Monday, April 15, 2013

High Level Waste Disposal

As the global nuclear industry continues to struggle with technical issues in its aging fleet, and the cost overruns and delays in new construction, a renewed focus has turned to decommissioning and more importantly the disposal of high-level wastes.  Germany just appointed a new commission to examine their waste disposal solutions, something the US did a few years ago, and they will probably come up with the same conclusions:  There is no real solution to the spent fuel problem!  But we have to do something…so what do we do?

There are several courses of action we (and this is true of all the nuclear nations) can take.  The consensus is to eventually bury the canisters in a deep geologic repository.  Easier said than done.  We have spent 30 years and close to $15 billion culminating with Yucca Mountain, which we have scientifically deemed unsuitable for a variety of technical problems, which of course the politicos have reduced to just “plain politics.”  The truth is that the waste is highly radioactive, which means it releases heat…we cannot predict what the impact of that heat and radiation will have on the geology and hydrology of the site, and on the actual casks containing the waste.  This material must be isolated from the environment for a minimum of 10,000 years.  Lots of uncertainty.  So what do we do?

Most of the spent fuel rods are currently stored on site in pools at the power plants.  They are slowly being encased in huge dry casks, and placed on guarded pad facilities.  This is costly and spreads the waste over 40-50 sites in the US.  But it may be the best option until a central underground repository is built (if it ever is.) 

Another possibility is to move all these casks (they are about 20 ft tall, 8 ft wide, and can weigh up to 150 tons each) to a central retrievable location, where they will sit until a repository is open.  One such site is Skull Mountain on Native American reservation land in Utah.  Although this would relieve the utilities from responsibility of maintaining the casks, it would concentrate an enormous amount of highly radioactive material in one vulnerable place.  Current estimates of the wastes we would produce if we were to build no new reactors would fill some 6000 casks.  Handling and shipping this number of casks, storing them in one concentrated location, and maintaining them from weathering, corrosion, and most importantly from possible terrorist attack would not be easy or cheap.  The current casks are designed for a life 50-100 years, so they would have to be re-casked and moved again to a repository if it is built.  Lots of uncertainty!

Another option is the recycle/reprocessing route.  Although this sounds idealistic, it really not a solution, and would create an even bigger mess than we have now.  Best described by Edwin Lyman: “Reprocessing is the worst possible alternative to deep geological disposal because it greatly increases the cost, as well as the dangers, of waste management. Reprocessing increases the total volume of nuclear waste sevenfold over direct disposal; those multiple new waste streams present additional challenges for storage, transport and disposal. Even worse, reprocessing produces copious quantities of concentrated nuclear-weapon-usable materials, primarily plutonium. One large reprocessing plant can produce about 1,000 bombs' worth of plutonium each year. 
Adding insult to injury, this technological disaster costs a lot of money.”  Reprocessing has been a nightmare for England, France, and Russia, and even Ronald Reagan recognized this when he cancelled reprocessing in the US.

So, as the Nuclear Waste “Blue Ribbon Commission” reported a few years ago, “No currently available or reasonably foreseeable reactor and fuel cycle technology developments - including advances in reprocess and recycle technologies - have the potential to fundamentally alter the waste management challenge this nation confronts over at least the next several decades, if not longer."  We all just wind up kicking the can down the road.

A few references to the above:
Three “experts” opinions

I’m just about finished going through “Uncertainty Underground” edited by Allison MacFarland, the new head of the Nuclear Regulatory Commission.  Everything and more that you want to know about nuclear waste, geology, hydrology, thermohydrology, volcanism, colloidal transport…whew!  Articles written by the very well qualified scientists who studied Yucca Mountain, and come up with the conclusion: UNCERTAINTY!

Cheap nuclear electricity!

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