SONGS decommissioning makes progress

Lucette Moramarco

Associate Editor

Manuel Camargo, principal manager of the San Onofre Decommissioning Project, attended the Feb. 16 Community Forum meeting to present information on the project which is halfway done.

The overall goals of the project include safety, stewardship and engagement. Its mission is to conduct the decommission in a safe, timely, transparent, and cost-efficient manner while maintaining high standards of environmental protection.

According to Southern California Edison's website, "Decommissioning is a well-defined NRC (Nuclear Regulatory Commission) process that involves safely transferring the used nuclear fuel into storage, followed by the eventual removal and disposal of radioactive components and materials from the site. Any residual radioactivity will be reduced in a manner and to a level that is safe for unrestricted use by SCE's employees and the public. This will support the termination of SCE's NRC license and return of site to its owner, the U.S. Navy." (https://www.songscommunity.com/about-decommissioning

Unit 1 at the San Onofre Nuclear Generating Station (SONGS) went online in January 1968, was retired in 1992 and partially decommissioned. Units 2 and 3 went online in November 1983 and April 1984, respectively, and were both retired June 7, 2013. After much planning and paperwork, the work of dismantling SONGS began early in 2020.

Spent fuel has been removed from cooling pools and moved into the Independent Spent Fuel Storage Installation which consists of two systems that provide passive dry cask storage for the spent fuel while on site.

Camargo explained that spent nuclear fuel is not what many people think it is (green liquid), but it is actually ceramic uranium dioxide fuel pellets. "Those pellets are in a solid, ceramic format, requiring 5,000 degrees Fahrenheit to melt. That's hotter than molten lava and approximately half the temperature of the surface of the sun. And with the spent fuel at SONGS in passive, dry cask storage, we cannot produce anywhere near those heat loads."

According to Camargo's presentation, the pellets have been cooling since 2012 and the decay heat of the hottest fuel assembly is comparable to a hair dryer (~1500W). The pellets are sealed within corrosion-resistant zircaloy rods ("cladding") which are encased in stainless steel canisters pressurized with inert helium.

The robust storage canisters are made of 5/8" stainless steel, 316L for corrosion resistance. The welds are laser-peened with a seismic rating of 1.5 g. They can also withstand inundation in 50-125 feet of water. Their service life is more than 100 years.

Camargo said, "I should add that the point is, with all spent fuel in passive dry cask storage, there are no credible accident scenarios in which radiological material can leave the site boundary. That should give comfort to folks in Fallbrook/Bonsall, and even those who surf at San Onofre or soak in the sun on the neighboring state beach."

Still, there is a coalition advocating for offsite storage/disposal in an effort to promote action by the federal government into moving forward in the development of a safer way to store the spent fuel. Anyone interested in joining can sign up at http://www.spentfuelsolutionsnow.com.

That coalition, Action for Spent Fuel Solutions Now, is holding a webinar series which includes a panel discussion on best practices for spent fuel disposal, including experts from Finland, Sweden, and Canada who are ahead of the United States in dealing with this issue.

The panel discussion will be on Thursday, March 23, at 8 a.m. Details are pending at http://www.spentfuelsolutionsnow.com/events and upcoming webinar topics include the Department of Energy's consent-based siting effort and funding opportunity; Transportation of spent fuel, and Designs for interim storage and disposal facilities.

Residents can stay informed about the progress at SONGS by going to https://www.songscommunity.com/ for information on Public Walking Tour dates and sign ups, a decommissioning blog and news updates and SONGS monthly update email as well as links to its social media accounts.