ML20151C037

Forwards Suppl to Re Plant Diesel Generators. Suppl Replaces Item 4, Tests on Diesel Generators & Clarifies Ltr Concerning Tests Required by Reg Guide 1.108

ML20151C037
Person / Time
Site:	Sequoyah
Issue date:	03/28/1988
From:	Kusko A, Peeran S FAILURE ANALYSIS ASSOCIATES, INC.
To:	Marinos A NRC
Shared Package
ML20151C007	List: ML20151C004 ML20151C037
References
RTR-REGGD-01.108, RTR-REGGD-1.108 NUDOCS 8804120105
Download: ML20151C037 (2)

Text

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March 28, 1988 SUPPLEMENT TO OUR LETTER DATED MARCH 25, 1988

4. Tests on The Diesel Generators Mr. Hicks disbelieves the licensee's claim that full load testing of the diesel generators is not practical and thinks that the licensee did not perform the full load test because the diesel generator is undersized and is not capable of handling the full load. Testing of the diesel generator is specified in Reg. Guides 1.108 and 1.9. Reg. Guide 1.108 specifies the following:

1. Nine tests on each diesel during the plant preoperational test program and at least, once every 18 months (Section 2.a (1) - (9))

2. One test in which redundant diesel generators are started simultaneously. This test is performed during the preoperational test program and subsequent to any plant modification or every ten years (Section 2.b)

3. Two periodic tests on each diesel generator during plant normal operation at intervals of 31 days (Section 2.c) or as specified in Section 2.d.

Section 2.a. (3) requires that the diesol generator must be tested to "Demonstrate full-load-carrying capacity for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of which 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> should be at a load equivalent to the continuous rating of the diesel generator and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a load equivalent to the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> rating of the diesel maintained. The test should also verify that the cooling system functions within design limits." We understand that this test has been performed by the licensee. Documentation should be available with the licensee and th6 NRC.

Test specified in Section 2.a.(2) of Reg. Guide 1.108 should "Demonstrate proper operation for accident-loading-sequence to design-load requirements and verify that voltage and frequency are maintained within the required limits". These limits are specified in Reg. Guide 1.9. The voltage and frequency should not reduce belov 75 percent and 95 percent, respectively, of the nominal values during the sequential loading. This test was performed by the licensee during the period June - November 1987.

During the test the various pump motors which were started in sequence could not be loaded to their full power ratings because of the lack of full-flow bypasses. The licensee submitted calculations to apply corrections to the test results to reflect the design-accident loading, in January and February 1988. We have reviewed these calculations. The worst case voltage margine for sustaining the 6.6-kV and 4 80-V motors are adequate. The calculated voltage during the sequential loading satisfies the requirements of the Reg. Guide 1.9 Oh P P

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, C' s- e 8 j%, UNITED STATES

[ 'g NUCLEAR REGULATORY COMMISSION  !

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APR 0 6 %88 MEMORANDUM FOR: Chairman Zech Comissioner Roberts Comissioner Ger:1 thal Comissioner Carr Comissioner Roger 5 FROM: Victor Stello, Jr.

Executive Director for Operations

SUBJECT:

SUPPLEMENT TO CONSULTANTS' REVIEW ON DIESEL GENERATORS AT SEQUOYAH l The attached letter was received after I had forwarded the consultants' initial report to you on April 4, 1988. This lettar supplements the  ;

March 25, 1988 letter and replaces item 4 of that letter entitled "Tests on Diesel Geiterators."  :

, (Sign?d) T. A. Rehm

/

hiictorStello,Jr. i 4

Executive Director for Operations  ;

Enclosure:

March 28, 1988 letter i j from A. Kusko and S. Peeran

cc

P. Gwynn (COMLZ)

~ C. Ader (COMTR)

C. Miller (COMFB)

T. Elsasser (COMKC) a J. Scarborough (COMKR)

SECY OGC OCA M. Callahan

) DISTRIBUTION Docket File (50-347/328) ED0 R/F JClifford SEbneter NRC PDR OSP Reading SRichardson VStello Local POR TVA Reading JAxelrad

, EDO ED0 T Re hre'v'C VStello 4/6 /88 4/ /88

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