ML20113B278

Forwards Util USI A-46 Seismic Evaluation Rept Vols I/V & USNRC USI A-46 Resolution Ssel & Relay Evaluation Rept for April 1996 Vol I of Viii

ML20113B278
Person / Time
Site:	Cooper
Issue date:	06/13/1996
From:	Horn G NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20113B280	List: ML20113B278 ML20113B283 ML20113B289 ML20113C192
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, NLS960076, NUDOCS 9606270032
Download: ML20113B278 (6)

Text

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r. GENERAL OFFICE P.o. BOX 499, COLUMBUS. NEBRASKA 68602-0499 Nebraska Public Power District Tu % f& T l G. R. HORN Senior Vice-President, Energy Supply (403) 563-5618 NLS960076 June 13,1996 i

U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Submittal of the Unresolved Safety Issue (USI) A-46 Summary Report Cooper Nuclear Station, NRC Docket No. 50-298, License No. DPR-46

References:

See Attachment 1 Gentlemen:

Background

In Generic Letter (GL) 87-02 (Reference 1), dated February 19,1987, the Nuclear Regulatory Commission (NRC) set forth the process for resolution of USI A-46 and encouraged utilities to participate in a generic program. In Supplement 1 to GL 87-02 (Refereace 2), dated May 22, 1992, the NRC requested a response to include a commitment to the Generic Implementation Procedure, Revision 2, GIP-2 (Reference 3), prepared by the Seismic Qualification Utility Group (SQUG), a schedule for the implementation of the GIP, and a report suminarizing the results of the USI A-46 Program. By letter dated September 21,1992 (Reference 4), the Nebraska Public Power District (District) responded to Supplement 1 of Generic Letter 87-02. Our response included a commitment to implement GIP-2, including the clarifications, interpretations, and exceptions in Supplemental Safety Evaluation Report (SSER-2). Our response c.lso included a commitment to communicate to the NRC any significant or

. programmatic deviations from the GIP guidance. Other major correspondences related to the j District's response to Generic Letter 87-02, Supplement 1 (Reference 2), include References 5,  !

6, and 7. l The District has completed the USI A-46 evaluation for Cooper Nuclear Station (CNS) through the implementation of the SQUG GIP (Reference 3). This letter forwards the results of this evaluation and confirms that no significant or programmatic deviations from the GIP guidance l were made during the USI A-46 resolution process. The attachments to this letter contain the l detailed results of the evaluation, along with a description of the outliers that were identified.

Additional detail regarding the attachments is provided below.

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i U.S. Nuclear Regulatory Commission June 13,1996

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l USI A-46 Reports I

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GIP-2, Part I, Section 2.2.8 specifies that a plant-specific Summary Report is to be submitted to the NRC, including a proposed schedule for future modifications and replacements of those outliers which are yet to be resolved. GIP-2, Part II, Section 9 provides details regarding the contents of this Report which includes the Safe Shutdown Equipment List (SSEL), Relay

. Evaluation, Seismic Evaluation, and the Completion letter. This submittal constitutes the CNS l Plant Specific Summary Report. Attachment 2 consists of the USI A-46 Seismic Evaluation Report. Attachment 3 consists of the USI A-46 Resolution SSEL and Relay Evaluation Report.

l Also attached (Attachment 4) is " Generation of Conservative Design and Median-Centered In-

Structure Response Spectra for the Cooper Nuclear Station Plant Control and Reactor Buildings," by EQE International. This report is identified as Reference 12 in the USI A-46 Seismic Evaluation Report. Attachment 4 contains floor response spectra using modern soil-l structure interaction techniques. In the USI A-46 seismic evaluations, the median-centered spectra contained in this report were used only to resolve two raceway outliers. All other USI A-46 seismic evaluations used the floor response spectra previously submitted to the USNRC in response (Reference 4) to Supplement 1 to Generic Letter 87-02.

j Outliers l Outliers, as defined by GIP-2, were identified during the seismic and relay reviews and are i

described in detail in Attachment 2. The SSEL outliers are identified in Attachment 3.

l The outliers have been evaluated against the existing CNS licensing and design bases for

- equipment seismic qualification. The District has determined that there are no operability concerns associated with these outliers.

The District is continuing to evaluate these outliers in accordance with the guidelines set forth

!' -in GIP-2. . It should be noted that the description for each of the outliers identified in the attachments to this letter is accompanied by a proposed resolution summary. These proposed resolutions are based on the best information available at this time, and are being provided for l information purposes only. As more information becomes available, the resolutions may l change.

i Schedule for Outlier Resolution I The District will resolve as many of the outliers as possible prior to the conclusion of Refueling Outage No.17 (RE-17). However, there are several factors that the District realistically expects to impact the RE-17 completion goal. These factors include, but are not limited to, the

.. development and approval of the design changes needed to correct the subject outliers prior to

the internal scheduling deadline for RE-17 and availability of resources for detailed analytical evaluations and/or modification development and implementation. However, all of the outliers will be resolved by the end of RE-18, which is currently scheduled to commence October 1998.

The RE-18 deadline will allow the District to respond to any complications that could arise through the outlier resolution process. As per the guidelines of GIP-2, the District will submit a

' completion letter no later than 60 days after all of the remaining outliers have been resolved.

i U.S. Nuclear Regulatory Commission June 13,1996 Page 3 of 4 Licenalna Basis Modification I

The District is currently evaluating the need to expand the CNS licensing basis to include the use of the USI A-46 methodology, as documented in GIP-2 and SSER-2, as an option for verifying the seismic adequacy of the electrical and mechanical equipment classes covered by GIP-2 (maintenance of the SSEL). In part, this decision will be based on the results contained in the Safety Evaluation Report pertaining to the NRC's closure of USI A-46 for CNS. 1 l

Additionally, the District is considering the use of the USI A-46 methodology for new and replacement equipment as described in GIP-2, Part I, Section 2.3.4. Should the District elect to adopt the GIP methodology for either the maintenance of the SSEL and/cr for the evaluation of new and replacement equipment, the District will inform the NRC of such decisions in a separate letter. l Should you have any questions or require any additional information, please contact me.

Sincerely,

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l G rn

-Fen r Vice President, Energy Supply l /dnn:

Attachments (1) References j l (2) USI A-46 Seismic Evaluation Report for CNS

! (3) USI A-46 Resolution SSEL and Relay Evaluation Report for CNS (4) EQE Report, " Generation of Conservative Design and Median-Centered In-Structure Response Spectra for the Cooper Nuclear Plant Control and Reactor Buildings" '

cc: Senior Project Manager USNRC - NRR Project Directorate IV-1 l

Senior Resident Inspector USNRC - Cooper Nuclear Station Regional Administrator USNRC - Region IV SQUG Steering Committee NPG Distribution (Attachment 1 only) l I

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I U.S. Nuclear Regulatory Commission I June 13,1996 i Page 4 of 4 l

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l STATE OF NEBRASKA )

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PLATTE COUN TY )

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' l G. R. Horn, being first duly sworn, deposes and says that he is an authorized representative of l l the Nebraska Public Power District, a public corporation and political subdivision of the State l

! of Nebraska; that he is duly authorized to submit this response on behalf of Nebraska Public Power District; and that the statements contained herein are true to the best of his knowledge and beli .f.

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Subscribed in my presence and sworn to before me this Iday of O ltr L ,1996.

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NOTARY FUBLIC r toes.Eiset i 1

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Attachment I to NLS960076 Page1of1 I

References:

1) Generic Letter 87-02, dated February 19,1987, " Verification of Seismic l Adequacy ofMechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46" 4 I

l 2) Generic Letter 87-02, Supplement 1, dated May 22,1992, " Generic Letter ,

l that transmits to Licensees the Supplemental SER to the GIP, Revision l 2, as corrected on February 14,1992" l 3) SQUG Procedure, " Generic Implementation Procedure (GIP) for Seismic Verification of Nuclear Plant Equipment," Revision 2, corrected 02/14/92 l 4) Letter (No. NSD921004) to USNRC Document Control Desk from G. R.

l Horn (NPPD), dated September 21,1992, " Response to Supplement 1 to Generic Letter 87-02"

5) Letter to G. R. Horn (NPPD) from USNRC, dated November 25,1992, l " Evaluation ofLicensee's 120-Day Response to Supplement 1 to GL 87-02 for CNS (TAC No. M69439)"

6) Letter (No. NSD930262) to USNRC Document Control Desk from G. R. ,

Horn (NPPD), dated February 24,1993," Clarification of the Response to l Generic Letter 87-02, Supplement 1"

7) Letter to G. R. Horn (NPPD) from K. A. Connaughton (USNRC), dated July 26,1993, " Evaluation of Licensee's Supplemental Response to Supplement 1 to GL 87-02 for CNS (TAC M69439)"

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, LIST OF NRC COMMITMENTS ATTACHMENT L 3 l Correspondence No: NLS96007(

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The following table identifies those actions committed to by the District in thic document. Any other actions discussed in the submittal represent intended or planned actions by the District. They are described to the NRC for the NRC's l- information and are not regulatory commitments. Please notify the Licensing Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.

COMMITTED DATE COMMITMENT OR OUTAGE l All of the outliers will be resolved by the end of RE-18, Conclusion of RE-18 which is currently scheduled to commence October 1998.

The District will submit a completion letter after all of 60 days beyond the the remaining outliers have been resolved. conclusion of RE-18.

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l PROCEDURE NUMBER 0.42 l REVISION NUMBER 1 l PAGE 9 OF 11 l

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