ML25093A060

10 CFR 2.206 - Diablo Canyon Units 1 and 2 Seismic - Proposed Directors Decision - L-2024-CRS-0000 OEDO-24-00083 - Attachment

ML25093A060
Person / Time
Site:	Diablo Canyon
Issue date:	04/10/2025
From:	Dennis Galvin NRC/NRR/DORL/LPL4
To:	Pacific Gas & Electric Co
Lee S, 301-415-3158
Shared Package
ML24264A091	List: ML24269A012 ML24302A148 ML24302A153 ML24302A154 ML24317A038 ML24317A039 ML25093A060
References
EPID L-2024-CRS-0000, OEDO-24-00083
Download: ML25093A060 (10)

Text

ATTACHMENT TO THE PROPOSED DIRECTORS DECISION DIABLO CANYON, NUCLEAR POWER PLANT, UNITS 1 AND 2 PACIFIC GAS AND ELECTRIC CO.

FIGURES 1 THROUGH 9 ADAMS ACCESSION NO. ML25093A060 Figure 1 Location of Diablo Canyon relative to major regional active fault systems that contribute the most to the hazard. (NUREG/KM-017 (ML21344A126))

Noto Pacific Eurasia Oshkosh Yangtze Okinawa Amur Figure 2 Location of the Noto Peninsula relative to the Amur and Oshkosh microplates.

(Wikipedia commons:

https://commons.wikimedia.org/wiki/File:Tectonic_plates_boundaries_detailed-en.svg)

Figure 3 USGS modeled slip distribution for 2024 Noto earthquake (https://earthquake.usgs.gov/earthquakes/eventpage/us6000m0xl/finite-fault)

Figure 4 Geologic map showing a triangular region bounding the California Coast Range with many NW striking faults that cut through Ceneozoic Era (66 Mya) sedimentary rocks that overlie older Mesozoic Era (252-66 Mya) basement rocks.*

• Langenheim, V. E., R. C. Jachens, R. W. Graymer, J. P. Colgan, C. M. Wentworth, and R. G. Stanley, Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault, Lithosphere, 5(1), 29-48, 2013.

Figure 5 Focal mechanisms of earthquakes near Diablo Canyon (NUREG/KM-017 (ML21344A126))

Figure 6 Locations of historical earthquakes in Central Coastal California from PG&Es SSC model SSHAC report. Modified to show location of Diablo Canyon site and 50 km radius.

(ML15071A046)

Diablo Canyon 50 km radius from Diablo Canyon Figure 7 from the NRC staffs confirmatory analysis of PG&Es hazard models shows the Hosgri, Shoreline, Los Osos, San Luis Bay, and the 18 virtual faults as dashed lines (ML16341C057).

Los Osos Fault San Luis Bay Fault Shoreline Fault Hosgri Fault Figure 8 Petitioner modified PG&E cross section with petitioners interpretation of subsurface fault geometry. Slide is from petitioner presentation (ML24198A105).

• Langenheim, V. E., R. C. Jachens, R. W. Graymer, J. P. Colgan, C. M. Wentworth, and R. G. Stanley, Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault, Lithosphere, 5(1), 29-48, 2013.

Figure 9. Profile taken from Langenheim et al.,* across the Irish Hills showing the magnetic and gravity data and model fits along with a geologic cross section that provides the modeled density and magnetic susceptibility values.