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#REDIRECT [[A07138, Forwards Addl Info to Support Util 860611 & 1028 Responses to IE Bulletin 85-003 Re motor-operated Valve Common Mode Failures,Per NRC 880324 Request]]
| number = ML20154M175
| issue date = 05/23/1988
| title = Forwards Addl Info to Support Util 860611 & 1028 Responses to IE Bulletin 85-003 Re motor-operated Valve Common Mode Failures,Per NRC 880324 Request
| author name = Mroczka E
| author affiliation = NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
| addressee name =
| addressee affiliation = NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
| docket = 05000423
| license number =
| contact person =
| document report number = A07138, A7138, IEB-85-003, IEB-85-3, NUDOCS 8806010200
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE, UTILITY TO NRC
| page count = 6
}}
 
=Text=
{{#Wiki_filter:.
N6RTHEAST UTILITIES                                    cenerai Ottices . seia-n sireet, seriin. Connecticui
                          -        c ARTFORD. CONNECTICUT 06141-o270 L  L T;  Cr,' "'XlC',~. ''
                              ,            ,                                    (203) ses sooo May 23, 1988 Docket No. 50-423 A07138 Re:    IE8 85-03 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 3 Additional Information IE Bulletin 85-03 MOV Common Mode Failures In a    letter dat      June 11, 1986,II) as supplemented by a letter dated October  28, 1986, g Northeast Nuclear Energ{3g mpany (NNEC0) subm NRC Staff a response to IE Bulletin 85-03,            providing certain information and detajiing NNEC0's program for addressing the NRC Staff concerns outlined in the Bulletin for Millstone Unit No. 3.
In a letter dated March 24, 1988,54) the NRC Staff requested that NNEC0 provide auditional information to support the Staff review of NNEC0's June 11, 1986 submittal . Accordingly, NNEC0 hereby provides the attached additional information.
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I (1)  J. F. Opeka letter to Dr. Thomas E. Murley,            "IE Bulletin 85-03, MOV Common Mode Failures," dated June 11, 1986.
(2)  J. F. Opeka letter to Dr. Thomas E. Murley,            "IE Bulletin 85-03,                  M0V Common Mode Failures," dated October 28, 1986.
(3)  IE Bulletin 85-03, "Motor-0perated Valve Common Mode Failures During Piant Transients Due to Improper Switch Settings," dated November 15, 1985.
(4)  L. H. Bettenhausen letter to E. J. Mroczka, "Additional Information on IE8 85-03," dated March 24, 1988.
i 8806010200 880523 i          PDR Q
ADOCK 05000423 DCD                                                                    ffi
 
U.S. Nuclear Regulatory Commission A07138/Page 2 May'23, 1988 If you have any questions, please contact us.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY
                                                              ~
M                    <
Erf. Firoczkaff Senior Vice President l
Attachment cc: W. T. Russell, Region I Administrator R. L. Ferguson, NRC Project Manager, Millstone Unit No. 3                  _i W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos.1, 2, and 3 Division of Operational Events Assessment, NRR L. H. Bettenhausen, Chief, Projects Branch No. 3, Region I l
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:.                                                                                                                                                                              1 4
1 Docket No. 50-421                          l A07138                      -l
                                                                                                                                                                                .i
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1 Attachment                                                                                                  )
Millstone Nuclear Power Station, Unit No. 3 l
Additional Information IE Bulletin 85-03 M0V Common ~ Mode Failures                                                                                            i
                ,'                                                                                                                                                                i i
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1 May 1988 1
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r Attachment A07138/Page 1 May 23, 1988 Millstone Unit No. 3 Additional Information IEB 85-03 "MOV Common Mode Failures" Question 1:
Has water hammer due to valve closure been considered in the determination of pressure differentials? If not, please explain.
Resoonse:
Water hammer due to valve closure was not considered in the determination of pressur e differentials. Valve opening and closing tices for the MOVs evaluated range from 5-30 seconds. Water hammer is not of concern unless valve stroke times are much less than one second.
Question 2:
Unlisted MOVs 17A,178, and 170 are shown normally open in zones F-2, H-2, and C-2, respectively, of Figure 10.3-1, Sheet 1 of 5, Amendment 18, March 1986.
They are located in the steam lines from the steam generators to the AFW TurMne, in series with normally closed pneumatic valves. As required by Action Item a of the bulletin, assume inadvertent equipment operations. How          ,
would steam flow to the AFW turbine be ensured if these MOVs were to be left        !
closed inadvertently? Revise Attachment 4 of the response of 10/28/86 to            l include these MOVs, or justify their exclusion.
Resoonse:                                                                      ;
1 It is NNECO's position that IE Bulletin 85-03 does not apply to MOVs 17A,      i 178, and 170. IE Bulletin 85-03 identifie; concerns regarding gate-type MOVs. MOVs 17A, B, and D are stop check valves (Walworth Drawing            .
No. A-12279-M-3C) and are considered self-actuating in the Millstone Unit      l No. 3 In-Service Test Program. Motor operator thrust requirements for these valves are significantly less severe than for typical gate-type MOVs. Specifically, reverse flow in MOVs 17A, B, and D results in valve closure without any thrust required from the operator. Any differential pressure in the forward direction        (i.e.,  valves inadvertently left closed)  directly    assists in valve opening.        In fact,      increased differential pressure in the forward direction provides              increased assistance in opening these valves.
In summary, NNEC0 has excluded MOVs 17A, B, and D from our response to IEB 85-03 since characteristics of these stop check valves means that they are not subject to the type of failures identified in the bulletin.
 
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l Attachment                                                                            .
A07138/Page 2                                                                          !
May 23, 1988
                                                                                              )
I Question 3:                                                                          I The proposed program for Action Items b, c, and d of the bulletin is incom-plete. Please provide the following details,
: s. Commitment to a training program for setting switches and maintaining            I valve operators,
: b. Commitment to justify continued operation if a valve is determined to be inoperable,
: c. Description of a method for extrapolating valve stem thrust determined by testing 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.
ReJip_9J1H:
e 3a. NNEC0 currently has a training program for personnel who perform the maintenance of valve operators.
Personnel performing M0 VATS data acquisition and valve analysis have completed training programs given by M0 VATS. These programs cover switch setting and interpretation of test results.
3b. NNEC0 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.
3c. The conventional formula, as follows, will be used to extrapolate valve stem thrusts when measured at less than maximum differential pressures:
ValveThrust(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 a similar form by Limitorque, M0 VATS, and the valve manufacturers.
The constants and the stuffing box load can only be determined
 
Attachment A07138/Page 3 May 23, 1988 experimentally.      These values can be determined from the static tests and tests at lower differential pressures. The formula can then be used to determine the stem thrusts required at the higher differential . pressures.
3d. Signature testing (M0 VATS or similar) is an acceptable alternative to full DP testing at the plant, especially for MOVs where DP testing is impractical. In the absence of full DP testing, original design thrust and running load requirements (verified by analysis or -
partial flow DP signature testing) can be ensured through static 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.
3e. NNEC0 presently considers applicable industry recommendations in the preparation of procedures to ensure maintenance of correct switch settings.
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