DCL-22-032, 2021 Annual Nonradiological Environmental Operating Report

2021 Annual Nonradiological Environmental Operating Report

ML22117A176
Person / Time
Site:	Diablo Canyon
Issue date:	04/27/2022
From:	Petersen D Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-22-032
Download: ML22117A176 (7)

Text

Pacific Gas and Electric Company*

Dennis Petersen Diablo Canyon Power Plant Station Director Mail code 10415/502 P.O. Box 56 Avila Beach, CA 93424 805.545.4022 Internal: 691.4022 PG&E Letter DCL-22-032 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Power Plant, Units 1 and 2 2021 Annual Nonradiological Environmental Operating Report

Dear Commissioners and Staff,

Enclosed is the 202 1 Annual Nonradiological Environmental Operating Report for Diablo Canyon Power Plant, Units 1 and 2. This report is being submitted in accordance with Subsection 5.4 .1 of the Environmental Protection Plan , Appendix B of the Facility Operating License Nos. DPR-80 and DPR-82.

Pacific Gas and Electric Company makes no new or revised regulatory comm itments (as defined by NEI 99-04) in this letter.

If you have questions concerning this report, please contact Mr. David Cortina , Chemistry and Environmental Operations Manager, at (805) 545-3517.

Sincerely ,

~If~

Dennis Petersen Date armb/50941710 Enclosure cc : Diablo Distribution cc/enc: Natasha A. Greene, PhD, NRC Acting Senior Resident Inspector Samson S. Lee, NRR Project Manager Scott A. Morris, NRC Reg ion IV Administrator Matthew T. Keeling , Executive Officer, Central Coast Regional Water Quality Control Board A member of the STARS Allia nce Callaway

• Di ablo Canyo n

• Palo Verd e

• Wolf Creek

Enclosure PG&E Letter DCL-22-032 2021 ANNUAL NONRADIOLOGICAL ENVIRONMENTAL OPERATING REPORT DIABLO CANYON POWER PLANT, UNITS 1 AND 2 Pacific Gas and Electric Company April 2022

Enclosure PG&E Letter DCL-22-032

1. Introduction Pacific Gas and Electric Company (PG&E) has prepared the 2021 Annual Nonradiological Environmental Operating Report in accordance with the Environmental Protection Plan (EPP), which is Appendix B of Facility Operating License Nos. DPR-80 and DPR-82 for Diablo Canyon Power Plant (DCPP), Units 1 and 2, respectively. The report describes implementation of the EPP per the routine reporting requirements of EPP Subsection 5.4.1. PG&E remains committed to minimizing the environmental impact of operating DCPP.

2. Environmental Monitoring 2.1. Aquatic Issues Aquatic issues are addressed by the effluent limitations and receiving water monitoring/reporting requirements contained in the DCPP National Pollutant Discharge Elimination System (NPDES) permit. The NPDES permit includes applicable requirements of the California State Water Resources Control Board's Ocean Plan and Thermal Plan.

2.1.1. Routine Influent and Effluent Monitoring During 2021, DCPP submitted quarterly NPDES reports containing routine influent and effluent monitoring data and permit compliance summaries to the Central Coast Regional Water Quality Control Board (CCRWQCB). The reports were submitted electronically during the month following the end of each calendar quarter via the California Integrated Water Quality System (CIWQS), an internet database application. DCPP also submitted an annual NPDES report for 2021 to the CCRWQCB in February 2022 via the CIWQS application. The annual report contained monitoring data summaries in tabular and graphical form, and a summary of permit compliance and corrective actions, as applicable, for 2021.

2.1.2. Receiving Water Monitoring Program (RWMP)

The NPDES RWMP, required by the CCRWQCB, included the ecological monitoring, temperature measurements, and State Mussel Watch activities.

Environmental monitoring programs have recorded biological changes in the discharge area since plant start-up. These programs monitor intertidal and subtidal communities of invertebrates, algae, and fish in the discharge cove and at stations north and south of DCPP. During 2021, environmental monitoring continued under the revised RWMP.

The revised RWMP continued historical monitoring tasks, including page 1 of 5

Enclosure PG&E Letter DCL-22-032 temperature monitoring, State Mussel Watch activities, and intertidal and subtidal surveys (with additional stations and increased sampling frequencies).

DCPP submitted the NPDES Receiving Water Monitoring Program:

2020 Annual Report (PG&E Letter No. DCL-2021-514) to the CCRWQCB and the NRC on April 30, 2021. The 2021 Receiving Water Monitoring Program Annual Report will be submitted at the end of April 2022.

During 2021, final resolution of the plant thermal discharge impacts settlement agreement was realized. A public review and comment period was completed in early 2021 for the updated settlement, which had been negotiated between PG&E and the CCRWQCB during 2020.

The settlement addressed impacts on receiving waters from past and ongoing power plant cooling water discharges. The legal agreement between parties was concluded following judicial review and approval by Consent Judgment for Case No. 21CV-0111 dated 05/25/2021 in the California Superior Court, County of San Luis Obispo. Per instructions in the consent judgment, PG&E subsequently completed a payment of

$5,948,419.91 ($5.9 million) to The Bay Foundation of Morro Bay, a third-party administrator of the settlement funds acting on behalf and at the direction of the CCRWQCB.

Regardless of the thermal discharge impacts settlement resolution, the plant NPDES permit remains under administrative extension.

Currently, it is expected that permit renewal will not occur before final shutdown of plant reactor and electrical generating operations in August 2025. Accordingly, modification of the current NPDES permit receiving water monitoring program will likely not occur in the interim period.

2.1.3. Thermal Effects Study DCPP submitted the final thermal effects comprehensive assessment report (PG&E Letter No. DCL-98-585) to the CCRWQCB and the NRC in 1998.

2.1.4. 316(b) Studies DCPP submitted the final 316(b) report, entitled 316(b) Demonstration Report (PG&E Letter No. DCL-2000-514), to the CCRWQCB and the NRC on March 1, 2000.

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Enclosure PG&E Letter DCL-22-032 2.2. Terrestrial Issues 2.2.1. Herbicide Application and Erosion Control Herbicides are used as one component of an overall land vegetation management program that includes transmission line corridors and rights-of-way. The company continues to use only herbicides registered by the Environmental Protection Agency and approved by state authorities, and applies them in accordance with all applicable regulations.

Another component of the vegetation management program is mastication. Mastication is utilized to reduce fuel loads, create fire breaks, maintain line clearance, and increase line of sight in rights-of-ways. Mastication is a vegetation management tool that reduces ground disturbance and is effective at controlling vegetation when used in conjunction with herbicides.

PG&E continues to implement erosion control activities at the plant site and in the high voltage transmission line corridors as part of an overall land management program. These erosion control activities consist of routine maintenance and prevention efforts performed periodically on an as-needed basis, including seasonal storm activity and wildfire damage repair as applicable.

2.2.2. Preservation of Archaeological Resources A. CA-SLO-2 Site Management Archaeological site CA-SLO-2 is managed in compliance with the Archaeological Resource Management Plan (ARMP) and Operating Procedure EV1.ID2. All projects undertaken within site CA-SLO-2, or immediately adjacent, are reviewed to determine whether archaeological deposits associated with the site are present and, if so, an impact assessment is completed. PG&E would invoke the notification and mitigation procedures identified in the ARMP if a project-related impact were identified.

The annual photo-monitoring of CA-SLO-2 was completed on December 21, 2021 by the PG&E Senior Cultural Resource Specialist.

A PG&E Senior Biologist accompanied the Cultural Resource Specialist during the photo-monitoring effort.

The overall condition of site CA-SLO-2 remains stable in locations away from the coastal bluff, with only minor changes observed since the last monitoring event completed in late 2020. Monitoring indicates that the page 3 of 5

Enclosure PG&E Letter DCL-22-032 low soldier-pile retaining wall constructed during 2018 in the west-central portion of the site along a steep road cut is functioning as designed. No new earthen slumping or erosion was observed, and the impacted location has revegetated in the interim. Location specific photographs and a monitoring summary are on file with PG&E. Notable events related to the management of CA-SLO-2 are summarized below.

Kidwell and Linder collected additional information necessary to update the archaeological site record for CA-SLO-2, including photography, mapping, and characterizing prior disturbances based on historical aerial imagery. The information is synthesized in the Enright et al.

2021[1] report as well as the updated site record included as an appendix to the referenced report. The report and updated site record are on file with PG&Es Cultural Resource Specialist.

Archaeological investigation of a portion of CA-SLO-2 was reported in 2021 (Laurie and Jones 2021). The report documents methods and results of limited archaeological excavation undertaken in 2019 in relation to the planned replacement of a 230kV tubular steel pole (TSP) that was ultimately constructed in October 2020. As documented in the 2020 AEOR, the TSP replacement utilized the existing foundation and guy wire anchors, thus avoiding impacts to the confirmed buried archaeological deposits within CA-SLO-2. The report and related updated archaeological site record are on file with PG&Es Cultural Resource Specialist.

B. Northern Chumash Correspondence Representatives of the yak tityu tityu yak tilhini Northern Chumash Tribe of San Luis Obispo County met with PG&E representatives at the CA-SLO-2 site on July 29, 2021 to discuss future Diablo Canyon Plant Decommissioning activities with potential to affect cultural resources.

3. Unusual or Important Environmental Events There were no unusual or important environmental events during 2021.

[1]

Enright, Erin, Jasmine Kidwell, Richard Hanes, Diane Douglas, and Dennis McDougal (2021). Diablo Canyon Decommissioning - Cultural Resource Inventory and Study Plan. Prepared by Applied Earthworks for Pacific Gas &

Electric Co.

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Enclosure PG&E Letter DCL-22-032

4. Plant Reporting Requirements 4.1. EPP Noncompliance There were no EPP noncompliances during 2021.

4.2. Changes In Station Design There were no changes in plant design or operation, tests, or experiments that involved an unreviewed environmental question or a change to the EPP.

4.3. Nonroutine Reports There were no nonroutine events during 2021 per the EPP; therefore, no nonroutine reports were submitted to the NRC.

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