ML20151D262

Forwards Response to Request for Addl Info Re IE Bulletin 85-003, Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings. Stated Sys Data Base Will Not Be Used as Justification

ML20151D262
Person / Time
Site:	Seabrook
Issue date:	07/18/1988
From:	George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-85-003, IEB-85-3, NUDOCS 8807250030
Download: ML20151D262 (8)

Text

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I George S. Thomas vie.he m w.w moouo.,x New Hampshire Yankee Divisi,.

NYN 88097 July 18, 1988 United States Nuclear Regulatory Comission Washington, DC 20555 Attention: Document Control Desk

References:

a) Facility Operating License NPF-56, Construction Permit CPPR-136, Docket Nos. 50-443 and 50-444 b) IE Bulletin 85-03, ' Motor-Operated Valve Common Mods Failures During Plant Transients Due to Improper Switch Settings,' dated November 15, 1985 c) PSNH Letter (SBN-1052) dated May 15, 1986, "Response to IE Bulletin 85-03,* C. S. Thomas to Dr. T. E. Murley, Jr.

d) PSNH Letter (NYN-87137) dated November 30, 1987, ' Response to IE Bulletin 85 03,* G. S. Thomas to Mr. V. T. Russell e) Attachment 1 to NRC P.egion I Inspection Report No. 50-443/88-06 dated June 16, 1988, J. T. Wiggins to R. J. Harrison

Subject:

Request for Additional Information to IE Bulletin 85-03

Dear Sir:

Enclosed is the New Hampshire Yankee response to your request as outlined in Reference (e) for additional information with regards to IE Bulletin 85-03.

8807250030 88071L I

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PDR ADOCK 05000443 Q PDC 3 P.O. Box 300 . Seabrook, NH 03874 . Telephone (603) 474 9574

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• n' States Nuclear Regulatory Commission U'ited July 13, 1988 Attention: Document Control Desk Page 2 4

Should you have any questions regarding this information, please contact Mr. Timothy G. Pucko at (603)-474-9574 extension 4428.

Very truly yours, cb George Thomac Enclosure cci Mr. Victor Nerses, Project Manager Project Directorate I-3 Division of Reace.or Projects United States Nuclear Regulstory Commission Washington, DC 20555 Mr. William T. Russell Regional Administrator United States Nuclear Regulatory Commission Region I 425 Allendale Road King of Prussia, PA 19406

-Mr. Antone C. Cerne NRC Senior Resident Inspector Seabrook Station Seabrook, NH 03874 t T wa r # , e.-g- r,._

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l-Enclosuro to NYN- 88097 i: Response to Request for Additional Information for I.E.Bulletin 85-03 The information provided below is in response to the Request for Additional Information regarding IE Bulletin 85-03 as stated in the NRC Inspection Report No. 50-443/88-06.

. REQUEST-

-1. Has water hammer due to valve closure been considered in the determination of pressure differentials? If not, explain.

RESPONSE

Water hammer due to valve closure has not been specifically considered in the detercination of maximum anticipated pressure differentials as described in response to Action Item (a) of IE Bulletin 85-03. The pressure differentials were determined by plaat-specific application using the Weatinghouse methodology as described in the final report of the Westinghouse Owner's Group (WOG) Safety-Related MOV Program dated March, 4 186.

The-Seabrook Station High Head Injection, Intermediate Head Injection and Emergency Feedwater Systems were designed and analyzed not to be susceptible to water hammer conditions. These systems have been tested during the

Seabrook Station Preopers:lonal Test Program. Preoperational tests included testing the high head and intermediate head injection, and emergency feedwater motor-operated valves against maximum practical differential m

, s pressure conditions.- These systems are water solid and subcooled end no water hammer transjents were experienced during preoperational testing. 'The closing times for the high head and intenmediate head injection valves and the emergency feedwater valves that could have a potential for water hammer range from 5.4 seconds to 18.5 seconds. Water hammer requires a sudden

' change in the fluid velocity. The stated valve closure. times are sufficiently slow that a water hammer condition has not been experienced.

i REQUEST l 2 .' If MOVATS is planned for application to some MOVs which are not included in its_ data base, commit to and describe an alternate method for determining l- the extra thrust necessary to overcome pressure differentials for these valves.

j RESPONSE 1

New Hampshire Yankee ( does not intend to use the Motor Operated Valve l

L Analysis and Test f,2:em (MOVATS) data base as justification for switch settings for motor operated valves identified in its response to IE Bulletin 85-03. As stated in reference (c), switch settings were verified using the plant-specific application of the methodology developed by the Westinghouse Owner's Group (WOG). This same methodology was also applied to motor-operators on non-Westinghouse valves. Each valve was subjected to maximum practical differential pressure testing that was performed during preoperational testing. This action verified the design basis for switch settings. Each identified valve was then tested using MOVATS to determine the corresponding thrust values available at the design switch setpoints. This programmatic approach eliminates the dependence on a data base for justification as a design basis for switch settings.

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- i-kEQUEST

3. The AWF HOVs listed for testing in the response of 5/15/86 are shown on Drawings PID FW-B20685 Revision 0, in discharge lines to the steam generators. Verify that'these valvr.s are truly paired in series to each steam generator. Page 27 of the WOG Report of March, 1986, shows them paired in parallel.

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RESPONSE

'i The EFW HOVs (1-FW-FV-4214 A,-B; 1-FW-FV-4224A.-B 'l-FW-FV-4234A.-B and 1-FW-FV-4244A,-B) are installed in series in the discharge lines to the steam generators. PID-1-FW-B20685 correctly represents thic configuration. The WOG report id not a site specific document.

REQUEST

4. On Page 2 of Table I of the response of May 15, 1986, the design closing differential pressure of 850 psig is less than the msximum operating value of 2,530 psig. Justify use of the lower pressure.

REiPONSE As stated on Page 2 of Table 1 (Reference c), the design closing differential pressure for SI-V13G and SI-V139 is 850 psig. These valves are normally closed and must open to meet their designed safety function. The Westinghouse Otraer's Group (WOG) Safety Related MOV Program final report dated March, 1986, Table 3, specified the required maximum operating i

> differential pressure for these valves to close as O psig. A 0 psig ,

differential can be achieved by securing the charging pumps long enough to close the valves. In addition, during preoperational testing, these valves

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'wsre successfully clossd against a 2,700 pound differential pressure. It is possible that the valves could be closed against a 2,530 psig differential pressure (charging pump discharge 2,730 psig minus 200 psig Reactor Coolant System pressure).

REQUEST

5. The proposed program for Action Items b, e and d of the Bulletin is incomplete. Provide the following details as a minimum a) commitment to a training program for setting switches, maintaining valve operators, using signature tes';ing equipment and interpreting signatures, b) commitment to ju tify continued operation of a valve determined to be inoperable (for Unit 1 only).

c) consideration of pipe break conditions as required by the Bulletin.

d) stroke testing when necessary to meet Bulletin requirements.

RESPONSE

a) Seabrook Ste ion operating proced"ras which address preventive and corrective maintenance for motor operated valves have been reviewed and revised where necessary tc ensure that switch settings are correctly determinei and maintained th,ughout the life of the plant. Specific procedural steps and refe rences have been added to include applicable industry recommendations and controls to prevent arbitrary adjustments to torque, torque by-pass, limit, permissive and position indicating switches. The setting criteria and prerequisite reviews are specified in both the reference and functional sections of the procedures.

Maintenance individuals who perform these adjustme-nts are trained in

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_accordence with the Ss brook Station opsrating procsdures. The training program consists of an organized classroom session in conjunction with 1

actual hands on training in the training facility.

i Seabrook Station operating procedures were developed to define a site-specific application for MOVATS testing of motor operated valves. These procedures were written in a step by step format and require a second person verification'of the steps that are determined to be critical to proper signature acquisition.

The testing is conducted by individuals in the Maintenance and/or System Support Departments. At least one individual in each test situation has been qualified by demonstrating the successful completion of the Station Training Program Course in 'MOVATS-Data Acquisitions".

Test results and signatures are reviewed by System Engineers who have been qualified in MOVATS testing and analysis. This qualification program requires successful compl.ai0n of two training courses -

"Limitorque Valve Actuator Overhaul" and 'MOVATS-Data Acquisition and/or MOVATS-Signature Analysis."

The System Engineers evaluate the test results and are responsible for any outstanding follow-up action. In addition to the data review, System Engineers also perform periodic surveillances of field testing.

e b). HOVATS tssting is parformtd on valvas that havs baan takan out of service for corrective maintenance, or as part of a routine outage for surveillance, inspection, or preventive maintenance. When this occurs the affected portion of the system involved is declared inoperable in accordance with Technical Specifications. If, as a result of MOVATS testing, a condition is discovered that requires corrective action, appropriate steps are taken to evaluate the problem, root cause, reportability, and the action / retests required for return to service.

This is accomplished prior to declaring the valve and the affected portion of the system operable in accordance with established Station programs, procedures, and Technical Specifications, c) The maximum differential pressures postulated for pipe' break conditions are considered in the data presented in Table 1 of Reference (c). The analysis performed for Table 1 of Rafarence (c) derived the maximum differential pressures usitig system specific criteria including the following, as applicable:

1) Dead head pump discharge pressures.

ii) Maximum tank level head pressure.

iii) System pressures due to abnormal line-up.

iv) Zerc pressure in the Reactor Coolant System.

v) Zero pressure in a steam generator.

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if) lAs stated in response to Request 2 above, orch valva was initially subjected to a test at maximum practical differential pressure and the y

resultant switch settings documented. These switch settings have been correlated to actual thrust values available to seat and unseat these valves. This correlation was performed by obtaining a diagnostic signature analysis using the MOVATS system. Retests to verify operability will be performed in accordance with the ASME Section XI requirements. The use of a new diagnostic sigr,.vv.e analysis test will be performed when applicable to ensure that the post maintenance settings are adequate.

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