Decommissioning Work Progresses at San Onofre Nuclear Plant

Initial planning and preparation sets the stage for demolition to begin in the next two years.

June 05, 2015 | By Mary Ann Milbourn

In June 2013, Southern California Edison (SCE) announced that the San Onofre nuclear plant near San Clemente would be retired after more than 40 years of generating electricity for Southern California.

The plant’s last two operating units had been shut down the previous year after station operators detected a small leak in a tube inside a steam generator manufactured by Mitsubishi Heavy Industries. With the permanent closure decision, the 20-year task of decommissioning the facility began.

During the last two years, Tom Palmisano, SCE vice president of Decommissioning and chief nuclear officer, and his team have been laying the groundwork for the decommissioning of the plant. This includes the safe storage of the used nuclear fuel on site — at least for now — the dismantling of the buildings and the restoration of the land so it can be returned to the U.S. Navy.

Although a lot of that preparatory work is not visible to the public, like powering down the plant equipment and removing hazards, such as 200,000 gallons of oil, the decommissioning plan is well underway.

Palmisano recently sat down in his San Onofre office to talk about where the project stands and what to expect going forward.

Q. Where are you now in the decommissioning process?

A. We’ve been doing a lot of planning and a lot of preparatory activities. We have obtained state approvals to undertake some physical modifications to the plant to prepare it for decommissioning, but we have not actually started the dismantlement of the plant.

Everything we are doing is grounded in our decommissioning principles of safety, stewardship and engagement. The most visible effort of the past year has been our close working relationship with the San Onofre Community Engagement Panel, made up of area community and elected officials.

Q. With the reactors no longer operating and permanently defueled, will the emergency plan be changing?

A. The emergency planning is changing because most potential accidents related to an operating plant are no longer possible at shutdown nuclear plants such as San Onofre, where fuel has been removed from the reactor. However, the revised emergency plan will maintain many of our current emergency planning elements. We continue to protect the public and the employees. We have the ability to notify the local authorities of any emergency on site and communicate to the public. We continue to do exercise drills and perform other activities.

Q. What is the plan for the storage of used nuclear fuel on site?

A. We have used nuclear fuel stored in the dry cask storage system. We also have it stored in what’s called wet storage in two spent fuel pools. All that fuel eventually will be moved out of the wet pools into dry cask storage. It will be on site until the U.S. Department of Energy removes the fuel.

Q. What about interim storage off-site?

A. Right now, it is a federal government responsibility, which lies with the U.S. Department of Energy to develop a permanent repository.

There is recent interest in developing what is called an interim storage facility particularly in West Texas or New Mexico. A couple of private companies indicated they would be interested in developing this, which may provide an avenue to ship San Onofre fuel for interim storage off-site, but that is going to likely require some federal legislation. So it’s a great concept that we certainly encourage. It’s not clear to us whether that’s going to be viable.

It’s important for us to reinforce that we are going to store fuel safely for as long as it’s here. We’re responsible for it and we will fulfill our responsibilities. We will continue to advocate that the U.S. Department of Energy and the federal government fulfill their legal responsibilities to develop a disposal solution and take the fuel off-site.

Q. What can people expect in the near future?

A.  Over the next year, not a lot will be very visible. Again, we are finishing the planning and preparatory stages. Over the next one to two years, I would expect to see us expand the independent spent fuel storage installation which is also called the dry cask storage installation. The major dismantlement is probably two, two-plus years out. So most of the physical changes to the site are going to be two or more years from now.

Q. After the buildings are dismantled, what happens to the material?

A.  Generally, the radioactive materials are appropriately packaged and shipped to a radioactive waste facility in Utah or in Texas. Non-radioactive materials from a general decommissioning plant will be disposed of in a landfill outside of California. In other words, all of our material will be shipped out of state and disposed of as radioactive material or as non-radioactive material in an appropriate facility.

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