ML20207D403

Requests Relief from ASME Boiler & Pressure Vessel Code, Section Xi,Re Generic Use of Ultrasonic flow-measurement Devices for Section XI Pumps in Response to NRC Request for Addl Info.Fee Paid

ML20207D403
Person / Time
Site:	Sequoyah
Issue date:	08/04/1988
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8808150343
Download: ML20207D403 (14)

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TENNESSEE VALLEY AUTHORITY CH ATTANOOG A, TENNESSEE 374o1 SN 157B Lookout Place AUB 041988 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washing +on, D.C. 20555 Centlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - RELIEF REQUEST FROM AMERICAN SOCIETY OF MECllANICAL ENGINEERS (ASME) BOILER AND PRESSURE VESSEL CODE, SECTION XI, RECARDING GENERIC USE OF ULTRASONIC FLOW-MEASUREMENT DEVICES

References:

1. NRC letter to TVA dated April 5, 1985, "Safety Evaluat.Lon Report. on Sequoyah Inservice Test. Program for Pumps and Valves (IST)"

2. Letter from J. A. Domer, TVA, to E. Adensam, NRC, dated August 16, 1985

3. NRC letter to TVA dated January 19, 1988, "Request for Rollef from ASME Boller and Pressure Vessel Code,Section XI, Inservico Test.ing Program (TAC 61835, 61836)"

In response to a recer.t NRC request for additional informat.lon concerning the une of ultrasonic flow-measuremont devices for testing SQN'sSection XI pumps, TVA is submitting a request, for relief to allow generic uso of ult.rasonic flow-measurement devices for all but, two of SQN'sSection XI pumps. NRC, by reference 3, granted relief to use ultrasonic flow-measurement devices to test SQN's auxiliary feedwater pumps and centrifugal charging pumps. Similar relief is requested in enclosuro 1 to employ ultrasonic flow-measurement, devices for the remainder of SQH'sSection XI pumps with the exception of the boric acid transfer pumps and essential raw cooling water screen wash pumps.

Because this program change contains a request. for rellof from the American Society of Mechanical Engineers (ASME) Boller and Pressuro Vessel Code, Section 11, this item constitutes a st.artup requirement.

TVA requests that this submit.tal be expediently reviewed and a safety Evaluation Report. (SER) be issued to address this chango. If an SER cannot be completed to support, plant restart, a written response document.ing NRC review and concurrence with SQN's pump program would be beneficial. Upon recolpt of either en SER or NRC concurrence, SQN will change its pump program to be consistent with NRC's approved position, fo47 pgSS ABSS $$8Sh,$7 An Equal Opoortunity Employer

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U.S. Nuclear Regulatory Commission 04 E88 Enclosed is a check for tho $150 amendment application fee required by ,

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Please direct questions concerning this issue to D. V. Goodin at

(615) 870-1734.

l Very truly yours, 1

TENNESSEE VALLEY AUTHORITY R, Gridley, Manager Nuclear Licensing and Regulatory Affairs Enclosures ,

I cc (Enclosures): l l

Ms. S. C. Black, Assistant Director for Projects l TVA Projects Division l U.S. Nuclear Regulatory Commlusion One White Flint, North l

11555 Rockville Piko l

Rockville, Maryland 20852 Mr. F. R. McCoy, Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Reglon 11 101 Marietta Street, IN , suite 2900 l

Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Dalsy, Tennessee 37379

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f LNCLOSURE 1 SQN PUMP AND VALVE IN-SERVICE TESTING PROGRAM (SQN FINAL SAFETY ANALYSIS REPORT (FSAR), FECTION 6.8) .

REQUEST FOR RELIEF REGARDING THE USE OF ULTRASONIC FLOW MEASUREMENT DEVICES s

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ENCLOSURE 1 DESCRIPTION OF RELIEF REQUEST The SQN pump and valve in-service test program is contained in the SQN FSAR, section 6.8, appendix 6.8A. Table A of appendix 6.8A lists those pumps that are tested to nwet the ASME Section XI requirements. Each code-required pump parameter is given at the top of tablo A. Where conditions exist that -

preclude the measurement of a specific parameter, a note is provided to explain the basis for relief. Note 2, which addresses the use of ultrasonic flow measurement devices, currently reads:

2. When flow rate is measured with internally installed plant instrumentation, accuracy will be within f?. percent of full scale.

When flow rate is measured with externally mounted ultrasonic transducers, accuracy will be 13 percent of full scalo. -

In order to provide clarification with regard to the use of ultrasonics, note 2 is being revised to state the following:

2. When flow rate is measured with internally installed plant instrumentation, accuracy will be within 12 porcent of full scale.

Certain safety-related pumps at SQN are either not equipped with flow measuring devices or the internally installed plant instrumentation is less accurate than ultrasonic flow devices. The use of ultrasonic flow measurement devices for these pumps during required performance tests would climinate the need for modifications to the systems. The manufacturer's specifications for the accuracy of ultrasonic flow measurement devices aro 1-3 percent, dependent upon flow medium and instrument location. Based on discussions with the manufacturce and TVA laboratory calibration technicians and from previous experieneo in the use of ultrasonic flow devices, TVA anticipatos accurato and repeatable results. The benefits of a possiblo 1-porcont increano in accuracy for an internally installod instrument over the ultrasonic '

device would not warrant the expenses of a plant modification.

Furthermoro, use of externally mounted ultrasonic transducers will preclude the incis'.once of problems inherently associated with an internal Ay installed measurenient device (e.g. , increaso system resistance, flow obstruction, inoperability of system for maintenanco or repair).

TVA will require an accuracy of 13 percent when employing ultrasonic flow devlees. It should be noted that TVA is currently investigating advances in flow measurement technology, which nay provido improvements in flow measurement accuracy.

Attachment A of this enclocuro describes cach relief request in detail and provides the basis for relief. Table 1 of this enclosuro lists the pumps for which rollef is requested to uso ultrasonics as either the primary or secondary means of flow measutomont. This table reflects the flow measurement method that will be uced to meet the requirements of ASME,Section XI. TVA requests colief to employ ultrasonic flow measurement devices with a minimum accuracy of 13 percent in accordance with attachment A.

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.2-Enclosure 2 contains the applicable pages of SQN's FSAR, section 6.8.

Following receipt of either an SER or NRC written concurrence. TVA, in the next FSAR annual update, will amend the applicable FSAR pages to incorporate note 2 as revised.

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ATTACHMENT A i

i I. Safety Injection and Containment Spray Pumps '

A. Code Requirement Article IWP-4110 of the ASME code reautt'ea that instrument accuracy shall be within -2 percent of full scale.

B. Relief Request TVA requests relief from the instrument accuracy requirement of IWP-4110 for flow measut+ ment of SQN's safety injection and containment spray pumps. TVA proposes to use ultrasonic flow measurement devices with a +3-percent full-scale '

accuracy on these pumps.

C. Basis for Relief TVA has procured ultrasonic flow measurement devices for testing the safety injection pumps and the containment spray pumps. The manufacturer's specifications for these devices quote an accuracy of 1-3 percent.

The use of ultrasonic flow measurement devices-for these pumps during required performance tests would eliminate the need for modification to these systems. To ensure a fixed resistance configuration, each safety injection pump must be tested through its own minimum flow line, which .

does not contain a flow measuring device. Each containment spray pump does have flow instrumentation in its fixed resistance configuration however, the aucuracy provided by ,

the plant-installed instrument is less accurate than the ultrasonic flow devices. In order to /

meet code requirements for both pumps, a plant modification would be required to (1) install

• flow instrumentation on the safety injection minimum flow line and (2) change out the current flow instrumentation on the containment spray  :

system to meet a 12 -percent accuracy. The

' benefits of a possible 1-percent inctease in accuracy for an internally installed instrument would not warrant the expense of a plant modification. Furthermore, use of externally mounted ultrasonic transducers will preclude incidence of problems inherently associated with an internally installed flow measurement device (e.g., increase system resistance, flow obstruction, and incperability of system fnr aaintenance or repair).

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2-D. Alternate Testing Table 1 of this enclosure lists ultrasonics as the primary flow device to be used for the SQN safety injection and containment spray pumps. TVA will require an accuracy of 3 percent when employing ultrasonic flow devices.

E. Conclusion TVA has determined that the use of ultrasonic flow measurement devices with a !3-percent accuracy provides an acceptable level of accuracy to determine pump performance / degradation for the SQN safety injection and containment spray pumps. A plant modification to install flow instrumentation that would only provide a 1-percent increase in accuracy over the ultrasonic devices would result in an undue hardship without a compensating increase in the level of quality or safety. For these reasons, TVA finds the code requirement to be impractical and the proposed alternative acceptable.

II. Essential Raw Cooling Water, C uponent Cooling Water, Residual Heat Removal, and Diesel Fuel Oil Transfer Pumps.

A. Code Requirement Article IWP-4110 of the ASME Code requires that instrument accuracy shall be within 12 percent of full scale. .

B. Relief Request TVA requests relief from the instrument accuracy requirement of IWP-4110 for flow measurement of SQN's essential raw cooling water pumps, component cooling water pumps, residual heat removal pumps, and diesel fuel oil transfer pumps. TV proposec ,

to use ultrasonic flow measurement devs..es with 3-percene full-scale accuracy on these pumps.

Ultrasonics would act as backup equipnent, whic' could be used if normal plant flow instrumentat.on is out of service for maintenance or calibration.

C. Basis For Relief TVA has procured ultrasonic flow measurement devices for each of the pumps listed above. The manufacturer's specifications for these devices '

quote an accuracy of 1-3 percent. Plant-installed flow instrumentation is typically used to measure pump flow during required performance tests.

Periodic maintenance and calibration of plant flow instrumentation can result in a delay of a i scheduled pump performance test until the plant instrumentation is returned to service. This may impose an accelerated maintenance or calibration work schedule simply for the purpose of conducting required pump tests. The use of ultrasonics as a s

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1-secondary flow device would reduce this scheduling impact to the plant and allow pump testing to commence as scheduled. This provides a net improvement to plant safety with regard to maintaining test frequency and assessment of pump performance. An additional benefit is provided with regard to planning and scheduling of naintenance activities.

Uncoupling maintenance activities from required pump test schedules will help improve prioritization of work activities directly affecting plant safety by providing alternatives for work items driven only by schedule.

D. Alternative Testing Table 1 of this enclosure lists ultrasonics ss a secondary flow device to be used for the SQN essential raw cooling water pumps, component cooling water pumps, residual heat removal pumps, and diesel fuel oil pumps. TVA will require an accuracy of 13 percent when employing ultrasonic flow devices.

E. Conclusion TVA has determined that the use of ultrasonic flow measurement devices with a 13-percent accuracy provides an acceptable level of accuracy to determine pump performance / degradation for the SQN essential raw ccoling water pumps, component cooling water pumps, rer.idual heat removal pumps, and diesel fuel oil transfer pumps. Ultrasonics would serve as a secondary means of measuring flow if problems are encountered with the plant-installed flow instrumentation. The use of ultrasonics would provide an equivalent degradation detection capability and would improve flexibility fer , scheduling of maintenance end test activities. For these reasons. TVA finas the proposed alternatise to be acceptable.

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TABLE .

PRIHARY SECONDARY JUSTIFICATION pump FLOW DEVICE FLOW DEVICs FOR ULTRA 30NICS Hoto r-driven ultrasonics N/A Tested through auxiliary minimum flow line, feedwater pump (l) which does not contain a flow measuring device.

Turbine-driven ul trasoni cs N/A Tested through auxiliary minimum

• flow line, feedwater pump (l) which does not contain a flow measuring device.

Centrifugal ultrasonics N/A Tested through charging rsep(l) minimum flow line, which does not contain a flow measuring device. .-

Safety injection ultrasonics N/A Tested through pump (2) minimum flow line, which dcas not contain a flow measuring device.

Essential raw FE-67-61 ultrasonics To be used when cooling water FE-67-62 normal plant pomp (3) instruments are unavailable.(4)

Component cooling FI-70-198 ultrasonics To be used when water pump (3) FI-70-200 normal plant FI-70-201 instr;ments are unavailable.(4)

Containment spray ultrasonics FI-72-13 The plant-installed pump (2) FI-72-34 flow instruments are currently less accurate than ultrasonic flow devices.

Residual heat FI-74-12 ultrasonics Ultrasonics wsil be removal pump (3) FI-74-24 used when no mal plant instr *smerts are unavailable.(4)

Diesel fuel oil level indicator eltrasenic; lo be used when transfer pump (3) on the fuel oil normal plant ,

tank instruments are u nav a i l a bl e',' (4)

Bort.c acid FI-63-43 N/A No relief requested.

transfer pump Heat tracing on these pumps precludes use of ultrasonics for measuring flow rate.

Essential raw N/A N/A No relief requested.

cooling water flow measurement not l

traveling screen required.(1) l wash pump (1) Relief requested was previously approved in an NRC SER dated i

January 19. 1988.

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(2) Relief is requested for use of ultrasonic; as a primary flow device l

in accordance with item I of attachment A.

(3) Relief is requested for use of ultrasonics as a secondary flow device l

1 in accordance with item II of attachment A.

s (4) Ultrasonics will only be used in lieu of plant-installed flow instrumentation when problems are encountered with plant instrumentation.

l TVA mainten2 ace and calibration activities will be carried out in a timely l fashion to preclude repeated use of ultrasonics.

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ENCLOSURE 2 APPLICABLs PAGES FROM SQN'S FSAR SUPPORTING RSLIEF REQUEST REGl.RDING ULTRASONIC FLOW MEASUREMENT DEVICES l

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r-SNP-3 APPENDIX 6.8A -

SEQUOYAH PUMP INSERVICE TESTING PROGRAM Summary of Information Provided -

The pump test table (Table A) provides the following information on testing requirements:

1. System 1

2. Drawing on which the pump is depicted -

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3. Speed

4. Inlet Pressure

5. Dif'ferential Pressure

6. Flow Rate

/. Vibration Amplitade

- 8. Observation of Lube Oil Level / Pressure

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9. Bearing Temperature;_

Quarterly testing in accordance with the requirements of Section XI.

Subsection IWP is indicated by "Q", nonconfoer.:ance is addressco in 3 -

specific notes as indicated.

APPENdlX 6.8A reilsed by Amendment 3 6.8A-1

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SEQUOYAH NUCLEAR POWER PLANT Tr.BtE A-PUNP TEST PROGRAM s l Drawing Inlet Differential flow Vibration Bearing Observe Lube Oil I'uT2 Number. Sned Pressurt Pressure Raig Amplitude Temaerature level / Pressure ,

l Notes 12 and 14 hte 15 Notes 2 and 15 Note IE Note 15 Notes 14 and 15 l n pa ap Q V s Ty Auxiliary feed 47W803-2 Note I Q Q Note 13 Q Note 7 Yes Weter (Hotor) I' Auxiliary feeo 47W803 2 Q Q Q Note 13 Q Note 7 Yes t

Water (Steam)

C ntrifugal 47W811-1 Note 1 Q Q Note 13 Q Q Yes Charging 47W809-1 1

l Safety Injection 47W811-1 Note 1 Q Q Note 13 Q Q Yes

System i

Essential Raw 47W845-5 Note I Q. Note 4 Note 4 Note 5 Note 7 Note 3 Cooling Water Note 9 Component Cooling 47W859-1 Note 3 Q Note 4 Note 4 Q Note 6 Yes Residual Heat 47W810-1 Note ! Q, Q Note 13 Q Note 8 Yes 1 Removal i

Diesel fuel Oil 47W840-1 Note 1 Note 10 Note 10 Q. Q Note 7 Note 10 Transfer Note 11 Boric Acid. 47N809-5 Note 1 Q Q Note 13 Q Note 6 Yes Transfer C

ERCW Screen 47W845 5 Note 1 Q. Q Note 16 Note 5 Note 7 Note 3 J Note 9 -

6.8A-2 Revised By Amendment 5 t

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NOTES

1. Synchronous or induction motor driven pumps do not require speed check'per IWP-4400.

2. When flow rate is measured with internally installed plant instrumentation, accuracy will be within i 2% of full scale.

When flow rate is measured with externally mounted ultrasonic $

transducers, accuracy will be i 3% of full scale.

3. This pump uses water lubricated bearings and, thus, lubrication level measurements cannot be taken.

4. These pumps are not equipped with recirculation / test lines.

The nature of the system they feed makes it impossible to specify a particular flowpath that can always be repeated.

Various components which they feed will sometimes require ._

cooling water and sometimes not. Sequoyah established.an 3 in. situ pump curve which establishes the relationship between flow and differential pressure in a band around the pump design point. Subsequent inservice tests compare test data to this curve using the allowable test ranges per IWP-3210.

5. The pump bearings are inaccessible as the pump is submerged in a pit.

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6. These pumps have no installed instrumentation to measure bearing temperature 7.- A bearing cap temperature measurement is not considered indicative of bearing temperature due to temperature gradient caused by operation of space coolers, pump location, etc.

7. Bearings are cooled by pumped fluid, and bearing temperature l measurements are not required per ASME XI.

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8. This is a closed coupled pump and does not have a bearing in 3 the pump and, therefore, does not require bearing temperature measurements per ASME XI.

9'. The inlet pressure is calculated for this pump by measurement of l

lake level.

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SNP-5 NOTES

10. No instrumentation exists to measure inlet or outlet pressure or to determine differential pressure. Differential pressure is not meaningful for detecting degradation of a positive displacement pump. The pump '

bearings are lubricated by the pumped fluid; therefore, lube oil level or pressure is not measured.

11. The only means of measuring flow rate on these pumps is by measuring a level increase in the day tank while the pumps are running. Accuracy using this indirect method of measuring flow rate is poor. Even with poor accuracy, the 10 gpm limit will provide adequate margin for allowing the pumps to fulfill their intended function. Therefore, the 410 gpm limit is being established in lieu of the ranges given in IWP-3100-2.

12. Table IWP-3100-1 requires inlet pressure to be measured both before pump start up and during the test. Measurement before pump startup is -

interpreted as a requirement intended only for pumps which are not_ already in se.rvice prior to testing, e.g., an operating charging pump would not be stopped to record inlet pressure and then restarted to perform test. This measurement only provides indication / verification of adequate NPSH prior to pump start; this indication of pump operational readiness is not applicable for an operating pump.

( 13. Relief has been the system requirested for Article IWP-3100 that requires adjusting resistance. Pumps will be operated in their fixed resistance systems and both differential pressure and flow rate will be compared to reference values as required.

14. Relief gauge.

is requested f rom IWP-4120 to use no lower than a 15 psig pressure

15. Relief is requested f rom IWP-4110 as long as the combined accuracy of IWP-4110 and IWP-4120 are met.

16. No inline instrumentation exists to mea!ure flow and the physical configuration of the pumps and piping does not allow the use of portable flow measuring equipment such as ultrasonics. Additionally, a minimum discharge pressure has been specified thus ensuring adequate flow to the spray nozzles.

5 The 1974 ASME Section XI Code does not require the measurement of both aP & flow for fixed resistance system. Table A shows unit 2 testing criteria which requires measurement of both AP & flow unit 1 does not require this.

6.8A-4

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