Thomas Gardiner
While the U.S. government seeks a permanent home for tens of thousands of tons of spent nuclear reactor fuel, the waste can safely be stored at the power plants that generated it, the head of the Nuclear Regulatory Commission said recently.
“The NRC has concluded that storage of spent fuel at reactor sites (and at away-from-reactor sites) can safely continue until a repository becomes available,” commission Chair Kristine Svinicki wrote in a Nov. 14 letter to Rep. Darrell Issa (R-Calif.).
Used fuel has been maintained “safety and securely” in wet or dry storage for decades at nuclear facilities, according to Svinicki. The NRC, meanwhile, monitors storage systems in order to promptly identify any problems that develop and to prepare appropriate responses, she added.
Svinicki was responding to an Oct. 17 letter from Issa regarding concerns about on-site storage of spent fuel at the shuttered San Onofre Nuclear Generating Station (SONGS) in his Southern California congressional district. The lawmaker forwarded a list of questions about SONGS’ independent spent fuel storage installation (ISFSI), which primary plant owner Southern California Edison (SCE) plans to expand to hold all of the site’s spent fuel.
The questions were developed by Rita Macdonald and Bart Ziegler of the Del Mar, Calif.-based Samuel Lawrence Foundation, which pressed for SONGS’ closure and has sought to ensure effective storage of its nuclear waste.
The plant’s reactor Unit 1 shut down in 1992, while Units 2 and 3 were taken permanently offline in 2013 due to problems with replacement steam generators. All spent fuel from the three reactors is intended to go into dry storage.
The ISFSI is located between a major interstate and the Pacific Ocean, in an earthquake-prone area only about 100 feet from the shoreline. Concerns over public health and environmental safety led the nongovernmental watchdog group Citizens’ Oversight, of El Cajon, Calif., to challenge the California Coastal Commission’s 2015 approval of SCE’s storage plans.
The 2016 lawsuit was settled in August in San Diego Superior Court. The settlement directs Southern California Edison to use “commercially reasonable efforts” to move the SONGS spent fuel to another site, possibly to the partially SCE-owned Palo Verde nuclear plant near Phoenix, Ariz.
Southern California Edison is legally bound by the settlement to ask about moving the SONGS fuel to Arizona, but Palo Verde’s primary owner, Arizona Public Service, has said it would not take the waste because of licensing issues. If no alternatives manifest themselves, SCE plans to store the fuel on-site at SONGS indefinitely — or at least until it can be moved to a temporary or permanent nuclear-waste repository, such as the proposed Yucca Mountain site in Nye County, Nev.
Under the 1982 Nuclear Waste Policy Act, the Department of Energy is required to build a permanent resting place for what is now more than 75,000 metric tons of spent fuel stored around the country. There has been little progress over the decades.
The Trump administration has requested $150 million in fiscal 2018 for the NRC and Energy Department to resume the license application process for Yucca Mountain. The House has supported the request, while Senate appropriators have so far zeroed out any funding for the project. Congress has yet to pass a full-year budget for fiscal 2018, which began on Oct. 1.
Several of the questions from Macdonald and Ziegler addressed storage cask design and reliability at SONGS. Roughly 400 used fuel assemblies from reactor Unit 1 are already in dry storage in containers manufactured by French nuclear giant AREVA. The remaining 2,668 assemblies from Units 2 and 3 are in wet storage, and due to be placed into dry storage in Holtec containers by 2019.
Ziegler has for years criticized the planned use of thin-wall canisters to store the remainder of SONGS’ used fuel, urging the NRC in a 2015 letter to use thick-wall containers he said would provide greater protection of the nuclear waste. His letter with Macdonald asked why the NRC approved the use of thin-wall containers at SONGS while authorizing thick-wall containers for seven other nuclear plants.
In an Nov. 16 response, NRC staff noted that licensees select the storage system to be used at their facilities and the agency confirms that they meet all regulatory requirements.
“The Holtec and Areva systems have been reviewed and, after determining that the systems meet all applicable requirements so that fuel would be stored safely, approved by the NRC,” commission staff wrote.
Ziegler and Macdonald also asked for details about the security of SONGS’ waste containers against threats including terrorism, earthquakes, and tsunamis.
“All dry cask storage systems approved by the NRC for use at ISFSIs, including the Holtec and Areva systems used or proposed for use at SONGS, must be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, lightning, hurricanes, floods, tsunami, and seiches, without impairing their capability to perform safety functions,” NRC staff responded.
