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Who’s afraid of nuclear waste?: WIPPing transuranics into shape

The views expressed are those of the author and are not necessarily those of Scientific American.


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Waste arriving at the WIPP from all over the country's non-commercial nuclear reactor sites (Image: PBS Nova)

About 50 miles from the Texas border in southeastern New Mexico sits the town of Carlsbad, home of the renowned Carlsbad Caverns. Its lesser-known claim to fame which actually might have a disproportionately long-lasting impact on the future of energy and the human species is as a site for the Department of Energy’s Waste Isolation Pilot Plant (WIPP), the only official waste repository in the US currently accepting high-level nuclear waste. Jessica Morrison from PBS has an excellent article on the workings of the WIPP and its importance for nuclear power (hat tip: Bora). With the disaster of Yucca Mountain still beckoning in people’s memory, the WIPP offers a welcome and unique possibility for the future:

The Waste Isolation Pilot Plant, known locally as WIPP (pronounced “whip”), opened in 1999 after decades of back and forth between state and federal regulators. Today, it holds more than 85,000 cubic meters of radioactive waste arriving from as far away as South Carolina. Currently, WIPP is only authorized to handle waste containing elements with atomic numbers higher than 92—primarily plutonium—that originated from the development and manufacture of nuclear weapons. Between 1944 and 1988, the U.S. produced about 100 metric tons of plutonium, most of which was used to develop nuclear weapons.

What I find pleasing on a deep level about the WIPP is that it relies on entirely natural mechanisms for sequestering the waste from the outside world. The basic principle is to dig a hole deep into a salt bed. Salt has the unique property of displaying “creep”, the tendency to flow into and around cracks and naturally form seals; seals that can be as tight as those formed by the hardest rock when they are laboring under pressures operating at 2100 ft underground. When you bury waste in salt, you are basically letting geology do its job and create a seamless tomb for the waste.

WIPP’s operators stack waste containers in rooms dug into the salt formation and then let geology do the rest. Under pressure from the ground above, salt formations flow into cracks and open spaces. Over several dozen years, salt will settle around the containers, forming a rocky seal. That self-sealing ability also protects the site from cracks caused by earthquakes—any that open will quickly close. So far, the site has been successful in containing radiation from the waste.

Working in WIPP is therefore a job with a time stamp; in some sense the mine itself is urging the workers to do their job quickly and get out the hell out of there, so that the earth can close around the waste and clasp it in its tight embrace.

WIPP feels like it’s in constant motion—the continuous care needed to control the salt, the movement of the electric carts within the mine’s pathways, the loading of waste first into the walls and then the room, back to front. It all serves as a reminder that the place really is moving, just at a slower, inexorable pace. WIPP depends “on salt and the behavior of salt,” Elkins says. Salt flows under pressure, and it’s under a great deal of pressure this far underground. On a geologic time scale, it presses down with surprising speed, crushing and then encapsulating whatever is placed inside.

What this also partly means is that the sooner the repository fills up with waste, the better it would be to close it and let the salt do its job. This is a good incentive for carting high-level waste from the nation’s myriad nuclear sites to WIPP as soon as possible. It’s not as if there is a shortage of waste waiting to be disposed:

While WIPP has been accepting nuclear waste from weapons programs, no central repository currently exists in the U.S. for spent nuclear fuel and related waste from commercial reactors. Until one opens, waste has been sitting in interim storage at or near each of the nation’s 65 nuclear power plants. At the end of 2011, these sites and others held more than 67,000 metric tons of spent nuclear fuel, according to a report issued by the Congressional Research Service.

Waste buried deep underground in the right kind of geological formation is extremely safe and many people who criticize the problem of nuclear waste don’t realize that good technical solutions based on burying waste have already been at hand for decades; the problem is mainly a political one. It’s worth appreciating the basic fact that there are two kinds of waste, short-lived intensely radioactive and long-lived mildly radioactive. The inverse relationship is a basic law of physics and plays to our advantage. Thus, short-lived isotopes like strontium-90 and cesium-137 might be biologically dangerous, but they also reach safe levels rather quickly (half-life about 30 years for both). On the other hand, long-lived isotopes like plutonium-239 (half-life 24,000 years) are less dangerous because of their lower activity. Typically nuclear waste contains both kinds of elements, and one of the bad decisions taken by the government in this country based on rather flimsy grounds was to halt reprocessing, a process that would have separated plutonium and other valuable and proliferation-prone elements from the short-lived waste and which is routinely done in Europe, Russia and Japan. Burying plutonium is thus both an unnecessary invitation to potential proliferation as well as a waste of valuable fuel for civilian nuclear reactors.

It’s hard to think of proliferation though when the plutonium is lying 2100 ft below ground covered by salt and earth as hard as kryptonite. Even when Yucca mountain was being discussed in the 70s and 80s, there were sound techniques for enclosing waste in borosilicate glass surrounded by layers of tamper-proof materials like copper and clay. The following illustration from a 1991 article on nuclear power by physicist Hans Bethe displays the multiple barriers separating transuranic waste from the environment:

Multilayered cylindrical design for the isolation of transuranic waste (Image: Engineering and Science, 1991)

When this kind of waste burial was being discussed, one of the cogent problems was that of groundwater seepage which might potentially transport the waste over great distances. But this problem is not as serious as it sounds at all. To begin with, waste repositories are already located away from both residential areas and groundwater sources. But even if groundwater were to come in contact with the waste, it would be several hundred thousand years before it ever reached the surface. As Bethe clarifies it in the same article:

“Groundwater doesn’t flow like a river; it creeps. At a disposal site in Nevada called Yucca Mountain the Department of Energy has measured the flow of groundwater at 1 millimeter per day. And it has to  flow a distance of about 50 kilometers before it comes to the surface, because it generally flows horizontally. With this alone, it takes more than 100,000 years (italics mine) to come to the surface. In addition to that, at Yucca Mountain the waste can be placed about 400 meters below ground, and the groundwater is 600 meters below ground, so the waste won’t even touch it. This might change due to  geological upheavals, but to start with it’s a very good disposal site.

And even if  the groundwater is flowing 1 millimeter per day, experiments have shown that most dissolved elements take 100 times longer to  flow than groundwater; they are constantly adsorbed by the surrounding rock and then put back into solution again. And plutonium, which is the element people are so afraid of, takes 10,000 times longer again to migrate than most elements. In other words, during plutonium’s half-life of 20,000 years, you are insured 100,000 times over.”

Yucca Mountain is now abandoned, but these general principles of waste storage still stand and plutonium can still be considered to be confidently isolated from the environment over multiple half lives when buried this way. With short-lived elements the solution is easier. It’s a pity that political inaction and public opinion has not allowed us to cart most of existing waste to sites like the WIPP. The waste is relatively small in amount to begin with – the annual waste from the 100 odd reactors in the US would only fill a football field to a depth of one foot – and storing it around creates unnecessary safety issues. Dry cask storage is a good solution but since the casks are often stored on land is far from a permanent one.

The public, government officials and experts should take the lessons of the WIPP and of existing techniques for disposing waste to heart. As with many things nuclear, one of the major problems is that of education; many members of the public think that all nuclear waste is alike, that all of it will kill you even on slight exposure, and that there is no way at all of disposing it. Stories like that of the WIPP should hopefully change their minds and demonstrate that the problem of nuclear waste is not a technical problem, it is one of psychology and politics.

Note: As Twitter user @AtomikRabbit pointed out to me, WIPP is only a repository for non-commerical nuclear reactors. It’s waste from such sources that’s displayed in the photo above.

Ashutosh Jogalekar About the Author: Ashutosh (Ash) Jogalekar is a chemist interested in the history and philosophy of science. He considers science to be a seamless and all-encompassing part of the human experience. Follow on Twitter @curiouswavefn.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Carlyle 4:05 pm 08/27/2013

    Excellent article. Thanks also to 9. rkipling 12:49 am 08/23/2013 for alerting me to your site. Again you are not listed under the main headings.

    Link to this
  2. 2. curiouswavefunction 4:40 pm 08/27/2013

    It’s ok, not all posts appear under the main headings; the editors pick the ones they want to highlight.

    Link to this
  3. 3. Carlyle 5:18 pm 08/27/2013

    Exactly.

    Link to this
  4. 4. John Tritium 6:52 pm 08/27/2013

    First, a correction. WIPP accepts Defense-generated transuranic nuclear waste (or TRU waste). The rest of the world refers to this dangerous material as “intermediate level” nuclear waste. This material is much more radioactive than low-level waste and does not emit the thermal heat, and in some cases, the higher radiation, that high-level waste does.

    THe decision to put high-level waste in yucca and intermediate stuff in WIPP was politically driven. Ask Nevadans outside of the rural NYE and Esmerelda counties (which would have received an economic benefit from YMP), they will call that legislation the “Screw Nevada Law.” The science actually pointed to WIPP for permanent disposal of both media.

    Make no mistake, WIPP was designed and built as a high-level nuclear waste repository. It has rail access and has a fully functional hot cell within its desert complex. The National Academy of Sciences have stated since the 1950′s that a salt repository, like WIPP, is the best place to entomb high level nuclear waste- not the leaky volcanic tuff that Yucca Mtn. sits in.

    Science and Economics are working together with politics to keep Yucca Mountain from ever opening. You’ve heard about the $15 Billion already spent on Yucca right? Have you heard that since Yucca is in a leaky geologic formation, it will take an engineered barrier or drip shield to seal off Yucca for the million years required by the NRC permit? Wanna guess what a large portion of this shield is supposed to be composed of (according to the DOE own design)? Titanium. Yep. This stuff we put in all of our aircraft, missles, etc. This and a few rare metals will cost a bundle, that is if you can convince the Air Force and say, the nation of China, to give up all its titanium for the forseeable future. Current estimates are that the Yucca drip shields would require approximately 33% of the world’s titanium supplies. To be blunt it will take another $16-18 billion to complete construction of the facility to meet the permit/design requirements. Where is Congressman Upton and Shimkaus on this minor expenditure. Talk about throwing good money after bad.

    Carlsbad wants to bring in high level waste now that WIPP has cleaned up a majority of the TRU waste across the nation and it still has a significant amount of volume left in which it could use for high level waste. Salt is much cheaper and easier to mine and it does not need a titanium drip shield as the thick bedded salt around Carlsbad is impermeable, incredibly stabile or geologic time, and remote. The community understands and it very supportive of this expanded mission and would do a great service for the nation.

    Link to this
  5. 5. sault 7:10 pm 08/27/2013

    Another problem with many things nuclear is cost. WIPP’s price tag is $19B. If you want a similar repository for civilian nuclear power waste, which I’m guessing is around 10x larger than the waste flowing to WIPP, then you would need to put down around $200B. And yes, the political hurdles would be tremendous since it would cause huge NIMBY blowback from the community chosen to host it just like Yucca Mountain did and all the communities where nuclear waste trains or trucks would be passing through on regular intervals would become very uneasy as well.

    BTW, at $2 per Watt, that $200B could by 100GW of wind power, which is roughly the generating capacity of the USA’s nuclear power plants. Since utilities are signing long-term power purchase agreements with wind farms for 4 cents per kWh, and the “Merit Order Effect” reduces wholesale power prices as more wind and solar are put on the grid, wouldn’t renewables be a better deal? Even ignoring the gargantuan price tags on nuclear reactors and their uncertain financial performance due to long build times and schedule delays, even just the waste repository they need could finance a lot of clean energy instead.

    Link to this
  6. 6. sault 7:16 pm 08/27/2013

    John,

    Estimates to complete Yucca Mountain run about $90B, but they probably don’t contain the titanium drip shield:

    http://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_repository#The_facility

    But once you get into the 100′s of billion$$$, who’s counting, right?

    Link to this
  7. 7. curiouswavefunction 8:13 pm 08/27/2013

    Housekeeping note: Thanks for your comments, the bit about titanium is really interesting. However, commenters are asked to condense multiple comments into one and try to keep individual comments brief; this will foster constructive discussion without making it appear like a small number of commenters are swamping the comments section (sault: for instance, that last comment of yours could easily have been subsumed into the previous one).

    Link to this
  8. 8. rkipling 8:42 pm 08/27/2013

    I have a feeling the word may get out about your blog on the other energy blog comments.

    Link to this
  9. 9. rkipling 9:09 pm 08/27/2013

    “The Midnight Skulker” strikes again! (With apologies to Johnny Hart & B.C.)

    Link to this
  10. 10. sault 10:28 pm 08/27/2013

    Ash,

    Apologies, but I started writing my first comment before John posted his, so I didn’t see it. After I posted my first comment, I saw John’s and then responded to it.

    Link to this
  11. 11. sethdayal 10:46 pm 08/27/2013

    The NRC, which is without a doubt a large millstone around the neck of nuclear power, still assigns a cost of .1 cents a kwh based on the latest waste disposal technology. The amount of waste is tiny – a football field covered a few meters deep. After a few hundred years the waste is deadly only if you eat it. Any leakage from Yucca after that would be insignificant relative to drainage from some high radiation tourist beaches in low cancer Brazil.

    In any case there is no point storing it long term as it is an excellent source of fuel for the Gen IV reactors – with two more going into service next year and many more by 2020.

    The cost of building wind plant is 15 cents a kwh as shown by the latest large farm build at Shepherd’s Flat – that with massive subsidy from Chinese dumping. Sault is utterly incapable of following the arithmetic despite numerous attempts.

    He states ” 100GW of wind power, which is roughly the generating capacity of the USA’s nuclear power plants” being unaware despite numerous attempts to demonstrate that wind has a capacity factor of only 25% or 25 GW average.

    Despite numerous requests Sault has been unable to provide a single link to a real wind farm whose unsubbed construction and operating costs are less than triple his 4 cents a kwh claim. Numerous times it has failed to penetrate his thickness that 4 cent a kwh price for wind contracts are subsidy included and a result of utilities scrambling to meet state renewable energy standards.

    The actual cost of first of a kind nukes in the US is 7 cents a kwh , 4 cents in the US and 3 cents in Asia if built by public power. The last 3 Japanese ABWR’s were built in 3 years, and the last 7 Candu’s in 4, similar to the 3 years it took to build that latest large wind farm at Shepherds Flat.

    No matter how many times Sault is contradicted he will continue to repeat the same talking points over and over frequently taking up as much as 75% of the comment thread. Why this is allowed on this site, I can only guess.

    Link to this
  12. 12. rkipling 11:31 pm 08/27/2013

    Well what do you know? They have you back on the Latest News and Energy topic. The Midnight Skulker’s work here is done.

    Link to this
  13. 13. sault 12:38 am 08/28/2013

    Seth,

    Utilities are signing long-term power purchase agreements with wind farms for 4 cents a kWh:

    “After topping out at nearly $70/MWh in 2009, the average levelized long-term price from wind PPAs signed in 2011/2012—many of which were for projects built in 2012—fell to around $40/MWh nationwide.”

    And integrating wind power only costs 0.5 cents per kWh, even if wind makes up over 40% of the power on the grid:

    “Recent studies show that wind energy integration costs are almost always below $12/MWh—and often below $5/MWh—for wind power capacity penetrations of up to or even exceeding 40% of the peak load of the system in which the wind power is delivered. The increase in balancing reserves with increased wind penetration is projected, in most cases, to be below 15% of the nameplate capacity of wind power and typically considerably less than this figure, particularly in studies that use intra-hour scheduling. Moreover, a number of strategies that can help to ease the integration of increasing amounts of wind energy—including the use of larger balancing areas, the use of wind forecasts, and intra-hour scheduling—are being implemented by grid operators across the United States.”

    http://emp.lbl.gov/sites/all/files/lbnl-6356e.pdf

    Now will you shut up with these lies about wind power being expensive? Or do you have a problem with reading comprehension?

    Link to this
  14. 14. sault 12:46 am 08/28/2013

    Oh and one more thing, sethy…

    New nuclear power plants are going to get the SAME production tax credit that wind farms are getting…on top of Price Anderson Act liability insurance coverage from the feds while they are also allowed to milk billion$$$ from their captive potential customers through “cost recovery” whether the nuclear reactor is actually finished or not.

    Sorry, but “Too Cheap to Meter” was really “Too slow and expensive to matter”…

    Link to this
  15. 15. Carlyle 1:44 am 08/28/2013

    Your slogans only impress the weak minded.

    Link to this
  16. 16. sethdayal 2:13 am 08/28/2013

    I’m sure Ash can see the enormous difficulty in dealing with the likes of Sault on this site. The only possible word to describe him is a troll.

    You will note he made a single post into two to expand his influence, after being warned about it. All these talking points, including the last two, all of them irrelevant to the topic, he’s repeated numerous times on numerous article threads. Whenever I get a chance I debunk them. It literally is impossible to keep since he is on site 24/7.

    I don’t know why Sault is utterly unable to read even his own links. Once again on the same page 4 cent a kwh contracts are a result of subsidy, the unsubbed cost starts at over 12 cents. Learn to read before posting!!!!

    Once again here you are quoting a study done for Big Oil’s Obama administration by the AWEA without peer review or publication in reputable journal. A 10 year old could easily predict disaster in a 40% wind regime when a front passes by and wind drops to zero with no backup.

    Here’s a peer reviewed study published in reputable journal that utterly contradicts this nonsense.

    “Wind energy is only able to replace traditional power stations to a limited extent. Their dependence on the prevailing wind conditions means that wind power has a limited load factor even when technically available…. Consequently, traditional power stations with capacities equal to 90% of the installed wind power capacity must be permanently online [and burning fuel] in order to guarantee power supply at all times”

    http://www.nerc.com/docs/pc/ivgtf/EON_Netz_Windreport2005_eng.pdf

    A study was performed of the performance of the 21 IWT facilities in Eastern Australian grid which is geographically, the largest, most widely dispersed, interconnected grid in the world.

    http://aefweb.info/data/Wind%20farming%20in%20SE%20Australia.pdf

    Not only does the entire fleet fail frequently, but also it fails throughout the year. Clearly, such performance would be unacceptable for any traditional method of generating electrical power.

    After analyzing the data, the authors stated wind energy cannot be used for base load, and that the installed capacity of required back-up must be at least 80% of IWT installed capacity.

    Since the nuke plant has a much longer life than renewables a small production subsidy is virtually meaningless. Without them no wind plant would be built.

    Cost recovery makes private power similar to public power – an excellent idea considering the inherent inefficiency of American private utilities. No wind/solar plant would every be built without subsidy. Perhaps the biggest wind/solar subsidy is the fact that nobody can sue them for liability for the all the folks murdered by the required gas backup.

    Link to this
  17. 17. John Tritium 2:33 am 08/28/2013

    My point is still the same. Capital cost of YMP’s completion far exceeds the cost of a salt repository such as WIPP. Operating cost is also far cheaper over the repository’s lifetime in a salt repository like WIPP compared to Yucca’s Lifetime cost (this is according to data gathered under President Bush’s administration by the DOE using actual data from WIPP and the estimates for YMP- Sault, you should do some reading of this report). Our national budget is literally in the outhouse and we really do need to let science and economic viability determine what is done with our nation’s nuclear waste and soon.

    One other point- YMP was to accept all of the nation’s high level waste under the NWPA [or the "Screw Nevada Law" as all of Nevada's leadership (both R's and D's) refer to the NWPA]. This includes used fuel rods, some of which (though not all) could conceivably be burned in the new fast burn reactors, if they ever go into production here. There is also a sizable amount of defense-created high level waste that cannot be used in any reactor designed today. This waste, which was left over from bomb-making, exists in various forms across the country. Some is even leaking into the environment. I’m sure Vegas is paying real close attention to the leaking tanks at Hanford. The states of Oregon and Washington would love to get this stuff in a safe location out of their environment. WIPP’s salt is the obvious answer for this high level waste (as the TRU waste repository there already takes a version of defense waste similar to it in many ways).

    I am amazed at the Lemming-like precision that Shimkus, Upton and many others in the House of Representatives exhibit in their illogical support of YMP. It is real difficult to understand why Upton, Shimkus, et. al. in the House of Representatives are fighting this when Nevada’s Republican Governor, Assembly, and Senator Dean Heller (R) have stated unilateral opposition to YMP in their state, and Republican Congressman Pearce from New Mexico and the Republican administration in Santa Fe, NM are willing to examine the scientific possibility of hosting a repository for this material in New Mexico. If the majority leadership in the house were smart, they would get together with these members of their party, offer a solution to the nation, and claim a true political victory.

    One more item that is ignored is the basic premise that there is already more HL waste out there right now than Yucca Mtn. could handle. Most experts agree that more than one repository is needed in this nation. Why not start looking for a second repository, say in salt, from a state and community that is willing to step up and start the process?

    BTW Sault…I’ve seen several figures on the actual costs and benefits of wind power (and solar) along with the tremendous cost of the transmission and storage infrastructure needed. It doesn’t remotely match your figures- (with our current technology at least).

    Link to this
  18. 18. Carlyle 3:50 am 08/28/2013

    Gratifying that the editors have decided to give your article headline status after all Ash. A pity they do not publish & promote more quality contributions.

    Link to this
  19. 19. SteveK9 9:13 am 08/28/2013

    Actually we don’t want to entomb spent fuel permanently. We will use it in the decades and centuries to come as a fuel source in deep-burn reactors. We might just as well leave it where it is, or perhaps collect the casks together at some regional sites, as has been suggested.

    Link to this
  20. 20. sault 11:19 am 08/28/2013

    John,

    As per the link I provided, The Department of Energy gathered data on power purchase agreements and determined that wind power came in at 4 cents per kWh and integration costs were 0.5 cents per kWh. This is old coal plant-levels of cheap.

    Keep in mind that renewables are a huge threat to dirty energy companies and the utilities that have literally trillion$$$ in infrastructure dependent on fossil fuels. They have a huge incentive to downplay the possibility of a sustainable energy future for as long as possible. A lot of the misinformation about wind, solar and other renewables comes from the fossil fuel companies themselves or is laundered through the think tanks they fund in order to give it a hint of legitimacy. Check to see who is behind the figures you’re looking at and you’ll be surprised!

    Link to this
  21. 21. Longhorn 78 7:53 pm 08/28/2013

    An astute observation of the mineral halite–salt. As the project manager for the DOE Strategic Petroleum Reserve (SPR) project, my staff leached huge caverns in salt domes in both Louisiana and Texas and emplaced over 60 million barrels of crude oil to be stored in case of a national emergency.
    It was during this period that I became obsessed with using these magnificent bodies of salt for other purposes. As a result, I bought a salt dome and used it to retain non-hazardous oil field waste. As the same time, I studied the feasibility of storing hazardous waste and even radioactive waste in the same salt formations. It is very feasible to use these massive formations as disposal vehicles as they are truly unique.
    As I explained in the May copy of EARTH magazine, the characteristics of salt make it an ideal medium to accept and retain wastes of varying types.
    My hat is off to the author of this excellent discussion of WIPP and the alternatives available.
    Scientists have proven the viability of salt as the potential host medium. Also, few know the fact that a 5KT nuclear device was detonated underground in a salt formation in Mississippi without creating any surface disturbance. Later examination of the site revealed a few minor fractures in the salt formation–most only a foot or so in length. Hence, the salt absorbed the entire energy expansion created by the nuclear explosion. That, alone, should speak volumes for using this valuable resource–salt.

    Link to this
  22. 22. evosburgh 11:41 pm 08/28/2013

    Here is another, and I think even more interesting, project that was run in the same general neighborhood:

    http://en.wikipedia.org/wiki/Project_GNOME

    Reportedly they are still detecting the residual radiation at the WIPP site.

    Link to this
  23. 23. Carlyle 5:10 am 08/29/2013

    RE: 21. Longhorn 78. Fascinating. It is imperative that thinking & informed people support those who shine a light through the murk of ignorance & agenda to expose the facts. We need more articles like this.

    Link to this
  24. 24. Gaythia 2:42 pm 08/29/2013

    I recommend reading more on the geology of the WIPP site. I think a good starting point, (picking something that is accessible online), is this publication by the New Mexico Geological Society: http://nmgs.nmt.edu/publications/guidebooks/downloads/44/44_p0331_p0338.pdf

    The driving force for adaptation of this site has been the political support by much of the local population. This is in sharp contrast to almost anyplace else. It should be noted that this area, despite it’s local promoters, was passed over in favor of Yucca Mountain previously.

    The second driving force is that it is true that this facility (or Yucca Mountain for that matter) are big improvements over current pool storage methods, once the hazards of transportation are accomplished. Dispersed dry cask storage works, short term, as long as we have the ability to monitor things. Our lack of progress with military related WWII waste, as at Hanford, amply demonstrates that this is not one of the things that humans are very capable of mustering the will to do on a long term basis.

    It is true that the salt does exhibit “creep”, fluid properties, that will enclose the waste. I think that members of the public visualize salt as a dry material, but this is not necessarily true. As the paper above notes, the containers of waste will get crushed and corroded in the corrosive briny environment. This could be extended somewhat by the use of better containers, but then we would be using up more valuable metals and expending more energy.

    The enclosure by salt creep will help somewhat in keeping the waste out of the reach of future wayward humans. Unfortunately it is also true that there is oil and gas in the immediate area, and also such mineral resources as potash.

    Groundwater aquifers occur in the formation below this layer. Layers above this contain aquifers that the paper here cites as “probably” discharging into the Pecos river. The salt layer itself contains pressurized brine reservoirs and some of these are associated with hydrogen sulfide gas. Test boreholes associated with planning the WIPP site did hit pressurized brine which did flow out onto the surface. While the facility was relocated as a result, there apparently are such brine reservoirs below it that could be hit by drilling through the facility.

    Note that the nearby Carlsbad Caverns were carved out by sulfuric acid: http://www.nps.gov/cave/naturescience/geologicformations.htm.

    Salt deposits can flow, and or dissolve and be re-evaporated and thus be removed entirely or relocate themselves and there is geologic evidence that some salt deposits in this area have done so. There is also the possibility of forming what is called a “Breccia Chimney” a solution subsidence structure that can form a pipelike conduit that might provide passage for the waste to the aquifer below.

    On much slower geologic time scales, material within the brine will migrate and gas present may also facilitate radionuclide spread.

    Link to this
  25. 25. Longhorn 78 3:25 pm 08/29/2013

    It is not my objective to demean or criticize those who attempt to rationalize the proper methodology for disposal of our radioactive waste, but it is bothersome to learn how few really understand the problem. At present, even with our advanced scientific knowledge, we place radioactive waste in barrels and stack the barrels in rows and often cover them with soil in a landfill. Have we reached a point in our society that we do not really care or appreciate the ultimate results of our careless ways? The scientific community has proven a method for disposal and that is in deep geologic structures, the prime one being salt. Placed in a salt formation, waste will remain for eternity–whatever that may be.
    We must consider that our life spans will dwindle and others will come after and dig up the ridiculous barrels of waste we have stockpiled. When they do, imagine what they will think of our stupidity.
    Placing the waste in salt as is being accomplished in the WIPP project makes sense. We need more sensible answers to a growing problem.
    At present, we have a nuclear facility in Japan leaking radioactive water into the Pacific Ocean. It won’t be long before that contaminated water reaches the U.S. West Coast. Of course the nuclear levels will be diminished because of the filtering effect of the ocean, but reach us it will.
    What are we doing about our nuclear facilities and ensuring they are not prone to the same fate?

    Link to this
  26. 26. Gaythia 4:50 pm 08/29/2013

    I have(in the distant past) worked as a chemist at Hanford and at Lawrence Livermore National Laboratory, where I was directly employed on projects involving groundwater management of radionuclide contaminants and ceramic based radionuclide sequestration and disposal. Although certainly not an “expert”, I do believe I have a professional level understanding of the hazards and risks we face. And as Longhorn 78 states, they are considerable.
    I note that Longhorn 78 mentions having experience in leaching out “huge caverns” in salt domes for use in oil storage. As I see it this means that the salt beds are not isolated from potential human intrusions. At the same time, the radionuclides enclosed within would not be truly contained in one place.
    I believe that we need to take steps now to decommission our most troubled aging reactors and to get spent fuel rods out of pools. I think that dry cask storage will be necessary short term. In my opinion the best long term storage option are deep within granite plutons of the Canadian shield. In my opinion, both WIPP and Yucca Mountain were largely political decisions. Carlsbad was clamoring for jobs. Nevada has long been used or misused as a big empty spot to do bomb tests, hide Area 51, or whatever. IMHO, the opposition by Nevada Senator Harry Reid was somewhat of a surprise to other federal level politicians.

    I think that if we were to look at nuclear energy on an energy unit based life cycle, from mining through building and then decommissioning nuclear plants, and on to reasonable guesstimates as to what long term repositories would “cost”, this does not make sense. I think that we can adjust such things as our energy usage patterns and passive storage methods to accommodate the intermittent nature of alternative energy. And I believe that there is much we can do to reduce consumption without negatively impacting either our lifestyle or our economy. In many ways a strong commitment to retooling for a new future could accelerate our society forward.

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  27. 27. Dr. Strangelove 3:26 am 08/30/2013

    67,000 tons of spent nuclear fuel. This will fit in one shipload and dump in the Mariana trench. Radiation cannot escape 35,000 ft of seawater. Radioactive materials will be diluted by the huge volume of Pacific ocean to safe level. Just warn James Cameron to wear radiation suit in his submarine.

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