PG&E Corporate Responsibility and Sustainability Report 2018

Northern California Wildfires

Nuclear Operations

Diablo Canyon Power Plant is a safe, clean, affordable and reliable energy resource for California, generating enough carbon-free energy to meet the needs of more than 3 million people. Diablo Canyon also serves as one of the main employers and buyers of goods in the San Luis Obispo County region.

Our Approach

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.

Demonstrating Earthquake, Flooding and Tsunami Safety

Extensive analyses performed at the direction of the NRC continue to show that Diablo Canyon can safely withstand extreme natural events, including potential earthquakes, tsunamis and flooding. The analyses used the latest regulatory guidance, scientific methods and models, site-specific information and independent expertise to re-evaluate the impacts that earthquakes, large waves and flooding could have on the facility. The updated findings represent the culmination of years of study and analysis, and further confirm the safety of the plant’s design.

The updated seismic assessment represents a more extensive evaluation of the seismic hazard than previously performed. Using the NRC’s Senior Seismic Hazard Analysis Committee process, independent seismic experts publicly re-evaluated existing and new seismic information to re-evaluate how earthquakes could potentially impact the facility. The result provides additional confirmation that the plant is seismically safe.

The assessment also informs PG&E’s Long-Term Seismic Program, led by a geosciences team of professionals that partners with independent seismic experts on an ongoing basis to evaluate regional geology and global seismic events to ensure that the facility remains safe.

PG&E’s flooding hazard re-evaluation determined that the plant’s key safety systems and components continue to be safe from tsunamis, including those generated from underwater landslides and earthquakes.

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 wet storage facilities. These on-site storage systems are 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. The ability to store spent fuel safely on-site, however, should not be a long-term alternative to the federal government assuming its responsibility to accept the fuel for permanent storage. To that end, PG&E will continue to advocate that the federal government meet its commitment and take charge of managing the nation’s spent fuel.

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.

2017 Milestones

In a typical year, at least one of Diablo Canyon’s two reactor units safely undergoes a planned refueling and maintenance outage. Once every five years, both units undergo a planned refueling and maintenance outage, due to their separate operating schedules.

In 2017, Unit 1 at Diablo Canyon underwent a safe and successful refueling and maintenance outage.

PG&E also continued with the decommissioning of the former nuclear unit at the Humboldt Bay Power Plant. PG&E has completed removal of prior operational nuclear systems and equipment, as well as demolition and removal of many structures on-site. Final site restoration and remediation efforts continue.

Measuring Progress

Nuclear Power Plant Performance
Average Capacity Factor Footnote 1
2015 94%
2016 96%
2017 91%
  • 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

Diablo Canyon continues demonstrating high operational performance as gauged by its plant capacity factor, a measure of generation reliability. During 2017, Diablo Canyon achieved a capacity factor of 91 percent, which was lower than in previous years due to large capital projects that extended a planned refueling outage.

Diablo Canyon is a vital local economic engine and brings significant benefits to San Luis Obispo and Northern Santa Barbara counties. Planned refueling outages can bring almost 1,000 temporary workers to the Central Coast, where they spend money on local housing, dining and shopping.

Beyond these temporary jobs, PG&E is the largest private employer in the area, with nearly 1,500 workers and operations that contribute more than $900 million to the region through the funds that we directly spend and the subsequent economic activity in the community from those investments. Tax revenues from the plant—the largest property tax payer in San Luis Obispo County—help fund schools, public works projects, public safety, and health and other vital services.

Looking Ahead

Bridging to California’s energy future

California’s energy landscape is changing dramatically. 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 (DCPP) past 2025.

Reflecting this change, PG&E partnered with labor and leading environmental organizations in 2016 on a joint proposal that would increase investment in energy efficiency and renewables while retiring DCPP at the end of its current NRC operating licenses, which expire in 2024 and 2025.

The parties to the DCPP joint proposal include PG&E, International Brotherhood of Electrical Workers Local 1245, Coalition of California Utility Employees, Friends of the Earth, Natural Resources Defense Council, Environment California, California Energy Efficiency Industry Council and Alliance for Nuclear Responsibility.

Key elements of the joint proposal

The parties jointly proposed that DCPP be replaced with a cost-effective, greenhouse gas-free portfolio of energy efficiency, renewables and other clean energy resources.

Recognizing that the procurement, construction and implementation of this greenhouse gas-free portfolio would take time, the joint parties agreed to support PG&E in obtaining the state approvals needed to operate DCPP to the expiration of its current NRC operating licenses.

This avoided an early shutdown of DCPP and associated negative economic and social impacts, including replacing the plant’s output required to meet customer demand with non-greenhouse gas-free resources.

As part of the joint proposal, PG&E immediately ceased any efforts on its part to renew the DCPP operating licenses, and asked the NRC to suspend consideration of the pending license renewal application. PG&E also committed to withdrawing the application upon CPUC approval of the joint proposal.

PG&E does not believe long-term customer rates will increase as a result of the joint proposal.

Support for employees and the community

The joint proposal proposed support for a successful transition for DCPP employees and the greater San Luis Obispo County community.

The $85 million community impact mitigation program would support the community with its transition and provide funding to support essential public services that the plant and the local community rely upon.

The DCPP employee program would provide 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 company.

Current status

The CPUC authorized several elements of the joint proposal in January 2018, including approval to cease plant operations once the NRC operating licenses expire, and funding for employee retraining and redeployment. The CPUC also expressed its intention to avoid any increase in greenhouse gas emissions resulting from the closure of DCPP.

Full funding of the employee retention program was not approved as part of the CPUC’s decision. It also expressed that legislative authorization would be needed to approve the community impact mitigation program.

Senate Bill (SB) 1090 was introduced in the California State Legislature to meet these key remaining goals of the joint proposal. It was approved by the State Senate and State Assembly in 2018 with bipartisan support, and was signed into law by Governor Brown in September 2018.