ML20128D523

Safety Evaluation Accepting 120-day Response to Suppl 1 to Generic Ltr 87-02, Verification of Seismic Adequacy of Mechanical & Electrical Equipment in Operating Reactors,Usi A-46,

ML20128D523
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	11/25/1992
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20128D492	List: ML20128D490 ML20128D523
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, NUDOCS 9212070297
Download: ML20128D523 (4)

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l E MCLOSVRE 1 SAFETY EVALVATION BY THE Off!CE OF NUCLLAR REACTOR RIEVLATION LVALVATION OF THE 120-DAY RESPONSE TO SVPPLEMENT NO. 1 TO GENERIC LETTER 87-02 Mif{ECTICVT YANKEE ATOMIC POWER COMPANY HAC3AM NECK PLANT DOCKET NO. 50-213 MCIE0EQ By letter dater.' September 21, 1992, the Connecticut Yankee Atomic Power Company (CYAPC0, the licensee ) submitted its response to Supplement No. I to Generic Letter 87-02 (GL 87-02), Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (VSI) A-46," dated May 22, 1992, for the Haddam Neck Plant. In Supplement No, I to GL 87-02, the staff requested that affected licensees submit the following information within 120 days of the issue date of the supplement:

1. A statement whether you commit to use both the seismic Qualification Utility Group (SQ'JG) commitments and the implementation guidance provided in the Generic Implementation Procedure, Revision 2 (GlP-2) as supplemented by the staff's Supplemental Safety Evaluation Report No. 2 (SSER-2) for the resolution of USl A-46. In this case, any deviation from GlP-2, as supplemented by the SSER No. 2, must be identified, justified, and documented. if you do not make such a commitment, you must provide your alternative for responding to GL 87-02.

2. A plant-specific schedule for the implementation of the GIP and submission of a report to the staff that summarizes the results of the VSl A-46 review, if you are committing to implement GIP-2. This schedule shall be such that each affected plant will complete its implementation and submit the summary report within 3 years after the issuance of the SSER No. 2, unless otherwise justified.

3. The detailed information as to what procedures and criceria were used to generate the in-structure response spectra to be used for VSl A-46 as requested in the SSER No. 2. The licensee's in-structure response spectra are considered acceptable for USI A-46 unless the staff indicates otherwise during a 60-day review period.

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I f 2-In addition, the staff requested in SSER No. 2 that the licensees inform the staff in the 120-day response if they intend to change their licensing basis to reflect a commitment to the US! A-46 (GlP-2) methodology for verifying the seismic adequacy of mechanical and electrical equipment, prior to receipt of the staff's plant-specific safety evaluation resolving USI A-46.

LVALVATid With regard to item 1, the Itcensee stated that, "CYAPC0 intend [sg to comply with the 500G commitments set forth in Revision 2 of the GIP, inc uding the clarifications, interpretations, and exceptions identified in SSER-2 in order to satisfy GL 87-02." The staff recognizes that the licensee has chosen to implement GIP-2, including both the SQUG commitments and the implementation guidance, for responding to GL 87-02. The staff finds that this it an acceptabic method to resolve USl A-46 at the Haddam Neck Plant.

The licensee indicated that it plans to use existing anchorage evaluations, which were performed as part of the Systematic Evaluation Program at Haddam Neck Plant, as justification of seismic adequacy for USI A-46. The staff finds this approach acceptable provided that the anchorage evaluations previously performed meet the criteria and procedures approved by the staff in SSER Nc.2 (Section 11.4.4). The licensee also indicated that it plans to use existing seismic qualification test reports to demonstrate seismic adequacy for any equipment on its safe shutdown equipment lists (SSEls) which were previously qualified to IEEE 344-1975. The staff finds that this approach is acceptable for verifying equipment operability, but the licensee should also verify the seismic adequacy of the anchorage of this equipment in accordance with the criteria and procedures approved by the staff in SSER No. 2.

The licensee stated that it intends to use the Seismic Margin Methods defined in the Electric Power Research Institute's (EPRI) Report NP-6041-SL, dated August 1991, as one option for the resolution of equipment outliers. The methods defined in this report were intended to be used in conjunction with the seismic margin earthquake (SME), and not with the safe shutdown earthquake (SSE) used in USI A-46 reviews. The criteria and methods defined in the EPRI report are less conservative than those defined in GIP-2. Therefore, the methods defined in this report are, in general, not acceptable to the staff for resolving USI A-46 issues. Although the staff acknowledges that outlier resolution is beyond the scope of GIP-R, the staff generally endorses, with the clarifications provided in SSER No. 2, the types of outlier resolution described in Section 5 of GIP-2 (i.e., dynamic testing, engineering analysis, physical repair, anc replacement). As stated in Section 11.5 of SSER No. 2, "It is the responsibility of the utility to resolve outliers, using existing trocedures (e.g., plant-specific procedural controls and QA requirements) as it would resolve any other seismic concerns." The staff will consider the l

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application of some of the criteria provided in EPRI Report fiP-6041-SL, for the resolution of equipment outliers, on a case-by-case basis.

With regard to item 2, the licensee stated that it will submit the Safe Shutdown Equipment list Reports, the Relay Evaluation Reports, and the Seismic Evaluation Reports to the NRC providing the results of the USI A-46 program at the Haddam Neck Plant, within 180 days following the completion of Cycle #17 refueling outage (Spring 1993). The proposed implementation schedule for the Haddam Neck Plant is within the 3-year responsa period requested by the staff and is therefore acceptable.

With regard to item 3, the licensee stated that it "will, at our option, use any of the methods recommended by Section 4.2 of the GlP, for defining in-structure response spectra (demand) for comparison to the SQUG Bounding Spectrum and the Generic Earthquake Ruggedness Spectra," and that the licensee "will provide technical justification of the spectra generation methods where required by SSER-2 Section 11.4.2.4."

Since Haddam Neck is identified as a Category 2 (SEP) plant in Generic Letter 07-02, supplement No. 1, the staff finds that the licensee's response is adequate and acceptable, with one possible exception, which is discussed below, regarding the licensee's response to SSER No. 2,Section II.4.2.4.

Furthermore, if more than one set of in-structure response spectra appear in the licensing basis documents, the more conservative set of spectra must be used to qualify for the definition of " conservative design" in structure response spectra for the resolution of USI A-46 issues at Haddam Neck. If the licensee intends to use the option of developing or using " median centered" in-structure response spectra, the licensee is requested to inform the NRC staff the approximate date by which such information will become available.

With respect to SSER No. 2, Section 11.4.2.4, if the licensee intends to use the option of scaling IPEEE spectra for use in USI A-46, then the licensee's response is not acceptable since it did not provide the spectra generation methods as requested in SSER No. 2. Therefore, if the licensee intends to use this option, it should submit the information requested in SSER No. 2 as soon as possible for staff review.

The licensee indicated that, as part of the resolution of GL 87-02, it intends to change their licensing basis, via 10 CFR 50.59, to include the GIP methodologies as an option for demonstrating the seismic adequacy of new and replacement plant equipment. The staff recognizes that the licensee may revise its licensing basis in accordance with 10 CfR 50.59 to reflect the acceptability of the USl A-46 (GIP) methodology for verifying the seismic adequacy of electrical and mechanical equipment covered by the GIP. However, since the licensee intends to augment its licensing basis to include the GlP methodology as an option for verifying seismic adequacy, rather than revise its licensing basis such that the GIP-2 would be the sole methodology, the

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staff cautions that it is not acceptable to combine any part of GIP-2 with the current licensing basis methodologies such that it results in a less conservative approach than if GIP-2 or the current licensing basis methodologies were applied separately.

CONCLUS101{S The staff finds that the licensee's commitment to implement GIP-2, including the clarifications, interpretations and exceptions identified in SSER No. 2 to be an acceptable method for resolving USI A-46 at the Haddam Neck Plant.

The staff finds that it is acceptable for the licensee to use previously performed anchorage evaluations fc USI A-46, provided that the evaluations meet the criteria and procedures ap) roved in SSER No. 2 (Section 11.4.4). The staff also finds that it is accepta)le to use existing seismic qualification test reports to demonstrate operability for SSEL equipment which was qualified to IEEE 344-1975.

The methods defined in EPRI Report NP-6041-SL are, it, general, not acceptable to the staff for resolving equipment outliers. However, the staff will i.onsider the application of some of the criteria provided in EPRI Report NP-6041-SL, for the resolution of equipment outliers, on a case-by-case basis.

The proposed implementation schedule for the Haddam Neck Plant is within the 3-year response period requested by the staff and is therefore acceptable.

The staff has reviewed the licensee's response concerning in-structure response spectra, and has concluded that it is acceptable, with one possible exception where the licensee refers to SSER No. 2 Section 11.4.2.4. If the licensee intends to use scaled IPEEE spectra for US! A-46, it should submit for staff review as soon as possible, the information requested in SSER No. 2, Section !! 4.2.4. Furthermore, if more than one set of in-structure response spectra appear in the licensing basis documents, the more conservative set of spectra must be used to qualify for the definition of " conservative design" in-structure response spectra for the resolution of USI A-46 issues at Haddam Neck.

The staff recognizes that the licensee may revise its licensing basis in accordance with 10 CFR 50.59 to reflect the acceptability of the USI A-46 (GIP) methodology for verifying the seismic adequacy of electrical and +

mechanical equipment covered by the GIP. However, since the licensee intends to augment its licensing basis to include the GlP methodology as an option for verifying seismic adequacy, rather than revise its licensing basis sech that the GIP-2 would be the sole methodology, the staff cautions that it is not acceptable to combine any part of GIP-2 with the current licensing basis i methodologies such that it results in a less conservative approach than if l GIP-2 or the current licensing basis methodologies were applied separately.

Principal Contributors: P. Chen l D. Jeng l M. McBrearty Date: November 25, 1992 l

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