Journal of Engineering and Public Policy
(Vol. 9, August 2002)

Centralized Interim Storage of Nuclear Waste and a National Interim Storage Strategy

By Robert Petroski

Executive Summary

As the recent passage of the Energy Policy Act of 2005 shows, nuclear energy is an important part of U.S. energy policy. The act includes substantial incentives for the development of new nuclear power plants, supporting the expectation that nuclear energy will soon experience renewed growth. However, even as the nation anticipates an expansion in the use of nuclear energy, it must continue providing for the management of nuclear energy’s primary byproduct: highly radioactive spent nuclear fuel.
Because spent nuclear fuel remains radioactive for hundreds of thousands of years, it must be properly stored and disposed of in order to prevent harm to the public or the environment.

While plans to develop a geologic repository for permanent disposal exist, delays in that project have necessitated the continued use of interim storage. Interim storage is defined as spent fuel storage between the time spent fuel leaves a reactor and the time it is disposed of.

The first five years of interim storage for spent fuel necessarily occur in a spent fuel pool at the generating site, which allows time for the spent fuel to cool and become less radioactive. After this initial five year period, spent fuel may be transferred to aboveground dry cask storage. Existing dry cask storage is located almost exclusively at reactor sites, because it was originally instituted in order to meet immediate and local interim storage needs. However, considerable benefits can be realized by establishing dry cask storage at a centralized storage facility, then transporting spent fuel from multiple reactors to the centralized site. This interim storage arrangement is known as centralized interim storage.

Centralized interim storage, through economies of scale, can provide interim storage at a lower cost than dry cask storage at at-reactor sites. While use of centralized interim storage would increase the amount of spent fuel transportation required, the resulting increase in transportation cost is in many cases less than the savings obtained by the lower storage cost. Therefore, the use of centralized interim storage as an alternative to at-reactor dry cask storage can lower the system cost of interim storage.

Centralized interim storage also allows spent fuel to be removed from shutdown reactor sites. This is significant because the cost of storing spent fuel at a shutdown site is extremely high compared to the cost of storing spent fuel at a centralized interim storage facility. Because interim storage must continue until a disposal facility becomes available, an unknown period of time, use of centralized storage in this manner substantially reduces the economic uncertainty of interim storage. In the same way, centralized interim storage can also greatly reduce economic pressure to create a permanent repository.

Centralized interim storage can also insure against the possibility of early plant closure by providing guaranteed access to interim storage. This can potentially prevent the loss of billions of dollars in electrical generation at reactor sites with limited access to on-site interim storage.

Finally, centralized interim storage does not significantly differ from at-reactor storage in terms of safety and security. Dry cask storage at any site is very safe and secure due to the extremely robust construction of the storage casks, as well as the significant defenses employed at all nuclear facilities. The increase in spent fuel transportation due to centralized interim storage creates only a small additional risk.

Despite its advantages, centralized interim storage has not been implemented largely due to policy barriers. In particular, the primary policy barrier that has prevented the federal government from instituting centralized interim storage is the concern that federal interim storage would interfere with the creation of a permanent geologic repository. Also, it is difficult to find a suitable site for centralized interim storage because of significant state and local opposition to hosting a large spent fuel storage facility.

The best means to realize centralized interim storage benefits in the near term is the institution of a private centralized interim storage facility, such as the Utah facility proposed by Private Fuel Storage, a consortium of nuclear utilities. By leaving interim storage of existing spent fuel in the hands of utilities, the creation of a private centralized facility sidesteps some of the policy issues that restrict federal interim storage. Federal support of a private centralized interim facility, in the form of legislative backing and transportation assistance, can facilitate the implementation of centralized interim storage and encourage its use by utilities. This in turn would produce the benefits of centralized interim storage outlined above.

While a private centralized interim storage facility would be beneficial in the near term, there is a greater incentive for the federal government to establish federal centralized interim storage in the long term. With a federal centralized interim storage system, the federal government will be able to guarantee acceptance of spent fuel generated at future nuclear reactors prior to the development of a permanent geologic repository. Doing this would remove one of the primary uncertainties facing nuclear utilities and encourage additional investment in nuclear energy. Furthermore, a fully centralized system would eliminate the need for at-reactor dry cask storage, thus optimizing system costs.

Ultimately, fully-centralized interim storage will normalize interim storage costs and allow for the unhurried, careful implementation of permanent disposal facilities. It can then greatly facilitate disposal once such facilities are available.

The federal government should therefore adopt a two-stage interim storage strategy: support private centralized interim storage to service existing reactors in the near term, and then implement a fully centralized federal interim storage system to service future reactors in the long term. Doing so would ensure that interim storage can best serve its purpose: to safely, securely, and cost effectively store spent fuel so that the best permanent disposal options can be implemented.

 

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