[Federal Register Volume 89, Number 170 (Tuesday, September 3, 2024)]
[Notices]
[Pages 71432-71433]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19630]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-275 and 50-323; NRC-2024-0148]


Pacific Gas & Electric Company; Diablo Canyon Power Plant, Unit 
Nos. 1 and 2; Petition

AGENCY: Nuclear Regulatory Commission.

ACTION: 10 CFR 2.206 request; receipt.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is giving notice 
that by petition dated March 4, 2024, as supplemented on June 7, 2024, 
San Luis Obispo Mothers for Peace, Friends of the Earth, and 
Environmental Working Group (the petitioners) requested that the NRC 
exercise its supervisory authority to order the immediate closure of 
Diablo Canyon Nuclear Power Plant, Unit Nos. 1 and 2 (Diablo Canyon) 
due to ``the unacceptable risk of a seismically induced severe 
accident.'' The Commission referred the request to the enforcement 
petition process under NRC regulations. The petitioners' request is 
included in the SUPPLEMENTARY INFORMATION section of this document.

DATES: September 3, 2024.

ADDRESSES: Please refer to Docket ID NRC-2024-0148 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2024-0148. Address 
questions about Docket IDs in Regulations.gov to Stacy Schumann; 
telephone: 301-415-0624; email: [email protected]. For technical 
questions, contact the individual listed in the For Further Information 
Contact section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, 
or by email to [email protected]. For the convenience of the reader, 
instructions about obtaining materials referenced in this document are 
provided in the ``Availability of Documents'' section.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Perry Buckberg, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001; telephone: 301-415-1383; email: [email protected].

SUPPLEMENTARY INFORMATION: On March 4, 2024, the petitioners filed a 
petition requesting that the NRC exercise its supervisory authority to 
order the immediate closure of Diablo Canyon due to ``the unacceptable 
risk of a seismically induced severe accident.'' An order was issued on 
March 12, 2024, referring the request to the enforcement petition 
process under section 2.206 of title 10 of the Code of Federal 
Regulations (10 CFR), ``Requests for action under this subpart.''
    The specific concerns expressed in the March 4, 2024, petition, as 
supplemented on June 7, 2024, now include:
    1. Thrust faulting is neglected by Pacific Gas & Electric Company's 
(PG&E's) 2012 Seismic Source Characterization (SSC) model, because the 
model assumes that a majority of large earthquakes affecting Diablo 
Canyon are strike-slip and disregards the significant contribution of 
thrust faulting earthquake sources under the Diablo Canyon site and the 
adjacent Irish Hills. In addition, PG&E did not use a hanging-wall term 
for the modeling of potential ground motions from the Los Osos and San 
Luis Bay thrust faults.
    2. The January 2024 magnitude 7.5 (moment magnitude) earthquake 
centered in the Noto Peninsula (Japan), with an average slip of 2 
meters on the fault, is analogous to future potential thrust mechanism 
earthquakes beneath Diablo Canyon. Based on the slip rate of the Irish 
Hills adjacent to Diablo Canyon and the slip of the Noto earthquake, 
large thrust fault earthquakes will occur, on average, every 715 years 
near the Diablo Canyon site.
    3. PG&E's 2012 SSC model does not account for an inferred offshore 
thrust fault that has a slip rate of 2.8 millimeters per year (mm/yr) 
and the potential for producing a magnitude 7.5 earthquake.
    4. Seismic core damage frequency estimated by PG&E in 2018 to be 3 
x 10-5, should be 1.4 x 10-3 per year (about once 
every 715 years) based on this higher recurrence rate for thrust 
earthquakes.
    The NRC staff assembled a Petition Review Board (PRB) in accordance 
with NRC Management Directive (MD) 8.11, ``Review Process for 10 CFR 
2.206 Petitions,'' and its associated Directive Handbook 8.11, Section 
III. In an email dated May 15, 2024, the petition manager informed the 
petitioners that the PRB's initial assessment was to not accept the 
petition for review. The PRB's position was that the petition did not 
meet the criteria in MD 8.11 for accepting petitions under 10 CFR 2.206 
because ``the issues raised have previously been the subject of a 
facility specific or generic NRC staff review . . .'' and the petition 
does not provide significant new information that the staff did not 
consider in a prior review.
    On May 15, 2024, along with the initial assessment, the petition 
manager offered the petitioners an opportunity to address the PRB in a 
public meeting, which was accepted by the petitioners.

[[Page 71433]]

    The June 7, 2024, supplement to the petition responded to the PRB's 
initial assessment.
    The NRC then held the public meeting on July 17, 2024. During the 
meeting, the petitioner's presentation discussed and expounded on 
information from the supplement dated June 7, 2024, and included 
graphics to represent their position. The transcript of that meeting is 
considered a supplement to the petition.
    Following the public meeting, the PRB met to consider what had been 
presented during the meeting. The PRB determined that the concerns as 
previously described in this notice, which were raised in the original 
petition and supplements, meet the criteria in MD 8.11, Sections 
III.C.1(a) and (b) and will be accepted into the 10 CFR 2.206 process 
for further review by the PRB in accordance with MD 8.11. The PRB also 
determined that there is no imminent safety concern that warrants 
immediate shutdown of Diablo Canyon. On August 22, 2024, the petition 
manager informed the petitioners of this outcome.

Availability of Documents

    The documents identified in the following table are available to 
interested persons through ADAMS.

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             Document description                  ADAMS Accession No.
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Petition submitted by San Luis Obispo Mothers   ML24067A066
 for Peace, Friends of the Earth, and
 Environmental Working Group, dated March 4,
 2024.
NRC SECY Order referring the petition to the    ML24072A529
 10 CFR 2.206 process, dated March 12, 2024.
Petition Supplement, dated June 7, 2024.......  ML24162A079
NRC Management Directive 8.11, ``Review         ML18296A043
 Process for 10 CFR 2.206 Petitions,'' dated
 March 1, 2019.
Email from the NRC to the Petitioners re        ML24136A162
 Diablo Canyon Seismic Core Damage 2.206
 petition--Initial Assessment, dated May 15,
 2024.
July 17, 2024, Public Meeting Petitioner        ML24198A105
 Presentation to the PRB.
July 17, 2024, Public Meeting Official          ML24218A164
 Transcript of Proceedings.
Email from the NRC the Petitioners re Diablo    ML24235A203
 Canyon Seismic Core Damage 2.206 petition--
 Accepted, dated August 22, 2024.
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    Dated: August 27, 2024.

    For the Nuclear Regulatory Commission.
Michael X. Franovich,
Acting Deputy Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2024-19630 Filed 8-30-24; 8:45 am]
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