ML20155J308

Responds to IE Bulletin 85-003, Motor-Operated Valve Common Failures During Plant Transients Due to Improper Switch Setting. Westinghouse Owners Group Developed Methodology for Determining Which motor-operated Valves Included

ML20155J308
Person / Time
Site:	Kewaunee
Issue date:	05/14/1986
From:	Hintz D WISCONSIN PUBLIC SERVICE CORP.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
CON-NRC-86-63 IEB-85-003, IEB-85-3, NUDOCS 8605230102
Download: ML20155J308 (12)

Text

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s NRC-86-63 oma 1,3 WPSC (414) 433-1234 ) TELEX 5101012698 WPSC GR8

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i TELECOPER (414)433-1297 Nj EASYUNK 62891993 WWCONWN PUBUC SEmnCE CORPORATION 600 North Adams

• RO. Box 19002

• Green Bay, WI 54307-9002 l

May 14, 1986 Mr. J. G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Mr. Keppler:

Docket 50-305

! Operating License DPR-43 Kewaunee Nuclear Power Plant I.E. Bulletin 85 Motor Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Setting The subject bulletin requested that we review and document the design basis for selected motor operated valves in the High Pressure Coolant Injection System and the Emergency Feedwater System. The methodology used by Wisconsin Public Service Corporation for determining which valves to include was developed by the Westinghouse Owners Group. Attachment I contains Tables I & II which reports the results of this review. Attachment II details the requested schedule for completion of items b through d.

l Very truly yours, D. C. Hintz Manager - Nuclear Power Subscribed and Sworn to BeforeMJ This /4/VA Day DJN/jms of ///de# 1986 Attach. 0 )A, & hw tb cc - Mr. Robert Nelson, US NRC Mr. G. E. Lear, US NRC My Commission Expires:

Director, Office of I&E, US NRC June 28, 1987 8605230102 860514 PDR

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N1-128.1A Attachment I Letter from D. C. Hintz to J. G. Keppler Dated May 14, 1986 Kewaunee Nuclear Power Plant Wisconsin A "c Service Corporation 4

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Safety Injection SI-2A 200 200 30 29 Open -1 Pump Suction from Boric Acid Tanks Close - 2 Safety Injection SI-2B 200 200 30 29 Open -1 Pump Suction from Close - 2 Boric Acid Tanks Safety Injection SI-4A 200 200 200 30 Open -3 Pump Suction from Close - 4 RWST Safety Injection SI-4B 200 200 200 30 Open -3 Pump Suction from Close - 4 RWST Safety Injection SI-SA 200 200 200 30 Open -5 Pump Suction Close - 5 Isolation Valves Safety Injection SI-58 200 200 200 30 Open -5 Pump Suction Close - 5 Isolation Valves Safety Injection SI-15A 2750 2750 2330 2380 Open -6 to Reactor Vessel Close - 6 Isolation Valve Safety Injection SI-15B 2750 2750 2380 2380 Open -6 to Reactor Vessel Close - 6 Isolation Valve SI Pump to RWST SI-208 2750 2750 2225 2225 Open -7 Recirc. Isol. Valve Close - 7 SI Pump to RWST Recirc. Isol. Valve SI-209 2750 2750 2225 2225 Open -7 l

Close - 7

J. G. Keppler N1-128.2

. May 14, 1986 Attachment I Page 3 of 7 Justification for Table I

1. These valves must open to allow the SI pumps to take suction on the Boric Acid Tanks. The maximum delta P for this scenario is the elevation head of the Boric Acid Tanks above the valves.

2. These valves must close to allow SI pump suction to switch to the Refueling Water Storage Tank (RWST). The maximum delta P for these valves to close against would be the eleva^ tion head of the RWST above the valves = 30 psig.

3. This valve must open on a Boric Acid Tank Lo Lo Level to provide suction to the SI pumps from the RWST. The maximum delta P this valve would have to open against would be the elevation head of the RWST = 30 psig.

4. The Westinghouse Valve Specification Sheet for these valves specifies a 200 psi delta P. The Limitorque Bill of Material specifies a 100 psi delta P. In the event tne valve SI-5A/SI-5B fails i: fully close, this valve would be required to close against thi o c harge head of the RHR pump while operating in the recirculation mode. Should the valve SI-4A/SI-4B fail to close against the RHR pump discharge pressure, the control room operators would have ample time to stop the affected train of recirculation flow, thus removing the pressure, and then closing the valve.

A review of this failure mode is continuing; however, this is not con-sidered to be a safety concern.

5. This valve is normally open. The valve must close to isolate the RWST from the discharge of the RHR pumps during the recirculation mode of operation. The maximum delta P this valve would see would be the discharge of the RHR pumps = 200 psig.

J. G. Kcppler N1-128.3

,- May 14 1986 1 Attachment I i Page 4 of 7  :

, 6. This valve is normally closed. It would have to open to allow vessel j- injection. The maximum differential pressure this valve would see is i

the discharge head of the SI pumps plus the discharge head of the RHR pumps operating in the recirculation mode.

7. This valve is normally open. It must close to allow transfer to recirculation operation. The maximum delta P this valve would see is the discharge head of the SI pumps.

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• r" KNPP Design delta P Delta P Jastification for Maximum MOV Valve Number Close Open Close Open Operating of delta P Turbine Driven AFWP to AFW-10A 1100 1100 1750 17 9 Open -1 S/G 1A 1 solation Valve Cicse - 1 Turbine Driven AFWP to AFW-108 1100 1100 1750 1750 Open -1 S/B IB 1 solation Valve Close - 1 Service Water to TDAFWP SW-502 150 150 100 100 Open -2 Isolation Valve Close - 2 Service Water to 1A SW- 501 A .150 150 100 100 Open -2 Motor Driven AFWP Close - 2 Service Water to 18 SW-6018 150 150 100 100 Onen - 2 Motor Driven AFWP Close 2 1A S/G Steam Supply to MS-100A 1100 1100 100 100 Open -3 TDAFWP Isolation Valve Close - 3 IB S/G Steam Supply to MS-100B 1100 1100 1106 1106 Open -3 TDAFWP Isolation Valve Close - 3 Main Steam Admitting MS-102 1100 1100 1106 1106 Open -4 Valve to TDAFWP i Close - 4

J. G. K ppler N1-128.4

. May 14, 1986 Attachment I Page 7 of 7 Justification for Table II

1. Discharge head of the turbine driven pump at miniflow. Approved operating and emergency procedures are in place to ensure proper operation of these valves under maximum delta P conditions.

2. This valve is normally closed. It must open to allow service water to the pump suction. The maximum delta P this valve would see is the discharge head of the service water pumps.

3. This valve is normally open. It must close to isolate a faulted or ruptured Steam Generator. The maximum delta P for this valve is the lowest Steam

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Generator safety plus 3% accumulation.

4. This valve is normally closed. It must open to allow steam to the turbine driven pump. The maximum delta P for this valve is the lowest Steam Generator safety plus 3% accumulation.

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N1-128.4A 5

4 Attachment II I Letter from D. C. Hintz to J. G. Keppler

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Dated May 14, 1986 4

h Kewaunee Nuclear Power Plant Wisconsin Public Service Corporation I

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J. G. Keppler N1-128.5 May 14, 1986 Attachment II Page 1 of 2 Attachment II The following response reflects Wisconsin Public Service Corporation's proposed schedule for completion of IE Bulletin 85-03 items b through d.

Item b - WPS is currently reviewing all motor operated torque switch settings.

Any discrepancies between the actual setting and the manufacturer's recommended setting will be corrected by May 31, 1986. A procedure is being developed by the maintenance department to ensure that torque bypass and position limit switches are correctly set. This procedure will be completed prior to the start of the 1987 refueling

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outage. During the 1987 refueling outage all valves contained in Table I & II will have their switch positions verified. During the 1985 refueling outage design change request (DCR 1695) performed a review of safeguards motor control center overload devices to verify adequate sizing. Included with this review was the limitorque motor operators which are included in this bulletin. Therefore no additional work is planned in this area.

Item c - WPS will perform full flow maximum differential pressure testing on selected valves. The selection of which valves can be tested will depend on the ability of the system to be placed in a configuration where a maximum differential pressure condition can be applied. An example would be the SI pump discharge valves to the reactor vessel (SI-15A/B). During the yearly SI system flow test a maximum differ-ential pressure can be applied to these valvcs. Maximum differential pressure testing on the valves selected will be completed during the 1987 refueling outage.

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J. G. Keppler N1-128.6 i

[ May 14, 1986 l Attachment II Page 2 of 2 Justification of a test method (M0 VATS, VMODS, etc.) for valves not '

undergoing full differential pressure testing will be provided in the future. Due to the uncertain nature of this testing method, no speci-fic date for completion can be set at this time. An update to this response will be provided when a test method and time frame have been finalized.

Item d - All motor operators contained in Tables I and II are currently main-tained using preventative maintenance procedures. These procedures will be reviewed to ensure explicit acceptance criteria for torque and torque bypass switch settin.gs are included. These procedures will be reviewed and revised prior to the 1987 refueling outage. Proper operation of limit switches is verified biennially under the Inservice Testing Program.