ML15159B297

Near-Term Task Force Recommendation 2.1 (R2.1) Seismic Hazard Evaluation - Arizona Public Service, Palo Verde Nuclear Generating Station Public Meeting - June 9, 2015

ML15159B297
Person / Time
Site:	Palo Verde
Issue date:	06/09/2015
From:	Japan Lessons-Learned Division
To:
Vega F, NRR/JLD, 415-1617
References
Download: ML15159B297 (16)

Text

Near-term Task Force Recommendation 2.1 (R2.1) Seismic Hazard Evaluation Arizona Public Service Palo Verde Nuclear Generating Station Public Meeting June 9, 2015

References and Logistics NRC Presentation Slides

- ML15159B297 NRC Technical Focus Area Questions

-ML15147A068 Licensee Presentation Slides

- ML15156B331 Licensee Hazard Report and Supplement - ML15076A073; ML15105A076 Screening and prioritization results

- ML15113B344 Meeting Feedback Form (request from fgv1@nrc.gov or njd2@nrc.gov) Meeting Summary to be issued within 30-day 2 Meeting Purposes Gather additional information based on early identification of areas where additional technical information will support the staff's review Gain a better understanding of how the licensee conducted their evaluation 3

Outline Overview of Recommendation 2.1

- Response to NRC 50.54(f) letter Screening and Prioritization results NRC approach to seismic hazard characterization reviews for Western US (WUS) sites Review schedules and timeline

4 Seismic R2.1 Process Ensures Clarity, Consistency, and Risk

-Informed Regulatory Decisions 5 NRC makes Regulatory Decisions as Needed

• Safety Enhancements

• Backfit Analysis

• Modify Plant License PHASE 2 DECISION-MAKING Interact with Industry on Hazard and Risk Evaluation Guidance CEUS Licensees submit Site Response (9/2013 & 3/2014) Licensees submit Hazard Reevaluations and Interim Evaluations, as needed (CEUS:3/2014,WUS:3/2015)

Screen and prioritize plants for Risk Evaluation.

Review Interim Evaluations, as needed (CEUS:5/2014; WUS:5/2015)

Screened-in plants complete Expedited Interim Evaluation (CEUS:12/31/2014;WUS:1/2016) and Risk Evaluation (Group 1:

6/2017) NRC reviews Risk Evaluation PHASE 1 STAGE 1 STAGE 2 INFORMATION GATHERING

Seismic Screening and Prioritization results NRC Letter issued for WUS sites on May 13, 2015 (ML15113B344)

Palo Verde has been conditionally screened-in for seismic risk evaluation and limited scope evaluations

-Review Group 3 plant No immediate safety issues identified Information supports safety assurance allowing additional time to complete the seismic risk evaluation 6

NRC Review of SSHAC Studies for WUS Sites Did SSHAC process follow NRC guidance?

How effective was the peer review panel?

Have all applicable data been considered?

Were data uncertainties identified and considered?

Was an appropriate range of applicable models considered?

How were models selected and weighted in the analysis? How were models assembled into the PSHA? 7 NRC Review of Source Models for WUS Sites How were seismic sources identified?

-Geologic mapping

-Geophysical observations

-Earthquake catalog How were seismic sources characterized?

-Geometry (location, length, dip)

-Range of magnitudes

-Faulting style (normal, reverse, strike

-slip) -Slip rate and recurrence models

-Complex rupture scenarios 8 NRC Review of Ground Motion Models and Site Response for WUS Sites Do final ground motion models capture a reasonable range of alternative models?

How were sources of uncertainty captured in model development?

How were ground motion models adjusted for local site geology?

Does site response analysis cover a reasonable range of alternative soil/rock properties?

How was uncertainty in site response analysis incorporated into final probabilistic hazard

curves? 9 WUS Hazard Staff Review Timeline May: Screening and prioritization letter June: Public meetings Late summer/early fall: Staff questions Fall: NRC final screening letter including ESEP response December: GMRS suitability Letter Summer/Fall 2016: Document Hazard review December 2020: Risk Evaluation submittal (Grp 3) 10 Break for NRC Staff Alignment 5 - 10 minute planned break for NRC staff alignment to support meeting wrap

-up 11 Opportunity for Public Questions or Comments Additional Questions?

Please ask us at:

JLD_Public.Resource@nrc.gov 12 List of Acronyms CEUS - Central and Eastern United States ESEP - Expedited Seismic Evaluation Process (for Interim Evaluation)

GMRS - Ground Motion Response Spectrum NRC - U.S. Nuclear Regulatory Commission NPP - Nuclear Power Plant NTTF - Near-Term Task Force PSHA - Probabilistic Seismic Hazard Analysis SFP - Spent Fuel Pool SMA - Seismic Margins Analysis SPID - Screening, Prioritization, and Implementation Details SPID SPRA - Seismic Probabilistic Risk Assessment SSC - Structures, Systems and Components SSHAC - Senior Seismic Hazard Analysis Committee SSE - Safe Shutdown Earthquake SPID - Screening, Prioritization, and Implementation Details WUS - Western United States

13 Backup Slides

14 Guidance Documents Two main guidance documents proposed by industry and endorsed by the NRC Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012

-Endorsed by NRC on February 15, 2013

-EPRI-1025287 (ML12333A170)

Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach)

-Submitted by EPRI on April 9, 2013

-Endorsed by NRC on May 7, 2013

-EPRI-3002000704 (ML13102A142) 15 2012 2013 2014 2015 2016 2017 2018 2019 2020 Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority CEUS CEUS Group 1 Only plants with new seismic hazard exceeding design basis All plants Hazard Analyses WUS Group 3 (as needed)

WUS Group 2 Risk Evaluations plant mods plant mods E E E E E Staff Assessment or response Staff acknowledgement to use GMRS for risk

evaluation Expedited Interim Evaluations Schedule for Seismic Hazard and Risk Evaluations 16