ML20058L041
| ML20058L041 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/31/1990 |
| From: | Hartley R EG&G IDAHO, INC. |
| To: | NRC |
| Shared Package | |
| ML17056B078 | List: |
| References | |
| CON-FIN-A-6812 EGG-NTA-8974, TAC-63429, NUDOCS 9008060069 | |
| Download: ML20058L041 (63) | |
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EGG-NTA 8974 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM NINE NILE POINT, UNIT 2
' Docket No. 50 410 R.'S. Hartley.
C. B. Ranson Published August 1990' Idaho National Engineering Laboratory -
EG&G Idaho, Inc.
Idaho Falls, Idahoi 83415 Prepared for the U.S. Nuclear Regulatory Comission Washington, D.C. -20555 Under DOE Contract No. DE-AC07-761001570-FIN No.-A6812:
TAC No.-'63429~
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CONTENTS 1
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l ABSTRACT ............................................................... 11 PREFACE ............................................................... 11 1.
INTRODUCTION ..................................................... 1 i 1
2.
SCOPE ............................................................. 3 !
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PUMP TESTING PROGRAM ............................................. 7 !
- 3. l' General Pump Relief Requests ............................... 7 1
3.1.1 Rel ie f Reques t . . . . . . . . . . . . . . . .
3.1.2 Relief Request ................ ....................
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3.2 Standby Liquid Control System .............................. 10 3.2.1 1 Re l i e f Reque s t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
... l 3.3 Service. Water System ...................................... 12.
3.3.1 Re l i e f Reque s t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 ....
4.
VALVE TESTING PROGRAM ............................................ 15 4.1 General Val ve Rel ie f Requests . . . . . . . . . . . . . . . . . . ... . . . . . .15. . . .
4.1.1 4.1.2 Containment Isolation Valves ........................
Excess Flow Check Valves .. 15 ,
4.1.3 Rapid-Acting Valves ................................- 17 4.1.4 Keep Fill Check Valves'.......
..................... 18
..................... -20 4.2 Diesel Generating System ................................... 21 4.2.1 Category 8 Valves .......
4.2.2 Category C Valves ....... ..........................- 21
.......................... 22 .
4.3 Feedwater System ........................................... 24 4.3.1-C a t ego ry A/C ' Va l ve s . . . . . . . . . . . . . . . . . . . . . . . . . 24 ........
4.4 Nitrogen System ............................................ 25 4.4.1 Ca t ego ry A/C Val ve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 ....
4.5 Instrument Air System ...................................... 26 4.5.1 Category A/C Valves ................................ 26 111 1
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i a e TECHNICAL EVALUATION REPORT PVMP AND VALVE INSERVICE TESTING PROGRAM NINE MILE POINT UNIT 2
- 1. INTRODUCTION 1
Contained herein is a technical evaluation of the pump and valve. I inservice testing (IST) program submitted by Niagara Mohawk Power Corporation for its Nine Mile Point, Unit 2. I By a letter dated July 30, 1987, Niagara Mohawk Power Corporation submitted Revision 0 of their IST Program for Nine Mile Point, Unit 2, for 1 I
4 their 1st 10 year testing interval, which commenced October 31, 1986.. A working meeting with Niagara Mohawk Power Corporation and Nine Mile Point, Unit 2, representatives was conducted December 3 and 4, 1987. The licensee's IST Program for pumps and valves, Revision 1, as revised by; Niagara Mohawk Power Corporation and attached to C. V. Mangan letter to I NRC, dated March 31, 1988, in addition'to minor revisions dated-September 30, 1988 and February 8, 1989, was reviewed to verify compliance i 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, 1983 Edition through Summer 1983 Addenda. Any IST program 3 revisions subsequent to those noted above are not addressed in this
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i technical evaluation report (TER). Any successive program changes should be prepared in accordance with the guidance of. Generic Letter No. 89-04,
" Guidance on Developing Acceptable Inservice Testing Programs."
In their submittals, Niagara Mohawk Power Corporation has requested ,
relief from the.ASME Code testing requirements for. specific. pumps and- l valves and these requests- have been evaluated individually to determine if-the criteria in 10 CFR 50.55a for granting relief hastbeen met.- This' '
review was performed utilizing the acceptance criteria of the Standard Review Plan, Section 3.9.6, and the Draft Regulatory Guide and Value/ Impact Statement titled " Identification of Valves for InclusionLin. Inservice Testing Programs", and Generic Letter.No. 89-04, " Guidance on Developing' Acceptable Inservice Testing Programs." The'IST Program testing:
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2; SCOPE l
2 The EG&G Idaho review of the Niagara Mohawk Power Corporation, Nine Mile Point, Unit 2 inservice testing (IST)-program for pumps and. valves was begun in 1987.
The program initially ~ examined was Revision'0, dated July 30, 1987, which identified the licensee's proposed testing of !
safety-related pumps and valves in the plant systems listed in Appendix B. !
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The licensee's proposed IST program was reviewed by locating and I highlighting the components on the appropriate system P& ids ana' determining their function in the system. Then the licensee's proposed testing was
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evaluated to determine if it was in compliance with the ASME_ Code,Section XI, requirements. During the course of this review,' questions and '
comments were made relative to unclear or potential problem areas in_the licensee's IST program.
These were transmitted to the licensee in the form of a request for additional information _ (RAl) which served as the agenda j for the working meeting between_the licensee, the NRC, and the EG&G reviewers.
Each pump and valve relief request was individually evaluated to '
determine if the licensee had clearly demonstrated 'that the Code requirements are impractical for the identified system components, and to
( determine if the proposed alternate testing'would provide a reasonable
' indication of. component operability giving due consideration to;the burden on the licensee if the Code requirements weresimposed.- Where the licensee's technical basis or alternate testing.was_ insufficient or unclear, the . licensee was requested to clarify the -relief; request - The system P&ID was also examined to determine whether'the instrumentation necessary to make the identified measurements was:available. If,-based on the unavailability of adequate. instrumentation or the reviewers: experience
-and system knowledge, it was determined that it'may not be possible or practical to make the measurements identified in the-licensee's .IST q
I program, a question or comment was generated requesting clarification.
Fo. pumps, it was verified that each of the seven inservice. test !
quantities of Table IWP-31001 was indicated to be measured or observed. 4 3
l Further evaluation was performed on all valves in the program to determine that the identified testing could practically and. safely be
! conducted as daccribed. If the licensee's ability to perform =the testing was in doubt, a question was formulated to alert the licensee to the suspected problem. l l
l Safety related safety valves and relief valves, excluding those that .
perform only a thermal relief function, were confirmed to be included in I the IST program and tested in accordance with IWV-3510. ' Safety-related' explosively actuated valves were verified to be included-in the IST program and tested in accordance with IWV-3610. ,
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- Once all the components in the licensee's IST program had been y identified on the P& ids and evaluated as described above, the P& ids were examined closely by at least two trained and experienced reviewers to identify any additional pumps
- or valves that may perform _ a safety function -
which were not included in the licensee's program. The. licensee'was asked to reconcile any' components that were identified by this process'which were- !
not included in the IST program. Also, the list of systems included in the licensee's program was compared to a system. list in the. Draft Regulatory Guide and Value/ Impact Statement titled, " Identification of Valves for-Inclusion in Inservice Testing Programs". ' Systems-that appear in the Draft Regulatory Guide list but not in-the licensee's program were-evaluated and, if appropriate, questions were added to thelRAI.
l Additionally, if the reviewers suspected;a specific or a general aspect
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l of the licensee's IST program based on their past-experiences', questions l were included'in the RAI.to clarify those. areas of doubt. Some'questio's n ,
were included for the purpose of- allowing the reviewers to make conclusive
- statements in this TER.
i At the completion of-the review, the RAI was= transmitted to the~-
1icensee. These questions were 1ater used as the agenda.for~the working- t meeting with the licensee on December 3 and 4, 1987. At the, meeting,3each t
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- 3. PUMP TESTING PROGRAM l The Nine Mile Point, Unit 2, IST program submitted by the Niagara Mohawk Power Corporation was examined to verify all pumps that are included are subjected to the periodic tests required by the ASME Code,Section XI, 1983 l Edition through Summer 1983 Addenda, except for those pumps identified below for which specific relief from testing has been requested and is summarized in 1 Appendix B. Each Niagara Mohawk Power Corporation basis for requesting relief
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from the pump testing requirements and the reviewers'-evaluation of that request i: summarized below.
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3.1 General Pumo Relief Reauests ,
k 3.1.1 &L11af Reauest i
The licensee has requested relief from measurement of pump vibration
- amplitude in units of displacement in accordance with the requirements of Section XI, Paragraph IWP-4500, for all pumps in~the IST program and has proposed to measure pump vibration in-units of' velocity utilizing the .
Acceptance Criteria listed below.
3.1.1.1 Licensee's Basis for Reauestina Relief. T:NMP2 proposes an- i alternate program which, based on survey conducted of-exisi!ing plants vibration programs and a review of pump vibration testing literature, provides l
a significant increase in the predictive capability, iThe proposed program is based on vibration readings measured in velocity. units rather than vibration
- amplitude in mils displacement. This technique is an' industry accepted method' which is more. sensitive.to small changes that are. indicative of. developing.
mechanical problems and hence more meaningful. Velocity measurements, in.
addition to detecting high amplitude vibrations that indicate a major-mechanical problem, provide an improved ability to. detect equally harmful i low-amplitude, high-frequency vibrations resulting from misalignment,
) imbalance, or bearing wear _that usually go' undetected by simple displacement measurements..
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,, 3.1.1.2 Evalua t ion.~
Utilizing vibration velocity measurements rather than vibration displacement measurements has been demonstrated to provide l
better indication of degradation for most' safety related pumps, The-vibration monitoring program in ANS!/ASME OMa 1988, Par.t 6.-has been.
determined by NRC to be acceptable as an alternative to the requirements of Section XI, Paragraph IWP-4510.
The licensee's proposed alternative appears to be in accordance with the Part 6 vibration measurement requirements.
Therefore, the licensee's proposal gives adequate assurance of operational readiness and provides a reasonable. alternative.to the Code requirements.
Based on the determination the. licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted from the' Code requirements as requested provided the licensee complies with all the vibration measurement requirements of-0Ma 1988, Part 6.
3.1.2 Relief Recuest_ i The licensee has requested relief from measurement:of pump. bearing j
temperature for all pumps in the IST: program in'accordance with the requirements of Section XI, Paragraph IWP-4310, and has proposed to determine the mechanical condition of these pumps utilizing quarterly vibration monitoring.
3.1.2.1 Licensee's Basis-for Reouestino Relief. .The measuring of bearing temperatures along with vibration monitoring are both means of determining the' mechanical condition of a pump. However, the condition of a pump bearing would have to ,er.iously degrade to cause a detectable rise-of temperature:on the bearing housing. With the improved vibration.
monitoring prcgram employed at NMP2, the ability to detect very'small.
changes in the mechanical condition of a pump exists. Therefore, any-degradation of.a bearing would.be detected before an increase of temperature on the bearing housing occurred..
. Alternative Testino:
Pump mechanical l condition will be determined'by-quarterly-vibration monitoring. -Bearing temperatures will not be measured.
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accordance.with the requirements of Section XI, Table IWP 4110 1, and proposed to measure flow rate with an ultrasonic flow meter with' a 1 full-scale repeatable accuracy of 13%.
1 3.2.1.1 Licensee's Basis for Reauestina Relief. These pumps test circuits are not provided with in-place flow meters. Flow measurement for these pumps will be accomplished by use of'a clamp on ultrasonic flow meter 4 with a full scale repeatable accuracy of 3 percent. The 3 percent accuracy exceeds the allowable instrument accuracy contained in Table IWP-4110 1, however, this small reduction in' accuracy will not provide a significant reduction in the ability to determine pump operability. NMPC will continue to evaluats industry development of more accurate instrumentation.
Alternative Testina: Flow rate will be. measured using a clamp on ultrasonic flow meter with a repeatable full ~ scale accuracy of 3 percent, q
3.2.1.2 Evaluation. These pumps inject a borated solution into the reactor coolant system for emergency shutdown. The test flow path for these pumps does not have installed flow instrumentation.- Installation of permanent instrumentation to facilitate. meeting the Code requirements would require system redesign and would pose a significant hardship on the licensee. The licensee has propcsed to utilize clamp on type ultrasonic flow rate meters to determine flow rate with full-scale. accuracy of.
3 percent, which may be less accurate than_ required by the Code -
(2 percent). However, the slight difference in instrument accuracy i
obtained by complying with the Code requirements would not' materially increase the licensee's ability to evaluate these pumps' operational readiness. Therefore, requiring the' licensee to install-more accurate instruments would'present a significant hardship on the licensee with no compensating increase in safety. The licensee's proposal gives adequate i
assurance of operational readiness and provides a-reasonable alternative to -
the Code requirements.
Based on the determination the licensee's proposal;provides a reasonable alternative to the Code requirements and considering the 11.
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, .. 3.3.1.2 Evaluation. These control building chilled water system pumps function to control chiller outlet temperature in conjunction with temperature l control valves, by recirculating a portion of the heat exchanger outlet flow back {
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heat exchanger, upstream of the temperature control- valves. The Code requirements are impractical since there is no instrumentation ~ installed in this L
subsystem to facilitate measurement of differential pressure or flow rate.
This subsystem is 'very difficult to test due to the- changing- system conditions (i.e., service water system pressure, temperature control valve q position, and recirculation flow) and lack of installed instrumentation for establishing repeatable reference conditions and evaluating - the hydraulic condition of these pumps. However, the licensee's proposed-testing does not:
1 provide a reasonable assurance of pump operational readiness since it doestnot l adequately. assess the , hydraulic performance parameters of -these' pumps. 1 Measurement of pump vibration only does'little to aid in evaluating hydraulic '!
performance. Further, heat exchanger flow rate and outlet temperature can be affected by.'a variety of factors unrelated to, or that may effectively mask, changes in pump hydraulic performance. This could prevent the ' detection of.
significant pump hydraulic degradation. Therefore, corrective action may not be called for prior to complete failure of these pumps.
The licensee's proposal does not provide a reasonable long-term;alternat.ive to the Code requirements. A method should be developed to evaluate the hydraulic performance of' these pumps. Temporary installation :f- differential pressure instruments and measurement of flow rate using clamp-on ultrasonic flow detectors
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allow an evaluation of pump- hydraulic condition' to determine pumpvoperational readiness. The . licensee's current testing should give adequate assurance of operational readiness while the licensee develops a' method of' evaluating these pumps.
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- 4. val.VE TESTING PROGRAM !
l The Nine Mile Point, Unit 2, IST program submitted by-the Niagara i
Mohawk power Corporation was examined to verify that all: valves included in I the program are subjected to the periodic tests required by the ASME Code,;
l Section XI,1983 Edition through Summer 1983 Addenda, and NRC positions and l guidelines. The reviewers found that, except as.noted-in Appendix 8 or where specific relief from testing has been requested,'these valves are tested to the Code requirements and the NRC positions and guidelines. Each l
Niagara Mohawk Power Corporation basis for requesting relief from the valve testing requirements and the reviewer's evaluation-of that request is summarized below and grouped according to the system and: valve Category. .
4.1 General Valve Relief Recuests 4.1.1 Containment Isolation Valves 4.1.1.1 Relief Recuest. The licensee has requested relief from exercising the containment isolation valves in accordance with the requirements of Section XI, Paragraphs IWV-3421 through1-3425, and proposed to verify valve ~ leak tight integrity by leak rate ~ testing' these valves in accordance with the requirements of 10 CFR 50,- Appendix J, and complying - . ;
with the requirements'of Paragraphs IWV-3426;and 3427. I i
l 4.1.1.1.1 Licensee's Basis for Reouestina Relief--Containment. ,
isolation valves that must be leakage rate tested in.accordance with !
10 CFR 50, Appendix J have been' identified,as Category A valves for ASME XI i
testing purposes. 'However, excess flow check valves listed as containment isolation valves in the Technical Specifications only receive an l l ~
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. operability test and'do not receive a leak rate test. The leakage rate requirement is based on a total' allowable leakage. rate for'all valves instead of an individual valve leakage-rate. IWV-2200(a) defines l Category A as " valves for which seat leakage is limited to a specified maximum amount in the closed position of fulfillment ~ of thelf function."
Although, leakage rates of containment isolation valves.are not limited on- '
- an individual basis, they have been classified as-Category A valves.
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4.1.2 Excess Flow Check Valves 4.1.2.1 Relief Reaues1 The licensee has requested relief from exercising the excess flow check valves.in accordance with-the requirements <
of Section XI, Paragraph IWV 3522, and proposed to perform _ functional testing on_these valves during refuel hg outages.
4.1.2.1.1 Licensee's Basis for Reauestina Relief--Excess flow check valves are installed on instrument lines penetrating containment to minimize leakage in the event of an instrument line failure outside'the a containment in accordance with Regulatory Guide 1.11. The excess flow l check valve is basically a spring loaded ball check valve. 'Since the I system is normally in a static condition, the valve ball is held open by~ ;
the spring, Any sudden increase in flow thru the valve (i;e. line break)'
will result in a differential pressure across the valve which will. overcome i the spring and close the valve. The valve is designed to allow some: i leakage past the seat in the closed position. This. leakage will-act-to equalize pressurr across the valve in the ' event the excess flow condition s
is corrected, thus allowing the spring to reopen the valve. At NMP2 there
. are excess flow check valves with and without installed position indication. Functional testing of valve closure is accomplished,by venting the instrument side of the valve while the process. side'is under. pressure and observing the position indicator (for those with-installed. position indicators) and by verifying that only a small amount of leakage exists thru the vent.
The testing described above requires-the removal of the associated instrument'or instruments from service. Since these instruments are in use during plant-operation and cold shutdown, removal of any of these !
Instruments from service could cause a spurious signal which could result L in a plant trip, an inadvertent initiation of a safety system, loss of.
decay heat. removal an#or the defeating of safety interlocks. - t
. In addition to the ph.nt- safety concerns, personnel safety concerns-must be considered since lhe process side of many of these-valves is normally high pressure (:500 psig) and/or high temperature-(>200'F) and -
4 highly contaminated reactor coolant. The remainder of the valves process
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accordance with the requirements of Section XI, Paragraphs IWV 3417 and L
-3413, and proposed to assign these valves a maximum limiting stroke time ;
of 2 seconds, upon exceeding 2 seconds these valves will'be considered ' '
( inoperable and corrective action will be taken.
l 4.1.3.1.1 l Licensee's Basis for Reauestina ' Relief--IWV.3417 requires corrective action if the measured . stroke time for a valve -that j normally strokes in 10'see or less varies by 50 percent-from the last measured stroke time.
!WV-3413 allows measurement- to the nearest sec for stroke times of 10 sec or.less.
For rapid actuating power-operated valves, the application of the above criteria could result in requiring; corrective action when the valves are functiont~ng normally.
These valves generally are small' air and solenoid operated valves which because of their size and actuator types, stroke very i quickly. -Operating history on this type of valve indicates that they. 1 generally either operate immediately or fail to operate in a' reasonable length of time.
The intent of the referenced Code sections is to track valve stroke-times. as a means of detecting valve degradation. This type of '
valve does not lend itself to this tracking technique.
i Alternative Testina: A maximum stroke time of 2 sec will be specified '
for each rapid actuating valve.
If the valve strokes in 2 sec or less, it-will be considered accepta' 2 and no corrective action will be required.
If the valve. exceeds 2 sec, it will be considered inoperable and.the appropriate corrective action will be taken.
4.1.3.1.2 Evaluation--NRC Generic letter No. 89 04, Attachment 1,'
Position 6, addresses stroke time measurement for rapid-acting l power- d valves.
The licensee's proposal' appears to'be in accordance with i aff position, e
licensee's proposal regarding stroke time measurements for rapid-ac er., power-operated valves-is in-accordance with the requirements '
of Generic letter No.89-04, relief is granted as requested.
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l perform a functional test on the pair quarterly. This test would be ,
adequate provided that upon evidence of leakage through the valve pair both !
1 valves are declared inoperable and are repaired per'IWV-3523.
. Based on the determination that complying with the Code requirements is impracticable and considering the licensee's proposal, relief should be '
granted provided the licensee performs functional testing of the check j
valve pair quarterly and upon evidence'of. leakage through the pair both valves are declared inoperable and corrective action is taken for both valves in accordance with IWV-3523.
4.2 Diesel Generatina System 4.2.1 Q.tLqgn B Valves 4.2.1.1 Relief Recuest. The licensee has requested relief from stroke time measurement for the starting air' supply valves for the diesel 1
generators, 2EGA*PCV25A, 258, 26A, 268, 2EGA*A0V323Ai 'and '3238, in accordance with the requirements of Section XI, Paragraph IWV-3413, and proposed to evaluate diesel generator start. times to determine valvs-operability.
4.2.1.1.1 Licensee's Basis for Reauestina Relief--These' valves are non-ASME and were supplied as part of the: diesel generator skid. Since they are not ASME components'they were not provided with any position indication, therefore, no means to measure individual valve stroke time.
exists. However, any significant degradation or failure of these valves to operate would be indicated by the failure of the diesel generator to start.
within the associated maximum starting time'specified in the Technical j
i Specifications.
Since there are several other reasons that could attribute:
to.the diesel generator failing to start in the required time, an increase '
in starting time only indicates a-possible degradation or failure of these valves.
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-l Alternative Testino:
i In lieu ofc the individual valve stroke time j testing required by IWV-3413, failure _of the-diesel generator to start within the required time will be evaluated to-determine if the cause of the. -:
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- ' I starting supply headers. :
The vendor _ experienced numerous failures during ' !
testing attributed to frequent cycling or " fluttering" of the disk against the back seat travel stop. Therefore,'the valves'were installed upside down causing the valve disk to remain open during normal system operation.
- If a system condition causing a sudden large pressure' differential (at least 200 psig) across the valve in the reverse direction' occurs, the valve disk will lift and travel to the closed position. Since a catastrophic failure in either air starting header would result in the pressure differential required to close-the valve, the vendor determined installing the valve in this configuration would allow the valve to perform its safety !
function without excessive wear to the valve.
i Based on the above discussion NMPC has determined that cycling these valves to perform ASME XI testing requires simulation of a catastrophic failure of one starting-air header'and could result in accelerated-degradation to the ' valve; therefore, these valves will be tested each refueling outage.
Alternative Testina: !'
The valves will be ' reverse flow tested each refueling outage by simulating a catastrophic- failure of one starting air- i supply header while simultaneously verifying that the subject check valve .
closes. -i Verification will be by visual' observation that the valve closes or indirectly by monitoring that the air start motor functions properly (i.e., Diesel RPM).
4.2.2.1.2 Evaluation--These valves are installed upside down in, 1 the starting air headers with the valve disk in the open position. These -
valves close to perform their safety function. Testing these valves' !
closure capability requires simulating a~1arge rupture.of the starting air supply header, which causes a'significant differential-pressure across~the valve, and results in their closure. The only. practical method of exercising these valves closed is by creating the high differential pressure.
Performing this test subjects these valves to_ a rapid hard closure and could result in damage to the valve or valve. body seating surfaces.
It is impractical to perform this testing quarterly or during _
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4 9 4.3.1.1.2 Evaluatign- These valves ara in the feedwater supply lines to the reactor, it is impractical to shut these valves during operation since this would isolate one train of feedwater and cause a transient which could result in a reactor scram. Testing these valves during cold shutdowns can be perfor=&d, however, this requires de inerting the containment which is burdensome to the licensee in both time and material cost (i.e., nitrogen required for inerting) and is also igractical. The licensee's proposal tu verify the closure of these valves during each cold shutdown when the containment is de inerted and each refueling outage gives adequate assurance of operational readiness and provides a reasonable alternative to the Code requirements.
Based on the determination that complying with the Code requirements is impracticable, the licensee's proposal provides a reasonable alternative to '
the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.
4.4 Nitroaen System 4.4.1 Catecorv A/C Valve 4.4.1.1 Relief Reauest. The licensee has requested relief fn,m verification of reverse flow closare for the TIP mechanism nitrogen ;, urge primary containment isolation valve, 2GSN*V170, in accordance with the test frequency requirements of Section XI, Paragraph IWV-3522, and proposed to verify the closed position of this valve during Appendix J Type C, leak rate i testing during refueling outages.
4.4.1.1.1 Licensee's Basis for Reauestina Relief- The only method available to ver5 reverse flow closure is by valves leak rate testing during Appendix J. Type C, testing at refueling, t
Alternative Testina: Reverse flow closure will be verified during Appendfx J. Type C, testing during refueling outages.
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4.5.1.1.2 Evaluation These valves function to isolate the
! instrument air system from the primary system containment during
, containment isolation. They are not equipped with local or remote position indication. Installation of position indication or other instruments to l show valve position would require system redesign and would be costly and
- burdensome to the licensee. Exercising these valves requires entry into ;
j containment, which is impractical quarterly during power operation or j during cold shutdowns when containment is inerted because of the personnel ,
l safety hazard posed by the oxygen deficient atmosphere. Purging and re inerting containment is costly and could result in delay of plant startup from cold shutdown, which would be burdensome to the licensee, t Exercising those valves during performance of Appendix J Type C, leak rate ,
j testing at each refueling outage should give adequate assurance of j operational readiness and provides a reasonable alternative to the Code requirements.
) Based on the determination that complying with the Code requirements is ,
i impracticable, the licensee's proposal provides a reasonable alternative to
] the Code requirements, and considering the burden on the licensee if the
) Code requirements were imposed, relief should be granted as requested.
i 4.5.1.2 Relief Reauest. The licensee has requested relief from
- verification of the reverse flow closure capability for the following main j steam safety relief, automatic depressurization system (ADS) valves
! accumulator and main steam isolation valves' (MSIVs) accumulator inlet air i check valves in accordance with the requirements of Section XI, Paragraph ,
IWV-3522, and proposed to verify these valves' reverse flow closure capability each cold shutdown when the containment is de inerted and each .
refueling outage:
Valve identification Valve identification 21AS*V421 21AS*V1602 2IAS*V431 21AS*V1603 2IAS*V471 21AS*V1604 2!AS*V526 2IAS*V1605 21AS*V546 21AS*V1606 21AS*V571 2!AS*V1607 2!AS*V581 21AS*V1608 2IAS*V1601 27 I
4.6 Reactor Core Isolation Coolina System 4.6.1 Catecory C Valves 4.6.1.1 Relief Recuest. The licensee has requested relief from quarterly verification of the forward flow capability for the reactor core isolation cooling system pump suction from suppression pool check valve, 21CS*V28, in accordance with the requirements of Section XI. Paragraph '
IWV 3522, and proposed to part stroke exercise this valve open utilizing the pump test line quarterly and verify the full stroke capability by disassembling and inspecting this valve during refueling outages.
4.6.1.1.1 Licensee's Basis for Reauestina Relief Full stroke forward flow exercising of this valve by normal system flow paths would require injecting poor quality suppression pool water into either the reactor vessel or the condensate storage tank (CST) which would result in an undesirable water chemistry condition.
The valve can be exercised by returning flow to the suppression pool via the mini flow line, however, due to the smaller line size of the mini flow, the flow rate that could be obtained would result in only a partial opening of the valve. j Since the only means available to full flow test the valve is to inject water into the reactor vessel the valve will be disassembled and inspected ;
at refueling. ;
i Alternative Testina:
Partial forward flow exercise by recirculating water to the suppression pool via the mini-flow line quarterly. The valve will be disassembled and inspected during refueling.
4.6.1.1.2 Evaluation This valve is the suction check for the reactor core isolation' cooling system from the suppression pool. The only full flow paths are to the CST or to the reactor coolant systemIt(RCS).
is impractical to full stroke exercise this valve open with flow quarterly, during cold shutdown, or during refueling outages since this would result intheinjectionofchemicallyimpurewaterintotheCSTorRCSandcause increased corrosion or other effects which could result in premature failure of system components.
This valve can be verified to part-stroke 29' '
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- 4.7.1.1.1 i Licensee's Basis for Recuestino Relief if the valves fail to reclose after testing, the plant would be placed in a LOCA condition. In addition, a recent study (BWR Owner's Group Evaluation of NUREG 0737, item II.K.3.16, Reduction of Challenges and failures of Relief Valves) recommends that the number of ADS openings be reduced as much as j possible.
' Based on this study and the potential for causing a possible LOCA condition, exercise testing of ADS valves will be delayed to refueling.
Concerning valve stroke timing during exercising, the position indication in the Control Room only indicates ADS Relief Valve pilot
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position; there is no direct means for detecting the actual position of the valve disk. The only way possible to determine the opening of the Relief i
Valve is by acoustic monitoring of the SRV line discharge to the suppression pool.
Measuring the time from the initiation signal for the valve and the acoustic monitoring detection does not provide meaningful data for predicting valve degradation.
Currently Technical Specifications require that 50% of these valves be removed and bench testing every 18 months.
During bench testing valve stroke time is measured.
Alternative Testina: Exercise and fail safe during restart after refueling, ,
Stroke time will be performed on 50% of these valves every 18 months during bench testing.
4.7.1.1.2 Evaluation The ADS valves act both as power operated i valves, in respor.se to a manual or automatic control signal, and as safety relief valves. As a result, these valves should be tested to both the Category 8 and C requirements.
Full stroke exercising these. valves nowterly during power operations is impractical as this greatly increases the risk of creating a small-break loss of coolant accident (LOCA).
NUREG 0626 " Generic Evaluation of Feedwater Transients and Small Loss of-Coolant Accidents in GE Designed Operating Plants and Near Ters t Operating License Applications" and NUREG 0737,Section II.K.3.16
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' Reduction of Challenges and Failures of Relief Valves
- recommend the l
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! Alternative Testina: Reverse flow closure will be verified during l Appendix J, Type C, testing during refueling outages.
I 4.8.1.1.2 Evaluation These valves function to provide l containment isolation for the seal water supply lines to the reactor j coolant recirculation pumps. It is impractical to full stroke exercise 4
these valves quarterly during power operation since this requires stopping i
seal water flow to the pumps and could result in damage to the pumps and !
possibly a reactor shutdown. The only practical method of verifying
'; reverse flow closure of these valves is performance of a leak test which ;
requires the recirculation pumps to be stopped and hookups made to put !
reverse pressure on the valves. This is impractical to perform at cold shutdown since it could delay the return to power operation. Exercising this valve during performance of Appendix J, Type C, leak rate testing at ,
each refueling outage should give adequate assurance of operational readiness and provides a reasonable alternative to-the Code requirements.
Based on the determination that complying with the Code requirements is impractical and the licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted as requested.
4.9 Control Rod Drive Hydraulic System 4.g.1 Cateaory B Valves i
4.g.1.1 Relief Reauest. The licensee has requested relief from exercising, stroke timing, and fail safe testing the control rod drive (CRD) scram valves, 2RDS*A0V126 and A0V127, in accordance with the requirements of Section XI, Paragraph IWV 3412, and proposed to verify operability of these valves during control rod scram testing in accordance with Technical Specifications (IM on rotating basis ea:h 120 days of operation, and all rods prior to exceeding 4M power after refueling or reactorshutdown>l20 days).
4.9.1.1.1 Licensee's Basis for Reauestina Relie_f--Individual valve. testing is not possible without causing a. control rod scram with a resulting change in core reactivity. Quarterly testing of these valves 33
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4.9.2.1.1 Licensee's Basis for Recuestino Relief -Individual y valve testing is not possible without causing a control rod scram with a resulting change in core reactivity. Quarterly testing of these valves {'
t would violate plant technical specifications which govern the methods and '
frequency of reactivity changes. Technical specifications surveillance j
(T.S.4.1.3.2) requires periodic individual control rod scram insertion time l ,
measurements with reactor coolant pressure greater than or equal to 950 '
psig and the control rod drive pumps isolated from the accumulators. Since
! A0Vs 126, 127, and check valve Vll4 must open during a control rod scram, i failure of these valves to operate or degradation in the A0V's cycling times would be indicated by larger insertion time for the control rod.
i Alternative Testino: The control rod scram insertion time testing required by Technical Specification 4.1.3.2 will be performed in lieu of the Section XI testing.
At least 10% of the control rods will be tested on a rotating basis for every 120 days of operation.
All rods will be tested prior to exceeding 40% power after refueling or a reactor shutdown greater than 120 days.
4.9.2.1.2 Evaluation..This valve must operate for rapid insertion (scram) of control rods. It is tested by scram timing the control rods.
The licensee's proposal to test 10% of the CR0s each 120 days of operation, i
and 100% prior to exceeding 40% power after refueling or a reactor shutdown greater than 120 days in accordance with plant Technical Specifications appears to be in accordance with the NRC staff position in NRC GL 89 04, '
Attachment 1, Position 7.
Based on the determination the licensee's proposal is in accordance l
with the requiremente of GL 89 04, Attachment 1, Position 7 relief is granted as requested.
4.10 Standby Liouid control System
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4.10.1 Cateoory A/C Valves 4.10.1.1 kelief Raouest. The licensee has requested relief from verifying the forward flow capability of the standby liquid control (SLS) 35
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Based on the deteroination that complying Oith the Code requirements is j
impractical and the licensee's proposal provides a reasonable alternative j
to the Code requirements, relief should be granted as requested.
4.10.1.2 Relief Recuest. The licensee has requested relief from j
verifying the reverse flow closure capability of the standby liquid control l (SLS) injection containment isolation valve, 2SLS*V10, in accordance with 3
the frequency requirements of Section XI, Paragraph IWV-3522, and proposed i ;
to verify the reverse flow closure capability of this valve each cold l
shutdown when the containment is de-inerted and each refueling outage.
4.10.1.2.1 Licensee's Basis for Raouestina Relief This check valve is located inside the drywell and has full reactor pressure imposed on the seat in the reverse direction during reactor operation. Quarterly testing of this valve in the reverse direction during power operation is by opening the upstream test connection valves 2SLS*V30 and V31 located outside the drywell.
However, if the check valve has f ailed in the open position, opening the test connection valves would result in a discharge of -
water at full reactor pressure and temperature (approximately 1000 psig and 500 degrees F) from the test conr.ection. Therefore, opening the test connection valves poses a safety hazard to operating personnel and a l
possible radiation release to the secondary containment.
l It is not possible to perform the reverse flow closure test using this ;
method during cold shutdowns since the reactor is depressurized; there is no differential pressure across the check valve.
The reverse closure test can be performed by closing valve 2SLS*HCV114 and applying pressure in the reverse direction to the check valve through test connection valves j
2SLS*V36 and V371 however, these valves are located inside the drywell l which is normally inerted with nitrogen at cold shutdown.
Alternative Testina: Reverse flow closure exercising of this valve 1
will be performed at every refueling outage and at cold shutdowns in which the containment is de-inerted.
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i 2SLS*V12 and V14 is to remove the associated SLS pump discharge spool piece.
! In addition, the system line up required to establish a reverse flow condition on these valves requires both SLS loops to be cross-connected with both pumps i discharging to the test tank. This line up would render both pumps inoperable which is not permitted during power operation. )
The testing of these valves in the reverse direction will be performed at a refueling frequency until the first refueling outage when a modification will be performed to add the necessary test connections to permit quarterly testing.
Alternative Testina: Verify reverse flow closure at a refueling frequency )
until the first refueling outage when the system will be modified to permit quarterly testing.
4.10.2.1.2 Evaluation- These check valves are installed at. the
, discharge of the SLS pumps to prevent the diversion of flow from both pumps to j the affected pump suction should either SLS pump discharge relief valve, 2SLS*RV2A or RV2B, fail in the open position. There is no instrumentation currently installed to allow testing these valves to their closed position upon flow reversal either quarterly or during cold shutdown. Testing these valves to the closed position requires removal of a piping spoolpiece.- The licensee has proposed to install the instrumentation necessary to verify the reverse flow -
- closure of these valves so that the required testing can be performed by the end l of the next refueling outage. The licensee's proposal should give adequate I assurance of operational readiness and presents a reasonable alternative to the Code requirements.
Based on the determination that complying with the Code requirements is' impracticable and since the licensee has committed to install the instrumentation necessary to perform the testing as required by the Code, interim relief should be granted as requested until the end on the next scheduled refueling outage.
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Based on the determination that complying with the Code test frequency I
requirements is impracticable, considering the burden on the licensee if f
the Code requirements were imposed, and since the licensees proposal provides a reasonable alternative to the Code requirements, relief shoul-be granted as requested, 4.12 Containment Purae Sueoly System 4.12.1 Cateaory A/C Valves l 4.12.1.1 Relief Reauest. The licensee has requested relief from !
verification of reverse flow closure for the containment purge supply
} l valves, 2 CPS *V50 and V51, in accordance with the frequency requirements of Section XI, Paragraph IWV 3522, and proposed to verify their reverse flow closure ability during Appendix J Type C, testing at refueling outages, l 4.12.1.1.1 Licgnsee's Basis for Reauestina Relief These valves l are located inside the suppression chamber. _The only means to verify the reverse flow of these valves is to apply pressure on the downstream side of the valve via a test connection located inside the ' suppression chamber. )
During normal operation and at cold shutdowns, the suppression chamber is inerted with nitrogen, limiting access to emergency situations only.In addition, high radiation levels during power operations prohibit suppression chamber entry. ,
Alternative Testina:
refueling. Reverse flow closure will be verified at 4.12.1.1.2 Evaluation..Th'ese valves are located inside the suppression chamber and function'to supply air to valves 2 CPS *A0V107 and
- A0V10g, inside containment isolation valves, during containment isolation. They are not equipped with local or remote position indication.
Installation of position indication or other instruments to show valve position would require system. redesign.and would be costly and i burdensome to the licensee.
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APPENDIX A l
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APPENDIX A VALVES TESTED DURING COLD SHUTDOWN The following are Category A, B, and C valves that meet the exercising requirements of the ASME Code,Section XI, and are not full stroke exercised every three months during plant operation. These valves are specifically identified by the owner in accordance with Paragraphs IWV 3412 and 3522 and are full stroke exercised during cold shutdowns and refueling outages. All valves in this Appendix have been evaluated and the reviewer agrees with the licensee that testing these valves during power operation is not practical due to the valve type, location, or system design. These valves should not be full-stroke exercised during power operation. These 4 valves are listed below and grouped according to their Code Category and the system in which they are located.
- 1. REACTOR BUILDING CLOSED LOOP COOLING WATER SYSTEM 1.1 Cateoory A Valves Valves 2CCP*MOV15A, 158, 16A. 168, 17A, 178, 94A, and 948 are the inlet and outlet primary containment isolation valves to recirculation pump coolers and reactor building closed loop cooling water system (CCP) return line block valves. Testing during operation would cause a loss of CCP flow to i the recirculation pump seal coolers, motor bearing coolers, and motor ;
winding coolers. The failure of.any one of these valves to reopen after i stroking would result in a complete loss of cooling to the associated recirculation pump, which could cause extensive damage to the pump.
Furthermore, loss of cooling requires a plant shutdown. ' The operating circuitry of these valves only permits full stroke operation. These valves will be exercised and stroke timed each cold shutdown and refueling outage.
I Valves 2CCP*MOV122, MOV124, MOV265, and MOV273 are the CCP supply and return line primary containment isolation valves to drywell unit coolers. !
The drywell coolers are required during normal plant operation to maintain t
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1 simultaneous leakage occurred past the check valves. The operating
- circuitry of this valve permits only full stroke operation. This valve will be exercised and stroke timed at cold shutdowns and at refueling l
outages.
2.2 Cateoory C Valve Valve 2CSH*V59 is the CSH supply from the CST check valve. To test this valve in the reverse direction requires closing the condensate storage tank supply isolation 2CSH*V37 and venting off the supply header by opening ;
2CSH*V124. With the supply header vented reverse flow verification is then j accomplished by opening condensate flushing valves 2CSH*V30 and V31 and 1
valve 2CSH*V10 the bypass around pump discharge check valve. Performance j of this procedure requires removing the CSH system from operation since the condensate flushing valves are located on the CSH discharge piping and initiation of CSH with these valves open would result in overpressurization of the low pressure condensate transfer system piping . Removal. of the CSH system from operation places the plant in a limiting condition for operation in accordance with the plant Technical Specifications. This valve will be exercised to the closed position each cold shutdown and refueling outage.
- 3. LOW PRESSURE CORE SPRAY SYSTEM 3.1 Cateaory A and AC Valves ,
Valves 2CSL*A0V101 and MOV104 are low pressure core spray (CSL) injection inside and outside containment isolation valves. These valves are reactor pressure boundary valves, they also provide isolation between high and low pressure CSL piping. Valve 2CSL*MOV104 is interlocked to prevent opening when the differential pressure between the' reactor and the low pressure core spray system is greater than 88 psid. Testable check valve 2CSL*A0V101 can be operated either by using system flow thru 2CSL*MOV104 or 5 by using the air test operator when differential pressure across.the valve equhi to zero. During normal plant operations, these conditions cannot be ;
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4.2 Cateaory B Valves Valves 2FWS*MOV21A and 118 are feedwater system flow block valves. l Exercising these valves during normal operation would require a significant reduction in power and stopping one loop of feedwater flow. Isolation of one loop of feedwater would introduce undesirable operational transients and could result in a reactor scram. The operating circuitry of these valves only permit full-stroke operation. These valves will be exercised and stroke timed each cold shutdown and refueling outage, S. REACTOR CORE ISOLATION COOLING SYSTEM 5.1 Cateaorv A Valves Valves 2ICS*A0V156 and *A0V157 are reactor core isolation cooling (ICS) injection line containment isolation valves. These valves are testable check valves capable of being operated either by system flow or by the I installed air test operators. The use of system flow to operate during power operation would require injecting cold water from the condensate storage tank into the reactor vessel. Due to the location of the injection point, water could be carried over in the main steam causing damage to the +
main turbine. In addition, thermal shock would occur in the system piping which could reduce expected component life and reactivity spikes would occur that could cause a plant trip. Since the ICS system is depressurized i
during normal operation a differential pressure exists across the testable check valves. The air test operator is only capable of exercising the l valve with zero pressure differential. Part-stroking requires the same l conditions as full stroke testing. Forward flow operability and reverse flow closure will be verified using the air test operators when the l differential pressure.across the valve is zero. These valves will be full-stroke exercised open and closed each cold shutdown and refueling l
l outage.
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i . . I These valves control the flow of hydraulic fluid to the reactor coolant recirculation flow control valves, and their positions control the )
positions of the flow control valves. Exercising these valves during j reactor coolant recirculation flow would cause disturbance of normal loop flow and could result in adverse plant operation, e.g., change $ in l reactivity, power transient, and a possible reactor scram. The operating ;
circuitry of these valves permits only full-stroke operation. These valves will be exercised, stroke timed, and fail-safe tested each cold shutdown and refueling outage.
7.2 Cateaory B Valves Valves 2RCS*MOV18A and MOVl8B are reactor recirculation pump discharge ,
isolation valves. Exercising these valves during normal operation would
, require a significant reduction in power and stopping flow in one i l recirculation loop. Isolation of one recirculation loop would introduce an undesirable operational transient that could result in a reacter scram.
The operating circuitry of these valves permits only full-stroke operation. These valves will be exercised and stroke timed each cold shutdown and refueling outage.
- 8. CONTROL ROD DRIVE ~HYORAULIC SYSTEM 8.1 Cateaory C Valves Valves 2RDS*Vil5 (all 185 HCU's) are the scram accumulator charging and drive water line check valves. Verification of reverse flow closure
! requires securing the CR0 pumps, depressurizing the header, and monitoring the individual accumulator pressure and alarm to verify the valves have closed on reverse flow. This would violate plant Technical Specifications i and could result in a plant scram if performed during power operation. -
Verification of reverse flow closure will be performed by depressurizing
. the header and monitoring the individual accumulator pressures and alarms i to verify the valves have closed on reverse flow. These valves will be
- exercised each cold shutdown and refueling outage.
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I ' exercised and stroke timed each cold shutdown and refueling outage. The above listed A0Vs will be full-stroke exercised ohen and closed each cold shutdown and refueling outage.
9.3 Cateoory C Valve l Valve 2RHS*V143 is the RHS system reactor vessel head spray line check
! valve. To verify forward flow operability of this valve would require the y flow of water from the RHS to ICS through valve 2RHS*MOV104. Due to an H
! interlock on 2RHS*MOV104, which is not psrmitted to be defeated by Technical Specifications, testing can be accomplished only at cold
! shutdown, Part-stroking would require the same operation conditions as l full stroke exercising. This valve will be full stroke exercised open each i l cold shutdown and refueling outage.
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- 10. SERVICE WATER SYSTEM t
- 10.1 Cateoory B Valves i
l Valves 2SWP*MOV3A, 3B, 19A, and 198 are the safety-related service water
! (SWP) to non safety related SWP isolation valves. The closing of 2SWP*MOVl9A or 198 with the subsequent failure of either valve to reopen +
l would result in a complete loss of cooling to CCP heat exchangers. This ,
- loss of cooling would result in loss of cooling to the reactor recirculation pumps and to the drywell cooling system. The closing of 25WP*MOV3A or 3B with subsequent failure of either valve to reopen would result in a complete loss of cooling to the turbine building closed cooling I water (CCS) heat exchangers which cool the turbine generator. This loss of I cooling water would require tripping the turbine generator and a subsequent
! power transient that could result in a reactor trip. The operation
! circuitry of these valves permits only' full-stroke operation. These valves ,
i will be exercised and stroke timed each cold shutdown and refueling outage.
i j Valves 2SWP*MOV50A and 508 are the SWP header cross connect valves. Both- ,
CCP and CCS are supplied from the A SWP division. Since they are the largest SWP loads during normal plant operation, a large load imbalance A-11>
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a lengthy heat up procedure to prevent thermal shocking of system piping and components. In addition, performing of this heat up procedure requir9s '
local temperature to be taken on the WCS piping, since this piping contains I reactor coolant high personnel exposure rates would result. Finally, 2WCS*MOV102 is located inside the primary containment which is inaccessible during power due to high radiation levels and the inerted atmosphere, failure in the closed position would result in a complete loss of WCS. The .
operating circuitry of these valves permits only full-stroke operation, i These valves will be exercised and stroke timed each cold shutdown and refueling outage.
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i APPENDIX B IST PROGRAM ANOMALIES IDENTIFIED DURING THE REVIEll t
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IST PROGRAM ANOMALIES FOUND OURING THE REVIEW !
Inconsistencies and omissions in the licensee's program noted during the course of this review are summarized below. The licensee should resolve these l
items in accordance with the evaluations, conclusions, and guidelines presented l in this report.
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- 1. Pump relief request GPRR 1 (see Section 3.1.1 of this report) requests i relief from measurement of vibration displacement per IWP 4500 and proposes to measure vibration velocity as described in their IST program, which is similar to the program in OM 6. Relief should be granted provided the
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licensee utilizes all the criteria regarding vibration testing contained ;
in ASME/ ANSI OMa 1988 Part 6.
- 2. Pump relief request SWP PRR-1 (see Section 3.3.1 of this report) requests.
relief from measuring pump inlet pressure, differential pressure, and flow rate for the control building chilled water pumps, 25WP*P2A and B, per I Paragraph IWP-3100, and proposed to measure pump vibration in units of '
velocity and monitor system temperatures and flow quarterly. The licensee's proposed testing does not adequately monitor pump hydraulic >
condition nor does it permit detection of hydraulic degradation. A method should be developed to evaluate the hydraulic performance of these pumps within one year or until the next refueling outage, whichever is longer. '
- 3. Valve relief request GVRR-4 (see Section 4.1.4.1 of this report) requests i to test the keep fill system check valves, 2CSH*V17, V55, 2CSL*V14, and !
l V21, as a unit qsrterly, however, the licensee has not specified that corrective action will i>s taken if the pair fails to prevent backleakage.
Relief should be granted, provided that upon evidence of leakage through !
the pair, both valves are declared inoperable and corrective actions are performed in accordance with IWV-3523.
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4, The licensee has proposed in their cold shutdown justification to defer testing the ICS inboard primary containment isolation valve, 2iCS*MOV128, untti cold shutdown. Though failure of this valve, which is located inside containment and inaccessible during power operation, in the closed position during normal operation would render the ICS system inoperable it does not justify this extended test interval. This valve should be exercised and stroke timed quarterly.
- 5. The licensee has requested relief from quarterly verification of the forward flow capability for the reactor core isolation cooling system pump suction from suppression pool check valve 21CS*V28, in accordance with the requirements of Section XI, Paragraph IWV 3522, and proposed to verify its full stroke capability by disassembling and inspection during refueling outages (see Section 4.6.1.1 of this report).
- An acceptable method for verifying the full stroke open capability of a check valve is disassembly and inspection. However, the NRC staff I
considers valve disassembly and inspection to be a maintenance procedure 1 with inherent risks, which make its use as a substitute for testing l undesirable when testing methods are possible. A preferred alternative is to verify that the valve moves to its fully open position by use of l non intrusive diagnostic testing techniques during a reduced flow test at l
1 east once each refueling outage. The licensee should actively pursue the use of non intrusive diagnostic techniques to demonstrate that this valve swings fully open during partial flow testing. If another method is developed to verify the full stroke capability of this va' i, this relief request should be revised or withdrawn. '
- 6. The licensee has requested temporary relief (see Section'4.10.2.1 of this j
report) from verifying the reverse flow capability of .the SLS pumps discharge check valves, 2SLS*V12 and V14, in accordance with the
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requirements of Section XI, Paragraph IWV-3522, and proposed to verify ;
reverse flow closure capability of these valves during refueling !
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- . .. o outages and to modify the system to permit performance of this test quarterly. Since the licensee has comitted to install the instrumentation necessary to perform the testing as required by the Code, interim relief should be granted as requested until ,the end on the next. scheduled refueling outage.
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