ML12202A013

Revision to a Response to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11

ML12202A013
Person / Time
Site:	Calvert Cliffs
Issue date:	07/18/2012
From:	George Gellrich Constellation Energy Nuclear Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML12202A013 (5)

Text

George H. Gellrich Calvert Cliffs Nuclear Power Plant, LLC Vice President 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.5200 410.495.3500 Fax CENG.

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%0Energyý CALVERT CLIFFS NUCLEAR POWER PLANT July 18, 2012 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos. I & 2; Docket Nos. 50-317 & 50-318 Revision to a Response to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11

REFERENCES:

(a) Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated August 8, 2011, License Amendment Request: Diesel Generator Surveillance Requirement 3.8.1.11 Revision (b) Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated January 11, 2012, Responses to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11 In Reference (a), Calvert Cliffs Nuclear Power Plant, LLC submitted a license amendment request to revise Technical Specification Surveillance Requirement 3.8.1.11 by revising the required power factor value to be achieved by the diesel generators during conduct of the surveillance test. In Reference (b),

Calvert Cliffs responded to the Nuclear Regulatory Commission's request for additional information (RAI) to support their review of Calvert Cliffs' license amendment request. Attachment (1) provides a revision to our response to RAI #2 which replaces the response originally provided for RAI #2 in Reference (b). The revision is denoted by a revision bar in the right-hand margin.

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Document Control Desk July 18, 2012 Page 2 Should you have questions regarding this matter, please contact Mr. Douglas E. Lauver at (410) 495-5219.

Very truly yours, STATE OF MARYLAND

TO WIT:

COUNTY OF CALVERT I, George H. Gellrich, being duly sworn, state that I am Vice President - Calvert Cliffs Nuclear Power Plant, LLC (CCNPP), and that I am duly authorized to execute and file this License Amendment Request on behalf of CCNPP. To the best of my knowledge and belief, 'the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other CCNPP employees and/or consultants. Such information has been reviewed in accordance with company practice and I believe it to be reliable.

Subscribed and sworn before me. a Notary Puic in and for the State of Maryland and County of

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Attachment:

(1) Calvert Cliffs Revised Response to NRC Request for Additional Information #2 cc: N. S. Morgan, NRC Resident Inspector, NRC W. M. Dean, NRC S. Gray, DNR

ATTACHMENT (1)

CALVERT CLIFFS REVISED RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION #2 Calvert Cliffs Nuclear Power Plant, LLC July 18, 2012

ATTACHMENT (1)

CALVERT CLIFFS REVISED RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION #2 This response to Request for Additional Information (RAI) #2 replaces our previous response to RAI #2 that was submitted on January 11, 2012 (Reference 1).

NRC RAI #2:

SR 3.8.1.11 requires testingfor > 60 minutes to ensure the DG's ability to perform its safety function.

However, operating experience at some plants with 24-hour surveillance times has identified some weaknesses in the DG systems which would not have been identified if the SR was performedfor a lesser duration. Regulatory Guide 1.9 also recommends testing of emergency DGs for 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> at nominal rating and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at the short term overload capability.

Providejustficationfor not adopting the currentregulatoryguidancefor DG testing.

CCNPP Response #2:

Although not part of Calvert Cliffs' Technical Specifications, there are times when the DGs are run for greater than a one hour period. They include:

" Performances of a four hour run of each DG approximately every two years. This is generally done following performance of a major engine inspection of the DGs.

" Performance of a bearing run-in on the IA DG approximately every eight years. This run requires approximately 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> of operation at various loads, up to full load.

" Performance of a multi-hour run when a main bearing on one of the three Fairbanks Morse DGs is disturbed.

• Performances of a four hour run if any of the Fairbanks Morse DGs are started without pre-lubrication.

" Performance of an extended run following DG maintenance as part of the post-maintenance testing plan. The test runs and durations are determined based on the scope and nature of the maintenance performed. An extended run provides the opportunity to identify any latent failure mechanism that may be introduced during maintenance. In fact, following recent maintenance, one of the DGs was run for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as part of the post-maintenance testing.

While we believe there is a benefit to performing appropriate testing following DG maintenance, including endurance runs, we also consider that the testing scope and duration should be based on the maintenance activities performed. This could result in testing up to a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration run, as well as shorter runs.

On several occasions the Surveillance Requirements for the DGs have been reviewed and approved, by the Nuclear Regulatory Commission. This includes Reference 2, which approved a revised electrical plant distribution configuration and the Surveillance Requirements and Limiting Conditions for Operation for our new safety related DG (DG IA). Later, during Calvert Cliffs' transition to Improved Technical Specifications, the DG Surveillance Requirements were again reviewed, but not changed (Reference 3).

Note that this amendment request is to correct an existing, non-conservative error by aligning the power factor value listed in Surveillance Requirement 3.8.1.11 to the power factor contained in the design calculation. We are not seeking a voluntary change to the licensing basis; rather we have submitted this change in accordance with Reference 4.

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ATTACHMENT (1)

CALVERT CLIFFS REVISED RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION #2 REFERENCES

1. Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated January 11, 2012, Responses to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11

2. Letter from D. G. McDonald (NRC) to C. H. Cruse (CCNPP), dated April 2, 1996, Issuance of Amendments for Calvert Cliffs Nuclear Power Plant (Amendments 214, Unit I and 191, Unit 2)

3. Letter from A. W. Dromerick (NRC) to C. H. Cruse(CCNPP), dated May 4, 1998, Issuance of Amendments for Calvert Cliffs Nuclear Power Plant (Amendments 227, Unit I and 201, Unit 2.)

4. NRC Administrative Letter 98-10, dated December 29, 1998, Dispositioning of Technical Specifications That are Insufficient to Assure Plant Safety 2