ML20151V856

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Forwards Final Rept in Response to IE Bulletin 85-003, Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings. Rept Provides Verification & Summaries Requested Under Item F of Bulletin
ML20151V856
Person / Time
Site: Beaver Valley
Issue date: 04/18/1988
From: Sieber J
DUQUESNE LIGHT CO.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-85-003, IEB-85-3, NUDOCS 8805030216
Download: ML20151V856 (15)


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'Af Te4pnone '41!) 3934000 Nuclear Group sr $g*p' ort, PA15077 6 bpI11 1O 7< 19bO U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 IE Bulletin No. 85-03; Motor Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings, Final Report Gentlemen:

Please find attached the final report in response to IE Bulletin 85-03. The report provides the verification and summaries requested under Item f of the Bulletin. ,

If you have any questions regarding this submittal, please contact me or members of my staff.

4 Very truly yours, eber Vice President Nuclear Group l

Attachment i

-cc: Mr. J. Beall, Sr. Resident Inspector Mr. W. T. Russell, NRC Region I Administrator '

Mr. P. Tam, Project Manager  :

Director, Safety Evaluation & Control (VEPCO) i l

l 9805030216 880418 " dl PDR G

ADOCK 05000334 PDR j.E ,

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COMMONWEALTH OF PENNSYLVANIA)

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COUNTY OF BEAVER )

On this [f)Y/[, day of M4i/> , 1988, before me, 6L 1/J. N8A/ff/ , a Notaryl Public in and for said <

Commonwealth and County, personally appeared J. D. Sieber, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.

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IE BULLETIN 85-03 FINAL REPORT Background Correspondence In response to IE Bulletin e5-03, Duquesne Light Company (DLCo) submitted the initial report, dated May 16, 1986, on the Beaver Valley Power Station, Unit No. 1 (BVPS-1) IEB 85-03 program objectives. In addition, by letter dated September 25, 1987, we provided the BVPS-1 and 2 responses to the office of Nuclear Reactor Regulation's (NRR) Request for Additional Information. By letter dated February 10, 1988, a submittal date extension for the final report was requested. Please find below the final report in response to Item f of the Bulletin.

1. Provide verification of completion of the requested program.

Response

our initial report verified maximum design differential pressures to size motor operators for ECCS related valves required to open or close to mitigate the consequences of an accident. Table 1 summarizes the results of that evaluation.

The second commitment in our initial report was to prepare / modify the BVPS-1 electrical maintenance procedures to formally control torque switch setpoint changes on all motor operated valves.

Maintenance Procedure CMP-1-75-VALVoP-lE was revised to require recording "as found" and "as left" torque switch setpoints and modified to include an acceptable torque switch setpoint range. The minimum setpoint corresponding to the nominal seating thrust and the maximum torque switch setpoint is the operator limiter plate setting. In addition, engineering concurrence is required for safety related MOV torque switch changes, j The final commitment in our initial report was to calculate required motor operator seating thrust, stroke time, current draw, and opening torque switch bypass limit, and then verify these parameters by direct measurement using the MOVATS measurement technique. A second Electrical Maintenance Procedure, CMP-1-75-MOVATS-lE was adopted at BVPS-1 to control the use of the MOVATS instrument and its output data. This program has also been completed as indicated below.

2. Provide a summary of the findings as to valve operability prior to any adjustments as a result of this bulletin, and
3. A summary of data in accordance with Table 2, suggested Data Summary Report.

Response

The nominal seating thrust for each MOV identified for this evaluation was calculated using an Industry Standard Calculation described in Attachment 1. The seating force for each valve was calculated using this Industry Standard Calculation and the maximum

IE Bulletin 85-03 Final Report Page 2, design basis differential pressure identified in Table 1. This calculated thrust was then verified by comparison with the original motor operator design parameters from Limitorque. In all cases, the design seating thrusts of the valves were previously determined by the valve manufacturers. Limitorque then determined the operator size (torque) required to produce the seating thrust, Lim 1 torque also determined the gear ratio required to meet the speci.fied stroke time requirements. -The motor operator sizes (stall torques) were confirmed using conservative stem friction factors and gear ratios identified by Limitorque.

A summary of the seating thrusts calculated by DLCo compar6d to the valve / operator manufacturer's calculated thrusts, is shown on Table 2.

The thrusts calculated by DLCo and the valve / operator suppliers show good agreement for all valves except for 3" Velan Gate Valve applications.

The thrust range bounded by the values calculated by DLCo and the valve manufacturer was used as the "target" nominal seat thrust range for the respective valve except for the Velan 3" Gate Valves. The higher thrust calculated by DLCo was used as the minimum target thrust for these valves. In addition, a 10% to 20% tolerance above these nominal thrusts was permitted to account for instrument tolerances and to provide additional margin wnen the performance of the valve operators was verified, using the MOVATS procedure. The calculated thrust differences resulted from differing calculation i assumptions for the original plant operator designs, i Table 2 indicates that MOVATS measured "as left" thrusts are within or exceed the calculated maximum differential pressure seating thrust range for all valves except MOV-CH-310. The anomaly for MOV-CH-310 was due to a low torque limiter setting of 2.0. The correct limiter setting was subsequently confirmed by Limitorque to be 3.0.

Consequently, this MOV will be set within the calculated thrust range by slightly increasing the torque switch set point.

The functional performance of MOV-CH-310 is not degraded since:

  • The "as found" thrust levels were not reduced during the MOVATS testing

. The valva receives an automatic signal to close during SI  !

actuation and has operated (closed) satisfactorily during past BVPS W1 operation.

  • The charging pump characteristic output parameters are 5 to 10%

less than the maximum differential pressure design condition and are consistent with the calculated and measured thrust values for this valve.

IE Bulletin 85-03 Final-Report Page 3, l i

i Table 2 indicates that the "as left" torque switch setpoints are less i than the maximum limiter setting; the set-points slightly below the torque switch lower limit corresponds to thrusts which are within or greater than the nominal seating thrust range. The torque switch 1 bypass in the opening (unseating) direction was confirmed by MOVATS l Testing to be set to open at 20% to 25% of the valve stroke, so l maximum operator "pullout" thrust is available to open a valve wedge  :

past the point where differential pressure drag is significant.

Valve stroke times and current draws were measured with the MOVATS procedure and determined to be acceptable.

A comparison of "as left" seating thrust and MOVATS database [

differential pressure thrust is also included in Table 2. This  :

comparison data and the measured thrust data indicate that the  !

valves in this evaluation are set at thrust levels which assure cycling operability because at least one of the following conditions ,

exist:

t

! (1) MOVATS verified "as left' thrust levels are within or exceed the  !

maximum differential pressure calculated thrust range.

(2) MOVATS verified "as left" tarust levels exceed the MOVATS thrust data base level.

(3) The valves are normally closed and can be unseated (opened) with maximum available operator pullout thrust, verified by torque  !

switch bypass limit settings, set and confirmed by MOVATS test ;

data.

i I (4) The valves are normally open with an "open" safety position. l (5) Safety function valve operability has been demonstrated at comparable thrust levels during previous plant operation (i.e.,

valve CH-310).

l 1 Motor operated valves at locations CH-289, CH-115C,E, and CH-373, are l set at thrust levels within or exceeding the calculated thrust range. Since these valves are normally open, DLCo will review their i torque switch setpoints in accordance with the MOVATS database

. closing thrust levels, and increase them if necessary to provide j greater closing operability assurance.

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1 TARLT 1 (A) iB) (C) (D) (E) (F) (C) (H) valve Design S pc. Normal Operates on Emergency Accident .

Valve System (Basis)A P System Safety System Function VT1ve Operator Function hen /Close operation Signal Ope ra t ion gP) Psi Syrten location Manufacturer, no. Componer.t Model, I D, Manufacterer, Motor RPM, Type, Sire, ANSI hting

1) C::-1158, D Limitorque RwST to 200/200 Closed Yes Open 40 (1) 8-CM42FB SMR-DO-10 Charging A. Darling Cate 3600 RPM Pump Suction G", 150 psi
2) CC-275 A, B, C Limitorque Charging 2750/2750 Open No (operation Closed 2,550 (1) 2-TM58 FN SMM-OO-25 Pump from Benchboard)

Velcn 1800 RPM Mini-flow Clote Isolation 2", 1500 psi

3) CM-115C, E Limitorque VCT 200/200 Open No. (close on closed 40 (1)
  • 4-CM42FB SMB-OO-5 Outlet signal when Anchor-Darling 3600 RPM CH-115 B&D are

, 150 psf *P'"I

4) CH-350 LimitorqJe Emergency 200/200 Closed No - (Operation Open 40 (1) 2-CM42rs SMB-OOO-5 Boration from Benchboard)

Aloyco 1800 RPM Isolation Gate 2", 150 psi 51 CJ-289 Limitorque Charging 2750/2750 Opan Yes closed 2750 (1) 3-CM58FN SMB-OO-15 Containment Yelen 1800 RPM Isolation Cr.t e 3", 1500 psi

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. _ - - - . - - - . . . - . . - - .- -_ .-= - ~ - . , - . . - _ . ~ = . . .. . ., -- - .- . . . - - - = --

R TABLE 1 (A) (B) (C) (D) (E) (F) (G) (N)

Valve Design Spec. Normal Operates on Emergency Accident Valve System (Basis)A P System Safety System Function valve Operator Function Open/Close Operation Sitsal Operation (AP) Psi i

] 6) C2-310 Limitorque RCS 2750/2750 Open Yes Closed 2750 (1) ,

! 3-GM58FN SMB-OO-15 Charging i velan Gate 1800 ppm Isolation 3", 1500 psi 73 C2-373 Limitorque Charging 2750/2750 Open No (Operation Closed 2750 (1) 3-CM58FN SMB-DO-15 Pump Mini- trom nenchboard)

Velan Gate 1800 RPM Flow Isolation 3*, 1500 psi O SI-836 Limitorque High Head 2750/2750 Closed (may be No (Operation; Open 2550 (1) 3-GM58FN SMB-OO-15 SI to RCS open under from Benchboard)

Velan Gate 1800 apM Cold Leg administrative 3", 1500 psi Isolation control)

9) SI-067A, n Limitorque Boron 2750/2750 closed Yes Open 2550 (1) i 3-GM-50FN $5-00-15 Inj. Tant Westinghouse 3600 RPM Inlet Gate Isolation j 3", 1500 psi
10) SI-867C, D Limitorque Boron 2750/2750 Closed (may be Yes Open 2550 (1) 3-GM-58rw SMB-00-15 Inj. Tank open under 2 Velan Gate ISOC ppn Outlet administrative l 3*, 1500 pti Isolation control) i 11) SI-669A, B Limitorque Righ IA. 2750/2750 Closed (may be No g* Operation Open 2550 (1) i 3-GM58FM SMB-00-15 SI to RCS open under from Benctiooard)

.j velan Gate 1800 RPM Wot Iags administrative i 3*, 1500 psi control) i i 12) Fw-151A, B, C Limitorque SC Aux 1445/1445 Open Yes (Receive auto Open 1167 (21 j D, E, F Globe SMB-OO-10 FD Control open signal even

} 3*, 600 psi 1800 RPM from A, "B" though normally 3 or *C" NDR open) i e?

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NOTES -

TABLE 1 (1) Charging pumps discharge or suction pressures were obtained from ,

the Technical Manual which is considered a conservative determination for valve open/close differential pressure since it  ;

does not take'into account line losses.

(2) Aux. feedwater pump discharge pressure as calculated from TDM value assuming worst condition (one aux. feedwater line break and low NPSH).

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nntz 2 Petor operated valve nnist verificatico Measured Te riant valve purs>- valve Pvufacturer otro calculated Movats sw Location t . D./ Tyre facturer Brust Torgme rs B rust Tor 7m rs Brust (ths. ) As (1)

Ibs. rt.-tbs. tbs. rt-th - Cpen Close Op S1-836 3 *-atS8 m Velan 6,170 111.0 8,852 159.0 0.2 10,834 9,260 2.1 (rw Gate)

(2) tbs. rt.-tbs. tbs. rt-th. - 4e Close op 5!-467 A 3-CM88 nal wend 9,250 - 9,468. 133. 0.2 10,000 10,260 1.'

S1-467 8 3-028nal We=3 9,250 - 9,468. 133. 0.2 9,357 10,100 1.

(rv Gate) ,

(3)

Ibs. rt.-tbs. Ibs. ft.-tbs. C. pen Close op St-867C 3-OtS8m velan 4,750, 66.0 8,852.0 159.0 0.2 9,696. 9.646. 1.'

51-8670 3-OtS8tN velan 4,780. 86.0 8,852. 159.0 0.2 9,670. 9,098. 2.1 (4) tbs. ft.-tbs. tbs. rt .-tlui . 4en Close Op 51-869A 3-GtS8FN Velan 4.780. 80.0 8,852 159. 0.2 10,263. 9,049. 1.!

$1-469a 1-OtS8tw velan 4.780 80.0 8,852. 159. 0.2 9,680. 9,960. 1.

fW = Flex wedge Fs = system need Factor

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% Limitorcpae stroke Time h ats Data W

J hoq'd Tt>rQue Switch As 14 f t (Seconds ) Base (1P) S rust (Ib8.) Comments

% Cloes WC nan Max Open Close open Close 8.75 1.25 3.25 -

9.5 10,000 9,000 As lef t thrust eacoeds hats aM calculated levels >

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I close WC lam Max cron Close open i'

2.0 3.0 close valves are normally closed, safety 1.75 2.00 5.1 5.3 8,500 13,800 position .s open. stall thrvet I' 8.0 2.00 5.5 -

8,500 13,800 [l l available to esen during initial 20%

! gen stroke. As left thrust exceeds i M0YAts.

bclose M Nm Max open Close ogen Close Q 1.50 1.12 3.00 9.0 -

10,000 9,000 Stall thrust available to open i 1.V5 1.12 3.00 9.9 -

10,000 9,000 A ring initial 20% open stroke. Valves l are noras11y closed; safety position 1s open, i

l E close M *a Max open Close open Close O. 1.50 1.0 2.75 9.1 - 10,000 9,000 Valves are normally closed, safety ,

O 1.50 1.0 2.75 9.1 -

10,000 9,000 position is open. stall thrust avail-able Aring 20% open stroke.

fW = Flex Wedge rs = Systea BreM ractor T1  :

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F 7 Measured Plant Valve lunu- Valve Manufacturer Dtro calculated

  • wats location I .D./ Tyre facturer Thrust Torque y  % rust Torque rs  % rust (Ibs.)

(5) 01-1158 8-042m N C-nirling Ibs. ft.-tbs, tbs. rt.-tbs. Open Close 01-1150 8-cM42m N C-Darling 4,800 91.0 4,515 85.3 0.2 4,780 4,860 (fv Cate) 4,800 91.0 4,515 85.3 0.2 4,700 4,640 (6)

Ibs. f t . -Ibs . tbs. ft.-tbs. Open Close ci-275A 2-mS8m Velan 11,000 129.0 11,845. 150.0 0.2 12,000 12,080 01-2750 2-mS8m Velan 11,000 129.0 11.845 150.0 0.2 11,720 11,380 of-275C 2-mS8m Velan 11,000 139.0 11,845 150.0 0.2 13,020 12,380 (Globe)

(7) tbs. ft.-tbs. Ibs. f t . -!bs . Open Close 01-115C 4-e42m N C Darling 1,852 31.0 1,756 30.0 1,780 1,78C-oi-115E 4-e 42 m N C Darling 1,852 31.0 1,756 30.0 2,000 2,400 (IV Gate)

(8)

Ibs. ft.-ths, tbs. ft.-tbs. Open Close 01-289 3GMSarN Velan 4.780 80.0 7,262 130.0 0.2 7,900 7,810 (iv Cate)

(9)

Ibs. f t . -Ibs . Ibs. ft.-tbs. Open Close 01-110 3GM5SfH Velan 9,438 147.0 7.262. 130. 0.2 6,900 6,820 (IV Cate)

IV = Flex Wedge rs - Systes n eead Factor i

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.. i DM Lialtorque Stroke Tim Mvats Data heq'd Torque Switch As Lef t (Sectwis) Base (AP) Wrust (ths. ) Ccswnts

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OW tim mx Open Close gen Close Stall thrust available to cien 1*, g, 1*

i.u 1.75 10.1 10.1 8.9 9,500 6,000 9,500 6,000 de u s iniual 20s qen s - e valves normally closed; safety 1.12 1.75 8.9 position gen.

cW tim ex gen Close gen Close Noasured thrust exceeds cale. ud 1.69 2.75 7.0 7.0 8,000 9,900 MovATs. valves norelly gen; safety

{'$ g'5 1.62 2.75 6.8 7.3 8,000 9,900 position closed.

g*75 l*75 1.62 2.75 8.1 7.8 8,000 9,900 (W taxa mx gen Close qen Clow Measured seat thrust exceeds calc.

qen close 1.25 2.00 3.9 4.0 3,200 2,700 Measured seat thrust exceeds calcu-1.0 1.0 1.25 2.00 5.5 5.7 3,200 2,700 lated thrust; valves 1.5 1 . ", norm 11y gen; safety position closed.

CW tin mx gen Close gen Close Measured seat thrust exceeds cale-4 *" U*** 1.00 2.75 9.3 9.1 10,000 9,000 ulated thrust; 3.0 3.0 valves normily gen; safety position closed.

4*^ CIj* CW tka ex cren Close qen Close T.S. sax. verified as 3.0 by Limitorque 2' 2.0 3.0 6.0 6.1 10,000 9,ooo Increase it to ver&r's calculated thrust. valve norelly open, safety position closed. valve moved to safety position during previous FW = Flex Wedy Fs = System %re d Factor SI actuation signals.

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Measured Torque Plant Valve Manu- Valve Manufacturer DLCo calculated Movats Switch location I.D / Type facturer  % rust Wrque y %tust Wrque y  % rust (ths.) As taft (10)

Ibs. r c .-ths. Ibs. ft.-ths. Open Close Open (

Q1-373 3cM58m velan 4,780 80.0 7,262. 130. 7,890 7,950 1.0 l (11)

Ibs. rt.-ths. Ibs. rt-th - Open Close open a 01-150 2-m 42rs Aloyco 1,140. 9.0 1,240. 10.0 0.2 1,710 1,700 1.0 l l (12)

Ibs, rt.-tbs. tbd. ft.-ths . Open Close Open a m-151A 9,587 147.0 10,886 167.0 0.2 14,400 14,400 1.0 m-151B Ccpes-W1can 9,587 147.0 10,886 167.0 0.2 13,960 14,000 2.0 m-151C 3 *-VtN-60 Inc. 9,587 147.0 10,886 167.0 0.2 14,620 13,900 2.0  ;

m-151D 9.587 147.0 10,886 167.0 0.2 14,500 14,800 1.75 -

m-151E 9,587 147.0 10,886 167.0 0.2 13,680 14,420 1.75 m-151r 9,547 147.0 10,886 167.0 0.2 14,020 14,300 1.25 4

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Roo'd torque Switch As 14f t (Seconds) Base (AP) 1t.fust (ths.) Cments

oe,CA
Na Max open close Coen Close measured thrust exceeds calculated 1.0 1.00 2.75 9.97 10.1 10,000 9,000 thrust. Valve normal-ly open, safety position closed.

joe. CA: les Max open close open close Measured thrust exceeds calculated  ;

(o 2.0 4.0 10.0 10.1 2,300 1,800 thrust. valve {

normally closed, safety position open. g

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.0 CA: Nas Max 0 Fen Close Open Close these valves are normally open and fi

.0 2.0 3.0 20.7 21.0 9,200 9,500.0 safety position is open. Stroke time t;~

75 , 2.0 3.0 19.7 19.9 9,200 9,500.0 and thrust measurements confira valve

. /c., j 2.0 3.0 22.2 22.5 9,200 9,500.0 furwtions. As left thrust exceeds

.75 j 2.0 3.0 20.8 21.1 9,200 9,500.0 awats and calculated thrust levels. *

.75 2.0 3.0 20.7 19.5 9,200 9,500.0 'i 2.0 3.0 20.7 20.8 9,200 9,500.0-k Tl I APEllTUllE l CAllD

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Attachment Page 1 of 1 DEDUSTRY STANDARD CA14ULATIONS The thrust required 'to open or close a gate or globe valve is the thrust necessary to overcome the following three forces:

Stem thrust or frictional force (Tf)

Packing Load (Lp)

Stem unbalance load (Ls)

The stem thrust is caused by the differential pressure (DP) across the valve or disc which forces the disc against the seat. This load is normal to the  ;

direction of the valve stem thrust. The friction between the disc and the seat caused by this pressure load is overcome by the stem thrust. l l

Stem thrust (Tf) = DP x AS x fy  !

Where: As = seat area fv = valve factor (dependent upon valve type)

DP = maximum design differential pressure i The packing load (Lp) is the dras created by the valve stuffing box on the stem. These values are based on experience and stuffing box design and are -

obtained from Limitorque or th,e valve manufacturer. 1 l

The stem unbalance load (Ls) is the load required when the system operating pressure (Po) working against the stem area (Ao) forces the stem toward the opening direction since it is not balanced axternally.

Stem Unbalance Load (Ls) = Po x Ao The total required thrust (T) is the sum of tie three forces described above.

T = Tf + Lp + Ls

_- . - - - - . - -