ML20010A127

Final Deficiency Rept Re Westinghouse three-inch Gate Valve Failure to Close,Initially Reported on 801031.Vendor Recommendations to Guarantee Full Closure Provided

ML20010A127
Person / Time
Site:	Marble Hill
Issue date:	07/31/1981
From:	Shields S PSI ENERGY, INC. A/K/A PUBLIC SERVICE CO. OF INDIANA
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 10CFR50.55E, S80-32, NUDOCS 8108110094
Download: ML20010A127 (4)

Text

-

~

0731814001 .

1

$ 6 so.Syg PUBLIC ,%/]'

SERVICE INDIANA 3,1y 31, 1931 S80-32 -

h S. W. Shields .E; ,/ll]C 101937 u ,

Senior Vice President - 8 g ,

Nuclear Division g fG U

%i f\

V Mr. James G. Keppler, Director Docket Nos.: STN 50-546 U.S. Nuclear Regulatory Commission STN 50-547 Region III Construction Permit Nos.:

799 Roosevelt Road CPPR-170 Glen Ellyn, IL 60137 CPPR-17)

Marble Hill Nuclear Generating Station - Units 1 and 2

Dear Mr. Keppler:

On October 31, 1980, Mr. T. D. Geib of Public Service Company of Indiana,_Inc.

(PSI) notified your office of a potentially reportable incident as required by 10 CFR 50.55(e). During preoperational testing at a domestic station and at a foreign station, problems were encountered when testing Westinghouse Electro-Mechanical Division manufactured three inch gate valves, Model 3GM88, 1500 lb. class. Westinghouse furnishes this valve to its customers in Code Class 1, 2, and 3 applications. In the Code Class 2 and 3 applications the valve identification only is changed to 3GM78 or 3GM58, respectively. The tested valves failed to completely close under preoperational test conditions (i.e., approximately 2700 psi as flow approaches zero) which are less severe than the equipment specification design conditions (i.e., 2750 psi as flow approaches zero). The valves stroked to significantly restrict flow, but the full stroke was not accomplished to trip the " closed" position indication contacts in the motor operator or to seat,the valve disc within the valve body.

/

As discussed in PSI's interim-report of December 1,1980, two of the subject valves are used in each unit for " active" functions (i.e., mechanical operation is required to accomplish a safety function). For these valves, Westinghouse has recommended that valve operator gear ratios be modified or limit closing control be utilized depending on the model of valve operator.

. However, during laboratory testing Westinghouse determined that their four inch gate valves also experienced the subject closure prob'.ec As a result, Westinghouse extended their evaluation to include all of their remaining Electro-Mechanical Division manufactured valves. The results of their analysis predicted that closure problems could also be anticipated with these valves in the 6, 8, 10, 12, 14, 16 and 18 inch sizes.

w ~il

_ .5 8108110094 810731' /

PDR ADOCK 05000546 j /[

S PDR rAU6 3 1981 P. O. Box 190, New Washington, Indiana 47162 812. 289.1000

)

0731814001

~ '

_2_

~

James G. Keppler, Director July 31, 1981 PUBUC S80-32 SERVICE INDIANA Westinghouse has conducted a more detailed review of the safety related functions these valves are required to perform. The final functional requirements for motor operated valves are based on the single failure criteria and the Westinghouse reference Emergency Operating Instructions.

Based on the low probability of passive failures during the short term injection phase, the functional requirements for MOV's do not. address the isolation of passive failures during the injection phase. The Emergency Operating Instructions, in certain applications, require stopping the high pressure safety injection pumps during the switchover to hot leg recirculation. The pumps are not restarted until all of the hot leg recirculation valve realignments have been accomplished. For this condition, valve closure differential pressure will be zero. On that basis, these functional requirements eliminate seven of the model 4GM87 and 4GM88 valves previously identified in PSI's March 31, 1981, interim report as requiring modifications. The remaining two valves originally identified as model 4GM87 were also discovered to be model 4GM77. A list of the valves which will require modification is provided in Attachment I to this letter.

Depending on which valves failed to close the possible consequences of incomplete valve closure are:

Potential incomplete isolation of pressurizer PORV.

Potential cavitation of a centrifual charging pump or safety injection pump due to operation beyond maximum runout flow.

Potential inal'.2 ity to isolate RCS pressure boundary.

Potential degtadation of safety injection flow below values given in SAR.

Depending upon the system closing differential pressure requirements and the valve model in question, the changes Westinghouse recommends to guarantee full closure vary. These involve one or any combination of the following:

I Torque switch adjustment Increasing the operator gear ratio to guarantee adequate thrust j capacity at 80 percent voltage Rewiring the operator for limit closing control Changing the operator for limit closing _ control Changing to a larger foot pound rated motor Changing to a larger size limitorque operator.

Westinghouse recommended changes to affected valves are identified in l

Attachment 1.

t I

0731814001 -

James G. Keppler, Director July 31, 1981 PUBUC S?0-32 4 SERVK;E INDIANA This letter is intended to fulfill the requirements of a final report as defined in 10 CFR 50.55(e). If you have any questions on this report, please feel free to contact me.

Sincerely, S. W. Shields TDG/kdt cc: Director of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 E. R. Schweibinz, P.E.

J. J. Harrison g i

l i

_- . _ , _ - _ _ _ - - --. . . , _ . _ . . . _ . _ , . _ _ . . - ~.- . _ . _ . . . _ . _ _ . _ __. _ _ _ . _ _

073181400.1.. .

ATTACHMENT 1 -

" ACTIVE" VALVE APPLICATIONS

_ FUNCTION LOCATION NO. VALVE I.D.( MODIFICATION CVCS LCV-112B,C 4GM72FB Torque Switch Adjustment LCV-112D,E 8GM72FB Torque Switch Adjustment or Gear Change (2) 8105 3GM88 Gear Change or Rewire Operator 8106 3GM88 Gear Change or Rewire Operator l

S1S 8804A,B 8GM74FE Torque Switch Adjustment l 8806 8CM72FB Torque Swftch Adjustment or Gear Change (2) 8807A,B 6GM72FB Torque Switch Adjustment l 8821A,B 4GM77FH Installation of Larger Operator 8923A,B 6CM72FB Torque Switch Adjustment or Gear Change (2) 8924 6CM72FB Torque Switch Adjustment RHRS 8701A,B. 12GM88SE Torque Switch Adjustment 8702A,B 14GM88SE: Torque Switch' Adjustment i

l 8716A,B 8CM74FE Torque Switch Adjustment l NOTES (1) This number is found on the yoke mounted nameplate. This number occupies the first three l positions of a six position number.

l (2) To be established after completion of final analysis. ,

I I