What should we do with nuclear waste?

The report’s recommendation in effect would create two approaches for nuclear waste management and disposal: commercial spent fuel would be the responsibility of a utility-owned corporation and defense waste would remain the responsibility of the federal government. If both succeed, great. If one succeeds, that may open the door to the success of the other. As an example, the high‑level waste from defense programs might finally be accepted for disposal at the commercial repository for a fee. 

Garthwaite: What are some of the implications of transferring responsibility from the government to the utilities?
Ewing: According to the Nuclear Waste Policy Act of 1982, the federal government was to take ownership of the used nuclear fuel from the utilities in 1998. In the absence of a geologic repository, the government was not able to take ownership of the fuel, which now accumulates at reactor sites across the country. The utilities have sued the government and have won a settlement to cover the cost of their continued storage of the fuel at reactor sites. This settlement costs the taxpayer some $500 million a year with the total costs over time reaching some tens of billions of dollars.  

The utilities package and store the fuel in ways that are economical from their perspective, but the result may well be packages that are unsuitable for transportation and disposal. In other words, there is a huge disconnect in the backend of the nuclear fuel cycle in the U.S. Our proposal to put the utilities in charge of the handling, transportation and disposal of the fuel removes many of these disconnects. 

Garthwaite: One of your group’s recommendations is for communities to volunteer to host a nuclear waste repository, or at least accept it. What are some of the reasons that a community would volunteer for this?
Ewing: We have communities that are very interested in the opportunity for economic development. The downside is you don’t want communities volunteering just because they need the economic stimulus. The goal is to identify a technically defensible site near a community that understands why the site is suitable and safe. In Sweden and Finland, the repositories are located near communities that also have nuclear reactors and a good understanding of nuclear safety.

Garthwaite: Can communities ever really get a complete picture of what it will mean to host one of these repositories, given uncertainty about how these materials and sites will behave in the distant future? What are some of the technical and scientific challenges that must be overcome if this waste is going to be stored permanently?
Ewing: One of the points we make in the report is that the present regulatory framework extends over evolutionary timescales – out to one million years. In the U.S. there’s a heavy emphasis on a quantitative, probabilistic risk assessment, which calculates risk out to a million years in order to determine whether a site complies with regulations. But in the report, we strongly endorse a different approach, the safety case, which has been used in other countries.

The safety case goes beyond calculations and includes qualitative assessments of safety, particularly over long time periods. With such an approach, the determination of safety does not rest on the calculations, but rather on a compelling argument for safety.  As an example, locating a repository in an area with very old rocks, hundreds of millions of years old, can be one of the arguments for the long-term stability and safety of the site over one million years.

Garthwaite: In a best-case scenario where this does move forward and goes through all steps that you would hope for, how long will this endeavor take?
Ewing: Beginning from scratch, the identification and characterization of a site, the design and construction of the repository and the licensing process can take as much as 40 to 50 years. Once the repository begins to receive waste, it will continue operation for up to 100 years, given the amount of waste the U.S. can expect to accumulate. At that point, we would expect the repository to be sealed permanently. 

Sometimes colleagues have said, “We put a man on the moon, the Manhattan Project created the first nuclear weapons – why can’t we site and build a geologic repository?” My answer is that this is a very different type of activity – one that requires creative and rigorous science and engineering and careful attention to the social aspects of the process. In this field one has to be prepared to deal with a changing political environment and a skeptical public.  This is why trust is such an essential characteristic of any organization dealing with nuclear waste.