Nuclear Waste at San Onofre

Andrew Chun
November 23, 2020

Submitted as coursework for PH240, Stanford University, Fall 2020

Nuclear Waste

Fig. 1: This image shows what the plant looks like and where it is situated. (Source: Wikimedia Commons)

Of the many viable sources of energy these days, including solar, hydroelectric, wind, biofuels, and others, one of the most controversial is nuclear energy. Generally speaking, nuclear power plants harness the energy released from fission to create steam and power generators (which in turn create electricity). While there are many advantages to using nuclear power for the future of energy, one of the most significant downsides has to do with nuclear waste and the disposal of spent nuclear fuel. [1] In general, there are three types of nuclear waste: low level, intermediate level, and high level. While getting rid of lower and intermediate level waste is relatively straightforward, with those types being sent to depositories in South Carolina, Utah, Washington or Texas, disposing of higher level nuclear waste is a much bigger issue. [1]

High Level Nuclear Waste

Some nuclear waste is classified as high level nuclear waste (HLW) due to its hazardous level of radioactivity. If this type of waste is not disposed of or stored in the right way, the radioactivity, specifically the gamma rays emitted from the waste, can cause health problem (including cancer and death) to people who are in the vicinity. Because of this, high level waste, in its disposal (and transport), must be shielded in addition to being cooled. [2] In practice, there are few main ways that this type of waste is disposed of including geological disposal, transmutation, and waste reprocessing. [3] It is important to note that these are long term storage options that allow the radioactive materials to decay over many, many years. As will be touched upon in the next section, there are also short term methods of storage.

San Onofre

In getting to the secondary topic of this paper, the issue with the San Onofre Nuclear Generating Station (SONGS for short) is that a great deal of the spent nuclear fuel rods were still located on site in short term storage after it was decommissioned in 2013. At that time, of the 1,631 tonnes of spent fuel located on site, about 1,099 tonnes were located in two reactor pools (known as wet storage), which were neither meant to hold that amount of fuel nor for an extended period of time. [4] The other type of storage being used, known as dry storage, only housed about 430 tonnes of the fuel, but was considered much safer long term for on site waste storage. [4] Over the past few years, the fuel that was in wet storage was carefully transferred into dry storage, finally wrapping up in the summer of 2020 when the last canister of dry storage was filled. [5] For many who worry about the wastes harmful effect on the surrounding area, this was viewed as a step in the right direction but there is still cause for concern, especially given that the plant is in an earthquake-prone location. [6] As can be seen from Fig. 1, the plant is located along the ocean but also right next to a heavily trafficked part of the I-5 freeway that connects San Diego and Los Angeles. This makes the waste that is stored there an important issue in the community with as the location of the plant is far from desolate. The next step is to relocate the dry storage to an off-site repository, but currently there is no place for it to go as the federal government has not built any such place. [5]

© Andrew Chun. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] A. Hellman, "What to do with Nuclear Waste," Physics 241, Stanford University, Winter 2019.

[2] R. C. Ausness, "High-Level Radioactive Waste Management: The Nuclear Dilemma," Wis. L. Rev. 1979, 707 (1979).

[3] S. Ali, "Nuclear Waste Disposal Methods," Physics 241, Stanford University, Winter 2011.

[4] R. Alvarez, "Storage of Nuclear Waste From Spent Fuel at San Onofre," Friends of the Earth, 25 Jun 13

[5] N. Nikolewski, "Final Canister of Nuclear Waste Transferred to Storage Facility at San Onofre," Los Angeles Times, 8 Aug 20.

[6] B. Bonanni, "San Onofre Nuclear Generating Station," Physics 240, Stanford University, Fall 2016.