Nuclear Operations

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

Our Approach

While Diablo Canyon Power Plant 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 Diablo Canyon. 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 employees 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. This on-site storage system is safely used at nuclear power plants around the world. 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.

2019 Milestones

In 2019, both Unit 1 and Unit 2 at Diablo Canyon underwent safe and successful refueling and maintenance outages. The Unit 2 stator was successfully replaced during the unit’s planned outage; this key component of the generator puts out 1,143 megawatts of greenhouse gas-free electricity into the western 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.

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 both units underwent a planned refueling and maintenance outage, Diablo Canyon achieved a capacity factor of 83 percent during 2019.

Nuclear Power Plant Performance
Average Capacity Factor^{Footnote 1}
2016	96%
2017	91%
2018	93%
2019	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 2019, both units underwent a planned refueling and maintenance outage, which occurs approximately every five years. Additionally, the refueling outage on Unit 2 was a planned extended outage that 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 Employees and the Community

The CPUC granted PG&E 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 employee retention, retraining and redeployment, as well as $85 million for a community impact mitigation program.

The Diablo Canyon employee program provides incentives to retain employees 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 $28 million was distributed to the County of San Luis Obispo in 2019; remaining funds will be disbursed annually through 2025.

Current status

Nothing is more important than the safety of our employees, customers and the communities we serve. 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 2020