ML20128A717

Safety Evaluation Accepting Licensee 920921 120-day Response to Suppl 1 to GL 87-02 as Commitment to Entire GIP-2, Including Both SQUG Commitments & Implementation Guidance. In-structure Response Spectra Addressed in Separate SE

ML20128A717
Person / Time
Site:	Prairie Island
Issue date:	11/30/1992
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20128A652	List: ML20128A650 ML20128A717 ML20128A730
References
GL-87-02, GL-87-2, NUDOCS 9212030432
Download: ML20128A717 (3)

Text

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.f 6 ? g NUCLEAR REGULATORY COMMISSION

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%.'..** / SAFETY E' VALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION' :l EVALUATION OF THE NORTHERN STATES POWER COMPMY'.S PRA11IE ISLAND NUCLEAR GENERATING PLANT. UN11S 1 AND 2 120-DAY RESPONSE TO SUPPLEMENT NO.1 TO GENJBJ1 LETTER 87-02.-

D_QCKET NOS. 50-282 AND 50-306 BACKGROUM I

By letter dated September 21, 1992, the Northern States Power Company, the-

• licensee, submitted its response to Supplement.No. I to Generic Letter (GL) 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 the Prairie Island -Nuclear Generating Plant, Units _1 and 2.

In Supplement No. I to GL 87-02, the staff requested that the licensee 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 (SQUG) commitments and the implementation-guidance provided .

in the Generic Implementation Procedure, Revision 2 (GIP-2) as supplemented-by the staff's Supplemental Safety Evaluation Report No. 2- (SSER No. 2) for the resolution of USI A-46. In this case, any deviation from GIP-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 l of a report to the staff that summarizes the results of the USI A-46 _

w 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 criteria were used to generate the in-structure response spectra to be used for USI 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 L

during'a 60-day review period.

In addition, the staff requested in SSER No. 2'that the. licensee inform the staff, in' the 120-day response, if it: intends to change'its licensing basis to reflect a commitment to the USI A-46 (GIP-2) methodology for verifying the seismic adequacy of mechanical and electrical equipment, prior to receipt of ~

9212030432 921130

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the staff's plant-specific safety evaluation resolving USI A-46. This report provides the Mechanical Engineering Branch's (EMEB) evaluation of the licensee's response for these areas which fall under the review responsibility of EMEB.

EVALUATION With regard to Item 1, the licensee stated that, "Specifically, Northern States Power hereby commits to the SQUG commitments set forth in the GIP in their entirety, including the clarifications, interpretations, and exceptions identified in SSER-2 as clarified by the August 21, 1992, SQUG letter responding to SSER-2." The licensee also stated that it "... generally will be guided by the remaining (non-commitment) sections of the GIP, i.e., GIP implementation guidance, which comprises suggested-methods for implementing the applicable commitments."

The licensee's response is unclear as to whether or not the licensee intends to implement both the SQUG commitments and the implementation guidance. In accepting GIP-2 as a method for resolving USI A-46, it was the staff's under-standing that the SQUG members who chose to implement GIP-2 would essentially use the entire procedure, including the SQUG commitments, which contain the general programmatic objectives and goals, and the implementation guidance, whici: contains the specific criteria and procedures to be used for the resolu-tion of USI A-46. This understanding was the basis for the staff's position, which was stated in SSER No. 2, that if the licensee commits to use GIP-2 for the implementation of USI A-46, it must commit to both the SQUG commitments and the use of the entire implementation guidance provided in GIP-2, unless otherwise justified to the staff. In order to allow some flexibility in implementing GIP-2, the staff acknowledged in the supplement to GL 87-02 that SQUG members who commit to GIP-2 (both the SQUG commitments and the implementation guidance) may deviate from it provided that such deviations are identified, documented and justified. However, it was also_ indicated in SSER No. 2 that if a licensee uses methods that deviate from the criteria and pro-cedures described in the SQUG commitments and in the implementation guidance of GIP-2 without prior NRC approval, the staff may find the use of.such methods unacceptable with regard to satisfying the provisions of GL 87-02.

In light of the above, the staff interprets the licensee's response to Supplement No. I to GL 87-02 as a commitment to the entire GIP-2 including both the SQUG commitments and the implementation guidance, and therefore cor.siders 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 procedures for responding to GL 87-02.

In addition, Enclosure 3 provides the staff's response, dated October 2, 1992, to the August 21, 1992, SQUG letter. The staff does not concur with all of the SQUG's clarifications and positions stated in that letter, and thus, the

, licensee should not use the August 21, 1992, letter as guidance in respcading to Supplement No.- I to GL 87-02. The licensee should refer to Enclosure 3 for -

the staff's position on the SQUG letter.

9 l -

3 With regard 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 the Prairie Island Nuclear Generating Plant by November 20, 1995. This submittal date is within the 3-year response period requested by the staff and is therefore acceptable.

With regard to Item 3, the Civil Engineering and Geosciences Branch (ECGB) has reviewed the licensee's in-structure response spectra to be used for USI A-46 evaluations, and has documented its findings in a seperate safety evaluation included as Enclosure 2.

Additionally, the staff disagrees with the licensee's comments regarding the timing of staff responses to additional information requested from the licensee. The licensee essentially reiterated the SQVG position stated in the August 21, 1992, letter from SQUG to the NRC. The licensee should refer to item I.2 in Enclosure 3 for the staff's position on this isste.

It is noted that the licensee did not indicate in its submittal that ii intends to change its licensing basis to reflect a commitment to the USI A-46 methodology prior to receipt of the staff's plant-specific SER.

GONCLUSIONS The staff interprets the licensee's response to Supplement No. I to GL 87-02 as a commitment to the entire GIP-2 including both the SQUG commitments and the implementation guidance, and therefore considers it acceptable. If the licensee does rot commit to implement the entire GIP-2, then in accordance with St., plement No. I to GL 87-02, the licensee should provide for staff review, as soon as practicable prior to implementation, its alternative criteria and procedures for responding to GL 87-02. Additionally, the 1teensee should not merely follow the August 21, 1992, SQUG letter for implementing GIP-2, but should refer to Enclosure 3 for the staff's response to the SQUG letter.

The implementation schedule proposed by the licensee is within the 3-year response period requested by the staff in Supplement No. I to GL 87-02 and is therefore acceptable.

The acceptability of the licensee's in-structure response spectra has been addressed separately by ECGB in Enclosure 2.

The staff disagrees with the licensee's comments regarding the timing of staff responses to additional information requested from the licensee. The licensee should refer t , Item 1.2 in Enclosure 3 for the staff's position on this issue.