ML20198E508

Safety Evaluation Accepting Licensee 120-day Response to Suppl 1 to GL 87-02

ML20198E508
Person / Time
Site:	Brunswick
Issue date:	11/23/1992
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20198E505	List: ML20198E499 ML20198E508
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, NUDOCS 9212070257
Download: ML20198E508 (4)

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4 ENCLOSURE 1 u

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!'- n UNITED STATES i NUCLEAR REGULATORY COMMISSION o, WASHINoToN. D.C. 20h06 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE 120-DAY RESPONSE TO SUPPLEMENT NO, 1 TO GENERIC LETTER 87-02 FOR BRUNSWICK STEAM ELECTRIC PLANT. UNIT N05. 1 AND 2 ,

QOCKET NOS. 50-325 AND 50-324 4

l.0 " 'RODUCTlbN; By letter dated September 19, 1992, Carolina Power & Light Company, the licenste, submitted its response to Supplement No. I to Generic letter (GL) i 87-02, " Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46," dated May 22, 1992, for Brunswick Steam Electric Plant, Units 1 and 2 (BSEP 1 and BSEP 2). In this supplement, the staff requested that the licensees submit the following information within 120 days of the issue date of the supplement:

1. A statement whether the licensee commits to use both the Seismic Qualificattor, Utility Group (SQUG) commitments and the implementation l

guidance provided in the Generic implementation Procedure, Revision 2 (GIP-2) as supplennted by the staff's Supplemental Safety Evaluation Report No. 2 (SSER-2) for the resolution of USI A-46, in this case, any i deviation from GIP-2, as supplemented by the SSER-2, must be identified,

! Justified, and documented. if the licensee does not make such a commitment, the licensee must provide an alternative for responding to l GL 87-02.

. 2. A plant-specific schedule for the implementation of the GIP and submission l

of a report to the staff that summarizes the results of the USI A-46 review, if t5e licensee is committing to implement GIP-2. This schedule shall be sucn that each affected 31 ant will complete its implementation and submit the summary report wit 11n-3 years after the issuance of the SSER-2, unless otherwise justifieo.

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3. The detailed information as to what procedures-and criteria were used to l generate the in-structure response (IRS) spectra to be used for USI A-46 as requested in the SSER-2.- The licensee's IRS are considered acceptable for USI A-46 unless the staff indicates omrwise during a 60-day review period. ,

In additien, the staff requested in SSER-2 that the licensee inform the staff -

l in the-120-day response time if-it intends to chanse its licensing basis to

, reflect a commitment to the USI A-46 (GIP-2) methodnlogy for verifying the l seismic adequacy of mechanical and electrical equipmer,t, prior to receipt of l the staf f's plant-specific svaty evaluation resolving USI A-46.

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l 2-4 1 2.0 EVALUATION i i With regard to item 1, the licensee stated that it "... commits to the SQUG commitments set forth in the GIP-2 in their entirety, including the ,

clarifications, interpretations, and exceptions identified in SSER-2 as

clarified by the August 21, 1992, SQVG-letter res)onding to SSER-2." The >

i licensee also stated that it "... generally will se guided by the remaining l (non-commitment) sections of the GIP-2, i.e., GIP-2 implementation guidance, whict comprises suggested methods for implementing the applicable i commitments."

The licensee's response is unclear as to whether or not the licensee intends i to implement both the SQUG commitments and the implementation guidance, in i

accepting GIP-2 as a method for resolving USI A-46, it was the staff's i understanding that the SQUG menbers who chose to implement GIP-2 would i essentially uso the entire procedure, including the SQUG commitments, which t i contain the general programmatic objectives and goals, and the implementation j guidance, which contains the specific criteria and procedures to be used for j the resolution of USI A-46. This understanding was-the basis for the staff's position, which was stated in SSER-2, that if the licensee-commits to use i GIP-2 for the implement 1 tion of USI A-46, it must commit to both the SQUG commitments and the use of the entire implementation guidance provided in i GIP-2, unless otherwise justified to the staff. In order to allow soma l flexibility in implementing GIP-2, the staff acknowledged in the supplement to  !

i GL 87-02 that SQUG members who commit to GIP-2 (both the SQUG commitments and s the implementation guidance) may deviate from it provided that such deviations

! are identified, documented and justified. However, it was also indicated in-SSER-2 that if a licensee uses methods that deviate from the criteria and i procedures described in the SQUG commitments and in the implementation i guidance of GIP-2 without prior NRC approval, the staff may find the use of

j. such methods unacceptable with regard to satisfying the provisions of GL 87-02. ,

i in light of the above, the staff interprets the licensee's response to

Supplement No. I to GL 87-02 as a comn.itment to the entire GIP-2 including both the SQUG commitments and the implementation guidance, and therefore e

considers.it acceptable. - If the staff's interpretation is incorrect, then in

accordance with Supplement No. I to GL 87-02, the licensee should provide for

, staff review, as soon as practicable prior to implementation, its alternative-

! criteria and prccedures for responding to GL 87-02, t

i in addition, Enclosure 2 of the letter transmitting this Safety Evaluation

. (SE) provides the staff's response, dated October 2, 1992, to the August 21, 1992, SQUG 1etter. The staff does not concur with all of the SQUG's clarifications and positions stated in that letter, and thus, the licensee i- -should not use the August 21.-1992, letter as guidance in responding to '

- Supplement No. 1-to GL 87-02. The licensee should refer-to- Enclosure 2 for l- the staff's position _on the SQUG letter.

With regacd to item 2, the licensee stated that.it will submit a summary report to-the NRC summarizing the results of the USI-A-46 program at BSEP 1 by 120 days after the completion of BSEP 1 refueling outage 9 (scheduled for completion on December 28,1994), and, at BSEP 2 by 120 days after_.the-d

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completion of BSEP 2 refueling outage 11 (scheduled for completion on June 14, 1995). These submittal dates are within the 3-year response period requested by the staff and are therefore acceptable.

The licensee indicated that it may change its licensing basis methodology at BSEP 1 and BSEP 2, via 10 CFR 50.59, for verifying the seismic adequacy of new and replacement, as well as existing electrical and mechanical equipment prior to receipt of final plant-specific SEs resolving USI A-46. 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, if the licensee does not commit to implement both the SQUG commitments and the implementation guidance, and the licensee has not committed to any acceptable alternative criteria and procedures, then the staff does not believe that there is a basis for initiating a 10 CFR 50.59 review.

With regard to item 3, the NRC has reviewed the subject licensee response with a particular objective of assessing the acceptability of the response to item 11.4.2.3 of the SSER-2.

The plant safe shutdown earthquake (SSE) peak ground accelera.a ion (PGA) is i 0.169 The design response spectra (DRS) are based on the sm(othed 1940 NS El l Centro spectrum normalized to 0.089 PGA with the spectral shape and i amplifications similar to 84 percent NUREG-0098 spectra. An artificial I time-history was developed to envelope the DRS at the dam)ing values of I interest. This time-history was utilized in developing t1e IRS at various elevations. The spectral acceleration values are multiplied by two to arrive at the SSE IRS. 1he licensee states that the IRS should be cons Mered as

' conservative, design' spectra for verifying the equipment. All the principal parameters (e.g., the DRS, soil-structure com)11ance, modeling of structures,

, and three components of the earthquake) have 3een adequately considered in l arriving at the IRS. The damping values utilized are similar to those in l

Regulatory Guide 1.61. Overall, the amplifications and broadening of the IRS provided by the licensee at various floor levels appear to-be reasonable.

Based on the staff's review of the licensee response, and the staff positions delineated in the SSER-2, the staff concludes that the licensee response is adequate and acceptable, and that the IRS developed by the licensee should be considered as ' conservative design' IRS. This conclusion is based on the l

assumption that the statements made in the submittal, including the procedures i used in generation of the IRS, correctly reflect the FSAR and other licensing l bases. The staff may audit the process by which the IRS were generated.

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3.0 CONCLUSION

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1 I The NRC staff interprets the licensee's response to Supplement-No. I to GL i 87-02 as a commitment to the entire GIP-2 including both the-SQUG commitments i and the implementation guidance, and therefore considers it acceptable. If the licensee does not commit to-implement the entire GIP-2, then in accordance with Supplement No.-1 to GL 87-02, the licensee should provide for staff review, as soon as practicable prior to. implementation,t its alternative i criteria and trocedures for responding to GL 87-02. Additionally, .

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i 4-the implementation schedules proposed by the licensee are within the 3-year response period requested by the staff in Supplement No. I to GL 87-02 and are

, therefore acceptable.

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 (GlP) methodology for verifying the seismic adequacy of electrical and mechanical equipment covered by the GIP. However, if the licensee does not commit to implement both the SQUG commitments and the implementation guidance, and the licensee has not committed to any acceptable alternative criteria and >

procedures, then the staff does not believe that there is a basis for i initiating a 10 CFR 50.59 review. ,

Based on the staff review of the licensee's response and the staff positions delineated in the SSER-2, we conclude that the procedures used to generate the IRS are adequate and acceptable, and that the IRS-developed by the licensee should be considered as ' conservative design' IRS. This conclusion is based ,

on the assumption that the statements made in the submittal, including the procedures used in generation of the IRS, correctly reflect the' FSAR and other licensing basis.

Principal Contributors: P. Y. Chen M. McBrearty H. Ashar J. Stewart 1

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A ENCLOSURE 2

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NUCLEt R REGULATORY COMMISSION wAsmnoToN. o, c. acons OCT 01 g Mr. Neil Smith, Chairman Seismic Qualification Utility Group c/o EPRI 1019 19th Street, N.W.

Washington, DC 20036

SUBJECT:

NRC RESPONSE TO SEISMIC QUALIFICATION UTILITY GROUP (SQUG)

Re: Letter, N. Smith, EPRI, To J. Partlow, NRR, dated August 21, 1992, concerning USI A-46 Issues.

Dear Mr. Smith:

This is to acknowledge the receipt of the SQUG response to Supplement No. I to Generic Letter (GL) 87-02, and Supplemental Safety Evaluation (SSER) No. 2, on the SQUG Generic Implementation Procedure for Seismic Verification of Nuclear i Plant Equipment, Revision 2, as corrected February 14, 1992 (GIP-2). The NRC staff believes that successful implementation of the entire GIP-2, supple-mented by the staff's SSER No. 2, by each SQUG licensee will result in cost-effective plant safety enhancement for their USI A-46 plants.

The staff also believes that the positions delineated in Supplement No I to GL 87-02 and SSER No. 2 are clear and correct, and should not be misinterpret-ed. The staff's comments on SQUG's August 21, 1992, letter and attachment are provided in the enclosure to this letter. If you need further clarification concerning our response, please contact Mr. James Norberg at 504-3288.

Sincerely, e

W dit James G. Partlow Associate Director for Projects Office of Nuclear Reactor Regulation

Enclosure:

As stated -

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ENCLOSURE

1. hpr;L i g entt on ' M SOUG Letter of Auoust 21. 1992:

i. 16 nemt te t> , issue of seismic qualification, the staff r W R. net 'Lt.e position stated in the SSER No. 2, in that the Q ! Nr.ocology is not considered to be a seismic qualification R .c A. rather, it is an acceptable evaluation method, for USI A-O t! <.ts only, to verify the seismic adequacy of the safe-u d oown equipment and to ensure that the pertinent equipment seismic requirements of Gerieral Design Criterion 2 and the purpose of the NRC regulations relevant to equipment seismic adequacy including 10 CFR Part 100 are satisfied.

2. The second paragraph on page 2 of your letter addressed the issue of timing of staff response to additional information requested from a licenses. Although you are correct in your statement regarding the sixty-day period for response to initial submittal of in-structure response spectra (ISRS) information, we do not agree that the same concept applies to a licensee's submittal of additional information received following a rejection or a question from the staff. To eliminate any potential misunder-standing in this regard, the staff has determined that it will respond to any submittal of additional information received from a licensee within 60 days. However, in this response, the staff will either state its approval (or rejection) of the information provided, or indicate the time duration needed for the review of such information, prior to transmitting a follow-up response of 4

acceptance (or rejection) to the licensee. This time duration will vary depending on the complexity of the submittal.

3. Regarding the EBAC and ANCHOR computer. codes, the staff's evaluations and concerns stated in the SSER No. 2 are correct and valid. The ANCHOR code does not consider the effects of base plate tiexibility on the anchorage capacity.

4. With respect to transfer of knowledge regarding major problems identified, and lessons learned, in the USI A-46 plant walkdowns and third-party reviews, we request that you include the NRC in the distribution of written communications to all member utilities in this regard, and inform the NRC staff of any planned workshops e A-46 implementation for possible staff participation.

11. NRC's Cements on the Procedure for Reviewina the GIP

1. The staff supports SQUG's establishment of a Peer Review Panel composed of seismic experts since it should serve to enhance the review process of substantive changes to the technical requirements in the GIP, prior to its submittal to NRC for approval. However, since the NRC no longer intends to help finance a Peer Review Panel, the staff does not believe it

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2 is appropriate to participate in the selection of the Peer Review -

members, who will be financed by SQUG/EPRI. We would like to emphasize that staff's review of a proposed GIP change will receive thorough independent NRC evaluation and will be assessed on its merits.

2. With respect to the NRC review and approval of the changes to the GlP (Item 5, page 3 of the procedure), the staff's position on the issue of its response timing is identical to that delineated in the response to a licensee submittal of additional information (refer to item 2 of NRC's Comments on the SQUG letter in this enclosure). This comment also applies to the section " LICENSING CONSIDERATIONS" on page 5 of the Attachment to the SQUG 1etter.

3. With respect to item 4, " Additional Restrictions," the text should be expanded to reflect that new information which indicates that existing GIP criteria and guidelines may be unconservative should be evaluated for potential 10 CFR Part 21 implications.

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