ML20082P829
ML20082P829 | |
Person / Time | |
---|---|
Site: | Summer ![]() |
Issue date: | 06/30/1991 |
From: | Hartley R EG&G IDAHO, INC., IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY |
To: | NRC |
Shared Package | |
ML20079K296 | List: |
References | |
CON-FIN-A-6812 EGG-NTA-7424, EGG-NTA-7424-R02, EGG-NTA-7424-R2, TAC-49976, NUDOCS 9109110096 | |
Download: ML20082P829 (50) | |
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Enclosure 2 EGG NfA 7424 Revision 2 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM VIRGIL C. SUMMER NUCLEAR STATION Docket No. $0-395 R. S. Hartley Published June 1991 Idaho National Engineering Laboratory EG&G Idaho, Inc.
Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory-Comission Washington, D.C. -20555 Under DOE Contract No. DE-AC07 761001570 FIN No. AG812 TAC No. 49976 Q\ R A \.L SO ('(' MA \lh\
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ABSTRACT This report presents our evaluation of the Virgil C. Summer Nuclear Station inservice testing program for safety-rela'od pumps and valves.
PREFACE This 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.
FIN No. A6Cl2 B&R No. 920 19 05-02-0 Docket No. 50 395 TAC No. 49976 11
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CONTENTS ABSTRACT .............................................................. ii PREFACE ..... .......................................... .............. ii
- 1. INTRQDUCTION ................................................ ..., 1
- 2. PUMP TESTING PROGRAM ............................................. 3 2.1 Diesel Generator Fuel Oil Transfer Pumos ................... 3 2.1.1 Inlet Pressure Differential Pressure, Bearing Temperature, and Allowable Ranges of Reference
< Values.............................................. 3 2.2 Service Water Pumps ........................................ 5 2.2.1 Bearing Temperature and Vibration Measurements ..... 5 2.2.2 Flow and Differential Pressure Measurements ........ 6 2.2.3 Re f er ence Val ue Range s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Boric Acid Transfer Pump 5 .................................. 10 2.3.1 flow Measuremuut, Bearing Temperature Measurement, and Observation of Lubricant level.......... ...... 10 2.4 Charging Pumps ........ .................................... 12 2.4.1 Quarterly flow Heasurement ......................... 12 2.5 Chilled Water Pumps ........................................ 14 2.5.1 flow and Otfferential Pressure Measurement ......... 14 2.6 Temperature Instrumentation ................................ 15 2.6.1 Full-Scale Range ................................... 15
- 3. VALVE TESTING PR0 GRAM ............................................ 17 3.1 All Systems ................................................ 17 3.1.1 Rapid Acting Valves ................................ 17 3.2 Component Cooling Water System ............................. 18 3.2.1 Category C Valves .................................. 18 3.3 Chemical and Volume Control System ......................... 19 3.3.1 Category C Valves .................................. 19 111
3.4 Emergency feedwater System ................................. 20 3.4.1 Category C Valves .................................. 20 3.5 Safety Injection System .................................... 23 3.5.1 Category A/C Valves ................................ 23 3.5.2 Category B Valves ................................. 27 3.5.3 Category C Valves .................................. 28 3.6 Reactor Building Spray System .............................. 29 3.6.1 Category A/C Valves ................................ 29 ,
3.6.2 Category C Valves .................................. 31 ,
APPENDIX A P&lD LIST ,.................................. ............. A1 APPENDIX 8 15l PROGRAM AN0P:'.lE$ 10ENTiflED IN THE REVIEW . . . . . . . . . . . . B1 iv _ _ - . . . _ . . . _ _ _ . . . _ _ . . _ _ _ _ . _
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- t TECHNICAL EVALUATION RE20RT !
t gtMP AND VALVE INSERVICE TESTING PROGRAM VIRGYL C. SUMMER NUCLEAR STATION l 1 INTRODUCTION Contained herein is a technical evaluation of the pump and j
- valve inservice testing (IST) program submitted by the South Carolina Electric and Gas Company (SCE&GC) for its Virgil C. Super
~ Nuclear Station. j By a letter dated December 23, 1987, SCEECC submitted an IST program for the Virgil C. Summer Nuclear Station. A working j meeting _was held with SCE&GC and V. C. Summer representatives-on '
June 1, 1988. The first ten-year IST interval Wtarted on Janua:ty I', 1984 and ends January 1, 1994. The IST prograr eavision 3 for j pumps, as attached to c letter to NRC,_ dated August 31, 1988, was '
reviewed- to- verify compliance of the proposed _ tests for I
-safety-related pumps with the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Prs aure vessel Code (the ,
Code), Section' XI,1980 Edition through Winter 1980 Addenda,10 CFR l 50.55a, and NRC positions and guidelines. The proposed tasts of safety-related valves, Revision 4, as attached to a letter to NRC, dated July 19, 1989, was reviewed to verify compliance _with the- -l Code,Section XI, 1977 Edition through Summer 1978 Addenda,10 CFR 50.55a, and HRC positions and guidelines.- Future program revisions should-follow the guidance of Generic Letter No. 89-04 (GL 89-04) ,
"Guidanco on Developing Acceptable Inservice Testing Programs."
In their submittal, SCE&GC requests relief from certain ASME Code testing requirements for specific pumps and valves. These-requests were - evaluated using the .Oraft Regulatory Guide and ;
Value/ Impact Statement titled " Identification of Valves for
-Inclusion in Inservice Testing Programs," and GL 89-04, the acceptance criteria of the Standard Review Plan, Section 3.9.6, and other-references as applicable.
Section 1 of this report identifies the licensee's IST program j I
and the. review method.
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Section 2 of this report presents the SCE&GC bases for '
requesting relief from the Section XI requirements for pumps and gives EGLG's sytluations and conclusions. Section 3 presents sinilar-inrormation.for valves.
Appendix A lists piping and instrumentation diagrams (P& ids) used for this review.
Ar, endix B lists program inconsistencies and omissions and
'.'entifies needed program changes.
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- 2. PUMP TESTING PROGRAM
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-The.following SCE&GC pump relief. requests _were evaluated against the !
requirementst of the :ASME Code,Section XI,10 CFR_50.55a and applicable NRC 1 a
- positions:and guidelines. A summary and the licensee's. basis for each reliefJrequest is presented. The reviewer's evaluation and recommendation follow. ;The requests are grouped according to tocle or system. {
2.1 Diesel Generator Fuel Oil Transfer Pumos 2.1,1 Inlet Pressure. Differential Pressure. Bearino Temoerature, and x Gllowable Ranoes of Reference-Values ,
2.1.1.l'! Relief Reauest. The licensee has requested relief from the 4 requirements of Section_XI, Paragraph IWP-3100, to measure bearing temperaturr. inlet press're, u and differential pressure on the diesel-generate f el J oil transfer pumps, XPP-4A, -48, -141A, and -1418, and proposed' to measure pump flow rate and vibration _once per month and to 4
assign administrative: limits for pump flow rate. :
2.1.1.1.1 Licensee's Basis for Reouestino Relief--These pumps are N itive displacement.(rotary screw) with inaccessible, self lubricated in ernal bearings. Flow and vibration are indicative of pump nerformance, achnical Specifications require 5 gpm minimum flow rate from each pump for-
-diesel operation. Measured flow ratenfor each of these pumps is approximately 42 gpm,140% above minimum re'uired-for diesel operation.
4 However.1the level instruments 1in the day tank used in the flow calculaticas can-experience a 2% acceptable deviation. This deviation amount may provide results on the low flow rate pumps which are outside the Code requirements, bet within the diesel safety function acceptance criteria.
- ligrnate Test: Flow rate measurement ano vibration measurement will be z
,erformed during normal diesel testing, one/ month. Establish an administrative minimum limit af'9 gpm, which is 80% ~above minimum required .
for_ diesel operation. For flow rates between 5 and 9 gpm, evaluate pump safety _ function performance before returning to service. Declare pump inoperable at $5 gpm flow rate.
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2.1.1.1.2 Evaluation -These are positive displacement pumps in '
i the diesel generator fuel oil transfer system. Changes in pump inlet pressure have no effect on flow rate or discharge pressure provided net positive suction head requirements are satisfied. Calculating or measuring inlet pressure would not contribute meaningful data for monitoring pump degradation. The hardship of the calculation or installation of instruments would not be offset by a compensating increase in safety. '
1 These pumps discharge into a vented tank. The discharge line has no control valves for varying pump discharge pressure. The discharge pressure is essentially the pressure of the head of oil above the tank inlet. The discharge pressure is low and does not change significantly during the I test. Normally, differential (or discharge) pressure and flow rate are evaluated together to assess pump hydraulic condition. In this case, the discharge pressure is low and essentially constant and is not a significant performance indicator. Performing calculations or redesigning the system to allow control and direct measurement of discharge pressure (or differential pressure) would be a hardship that would not be offset by a corresponding increase in safety.
Instrumentation for measuring flow rate is not installed. But, flow rate can be calculated by monitoring the rate-of-change of level in the diesel generator day tank during pump testing with the diesel stopped. A calculated flow rate is an acceptable alternate method provided the calculation accuracy is at least that required by Table IWP-4110-1-for the corresponding measured parameter ( 2%). If flow rate can be calculated accurately, the hardship of installing an instrument would not be offset by and increase in quality and safety since it would not considerably improve the ability to detect pump hydraulic degradation.
The proposed corrective action acceptance criteria are unacceptable.
The Code requirement to esthblish reference values for pump testing provides a mechanism to track pump hydraulic parameters to monitor pump degradation and assure operational readiness. The licensee's method would allow the pump to degrade to less than one half normal capacity before requiring corrective action. Allowing hydraulic degradation of the magnitude proposed in this relief request before corrective action is taken is 4
e f ar beyond that allowed by Table IWP '4100-2. Pump failure would likely occur before the flow rate drops to the proposed required action limit, therefore, relief should not be granted to use these limits.
The proposal to calculate pump flow rate (if calculated as discussed) and measure vibration-during pump tests should provide sufficient information to assess the mechanical and hydraulic condition of these positive displacement pumps and provides an acceptable alternative te the Code requirements.
Based on the determination that requiring compliance with the Code
, requirements to measure inlet pressure, differential pressure, and bearing temperature would be a hardship on the licensee without a compensating increase in the level of safety, relief should be granted from these requirements provided the calculated flow rate meets the accuracy requirements of Table IWP 4110-1. Relief should not ta granted to use the proposed acceptance criteria, the licensee should establish flow rate reference values and use the accept.ance criteria of Section XI, Table IWP-3100-2.
2.2 Service Water Pumos 2.2.1 Bearina Temoerature and Vibration Measurements 2.2.1.1 Relief Recuest. The licensee has requested relief from the requirements of Section XI, Paragraph IWP 3100, to measure bearing temperature and vibration on the service water pumos, XPP-0039A, -0039B, and
-0039C, and proposed to measure vibration at the motor bearings and to measure the temperature of the pumped fluid in lieu of the bearing temperature.
2.2.1.1.1 Li_qensee's Basis for Reouestina Relief--These pumps are vertical pumps with the pumping units housed in a column below the floor structure of the service water pump house. The bearings are inaccessible for measurement of vibration and temperature.
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4 Alternate Test:
Vibration measurements will be taken on the motor inboard -
and outboard bearings. The fluid temperature of the-water being pumped will be measured.
2.2.1.1.2 Eyjtluation -These service water pumps are vertical line shaft type with the pump submerged in the pumped fluid. Instrumentation is not installed to allow bearing vibration or temperature measurements on the pump body. Also, since these pumps are submerged and inaccessible, portable instrumentation :annot be used during testing. Therefore, taking these measurements is impractical. Measuring vibration at the inboard and outboard motor bearing can indicate pump degradation. This provides a reasonable alternative to the Code. System redesign would be necessary to allow measurement of pump bearing vibration and would be costly and burdensome to the licensee.
The licensee's proposal to measure the temperature of the pumped service water is unnecessary because Section XI, Paragraph IWP-4310, requires temperature measurements of those centrifugal pump bearings located outside the main flow path. The bearings of these service water pumps are located in the flow path and cooled and lubricated by the pumped fluid. It is doubtful that service water temperature measurements would provide any meaningful indication of bearing condition due to the volumc of water passing the bearing and the seasonal variations of the water temperature.
Based on the determination that compliance with the Code requirements is impracticable and considering the burden on the licensee if the Code requirements were imposed and the licensee's proposal, relief should be granted 'from the bearing temperature and specified vibration measurement location requirements of Section XI as requested.
2.2.2 Flow and Differential Pressure Measurements 2.2.2.1 Relief Recuest. The licensee has requested relief from the requirements of Section XI, Paragraph IWP-3100, to establish fixed reference W
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values for flow and differential pressure on service water pumps, XPP 0039A,
-0039B, and -0039C, and proposed to use pump curves to compare flow and differential oressure.
2.2.2.1.1 Licensee's_Basit for Recuestino Relief--The service water system provides raw cooling water to many safety-related systems and essential equipment. Adjusting flow or differential pressure to a single point reference value would interrupt service water flow rate to much of this equipment, thus providing a potential for system safety function degradation.
Alternate Test: Use individual insitu pump test curves by plotting minimum and maximum differential pressure alert and required action ranges on each test curve. Recor- fica and verify differential pressure results within acceptance limits of pump test curve.
2.2.2.1.2 Evaluation--These service water pumps operate under a variety of flow rate and differential pressure conditions. These conditians result from multiple independent changes (cycling of flow control valves) in system cooling demand, which make it impractical to return to a reference value. Significant system redesign and modification is needed to facilitate returning to fixed points of operation for testing. This would be very costly and burdensome to the licensee. The licensee has proposed to use insitu pump curves to determine acte,ptance criteria for inservice tests.
Measurements will be taken in the "as found" condition of pump flow and differential pressure in lieu of returning to fixed reference values.
Using a reference pump curve to compare differential pressure and flow rate for pump inservice testing can provide an acceptable alternative to the Code. A reference pump curve describes an infinite number of fixed sets of reference values for pump flow rate and head. However, it is important that the insitu reference curve is developed, or the manufacturers curve is validated, when the pump is known to be operating acceptably and that it is based on, or validated by, an adequate number of measurement points.
Further, acceptance criteria based on the pump curve should not conflict with Technical Specification or Facility Safety Analysis Report operability 7
4 criteria for flow rate and differential pressure. Additionally, since the ,
levels of vibration may vary significantly over the range of pump conditions encountered during testing, the licensee should develop a method for:
assigning vibration acceptance criteria that will give equivalent protection as provided by the Code. This may require taking vibration measurements at various points on tha pump curve and assigning conservative vibration velocity reference values for regions of the pump curve. The pump curve may be divided into as many_ regions as necessary.
Based on the determination that compliance with the Code requirements is impractical, the burden on the licensee if the Code requirements are imposed, and considering the licensee's proposal, relief should be granted from the Code requirements provided the insitu pump curves are developed or manufacturers curves are validated when the pump is known to be operating
&cceptably, at described above, and the method of assigning acceptance criteria for vibration measurements _ yields equivalent protection as provided by the Code.
2.2.3 Reference Value Ranaes 2,2.3.1 Relief Reauest. The licensee has requested relief from the allowable range requirements of Section XI Paragraph IWP-3210 and Table IWP-3100-2, for flow and differential pressure measurements on service water pumps XPP-0039A, -00398, and -0039C, and proposed to establish expanded ranges for these parameters to accommodate additive instrument errors.
2.2.3.1.1 Licensee's Basis for Reouestinn Relief--When testing these centrifugal pumps, minute increases in differential pressure and flow are not significant. However, acceptable instrument / transmitter error (12%
full range), total instrument range (13 times the reference value), water density, and/or personnel visual acuity could be the cause for recording differential pressure and flow values which fall outside the acceptable range.
Recognition of the present " alert range" requires the affected pump be subjected to an increased frequency of testing. This increased test 8
l frequency lends the pump to additional unavailability while unneces n ry pump cycling may, in fact, reduce pump reliability.
The present " required action range" specifies that the pump be declared inoperable until corrective action has been taken. Corrective action can take the form of replacement, repair, or analysis to demonstrate operability and function, tgain, minute increases due to acceptable instrument error and range, water density, etc., can lead to additional testing, replacement, repair, or analysis activities. These activities can further reduce pump availability and reliability. (Reference Relief Request E.2, Attachment 1, for instrument error details. The licensee has provided three pages of examples and calculations, which show an additive instrument error of 9.8.
for service water pump differential pressure calculated from flow measurements taken at four different locations with four different instruments.)
Alternate Test: To provide a method to diagnose and correct significant and meaningful problems, yet permit a sufficient range to prevent unnecessary testing and unavailability, specify the high " alert range" and high
" required action range" for flow and differential pressure to be consistent with OH 6,
- 1. Alert Range - 1.08 to 1.10r*
.2. Required Action Range -->l.10r a
- r is the reference value 2.2.3.1.2 Evaluation--The licensee has provided examples (Relief Request E.2, Attachment 1) that show that summing the output of four different flow instruments could result in flow rate values whose accuracy could greatly exceed the allowable ranges of Table IWP-3100-2. However, the licensee has not provided a technical basis that shows the proposed acceptance criteria will give adequate assurance of pump operational readiness when applied to their pump test parameter values as part of Section XI testing. The Section XI limits are more restrictive on the high side than the licensee's proposal. This, in-effect, limits the amount of 9
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deviationiininstrument=accuracysinceitisunlikelythatpumphydraulic performance wculd increase. The prooosed expanded high side-limits would greatly increase the range of-test ameter -ilues that would be acceptable- ,
and could act'to-allow continued operation of a pump that is severely !
Aegraded, ~Therefore, the_l_icensee's proposal does not provide a reasonable alternative to the Code requirements.
Service-water system piping and instrumentation diagram (P&lD),
D 302 221,. RIS . dated 3/13/89, which was_provided after the program -
submittal, shows a- flow element with an indicator installed in each sarvice water header. TheseLelements, FI-4586 (A loop)'and FI 4587 (B loop),:are arranged such that each he e can be solated, or solit if operated in parallel, and individual pt. . flow ra- can be obtared. If these flow rate instruments meet the accuracy reqLirements of Tasle IWP 4110 1, the test data should be sufficiently accurate to use the Code specified acceptance criteria.
Also,- better results can be-achieved by repeating from one-test to the next the conditions under which the tests are conducted. To the extent practical the same instruments, procedures, personnel, location, operating conditions, etc. should be maintained ~ for a given test. When repeatability cannot be maintained, appropriate compensatory measures should be taken.
Since the 1icensee has not shc . hat using the-C speci-acceptance criteria is-impractical or ; hat it imposes xcess 1ardship without'a compensating increase in safety, and since -
- licensee s proposed alternative does not provide a reasonable alternative to the Code '
requirements, relief should not be granted as requested.
2.3 Boric Acid Transfer Pumos 2.3.1 -Flow Measurement. Bearino Temoerature Measurement. and Observation of Lubricant level 2 . 1 Relief Reouest. The li see has requested relief from the requirements of Section XI, Paragraph dP-3100, to measure flow, bearing temperature, and to observe lubricant level on the boric acid transfer r
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Q pumps, XPP 13A and -138, quarterly and proposed to measure flow rate and fluid temperature during each cold shutdown.
2.3.1.1.1 Licensee's Basis for Reauestina Relief- The boric acid tanks are normally kept at 90*.' capacity. The remaining 10% is insufficient volume to conduct the flow rate tes due to the incremental sensitivity of the level instrumentation which is used to measure flow rato.
The bearings are sulf lubricated and are inaccessible for temperature measurement. The lubricant is the pumped fluid and cannot be directly visually observed. Normal flow rate indicates lubricant level is satisfactory.
Alternate Tell: Initiate flow rate test within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of attaining Mode 5 (cold shutdown) at which time boric acid tank fluid levels car, be adjdsted to provide the space needed to contain the large volune of test water. The pumped fluid temperature will be measured.
2.3.1.1.2 fyalu_a_tJiu--Quarterly flow rate measurements cannot be taken on the boric acid transfer pumps because the recirculation line is not equipped with flow instrumentation though one pump is normally in operation tu recirculate the boric acid storage tanks. The recirculation line must be used during the quarterly tests as the only other flow path is into the charging pumps' suction and into the reactor coolant syster (RCS).
Establishing flow through this path for testing could result in a reactor shutdown. The proposal to measure flow during cold shutdowns is a reasonable alternative to the quarterly flow measurements required by the Code because more accurate information can be obtained when the G . tem can be realigned for testing. Compliance with the Code requirements is impractical due to the lack of installed instrumentation in the pump recirculation line. It would be burdensome for the licensee to perform a system modification to allow quarterly testing.
The licensee's proposal to measure the temperature of the solution pumped is unnecessary because Section XI, Paragraph IWP-4310, requires 11
temperature measurements of those centrifugal pump bearings located outside the main flow path. The bearings of these boric acid transfer pumps are in the flow path and cooled and lubricated by the pumped solution. It is doubtful _that boric acid solution temperature measurements would provide any meaningful indication of bearing condition due to the volume of solution passing the bearing and normal variations in solution temperature.
Based on the impracticality of complying with this Code requirement And the burden on the licensee if this Code requirement is imposed, relief should be granted from the Section XI requirement to measure f1w quarterly, as requested.
2.4 Charoino Pumos 2.4.1 Quarter 1v Flow Measurement 2.4.1.1 Relief Recuest. The licensee has requested relief from the requirement of Section XI, Paragraph IWP-3100, to measure flow rate of the charging pumps, XPP-43A, -438, and -43C, quarterly and proposed to measure flew during refueling outages.
2.4.1.1,1 Licensee's Basis for Reauestino Relief--During normal operation and cold shutdown, partial flow testing would require three separate groups of flow elements to be considered. These are the charging, seal injection, and letdown flow elements. Combined instrument inaccuracy could be 12%. Full flow testing duriag normal operation would thermally shock the safety injection (SI) nozzles. Full flow testing during cold shutdown would require initiating flow into the RCS. The volume available in the pressurizer would provide only six to seven minutes to record all readings. This is not enough time to record all ISI required readings. In addition, the lack of volume in the pressurizer during cold shutdown may cause cold temperature overpressurization of the RCS.
Alternate Test: Perform all required tests through the miniflow recirculation line once each quarter, except flow. Perform all tests, 12 u
, including flow, each refueling outage when the reactor vessel head is removed and the refueling cavity can be used to contain the large volume of water required for flow ter. ting.
2.4.1.1.2 Evaluation -The charging pumps provide flow thru several paths during power operation. Pump flow rate can be determined by combining separate flow rate instrument readings, which are cach inaccurate to some degree. The licensee has stated the combined instrument inaccuracy could be as great as 12%, but has not shown the basis for this determination, it is not practical to isolate any of these flow paths to obtain more accurate flow rate data since it could result in damage to vital plant equipment, such as the reactor coolant pumps if seal water flow is isolated. Charging pump flow rate measurements can be made quarterly and are essential for determining pump hydraulic condition. The proposal to perform quarterly testing through the miniflow line without measuring flow rate and to measure flow rate during refueling outage testing does not give adequate assurance of operational readiness and does not provide a reasonable -alternative to the Code requirements.
The NRC is authorized by law to grant relief from the Code requirements when the licensee demonstrates either that their proposed alternatives would provide an acceptable level of quality and safety, that compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety, or that the Code requirements are impractical. The proposed alternative has not been shown to provide an acceptable level of quality and safety. The licensee has not provided information on the hardship that results from measuring pump flow rate and has not demonstrated that there would be no compensating increase in safety.
And lastly, whereas it may be inconvenient to measure flow at the Code required frequency, it has not been shown to be impractical. Therefore, relief should not be granted from the Code requirements.
The licensee should continue to measure pump flow rate quarterly. The licensee should also perform the flow test during refueling outages when flow can be directed to the RCS. Instruments used should meet the Code i
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.' i accuracy requirements. if the Code flow rate instrument accuracy or-acceptance criteria.requirementr cannot be met during quarterly testing .the' ;
= licensee'should request relief and justify their proposed alternates. -The ,
- licensee should specifically address the instrumen'. and total: loop accuracies ~and show the proposed testing will give adequate assu'rance of-pump operational readiness _ and provido a reasonable alternative to the Code -
requirements.
2.5 Chilled Water Pumns 1
2.5.1 Flow and Differential pressure Measurements 2.5 l.1 Relief Reauest. The licensee has requested relief from the requirements.of Section XI, Paragraph IWP-3100, to establish fixed reference values for flow and differential pressure on chilled water pumps, XPP-0048A,
-00488, Land -0048r, and proposed to use pump curves to compare flow and '
di f ferential - pressure.
2.5.1.1.1 Licensee's_Easis for Reauestino Relief--The chilled 3 water _ system provides cooling water to-other safety related systems and L essential equipment. Adjusting flow or differential pressure to a single ,
point reference value would interrupt chilled water flow rate to much of this equipment, thus providing potential for system safety function degradation.-
Alternate: Test: Use individual insitu pur test curves by plotting minimum
- and maximum ' differential pressure alert aru required action ranges on each test curve. Record flow and verify differential pressure results within acceptance limits of pump test curve.
2.5.1.1.2 Evaluation--These chilled water pumps operate under a variety of flow rate- and-differential pressure conditions. These conditions are dictated.by_ cooling demand and make it impractical to return to a reference value. Significant system redesign and modifications are needed to facilitate returning to fixed points'of operation for testing. This
-would be very costly and burdensome to the licensee. The licensee has proposed to use insitu pump curves to determine acceptance criteria for 14
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l inservice testing with measurements taken in the "as found" condition of pump flow and differential pressure in lieu of returning to fixed reference values.
Using a reference pump curve to compare differential pressure and flow rate for pump inservice testing can provide an acceptable alternative to the Code, A reference pump curve describes an infinite number of fixed sets of reference values for pump flow rate and head. However, it is important that the insitu reference curve is developed, or the manufacturers curve is validated, when the pump is known to be operating acceptably and that it is based on, or validated by, an adequate number of measurement points.
Further, acceptance criteria based on pump curves should not conflict with Technical Specification or Facility Safety Analysis Report operability criteric for flow rate and differential pressure. Additionally, since the levels of vibration may vary significantly over the range of pump conditions encountered, the licensee should develop a method for assigning vibration acceptance criteria that will give equivalent protection as provided by the Code. This may require taking vibration measurements at various points on the pump curve and assigning conservative vibration velocity reference values for regions of the pump curve. The pump curve may be divided into as many regions as necessary, Eased on the determination that compliance with the Code requirements is impractical, the burden on the licensee if the Code requirements are imposed, and considering the licensee's proposal, relief should be granted from the Code requirements provided the insitu pump curves are developed or manufacturers curves are validated when the pump is known to be operating acceptably, as described above, and acceptance criteria for vibration measurements give equivalent protection as provided by the Code.
2.6 Temoerature Instrumentation 2.6.1 Full-Scale Ranae 2.6.1.1 Relief Reouest. The licensee has requested relief from the full-scale range requirements of Section XI, Paragraph IWP-4120, for 15
. e j portable temperature instruments and proposed to'use digital temperature instruments.
2.6.1.1.1 Licensee's Basis for Reauestina Relief- Some temperature and indicating-devices are digital electronic by design, thus inherently more accurate and sensitive. This feature permits the IED readout full range scale to be as much as 25 times the reference value with improved sensitivity.and accuracy.
Alternate Test: Electronic digital temperature measuring and indicating devices having an accuracy within Code requirements ( 2%) at the temperature measured may t'e used and substituted for non-digital devices where physical configuration permits.
2.6.1.1.2 Evaluation: Using digital instrumentation to measure temperature is a reasonable alternative to the Code because the measurement accuracy of the instrument meets the accuracy requirements even though the range capabilities of the instrument exceed _that allowed by the Code.
Based on the licensee's proposal tc use temperature instrumentation-that is more accurate than required by Sectien XI, relief should be granted from the requirements of Paragraph IWP-4120 as requested.
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- 3. VALVE TESTING PROGRAM The following SCE&GC valve relief requests were evaluated against the requirements of the ASME Code,Section XI, 10 CFR 50.55a, and applicable NRC positions and guidelines. Each relief request is summarized and the licensee's basis for requesting relief is presented. The reviewer's evaluation and recommendation follow. The requests are grouped according to topic or system and valve Category.
3.1 All Systemi 3.1.1 Ra9id-Actino Valves 3.1.1.1 Relief Reoues1 The licensee has requested relief from the valve stroke timing requirements of Section XI, Paragraph !WV-3417(a), for all rapid acting valves in the IST program and proposed to apply a maximum stroke time limit of two seconds to these valves.
3.1.1.1.1 Licensee's Basis for Reouesting Relief--Valves with stroke times 52 seconds may exceed the 50% increase limitation from the previous test due to normal manual response error.
Alternate Testing: Exercise valves full-stroke to the nearest second not to exceed a maximum stroke time of 2 se.conds.
3.1.1.1.2 Evaluation--Rapid-acting valves are defined as those valves which stroke in 2 seconds or less. Industry experience has shown that these valves are difficult to accurately stroke time using presently available methods of measurement and the results are subject to variations due to influences other than valve condition. Variations in the response time of the personnel timing the valve stroke can result in variations in the stroke times. This could easily 1.ause the measured stroke time to exceed the Section XI limits. This might require corrective action on a non-degraded valve. The licensee's proposal to assign a maximum stroke time limit of 2 seconds to these valves and to take corrective action upon exceeding that limit is in accordance with GL 89-04, Position 6. Therefore, 17
f
.. e the proposal. is essentially equivalent:to the Code requirement and allows- an adequate assessraent of operational ~ readiness a3d provides a reasonable
- alternative- to the Code ~ requirements, Based on *heEdetermination that compliance with the Code requirements-is impractical and that the licensee's proposal follows the guidance presented in GL_89-04, Position G, which provides a reasonable alternative to_the Code requirements, relief should be. granted as requested.
p i 3.2 Comoonent Coolino Water System 3.2.1- CJteoory C Valves _-
[
u
[ 3.2.1.1 flelief Reouest.. The licensae has requested relief from
[ exercising' valves XVC-9680A and -96808, component cooling system service
) water supply checks, according-to the requirements of Section XI, Paragraph IWV-3522, and _ proposed to test -tnese valves - during refueling outages'.
l 3.2.1.1.1~ Licensee's-Basis for ReouestinSL R elief--Flow testing these' valves during-plant operation would inject raw service water into the
- component cooling water system. Thic.causas chemistry control problems in the component cooling system. Flushing and chemistry control recovery iduring cold shutdown will delay restart a minimum of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
1
[ ' Alternate Test: Valves will be tested during refueling shutdowns when time
.- ' will permitisubsequent flushing to clean the tested portions of the -
- component cooling system.
3.2.1.1.2 Evaluation--It is impractical to part- or full-stroke exercise these valves using flow quarterly during power operation or during
-cold shutdowns _-because the only flow path is from the service water system '
into the component cooling water system. Flow from the service water system would cause significant chemical contamination of the component cooling
' water system. The component cooling water is chemically treated to inhibit corrosion and the addition of the raw service water would upset the chemical 18
balance, which could result in increased corrosion rates, maintenance, and fouling of heat transfer surfaces. To allow full-stroke exercising these valves with flow quarterly would require system redesign and modifications, which would be costly and burdensome to the licensee. Additionally, it is impractical-to exercise these valves during cold shutdowns because the extensive flushing required to restore the cleanliness of the component cooling water system could delay reactor startup, Viich would also be burdensome to the licensee. The licensee's proposal to full-stroke exercise these valves with flow during refueling outages provides a reasonable alternative to the Code test frequency requirements.
Based on'the determination that compliance with the Code requirements is impractical, and considering the licensee's proposal and the burden on the licensee if the Code requirements are imposed, relief should be granted from the exercising frequency requirements of Section XI as requested.
3.3 [.hemical and Volume Control Svittm 3.3.1 Cateoory C Valves 3.3.1.1 Relief Reoun 1 The licensee has requested relief from exercising valves XVC 8481A, -8481B, and 8481C, charging pump discharge checks, according to the test frequency requirements of Section XI, Paragraph-IWV-3520, and proposed to part-stroke exercise them quarterly and to full-stroke exercis? them each refueling outage when the reactor vessel head-is removed.
3.3.1.1.1 Licensee's 03 sis for Requestino Relief--Exercising these valves during normal operations would require establishing flow to the RCS. This would inject boron and shut down the plant. Exercising these valves during cold shutdown could cause cold temperature overpressurization of the RCS and/or the reactor pressure vessel.
19
Alternate Test: These valves will be partial exercised each quarter and full flow exercised each refueling outage when the vessel head is removed.
3.3.1.1.2 Evaluation -It is impractical to full-stroke exercise these check valves during power operation because the only full flow path is into the RCS. Using this flow path during power operation could cause a loss of pressurizer level control and a resulting reactor trip. It is impractical to full-stroke exercise these valves during cold shutdown as the RCS does not contain sufficient expansion volume to accommodate the flow required and a low temperature overpressure condition could result. To allow full-stroke exercising of these valves quarterly would require system redesign and modifications. This would be costly and burdensome to the licensee. The licensee's proposal to part-stroke exercise these valves quarterly and to full-stroke exercise them each refueling outage provides a reasonable alternative to the Code test frequency requirements.
Based on the determination that compliance 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 are imposed, relief should be granted as requested.
3.4 Emeroency Feedwater System 3.4.1 Cateoory C Valve _s 3.4.1.1 Relief Reouts_t. The licensee has requested relief from exercising valves XVC-1022A and -10228, turbine driven emergency feedwater pump service water supply checks, according to the test frequency and method requirements of Section XI, Paragraph IWV-3520, and proposed to disassemble and inspect them during refueling outages, 3.4.1.1.1 Licensee's Basis for Reauestino Relief--Testing those valves during plant operations or cold shutdown cculd introduce service water into the emergency feedwater system and eventually into the steam generators causing severe chemistry control problems.
20
Alternate Tg.d: Valves will- be disassembled and inspected each refueling shutdown.
3.4.1.1.2 Evaluation -It is impractical to full or part-stroke exercise these velves with flow under any plant operating conditions. This is because the only possible flow paths are from the service water supply through the emergency feedwater pump ano into either the steam generators or condensate storage tank. Neither flow path can be used without contaminating the steam generators or the condensate system with service water because there are no vents or drains installed to allow complete draining and flushing of the affected sections of piping, Any injection of service water would result in severe chemistry control problems and steam generator chemical stress damage.
The licensee has proposed to disassemble and inspect these valves each refueling outage. Disassembly, inspection and manual full-stroke of the valve disk can adequately ascertain a check valve's internal condition.
However, disassembly and inspection should be used to manually exercise check valves open and/or shut only when full forward flow or reverse flow testing is impractical, The NRC staff considers check valve disassembly and inspection to be a maintenance procedure that is not a test and not equivalent to the exercising produced by fluid flow as required by Section XI. This procedure has some risks, which may make its routine use as a substitute for testing undesirable when some testing method is possible.
Check valve disassembly is a valuable maintenance tool that can provide a great deal of information about valve internal condition and, as such, should be performed under the maintenance program at a frequency commensurate with the valve type and- service.
The licensee should actively pursue the use of alternate testing
- nethods to full-stroke exercise these valves, such as using non-intrusive diagnostic techniques to demonstrate whether they swing fully open during partial flow testing. When valve operational readiness cannot practically be determined by observation of system parameters, disassembly and inspection may be used as an alternative. However, the licensee should j
perform post maintenance testing (e.g., forward flow or reverse flow closure L
21 l
capability) of:each valve prio_r to returning it to: service following the disassembly:and inspection procedure, The licensee'siproposed disassembly and inspection program is not thoroughly stated and does not include corrective action (s) that will be taken if: a valve fails the inspection. Therefore, a determination that the proposal provides a reasonable alternative to the code requirements cannot be made.- However, a check valve inspection program performed in accordance with GL 89-04, Position 2, " Alternative to_ Full Flow Testing of Check Valves," can adequately determine valve condition and provides a reasonable alternative to the Code requirements.
Based on-the determination that compliance with the Code requirements l is impractical and considering the. licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted provided the licensee performs check valve disassembly and inspection in accordance with GL 89 04, Position 2.
g -3.4.1.2 : Relief Recuest. The licensee has requested relief from exercising valves XVC-1034A and 10343, motor driven emergency feedwater pump service water supply checks, according to the test frequency and method requirements of Section XI, Paragraph IWV-3520, and proposed to disassemble and inspect them_during refueling outages.
3.4.1.2.1 Licensee's Basis for Reauestino Relief--Testing these valves during plant operations or cold shutdown could introduce service <
water into the emergency feedwater system and eventually into the steam generators causing severe chemistry control problems.
p' Alternate' Test: Valves will be disassembled and inspected each refueling shutdown..
3.4.1.2.2 Evaluation--It is impractical to full or part-stroke exercise these valves with flow under any plant-operating conditions. This is because no test flow path exists. The only possible flow path is from - '
the service water supply through the emergency feedwater pump and into 22
either the steam generators or the condensate storage tank. Neither flow path can be used without contaminating the steam generators or the condensate system with service water because there are no vents or drains installed to allow complete draining and flushing of the affected sections of piping. Any injection of service water would result in severe chemistry control problems and steam generator chemical stress damage.
The licensee has proposed to disassemble and inspect these valves each refueling outage. Disassembly, inspection and manual full-stroke of the valve disk can adequately ascertain a check valve's internal condition.
However, disassembly and inspection should be used to manually exercise -
check valves open and/or shut only when full forward flow or reverse flow testing is impractical. See discussion in Section 3.4.1.1.2 of this report.
The licensee's proposed disassembly and inspection prograni is not thoroughly stated and does not include corrective action (s) that will be taken if a valve fails the inspection. Therefore, a determination that the proposal provides a reasonable alternative to the Code requirements cannot be made. However, a check valve inspection program performed in accordance with GL 89-04, Position 2 " Alternative to Full Flow Testing of Check Valves," can adequately determine valve condition and provides a reasonab76 alternative to the Code requirements.
Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted i provided the licensee performs check valve disassembly and inspection in accordance with GL 89-04, Position 2.
3.5 lafety In.iection System 3.5.1 Cateaory A/C Valves 3.5.1.1 Relief Reauest. The licensee has requested relief from exercising the high head Si injection header check valves, XVC-8995A thru C,
-8997A thru C (cold leg), XVC-8990A thru C. and -8992A thru C (hot leg),
23
4 according to the test frequency requirements of Section XI, Paragraph IWV 3520, and proposed to full stroke exercise these valves during refueling outages, 3.5.1.1.1 Licensee's Basis for Reouestina Relief -Testing these valves during plant operations will require establishing charging flow into the reactor coolant loop, placing unnecessary thermal stresses on the high head injection piping and reactor coolant piping branch nozzles. Testing these valves during cold shutdown also requires establishing charging flow th*ough the high head injection lines, kith the !K such a low pressure and temperature, there could be an uncontrolled inje:' in of a large volume of water, vhich could cause a pressure spike in the . .<m and exceed the pressure-temperature limits.
Alternate Tes.1: These valves will be tested during each refueling outage when the vessel head is removed and the refueling pool can be used to contain the large volume of water.
3.5.1.1.2 Evaluation--It is impractical to exercise these valves during power operation because that would require injecting relatively cold water into the RCS. The resultant thermal shock could cause premature failure of the injection nozzles, it is impractical to exercise these valves during cold shutdown because the RCS has insufficient expansion volume to contain the necessary finw rate. Full-stroke exercising durkg cold shutdowns could cause an RCS low temperature overpressure condition.
System redesign and modification would be needed to allow full-stroke exercising these valves quarterly or during cold shutdowns, which would be burdensome to the licensee. The licensee's proposal to full-stroke exercise these valves each refueling outage provides a reasonable alternative to the Code test frequency requirements.
The licensee must verify these parallel valves are individually full-stroke exerch ed during testing. The licensee should use the guidsnce presented in GL 80-04, Positica 1, for this verification.
24
^
Based on the determination that compliance is impracticable and burdensome and considering the licensee's proposal, relief should be granted from the-Section XI test frequency requirements as requested.
3.5.1.2 Relief Reoues1 The licensee has requested relief from exercising valves XVC-8948A, -8948B, -8948C, -8956A. 8956B, and 89560, 51 accumulator discharge checks, according to the test frequency requirements of Section XI, Paragraph IWV 3520, and proposed to full-stroke exercise them during refueling outages.
3.5.1.2.1 Licensee's Easis for Reouestina Relief--Testing those valves during plant operations will require initiating flow from the SI accumulator to the RCS. The Si accumulators do not have the required pressure to overcome normal RCS pressure, therefore, flow could not be established. During co?d shutdown, injecting an additional large concentration of boron contained in the Si accumulators into the RCS woLid require a large volume of reactor makeup water to dilute the boron concentration in the RCS. This would be inconsistent with normal startup procedures.
Alternate Testina: Valves will be exercised to the position required to fulfill their function during each refueling shutdown. Nitrogen pressure 75 psi will be used as the moving force for Si accumulator water. An acoustic method will be used in conjunction with a local leak rate test to qualify the opening and closing of each valve.
3.5.1.2.2 Evaluation--These valves canr.ot be full- or part-stroke exercised during power operation becau>e the only flow path is into the RCS. The operating accumulator pressure cannot overcome normal operating RCS pressure to establish flow. It is impractical to full-stroke exercise these valves during cold shutdowns as the RCS does not contain sufficient expansica volume to accept the flow required. System redesign and modification are needed to allow full-stroke exercising quarterly or during cold shutdowns. This would be costly and burdensome to the licensee. The proposal to full-stroke exercise these valves each refueling outage provides a reasonable alternative to the code test frequency requirements.
25
The licensee has proposed to verify the full-stroke exercising of these valves using an acoustic technique and to verify their closure each refueling outage by leak rate testing. Leak rate testing these valves during refueling outages provides information to assess their closure capability, Verification of full-stroke open capability using acoustic methods has been demonstrated effective, when a time of arrival or other such scheme is utilized, lhis technology is relatively new and not all methods have been shown to be effective. The technique used must yield adequate informaticn to assess valve operational readiness. The technique should be completely documented in the IST program per GL 89 J4, Position 1, on full flow testing of check valves. Testing these valves per Fosition 1 provides an adequate level of quality and safety and an acceptable alternative to the Code.
Based on the determination that compliance with the Code requirements is impracticable and burde...ome, and considering the licensee's proposal, relief should be granted provided the licensee complies with GL 89 04, Position 1. .
3.5.1.3 Relief RtqugE1 The licensee has requested relief from exercising valve XVC-8993C, high head Si loop C het leg injection check, according to the test frequency requirements of Section X1, Paragraph IWV-3520, and proposed to full-stroke exercise this valve during refueling outages.
3.5.1.3.1 Licensee's BAjis for Rgauestj ao Relief--Sinc. ,cion for the charging pumps vuld be shifted to the reueling water storage tank to perform this test, testing this valve would cause an inadvertent boration due to the high concentration of boric acid in the refueling water storage tank, thus a plant shutdown, in addition, testing this valve during normal operation would cause excessive thermal shock to the SI to RCS piping.
During cold shutdown, the RCS does not have the vo'ume to contain the large amount of water required to test this valve, thus having a potential for
, exceeding the m:ximum presture for these low temperatures.
i e
1 26 !
l l
l
l AlternJte Tett: Valve will be tested during each refueling outage when ,ie vessel head is removed and the refueling pool can be used to contain the large volume of water.
3.5.1.3.2 Ly1_1 qui?a -It it i gractical to exercise this valve during power operation as that would require injection of relatively cold, highly borated water into tha RCS. This could cause a power reduction and thermal shock to the injection nozzles and possibly result in their premature failure, it is impractical to exercise this valve during cold shutdown because the RCS has insufficient expansion volume to accommodate the high flow rate. This could lead to a low temperett.re overpressure condition and damage to RCS componentr. System redesign and modification woulJ be needed to allow full-stroke exercising of this valve quarterly or during cold shutdowns. This would be costly and burdensome to the licensee. The licensee's proposal to full-stroke exercise this valve each refueling outage provides a reasonable alternative to the Code test frequency requirements.
Based on the determination that compliance with the Code requirement to part- or full-stroke exercise this valve quarterly and during cold shutdowns 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 are imposed, relief should be granted as requested.
3.5.2 Cateaory B Valves 3.5.2.1 Relief Reqqgit. The licensee has requested relief from exercising valves XVC-8801A and -8801B, high head Si cold leg injection isolation valves, according to the test frequency requirements of Section XI, Paragraph IWV-3410, and proposed to full-stroke exercise them during refueling outages.
3.5.2.1.1 Licensee's Basis fotJgquestirLq Relief--Testing these valves during normal operation could inject a high concentration of boric acid into the high head injection lines and thus into the RCS causing an inadvertent boration and plant shutdown. During cold shutdown, exercising l
27
)
1 a
. ?
4 these valves could cause mioration of the high concentration boric acid into the high head injection lines, which are not heat traced, causing solidification and blockage of these lines.
Alternate Test: Valves will be exercised during refueling shutdowns 3.5.2.1.2 [yaluation--It is impractical to exercise these valves during power operation as that could result in injection of a high concentration of boric acid into the RCS. This wouio causo power fluctuations and could result in plant shutdown. Exercising these valves during cold shutdowns :ould result in migration of the high concentration boric acid into the RCS cold leg high head SI lines. This could cause solidification and blockage of the lines because they are not heat traced.
Flushing these lines is time consuming and would likely delay the return to power. System redesign and modification would be needed to allow full-stroke exercising of these valves quarterly or during c31d shutdowns.
This would be costly and burdensome to the licensee. The licensee's proposal to full-stroke exercise these valves each refueling outage provides a reasonable alternative to the Code test frequency requirements.
Based on the determination that compliance with the Code test frequency requirements is impracticable and burdensome, and since the licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted as requested.
3.5.3 Cateoory C Valves 3.5.3.1 Relief Reouest. The licensee'has requested relief from exercising valve XVC-8926, charging pumps refueling water storage tank suction. check., according to the test frequency requirements of Section XI, Paragraph IWV-352v, and proposed to part-stroke exercise it during cold shutdowns and to full-stroke exercise it during refueling outages.
3.5.3.1.1 Licensee's Basis for Reauestino Relief--Full flow testing this valve during normal plant operations would cause an inadvertent boration due to the high concentration of boric acid in the refueling water storage tank, thus a plant shutdown. Full flow testing this valve during 28
cold shutdown could cause low temperature overpressurization due to insufficient discharge expansion _ volume in the RCS.
Alternate Test: The valve will be partially flow tested during cold shutdown and full flow tested during each refueling when the refueling cavity can be used to contain the large volume of water.
3.5.3.1.2 Evaluation -It is impractical to full-stroke exercise this valve during power operation because the only full flow path is into the RCS, Design basis flow cannot be established into the RCS during power operation as that could cause a loss of pressurizer level control and reactor trip. The suction source for flow testing this valve is the refueling water storage tank, which has a high boric acid concentration.
Flow into the RCS from this source could result in a plant shutdown.
It is impractical to full-stroke exercise this valve during cold shutdown because the RCS does no* contain sufficient expansion volume to
-accommodate the flow required. 'his could cause a low temperature overpressure condition and aamage RCS components. System redesign and modification would te needed to allow full-stroke exercising of this valve quarterly or during cold shutdowns. This would be costly and burdensome to the licensee. The proposal to part-stroke exercise this valve during cold shutdowns and to full-stroke exercise it each refueling outage provides a reasonable alternative to the test frequency requirements.
Based on the determination that compliance with the Code test frequency requirements is impracticable, the licensee's proposal providt a reasonable alternative to the Code, and considering the burden on the licensee if the Code requirements are imposed, relief should be granted as requested.
3.6 Reactor Buil.d_ ipa Sorav System 3.6.1 Cateoory A/C Valves 3.6.J.1 Relief Reauest. The licensee has requested relief from exercising valves XVC-3009A and -3009B, reactor building spray header checks, according to the test method and frequency requirements of 29
Section XI, Paragraph IWV 3520, and proposed to disassemble, inspect, and i
manusily full stroke exercise them during reft.eling outages.
< 3.6.1.1.1 Littnte'LDjtsis for Reauestino Relief- low testing these valves during operations would require placing the reactor building spray system in operation which would result in dousing the containment and F
fil*ers, c-L (L ernate Ten: Valves will be disassembled and inspected for operability
( during each refueling shutdown.
3.6.1.1.2 f.YJLl R110D it is impractical to exercist these valves with flow during any plant mode as that would result in spraying the containment ard filters causing damage to lagging, electrical equipment.
L etc. The licensee has proposed to disassemble and in:pect these valves each refueling outage. Disassembly, inspection and manual full stroke of the vd ve disk can idequately ascertain a che(k valve'$ internal condition.
1
/
However, disassembly and inspection should be used to manually exercise E' check valves open and/or shut only when full forward flow or reverse flow testing is impractical. See discussi'a in Section 3.4.1.1.2 of this report.
The licensee's proposed disassembly and inspec. tion program is not thoroughly stated and does not include corrective action (s) that will be _
I taken if a valve fails the inspection. Therefore, a determination that the proposal provides a reasonable alternative to the Code requirements cannot be made. However, a check valve inspection program performed in accordance r
with GL 09-04, Position 2 " Alternative to Full Flow Testing of Check i Valves," can adequately determine valve condition and provides a reasonable
_ alternative to the Code requirements.
Based on the determination that compliance with the Code requirements E is impractical and considering the licensee's proposal and the burden on the
, licensee if the Code requirements were imposed, relief should be granted provided the licensee performs check valve disassembly and inspection in accordance with GL 89 04, Position 2.
30 1
i e
3.6.2 O ltgory C Valy11 3.6.2.1 RelicL_Rm ucit. The licensee has requested relief from exercising valves XVC-3013A and 30138, reactor building spray sodium hydroxide supply checks, according to the requirements of Section XI, Paragraph IWV 3520, and proposed to disassemble, inspect, and manually full stroke exercise them during refueling outages.
3.6.2.1.1 Litt3see's Balls for Requestina Relie( -Testing these l
valves dtiring plant operation or cold shutdown would result in dousing the containment and filters or pumping sodium hydroxide into the refueling water storage tank.
Alternate Teil: These valves will be disassembled and inspected for operability during each refueling shutdown.
3.6.2.1.2 Lyals tion- Exercising these valves with ficw during any plant mode would require either spraying the containment or injecting highly corrosive sodium hydroxide into the refueling water storage tank via the reactor building spray system full flow pump test loop. The licensee has proposed to disassemble and inspect these valves each refueling outage.
Disassembly, inspection and manual full stroke of the valve disk can adequately ascertain a check valve's internal condition. However, disassembly and inspection should be used to manually exercise check valves open and/or shut only when full forward flow or .everse flow testing is impractical. See discussion in Section 3.4.1.1.2 of this report.
The licensee's proposed disassembly and inspection program is not thoroughly stated and does not include corrective action (s) that will be taken if a valve fails tne inspection. Therefore, a determination that the proposal provides a reasonable alternative to the Code requirements cannot be made. However, a check valve inspection program performed in accordance with GL 89 04, Pcsition 2 " Alternative to full flow Testing of Check Valves," can adequately determine valve condition and proitides a reasonable alternative to the Code requirements.
31
Based on the determination that compliande with the Code requirements is impractical and considering the licensee's proposal and the burden on the licent.ee if the Code requirements were imposed, relief should be granted provider 1 the licensee performs check valve disaAsembly and inspection in accordance with GL 89 04, Position 2.
32
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,e '
i l
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1
+
5 5
I f,
I y
APPEN0lX A P&l0 LIST I
s A-1
,_ .. ... -- _. . _ . . - - _ . _ - . - . . _ , . , _ . _ _ _ _ _ , _ , _ . _ _ . - . . . . - - _ _ . _ _ . , _ - - ~ - _ . _ _ . _ , . _ _ _ . _ _ _
\
APPENDIX A P&l0 LIST The P&lDs listed below were used during the course of this review.
System P&lD Revision CRDH Cooling Water D 302 852 6A Reactor Building Purge Supply and Purge Exhaust D 912 103 12 Steam Generator Blowdown D 302 781 19A Component Cooling D-302 611 21A D 302 612 17 D 302 613 12 Chemical and Volume Control 0 302 671 4 D 302 672 4 D 302 673 6 D 302 675 6A D 302 677 3 Diesel Generator D 302 351 7 Demineralized Water D-302 715 19 feedwater D 302 083 29 Emergency Feedwater D 302-085 22 Fire Service D 302 231 22 l'ost Accident Hydrogen Removal D 302 861 25 Instrument Air D 302 273 8 Main Steam 0-302 011 21 Reactor Makeup Water D 302 791 15A Reactor end Auxiliary Building Sump Pumps D 302 821 19 Nitrogen B*anketing D 302 311 6 Reactor Coolant 0-302 601 7 D 302-602 IIA Residual Heat Removal 0 302 641 5 Station Air D 302-241 25 A3 i
j
System P&lD Revision Spent Fuel Cooling D-302-651 25A Safety injection D 302-691 7 6 302 692 SA D-302-693 4 Reactor Building Spray 0 302-661 22 Nuclear Sampling D 302-771 21A D-302-772 11 Service Water D 302 221 15 D 302 222 25 Chilled Water D-302 841 18 D 302-842 12 D 302 843 11 Waste Processing 0-302-735 3 b
a A-4
4 d APPENDIX B
< IST PROGRAM AN0MAllES IDENTIFIED IN THE REVIEW 4
9 t
B-1 k
APPENDIX B IST PROGRAM AN0MAllES IDENTIFIED DURING THE REVIEW Summarized below are inconsistencies and omissions in the licensee's program noted during this review. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
- 1. The licensee has requests. relief from measuring bearing temperature, inlet pressure *nd differential pressure on the diesel generator fuel oil transfer pumps (see Section 2.1.1.1 of this report) and proposed to measure pump flow rate and vibration once per month and to assign administrative limits for pump flow rate. The licensee's proposed corrective action acceptance criteria are unacceptable since they could allow the pump to degrade to less than one half normai capacity before requiring corrective action. Relief should be granted provided the calculated flow rate meets the accuracy requirements of Table IWP 4110 1. Relief should not be granted to use the proposed acceptance criteria. The licensee should establish flow rate reference values and use the acceptance criteria of Section XI, Table IWP 3100-2.
- 2. The licensee has requested relief from establishing fixed reference values for flew and differential pressure for their service and chilled water pumps (see Sections 2.2.2.1 and 2.5.1.1 of this report) and proposed to use pump curves to compare flow and differential pressure.
Acceptance criteria based on the curve should not confilet with Technical Specification or Facility Safety Analysis Report operability criteria. Since the levels of vibration may vary significantly depending on where the pump is operating relative to the pump curve, a set of vibration reference values would have to be established for each pump curve used that give equivalent protection as provided by the Code. Relief should be granted provided the insitu pump curves are develope'd, or manufacturers curves are validated, when the pump is known to be operating acceptably, as described in this report, and acceptance criteria for vibration measurements give equivalent protection as provided by the Code.
B3
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- 3. The licensee has requested relief from the allowable range requirements of Section XI for flow and differential pressure measurements on their service water pumps (see Section 2.2.3.1 of this report) and proposed to establish expanded ranges to accommodate added instrument errors.
The licensee has not demonstrated that the proposed acceptance criteria will give adequate assurance of pump operational readiness when applied to their pump test parameter vaiues during testing.
Service water system P&l0s, dated 3/13/89, show a flow element and indicator installed in each service water header such that each header can be isolated, or split it operated in parallel, and individual pump flow rates can be obtained. Since the licensee has not shown that using the Code specified acceptance criteria is impractical or that it imposes an excessive hardship without a compensating benefit to safety, and since the licensee's proposed alternati"e does not provide a reasonable alternative to the Code requirements, relief should not be granted as requested.
- 4. The licensee has requested relief from the requirement of Section XI to measure ' flow rate of the charging pumps (see Section 2.4.1.1 of this report) and proposed to measure flow rate during refueling outages. The proposed alternative has not been shown to provide an acceptable level of quality and safety and relief should not be granted from the Code requirements.
The licensee should cuntinue to measure pump flow rate quarterly. The licensee should also perform the flow test during refueling outages when a full flow path to the RCS is available and comply with the Code instrument accuracy requirements. If the licensee determines that the Code flow rate instrument accuracy or acceptance criteria requirements cannot be met during quarterly testing the licensee should request relief from these requirements and justify their proposed alternatives. The licensee should specifically address the individual B-4
l 6
instrument and total loop accuracies and show the proposed testing will give adequate assurance of pump operational readiness and provide a reassnable alternative tn the Code requirements.
- 5. In the licensee's program for testing valves, on p.13, Paragraph 6.2.4, GTP 302, the statement is made that "If a power operated valve fails to exhibit the required change of valve stem or disk position or exceeds its maximum allowed stroke time by this testing, corrective action will be initiated i* mediately, if the test deficiency is not, or cannot be corrected within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the valve will be declared inoperable."
This statement conflicts with GL 89-04, Position 8, which states in part, "...it is the staff's position that as soon as the data is recognind as being within the Required Action Range for pumps or exceeding the limiting value of full-stroke time for valves, the associated component must be declared inoperable and the Technical Specification Action time must be started." In other words, if a valve fails to exhibit the required change of stem or disk position or exceeds its specified limiting value of full-stroke time, it must be declared inoperable immediately, not af ter a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period has elapsed. The licensee should revise the IST program to agree with this staff position.
.6. GTP 302, Attachment Vil, Table C, p.1 of 1, Maximum Stroke Time Determination, presents guidance that may be used to calculate maximum stroke times for power operated valves. This Table does not appear to be in accordance with the guidance presented in GL 89-04, Position 5.
All valves with nominal full-stroke times greater than 2 seconds could have stroke times that exceed the limits of Section XI, Paragraph IWV-3413(c), by a large margin before exceeding the calculated maximum limiting value of full stroke time. The continued operational readiness of any valve would be questionable if that valve's full-stroke time doubled, as allowed by Table C, when compared to the stroke time of the previous test.
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lhe licensee should revise Table C to establish the maximum value of d limiting stroke time for power operated valves in accordance with the guidance presented in GL 89 04, Position 5. Corrective action should be taken as described in the " Minutes of the Public Meetings on Generic Letter 89 04, response to question 34."
- 7. The licensee has requested relief (Relief Request E.2) to test various valves during cold she % wn when those valves cannot be tested quarterly during power operation. This relief request is unnecessary because Section XI, Paragraphs IWV-3412 and -3522, specifically allow valve testing to be deferred to cold shutdown if that testing is impractical during power operation. The licensee should delete this relief request and include the information contained in the Alternate Test, which explains how cold shutdown testing will be conducted.
- 8. It is unclear how reverse flow closure of Category A/C check valves XVC-7541, -7544, -8046. -8861, and 8947 is verified each cold shutdown. These valves might be verified in their closed safety function position by a leak rate test, such as Appendix J Type C.
However, this is usually performed only during reactor refueling outages. This test frequency does not meet the Section XI requirements. The licensee should justify a test interval Jeyond that allowed by the Code in a relief request or test these valves in accordance with the Code test frequency requirements. If closure testing is done at each cold shutdown, tha test should be described in the cold shutdown justification.
- 9. The licensee has requested relief (Relief Request N.3) from the Code test data trending and increased test frequency corrective action
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requirements for Category A reactor building purge supply, XVB 0001A and -0001B, and purge exhaust valves, -0002A and -00028. These valves will be leak rate tested every 6 months per plant Technical Specifications. The combined leakage rate allowed for both valves equals the Technical Specification limit for each valve, 3620 cc/ min.
This relief request is unnecessary. The Code requires these valves to be leak tested every two years. The licensee is leak testing them every six months, which is conservative. The licensee proposed not to B6 !
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> trend leakage. Trending of containnent isolation valvo leakage rates per IWV 3427(b) is exempted by GL 89 04, Position 10. Relief is not requested from !WV-3426 and 3427(a). The request indicates that these valves are leak tested individually and the test results are combined and compared to the leak rate limit applicable to either valve. also conservative. Therefore, this relief request may be withdrawn and compliance with GL 89 04, Position 10, indicated in the program. If relief is needed for reasons not addressed above the request should be revised and resubmitted.
- 10. The licensee has proposed testing the following valves during cold shutdowns when the reactor coolant pumps are secured at RCS half pipe fill conditions. These cold shutdown justifications are unacceptable as this plant condition will not occur each cold shutdown and the test interval could be as long as frca refueling outage to refueling outage, which is not in acc.ordance with the Code test frequency requirements.
The licensee should provide a relief request that addresses and justifies this extended test interval in the IST program or test these valves in accordance with the Code test frequency requirements.
Cold Shutdown Justification Id. Valve ld. Function CS-CC-1 XVC-9570 & -9602 containment component cooling water supply check valves CS CC-2 XVG 9568, 9600, containment component cooling water 9605, & 9606 supply and return valves CS-CC 3 XVG-9625 & -9626 non essential containment component cooling water header isolation valves CS CC 4 XVC-9632 & -9633 non-essential containment component cooling water header isolation check valves CS CVCS 7 XVT 8102A. 8102B, reactor coolant pump seal water
& 9102C injection
- 11. The licensee has included pressurizer auxiliary spray valve XVT-8145 in the IST program and proposed to test it during cold shutdowns. This proposal is acceptable. However, the downstream check valve 8377 is not in the program. This check valve must be included in the program if credit is taken for operational readiness of the pressurizer auxiliary spray flow path because it must change position to permit l
flow in the line. The licensee should review the safety-related function of this valve and revise the IST program to include this valve as necessary.
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- 12. The licensee stated in the 151 Valve Test t.ist, p. 7 of 33, that the 8 safety position of valv6 XVC 8440, volume control tank outlet check, is closed and that it is being full stroke exercised quarterly. This does not appear to be the case because the motor operated volume control tank outlet valves upstream of this check valve are being full stroke exercised during cold shutdowns (see Cold Shutdown Justification CS CVCS 1). The licensee should verify the testing frequency of valve XVC 8440 and revise the IST program as r.ecessary.
- 13. Diesel generator system Drawing No. lHS 22 006 was not available for review. This drawing shows the following valves:
10977A 10977B 10978A 10973B 10998A 109980 10999A 10999B 20950A 10950B A complete evaluation of the diesel generater system components that should be included in the IST program and the testing of those components cannot be performed. Additionally, valve 20950A, listed above and on p. 9 of 33 in the 151 Valve Test 1.ist appears to be a typographical error. The licensee should address this inconsistency.
- 14. The licensee has requested relief from exercising several check valves according to the Section XI test frequency and method requirements (see Sections 3.4.1.1, 3.4.1.2, 3.6.1.1, and 3.6.2.1 of this report) and proposed to disassemble and inspect them during refueling outages.
Disassembly, inspection and manual full-stroking of the valve disk can adequately ascertain a check valve's internal condition. However, disassembly and inspection should be used to manually exercise check valves open and/or shut only when full forward flow or reverse flow testing is impractical. The NRC considers check valve disassembly and inspection to be a maintenance procedure not a test equivalent to exercising produced by fluid flow as required by Section XI. This procedure has some risks, which may make its routine use as a substitute for testing undesirable when some testing method is possible. Check valve disassembly is a valuable maintenance tool that can provide much information about valve internal condition and, as B-8
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such, should be performed under the maintenance program at a frequency commensurate with the valve type and service.
The licensee should actively pursue the use of alternate testing methods to full stroke exercise these valves, such as using non intrusive diagnostic techniques to demonstrate whether they swing fully open during partial flow testing or closed when flow has ceased.
When valve operational readiness cannot practically be determined by observation of system parameters, inspection may be used as an alternative, however, the licensee should perform post maintenance testing (e.g., forward flow and reverse flow closure capability) of each valve prior to returning it to service following tle disassembly and inspection procedure.
The licensee's proposed disassembly-and inspection program is not thoroughly stated and does not include corrective action (s) that will be taken if a valve fails the inspection. A determination that the proposal prcvides a reasonable alternative to the Code requirements cannot be made. However, a check valve inspection program performed in accordance with GL 89 04 Position 2, can adequately determine valve condition and provides a reasonable alternative. Therefore, relief should be granted provided the licensee performs check valve disassembly and inspection per GL 89-04, Position 2.
- 15. The licensee has requested relief from exercising the accumulator discharge check valves according to the Section XI test method and frequency requirements. The licensee has proposed (see Section 3.5.1.2 of this report) to full stroke exercise them during refueling outages and to verify this using an acoustic technique. Relief should be granted provided the licensee complies with GL 89-04, Position 1.
- 16. The licensee should verify that the proposed full-stroke exercise of valves XVC 8973A, -8973B, 8973C, -8974A, and 8974B, low head Si header checks, is in fact a full stroke exercise as defined in GL 89-04, Position 1, and that the valves are being individually B-9
. 0 full stroke exercised even with the parallel flow paths. (See Cold Shutdown Justification C5 51 5)
- 17. Simple check valves that serve a vacuum breaker function are to be tasted quarterly, if practical, in accordance with the requirements of Section XI, Paragraph IWV 3520, for Category C check valves. The licensee should review the design and testing of valves 3014A and 3014B using this guidance. (See ISI Valve Test List, p. 26 of 33)
- 18. The following miscellaneous errata were identified during the program review and should be corrected as necessary, a) The licensee has incorre:tly listed the location of check valve 64898 in the 151 Valve Test List. The location should be Dwg. 842, Cord. C-8. (See ISI Valve Test list, p. 32 of 33) b) The licensee has categorized valves XVC-7541 and -7544 Category A/C in the ISI Valve Test list but has incorrectly categorized them Category C in Cold Shutdown Justification CS-AC-2.
c) The licensee has categorized valves XCV 9680A and 9680B Category C in the ISI Valve Test List but has incorrectly categorized them Category A/C in Relief Request A.I. Additionally, this relief request is identified as A.1 in the List but is identified as A 5 on the relief request page.
J b d) The licensee has incorrectly listed the location of valve XVT 8104 in the ISI Valve Test List. The location should be Dwg. 675, Cord.
G-4. (See 151 Valve Test List, p. 4 of 33) e) The licensee has incorrectly listed the location of valve XVC-8348C in the ISI Valve Test List. The location should be Dwg. 673, Cord. G-14. (See ISI Valve Test List, p. 6 of 33) f) The licensee has Categorized valves XVC-8481A, -8481B, and -8481C Category C in the ISI Valve Test List but has incorrectly categorized them Category B in their Relief Request B.2.
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g) The licensee has categorized valves XVC 8480A, 84808, and 8480C j Category C in the 151 Valve Test List but has incorrectly categorized l them Category B in Cold Shutdown Justification CS CVCS 10.
h) The licensee has incorrectly categorized valve XVC 6799, reactor l building fire water supply check, as Category A on p.12 of 33 in the ISI Valve Test list when it should bc categorized A/C. Additionally, this check valve has been identified as being a passive valve while the motor operated valve upstream of it has been identified as active. The licensee should address this inconsistency, j
- i) The licensee has not assigned a category designation to valves IFV 478. -488, and 498, main feedwater control valves, and to valves IFV 3321, 3331, and .334), main feedwater control valve bypasses, in the IST program. These globe valves should be Category B and tested in accordance with the Section XI requirements for Category B power operated valves. (See Cold Shutdown Justifications CS-FW 2 and CS-FW-3) j) The licensee has categorized valves XVC 1684A, -16848, and -1684C Category C in the ISI Valve Test List but has incorrectly categorized them Category B in Cold Shutdown Justification CS-FW 4.
l k) The licensee has identifiqd the system containing valve 6054 as l System JR instead of HR on p. 14 of 33 of the ISI Valve Test List.
Additionally, the CS. column indicates MN/A instead of N/A.
- 1) The licensee has categorized valve XVC 2661 Category A/C in the ISI Valve Test List but has incorrectly categorized it Category A in Cold Shutdown Justification CS-IA 1.
m) The licensee has categorized valves XVC 2876A ano 28768 Category l C in the ISI Valve Test List but has incorrectly categorized them Category B in Cold Shutdown Justificatinn CS HS 2.
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. O, n) The licensee has incorrectly listed the locations of relief valves 8708A and 8708B in the ISI Valve Test List. The location should be Dwg. 641. Cord. H 14 and F-14. (See 151 Valve Test List, p. 20 of 33) o) The licensee has incorrectly listed the Active or Passive function of valve XVC 8998A as 1 instead of "A" or "P" in the Active / Passive column on p. 24 of 33 of the 151 Valve Test List.
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