ML17055C658

Summary of 861015 Meeting W/Utils & S&W Re MSIVs Leakage Problems.Hydraulic Cylinders on Modified MSIV Actuators Not safety-related.Util Requested to Perform Addl Leak Test

ML17055C658
Person / Time
Site:	Nine Mile Point
Issue date:	11/20/1986
From:	Haughey M Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8612020158
Download: ML17055C658 (92)

Text

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4vg November 20, 1986 Docket No. 50-410 FACILITY:

Nine Mile Point Nuclear Station Unit 2 (NMP-2)

APPLICANT:

Niagara Mohawk Power Corporation (NMPC)

SUMMARY

OF OCTOBER 15, 1986, MEETING 'HITH NMPC ON MAIN STEAM ISOLATION VALVES FOR NMP-2 On October 15, 1986, the NRC staff met with representatives of Niagara Mohawk Power Corporation (NMPC) and their consultants to discuss concerns related to

'he main steam isolation valves (MSIVs) for NMP-2.

Handouts provided by NMPC at the meeting are included as enclosures 1 and 2.

NMPC presented their conclusions of their investigation of the root cause of recently identified leakage problems of the MSIVs.

The root cause was identi-fied as a rocking and friction problem which occurred when the valve was in the partially open position.

The spring arrangement in the valve seats would be modified to correct the rocking problem in the partially open position there-by eliminating the resultant galling problem on the valve balls.'he galling had resulted in excessive valve leakage.

NMPC stated their certainty that this was the root cause.

NMPC stated that four MSIV balls would be repaired, installed and leak tested by October 26, 1986.

Leak testing, as required by 10 CFR 50, Appendix J, would be performed between the seats with a leakage criteria of 6 SCFH.

NMPC stated the final deficiency reports in accordance with 10 CFR 50.55e would be filed October 22, 1986.

Those reports were to include information presented during the mee'ting.

NRC questioned NMPC on the possibility of vortex shedding of the MSIVs.

NMPC stated that this phenomena had.not been reviewed and would be difficult to determine.

NMPC stated that 36 days were scheduled between fuel load and the beginning of the power ascension program which was scheduled for early December.

All of the MSIV balls would need to be installed by the end of November to not affect the schedule for criticality.

Actuator installation and testing was scheduled to take 3 days for each valve.

Commercial power is scheduled for June 30, 1987.

The hydraulic cylinders on the modified MSIV actuators are not considered by NMPC to be safety related.

Except for the added lip seal the cylinders are the same as those on the original actuator design.

Because of the importance of the prototype tesing proposed by NMPC to confirm the adequacy of the NMP-2 MSIVs, the NRC requested NMPC to submit the objectives of the prototype testing, the schedule for the testing and a commitment to submit the results of the testing to the NRC.

The NRC stated that these items would be included in a license condition.

In addition, the NRC requested NMPC to commit to perform an additional leak test 8612020158 861120 PDR ADQCK 05000410 8

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Mr. C. V. Mangan Niagara Mohawk Power Corporation

.Nine Mile Point Nuclear Station Unit 2 CC:

Mr. Troy B. Conner, Jr.,

Esq.

Conner 5 Wetterhahn Suite 1050 1747 Pennsylvania

Avenue, N.W.

Washington, D.C.

20006 Richard Goldsmith Syracuse University College of Law E. I. White Hall Campus

Syracuse, New York 12223 Ezra I. Bialik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2 World Trade Center New York, New York 10047 Resident Inspector Nine Mile Point Nuclear Power Station P. 0.

Box 99 Lycoming, New York 13093 Mr. John W. Keib, Esq.

Niagara Mohawk Power Corporation 300 Erie Boulevard West

Syracuse, New York 13202 Mr. James Linville U. S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Norman Rademacher, Licensing Niagara Mohawk Power Corporation 300 Erie Boulevard West

Syracuse, New York 13202 Don Hill Niagara Mohawk Power Corporation Suite 550 4520 East West Highway

Bethesda, Maryland 20814 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Mr. Paul D. Eddy New York State Public Serice Commission Nine Mile Point Nuclear Station-Unit II P.O.

Box 63

Lycoming, New York 13093 Mr. Richard M. Kessel Chair and Executive Director State Consumer Protection Board 99 Washington Avenue

Albany, New York 12210

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of the MSIVs in accordance with the test and acceptance criteria in 10 CFR 50, Appendix J during the first outage following the 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> warranty run or within 30 days following the 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> warranty run, whichever is earlier.

A list of, meeting attendees is included as enclosure 3.

Enclosures:

cc See next page Mary F. Haughey, Project Manager BWR Project Directorate No.

3 Division of BWR Licensing BWD-3:DB MHaughey/vag 11/])/86 D:BWO-EAdensarq,

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November 20, 1986 MEETING

SUMMARY

DISTRIBUTION 4.Docket No(s):

50-41~0 NRC PDR Local PDR BWD 83 r/f J. Partlow E.

Adensam

Attorney, OGC E. Jordan B. Grimes ACRS (10)

Project Manager E. Hylton NRC PARTICIPANTS M. Haughey Jack Kudr ick Frank Witt Wayne Hodges E.

G.

Adensam J.

C. Linville R. A. Hermann R.

G. LaGrange J.

Lombardo bcc:

Applicant 8 Service List

A l'f II i

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10/15 86 MEETING-MSIVs Enclosure 3

NAP 1E Mary F. Haughey Jack Kudrick Frank Witt Wayne Hodges E.

G. Adensam J.

C. Linville R. A. Hermann R. G. LaGrange J.

Lombardo T. Wang P. Teperou Warren Wang A. F. Zallnick C. E. Crocker D. A. Boe C.

G. Beckham J.

P.

Thomas A. Fiorente T. D. Fay R. A. Cushman J.

C. Hutton E.

R. Klein R. B. Abbott D. L. Pike John E. Arthur T. J. Perkins A. E. Kintigh M. A. Durka W. D. Donlon Wm. R. Schmidt ORGANIZATION NRC - Licensing Project Manager NRC/DBL/PSB NRC/DBL/PSB NRC/DBL/RSB NRC/DBL/BWD-3 NRC/RI/DRP NRC/DBL/EB NRC/DBL/EB NRC/DBL/EB Stone 5 Webster Stone 5 Webster Stone 5 Webster NMPC - Licensing SWEC - Engr.

SWEC - Engr.

NMPC Duquesne Light Co.

SWEC - Engr.

NMPC - Licensing NMPC - Licensing Rochester Gas and Elec.

NMPC NMPC NMPC Rochester Gas and Electric NMPC NYSEG SWEC NMPC MPR Associates, Inc

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MSIV LONG TERM PROGRAM OBJECTIVES CONFIRM FAILURE MECHANISMS REVIEW EXISTING DESIGN/MATERIALS FULL SCALE PROTOTYPE TESTING DESIGN/MATERIAL ENHANCEMENTS DEMONSTRATE LONG TERM OPERABILITY

I II'

Niagara Mohawk Power Corporation Nine Mile Point Unit 2 MSIV Program NMPC Program Manager C. Terry Short Term Program E. Klein Long Term Program J.. Hutt'on Contingency Plans D. Pike

~D.

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< Site Contact o Liaison with,short term activities Stone 8c Webster Crosby General Electric WestinghoUse Consul tant Specific tasks o Vendor Representative o Specific tasks o.Project Manager o Consultant o

Task definitions o Specific tasks

'o Specific tasks o Technical Review o Periodic status reports o Final report o Consultant o Specific tasks

I

'I I

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MSIV LONG TERM PROGRAM GENERAL DESCRIPTION PHASE 1

FAILURE ANALYSIS OPERATIONAL EXPERIENCE VALVE/ACTUATOR DESIGN REVIEW EVALUATE BALL/SEAT MATERIALS INITIALPROTOTYPE TESTING o

PHASE 2

IDENTIFY DESIGN ENHANCEMENTS SELECT MATERIAL CHANGES PROTOTYPE TESTING o

PHASE 3

DETAILED MODIFICATION DESIGN DESIGN VERIFICATION TESTING MATERIAL PROCUREMENT INSTALLATION/PREOP TESTING

)

MSIV LONG TERM PROGRAM PRELIMINARY SCHEDULE PHASE 1 REVIEWS OCT '86 JAN '87 INITIALPROTOTYPE TESTING FEB '7 MAR '7 SELECT ENHANCEMENTS APR v 87 JUN e 87 TEST ENHANCEMENTS JUL '7 DEC '7 FINALIZE DESIGNS JAN '8 MAR '8 DESIGN VERIFICATION APR 188 DEC '88 PROCURE MATERIALS MAR '88 4

REPUELING OUTAGE MAR s 89

I I

MSIV LONG TERM PROGRAM PROTOTYPE TESTING SCHEDULE 10/86 Procure Valve X

10/86 Procure Actuator X

X 12/86 Assemble 1/87 Installation 2/87 Initial Testing 3/87 X

X X

Identify 10/86 Test Facility X

11/86 Prepare Test Facility X

X 10/86 Test Plan/Spec 11/86 Assemble Instrumentation X

X X

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MSIV BALL VALVES:

NRC MEETING OCTOBER 15, 1986 AGENDA BACKGROUND...,,,,.........,...,...,....,.

C.D.

TERRY 4'VERVIEW...,...,.

~..,...,...,,.. ~,

~..,.

~.,, C.D.

TERRY

~ RESOLUTION OF LEAKAGE PROBLEMS,...

E.R.

KLEIN

,~. ACTUATOR MODIFICATIONS....,....,...

E.R.

KLEIN LONG RANGE PROGRAMS.................

J.

HUTTQN

~ CONCLUSIONS.....,.................,......

C.D.

TERRY NMMSIVMP29

l

BACKGROUND

~ ACTUATOR PROBLEMS DISCOVERED EARLY AUGUST

~ LEAKAGE PROBLEMS DISCOVERED LATE AUGUST

~ INTERIM MEETING WITH NRC SEPTEMBER 24

~ IN T E RIM 10C 7 R50.55(e)

PEP OR T LEAKAGE PROBLEMS OCTOBER 8

QVERVIE W RESOLUTION OF LEAKAGE. PROBLEMS TESTING/ANALYSIS OF PROBLEMS ROOT CAUSE DETERMINATION EVALUATION OF OPERATING CONDITIONS STATUS OF REPAIRS

~ ACTUATOR MODIFICATIONS DESCRIPTION CONFIRMATORY TESTS SCHEDUlE

~ LONG RANGE PROGRAMS PROGRAM DESCRIPTION SCHEDULE/STATUS

~ CONCL US ION

I II RESOLUTION OF LEAKAGE PROBLEMS REVIEW OF PREVIOuS DATA REVIEW OF IN PLANT TEST DATA 4 MATHMATICALANALYSIS e TESTING SITE RESULTS LABORATORY RESULTS METALLURGICAL CONCLUSIONS

~ SCHEDULE NMMSIVMP44

MSIV SEAL ARRANGEMENT DE T AIL "A" VALVE BODY SEAL ASSEMBLY SEAL SEAT 7.2 IN SPOOL/'SEAT MOMENT ARM ENCAPSULATED SPRINGS SPRING RETAINER MULTIPLE SPOOL SEALS SEAL RING SPRING COVER BALL SURFACE BALL

. NMMSIVMD24 BALL Bc SEAT ASSEMBLY IN THE CLOSED POSITION FIGURE 4-2

MODIFIED SPRING CONFIGURATION 24-t15II SPRINGS s->>sN SPRINCS a S-Sv.sk SPRINGS o->nS SPRINGS REMOVKO 24->>58 SPRINGS'OTAL SPRLNG LOAD 56 1158 SPRINGS = 64408'

-S75III SPRINGS =

4600 69OO

BALL I

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/

/

/

8ALL ROTATI

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RESULTANT F Rl C T I ON FORCE

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I CONTACT AREA SEAT ROTATION RE AC TION I 0 FRICTION FORCE PACKING NMMSIVM057 47 VALVE OPENING FRICTION FORCE 8c. ROTATION

~

ACCUMULATED CYCLES NEW BALL MODIFIED SPRINGS BLENDED BALL ORIGINAL SPRINGS BLENDED BAI L MODIFIED SPRINGS BS TS BS4

=BS TS 4.8 2.3 11.2 5

~

1 18,4 4.9 2.9 51 5.5 25 4, 7

10. 9 1 00+

4 4

45 4.2 65

3. 9 4

4 2

NOTES:

BETWEEN SEATS SCFH THROUGH SEATS SCFH 0 4 0 THROUGH SEAT TESTING NOT COMPLETED DUE TO POOR INITIAL TYPE

'C BETWEEN SEAT TESTING.

NMMSIVMD52 TEST LEAKAGE

SUMMARY

TABLE 4-3

BLENDED BALL MODIFIED SPRINGS 6" Blended Area

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I 10500'1.00 SEAT of.<

6n Ggf<~

ML )

MR A2 A

SPOOL/'SEAT ROCK

SPOOL 1

SEAT MODEL BALANCED SPRINGS 2,553 3,450 3,450 2,553

~2'+

WP,

%PR QPx a =

M, 0PR x

b =

MR M, M = 17,066 (Ib in) 17,066 7.2 2,370 (Ib) 2,370 6,900 x 0.74

0. 46

SPOOL i SEAT MODEL MODIFIED SPRINGS 3,450 3,450 2,553 NP QPR b,

ML= (NPx a)(F, x a,)

M,= (QPRx b)+(F, x b)

M, M = 27,182 (Ibin) 27,182 7.2

= Z,775 (ib) 3,775 6,900 x 0.74 0.74

SPOOL

%SEAT MODEL MCOIFIED SPRINGS x = 6.193

7. 492 a = 1.03 22.11 INCHES 152 c = 11.621 M

= 6.900 x P x.74 x MOMENT ARM FR M

= 12,867 in-Ib FR d ~ 18.605 2,530 2,530 920 920 MFR Y

%MA =

0 920a + 2,530b + 2,530d + M~R=RIc.

R

=

1 R1-Y =

6,870 LB

-'X 2,219

~lb 2,219 x.74 2 x.3125 6'

2,627 PSI

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FQOTPRlNT STRESS ON BALL IIIIII IIIIII II BALL VALVE OPEN FOOTPRINT STRE55 QIACRA4l

4. BALL FOOTPRINT STRESS OIACRhM

FOOTPRINT STRESS ON BALL IIIIIII IIIIIIIII BALL VALVE OPEN BALL VALVE AT Q I

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C4 O

I FOOTPRINT STRESS DIAGRAM 4 BALL FOOTPRINT STRESS DIAGRAM 6.9 x.74 46.4 Ksi 2 x.055

II

NMMSIVMD71 STEAM FLOW VALVE FULLY OPEN F1QURE 5-3

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VALVE CLOSING DIRECTION CONTACT STRESS 560 PSI STEAM I

I FLOW 16'

/

DIRECT IMPINGEMENT 21

~ 7 KIPS VALVE PARTIALLY CLOSED

T I

HANDLE BALL TRUNNION BALL SUPPORT CRADLE TIMBERS HYDRAULIC C YLINDER RAM HEAD STELLITE 6 HARDFACE C.S.

PLATE 1"

~/g'8 3"5 C.S.

PIPE C.S. PLATE 1"/4'MLISIVMD54 MOCK UP FRICTION TEST

0 I

56,000 PSI BALL PRESSURE SEAT AljtEA.06 IN So.

TEMPERATuRE 450 F

NUMBER OF STROKES MSIV BALL SURFACE SIMULATED SEAT l0 DARKENED CONTACT AREA, SLIGHT SEAR POLISHING 20 VISIBLE WEAR, SOME TRANSFER OF MATERIAL VISIBLE WEAR 30 SME ARING, POCK MARKS GRAINY SURFACE APPEARANCE POCKMARKS SCRATCHES MORE WEAR, SIGNS OF FRACTURE CRACKS ACROSS WEAR SURFACE, LAYFRED TEXTURE TO SURFACE MORE WEAR MATERIAL REMOVED 50 WC FAILURE COATING FLAKEO OFF MORE WEAR NMMSIVllP33

3,500 PSI BALL PRESSURE SEAT AREA.D6 IN SO*

TEMPERATURE 65 F

NUMBER OF STROKES MSlV BALL SURFACE SlMULATED SEAT NO WEAR BLACK LINE INDICATING CONTACT AREA NO WEAR CONTACT AREA POLISHED 45 NO CHANGE NO CHANGE NO CHANGE VISIBLE WE AR SCRATCHES & PIT TING 125 ROUGHER SURFACE SHINY AREAS POSSIBLE TRANSFER OF SEAT MATERIAL TO THE BALL WEAR HAS INCREASED WEAR ON SEAT HAS SLOWED DOWN 225 WEAR RATE HAS SLOWED DOWN AMOUNT OF WEAR WOULD REOUIRE RELAPPING OF THE WC COATING SAME AS ABOVE NMMSIVMP32

I

LOAD APPLIED THROUGH HYDRAULIC ACTUATION A-A ROTATES 90 50 FPM VERTICAL MOVEMENT FIXED PLATE OF TEST MATERIAL NMMSIVMD55 UNION CARBIDE WEAR TEST MACHINE

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I

SUMMARY

COEFFICIENT OF FRICTION 0 REQUIRED TO INITIATE ROCKING BALANCE D SPRINGS 0 UNION CARBIDE TEST RESULTS' THEREFORE, "ROCKING" OCCURS-BALANCED SPRINGS e REQUIRED TO INITIATE ROCKING MODIFIED SPRINGS c THEREFORE, ROCKING" WILL NOT OC C UR MODIF IE D SP RINGS NIMSIYLIP45

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~ FAILURE MECHANISM OF TUNGSTEN CARBIDE COATING

~

DURING INITIAL BALL CYCLES STELLITE FROM SEAT DEPOSITS ON CARBIDE COATING

~

AT HIGH LOADS AND ADDITIONAL CYCLES, STELLITE ON SEAT COLD

%ELDS TO STELLITE PREVIOUSLY DEPOSITED QN BALL NITH CONTINUED CYCLING, TUNGSTEN CARBIDE COATING SPALLS FROM ITS LOCATION ON BALL NMMSIVMP41

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ATTR18UTE NEN BALL RECOATED BALL BALL MATERIAL 316 SS CASTING ORIGINAL CASTING USED EXTENSIVE SELD REPAIRS MINOR ADDITIONAL WELD REPAIRS SOL'N ANNEAL AFTER REPAIRS NO SOL'N ANNEAL AFTER REPAIRS HARDFACING MATERIAL HAYNES 25 BY SAW NELD REPAIRS BY GTAW NO HEAT TREATMENT

.080.TO.100 FINAL THICKNESS FINAL SURFACE GROUND FINAL PT ORIGINAL DEPOSIT USED WELD REPAIRS BY GTAW NO HEAT TREATMENT

.076 TO.097 FINAL THICKNESS FINAL SURFACE GROUND FINAL PT TUNGSTEN CARBIDE COATING MATERIAL APPLIED BY UNION CARBIDE SURFACE PREP BY BLASTING APPLIED BY 0-GUN 0.010 MIN THICKNESS FINAL SURFACE GROUND LAPPED TO SEAT IN SHOP LAPPED TO SEAT IN FIELD APPLIED BY UNION CARBIDE SURFACE PREP BY BLASTING APPLIED BY D-GUN 0.010 MIN THICKNESS FINAL SURFACE GROUND LAPPED TO SEAT IN SHOP HMMSIVMPS6

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SCHEDULE OF REPAIRS SERIAL NUMBER COATING REMOVED SURFACE COATING PREPARATION REAPPLIED SEAT LAPPING AT SITE 10r 15t A) 10r i6t S) lor20t 5) 10r 22t S) 6 10i25(S) 7

)Or 29(S)

,)or 31tS)

HMMSIVMP43 10r 27tS)

0

~

e

~

REPLACED ITEMS:

CYLINDER NEW:

PRESS SWITCHES ACCUMULATOR JOCKEY PUMP 2 8 MSIV CONVERTED HYDRAULlC SYSTEM 2 8 HYDRAULIC ACCUMULATOR RESV SOLENOID VALVES s

2 sov

[sS-

/g sov Qs 2" sov RV SET I 1500 PSI

% TRAi~'ER 1~/4" m 1/4 8 JOCKEY MOTOR PUMP 24'STROKE 14 BORE 2'/"

C YLINDER 1500 PSI PT 2 8 HOSE FIL TER PS (2)

~/g"8 CHECI<

VALVL-PUMP 3 GPM 1500 PSI I ~

MOTOR t

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HYDROLINE HYDRAULIC CYLINDER CYLINDER TUBE CYLINDER HEAD rII II III TRUNNION I

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'll\\l WEAR BAN ROD SEAL 0-RING RETAINER ROD WIPER PISTON ROD WEAR BAND LIP SEAL WEAR BAND CYLINDER HEAD CAP 0-RING lAECHAMCAL STOP ll I

I

~a~

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III1I/

I TIE RODS TRUNNION ASSEllBLY

~

~

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e HYDR'AULIC CYLINDER ENHANCEMENT e

MODIFY THE EXISTING CYLINDER DESIGN ADDED MECHANICAL STOP TO ESTABLISH

~ F ULL OPEN POSITION

~ ADDED LIP SEAL TO PISTON FOR LEAKAGE CONTROL

~

PROOF TESTING OF HYDRAULIC CYLINDER

~ HYDRO TEST TO 2250 PSI

~ CYCLE 100 TIMES FOR BREAKIN

~ CYCLE 5

TIMES UNDER LOAD MAINTAINING 1500 PS I

~ PRESSURIZE CYLINDER AND MEASURE LEAKAGE 112 C UBIC INCH P E R MINUTE

~ ISSUE TEST REPORT

~ S V/E C P 0 A Vf I T N E S S T E S T S

~t

~

~

4.50 DIA PRESSURE BALANCED SOLENOID OPERATED VALVE 20.00'ISTON 3.38" DIA 10.00'0.50"

L

~

~ '

s I

OR I G IN A L MODIF IE D EP RUBBER 0-RING GRAPHITE FILLED TEFLON BACKUP RING EP RUBBER 0-RING NMMSIVMD85

~ >

I c

~

~

I t ~

E SOV MODIFICATIONS TEST RESULTS INDICATED EXISTING 'O'RING NOT SUITABLE

'O'RING VfEDGED AT PRESSURE

~ DELAY IN ACTUATION AT PRESSURE.

~

ADDITIONAL MATERIALS TESTED

~ TEF L.ON

~ RADIATION CONCERN

~ MECHANICAl STABILITY CONCERN

~ TEFZEL

~ TOO HIGH COEFF ICIENT QF FRICTION

+ GRAPHITE FILLED TEFLON

~ ENVIRONMENTALLY QUALIFIED FOR

> 25 YRS

~ NO DELAY IN ACTUATION

~t s

~

s

TESTING RESULTS CYCLE TIMES 20 HOURS

~

LEAKAGE

~ SOV

~ UNDETECTABLE

~ HYDRAUL)C C YLlNDER o

c lt'2 CU. )N. PER M)N o

RESPONSE

TIME.

~ SOV TR)P W)TH)N.5 SEC.

e M5)V CLOSES W)TH)N 3 TO 5 SEC.

CLOSURE REQUIREMENT HMMSIVQP38

gk

~

I

TARGET SCHEDULE ADD IT ION AL EQUIPMENT ON SI T E NEI HYDRAULIC C YLINDER 10i15 NEN SEALS FOR SOV INSTALL EQUIPMENT 10 i'15 10i15 10'1 TESTING 10/'21 11' MSIV'S ACTUATORS COMPLETE NMM5IVMP39

si

~

~

CONCLUSION LEAKAGE PROBLEMS

~

SUFFICIENT UNDERSTANDING OF ROOT CAUSE TO DEVELOP FIX FOR OPERATING CYCLE

~

ANALYSIS OF OPERATING CONDITIONS DO NOT ADD SIGNIFICANTLY TO SEAT "ROCKING" PROTOTYPE TESTING WILL CONFIRM ANALYSES OR IDENTIFY PROBLEMS EARLY IN OPERATING CYCLE MIDCYCLE

'TYPE C" TESTING PROVIDES ADDITIONAL ASSURANCE

~

FINAL FIX TO BE THOROUGHLY DEVELOPED AND TESTED BEFORE FIRST REFUELING OUTAGE

~

DESIGN AND PROCUREMENT FOR CONTINGENCY PROGRAMS CONTINUES ON AN EXPEDITED BASIS

t w

4

CONCLUSION ACTUATOR MODIFICATIONS o FIRST CYCLE FIX MODIFICATION OF HYDRAULIC SYSTEM ACCEPTABLE MATERIALS VERIFICATION TESTING IN SHOP PRELIMINARY AND START UP TESTING %ILL COMPLETELY VERIFY OPERABILITY

~ MECHANICAL LATCH BEING DEVELOPED AS PART OF LONG RANGE PROGRAM

I

Docket No. 50-410 NOV 18 1986 MEMORANDUM FOR:

Elinor G. Adensam, Director BWR Project Directorate No.

3 Division of BWR Licensing DISTRIBUTION:

',~N.

50-410 PSB r/f MHaughey FROM:

SUBJECT:

Gus Lainas, Assistant Director Division of BWR Licensing NINE MILE POINT UNIT 2 SEQUENCE CHANGE IN REFURBISHING MSIVS (TAC 8 63454)

In Supplement 5 to the SER dated October

1986, we stated that the four main steam isolation valves (MSIVs), with modified seat spring configuations and recoated tungsten carbide balls, used for secondary containment integrity prior to criticality wi 11 have deactivated, unmodified actuators.

The licensee, in letters dated November 11 and 17,

1986, now proposes to remove the actuators from the MSIVs which are being used to isolate secondary containment, in order to begin modifications to these actuators while secondary containment is still required.

Upon completion of the modifications the actuators will be reinstalled on the valve bodies.

The MSIVs will remain in the closed position during the entire time that the actuators are being removed, modified, and reinstalled.

Also, inadvertent ball movement is not expected while the actuators are not in place because of the high seat spring force on the ball and the large torque required to rotate the ball.

The torque needed to rotate the ball is estimated by the licensee to be a minimum of 50,000 in-lb.

We, therefore, have reasonable assurance that the MSIVs will remain in the closed position, thereby maintaining secondary containment integrity during actuator removal, modifications, and reinstallation.

Our SALP is enclosed.

Enclosure:

As stated cc:

R. Houston J.

Calvo J.

Mulhoun R. Bosnak M. Haughey T. Collins Gus Lainas, Assistant Director Division of BWR Licensing

Contact:

F. J. Witt, NRR X29440

• SEE PREVIOUS CONCURRE PAGE PSB

• SL:PSB

• B B

FJWitt/hmc JKudri ck L

man 11/17/86 11/18/86 1.1/IE/86 SL:RSKkP AD R:DDL TCo1 1 ins GL s

11/18 /86 11ir

/86

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SALP INPUT FROM THE PLANT SYSTEMS BRANCH FOR NINE MILE POINT, UNIT 2 TAC 863454 A.

Licensing Activites 1.

Management Involvement in Assuring equality During the review process, there was early evidence of valve problems at another plant.

Management involvement should have prevented the issue from occurring, or occurring so late in the licensing process by getting involved early to fix the problem.

Rating:

3 2.

Approach to Resolution of Technical Issues from a Safety Standpoint Timely resolution of issues was experienced during conference calls with knowledgeable applicant personnel.

Rating:

2 Responsiveness to NRC Initiatives:

Applicant provided technically sound and thorough responses and timely resolution of issues.

Rating:

I 4.

Staffing (Including Management)

Rating:

N/A 5.

Reporting and Analysis of Reportable Events.

Rating:

N/A 6.

Training and qualification Effectiveness.

Rating:

N/A 7.

Overall Rating for Licensing Activity Functional Area.

Rating:

2

'I P

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