ML12300A105
| ML12300A105 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/25/2012 |
| From: | Allen B Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-12-1 08 | |
| Download: ML12300A105 (5) | |
Text
_ _ Pacific Gas and
~&~ Electric Company Diablo Canyon Powe r Plan t PO. Box 56 Av il a Beach, CA 93 424 October 25, 2012 800.545 .6000 PG&E Letter DCL-12-1 08 U.S. Nuclear Regulatory Commission 10 CFR 50.90 ATTN: Document Control Desk Washington, D.C. 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Withdrawal of License Amendment Request 11-05, "Evaluation Process for New Seismic Information and Clarifying the Diablo Canyon Power Plant Safe Shutdown Earthquake"
References:
(1) PG&E Letter DCL-11-097, "License Amendment Request 11-05, 'Evaluation Process for New Seismic Information and Clarifying the Diablo Canyon Power Plant Safe Shutdown Earthquake,'" dated October 20,2011 (2) NRC Letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident," dated March 12, 2012 (3) NRC Letter, "Diablo Canyon Power Plant, Units Nos. 1 and 2 - NRC Review of Shoreline Fault (TAC Nos. ME5306 and ME5307)," dated October 12, 2012 (4) NRC Research Information Letter 12-01, "Confirmatory Analysis of Seismic Hazard at the Diablo Canyon Power Plant from the Shoreline Fault Zone,"
dated September 2012 (5) NRC Letter, "Summary of June 20, 2011, Pre-licensing Meeting with Pacific Gas and Electric Company on Proposed License Amendment for a New Seismic and Design Evaluation Process (TAC Nos. ME5033 and ME 5034),"
dated July 29, 2011 (6) PG&E Letter DCL-11-124, "Standard Review Plan Comparison Tables for License Amendment Request 11-05, 'Evaluation Process for New Seismic Information and Clarifying the Diablo Canyon Power Plant Safe Shutdown Earthquake,'" dated December 6, 2011 (7) PG&E Letter DCL-91-091, "Benefits and Insights of the Long Term Seismic Program," dated April 17, 1991 A member of the STARS (Strateg ic Teaming and Resou rce Sha ri ng) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre
- South Te xas Project
- Wolf Creek
I~
Document Control Desk PG&E Letter DCL-12-1 08 October 25,2012 I & Page 2 .
Pursuant to 10 CFR 2.107, Pacific Gas and Electric Company (PG&E) hereby withdraws License Amendment Request (LAR) 11-05 "License Amendment Request 11-05, 'Evaluation Process for New Seismic Information and Clarifying the Diablo Canyon Power Plant Safe Shutdown Earthquake,'" dated October 20,2011 (Reference 1).
Reference 1 requested the NRC's review and approval to revise the current licensing basis, as described in the Updated Final Safety Analysis Report (UFSAR) and Technical Specifications, to provide requirements for the actions, evaluations, and reports necessary when PG&E identifies new seismic information relevant to the design and operation of Diablo Canyon Power Plant (DCPP).
In Reference 1, PG&E proposed to: (1) clearly define an evaluation process for newly identified seismic information and incorporate ongoing commitments associated with the Long Term Seismic Program (LTSP) into the UFSAR; (2) clarify, consistent with the NRC Supplemental Safety Evaluation Report 7, that the 1977 Hosgri earthquake (HE) is the equivalent of DCPP's safe shutdown earthquake, as defined in 10 CFR 100, Appendix A; and (3) use the square-root-of-the-sum-of-squares (SRSS) method for the evaluation of load combinations of seismic with loss-of-coolant accident (LOCA).
Due to the issuance of the NRC Letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident," dated March 12, 2012 (Reference 2), and the issuance of NRC Letter, "Diablo Canyon Power Plant, Units Nos. 1 and 2 - NRC Review of Shoreline Fault," dated October 12,2012 (Reference 3), PG&E no longer has a need for approval of Reference 1.
Reference 2 defines an evaluation process for newly identified seismic information for all nuclear power plants in the United States of America. Therefore, PG&E no longer requests the NRC's review of a plant specific evaluation process for new seismic information.
References 3 and 4 document the NRC staff's assessment that deterministic seismic-loading levels predicted for all the Shoreline fault earthquake scenarios developed and analyzed by the NRC are at, or below, those levels for the HE ground motion and the LTSP ground motion. The HE ground motion and the LTSP ground motion are those for which DCPP was evaluated previously and demonstrated to have reasonable assurance of safety.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre
- South Texas Project
- Wolf Creek
m Document Control Desk October 25, 2012
- & Page 3 PG&E Letter DCL-12-1 08 Based on the NRC concluding that the Shoreline scenario should be considered as a lesser included case under the HE evaluation, PG&E will update UFSAR, as necessary, to include the Shoreline scenario in accordance with the requirements of 10 CFR 50.71 (e).
PG&E has continued to review DCPP's current licensing basis through the 10 CFR 50.59 process to determine if PG&E can incorporate the SRSS methodology for the evaluation of load combinations of seismic with LOCA without prior NRC approval. Based on the results of the continued review, PG&E may choose to submit a new LAR requesting the NRC's review and approval for the use of the SRSS method for the evaluation of load combinations of seismic with LOCA in the future.
Prior to submitting Reference 1, the NRC Staff conducted the last of four pre-licensing public meetings (Reference 5) with PG&E on June 20,2011. The Staff requested that:
.. .the amendment needed to describe where the methodologies and acceptance limits used in the evaluation of structures and components for the HE are deviating from the applicable provisions in the Standard Review Plan (SRP) .
... a table providing the deviations from the SRP for the HE should be provided with this LAR.
PG&E prepared the comparison tables provided as Enclosure 1 to PG&E Letter DCL-11-124 (Reference 6). As PG&E no longer requests the NRC's review of Reference 1, PG&E also withdraws Reference 6.
With the issuance of Reference 2, PG&E reviewed its existing commitments to the evaluation of new seismic information and identified the following commitment in DCPP Supplement Safety Evaluation Report 34:
PG&E made the following commitments at the public meeting on March 15, 1991, and in a letter from PG&E to the NRC [Reference 7]: (1) to continue to maintain a strong geosciences and engineering staff to keep abreast of new geological, seismic, and seismic engineering information and evaluate it with respect to its significance to Diablo Canyon ...
PG&E is adding to this existing commitment to state that PG&E will evaluate new seismic information consistent with the evaluation process defined in Reference 2.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre
- South Texas Project
- Wolf Creek
m I
Document Control Desk October 25, 2012
& Page 4 PG&E Letter DCL-12-1 08 PG&E has the following near term activities scheduled in support of its ongoing efforts to evaluate new seismic information:
Senior Seismic Hazard Analysis Committee Level III studies - Seismic Source Characterization study and Ground Motion Characterization study are being conducted to provide a Probabilistic Seismic Hazard Analysis update that is scheduled to be completed with results submitted to the NRC by March 12, 2015, as required by Reference 2.
In response to Reference 2, PG&E will use the double design earthquake for comparison with the reevaluated seismic hazard ground motion response spectrum.
If during PG&E's ongoing collection of seismic data, new faults are discovered or information is uncovered that would suggest the Shoreline fault is more capable than currently believed, PG&E will provide the NRC with an interim evaluation that describes actions taken or planned to address the higher seismic hazard relative to the design basis, as appropriate, prior to completion of the evaluations requested in the NRC Staff's March 12, 2012, request for information (Reference 2).
PG&E is making new regulatory commitments (as defined by NEI 99-04) in this letter. The commitments ,are contained in the Enclosure to this letter.
If you have any questions or require additional information, please contact Mr. Nozar Jahangir at (805) 545-6512.
Sincerely, v3~ 5 . A-U--
Barry s. Allen Site Vice President Enclosure prs/6984/50519182 cc: Elmo E. Collins, NRC Region IV Laura H. Micewski, NRC, Acting Senior Resident Inspector Gonzalo L. Perez, Branch Chief, California Department of Public Health Joseph M. Sebrosky, NRC Project Manager, Office of NRR Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onof re
- South Texas Project
- Wolf Creek
PG&E Letter DCL-12-1 08 Enclosure List of Regulatory Commitments Commitment 1:
Based on the NRC concluding that the Shoreline scenario should be considered as a lesser included case under the Hosgri earthquake evaluation, PG&E will update the Updated Final Safety Analysis Report, as necessary, to include the Shoreline scenario in accordance with the requirements of 10 CFR 50.71 (e).
Commitment 2:
PG&E is adding to the existing Long Term Seismic Program commitment (Reference 7) to state that PG&E will evaluate new seismic information consistent with the evaluation process defined in Reference 2.
Commitment 3:
In response to Reference 2, PG&E will use the double design earthquake for comparison with the reevaluated seismic hazard ground motion response spectrum.
Commitment 4:
If during PG&E's ongoing collection of seismic data, new faults are discovered or information is uncovered that would suggest the Shoreline fault is more capable than currently believed, PG&E will provide the NRC with an interim evaluation that describes actions taken or planned to address the higher seismic hazard relative to the design basis, as appropriate, prior to completion of the evaluations requested in the NRC staff's March 12, 2012, request for information (Reference 2).
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