A07122, Forwards Addl Info in Response to IE Bullentin 85-003 Re motor-operated Valve Common Mode Failures.Water Hammer Due to Valve Closure Not Considered in Determination of Pressure Differentials

Forwards Addl Info in Response to IE Bullentin 85-003 Re motor-operated Valve Common Mode Failures.Water Hammer Due to Valve Closure Not Considered in Determination of Pressure Differentials

ML20151P035
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	04/18/1988
From:	Mroczka E, Sears C CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
A07122, A7122, IEB-85-003, IEB-85-3, NUDOCS 8804260070
Download: ML20151P035 (8)

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NORTHEAST UTILITIES o.nor.i Orvic.. . seio.n sir..i. seriin. Connecticut I rIIdU$sSNc"*$

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P.O. BOX 270 H ARTFORD, CONNECTICUT 061410270 k k J 7.,7dMCMC2, (203) 665-5000 April 18, 1988 Docket No. 50-213 A07122 Re: IEB 85-03 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 i Gentlemen:

Haddam Neck Plant Additional Information IE Bulletin 85-03 MOV Common Mode Failures in a [[letter::B12091, Responds to IE Bulletin 85-003, Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings, Per 851115 Request.Related Concerns Identified in IE Info Notice 86-029 Also Addressed|letter dated June 11,1986]],(I) Connecticut Yankee Atomic Power Compg (CYAPC0) submitted to the NRC Staff a response to IE Bulletin 85-03, providing certain information and detailing CYAPCO's program for addressing the NRC Staff concerns outlined in the Bulletin for the Haddam Neck Plant.

In a letter dated March 18, 1988,(3) the NRC Staff requested that CYAPC0 provide additional information to support the Staff review of CYAPCO's June 11, 1986 submittal . Accordingly, CYAPC0 hereby providsa the attached additional information.

(1) J. F. Opeka letter to Dr. Thomas E. Murley, "IE Bulletin 85-03, M0V Common Mode Failures," dated June 11, 1986.

(2) IE Bulletin 85-03, "Motor-0perated Valve Common Mode Failures During ,

Plant Transients Due to Improper Switch Settings," dated November 15, )

1985.

(3) L. H. Bettenhausen letter to E. J. Mroczka, "Additional Information on IEB 85-03," dated March 13, 1988. j i

fd 8804260070 880418 PDR ADOCK C5000213 ){

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U.S. N'; clear Regulatory Commission A07122/Page 2 April 18, 1988 If you have any questions, please contact us.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY 5.b . b  %.

E. J. Hroczka 9 Senior Vice President L  :

By: C. F. Sears Vice President Attachment cc: W. T. Russell, Region I Administrator A. B. Wang, NRC Project Manager, Haddam Neck Plant J. T. Shedlosky, Senior Resident Inspector, Haddam Neck Plant Division of Operational Events Assessment, NRR L. H. Bettenhausen, Chief, Projects Branch No. 3, Region I i

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Docket No. 50-213 A07122 Attachment Haddam Neck Plant .

Additional Information IE Bulletin 85-03 MOV Common Mode Failures t

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April 1988

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e Attachment A07122/Page 1 April 18, 1988 Haddam Neck Plant Additional Information IEB 85-03 "MOV Common Mode Failures" Question I:

Has water hammer due to valve closure been considered in the determination of pressure differentials? If not, please explain.

CYAPC0 Response:

Water hammer due to valve closure was not considered in the determination of pressure differentials. Valve opening and closing times for the M0Vs evaluated ranged from 5-30 seconds. Water hammer is not of concern unless valve stroke times are much less than one second.

Question 2:

Unlisted MOV SI-M0V-24 is shown locked open in Zone G-3 of Drawing 16103-26010, Revision 25, in the suction line from the RWST to the centrifugal charging pumps and the HPSI pumps. Is power removed from the motor in addition to locking this M0V open? If not, what is the effect of inadvertent equipment operations as specified in Action Item a of the bulletin? Please revise Attachment 1 of the June 11, 1986 respons. to include this valve.

CYAPC0 Resoonse:

M0V SI-MOV-24 is maintained in the locked open position with the poyyy removed. For this reason, Bulletin 85-03 does not apply to SI-M0V-24 Question 3a:

Revise Attachment 1 of the June 11, 1986 respoase to include the following MOVs, or justify their exclusion. As specified in Action Item a of the bulletin, assume inadvertent equipment operations.

a. Valve FW-MOV-344 (2-inch) is shown normally closed in Zone G-4 of ,

Drawing 16013-26018, Sheet 4, Revision 3. It is in parallel with j (1) Position of valves depicted on drawings are for informational purposes only. Actual valve lineups are specified by operational procedures for the appropriate plant configuration.

Attachment A07122/Page 2 April 18, 1988 normally closed air-operated Valve FW-FCV-295 (3-inch). These valves control flow from the charging pumps to the 2-inch header for lines leading to cold leg loops 1 through 4. How would opening of this MOV from the normally closed position be ensured?

CYAPC0 Response:

It is CYAPC0's position that IE Bulletin 85-03 does not apply to FH-MOV-344 (incorrectly designated FW in the NRC question).

The Bulletin only applies to MOVs required for high-pressure safety injection (and auxiliary feedwater). The safety injection flow path for the Chemical and Volume Control System is via CH-M0V-292 B and C which have been addressed in CYAPC0's original submittal.

The primary function of FH-M0V-344 is for filling the reactor coolant system for start-up. The valve is also used as an alternate lineup for the recirculation mode of Emergency Core Cooling (in the event of failure of normal flow path via HPSI). This mode of operation using FH-MOV-344 is only temporary until planned modificatio complete. In a letter dated Ap:il 10,1986,g toCYAPC0 the HPSI system provided are details of this alternate flow path and planned HPSI system modifications.

In summary, Valve fH-M0V-344 is used for 1) filling the RCS for start-up and 2) as an alternate flow path for the recirculation mode of emergency core cooling. Since the valve is not credited for any safety injection or auxiliary feedwater events, Valve .H-M0V-344 has been excluded from the scooe of IE Bulletin 85-03.

Questioi. 3b:

Valve FH-MOV-578, -535, -522, and -508 (1)-inch) are normally open on Drawing 16103-26007, Sheet 1, Revision 7. They are located in lines leading from the header atentioned in Item 3.a above to cold leg loops 1 through 4.

How would discharge to the cold legs be ensured if these MOVs were inadver-tently left closed?

CYAPC0 Resoonse:

Valves FH-M0V-578, -535, -522, and -508 are normally closed. This is correctly indicated on the latest revision of the applicable drawing (2) J. F. Opeka letter to C. I. Grimes, "Probabilistic Safety Study LOCA Analysis," dated April 10, 1986.

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Attachment i A07122/Page 3 l April 18, 1988 l

l (16103-26018, Sheet 6 of 8, Revision 1). Further, these valves have been excluded from the scope of IE Bulletin 85-03 on the same basis as for FH-M0V-344 described above, since these valves are just downstream of FH-M0V-344.

Question 4:

Valve FW-MOV-35 is called normally closed in the response, but it is shown normally open on Drawing 16103-26013, Sheet 1, Revision 40. Please correct this discrepancy. Also, further explain the fix described for FW-MOV-35 in Attachment 1 of the response. This MOV is in a line leading from the turbine-driven AFW pumps to all four steam generators. Verify that the time delay caused by either shutting down the AFW pumps or shutting the manual valves before operating this valve does not exceed the time limits assured in the design analysis.

[_LAPC0 Resoonse:

Valve FW-M0V-35 is normally closed.

To address the inadequate design differential of FW-MOV-35 (550 psi design versus 1300 psi required), CYAPCO has revised the applicable procedures to include the following guidance:

"If FW-M0V-35 fails to open, it will be necessary to stop AFW (Auxiliary Feedwater) pumpt or close discharge valve, open FW-M0V-35, and restart pumps."

Use of the alternate AFW flow path via FW M0V-35 is not credited in any FSAR analyses. This alternate flow path was established in 1981 with the installation of the AFW pump discharge cross-tie valve (FW-M0V-160).

Installation of the cross-tie valve (FW-M0V-160) and the establishing of '

the alternate flow path were performed to enhance the reliability of the AFW system.

Since the alternate AFW flow path via FW-MOV-35 is not credited in any FSAR analyses, it is concluded that the time delay associated with the added procedural steps will not exceed the time limits assumed in design basis analyses.

Question 5: l The proposed program for Action Items b, c, and d of the bulletin is incom-plete. Please provide the following details. ,

a. Commitment to a training program for setting switches and maintaining valve operators.

Attachment A07122/Page 4 April 18, 1988

b. Commitment to justify continued operation if a valve is determined to be inoperable.

c. Descriction of a method for extrapolating valve stem thrust deternined by testin] at less than maximum differential pressure.

d. Justification of a possible alternative to testing at maximum differen-tial pressure at the plant.

e. Consideration of applicable industry recommendations in the preparation of procedures to ensure maintenance of correct switch settings.

CYAPC0 Response:

Sa. CYAPC0 currently has a training program for personnel who perform the maintenance of valve operators.

Personnel performing M0 VATS data acquisition and valve analysis have cc:npleted training programs given by M0 VATS. These programs cover switch setting and interpretation of test results.

Sb. CYAPC0 presently has procedures in place to deal with equipment declared inoperable. Justification for continued operation will be based upon an evaluation of the valve's effect on Technical Specifi-cations or Design Basis requirements for system function.

Sc. The conventional formula, as follows, will be used to extrapolate valve stem thrusts when measured at less than maximum differential pressures:

Valve Thrust (open) - K x DP [(Seat Area x Seat Coefficient) -

Stem Area] + Stuffing Box Load Valve Thrust (closed) - K x DP [(Seat Area x Seat Coefficient) +

Stem Area] + Stuffing Box Load This formula is based on obvious physical principles and is used in l a similar form by Limitorque, M0 VATS, and the valve manufacturers.  !

The constants and the stuffing box load can only be determined experimentally. These values can be determined from the static tests and tests at lower differential pressures. The formula can ,

then be used to detennine the stem thrusts required at the higher differential pressures.

5d. Signature testing (M0 VATS or similar) is an acceptable alternative to full DP testing at the plant, especially for MOV:. where DP l testing is impractical. In the absence of full DP testing, original )

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. I Attachment A07122/Page 5 April 18, 1988 design thrust and running load requirements (verified by analysis-or partial flow DP signature testing) can be ensured through static i

signature testing.

Many critical operational parameters can be measured through static signature testing, such as control switch trip thrust, running load, and bypass switch actuation. Adequate control of these parameters through signature testing can maintain proper MOV operation without the need for full DP testing.

5e. CYAPC0 presently considers applicable industry recommendations in  ;

the preparation of procedures to ensure maintenance of correct i switch settings.

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