ML20056G430

Safety Evaluation Re Inservice Testing Program Requests for Relief.Licensee Made Changes to Subj Program to Include Exercising & fail-safe Testing of Auxiliary Feedwater Valves AF-6451 & AF-6452,in Response to TER Anomaly 8

ML20056G430
Person / Time
Site:	Davis Besse
Issue date:	08/18/1993
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20056G424	List: ML20056G423 ML20056G430
References
GL-89-04, GL-89-4, NUDOCS 9309030110
Download: ML20056G430 (3)

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,/ WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM RE0 VESTS FOR RELIEF

, TOLEDO EDISON COMPANY M RIOR SERVICE COMPANY i

b.ND THE CLEVELAND ELECTRIC ILLUMINATING COMPANY l DAVIS-BESSE NUCLEAR POWER STATION. U_ NIT NO. 1 l

DOCKET NO. 50-346

1.0 INTRODUCTION

The Code of Federal Regulations,10 CFR 50.55a, requires that inservice

. testing (IST) of certain American Society of Mechanical Engineers (ASME) l Boiler and Pressure Vessel Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the Code and applicable addenda, i

except where relief has been requested and granted or proposed alternatives ,

have been authorized by the Commission pursuant to 10 CFR 50.55a(f)(6)(1),

(a)(3)(i), or (a)(3)(ii). In order to obtain authorization or relief, the licensee must demonstrate that: (1) conformance is impractical for its facility; (2) the proposed alternative provides an acceptable level of quality and safety; or (3) compliance would result in a hardship or unusual difficulty l without a compensating increase in the level of quality and safety. Section j 50.55a(f)(4)(iv) provides that inservice tests of pumps and valves may meet i the requirements set forth in subsequent editions and addenda that are  !

incorporated by reference in 10 CFR 50.55a(b), subject to the limitations and modifications listed, and subject to Comission approval. NRC guidance contained in Generic Letter (GL) 89-04, " Guidance on Developing Acceptable Inservice Testing Programs," provided alternatives to the Code requirements t determined to be acceptable to the staff and authorized the use of the alternatives in Positions 1, 2, 6, 7, 9, and 10 provided the licensee follow the guidance delineated in the applicable position. When an alternative is

, proposed which is in accordance with Generic Letter (GL) 89-04 guidance and is l documented in the IST program, no further evaluation is required; however, implementation of the alternative is subject to NRC inspection. I Section 50.55a authorizes the Comission to grant relief from ASME Code requirements or to approve proposed alternatives upon making the necessary findings. The NRC staff's findings with respect to granting or not granting the relief requested or authorizing the proposed alternative as part of the licensee's 15T program are contained in this Safety Evaluation (SE).

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In rulemaking to 10 CFR 50.55a effective September 8, 1992, (57 FR 34666), the 1989 edition of ASME Section XI was incorporated in 10 CFR 50.55a(b). The 1989 edition provides that the rules for IST of pumps and valves shall meet the requirements set forth in ASME Operations and Maintenance Standards Part 6 (OM-6), " Inservice Testing of Pumps in Light-Water Reactor Power Plants," and Part 10 (OM-10), " Inservice Testing of Valves in Light-Water Reactor Power Plants." Pursuant to 10 CFR 50.55a(f)(4)(iv), portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met, and subject to Commission approval. Because the f

alternatives meet later editions of the Code, with NRC approval, relief is not l required for those inservice tests that are conducted in accordance with OM-6 and OM-10, or portions thereof, provided all related requirements are met.

Whether all related requirements are met is subject to NRC inspection.

2.0 BACKGROUND

Toledo Edison (the licensee), in their letter dated April 8,1993, responded to an anomaly identified in NRC's Safety Evaluation (SE) of December 2,1991, related to a relief request for the Davis Besse Nuclear Power Station, Unit 1, Inservice Testing (IST) Program for pumps and valves, second 10-year interval.

The submittal provided the licensee's response to one of the anomalies found in the Technical Evaluation Report (TER) attached to the SE. The anomaly identified in TER Appendix B, as Anomaly No. 8 concerned TER Section 3.2.1.1 regarding the licensce's request for relief from measuring stroke times for auxiliary feedwater valves AF-6451 and AF-6452. The licensee proposed to exercise and fail-safe test these valves quarterly, but not record stroke times. The SE granted interim relief to allow the licensee to develop a method to monitor the valves for degradation.

In the SE, the NRC staff requested that the licensee resolve the anomalies associated with the relief requests and implement program / procedures changes a: needed. The other anomalies identified in the TER were addressed in TE's letter dated July 8,1992, and evaluated in the NRC SE dated April 23, 1993.

2.1 LICENSEE RESPONSE TO ANOMALY NO. 8

The licensee states:

AF-6451 and AF-6452 are Target Rock solenoid operated valves with position indication from linear variable differential position transmitters. The valve actuator is a closed cylinder containing the upper valve stem, a solenoid positioner, and stem position instru-mentation. The valve position cannot be directly observed. Valve stroke time is dependent on system flow rates. An indirect indication of stroke time can be obtained by measuring the time from a valve-open signal until a predetermined voltage from the linear variable differential position transmitter indicates the valve is fully open.

Stroke time will be determined quarterly by indirectly measuring the stroke time under no flow conditions using this method.

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2.2 EVALUATION

! The licensee revised the IST Program to incluce quarterly stroke time measurement and fail-safe testin; for valves AF-6451 and AF-6452. The stroke times will be obtained indirectly using output voltage from the linear variable differential position t ansmitter at no flow. Position indication and fail-safe position will be verified using system flow each quarter. The

ASME Bof 7er and Pressure Vesse? Code,Section XI, Paragraph IW-3412 (b),

l requires valve disk movement be determined by exercising the valve while observing an appropriate indicator which signals the required change of disk position, or by observing indirect evidence. Paragraph IW-3413 (a) states that the full-stroke time is the time interval from initiation of the actuating signal to the end of the actuating cycle. The licensee's proposed t alternative meets the intent of the Code.

2.3 CONCLUSIQH l

l The NRC staff requested the licensee to resolve the anomalies associated with the relief requests contained in the NRC SE and attached TER dated December 8, l 1991, and implement program and procedures changes as needed. The licensee's response was completed by letter dated April 8,1993, which addressed TER Anomaly 8. To address the anomaly, the licensee made changes to the IST Program to include exercising, stroke timing, and fail-safe testing of auxiliary feedwater valves AF-6451 and AF-6452. The NRC staff has evaluated the changes and finds that they meet the intent of the ASME Code,Section XI requirements, and are acceptable.

Principal Contributor: F. T. Grubelich Date: August 18, 1993