Nuclear Operations

PG&E’s Diablo Canyon Power Plant generates safe, clean, affordable and reliable carbon-free energy to meet the needs of more than 3 million Californians.

Our Approach

While Diablo Canyon’s Units 1 and 2 will close in 2024 and 2025, respectively, we remain strongly committed to the highest levels of safety, performance and security at the facility. The Nuclear Regulatory Commission’s (NRC) latest annual assessment of the facility places Diablo Canyon among the highest-performing plants in the U.S. nuclear industry. This reflects the hard work and dedication of our coworkers and our commitment to meeting PG&E’s and the NRC’s high-performance standards.

Spent Fuel Storage

At both Diablo Canyon and PG&E’s former nuclear unit at the Humboldt Bay Power Plant, PG&E safely stores spent fuel in on-site dry cask storage systems approved and licensed by the NRC. Diablo Canyon also safely and securely stores spent fuel in a wet storage facility. These two on-site interim storage solutions are federally monitored and follow industry best standards to ensure that they are safe and effective.

Water Management

PG&E actively manages the water used in the electric generation process in accordance with the water discharge limit set by Diablo Canyon’s Clean Water Act permit.

2020 Milestones

In 2020, Diablo Canyon Unit 1 underwent a safe and successful refueling and maintenance outage. Unit 2 experienced several generator maintenance outages. Each unit produces 1,143 MW of greenhouse gas-free electricity into the energy grid during regular operations.

PG&E also continued decommissioning the former nuclear unit at the Humboldt Bay Power Plant, where site restoration and remediation efforts are in the final phase.

Land Stewardship at Diablo Canyon

PG&E’s Diablo Canyon Power Plant is located on 14 miles of scenic coastline and surrounded by 12,000 acres of sensitive habitat, productive ranches and panoramic open spaces.

Through collaborative measures, the Diablo Canyon Land Stewardship Program, run by PG&E coworkers, works to protect and manage the lands and resources of this stunning coastline. Together, this group closely monitors our land use, manages programs to provide visitors with access to the Pecho Coast and Point Buchon trails and facilitates scientific research.

Through these activities, PG&E is demonstrating a commitment to effective land management by studying biodiversity, managing grazing and wildland fuels on the property, inventorying sensitive resources, managing cultural resources and protecting sensitive habitats. Examples include:

Managing wildland fuels using mechanical removal and partnering with the California Department of Forestry and Fire Protection to promote prescribed burns on the property.
Protecting the biodiversity and health of the local ecosystem by inventorying and treating invasive weeds.
Promoting a healthier rangeland habitat that sustains native plant species and reduces the growth and spread of invasive plant species in collaboration with local universities.

Measuring Progress

Diablo Canyon continues to demonstrate high operational performance as gauged by its plant capacity factor, a measure of generation reliability. Despite being a year when Unit 1 underwent a planned refueling outage and Unit 2 had three maintenance outages, Diablo Canyon achieved a capacity factor of 83% during 2020.

Nuclear Power Plant Performance
	Average Capacity Factor^{Footnote 1}
2016	96%
2017	91%
2018	93%
2019	83%
2020	83%^{Footnote 2}

1. Refers to the ratio of the actual output of the plant relative to the output if the plant had operated at full capacity for the year.¹
2. In 2020, Unit 1 underwent a planned refueling outage, which occurs approximately every 18 months. Additionally, Unit 2 had three generator maintenance outages that, combined, lasted more than 80 days.²

Bridging to California’s Energy Future

State policies that focus on renewables and energy efficiency, coupled with projected lower customer electricity demand in the future, will result in a significant reduction in the need for the electricity produced by Diablo Canyon Power Plant past 2025.

However, the continued safe and reliable operation of the plant is needed through 2025 to support California in achieving its clean energy goals. PG&E will participate in the CPUC’s Integrated Resource Planning process to shape our future energy portfolio to meet California’s clean energy goals in a reliable and cost-effective manner.

Support for Coworkers and the Community

The CPUC granted the Utility approval to cease plant operations once the NRC operating licenses expire. The CPUC and the state legislature (through Senate Bill 1090) authorized ratepayer funding for coworker retention, retraining and redeployment, as well as $85 million for a community impact mitigation program.

The Diablo Canyon employee program provides incentives to retain coworkers during the remaining operating years of the plant, and a retraining and development program to facilitate redeployment of a portion of plant personnel to the decommissioning project or other positions within the utility.

The community impact mitigation program is meant to ease the local public health, safety and economic impacts of the closure of Diablo Canyon and to provide funding to support essential public services that the local community relies upon. More than $9 million was distributed to the County of San Luis Obispo in 2020; remaining funds will be disbursed annually through 2025.

Current Status

PG&E is focused on the continued safe and reliable operation of Diablo Canyon through the end of its operating licenses while preparing for a safe and successful decommissioning.

Corporate Responsibility and Sustainability Report 2021