ML20070H614

Forwards 120-day Response to Suppl 3 to Generic Ltr 89-10, Consideration of Results of NRC-Sponsored Tests of Motor-Operated Valves. Recommended Torque Switch Adjustment Will Be Performed Prior to Startup from Outage 5

ML20070H614
Person / Time
Site:	Grand Gulf
Issue date:	03/08/1991
From:	Cross W ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-10, GNRO-91-00048, GNRO-91-48, NUDOCS 9103140321
Download: ML20070H614 (5)

Text

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1 March 8, 1991 U.S. Nuclear Regulatory Commission Mai1 Station P1-137 Washington, D.C.

20555 Attention:

Document Control Desk

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 120 Day Response to Generic Letter 89-10, Supplement 3 GNRO-91/00048 Gentlemen:

The NRC issued Supplement 3 to Generic Letter 89-10, " Consideration of the Results of NRC-Sponsored Testa of Motor Operated Valves," to all licensees on October 25, 1990 (MAEC-90/0277).

This supplement concerned test data from the Idaho National Engineering Laboratories (INEL) Motor Operated Valve (MOV) testing program which e.uggested that deficiencies may exist in MOVs in the RCIC, HPCI, PWCU and Isolation condenser systems of BWR fac!11tles.

In order to determine if deficiencies did exist, each licensee was requested to perform a safety assessment of the isolation valves in the specified systems considering design, operating, and maintenanco factors presented in Supplement 3.

in response, Entergy Operations, Inc. submitted the results of a safety assessment on December 11, 1990 (AECM-90/0217) for the Grand Gulf Nuclear Station (GGNS). The safety assessment concluded that the as-installed configurations of the applicable leolation valves were adequate. Thin conclusion was premised on the specified h0Vs having a thrust capacity exceeding that predicted using INEL data or an evaluation which demonstrated that an MOV with less than predicted thrust capability does not reprasent a significant safety concern. GGNS also evaluated the thrust capability of MOVs la other systems and, for those systems reviewed, identified no conditions detrimental to valve functionality.

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March 8, 1991 GNRO-91/00048 Page 2 of 3 Supplement 3 also requested a 120 day response providing the critoria used to evaluate the capacity of the subject MOVs, identify!ng any MOV not meeting these criteria, and establishing a schedule for any corrective action required. This requested information is provided in the Attachment. Recommended torque switch adjustments as noted in the Attachment will be performed prior to start-up following the next refueling outage, RF05.

This outage is currently scheduled to begin in April, 1992.

If you require additional information, please advise.

Yours truly, ad C' WTC/WKH/ams attachment:

Evaluation Criteria, Results, and Schedule cc:

Mr. D. C. Illntz (w/a)

Mr. J. Mathis (w/a)

Mr. R. B. McGehee (w/a)

Mr. N. S. Reynolds (w/a)

Mr.11. L. Thomas (w/o)

Mr. F. W. Titus (w/a)

Mr. Stewart D. Ebneter (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30323 Mr. L. L. Kintner, Project Manager (w/a)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 11D21 Washington, D.C.

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~ BEFORE Tile -

UNITED STATES NUCLEAR REGULATORY COMMISSION-LICENSE NO. NPF-29 i

DOCKET NO. 50-416 IN THE; MATTER OF i

MISSISSIPPI POWER & LIGitT COMPANY-and l

SYSTEM ENERGY RESOURCES, INC.

and SOUTH MISSISSIPPI ELECTRIC POWEP ASSOCIATION and ENTERGY OPERATIONS, INC.

AFFIRHATION l

I, W. T. Cottle, being duly sworn, state that I am Vice President, Operations GGNS of Entergy Operations, Inc. ; that on behalf of Entergy i

Operations, Inc., System Energy Resources,eInc., and-South Mississippi l

Electric Power Association I am authorized by Entergy Operations, Inc, to sign and file with the-Nuclear-Regulatory Commission, this Response to e

Generic Letter.89-10, Supplement 3; that I signed this letter as,Vice President, Operations GGNS of Entergy Operations, Inc.; and that the r

statements made and the matters set forth therein are true and correct to t h best of my knowledge, information and_ belief.

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c. 4 D h Wi-.T. Cottle-STATE OF MISSISSIPPI l

COUNTY OF CLAIBORNE l

SUBSCRIBED AND SWORN T0 before me, a Notary Public, d.n and for the County j-and State above named, this day of Desnph 1991.-

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(SEAL)

A.hykoh C

Notary: Pub ic My commisalon expires:

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t Attachment to GNRO-91/00048-i

$20 Day Response to Generic Letter 89-10. Supplement _3 l

Eya_luation Criteria. __Results, and Schedule 4

CRITERIA:

INEL test data was reviewed for applicability to the GGNS RWCU_and RCIC steam supply isolation valves. As a result of the review,'it was considered appropriate for'the purpose of the immediate' assessment required by Supplement 3 to consider the 'results.of the INEL 10" William l

Powell flex wedge gate valve. test to be applicable to the two GGNS RCIC 10" William Powell flex wedge gates. _ It is _ recognized, however, that similarity cannot necessarily be establishad. based on vendor, type, and size alora. None of the INEL data is considered to apply to_the RWCU 6" William Fowell flex wedge gate valves sin" William PoweF1 gate-valves were-tested.

Based on the above application of the INEL testing and subsequent.

l industry sponsored evaluations, GGNS concludes that in the absence of valve specific test data for the subject MOVs, actuators should be sized i

utilizing a disk factor of 0.5 sir blowdown. isolation conditions are postuinted. Where valve specific blow.own test. data is available,-it-should be used.

These criteria shoula be. applied in conjunccion_with material limits and-degraded voltagr conditions.

RESULTS:

Applying the above criteria to the subject MOVs, it is ' concluded that-all-j have adequate capacity to isolate against postulated' blowdown flows.

However the current torque switch. setting for two MOVs will-require-.

l adjustment or confirmation that sufficient delivered thrust results.-

These MOVs are identified as E51F063, the inboard RCIC steam 1 supply--

l 1 solation _ valve, and.G33F251, the-outboard RWCU post-pump mode supply.

- i isolation valve.

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-E51F063 is a 10" William Powell_ gate valve similar in' size,1 type, and manufacturer to_that tested by INEL.

The valve is equipped with an SMB-1 actuator and's 40 ft-lb motor.

Field measurement =of delivered-thrust during the last refueling outage indicates itLto be less than that-

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required during the INELLtest.

This-condition was previously evaluated-with acce.ntabic conclusions as stated in the december 11, 1990, GGNS

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submittal (AECM-90/0217). However,. torque switch settings.will be i

adjusted accordingly during RF05.

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Due to the Mark III, BWR/6 design, it was not necessary to address ~HPCI.

. i system or isolation condenser-in the safety assessment and this response.

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J Attachment to GNRO-91/00048 G33F251 is a 6" William Powell gate valve driven by an SMB-0 actuator with a 25 ft-lb motor.

This type valve was not tested by INEL and was therefore evaluated using a disk factor of 0.5.

No field measurement of delivered thrust is currently available but the switch setting recorded for the closing direction during the last refueling outage closely corresponds to the recorded setting for three other identical RWCU MOVs for which delivered thrust is known.

In all three cases delivered thrust exceeds that required to support the use of a 0.5 disk factor.

Based on this comparison, it is believed that torque switch setting for G33F251 is also adequate.

However, delivered thrust will be measured in RF05 and any necessary torque switch adjustments will be made.

The above measures are considered adequate until more applicable flow test data becomes available during the course of implementing the recommendations of Generic Letter 89-10.

This is consistent with the "two stage" approach recommended by the NRC.

SCHEDq'.:

The noted torque switch adjt stments will be performed as necessary during RF05, currently scheduled to begin in April, 1992.

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