensee's proposed ' alternate testing, relief may be granted from the Code requirements as requested.
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_ _ . ~ . _ . _ - _ . _ __ _
l 2
3.1.6 Measurino Stroke Times of Hand Control Valves 3.1.6.1 Relief Recuest. The licensee has requested relief from the i stroke time measurement requirements of Section XI, Paragraphs IW 3413 and 3417, for hand control valves which operate using a variable set air signal and proposed to verify valve operational readiness during quarterly exercising, but the stroke times will not be measured for these valves.
3.1.6.1.1 Licensee's Basis for Recuestino Relief. These valves are hand control valves which operate using a variable set air signal. They do not have a typical control switch, position indication is not directly indicated, only the control air signal is indicated. Therefore, there is no consistent way to measure the stroke time of these valves. Stroke time limiting values are not established by the UFSAR or Technical Specifications for these valves.
1 Alternate Testino: Operability of these hand control valves is verified during quarterly exercising tests. Measurement and evaluation of stroke time shall not be required for these valves.
3.1.6.1.2 Evaluati e These air operated valves are positioned by varying a control air signal using a manually adjustable controller. There 4 are no control switches that effect a full stroke open or closed of these valves. The only practical method of obtaining a continuous and repeatable '
full stroke exercise is to close the valves and then remove control air so the valves stroke to their open fail safe position.- These valves do not have remote position indication which makes it difficult to obtain stroke time measurements. Stroke timing provides a means of monitoring valve condition j l
and detecting degradation. However, the licensee's proposal provides no l means of detecting valve degradation unless it results in failure of the valve to change position. Some means should be developed to measure the full stroke time of these valves during quarterly fail safe testing. Since it would be burdensome to require the licensee to make system modifications that permit measurement of valve full stroke times immediately, an interim relief may be granted for the licensee to develop a method of evaluating the condition of these valves. The licensee's proposal of verifying valve 21 L
L I
f operational readiness during the quarterly exercising of the hand control valves should provide an acceptable level of quality and safety during the l
interim period.
Based on the impracticality of measuring valve full stroke times, the
- burden on the licensee if the Code requirements were immediately enforced, and considering the licensee's proposed alternate testing, interim relief may be granted for 12 months. During this interim period the licensee should develop an adequate means of monitoring for degradation of these valves.
3.1.7 Trendino Stroke Times for Power Ooerated Valves 3.1.7.1 Relief Reouest. The licensee has requested relief from the stroke time evaluation and corrective action requirements of Section XI, Paragraph IWV 3417(a), for all power operated valves that are identified in the IST program and proposed to follow a plan that is based on deviation from
- a reference stroke time instead of the previous test stroke time to identify valves for further evaluation and possibly increase their test frequency.
3,1.7.1.1 Licensee's Basis for Reouestina Relief The intent of the Code requirement is to initiate increased testing to verify a valve can continue to perform its intended function when it has degraded. Due to the variance in testing frequencies some valves may degrade over a period of time.
Measuring ch'anges in stroke time from the reference value (established when the valve is known to be in good condition) is a better indication of valve degradation.
Alternate Testin2: Changes in stroke time shall be measured from the reference value when determining increased test frequency requirements and initiationofcorrectiveactionperIWV3417(a). (re,Genericletter8904, Attachment 1 Position 5) 3.1.7.1.2 Evaluation The NRC staff position on basing stroke time corrective actions on deviations from reference values is explained in 1
22 l-.
- . - _ . - . - . - . - - - . - _ . - - -. . - - - . , . - - - . _ . - - . - _ . - = - . - - - . - - - . . - , , - . - - . - . ..
~ _.. --- _ _ __ _ _ _ _ _.__ _ _ _ _.__ _ _.___ _ _ _ _
i .
+
1 Generic Letter 89 04, Attachment 1, Positions 5 and 6. The Section XI j requirement to compare measured stroke times to the previous values can
- permit a stair stepping gradual increase in valve stroke times to occur j without taking corrective action or could require corrective action due to ,
3 normal data scatter for a valve that is functioning properly. Basing corrective action on deviation from a reference stroke time determined when the valve is known to be in good condition would not permit a gradual increase in stroke times to continue without taking the appropriate corrective action nor would unwarranted increased testing be required due solely to normal data scatter. Increasing the valve test frequency to monthly when the measured stroke time is greater than 50% above the reference value for valves with stroke times of 10 seconds or less and when the measured stroke time is greater than 25% above the reference value for valves with stroke times greater than 10 seconds would provide equivalent or better protection than provided_by the Section XI corrective action requirements.
Comparing measured stroke times to reference values as explained above would e provide an acceptable level of quality and safety.
Based on the determination that the proposed alternative would provide an acceptable level of quality and safety, relief may be granted to compare measured stroke times to reference values provided that implementation of the monthly test frequency is determined as discussed above.
3.2 Emeroency Diesel Generatg.r Air Start System 3.2.1 Cateaory B Valves 3.2.1.1 Relief Reauest. The licensee has requested relief from the stroke time measurement requirements of Section XI, Paragraphs IWV 3413 and 3417, for the emergency diesel generator air start solenoid operated valves, 5933A, 59338, 5934A, and 59348, and proposed to demonstrate operational i
readiness of these valves by observing that the diesel monthly start' tests are acceptable, but the stroke times of these valves will not be measured.
I L 23 1
3.2.1.1.1 Licensee's Basis for Reouestino Relief These are rapid acting solenoid valves whose design prohibits visual observance of stroking as there are no external indicators on these valves. Diesel start times are affected by valve stroke times.
Alternate Testino: Heasurement and evaluation of stroke times shall not be performed. Valve exercising is performed monthly in conjunction with diesel generator start testing. Valve stroking parameters will be considered acceptable if the associated diesel generator start is acceptable. If the diesel generator failed to start, due to other identified malfunctions, repairs would be made and the air start valve stroking parameters will be verified during a restart following diesel generator corrective action.
3.2.1.1.2 Evaluation These valves are totally enclosed solenoid operated valves which have no externally visible indication of valve position, it is impractical to measure the stroke times of these valves because there is no way to determine when a valve receives a signal to open or when it reaches the open position. These valves are rapid acting valves which normally stroke almost instantly and when they do not operate promptly, they most comonly fail to operate at all.
These valves function to admit starting air to the diesel generator starting motors, therefore, it can be indirectly verified that each valve has opened by monitoring the diesel generator start times to insure that the diesel starts within the Technical Specification limit. Measuring the diesel start times gives an indication of possible valve degradation since any ,
significant change in valve stroke time would result in longer diesel generator start times. Valve full stroke times cannot be measured unless significant system modifications, such as replacing these diesel air start valves with valves that have valve disk position indication, are made to permit this testing. Replacing these valves to permit stroke time measurements would provide a limited amount of additional information above that generated by the proposed alternate testing, it would be burdensome for the licensee to make such modifications due to the high costs involved and a limited amount of additional information would be provided.
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Compliance with the Code requirements would be impractical. The f licensee's proposed alternate testing of measuring the diesel generator starting times should verify operation of the air start valves and monitor ;
their degradation. Therefore, considering the burden on the licensee if the !
Code requirements were imposed, relief may be granted from the Code requirements as requested.
3.2.2 Cateoory C '!alves 3.2.2.1 Relief Reouest. The licensee has requested relief from the exercising frequency and test method requirements of Section XI Paragraph IWV 3520, for the emergency diesel generator air start accumulator check valves. 5941A and 5942A, and proposed to verify the reverse flow closure capability of these valves by_ disassembly-and inspection on a sampling basis during refueling outages.
3.2.2.1.1 Licensee's Basis for Recuestino Relief During operation there is no practical means to exercise these valves. Valve closure cannot be verified due to system design. To perform-a closure verification would require a disassembly of mechanical joints in the piping, which would place the diesel in an inoperable condition.
Alternate Testing: One valve will-be disassembled, full stroke exercised and inspected each refueling outage on a rotating basis. If that valve fails, the remaining valve will be disassembled, full stroke exercised and-inspected during that same outage. (re, Generic Letter 89 04, Attachment 1 -
Position 2) 3.2.2.1.2 Evaluation These are simple check valves without remote or other external indication of disk position. The only non intrusive method of verifying valve closure is leak testing, such as performing an accumulator pressure decay test. It is impractical to leak test these valves quarterly during power operations because it requires disassembly of mechanical joints
'in piping which would result in the diesel generator being inoperable for extended periods of time. Performing this testing during cold shutdowns 25
could result in a delay in returning the plant to power, which would be burdensome to the licensee.
The licensee indicated that a further camplication to using an accumulator pressure decay test to verify valys e,losure is that the diesel l air start system contains a number of swage connections and other types of fittings that have significant leakage. This results in high system leakage rates which could prevent detection of a check valve that is not fully closing, j l
The Minutes of the public Meeting on Generic letter 89 04 state that the use of disassembly to verify closure capability may be found to be acceptable l depending on whether verification by flow or pressure measurements is i practical. The licensee has not adequate 1y shown the impracticality of verifying the reverse flow closure of the'se valves by leak testing during refueling outages, therefore, disassembly and inspection should not be employed on a long term basis in this situation. The Minutes of the Public Meeting on Generic Letter 89 04 also state that partial stroke exercise ,
testing with flow is expected to be performed after valve disassembly and
. inspection is completed but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the oisk moves freely.
Based on the determination that it is impractical to verify the reverse flow closure of these valves quarterly during power operation and during cold shutdowns, relief may be granted from the test-frequency requirements of the Code. .Considering that the licensee's proposal to disassemble and inspect these valves in accordance with Generic Letter 89 04, Attachment 1, -
Position 2, should provide reasonable assurance of valve operational readiness, interim relief may be granted from the Code test method requirements for one year or until the end of the next refueling outage, whichever is longer. During this interim period, the licensee should develop a method to verify the reverse flow closure capability of these valves other than disassembly and inspection.
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3.3 Residual Heat Removal System 3.3.1 Cateoory A/C Valves 3.3.1.1 Relief keouest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for the low head safety injection check valves, 853A and 8538, and proposed to part stroke exercise these valves during cold shutdowns and to full stroke exercise them during refueling cavity fill at refueling outages. The licensee also proposed to verify the closure of these valves by leak rate testing during refueling outages.
3.3.1.1.1 Licensee's Basis for Reouestino Relief Full or partial stroking during power operation is not possible because RHR pump discharge pressure is insufficient to overcome reactor coolant system (RCS) pressure.
Even if pump discharge pressures were high enough, any stroking could cause the injection of cold borated water into the system, resulting in power and thermal transients.
These valves cannot be full stroke exercised during cold shutdown because establishing required safety analysis flow through them could result in excessive RCS cooldown. ,
during power operation, there is no practical means to test valve closure. Valve closure cannot be verified due to system design. To perform a closure verification constitutes a leak test which presents significant hardships during cold shutdown, such as excessive radiation exposure to test personnel and extended outage time.
Alternate Testino: These valves will be partial stroke exercised at cold shutdown and full-stroke exercised at refueling during the refueling cavity fill. Verification of valve closure will be made in conjunction with ASME XI leak tests conducted during refueling outages.
3.3.1.1.2 Evaluation lWY 3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, 27
during cold shutdowns. The only path available to establish flow through these valves to full or part stroke exercise them is into the RCS. The residual heat removal pumps do not produce sufficient head to overcome RCS pressure during power operations, therefore, there are no sources capable of establishing flow through these valves quarterly during power o;;srations.
These valves cannot be full or part stroke exercised quarterly unless extensive system modifications, such as installing full flow test loops, are made which permit this testing. It would be burdensome for the licensee to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert the injection flow away from the RCS.
It is impractical to full stroke exercise these valves during cold shutdowns because establishing the required flow through them could result in excessive cooldown of the RCS. Excessive cooldown rates result in increased thermal stresses on RCS components which could lead to their premature failure.
These valves are simple check valves located inside containment with no position indication. The only practical method of verifying valve reverse flow closure is to perform a leak test. A containment entry would be required to leak test these valves and due to personnel hazards associated with a containment entry during power operations, it is impractical to perform this tuting quarterly. It is impractical to leak test these valves during cold shutdowns because it would subject test personnel to high radiation areas and, due to the involvement of setting up and removing test equipment, could delay startup from cold shutdowns.
The licensee proposed to part stroke exercise valves 853A and 853B during cold shutdowns, to full stroke exercise these valves during refueling outages and to verify their reverse flow closure during the Section XI leak rate test at refueling outages. This testing should give reasonable assurance of valve operational readiness and provide a reasonable alternative to the Code requirements.
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Based on the impracticality of full stroke exercising these valves quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
3.3.2 Cateaory C Valves 3.3.2.1 Relief Reauest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for the RHR pump discharge check valves, 697A, 6978, 710A, and 710B, and proposed to part stroke exercise these valves quarterly during power operations and full stroke exercise them during refueling outages.
3.3.2.1.1 Licensee's Basis for Reouestina Relief These valves cannot be full stroke exercised during power operation since downstream valves to the RCS cannot open against the higher RCS pressure. These valves cannot be full stroke exercised during cold shutdown because establishing required safety analysis flow thru them could result in excessive RCS cooldown.
Alternate Testina: These check valves are partial flow exercised at least quarterly during RHR system testing. Full stroke testing of these valves shall be performed during each refueling outage.
3.3.2.1.2 Evaluation lWV 3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, during cold shutdowns. The only path available to establish sufficient flow through these valves' to full stroke exercise them is into the RCS. The RHR pumps are the only source of flow through these valves and they do not produce sufficient head to overcome RCS pressure during power operations, therefore, it is. impractical to full stroke exercise these valves quarterly during power operations. Extensive system modifications, such as installing full flow test loops, would be necessary in order to full-stroke exercise these valves' quarterly, it would be burdensome for the licensee to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert the injection flow away from the RCS.
29
It is impractical to full stroke exercise these valves during cold shutdowns because establishing the required flow through them could result in excessive cooldown of the RCS. Excessive cooldown rates result in increased thermal stresses on RCS components which could lead to their premature failure.
The licensee proposed to part stroke exercise valves 697A, 6978, 710A, and 710B quarterly during RHR system testing and to full stroke exercise these valves during refueling outages. This testing should give reasonable assurance of valve operational readiness and provide a reasonable alternative to the Code requirements.
Based on the impracticality of full stroke exercising these valves quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, reitef may be granted from the Section XI requirements as requested.
3.3.2.2 Relief Reauest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for 854, the check valve in the RHR suction from the RWST, and proposed to full stroke exercise this valve during fill of the refueling cavity at refueling outages.
3.3.2.2.1 Licensee's Basis for Reauestino Relief Valve stroking is not possible daring power operation because RHR pump discharge pressure is insufficient to overcome RCS pressure. This valve cannot be full stroke exercised during power operation since downstream valves to the RCS cannot open against the higher RCS pressure.
This valve cannot be full stioke exercised during cold shutdown because establishing required safety analysis flow through it could result in excessive RCS cooldown.
Alternate Testina: Valve 854 will be full stroke exercised during the refueling cavity fill at refueling outages.
30
3.3.2.2.2 Evaluation lWV 3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, during cold shutdowns. The only path available to establish sufficient flow through this valve to full stroke exercise it is into the RCS. The RHR pumps are the only source of flow through this valve and they do not produce sufficient head to overcome RCS pressure during power operations, therefore, it is impractical to full stroke exercise valve 854 quarterly during power operations. Extensive system modifications, such as installing full flow test loops, would be necessary in order to full stroke exercise this valve quarterly, it would be burdensome for the licensee to make such modifications because of the cost involved.
It is impractical to full stroke exercise this valve during cold shutdowns because establishing the required flow through it could result in excessive cooldown of the RCS. Excessive cooldown rates result in increased thermal stresses on RCS components which could lead to their premature failure.
The licensee proposed to part stroke exercise valve 854 quarterly during RHR system testing and to full stroke exercise this valve during refueling outages. This testing should give reasonable assurance of valve operational readiness and provide a reasonable alternative to the Code requirements.
' Based on the impracticality of full stroke exercising this valve quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.-
3.4 Auxiliary feedwater Systems 3.4.1 Cateoory B Valves 3.4.1.1 Relief Reauest. The licensee has requested relief from the stroke time measurement requirements of Section XI, Paragraphs IWV 3413 and 3417, for the isolation valves in the auxiliary feedwater and standby auxiliary feedwater pump recirculation lines, 4291, 4304, 4310, 9710A, and 31
- w -
, ----+,,.,res W- er-- - + - -- t--- g pr +---- -- , - - r- w-
1 i
97108, and proposed to exercise these valves to verify their operational readiness, but valve stroke times will not be measured.
3.4.1.1.1 Licensee's Basis for Reauestino Relief These valves operate based upon a pressure / flow signal only. Manual activation of these valves is not practical in the present configuration. l.ifting of leads or jumpers, or installation of new instrumentation or controls would be necessary. Stroke timing during normal valve operation is affected by variations in system parameters, therefore measurement of stroke times for these valves would not produce consistent, meaningful or trendable results.
Alternate Testing: Measurement and evaluation of stroke times shall not be performed. These valves will be exercised and fail safe tested quarterly.
3.4.1.1.2 Evaluation These air operated valves are positioned in response to pressure / flow signals. They open to provide a path for recirculation flow to protect the auxiliary feedwater and standby auxiliary feedwater pumps from being damaged when they are running against shut off head or with restricted flow conditions and close when pump flow into the steam generators is sufficient to prevent pump damage. There are no control switches that effect a full stroke open or closed of these valves. Also, there is no remote valve position indication or other positive means to determine valve position. Without concise methods of initiating valve movement or to determine when the stroke is completed, it is extremely difficult to obtain repeatable stroke time data to monitor for valve degradation. Due to these limitations in obtaining repeatable stroke times, it is impractical to trend stroke times for these fast acting air operated valves.
In order to obtain trendable stroke times for these valves during normal valve operation it would be necessary to perform system modifications and/or to replace these valves with ones that have position indication. However, the licensee's proposal provides no means of detecting valve degradation.
Some means should be developed to monitor valve condition and detect degradation. Even if system modifications are not performed to permit the 32
I '
measurement of trendable stroke times, it may be possible for the licensee to develop a u thod of measuring stroke times and verifying that they remain under a reasonable maximum stroke time limit. Alternatively it may be possible to obtain trendable stroke time data during refueling outages with only limited extra measures. It would be burdensome to require the licensee to imediately develop a means of monitoring for valve degradation, therefore, an interim period should be provided for the licenses to develop a method of performing this testing. The licensee's proposal of verifying valve operational readiness by quarterly exercising and fail safe testing should provide an acceptable level of quality and safety during the interim i period.
Based on the impracticality of measuring and trending valve full stroke times, the burden on the licensee if the Code requirements are imposed, and considering the licensee's proposed alternate testing, interim relief may be granted for 12 months. During this interim period the licensee should develop an adequate means of monitoring for degradation of these valves.
3.4.2 Cateaery C Valves 3.4.2.1 Relief Reouest. The licensee requested relief from the exercising requirements of Section XI Paragrap'n IWV 3520, for the check valves in the service water line to the standby auxiliary feedwater pump suctions, 9627A and 9627B, and proposed to part stroke exercise these valves quarterly and to partially disassemble, inspect, and manually full stroke exercise them on a sampling basis during refueling outages.
3.4.2.1.1 Licensee's Basis for Reauestina Relief Full stroke exercising cannot be accomplished during power operation or cold shutdown as this could introduce Service Water to the Standby Auxiliary feedwater system. Service water does not meet water purity requirements for the system or steam generators. Service water would be supplied to steam generators during required monthly pump tests if exercising valves 9627A and B was performed.
33
l Alternate Testina: Partial stroke exercising will be performed each quarter. One valve will be disassembled, full stroke exercised and inspected each refueling outage on a rotating basis. If that valve fails, the remaining valve will be disassembled, full stroke exercised and inspected for operability during that same outage. (re. Generic letter 89 04, Position 2),
3.4.2.1.2 Evaluation Check valves 9627A and 9627B are in the service water line to the standby auxiliary feedwater pump suctions. The only path available to establish sufficient flow through these valves to full stroke exercise them is from the service water system into the standby auxiliary feedwater system. Service water comes directly from Lake Ontario and is relatively impure water which does not meet the water chemistry standards for the secondary system. Establishing full flow through these valves would contaminate the standby auxiliary feedwater system. After exercising these valves, an automatic initiation of the standby auxiliary feedwater system would result in low quality water being injected into the steam generators. Contaminating the steam generators with lake water could cause severe damage such as fouling heat transfer surfaces and increasing the itkelihood of stress corrosion induced tube failures. The process of draining and flushing the standby auxiliary feedwater system to restore water chemistry standards after exercising these valves is very complex, time consuming, and may not completely remove all contaminants, therefore, full stroke exercising these valves with service water flow at any time is impractical.
These valves cannot be full stroke exercised quarterly unless extensive system modifications, such as installing full flow test loops, are made which permit this testing. It would be burdensome for the licensee to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert service water flow away from the standby auxiliary feedwater system.
The licensee proposed to part stroke exercise these valves quarterly during power operations and to verify their full-stroke capability by partial disassembly, inspection, and manual exercise of the valve disk on a sampling basis during refueling outages. The Minutes of the Public Meeting on Generic b4
Letter 89 04 state that partial stroke exercise testing with flow is expected to be performed after valve disassembly and inspection is completed but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly ard that the disk moves freely.
Disassembly, together with inspection, to verify the full stroke capability of check valves is an option only where full stroke exercising cannot practically be performed by flow or by other positive mea.ns. The NRC staff considers valve disassembly and inspection to be a maintenance procedure that is not equivalent to the exercising produced by fluid flow.
This procedure has risks which may make its routine use as a substitute for testing inappropriate if some method of testing is possible. The licensee should actively pursue the use of non intrusive diagnostic techniques, such as acoustics, ultrasonics, or magnetics, to demonstrate that these valves open sufficiently during partial flow testing to permit meeting the valves' safety function.
Based on the impracticality of full stroke exercising these valves quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternative, relief may be granted from the Section XI requirements provided the licensee performs a partial flow test of the affected valve af ter valve disassembly and inspection is completed but before returning the valve to service. The licensee should actively pursue the use of non intrusive diagnostic techniques to demonstrate that these valves open sufficiently during partial flow testing to permit meeting their safety function. If another method is developed to verify the full stroke capability of these valves, this relief request should be revised or withdrawn.
3.4.2.2 Relief Reouest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IW 3520, for the check valve in the recirculation flow path of tu turbine driven auxiliary feedwater pump. 4023, and proposed to verify its full stroke capability by disassembly and inspection during each refueling outage, l
. 35
o .
3.4.2.2.1 Licensee's Basis-for Reauestino Relief. The present configuration provides no positive means to verify reverse closure capability.
Alternate Testino: Reverse flow closure capability of check valve 4023 shall be verified by disassembly inspection during each refueling outage. (re, Generic letter 89 04, Attachment 1 Position 2).
NOTE: In their letter dated March 14, 1990, RH E stated that valve 4023 does not perform a safety function in the closed position, therefore, they would delete the reverse flow closure of this valve from relief request VR 23. The relief request is still necessary because there are no flow rate instruments installed in this flow path to verify maximum required accident flow through the valve during testing. The licensee further indicated that instrumentation is to be installed during the 1990 refueling outage that will permit verifying a full stroke exercise of this valve during quarterly pump testing.
3.4.2.2.2 Evaluation This check valve is in the minimum flow recirculation line for the turbine driven auxiliary feedwater pump and receives substantial flow through it during the quarterly pump test.
Currently maximum required accident flow rate cannot be verified through this valve because there are no installed flow rate instruments. However, the licensee committed to install flow rate instrumentation in this line during the 1990 refueling outage.
The licensee proposed to part stroke exercise this valve quarterly
< during punp testing and to verify its full stroke capability by partial disassembly, inspection, and manus) exercise of the valve disk during refueling outages per the guidelines of Generic Letter 89 04, Attachment 1 Position 2. This proposal should provide reasonable assurance of valve ;
operational readiness and give an acceptable level of quality and safety provided the licensee performs a partial flow test of the valve after the disassembly and inspection procedure but before returning the valve to service.
Based on the impracticality of verifying a full stroke exercise of this valve quarterly or during cold shutdowns and considering the licensee's l
l 36
proposed alternative, interim relief may be granted from the Section XI requirements for a period of six months.
NOTE: The Itcensee indicated in a telephone conversation that an Annubar flow instrument that meets the Code accuracy and range requirements has been installed in this system. During that conversation, the licensee stated.that relief request VR 23 will be withdrawn following satisfactory testing of the instrument.
3.5 Station Service Water S.y.11gm 3.5.1 Cateoorv 8_Yalni 3.5.1.1 Relief Reauest. The licensee has requested relief from the stroke time measurement requirements of Section XI, Paragraph IWV 3413, for 4324, 4325, and 4326, the solenoid operated valves in the service water lines ,
to the auxiliary feedwater pump bearings, and proposed to exercise these valves quarterly to verify their operational readiness, but the stroke times will not be measured for these valves.
3.5.1.1.1 Licensee's Basis for Recocstina Relief This is a rapid acting valve. These valves automatically actuate on high differential pressure across the supply strainer. Measurement of stroke times during manual actuation, for testing, is not practical and would not produce .
consistent, meaningful or trendable results. Failure of the valve to stroke in conjunction with a clogged strainer would result in a lack of pressure at the bearing cooler inlet.
Alternate Testina: This valve will be stroke tested during associated auxiliary feedwater pump testing by closing the valve downstream of the strainer. Acceptable valve operation will be based on acceptable service water pressure at the bearing cooler inlet.
3.5.1.1.2 [yaluation These solenoid operated valves are positioned in response to differential pressure signals. They are normally closed and are required to open to provide a path of cooling flow to the auxiliary feedwater pump betrings to prevent pump damage when the supply strainer in the normal cooling path becomes clogged. There are no control 37
switches that effect a full stroke open or closed of these valves. Also, there is no remote valve position indication or other positive means to determine valvir position. Without concise methods of initiating valve movement or of determining when the stroke is completed, it is extremely difficult to obtain repeatable stroke time data to monitor for valve degradation. Due to these limitations in obtaining repeatable stroke times, it is impractical-to trend stroke times for these. fast acting valves.
In order to obtain trendable stroke times for these valves it would be i necessary to perform system modifications and/or to replace these valves with ones that have position indication. It would be burdensome to require the licensee to make the necessary system modifications since they could be costly. Also, these modifications could result in a decrease in system o reliability. However, the licensee's proposal provides no means of detecting valve degradation.
Some-meant should be developed to monitor valve condition and detect degradation. Even if system modifications are not performed to permit the measurement of trendable stroke times, it may be possible for the licensee to develop a method of measuring stroke times and verifying that they remain under a reasonable maximum stroke time limit. Alternatively it may be possible to obtain trendable stroke time data during refueling outages with only limited extra' measures. It would be burdensome to require the licensee to immediately develop a means of monitoring for valve degradation, therefore, an interim period should be provided for the licensee to develop a method of performing this testing. The licensee's proposal of verifying ;
valve operational readiness by quarterly exercising should provide an acceptable level. of quality and safety during the interim period.
Based on the impracticality of measuring and trending valve full stroke times, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, interim relief may be granted for 12 months. During this interim period the licensee should develop an adequate means of monitoring for degradation of these valves.
38
-- . . - . - . - _ ~ . - . - . -- .- - - . . - _ - - - - - -.-
3.$.3 Cateoory C Valves 3.0.01 Relief Recuest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWY 3520, for 4601, 4602, ,
4603,.and 4604, the service water pump discharge check valves, and proposed !
to part stroke exercise these valves open and verify their reverse flow closure quarterly during the service water pump testing and to verify their l full stroke capability by performing sample disassembly and inspection during refueling outages.
3.5.2.1.1 Licensee's Basis for Reouestino Relief The present system configuration and instru.nentation does not provide flow indication at the SW pump discharge lines to provide a positive means to verify full stroke open capability of taese check valves.
Alternate Testino: These check valves are exercised at least. quarterly during SW system testing during which required service water flow through each loop's containment fan cooler units is established and verified.
However, actual SW flow through each check valve is not measured during tnese tests. The capability of these valves to close upon cessation or reversal of flow is verified at least quarterly during the SW system tests.
The full-stroke open capability of these check valves shall be verified by disassembly inspection on a rotating sample basis each refueling outage.
If the sample valve fails, all remaining valves shall be disassembled and inspected for operability during that same outage. (re, Generic letter 89 04
- Position 2) 3.5.2.1.2 Evaluation--IWV-3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, during cold shutdowns. Valves 4601, 4602, 4603, and 4604 are the service water pump discharge checks which have' normal operating service water flow through them whenever the associated pump is in operation. Each service water pump is operated at a substantial flow rate at least quarterly, but there is no means of verifying that these check valves are fully open or that maximum required accident flow is established through them. There are no 39
flow rate instruments installed in the service water headers and the valves are simple check valves which have no position indication, in order to verify the full stroke capability of these valves using standard test methods it would be necessary to perferm extensive system modifications, such as installing flow rate instrumentation or valve position indication. It would be burdensome for the licensee to make such modifications because of the high costs involved.
The licensee proposed to part stroke exercise and verify the reverse flow closure of these valves quarterly during power operations and to verify their full stroke capability by partial disassembly, inspection, and manual exercise of the valve disk on a sampling basis during refueling outages. The Minutes of the Public Meeting on Generic letter 89 04 state that partial stroke exercise testing with flow is expected to be perfomed after valve disassembly and inspection is completed but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
Disassembly, together with inspection, to verify the full stroke capability of check valves is an option only where full-stroke exercising cannot practically be performed by flow or by other positive means. The NRC staff considers valve disassembly and inspection to be a maintenance procedure that is not equivalent to the exercising produced by fluid flow.
This procedure has risks which may make its routine use as a substitute for testing inappropriate if some method of testing is possible. The licensee should actively pursue the use of non-intrusive diagnostic techniques, such as acoustics, ultrasonics, or magnetics, to demonstrate that these valves open sufficiently during partial flow testing to permit meeting the valves' safety function.
Based on the impracticality of full-stroke exercising these valves i quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternative, relief may be granted from the Section XI requirements provided the licensee performs a partial flow test of the affected valve after valve l
40 l
disassembly and inspection is completed but before returning the valve to service. The licensee should actively pursue the use of non intrusive diagnostic techniques to demonstrate that these valves open sufficiently during partial flow testing to permit meeting their safety function. If another method is developed to verify the full stroke capability of these valves, this relief request should be revised or withdrawn.
3.6 Egaetor Coolant Pressurizer 3.6.1 Cateoory C Valves 3.6.1.1 Relief Reauest. The licensee has requested relief from the remote position indication verification requirements of Section XI, Paragraph IWV 3300, for 434 and 435, the pressurizer safety relief valves, and proposed to verify valve remote position indication during reactor refueling outages by simulating valve actuation by moving the valve's coil.
3.6.1.1.1 Licensee's Basis for Recuestino Relief--These valves are mechanical spring actuated valves. If these valves were actuated for a position indication test, they would need to be retested to ensure the set relief pressure is correct. This involves increased testing and unnecessary radiation exposure to testing personnel.
Alternate Testino: These valves will be simulated to actuate using existing station calibration procedures. The procedure utilizes movement of the valve's coil (up/down) and verifies position via an alarm in the Control Room. Calibration of these position indicators is governed by Plant Technical Specifications and is performed on a refueling basis.
3.6.1.1.2 Evaluation--IWV-3300 requires that valves with remote position indication be observed once every 2 years to verify that valve operation is accurately indicated. Valves 434 and 435 are the pressurizer safety relief valves which are mechanically actuated in response to pressurizer pressure. They are tested in accordance with IWV-3510 which requires setpoint testing at a frequency determined by Table IWV 3510 1, which is generally longer than once every 2 years. Actuating these valves 41
- . . - - -. - - - . ~ - _. - --.
for position indication verification every 2 years would necessitate a retest of the valve's set relief pressure, which would be a hardship for the licensee due to the increased costs and radiation exposure to the test personnel.
The licensee proposed to verify valve remote position indication by moving the valve's coil and observing the appropriate response of the control room indication. This position indication calibration is per the plant Technical Specifications and is performed during each refueling outage.
Although this. procedure does not verify actual valve obturator position, it should give reasonable assurance that valve position is accuratel.y indicated provided that the position _ indication is verified to accurately reflect obturator position during valve setpoint testing.
Based on the determination that compliance with the Code requirements would be a hardship to the licensee without a compensating increase in the level of quality and safety and considering the licensee's proposed testing, relief may be granted from the Section XI requirements provided that valve position indication is verified to accurately reflect obturator position during the valve setpoint testing.
3.7 Safety iniection Svitam 3.7.1 Cateoory A/C Valves 3.7.1.1 Relief Recuest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV-3520, for 842A and 842B, the accumulator discharge check valves, and proposed to part-stroke exercise these valves quarterly and to verify their full-stroke capability by disassembling and inspecting each valve once every ten year cycle.
3.7.1.1.1 Licensee's Basis for Recuestino Relief--Full-stroke open and close exercising during normal power operation cannot be accomplished as system pressures required to perform the test are not enough to overcome RCS pressure. Full-stroke exercising during cold shutdown requires injection into the RCS which could result in low temperature overpressurization of the 42
l .
RCS, nitrogen binding of the RHR pumps, or flooding / radiological contamination if the test is conducted with the reactor vessel head removed.
Also, additional radiological exposure (3 5 person rem) would result and the
] plant would have to be maintained in an unusual condition. Use of freeze plugs or core off loading (with consequential additional radiological exposure and increase in potential fuel handling incidents) would be required.
P:rtial stroke exercising is performed quarterly using the Si test header. Maintenance history and valve disassembly and inspection have shown these valves to exhibit no evidence of excessive degradation.
Alternate Testina: Disassembly of both valves once every ten year cycle.
Each valve shall be disassembled as determined by scheduling and plant conditions. If a valve fails, the remaining valve will be disassembled and inspected for operability at that same time.
3.7.1.1.2 Evaluation lWV-3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, during cold shutdowns. Valves 842A and 842B cannot be full-stroke exercised during power operations because the only full flow path through these valves is from the SI accumulators into the RCS and the accumulators cannot establish flow into the RCS when at normal operating pressures, it is impractical to full-stroke exercise these valves quarterly during power operations unless extensive system modifications, such as installing full flow test loops, are made to permit this testing. It would be burdensome to require the licensee to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert the injection flow away from the RCS.
These check valves cannot be full-stroke exercised by discharging the accumulators into the RCS during cold shutdowns because there is not an adequate expansion volume and injecting into the RCS could cause or contribute to a low-temperature overpressurization of the RCS. Because of this concern and administrative controls to prevent its occurrence, it is impractical to full-stroke exercise valves 842A and 842B during cold 43
shutdowns. Establishing the maximum required accident flow through these valves into the RCS during refueling outages when the vessel head is removed to provide an adequate expansion volume is not practical since this could cause hydraulic damage to the reactor and core components.
The licensee will part stroke exercise these check valves using flow through the Si test header quarterly. This flow rate is less than the maximum required accident flow rate for these valves due to the small diameter piping in this flow path. The licensee has also proposed to disassemble, inspect, and manually exercise the valve disks once each ten year cycle.
Disassembly of each valve once each ten year cycle is a substantial extension of the disassembly frequency which may not be justified from the standpoint of valve reliability arid plant safety. Generic Letter 89 04, Attachment 1, Position 2, states that extension of the valve disassembly /innpection interval should only be considered in cases of extreme hardship where the extension is supported by actual in plant data from previous testing. This Gener i;. !Atter position also identifies information that licensees should develop to support extending disassembly / inspection intervals. It is not clear that RG&E has complied with this Generic Letter position, nor have they justified their. proposed ten year interval.
Therefore, relief should not be granted which extends the disassembly and inspection interval between examining each valve in this group to longer than once every 6 years as discussed in Generic Letter 89 04.
The Minutes of the Public Meeting on Generic Letter 89 04 state that partial-stroke exercise testing with flow is expected to be performed after valve disassembly and inspection is completed but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
The NRC staff considers valve disassembly and in'spection to be a maintenance procedure that is not equivalent to exercising produced by fluid flow. This procedure has risks which make its routine use as a substitute 44
for testing inappropriate if some method of testing is possible. The licensee should actively pursue the use of non intrusive diagnostic techniques, such as acoustics, ultrasonics, or magnetics, to demonstrate that these valves open sufficiently to pass maximum required accident condition flow during a partial flow test at a refueling outage frequency.
Based on the impracticality of full stroke exercising these valves quarterly or during cold shutdowns, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternative, relief may be granted from the Section XI requirements provided the licensee disassembles and inspects these valves at least once every 6 years in accordance with the guidelines of Generic letter 89 04, Attachment 1, Position 2. Also, the licensee should part-stroke exercise the disassembled valve after valve disassembly and inspection is completed but before returning the valve to service. The licensee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves open sufficiently during partial flow testing to permit meeting their safety function. If another method is developed to verify the full stroke capability of these valves, this relief request should be revised or withdrawn.
3.7.1.2 Relief Reouest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for 867A and 8678, the combined SI and accumulator discharge line to RCS cold leg check valves, and proposed to verify the full-stroke capability of these valves by performing a sample disassembly and inspection during refueling outages.
3.7.1.2.1 Licensee's Basis for Reauestina Relief -Full-stroke or part-stroke exercising during normal power operation cannot be accomplished since system pressures required to perform the test are not enough to overcome RCS pressure. Full-stroke exercising during cold shutdown requires injection into the RCS, which could cause low temperature overpressurization of the RCS, nitrogen binding of the RHR pumps, or flooding / radiological contamination if the test is conducted with the reactor vessel head removed.
Also, additional radiological exposure (3-5 person rem) would result and the plant would have to be maintained in an unusual condition. Use of 45
freeze-plugs or core off loading (with consequential additional radiological exposure and increase in potential fuel handling incidents) would be required.
Partial flow exercising is accomplished each refueling by actual safety injection flow into the RCS. Maintenance history and valve disassembly and inspection have shown these valves to exhibit no evidence of excessive degradation.
Alternate Testino: Disassembly of both valves once every ten year cycle.
Each valve shall be disassembled as determined by scheduling and plant conditions. If a valve fails, the remaining valve will be disassembled and inspected for operability at that same time.
3.7.1.2.2 Evaluation--lWV 3520 requires that check valves be exercised to their safety function position (s) quarterly or, if justified, during cold shutdowns. Valves 867A and 8670 cannot be full or part stroke exercised during power operations because the only flow path through these valves is from the SI pumps and accumulators into-the RCS and neither of these sources is capable of establishing flow into the RCS when at normal operating pressures. It is impractical to full-stroke exercise these valves quarterly during power operations unless extensive system modifications, such ar icstalling full flow test loops, are made to permit this testing. It wt.uld be burdensome for the licensee to make such modifications because of tne cost involved. Additionally, reduced system reliability could result from failures that could divert the injection flow away from the RCS.
l These check valves cannot be full-stroke exercised by establishing SI l pump flow and discharging the accumulators into the RCS during cold shutdowns
! because there is not an adequate expansion volume and injecting into the RCS could cause or contribute to a low temperature overpressurization of the l
RCS. Because of this concern and administrative controls to prevent its L
occurrence, it is impractical to full or part-stroke exercise valves 867A and 867B during cold shutdowns. Establishing the maximum required accident flow through these valves into the RCS during refueling outages when the vessel head is removed to provide an adequate expansion volume is not 46
practical since this could c6use hydraulic damage to the reactor and core components.
The licensee will part stroke exercise these check valves using SI pump flow during refueling outages. This flow rate is less than the maximum required accident flow rate for these valves because only one of the two flow sources is utilized. The licensee has also proposed to disassemble, inspect, and manually exercise the valve disks once each ten year cycle.
Disassembly of each vt.lve once every ten year cycle is a substantial extension of the disassembly frequency which may not be justified from the standpoint of valve reliability and plant safety. Generic Letter 89 04, Attachment 1, Position 2, states that extension of the valve disassembly / inspection interval should only be considered in cases of extreme hardship where the extension is supported by actual in-plant data from previous testing. This Generic Letter position also identifies information that licensee's should develop to support extending disassembly / inspection intervals. It is not clear that RG&E has complied with this Generic Letter position, nor have ihey justified their proposed ten year interval.
Therefore, relief should not be granted which extends the disassembly and inspection interval between examining each valve in this group to longer than once every 6 years as discussed in Generic letter 89-04.
The Minutes of the Public Meeting on Generic Letter 89 04 state that partial-stroke exercise testing with flow is expected to be performed after valve disassembly and inspection is enmpleted but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
The NRC staff considers valve disassembly and inspection to be a maintenance procedure that is not equivalent to exercising produced by fluid flow. This procedure has risks which make its routine use as a substitute for testing inappropriate if some method of testing is possible. The licensee should actively pursue the use of non intrusive diagnostic techniques, such as acoustics, ultrasonics, or magnetics, to demonstrate that 47
these valves open sufficiently to pass maximum required accident condition ficw during a partial flow test at a refueling outage frequency.
Based on the impracticality of full stroke exercising these valves quarterly or during cold shutdowns, the burden on the licensee if the Code requirements are imposed, and considering the licensee's proposed alternative, relief may be granted from the Section XI requirements provided the licensee disassembles and inspects these valves at least once every 6 years in accordance with the guidelines of Generic Letter 89 04, Attachment 1, Position 2. Also, the licensee should part strcke exercise the disassembled valve after valve disassembly and inspection is completed but before returning the valve to service. The licansee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves open sufficiently during partial flow testing to permit meeting their safety function. If another method is developed to verify the full-stroke capability of these valves, this relief request should be revised or withdrawn.
3.7.1.3 Relief Reauest, The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV 3520, for 878G and 878J, the check valves in the SI headers to the RCS cold legs, and proposed to full-stroke exercise these valves during refueling outages.
3.7.1.3.1 Licensee's Basis for Reauestina Relief -full or partial stroking during power operation is not possible because safety injection pump discharge pressure is insufficient to overcome reactor coolant system pressure. Exercising during cold shutdowns could cause low temperature overpressurization of the reactor coolant ' tem.
Alternate Testina: These valves will be full stroke exercised during l refueling outages.
3.7.1.3.2 Evaluation--IWV 3520 requires that check valves be f
exercised to their safety function position (s) quarterly if practical or during cold shutdowns. Valves 878G and 878J cannot be full or part-stroke exercised with flow during power operations bec.ause the only flow path 1
l 48 1
through these valves is into the RCS and the SI pumps do not produce sufficient head to overcome normal operating RCS pressure. These valves cannot be full stroke exercised quarterly during power operations unless extensive system modifications, such as installing full flow test loops, are made which permit this testing. It would be burdensome for the licenses to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert injection flow away from the RCS.
Valves 878G and 878J cannot be exercised by pumping into the RCS with the SI pumps during cold shutdowns because the pump shutoff head exceeds the allowable RCS pressure limits for low temperatures and there is not an adequate expansion volume to accor.codate the necessary flow. Thus pumping into the RCS with the Si pumps to full-stroke exercise these valves could cause or contribute to a low temperature overpressurization of the RCS.
Because of this concern and administrative controls to prevent its occurrence, it is impractical to full stroke exercise valves 878G and 878J during cold shutdowns.
The licensee proposed to full-stroke exercise these check valves during refueling outages when an adequate expansion volume exists to accomodate the flow required to exercise them. This testing should give reasonable '
assurance of the operational readiness of these valves and provide an acceptable level of quality and safety.
Based on the impracticality of exercising valves 878G and 878J quarterly or during cold shutdowns, the burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
3.7.2 Cateaory C Valves 3.7.2.1 Relief Reauest. The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV-3520, for 870A, 870B, 889A, and 889B, the SI pump discharge check valves, and proposed 49
4 I
to part stroke exercise these valves quarterly and to full stroke exercise them during refueling outages.
3.7.2.1.1 Licensee's Basis for Reauestino Relief- During operation, the safety injection pump discharge pressure is insufficient to overcome RCS pressure. $1 pump recirculation test line size is insufficient to allow full stroke exercising during operation. Exercising during cold shutdowns could cause low temperature overpressurization of the Reactor Coolant System.
Alternate Testina: These valves will be part-stroke exercised every three months during operation and full stroke exercised during refueling outages.
3.7.2.1.2 Evaluation -lWV-3520 requires that check valves be exercised to their safety function position (s) quarterly if practical, or during cold shutdowns. Valves 870A, 870B, 889A, and 889B cannot be full-stroke exercised with flow during power operations because the only full flow path through them is into the RCS and the SI pumps do not produce sufficient head to overcome normal operating RCS pressure. There is a flow path to establish flow through these valves quarterly during power operations, however, that flow path incorporates small diameter piping that will not permit the passage of sufficient flow to full-stroke exercise the.
valves. Valves 870A, 8708, 889A, and 8898 cannot be full-stroke exercised quarterly during power operations unless extensive system modifications, such as installing full flow test loops, are made to permit this testing. It would be burdensome for the licensee to make such modifications because of the cost involved. Additionally, reduced system reliability could result from failures that could divert injection flow away from the RCS, Valves 870A, 8708, 889A, and 889B cannot be exercised by pumping into the RCS with the SI pumps during cold shutdowns because the pump shutoff head exceeds the allowable RCS pressure limits for low temperatures and there is not an adequate expansion volume to accommodate the required flow. Thus pumping into the RCS with the SI pumps to full-stroke exercise these valves could cause or contribute to a low-temperature overpressurization of the RCS. Because of this concern and administrative controls to prevent its ,
50
occurr'ence, it is impractical to full stroke exercise valves 870A, 8708, 889A, and 889B during cold shutdowns.
The licensee will part stroke exercise these check valves quarterly and full stroke exercise them during refueling outages when an adequate expansion volume exists to accommodate the flow required to exercise them. This testing should provide a reasonable assurance of the operational readiness of these valves.
Based on the impracticality of full stroke exercising valves 870A, 870B, 889A, and 889B quarterly or during cold shutdowns, the burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
3.8 Containment Soray System 3.8.1 .Cateaory A/C Valves 3.8.1.1 Relief Reauest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV-3520, for 862A and 862B, i
.the check valves in the containment spray headers, and proposed to exercise these valves quarterly using a mechanical exerciser and measuring the breakaway force and comparing this force to a reference value established when the valve was known to be in good condition.
l L 3.8.1.1.1 Licensee's Basis for Reauestino Relief -The existing system configuration does not allow' for measurement of pressure differential acting on the disk.
Alternate Testino: Verification of valve movement will be conducted quarterly by measuring and recording the b:eakaway force of the valve and comparing it-to a reference value established when the valve was known to be in good condition. This method is consfstent with guidelines in paragraph 4.3.2.4(b) of ASME/ ANSI OMa-1988, Part 10.
51
3.8.1.1.2 Evaluation It is impractical to full stroke exercise valves 862A and 062B with flow during power operations or any plant operating mode because the only full flow path through these valves is into the
) containment spray rings. Establishing flow through these valves for testing would spray water inside containment which would wet down equipment and structures inside containment and cause damage necessitating extensive repairs and cleanup. The li-ensee has proposed to verify the full-stroke capability of these valves by exercising them with a mechanical operator.
k The Code allows this test method if the force or torque delivered to the disk is measured and compared to the specified acceptance criteria.
The licensee proposed to record the breakaway torque when exercising these valves and compare the measurement to a reference value established when the valve was known to be in good condition.Section XI, Paragraph IWV 3522(b), states that the measured force or torque must be limited to 10%
of the equivalent force or torque represented by the minimum . emergency condition pressure differential acting on the disk, or to 200% of the actual observed force or torque required to perform the exercise on the valve when the valve is new and in good operating condition, whichever is less. The licensee stated that they cannot measure the pressure differential acting on the valve disk, therefore, it is not practicable to determine the proper acceptance criteria and comply with the Code requirements. To meet the Code E
requirements would necessitate making system modifications such as installing test taps and instrumentation. It would be burdensome to require the l
licensee to make these :cdifications.
The licensee's proposal to measure breakaway torque for these valves provides some information about valve condition, but it does not provide assurance that the valves stroke freely through their full travel. The licensee indicated that they measure the force required to exercise these valves to the fully open position by using a calibrated spring gauge attached to the valve position pointer during valve testing. The licensee has not established acceptance criteria for the spring gauge measurement, however, when combined with the breakaway torque measurement with its associated acceptance criteria, this testing should provide reasonable assurance of valve operational readiness and a method of detecting degradation.
52
Based on the determination that it is impractical for the licensee to comply with the Section XI requirements, the burden on the licensee if these requirements were imposed, and considering the adequacy of the proposed alternate testing when complemented by the spring gauge force measurements, reitef may be granted provided tFe licensee continues to measure the running force required to exercise these valves to their fully open position.
3.9 Chemical and Volume Control System 3.9.1 Cateaory B/C Valves 3.9.1.1 Relief Reauest. The licensee has requested relief from the set pressure and seat tightness testing requirements of Section XI, Paragraph IWV 3510, for 392A, an air operated relief valve in the line from the charging pump discharge to RCS loop B hot leg, and proposed to verify that this valve will open at the required differential pressure across the disk and full stroke open during reactor refueling outages.
3.9.1.1.1 Licensee's Basis for Reauestina Relief -Valve 392A is a welded, in line valve and will open with a 250 potnd differential pressure across the disc. Due to its design, set pressure and seat tightness testing L is nc+ appropriate.
Alternate Testina: Valve 392A will be tested in place each refueling outage
- by verifying that it will open and pass the required flow at design l differential pressures.
3.9.1.1.2 Evaluation- Valve 392A functions as a pressure relief valve to protect the charging header from overpressure.- It opens at a set differential pressure across the valve to provide a flow path from the charging system into the RCS loop B hot leg. The valve will reclose after I the differential pressure has decreased below the setpoint. Although this valve functions as a relief valve, it is welded into the system piping and cannot be removed from the system to be bench tested as a relief valve in l accordance with ANSI /ASME OH 1-1981.
. _ __ _ _ _ _ . _ _ __ _ _ _ _ _ _ _ _ . _ . . _ - . ~ ._ _ _ _ _
The licensee's proposal to verify that this valve strokes open at the proper differential pressure and that it passes the required flow rate during each refueling outage should provide reasonable assurance of valve operational readiness. It would be burdensome to require the licensee to
, replace this valve or make system modifications that permit valve removal for bench testing to comply with the Code requirements. These modifications would be costly and would not result in a compensating increase in the level of quality and safety.
Based on the impracticality of testing this valve as specified by ANS1/ASME OM-1 1981, the burden on the licensee if these Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
3.10 Instrument Air Svstem 3.10.1 Cateoory A Valves 3.10.1.1 Relief Reauest. The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV-3410, for the instrument air line containment isolation valve, 5392, and proposed to full-stroke exercise this valve during reactor refueling outages.
3.10.1.1.1 Licensee's Basis for Reauestina Relief--Stroking valve 5392 during operation and cold shutdown is impractical because it would interrupt instrument air to containment and be disruptive to air operated l
l valves inside containment.
Loss of instrument air would cause all air operated valves to be actuated to their fail-safe position. During power operation, this would lead to a reactor trip and during cold shutdowns, this would compromise plant
- operation due to the loss of various components used in maintaining the reactor in a cold shutdown condition.
Alternate Testina: This valve will be full-stroke exercised during refueling outages.
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3.10.1.1.2 Evaluation -This is an air operated valve in the instrument air header that performs a containment isolation function. It would be necessary to isolate the instrument air supply to all equipment inside containment to exercise this valve closed, it is impractical to exercise valve 5392 during power operation because isolating instrument air would result in supplied air operated valves going to their fail safe positions which could lead to a plant trip. It is impractical to perform this testing during cold shutdowns because many components that must function to maintain the reactor in the cold shutdown condition would loose instrument air supply. Further, this testing could result in a delay in returning the plant to power which would be burdensome to the licensee.
The licensee proposed to full-stroke exercise this valve during refueling outages. This testing should give reasonable assurance of valve operational readiness and provide a reasonable alternative to the Code requirements.
Based on the impracticality of complying with the Code requirements, the burden on the licensee if the Code requirements were imposed, and considering the licensee's proposed alternate testing, relief may be granted from the exercising interval requirements of Section XI as requested.
3.11 Overoressure Protection Hitroaen SuDoly System 3.11.1 Cateoory A/C Valves 3.11.1.1 Relief Recuest. The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV-3520, for 8606A and 8606B, the supply check valves for the overpressure protection system nitrogen accumulators, and proposed to verify their reverse flow closure in conjunction with the ASME Section XI leak rate testing during refueling outages.
3.11.1.1.1 Licensee's Basis for Reauestina* Relief--When these valves are in operation, there is no practical means to test valve closure.
Valve closure cannot be verified due to system design. To perform a closure 55
verification constitutes a leak test which presents a significant hardship during cold shutdown. Leak testing requires an extended period of time where the overpressure protection system would be out of service.
Alternate Testino: Valve closure verification will be performed in conjunction with ASME XI leak tests conducted during refueling outages.
3.11.1.1.2 Evaluation 8606A and 860GB are simple check valves which are not equipped witn position indication. The only practical method available to verify closure of these valves is to perform a leak test. Leak testing would require isolation of the nitrogen supply to the RCS overpressure protection system accumulators. This system is only in service during cold shutdowns to prevent exceeding the RCS pressure limits for low temperature operation so the reactor vessel and other system components do not suffer brittle fracture. Isolating the nitrogen supply to test these valves during cold shutdowns could result in the pressurizer power operated relief valves (PORVs) being unable to perform their safety related function.
These valves are located inside containment and leak testing them requires access to the containment and could result in high radiation exposures and other safety hazards to test personnel, it would be burdensome to require the licensee to comply with the Code requirements due to the high costs involved and the potential safety hazards to test personnel.
The licensee proposed to verify closure of these valves during performance of leak rate testing at reactor refueling outages. This testing should provide reasonable assurance of the ability of these valves to perform their safety function in the closed position.
Based on the determination that compliance would result in hardship to the licensee without a compensating increase in the level of quality and safety and considering the licensee's proposed alternate testing, relief may be granted from the exercising interval requirements of Section XI as requested.
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e 3.11.2 Cateoory B Valves 3.11.2.1 Relief Recuest. The licensee has requested relief from the stroke time measurement requirements of Section X'4, Paragraphs IWV 3413 and 3417, for 8616A, 8616B, 8619A, and 8619B, the solenoid control valves that provide nitrogen to cycle the PORVs, and proposed to verify valve operational readiness by observing proper operation of the PORVs when they are tested during plant shutdown.
3.11.2.1.1 Licensee's Basis for Recuestino Relief These are rapid-acting v9ves whose design prohibits visual observance cf stroking.
These valves do not have remote position indicators. PORV strake times are affected by stroke times of 8616A, 8616B, 8619A and 86198, Alternate Testino: Valve stroke testing is performed during plant shutdown in conjunction with PORV overpressure protection testing. Valve stroking parameters will be considered acceptable if the associated PORV cycling is acceptable. If the PORV failed to operate, due to other identified malfunctions, nitrogen valve stroking parameters will be considered acceptable and reverified during a retest following PORY corrective action.
3.11.2.1.2 Evaluation -These valves are totally enclosed solenoid operated valves which have no externally visible indication of valve position. It is impractical to measure the stroke times of these valves because there is no way to determine when a valve receives an actuation signal or when it completes its travel. These valves are rapid-acting valves which normally stroke almost instantly and when they do not operate promptly, they most commonly fail to operate at all.
These valves function to admit nitrogen to the pressurizer PORVs to open them, therefore, it can be indirectly verified that each valve has actuated by monitoring the operation of the pressurizer PORVs. Measuring the stroke times of a PORV provides indication of solenoid operated valve degradation since any significant increase in solenoid valve stroke time would result in longer PORV stroke times and may result in the PORV exceeding its stroke time limit.
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The full stroke times of these solenoid valve cannot be measured unless significant system modifications, such as replacing the valves with ones having disk position indication, are made to permit this testing. Replacing these valves to permit stroke time measurements would provide little additional information above that generated by the proposed alternate testing, it would be burdensome for the licensee to make such modifications due to the high costs involved and the minimal amuunt of additional information that would be obtained.
Based on the determination that it is impractical to measure the stroke times of these rapid-acting solenoid valves, that compliance with the Code requirements would be burdensome to the licensee, and considering the licensee's proposed alternate testing of measuring the PORV stroke times, relief may be granted from the Code requirements as requested.
3.12 Emeraency Diesel Generator Fuel Oil Transfer System 3.12.1 Cateaory B Valves 3.12.1.1 Relief 3AhM111 The licensee has requested relief from the stroke time measurement requirements of Section XI, Paragraphs IWV 3413 and
-3417, for 5907, 5907A, 5908, and 5908A, the solenoid control valves that direct diesel fuel oil flow either to the day tanks or back to the diesel oil storage tanks, and proposed to verify proper valve operability by observing their operation during quarterly diesel testing, but stroke times will not be measured for these valves.
3.12.1.1.1 Licensee's Basis for Reauestina Relief--These are rapid acting solenoid valves whose design prohibits visual observation of stroking as there are no external indicators on these valves. These valves are automatically actuated as necessary based upon diesel oil day tank levels. These valves do not have control switches. Diesel generators are tested monthly (per Tech. Specs.), during which these valves actuate for filling the day tanks and for diesel oil recirculation. No history of diesel generator testing failure has been attributed to performance of these valves.
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Alternate Testino: Measurement and evaluation of stroke time shall not be performed. These valves shall be exercised and fail safe tested at least quarterly during diesel generator testing. Valve stroking parameters will be considered acceptable based upon satisfactory actuation as demonstrated by adequate fuel flow during the D/G tests.
3.12.1.1.2 Evaluation These valves are totally enclosed solenoid operated valves which have no externally visible indication of valve position, it is impractical to measure the stroke times of these valves because there is no way to determine when a valve receives an actuation signal or when it completes its travel. These are rapid acting valves which normally stroke almost instantly and when they do not operate promptly, they most commonly fail to operate at all.
in order to obtain meaningful stroke times for these valves it would be necessary to replace them with valves having position indication or to develop some other means of determining valve position. It would be burdensome to require the licensee to replace these valves since it would be costly. However, the licensee's proposal provides no means of detect %g valve degradation. Some means should be developed to measure the full-stroke time of these valves to monitor valve condition and detect degradation. Even if these valves are not replaced with ones having position indication, it may be possible for the licensee to develop a method of measuring stroke times, such as using non intrusive diagnostic techniques. If stroke times determined by such an alternate method are not sufficier tly repeatable to permit trending, the licensee could classify these valve; as rapid-acting valves or, if that isn't practical, establish an appropriate maximum stroke time limit using the guidelines of Generic Letter 89-04, Attachment 1, Position 5, and verify that stroke times remain under this limit. It would be burdensome to require the licensee to immediately develop a means of monitoring for valve degradation, therefore, an interim period should be provided for the licensee to develop a method of performing this testing.
The licensee's proposal of verifying valve operational readiness by quarterly exercising and fail-safe testing should provide an acceptable level of quality and safety during the interim period.
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1 Based on the impracticality of measuring valve full stroke times, the burden on the licensee if the Code requirements are imposed, and considering the licensee's proposed alternate testing, interim relief may be granted for 12 months. During this interim period the licensee should develop a method of adequately monitoring for degradation of these valves.
3.12.2 Cateoory C Valves 3.12.2.1 Relief Recuest. The licensee has requested relief from the exercising requirements of Section XI, Paragraph IWV 3520, for 5960A and 5960B, the check valves in the diesel day tank overflow lines back to the diesel oil storage tanks, and proposed to verify valve operational readiness by performing a sample disassembly and inspection during refueling outages.
3.12.2.1.1 Licensee's Basis for Reauestina Relief- During operation there is no practical means to exercise these valves. Valve closure cannot be verified due to system design. To perform a closure verification would require disassembly of mechanical joints in the piping, which would place the diesel in an inoperable condition.
NOTE: In their letter dated March 14, 1990, the licensee stated that the safety function performed by valves 5560A and 5960B is to provide overpressure protection for the fuel oil day tank and that disassembly will be performed to verify forward flow.
Alternate Testina: One valve will be disassembled, full-stroke exercised and inspected each refueling outage on a rotating basis. If that valve fails, the remaining valve will be disassembled, full stroke exercised and inspected for operability during that same outage. (re, Generic letter 89-04, Attachment 1 - Position 2) 3.12.2.1.2 Evaluation--These are 1 1/2 inch swing check valves located in the overflow lines for the diesel generator fuel oil day tanks.
Exercising these valves open with flow requires overfilling the day tank to establish flow through the overflow line. To overfill the day tank, it would be necessary to install jumpers or otherwise defeat the day tank level controller. It may not be prudent to override plant control functions and 60
challenge the operation of safety equipment in order to perform this testing. Failure of one of these check valves to open during this postulated test could result in rupture of the day tank which could render the diesel generator inoperable. Therefore, it is impractical to exercise these valves open with flow at any frequency, in order to test these valves to the Code requirements the licensee would have to make system modifications such as installing test operctors on these valves or replacing them with testable valves. It would be burdensome to require the licensee to make these modifications due to the high costs involved.
Generic letter 89-04, Attachment 1, Position 2, states that valve disassembly and inspection can be used as a means of determining that a valve will full stroke exercise open. The Minutes of the Public Meeting on Generic Letter 89-04 fPther state that part stroke exercise testing with flow is expected to be performed after the disassembly and inspection is completed but before returning the disassembled valve to-service. The part-stroke exercise is important after disassembly to provide an indication that the valve has been reassembled correctly and that the valve is operable, in this situation, it is impractical to establish flow through these valves or to leak test them, therefore, there is no practicable method to obtain an indication that the valves have been reassembled properly. For this reason, the licensee should not continue disassembly and inspection of these valves as a long term alternative to the requirements of Section XI unless they can determine a practical method of exercising these valves after they have been reassembled.
Based on the determination that it is impractical to full-stroke exercise these valves with flow at any frequency and considering that the licensee proposed to disassemble and inspect them in accordance with Generic Letter 89-04, Attachment 1, Position 2, interim relief may be granted for one year or until the next refueling outage, whichever is longer. This relief is acceptable on an interim basis since the disassembly and inspection does provide a form of valve exercising and the likelihood of improper reassembly in the interim is low. During this interim period, the licensee should take actions to allow Code testing or at least part-stroke exercising of these valves after reassembly, or che licensee should take other actions to remedy this situation.
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3.13 Main Feedwater Systen
_ 3.13_.1 Cateaory- C Valves ' l
- 3.13.1.1 Relief Raouest. The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IW 3520.-for 3992 l
and 3993, the main feedwater header check valves, and proposed to verify the 4 reverse' flow closure of these valves during the shutdown process for those j cold shutdowns that are not initiated by a plant trip and during refueling; outages.
3.13.1.1.1 . Licensee's Basis for Reauestina Relief During operation-there is no practical means to exercise these . valves. During normal plant shutdown to cold shutdown, these valves are tested when feedwater flow is transf6rred to the auxiliary feedwater system. During cold-shutdowns resulting-from-a plant trip, valves 3992 and 3993 cannot be exercised due to system operating conditions.
Alternate Testino: If the valves cannot.be testing during normal cold I shutdown they will be tested for closure:during refueling outages. 4 3'.13.1.1.2 Evaluation--!W-3520 requires-that check valves be-exercised to their safety function position (s) quarterly, if practical, or.-
during cold shutdowns. It would be necessary to isolate feedwater to a steam generator in order.to exercise one of these valves closed, and isolating
. feedwater flow during power operations would result in loss of steam. .;
_ generator. level control.which could cause a plant trip. Since this testing: 1 would.cause a plant transient which could lead to a plant trip, it is not-
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I considered to be practical during power operations..
These valves'do not have position indication or a means to force the obturator to the closed position. Therefore, the only practical non-intrusive methods available to verify valve closure during cold shutdowns :
-and refueling outages are leak testing and observing a differential pressure E
across the valves.' A system modification such as replacing these valves with ones that have position indication would be necessary to comply with the Code h 62
{ - - -- - - - . .:
requirements. It would be burdensome to require the licensee to make the necessary modifications due to the high costs involved.
The licensee has proposed to verify valve closure during normal cold shutdowns and during refueling outages. Due to the time required to get personnel in place and set up special test equipment, it is not practical to perform this testing during those cold shutdowns initiated by a plant trip.
The licensee's proposed testing should give reasonable assurance of the ability of these valves to perform their safety function and provide an acceptable alternative to the Code required testing.
Based on the impracticality of exercising valves 3992 and 3993 quarterly or during those cold shutdowns that are initiated by a plant trip, the burden on the licensee if these Code requirements were imposed, and the licensee's proposed alternate testing, relief may be granted from the Section XI requirements as requested.
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APPENDIX A IST PROGRAM AN0MAllES 10ENTiflED DURING THE REV!EW m
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APPENDIX A IST PROGRAM AN0MAllES 10ENTIFIED DURING THE REVIEW Inconsistencies and omissions in the licensee's program noted during the course of this review are sumarized below. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
- 1. The licensee has requested relief from the in:trument full-scale range requirements of Section XI for the vibration instruments used for IST of safety-related pumps and proposed to use vibration detectors with multiple overlapping reales. Relief may be granted provided that the accuracy of the vibration instruments, on the scales used for vibration measurements, is equivalent to that provided by a single scale instrument that complies with the requirements of IWP 4110 and -4120.
(Refer to TER Section 2.1.2)
- 2. The licensee has requested relief from the flow rate measurement requirements of Section XI for the diesel generator fuel oil transfer pumps (PDG02A and B) and proposed to determine pump flow rate by measuring the change in day tank level versus time. Relief may be granted from the Code requirement as requested provided that the licensee complies with the Allowable Ranges and Corrective Actior.
requirements specified in IWP-3200. (Refer to TER Section 2.2.1)
- 3. The licensee has requested relief from the flow rate measurement requirements of Section XI for the service water pumps (PSWO 1A, 1B, IC, and 10) and proposed to measure the flow rate in the containment fan cooler outlet lines. Relief may be granted from the Section XI requirements provided the licensee establishes repeatable test conditions which permit obtaining data that is meaningful for detecting pump degradation. (Refer to TER Section 2.4.3)
- 4. The licensee has requested relief from the stroke time measurement requirements of Section XI for hand control valves which operate using a A-3
variable set air signal and proposed to verify valve operability during ,
quarterly exercising,'but the licensee has proposed to not measure the stroke times for these valves. The licensee's proposal provides no q means of detecting valve degradation. Interim relief may be granted for-112 months, during which the lice 1see'should develop an adequate means to monitor for degradation of these valves.- (Refer to TER Section 3.1.6.1)
- 5. The-itcensee- has requested relief from the stroke -time evaluatio' n and corrective. action requirements of.Section XI and proposed'to follow a
_ plan based-.on deviation from a reference. stroke time instead of the- 1
, -s previous. test' stroke time. Generic 1.etter 89 04, Attachment 1, Position 6, states the NRC staff position on basing stroke time ~;
corrective actions on deviations from reference values. The licensee's proposed testing _ appears to be in compliance with this ?Uition, therefore, relief may be granted provided the licenset fr4Iows all-of-the-criteria of_.the Generic letter position. (Refer to TER
$ Section 3.1.7.1)
- 6. - The-licensee has requested relief from the exercising frequency and test method requirements of Section XI for the emergency diesel generator air start accumulator check valves, 5941A~ and 5942A, and proposed to verify the reverse' flow closure capability of-these valves by disassembly _ and inspection on a sampling basis-during refueling outages.-;The licensee o has not:shown the-impracticali_ty of verifying-the rsverse' flow closure
-of these valves by leak-testing during. refueling outages, therefore,
-disassembly and-inspection.should not' be amployed on.a long term basi _s in this situation. InterimLrelief may be. granted for one year or until the' end of the next refueling outage, whichever is longer. During this
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interim period, the licensee should develop a method to verify the reverse flow closure capability of. these valves other than disassembly.
(Refer to TER Sectio.n 3.2.2.1)
- 7. :The licensee has requested relief from the-stroke time measurement-requirements of Section XI for the isolation valves in the auxiliary
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? feedwater and standby auxiliary feedwater pump recirculation-lines, 4291, 4304,.4310, 9710A, and 97108, and proposed to exercise these
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valves to verify their operab' f.ty however, valve stroke times will not be measured. The licensee's proposal provides no means of detecting i valve degradation. Interim relief may be granted for 12 months, during which the licensee should develop an adequate means of monitoring for degradation of these valves. (Refer to TER Section 3.4.1.1)
- 8. The licensee requested relief from the exercising requirements of I Section XI for 9627A and 9527B, the check valves in the service water line to the standby auxiliary feedwater pump suctions, and for 4001, 4602, 4603 and 4604, the service water pump discharge check valves, and l proposed to part stroke exercise these valves quarterly and to partially disassemble, inspect, and manually full stroke exercise them on a sampling basis during refueling outages. Relief may be granted from the Section XI requirements provided the licensee performs a partial flew test of the affected valve after valve disassembly and inspection is completed but before returning the valve to service. The licensee should actively pursue the use of non intrusive diagnostic techniques to demonstrate that these valves open sufficiently during partial flow testing to permit meeting their safety function, if another method is developed to verify the full stroke capability of these valves, this relief request should be revised or withdrawn. (Refer to TER Sections 3.4.2.1 and 3.5.2.1)
- 9. The licensee has requested relief from the exercising requirements of Section XI for 4023, the check valve in the recirculation flow path of the turbine driven auxiliary feedwater pump, and proposed to verify the full stroke capability of this valve by disassembly and inspection during each refueling outage. The licensee committed to installing flow rate instrumentation in the turbine driven auxiliary feedwater pump recirculation flow path during the 1990 refueling outage which will permit verifying a full stroke exercise of valve 4023 quarterly.
Interim relief may be granted from the Section XI requirements until the system modification to install flow rate instrumentation has been completed. (Refer to TER Section 3.4.2.2)
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- 10. The licensee requested relief from the stroke time ne'asurement requirements of Section XI for 4324, 4325, and 4326, the solenoid operated valves in the service water lines to the auxiliary feedwater pump bearings, and proposed to exercise these valves quarterly to verify their operational readiness, but the stroke times will not be measured for these valves. The licensee's proposal provides no means of detecting valve degradation. Interim relief may be granted for 12 months, during this period the itcensee should deveiop an adequate means to monitor for degradation of these valves. (Refer to TER Section 3.5.1.1)
- 11. The licensee requested relief from the remote position indication verification requirements of Section XI for 434 and 435, the pressurizer safety relief valves, and proposed to verify valve remote position indication during reactor refueling outages by simulating valve actuation by moving the valve's coil. This position indication calibration is per the plant Technical Specifications. Although this procedure does not verify actual valve obturator position, it should give reasonable assurance that valve position is accurately indicated provided that the position indication is verified ta accurately reflect obturator position during valyc setpoint testing. Therefore, relief may be granted from the Section XI requirements provided that valve position indication is verified to accurately reflect obturator position during the valve setpoint testing. (RefertoTERSection3.6.1.1)
- 12. The licensee requested relief from the exercising requirements of Section XI for 842A, 8428, 867A, and 8678, the accumulator discharge check valves and combined accumulator / safety iiijection pump check valves, and proposed to part stroke exercise these valves quarterly and to verify their full stroke capability by disassembling and inspecting each valve once every ten year cycle. Generic Letter 89 04, Attachment 1, Position 2, states that extension of the valve disusembly/ inspection interval should only be considered in cases of extreme hardship where the extension is supported by actual in plant data from previous testing. This Generic letter pctition identifies information that licensee's should develop to suppo t estanding I
l disassembly / inspection intervals. it is not clear that RGtE has complied with this Generic Letter position, nor have they justified their proposed ten year interval. Therefore, these valves should be disassembled and inspected so that the interval between examining each valve is not longer than once every 6 years as specified in Generic Letter 89 04, or the licensee should verify that these valves move to their fully open position by use of non intrusive diagnostic techniques while performing a reduced flow test at least once every refueling outage. (RefertoTERSections3.7.1.1and3.7.1.2).
- 13. The licensee has requested relief from the exercising requirements of Section XI for 862A and 8628, and proposed to exercise these valves quarterly using a mechanical exerciser and measuring the breakaway force and comparing this force to a reference value established when the valves were known to be in good condition. The licensee's proposal does not provide assurance that these valves stroke freely through their full travel. The licensee indicated that they measure the force required to exertise these valves to the fully open position by using a calibrated spring gauge attached to the valve position pointer during valve testing. Relief may be granted as requested provided the licensee continues to measure the running force required to exercise these valves to their fully open position. (RefertoTERSection3.8.1.1)
- 14. The licensee requested relief from the stroke time measurement requirements of Section XI for 5907, 5907A, 5908, and 5908A, and proposed to verify proper valve operability by observing their operation during quarterly diesel testing, but stroke times will not be measured for these valves. The licensee's proposal provides no means of detecting valve degradation. Interim relief may be granted for 12 months, during this period the licensee should develop a method to monitor for valve degradation. (RefertoTERSection3.12.1.1)
- 15. The licensee requested relief from the exercising requirements of Section XI for 5960A and 59608, the check valves in the diesel day tank overflow lines back to the diesel oil storage tanks, and proposed to verify valve operational readiness by performing a sample-disassembly l
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and inspection during refueling outages. The Minutes of the Public Meeting on Generic Letter 89 04 state that partial stroke exercise testing with flow is expected to be performed after disassembly and inspection is completed. In this situation, it is impractical to establish flow through these valves or to leak test them, therefore, there is no practicable method to obtain an Indication that the valves have been reassembled properly. For this reason, the licensee should not disassemble and inspect these valves to meet the requirements of Section XI uniess they can determine a practical rathod of exercising these valves after they have been reassembled. Interim relief may be granted until the next refueling outage. After this interim period, the licensee should either be able to adequately test these valves or take other actions to remedy this situation. (Refer to TER Section 3.12.2.1)
- 16. Cold shutdown justifications CS 5, CS 16, and CS 30 identify test frequencies other than during cold shutdowns which makes the cold shutdown justifications inappropriate for the affected valves. The valves addressed in these justifications are all included in relief requests (VR 21, VR 3, VR 14, and VR 20) which are evaluated in the body of this TER. Since the affected valves are all covered by relief requests, it is not necessary nor appropriate to include them in these cold shutdown justifications.
- 17. The licensee has not provided an adequate technical basis in cold shutdown justification CS 12 to demonstrate the impracticality of quarterly exercising valves 813 and 814, the component cooling water supply and return valves to the reactor support coolers. The licensee stated that exercising these valves would isolate cooling flow which could result in thermal stress to the reactor vessel supports. it is not clear that the time required to exercise these 6 inch motor operated valves would be sufficient to cause thermal stress in the supports. The licensee should exercise these valves quarterly or revise this cold shutdown justification to demonstrate that valve stroking is indeed
, impractical.
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- 18. In cold shutdown justification C5 20 the licensee stated that valve 8419 is normally closed during power operation and is not required to change position to perform its safety function. The licensee listed 8419 as an
' Active' Category A/C valve in their IST program. If this valve is ever i
open during power operations, it would have to change position to l perform its containment isolation safety function in the closed position i and would be correctly classified as ' Active." In this case valve 8419 should be exercised quarterly to demonstrate its operational readiness,
- 19. In cold shutdown justification CS 29 the licensee stated that valves 9227 and 9229 are normally closed during power operation and are not required to change position to perform their safety function. The licensee listed 9227 as an ' Active' Category A valve and 9229 as an
' Active" Category A/C valve in their IST program. If these valves are ever open during power operations, they would have to change position to perform their containment isolation safety function in the closed position and would be correctly classified as ' Active.' In this case these valves should be exercised quarterly to demonstrate their operational readiness.
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