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What is dry cask nuclear waste storage?


Q. My question has to do with Yucca Mountain, which is proposed to be the nation's first nuclear waste dump site. Building the site is now supposed to cost taxpayers $32 billion more than was originally estimated, so a lot of Utah residents I know are understandably upset about the increased price tag, and insisting that storing nuclear waste on site in "dry cask" storage would be safer and more effective. What exactly is dry cask storage, and would it really better than storing nuclear waste at Yucca Mountain? – Sandy, UT

A. Right now, there are two methods of storing nuclear waste. One involves storing spent (toxic) fuel at the bottom of large concrete steel-lined pools while it cools—a process that takes anywhere from one to five years. The other method is dry cask storage, which involves storing cooled fuel in large, heavy steel cylinders that sit above ground and provide leak-tight containment.  

The Nuclear Regulatory Commission says that both methods are safe and effective for temporary nuclear waste storage, according to Scott Burnell, NRC spokesperson. But the key word here is “temporary.” Though the dry casks can last for decades, the more than 130 nuclear waste storage sites spread across 39 states were never meant to provide permanent storage. That’s where Yucca Mountain comes in. Nuclear waste storage in Yucca would essentially use the same type of casks mentioned above—except larger and designed to last for thousands of years. Another key difference is that the casks would literally be stored under the mountain—about a thousand feet deep. Plus, nobody lives on Yucca Mountain, points out the Department of Energy, which makes storing the waste there a lot safer than sprinkling it across the countryside.

Of course, there are drawbacks to using Yucca Mountain for storage. Many advocacy groups are worried that it’s not safe to transport nuclear waste across 43 states, that the casks aren’t durable, and that because Yucca Mountain falls along several fault lines it could prove an unstable storage place. “The idea of geologic disposal is that the waste is supposed to stay put,” says Steve Frishman of the Nevada Agency for Nuclear Projects. Frishman advocates above-ground dry cask storage instead, saying that it would provide a reasonable level of safety until the U.S. can figure out how to properly dispose of the waste. Burnell agrees, saying that “dry cask storage is considered safe and acceptable today, and the question of whether Yucca Moutain is safe and acceptable hasn’t been answered.” 

But since dry cask storage is temporary, the government will have to act eventually. The only silver lining in this nuclear mess is that constant bickering over Yucca may have prompted the government to consider whether a different path altogether should be considered—one that could involve recycling nuclear waste, says Burnell. For now, the government seems intent on practicing its infamous “wait and see” method.

- Jessica A. Knoblauch

Eco-inquiries, conundrums, snafus? Write to askplenty@plentymag.com.


Comments

Readers should know that the bright yellow drums shown are NOT the dry casks that the questioner inquired about. The dry cask containers are much more robust with metal inner containers and concrete on the outside, both for strength and shielding of the radiation.
Regarding the last comment of the response, there is consensus among the scientific community that if we reprocess (recycle as some call it) the used fuel, there is still a need for a repository such as Yucca.

The search for the perfect is the enemy of good enough.

It is important to remember that the material stored in the dry casks is a solid, high temperature ceramic encased in corrosion resistant metal tubes. There is NO danger of a leak.

Making sure that the containers remain intact is quite simple - they are pressurized with some helium gas. A pressure sensor on the containers will provide an alarm if there is any drop in pressure.

There are many people within the "nuclear" industry who are quite upset by the idea that we should accept the current situation. They were banking on winning contracts capturing some of the tens of billions of dollars associated with Yucca Mountain.

As my friend Ted Rockwell has been known to say - "The money would not disappear into a rat's hole; it would go into some rat's pocket."

Sure - some day we might have to go back and paint or repair the dry casks. Why worry about that now, especially since we should be recycling the fuel long before the casks begin to show their age.

Both BMused and Rod are correct and I wish to add my opinion that the use of the 55 Gallon drum photo is very misleading when the whole article is about Dry cask storage that are very different from 55 Gallon drums
Two additional points:
A. Shipping of the dry casks is to be done in crash tested containers on rail cars that have shipped nuclear weapons in similar containers for dozens of years without a single incidence of a rupture or release of any hazardous material. This if far safer than the alternative of shipping them on our highways
B. Yucca Mountain has not been selected and tested arbitrairly. It has been thoroughly researched and compared with dozens of other sites in the USA and found to be the most geologically stable and secureable and safely distant from populated areas. Over 10 years of drilling tunnels, testing waste samples, rock analysis, geological history of the area, water seepage and dozens of other parameters the application to the DOE to open the Yucca Mountain site and complete it for High Level, RETREIVABLE, Nuclear waste storage was submitted in June 2008. The evidence is overwhelming that this is by far the best location and plan available in the USA and needs to be accepted and completed.
Retreivable is a key word in the Yucca Mountain design, because it assures that if and when we decide to recycle the spent fuel to recover the 80% of Uranium that is still useable we will be able to retreive the casks with out risk and any significant cost.

John:

What you say about the work done so far on Yucca is true, but it addresses the wrong question. There is no pressing need to move the material.

What is wrong with saving $30-$100 billion by simply putting the material into dry storage containers and leaving it where it is? Any good economist can tell you that it is good to defer costs into the future, especially when it is likely that the final activity will be easier then.

There is no safety risk - no one has been hurt and no one will be hurt by exposure to fission by-products because we understand how to handle it. Use some shielding, put a little distance between the material and people, and reduce the time when people have to be very close to unshielded material.

The stuff does not take up much space at the originating site. For those very few sites where there is no longer a reactor operating, move the material to a site where there is a reactor or where the government is already managing material.

Take the waste fund and give it back to the organizations who generated the used material to pay for the costs. Allow them to keep the future funds. Let them maintain responsibility for the material, but also let them recover the value that the material contains.

Moving the material as many rail miles as possible from its current location simply adds tremendous cost and confuses the public by making them think there is a big waste problem.