Report Urges Storing Spent Nuclear Fuel, Not Reprocessing It

 

The challenge at the Fukushima Daiichi plant in Japan involves not only damage to three reactors but also the loss of cooling water in at least one pool of spent radioactive fuel, which prompted some American experts to recommend an evacuation to a radius of 50 miles. And that pool was not loaded nearly as heavily as pools at similar reactors in the United States.

In a study to be released on Tuesday, engineers and scientists at the Massachusetts Institute of Technology therefore suggest that “the entire spent-fuel management system — on-site storage, consolidated long-term storage, geological disposal — is likely to be re-evaluated in a new light because of the Fukushima storage-pool experience.”

The accident in Japan has already generated calls for sending the fuel to factories where it would be mechanically chopped up and chemically dissolved to recover the plutonium that is made in routine reactor operations, as it frequently is in Europe and Japan. The plutonium could then be used as a substitute for uranium fuel at nuclear plants.

But in the M.I.T. report, experts argue that there is no reason to find a substitute for uranium because the existing global supply is plentiful. In fact, there is enough uranium available to fuel 10 times as many reactors as exist today, even if each of the new ones ran for 100 years, the study says.

Rather than processing the fuel to retrieve plutonium, the report suggests, the fuel should be “managed” so that the option of doing so is preserved — perhaps by storing the fuel in above-ground silos for a century. It recommends moving it to a centralized repository, starting with fuel from nuclear reactors that have been retired and torn down.

A summary of the report released last fall also made that point, but the conclusion is likely to gain far more attention in coming months as federal regulators and Congress awaken to the potential for an accident involving spent fuel.

Congress chose Yucca Mountain, a site in the Nevada desert, as the top candidate for a nuclear waste burial site in 1987, but President Obama shut down an Energy Department program to develop the repository and appointed a commission to study alternatives, including reprocessing. The panel is expected to issue a preliminary report this spring.

Also standing in the way of Yucca is the Senate majority leader, Harry Reid, Democrat of Nevada, who has effectively blocked money for the program.

The M.I.T. study also raises the idea of storing more waste in small steel and concrete silos, known as dry casks, in a central area with low population density. All the spent fuel produced so far would fill an area under 300 acres, experts say.

Another alternative for nuclear waste disposal is to build a new class of reactors powerful enough to break up the elements that are hardest to dispose of: materials that are created in reactors and remain significantly radioactive for tens of thousands of years. But that would require development of new technologies at a substantial cost and, like reprocessing, would carry a risk of releasing radioactive contaminants from fuel that is now mostly packaged in compact and airtight forms.

The new reactors and conventional reprocessing would each create a waste stream for which a repository would be needed anyway, the scientists add. The executive director of the M.I.T. study, Charles W. Forsberg, said the Fukushima accident would therefore “place more emphasis on getting a geological repository program up and running.”

All the same, engineers involved in the Yucca Mountain project say that even if Congress could be persuaded to authorize money for a permanent repository, it would be a few years before the government could decide whether the site was suitable and many more years before it could absorb a major fraction of the waste now sitting at reactor sites.