Recycle Radioactive Material?

[Arctic Fox]

Is there any way to recycle nuclear waste or to stop its radioactivity/emissions besides burying it like a dog?

Re: My Hometown (http://www.russiajournal.com/news/cnews-article.shtml?nd=41147)

[selfAdjoint]

The Integral Fast Reactor (IFR) design can consume high rad waste and put out low rad waste. The low rad waste is not only less radioactive, but its half life is only decades instead of thousands of years.

[motai]

Is there any way to recycle nuclear waste or to stop its radioactivity/emissions besides burying it like a dog?

Spent nuclear fuel is refined and reprocessed in European countries, but it is not done in the United States (reenrichment of uranium is generally left to the military and may cause concerns over bomb production). Since spent nuclear fuel is still roughly 95% Uranium-238, the waste shouldnt need to be stored down in the ground forever.

http://web.em.doe.gov/tie/yucca1.html

[mee]

Spent nuclear fuel is refined and reprocessed in European countries, but it is not done in the United States (reenrichment of uranium is generally left to the military and may cause concerns over bomb production). Since spent nuclear fuel is still roughly 95% Uranium-238, the waste shouldnt need to be stored down in the ground forever.

http://web.em.doe.gov/tie/yucca1.html

I have heard that the temperature in Yucca Mountain, when full of waste, will be quite high. What is the reason we can't use this waste to fuel steam turbines for a long time?

[Orion1]

My understanding is that all nuclear waste is recyclable, such examples are nuclear batteries, reprocessed spent fuel rods, etc.

However, I believe the United States motivation is based upon the laws of economics. It is cheaper to re-mine Uranium than to reprocess spent fuel rods. If someday it becomes cheaper to reprocess spent fuel rods than re-mine Uraniun, the prospects of recycling the United States spent nuclear stockpile may become more economically appealing.

Perhaps its just a matter of advancing nuclear recycling technology to make such prospects more economically feasable.

I would personally like to see spent nuclear fuel waste reprocessed into giant nuclear batteries for some large industrial nuclear battery power plants. If only federalistic scientists were as objective as I am...

[hitssquad]

I have heard that the temperature in Yucca Mountain, when full of waste, will be quite high. What is the reason we can't use this waste to fuel steam turbines for a long time?Carnot's law (http://en.wikipedia.org/wiki/Carnot_heat_engine). The hotter the core temperature of a heat engine, absolutely relative to the coolant temperature, the more efficient it is. A heat engine (such as a turbine, which would be a poor choice for a low-temperature heat source) running off of the decay heat of spent reactor fuel would be too inefficient to produce electricity economically.

However, some industrial processes demand low enough temperature that their heat can be economically supplied by the decay heat of spent fuel rods. China recently announced plans (http://www.google.com/search?q=desalination+china+nuclear) to use spent nuclear reactor fuel to provide process heat for desalination plants. Though it might conceivably be feasible to use just the decay heat, China actually plans to re-use the spent fuel rods in a low-heat reactor to provide the heat for the desalination processes. If you are wondering why China wouldn't just continue using the same rods in the power reactors, the answer is that in their spent conditions the rods cannot produce enough heat to run the far more expensive power reactors (and it help to understand here that power reactors (nuclear reactors hooked up to turbines and dynamos) are much more complicated and therefore expensive than reactors that simply heat water (such as university research reactors and reactors solely providing industrial process heat).

Because of the massive investment that is tied up in a power reactor, it has to be run at nearly maximum power nearly all of the time in order to produce a positive return on that investment. That is one reason why fuel rods that still have plenty of burnable fuel in them are removed from power reactors after only ~4 years of service.

[mee]

My understanding is that all nuclear waste is recyclable, such examples are nuclear batteries, reprocessed spent fuel rods, etc.

However, I believe the United States motivation is based upon the laws of economics. It is cheaper to re-mine Uranium than to reprocess spent fuel rods. If someday it becomes cheaper to reprocess spent fuel rods than re-mine Uraniun, the prospects of recycling the United States spent nuclear stockpile may become more economically appealing.

Perhaps its just a matter of advancing nuclear recycling technology to make such prospects more economically feasable.

I would personally like to see spent nuclear fuel waste reprocessed into giant nuclear batteries for some large industrial nuclear battery power plants. If only federalistic scientists were as objective as I am...




Anyone know if the mining of uranium is now safer than it was in the past when all of the native americans became ill from working in them?

[runningthinker]

Spent nuclear fuel is refined and reprocessed in European countries, but it is not done in the United States

It is to my understanding that according to the Strategic Arms Limitation Talks (SALT) that the US is not allowed to recycle the fuel, as it is considered stockpiling nuclear arms.

I may be wrong about this but got my information from a recruiter that works for navy.

Can anyone confirm this?

[hitssquad]

It is to my understanding that according to the Strategic Arms Limitation Talks (SALT) that the US is not allowed to recycle the fuel, as it is considered stockpiling nuclear arms.Implicitly according to Richard Garwin, the reprocessing ban does not have anything to do with the SALT treaties.


The Weapons Connection

Following the lead of his predecessor, Gerald Ford, President Jimmy Carter in 1977 issued a directive forbidding reprocessing of civilian power reactor fuel in the United States and attempting to lead other nations to the same goal, primarily to avoid the contribution that separated plutonium could make to proliferation of nuclear weapons. At the time, it was clear that direct disposal of spent fuel was less costly than reprocessing fuel and recycling the plutonium and uranium. Nevertheless, the costs of the two methods are still being disputed by their partisans. A 1994 study of the Nuclear Energy Agency of the Organization for Economic Cooperation and Development claims no significant difference between the two options, but the study uses for direct disposal the very high cost per unit of spent fuel estimated for the small Swedish program, rather than those for the massive U.S. activity. Nevertheless, it estimates the reprocessing and recycling approach to be about o.o6 cent per kWh more costly than the direct disposal of spent fuel. This is a small fraction of the average price paid for electrical energy in the United States – some 6 cents per kWh – but that same report indicates that o.o1 cent per kWh is about $1 million per year per reactor. For the hundred or so reactors in the United States, o.o6 cent per kWh additional cost would total some $6oo million per year. Other estimates that involve the construction of new reprocessing facilities, such as the one being built at Rokkasho-Mura, Japan, result in much higher costs for reprocessing-some 0.5 cent per kWh....

If the American companies producing electricity today had to convert to reprocessing and bear the capital cost of construction of the necessary industrial complexes, they would be spending about o.65 cent more per kWh than the o.1 cent per kWh they pay today, to get rid of the spent fuel, which disposal is to be managed, not by themselves, but by the Department of Energy.14 With an average cost of electricity of some 5.9 cents per kWh (e.g., in 1997 8.5 cents/kWh for residential customers, 7.6 for commercial, and 4.6 for industrial), this would increase the cost of electricity by about 9%, and it would not ease significantly the problem of disposal of nuclear waste.(Richard Garwin & Georges Charpak. Megawatts and Megatons: A Turning Point in the Nuclear Age (http://www.amazon.com/exec/obidos/ASIN/0375403949/). pp144-145.)



Bernard Cohen also has detailed the 1977 Carter administration ban on reprocessing and he further also did not connect it with the SALT treaties. Bernard Cohen's most popular book on nuclear energy is published online here (http://www.phyast.pitt.edu/~blc/book/BOOK.html). In Chapter 13, he writes:


...the Carter Administration saw fit to go a step further. It decided to try to prevent the acquisition of reprocessing technology by nonnuclear weapons nations. As you may recall, reprocessing is a bottleneck that must be passed if nuclear power plants are to be used to make bomb materials; thus the goal of the government was, in principle, a desirable one. However, the method for implementing it was disastrous.

At that time (1977), Germany was completing a deal to set up a reprocessing plant in Brazil, Japan was building a plant, and France was negotiating the sale of plants to Pakistan and Korea. The Carter goal was to stop these activities through moral and political pressure. To set the moral tone for this effort — essentially to "show that our heart is in the right place" — he decided to defer indefinitely the reprocessing of commercial nuclear fuel in the United States.* This was the move that prevented the Barnwell plant from operating.

There were several problems with this approach. One was that the U.S. Government continued to do reprocessing in its military applications program, which was something of a dilution of the high moral tone being advertised....

But the worst problem with the Carter initiative was that it failed to achieve much in the way of results. The United States had enough political leverage over South Korea to force that country to cancel its purchase of a reprocessing plant. France cancelled its sale to Pakistan, probably in recognition of the fact that Pakistan had expressed ambitions for building nuclear weapons, but perhaps also partly as a result of American political pressure. However, the German deal with Brazil was not cancelled in spite of constant political pressure, including several face-to-face meetings between President Carter and German Chancellor Schmidt. The Japanese reprocessing plant was completed and started up. No other reprocessing activity anywhere in the world except in the United States was stopped by the Carter initiative.

[KaneOris]

Honestly, shoot it into space... yes people say we cant just send out litter into space.... WHY NOT?
BTW, yes i know its rather dangerous to send a rocket packed with nuclear waste into space. With all the rockets that blow up still! Its bound to send nuclear waste to the 4 corners of the world

[False Prophet]

Can we launch it into the sun? Otherwise it should be launched slowly enough that it will decay in time before it contaminates some alien ecosystem. Imagine if one day high-speed alien bio trash smashed into Earth, and 1 ppm of whatever it is was enough to cataclysmically change the environment. Maybe life on Earth was caused by intergalactic alien garbage?

[Chronos]

Yikes! :bugeye: Launching it period would be monumentally stupid. We can't even safely launch people into space. Can you imagine the consequences if the rocket exploded about 50 miles up in the atmosphere?

[Nereid]

Yikes! :bugeye: Launching it period would be monumentally stupid. We can't even safely launch people into space. Can you imagine the consequences if the rocket exploded about 50 miles up in the atmosphere?Or was inadvertently inserted into an orbit in which it came back to hit the Earth at >50 km/sec, or an orbit which the US early warning systems determined was a nuclear missile attack by a 'rogue nation', or ...

[hitssquad]

Can we launch it into the sun?According to the discussers of this on Know Nukes (http://groups.yahoo.com/group/know_nukes/), heavy metals launched at the sun would be reduced to atoms (but not destroyed) near the surface and then blown outward with the other particles that make up the solar wind. Like some of those other solar wind particles, some of the nuclear waste would end up trapped in Earth's ionosphere.

Another item of information gleaned from Know Nukes is that it takes more energy to launch things from the earth to the sun than it takes to launch things from the earth on a permanent trajectory out of the solar system.

[KaneOris]

Those who said that if it blew up in our atmosphere, it'd suck, i already mentioned that

[Chronos]

Those who said that if it blew up in our atmosphere, it'd suck, i already mentioned thatAgreed. I somehow missed your post.

[Morbius]

It is to my understanding that according to the Strategic Arms Limitation Talks (SALT) that the US is not allowed to recycle the fuel, as it is considered stockpiling nuclear arms.

I may be wrong about this but got my information from a recruiter that works for navy.

Can anyone confirm this?

I can "de-confirm" this.

The SALT Treaty does NOT limit the ability of the USA to reprocess fuel.

[ The Russians reprocess their fuel ].

SALT counts missiles - it doesn't address the warhead fuel issues.

No - the inability of the USA to reprocess nuclear waste is self-imposed
by an act of Congress in 1978 at the behest of President Carter as has
been discussed above.

The idea behind the 1978 law was to dissuade Great Britain, France, and
others from reprocessing nuclear waste - the USA leading by example.

It didn't work!! Great Britain reprocesses waste at Sellafield on the
Cumberland coast, and France reprocesses waste at LaHague - and
continue to do so.

In spite of the failure of the policy - the USA is still living with the
consequences of this action. It complicates the design and licensing
of our own disposal facilites [ ex. Yucca Mountain].

Unfortunately, there appears to be no movement to reverse a failed policy.

Dr. Gregory Greenman
Physicist LLNL

[Morbius]

The Integral Fast Reactor (IFR) design can consume high rad waste and put out low rad waste. The low rad waste is not only less radioactive, but its half life is only decades instead of thousands of years.

In the early part of my career in the early 1980s, I worked for
Argonne National Laboratory on the design of the IFR.

The IFR does recycle its waste - and it does so "in situ" - on site - so there
is no transport of fissile material outside the facility.

For more information, consult the transcript of a PBS Frontline
interview with my former boss, Dr. Charles Till at:

http://www.pbs.org/wgbh/pages/frontline/shows/reaction/interviews/till.html

Dr. Gregory Greenman
Physicist LLNL

[tumor]

EUREKA! Mt Saint Helen recently erupted, why not dump all nuclear waste into the volcano? N.waste will go down to the earth core and problem solved. :approve:

[theCandyman]

Problem solved! Now on to what to eat for dinner...

[Morbius]

EUREKA! Mt Saint Helen recently erupted, why not dump all nuclear waste into the volcano? N.waste will go down to the earth core and problem solved. :approve:

tumor,

Actually what you propose has been considered - but not with a volcano.

You don't want to put the waste into a volcano that might just spit it out
back at you.

However, in the ocean there are what are called "subduction zones" - it's
where one plate of the Earth is sliding under another. If you put the waste
in the plate that that is subducting - going under the other - then the waste
will be carried deep into the Earth - not to re-emerge until long, long after
the waste has decayed sufficiently.

Dr. Gregory Greenman
Physicist

[tumor]

Oh? I thought I will be laughing stock for proposing dumping radioactive waste into volacano, nice surprise.Thanks Morbius.

I know what you saying, we would have to find volcano which is in state of continious lava production but not explosive and main vent has to be straight something like Hawaiian volcanos.Mt Saint Hellen idea is a bad one. :redface:

[hitssquad]

what you propose has been considered - but not with a volcano.I know what you saying, we would have to find volcanoNo. He said, "...not with a volcano."



which is in state of continious lava production but not explosiveAll volcanoes are at least potentially explosive.

Here (http://www.google.com/search?q=%22subduction+zones%22+%22nuclear+waste%2 2) is some information on burial of nuclear waste in subduction zones.

[tumor]

Dumping down volcano main vent is still in my view better option than risking incredibly heavy subduction plates crush vessels with waste and dissipate radioactive materiall into the ocean.
If volcano main shaft is relativelly straight you dont have to worry about subduction plate crushing vessels with waste.

[Colby]

According to the discussers of this on Know Nukes (http://groups.yahoo.com/group/know_nukes/), heavy metals launched at the sun would be reduced to atoms (but not destroyed) near the surface and then blown outward with the other particles that make up the solar wind. Like some of those other solar wind particles, some of the nuclear waste would end up trapped in Earth's ionosphere.

Another item of information gleaned from Know Nukes is that it takes more energy to launch things from the earth to the sun than it takes to launch things from the earth on a permanent trajectory out of the solar system.

What if we launched it and sent it on a trajectory toward the Sun so that when the nuclear waste hits the Sun and is blown back out as solar wind that the Earth is on the other side of the Sun. I rather have dispersed nuclear waste hitting our atmosphere instead of a fuel rod crashing in my backyard. :surprised

[Morbius]

What if we launched it and sent it on a trajectory toward the Sun so that when the nuclear waste hits the Sun and is blown back out as solar wind that the Earth is on the other side of the Sun. I rather have dispersed nuclear waste hitting our atmosphere instead of a fuel rod crashing in my backyard. :surprised

Colby,

Why would you need the Earth on the other side of the Sun?

The Sun is a giant fusion reactor - our little bit of nuclear waste is
INSIGNIFICANT compared to the stream of high energy radiation
that the Sun throws at us from its own activities.

No - the reason one doesn't launch nuclear waste at the Sun is because
of the risk of launch failure. We've had several rockets and one Shuttle
blow up at launch or shortly thereafter.

Therefore, you would need to limit the amount of waste one had
aboard any single launch vehicle. That means a lot of launches - and
the cost of waste disposal becomes prohibitively expensive.

All that to solve what is really a non-problem - the risk of a fuel rod
crashing into your backyard - as you put it.

Nuclear waste will be transported in the strongest containers that
are made. These containers have been thoroughly tested by Sandia
National Laboratory:

http://www.sandia.gov/recordsmgmt/ctb1.html

Sandia put rockets on a diesel locomotive and rammed it at high
speed into a flatbed truck with the red fuel cask parked across the
tracks.

The result of the impact pictured was that the diesel locomotive LOST -
the only damage to the cask was purely cosmetic.

These casks have also been subject to intense fire - in pools of jet fuel:

http://www.sandia.gov/recordsmgmt/ctb1.html

I wouldn't worry about fuel rods crashing into my backyard if I were you.

Dr. Gregory Greenman
Physicist

[Colby]

Personally, I don't see the problem with storing the waste in Yucca Mountain in the first place. Launching it into space in the first place would be stupid. Like Dr. Greenman said, launch vehicle safety would be your main concern. If the waste can ever be contained safely enough to launch into space without worry of contamination, then it would certainly be safe enough to store in the middle of the desert.

[Morbius]

Personally, I don't see the problem with storing the waste in Yucca Mountain in the first place. Launching it into space in the first place would be stupid. Like Dr. Greenman said, launch vehicle safety would be your main concern. If the waste can ever be contained safely enough to launch into space without worry of contamination, then it would certainly be safe enough to store in the middle of the desert.

Colby,

Right On!!

Dr. Gregory Greenman
Physicist

[Astronuc]

At about $1000-$5000/kg, it is not economical to launch any waste into space.

Without reprocessing, it is best to just store it, presumably at Yucca Mt.

Reprocessing has its own problems - such as remote handling of the PuO2 and MOX, and fuel rods and assembly. That has made MOX fuel quite expensive.

[Morbius]

At about $1000-$5000/kg, it is not economical to launch any waste into space.

Without reprocessing, it is best to just store it, presumably at Yucca Mt.

Reprocessing has its own problems - such as remote handling of the PuO2 and MOX, and fuel rods and assembly. That has made MOX fuel quite expensive.

Actually NO.

Once the fission products are removed, PuO2 and MOX are relatively easy
to handle.

Plutonium has a half-life of 24,000 years. The degree of radioactivity
is inversely proportional to the half-life. So long half-life isotopes are
only slightly radioactive.

The U-235 in fresh fuel is even less radioactive - with a half-life of about
704 million years - doesn 't require any shielding at all.

Dr. Gregory Greenman
Physicist

[Astronuc]

Reprocessing has its own problems - such as remote handling of the PuO2 and MOX, and fuel rods and assembly. That has made MOX fuel quite expensive.

Actually Yes - From personal hands-on experience in the commercial industry, specifically in fuel manufacturing facilities in US and Europe.

I have handled UO2 (not ERU) fuel, but MOX (with Pu recycled from LWR spentfuel) fuel handling is done remotely. Please check Pu isotopic vector - Pu239, 240, 241 and 242 for LWR spentfuel. There are also trace amounts of Am-241.

Pu-240
Half life: 6564 years
Mode of decay: Alpha to U-236
Decay energy: 5.256 MeV
Mode of decay: SF
Branch ratio: 5.7E-6 %

Pu-241
Half life: 14.35 years
Mode of decay: Beta to Am-241
Decay energy: 0.021 MeV
Mode of decay: Alpha to U-237
Branch ratio: 0.0025 %
Decay energy: 5.140 MeV

Pu-242
Half life: 373300 years
Mode of decay: Alpha to U-238
Decay energy: 4.984 MeV
Mode of decay: SF
Branch ratio: 0.00055 %

Am-241
Half life: 432.2 years
Mode of decay: Alpha to Np-237
Decay energy: 5.638 MeV
SF negligible

Certainly WG MOX is more like to UO2.

[Arctic Fox]

Could you explain the "decay energy"?

I'm also trying to learn about RTGs and possible alternative fuels for it - Am-241 @ 5.638MeV > Pu-240 @ 5.256 MeV? :bugeye:

Isn't Am-241 inside smoke detectors? :eek:

And isnt Pu-240 weapons-grade material? :surprised

[hitssquad]

isnt Pu-240 weapons-grade material?None of the even-numbered Plutonium isotopes are preferred for weapons. Pu-239 is the typically preferred weapons isotope. "Weapons grade" refers to the amount of weapons-preferrable isotope present. In the case of plutonium, weapons-grade is generally considered 93% (http://www.google.com/search?q=pu-239+weapons+grade+%25) or better Pu-239.

[Morbius]

Could you explain the "decay energy"?

I'm also trying to learn about RTGs and possible alternative fuels for it - Am-241 @ 5.638MeV > Pu-240 @ 5.256 MeV? :bugeye:

Isn't Am-241 inside smoke detectors? :eek:

And isnt Pu-240 weapons-grade material? :surprised

Arctic Fox,

When an atom is radioactive, it has "extra" nuclear energy that it
gets rid of by emitting radiation in some form. That radiation could be
a gamma ray, an alpha particle, or a beta particle [ electron ]. The energy
that is released when the atom decays is the decay energy.

An RTG puts that energy to use. The radioactive material becomes hot,
and the heat is converted to electricity by thermocouples or some other
method.

The radiation source in smoke detectors is Americium-241

"Weapons grade" plutonium is plutonium that has a high concentration
of Pu-239. The weapons designer doesn't want Pu-240 or other even
numbered isotopes in the weapons fuel. These even numbered isotopes,
especially Pu-242 have a propensity to spontaneously fission which is
undesired.

Dr. Gregory Greenman
Physicist

[russ_watters]

One little thing to add: "Envrionmentalists" tend to cite half-life as a measure of radioactivity, which is (sorta) correct, except that they get it backwards. You usually see long half-life=bad. But when something has a long half-life, that means it is't giving off much radiation compared to something with a shorter half-life.

[Morbius]

One little thing to add: "Envrionmentalists" tend to cite half-life as a measure of radioactivity, which is (sorta) correct, except that they get it backwards. You usually see long half-life=bad. But when something has a long half-life, that means it is't giving off much radiation compared to something with a shorter half-life.

Russ,

Very good point!!!

For example, U-238 has a half-life of 4.47 BILLION years - about the age
of the Earth.

Since Depleted Uranium is mostly U-238; the so-called "evironmentalists"
have a field day with that long half-life.

However, as Russ points out - that long half life is precisely because it
has such a low decay rate - and hence a low level of radioactivity.

U-238 is "almost" stable.

To take it to the logical conclusion; Lead-208 has an INFINITE half-life;
because Lead-208 is stable.

Dr. Gregory Greenman
Physicist

[CharlesP]

So no one has a better suggestion than Yucca Mountain and Yucca Mountain is in hot water. This is one reason that Nuclear power is not considered the answer to the energy crisis. Let's summarize:
Send to sun - expensive unreliable
Drop in volcano - stuff comes out of volcanos (15000 psi)
Ocean trench - not trusted
Burn up in reactor - not effective
Use in batteries - health hazard
Use Yucca for heat - degrades containment

It doesn't matter how long the list gets, its all bad news.

[brewnog]

CharlesP, are you really serious?

Reprocessing!

[russ_watters]

So no one has a better suggestion than Yucca Mountain and Yucca Mountain is in hot water. This is one reason that Nuclear power is not considered the answer to the energy crisis. As already said a number of times, the problems with nuclear are entirely political. Both reprocessing and long-term storage are just fine scientifically.

[Astronuc]

Use Yucca for heat - degrades containment

What, pray tell, is the evidence to support this assertion?

In debate or classic rhetoric, it is customary to provide evidence in support of one's claim. In a technical matter such as this thread it would be appropriate to provide a calculation. What materials does one assume? What are the initial and boundary conditions of the thermal field? What degradation mechanism does one propose?

[CharlesP]

So no one has a better suggestion than Yucca Mountain and Yucca Mountain is in hot water. This is one reason that Nuclear power is not considered the answer to the energy crisis.
As already said a number of times, the problems with nuclear are entirely political. Both reprocessing and long-term storage are just fine scientifically.
That of course is an opinion which has been rejected by mainline scientists.
I saw in Physics Today that some study group determined that the Yucca project would not meet confinement time of 10,000 years and this is a big obstacle. I hope they solve their problems because this is the only hope for any long term confinement.
Reprocessing caused Rocky Flats which has caused many folk to decide that won't be permitted again.

[Astronuc]

In 10,000 years, most of the highly radioactive nuclides will have decayed to inert forms. Take two common isotopes Cs-137 (t1/2~ 30 yrs) and Sr-90 (t1/2~28.8 yrs). Cs-137 will experience 333 half-lives, and Sr-90 about 347 half-lives in 10,000 yrs. Their activities at that time will be exp(-333) and exp(-347) of the activity when placed in YM. Pretty small numbers.

The shorter half-life material will have even lower activity.

Radio nuclides with half-lives on the order of 100 years would have activities of exp(-100) - still a very small number.

But what about something with a half-life of say 1000 yrs. Well, it would decay to activities of exp(-10) = 4.5E-5. However, if one looks at the fission yields - the yields of long-lived isotopes are relatively low (say about 0.001 to 0.00001).

The concern then is the long-lived - low activity species with half-lives of 10,000 years or more.

But in 10,000 yrs, they will surrounded by inert material - metal oxides - which will probably have very low solubility.

But then the spent nuclear fuel is stored in corrosion resistant steel containers - or perhaps concrete - which is then surrounded by the rock of the mountain - which has been geologically stable for a few million years.

[CharlesP]

In 10,000 years, ...

But what about something with a half-life of say 1000 yrs. Well, it would decay to activities of exp(-10) = 4.5E-5. However, if one looks at the fission yields - the yields of long-lived isotopes are relatively low (say about 0.001 to 0.00001).

The concern then is the long-lived - low activity species with half-lives of 10,000 years or more.

But in 10,000 yrs, they will surrounded by inert material - metal oxides - which will probably have very low solubility.

But then the spent nuclear fuel is stored in corrosion resistant steel containers - or perhaps concrete - which is then surrounded by the rock of the mountain - which has been geologically stable for a few million years.
Steel and concrete have not passed stability tests for these time periods and the mountain and climate are both subject to unpredictable changes. Especially with humans doing everything suicidal imaginable.

[Morbius]

Steel and concrete have not passed stability tests for these time periods and the mountain and climate are both subject to unpredictable changes. Especially with humans doing everything suicidal imaginable.

Charles,

You have got to be the most ill-informed anti-nuclear propagandist
posting on this site.

Steel, concrete, and the volcanic tuff of the mountain have been extensively
studied, tested, and modeled:

http://www.llnl.gov/str/Glassley.html

The radioactivity of the waste will be much less than that of the ore
dug from the ground in a time period considerably less than any time
in which the containment might fail.

Dr. Gregory Greenman
Physicist

[russ_watters]

Playing devil's adovocate here (of a different sort), I think its an unreasonable constraint to expect any storage site to survive 10,000 years. Doing so assumes no further advances in nuclear technology will be made. Considering we've only known about nuclear power for 75 years or so, I think chances are pretty good the next hundred or thousand years of scientific discovery will reveal a way to deal with all that waste (dare I say - reprocessing!).

[brewnog]

Russ, faith in the future is indeed a wonderful thing!


In any case, I'm interested about this 'Rocky Flats' card which CharlesP seems to be playing a lot. Having seen reprocessing in action a number of times in the UK (and, I might add, reprocessing of waste originating from the US), I'd like to know more about the reasons it's currently outlawed. Morbius, you come across as reasonably well informed, (and also, much of what I've googled on the Rocky Flats issue seems to be horrific, unsubstantiated propaganda), - what happened?

[russ_watters]

HERE (http://www.cdphe.state.co.us/rf/historyofrf.htm) is some history of the site. Basically, they made nuclear weapons parts there (plutonium triggers) and they polluted a lot. I'm not real up on what the conspiracy theorists say about it though.

[Astronuc]

The Carter administration halted reprocessing out of concerns over the issue of 'proliferation' of Pu.

Economics in the US do not favor reprocessing at the moment - unless YM drags on - and back end costs start soaring. Europe, particularly France/Belgium, have entirely different fuel cycle economics. France and Belgium have a great deal of experience in reprocessing commercial spent fuel.

As for Rocky Flats - it was bad program management. Some folks thought that since they were in the weapons complex, they did not need to follow appropriate procedures or environmental regulations. This allowed for sloppiness.

The site provided by Russ_Watters pretty much describes the situation. It was unncessary. And it had nothing to do with technology - just bad (negligent and contemptible) decisions by those who were responsible for operating the plant. It is my experience that the vast majority of folks in the commercial nuclear industry do not behave in that manner.

[CharlesP]

The radioactivity of the waste will be much less than that of the ore dug from the ground in a time period considerably less than any time in which the containment might fail.
There is a study out which caused a stir in Congress which disagrees with that. I hope it is not a show stopper. We need mean quality men but Yucca is our only hope.
As for Rocky Flats - it was bad program management. Some folks thought that since they were in the weapons complex, they did not need to follow appropriate procedures or environmental regulations. This allowed for sloppiness....It is my experience that the vast majority of folks in the commercial nuclear industry do not behave in that manner.
That may be, but the present administration resembles the Rocky Flats managers, and with busted regulations the temptation may be too great. Once again we need "tough quality folk" and Three mile Island did not give me any confidence.
If the managers and bean counters could be locked out and engineers allowed to do their jobs, we might get a quality product- just what we need to keep us from freezing in the dark, just a few short years from now.
Rocky Flats is on prime land between Denver and Boulder. The area even outside the fence was so radioactive that some folks wanted to dig up the soil. Physics Today had a report on the waste tanks at Hanford that gave me the creeps. Of course today folks are much more careful.

[Morbius]

There is a study out which caused a stir in Congress which disagrees with that. I hope it is not a show stopper. We need mean quality men but Yucca is our only hope.

I don't know how some "study" can disagree with the Laws of Physics.

Nuclear waste does decay. The longest lived nuclear waste component
of any consequence is Cesium-137 which has a 30 year half-life.

So the radioactive decay of nuclear waste is bounded above by an
envelope with a 30 year half-life decay rate.

No study needed - it's just physics.



That may be, but the present administration resembles the Rocky Flats managers, and with busted regulations the temptation may be too great. Once again we need "tough quality folk" and Three mile Island did not give me any confidence.

Why do political prejudices always seem to dominate these discussions
of late? How nuclear power plants are run, and how engineers design
equipment is not dependent on the Administration in Washington.

President Bush and his minions are much too busy to be concerned about
how to run nuclear power plants.


If the managers and bean counters could be locked out and engineers allowed to do their jobs, we might get a quality product- just what we need to keep us from freezing in the dark, just a few short years from now.

When I was working toward my doctorate at M.I.T. - I attended a seminar
by the then president of the American Nuclear Society. He stated that
in the wake of TMI, scientists and engineers could tell the CEOs of
utilities that the nuclear power plant that they were running could
financially destroy their company if they don't run it correctly!

THAT gets their attention. Then he said the good news was "...we can
help you.." - the "we" being the engineers.

For the last quarter century - that IS the way it has been in the nuclear
industry. Utilities are extremely careful in the manner in which they
operate nuclear power plants.


Rocky Flats is on prime land between Denver and Boulder. The area even outside the fence was so radioactive that some folks wanted to dig up the soil. Physics Today had a report on the waste tanks at Hanford that gave me the creeps. Of course today folks are much more careful.

Rocky Flats was a weapons production plant. Rocky Flats took ingots
of Plutonium and fashioned them into the heart of a nuclear weapon.

How does that have anything to do with commercial nuclear power?

The operations conducted at Rocky Flats were not those that are done
in the commercial nuclear power industry.

The operator / contractor at Rocky Flats was Rockwell International -
the people that built the Space Shuttle. So Rocky Flats was managed
by a company that didn't have anything to do with nuclear power.

So how does the experience at Rocky Flats have anything to say with
regard to commercial nuclear power. It has virtually nothing in
common with commercial nuclear power.

Dr. Gregory Greenman
Physicist

[russ_watters]

When I was working toward my doctorate at M.I.T. - I attended a seminar
by the then president of the American Nuclear Society. He stated that
in the wake of TMI, scientists and engineers could tell the CEOs of
utilities that the nuclear power plant that they were running could
financially destroy their company if they don't run it correctly!

THAT gets their attention. Then he said the good news was "...we can
help you.." - the "we" being the engineers.

For the last quarter century - that IS the way it has been in the nuclear
industry. Utilities are extremely careful in the manner in which they
operate nuclear power plants. Slightly related/OT, but this reminds me of the Morton Thykol (sp?) Engineering Ethics case study. The management of that company overruled their engineers on an engineering decision which led directly to the destruction of the Space Shuttle Challenger.

The point is that managers seem to me to be equally arrogant/ignorant in dealing with engineers and engineering decisions: but only once. One error caused by not listening to engineers is enough to destroy a company or even an industry when the stakes are this high. TMI was that one error and I believe Morbius when he says 'the management' got the message.

[brewnog]

...but Yucca is our only hope.


So basically, that's untrue. Reprocessing, and storage elsewhere, are both perfectly viable solutions which are being constantly discredited. I now see that Rocky Flats is not even an example of a waste disposal plant, let alone an example of why reprocessing should not be carried out in the US!

If reprocessing was inherently as dangerous as is being made out, I doubt the States would be as happy to outsource nuclear waste reprocessing as they currently are.

[Morbius]

So basically, that's untrue. Reprocessing, and storage elsewhere, are both perfectly viable solutions which are being constantly discredited. I now see that Rocky Flats is not even an example of a waste disposal plant, let alone an example of why reprocessing should not be carried out in the US!

If reprocessing was inherently as dangerous as is being made out, I doubt the States would be as happy to outsource nuclear waste reprocessing as they currently are.

brewnog,

Reprocessing isn't being opposed because it is dangerous - but because of
the type of waste reduction it represents.

The bulk of the material discharged from a reactor is U-238. U-238
represents the bulk of the material that went into the reactor, and the
bulk of the material that comes out.

The 3-4% of the fresh fuel that was U-235 has been fissioned - and
replaced by radioactive fission products. A small amount of U-238 has
been transmuted to Pu-239 and either fissions or remains in the fuel.

However, the bulk of the spent fuel is represented by U-238 that is no
more radioactive than when it was dug out of the ground.

Reprocessing allows one to separate the U-238 from the radioactive
fission products and actinides. It's the fission products and actinides
that are the true "nuclear waste".

One can visualize the degree of waste reduction from the following.
If all the electricity for a family of 4 were generated by nuclear power
for 20 years - the waste generated would fit in a shoebox.

If one reprocesses that shoebox full of waste - one is left with an amount
of waste that fits in a common pill bottle.

That's the reason some are opposed to reprocessing - it greatly reduces
the volume of waste. Some don't want to reduce the amount of waste.
They also don't want to open a facility to store the waste. Their
objective is to totally stop the back end of the nuclear fuel cycle - to
stop any way of dealing with the waste. They want the spent fuel to
accumulate in the cooling pools at the reactors. If they can stop the
disposal of waste - and the pools fill up - then the utility can't operate
the reactor which will generate more waste. They will have succeeded
in their true objective - shutting down the nuclear power industry.

Dr. Gregory Greenman
Physicist

[Arctic Fox]

brewnog,
They want the spent fuel to accumulate in the cooling pools at the reactors.

Sheesh, contact me via email and I'll give them a location in Mexico they can drop it off for me... :surprised

:biggrin:

[brewnog]

Cheers for that Morbius, sorry, I wasn't implying that it was commonly being made out that it was dangerous, rather just that it seemed CharlesP was making it out as such.

But even with all that said, (esp. the bit about people being opposed to volume reduction), do you believe it *still* boils down to general public/political misconception?

[CharlesP]

Nuclear waste does decay. The longest lived nuclear waste component of any consequence is Cesium-137 which has a 30 year half-life.
So the radioactive decay of nuclear waste is bounded above by an
envelope with a 30 year half-life decay rate.
Using this as a starting point I did a rough calculation and came to the conclusion that a pill bottle of Cs137 will decay to about 600 atoms in 2100 years. (6x10E23 = 600x 10E21 = 600 x 2E70 --> 70x30 = 2100 years)
I think I could tolerate 600 radioactive atoms in my yard. That is a lot less than the cosmic ray background.
Then why does anyone care about containment longer than two thousand years?

[Astronuc]

Then why does anyone care about containment longer than two thousand years?

Because - some isotopes will moderate to long half-lives are still around, e.g.

Pu-239
Half life: 24,131 yr

Pu-240
Half life: 6564 years

Pu-242
Half life: 373,300 years

If particles of Pu-239 and 240 are inhaled into the lung or ingested into the body, there is a strong risk of cancer. There are those who are opposed to YM because they believe that something catastrophic will occur such that the Pu material will escape and find its way to populated areas where it will be absorbed in a favorable manner and cause cancer. Others believe that terrorists will sabotage a shipment of spent fuel on its way to YM, with the same results - dispersion of Pu and other fission products into the environment. However, shipping systems are designed to be secure and since they are massive, no one is going to grab and run off with a spent fuel container.

[Morbius]

Because - some isotopes will moderate to long half-lives are still around, e.g.

Pu-239
Half life: 24,131 yr

Pu-240
Half life: 6564 years

Pu-242
Half life: 373,300 years

If particles of Pu-239 and 240 are inhaled into the lung or ingested into the body, there is a strong risk of cancer. There are those who are opposed to YM because they believe that something catastrophic will occur such that the Pu material will escape and find its way to populated areas where it will be absorbed in a favorable manner and cause cancer. Others believe that terrorists will sabotage a shipment of spent fuel on its way to YM, with the same results - dispersion of Pu and other fission products into the environment. However, shipping systems are designed to be secure and since they are massive, no one is going to grab and run off with a spent fuel container.

Astronuc,

However, Pu-239, Pu-240, and Pu-242 are exactly the isotopes that will
be removed from the waste and recycled back to the reactor to be
fissioned if one reprocesses.

When one reprocesses nuclear waste, the Pu-239, Pu-240, and Pu-242
will no longer be in the waste stream that is buried.

That's another good reason to reprocess - it makes the disposal of
nuclear waste much, much easier! That's why countries other than the
USA, like Great Britain and France - reprocess their spent fuel.

It's a win-win situation; one gets additional "mileage" from the nuclear
fuel - by being able to get additional energy by fissioning the residual
Pu-239, Pu-240, and Pu-242 in spent fuel which will be separated out and
returned to the reactor as fuel. One eliminates the long lived isotopes
from the waste stream - so one doesn't need to worry about the long
lived isotopes - they are no longer in the waste stream.

Reprocessing just makes so much sense - which is why the obstructionist
anti-nuclear people got Congress to outlaw it in the USA back in 1978!

Dr. Gregory Greenman
Physicist

[Astronuc]

I agree that Pu-239, Pu-240, and Pu-242 are exactly the isotopes that will be removed from the waste stream and recycled if the US were to reprocess.

But the utilization of YM is for a once-through fuel cycle, which is where the US is today.

The point I was trying to make is that there are those opponents of YM who are afraid that these Pu isotopes will somehow leak out of YM and get into the environment. I happen to disagree with that scenario.

I would certainly be interested to see if someone in DOE or the commercial industry seriously considers reprocessing again.

[CharlesP]

One problem with reprocessing is that no chemical process is perfect. That means separation will be only approximate. There will be some of everything in each waste stream. That probably is not acceptable depending on the numbers which I don't have.

Then for more trouble - anyone remember Karen Silkwood? Wasn't a movie made about her?

[Morbius]

One problem with reprocessing is that no chemical process is perfect. That means separation will be only approximate. There will be some of everything in each waste stream. That probably is not acceptable depending on the numbers which I don't have.

Then for more trouble - anyone remember Karen Silkwood? Wasn't a movie made about her?

Charles,

Once again I have to disagree!

The chemical process that separates out Plutonium for example is a 19 step
process that switches the valence state that is being selected at each step.

In other words, the process is a 19 step gamut - and only Plutonium with
its unique set of valence states can successfully run that gamut. Thus it
makes for an extremely selective chemical process.

As for Karen Silkwood, she was a worker at the Kerr-McGee weapons
plant in Oklahoma where she prepared Plutonium fuel for the U.S.
Government's weapons production reactors.

She died in a single car accident in which she ran off the road. The
movie tried to imply that somehow she was murdered - but there has
never been any evidence of that.

One can read about the Karen Silkwood story at:

http://www.pbs.org/wgbh/pages/frontline/shows/reaction/interact/silkwood.html

Dr. Gregory Greenman
Physicist

[hitssquad]

One can read about the Karen Silkwood story at:

http://www.pbs.org/wgbh/pages/frontline/shows/reaction/interact/silkwood.htmlMaybe not. Compared against the investigative report published in the December 1979 and January 1980 issues of the Saturday Evening Post (Nick Thimmesch. "Karen Silkwood Without Tears.") the PBS summary seems incomplete and distorted.

[Morbius]

Maybe not. Compared against the investigative report published in the December 1979 and January 1980 issues of the Saturday Evening Post (Nick Thimmesch. "Karen Silkwood Without Tears.") the PBS summary seems incomplete and distorted.

hitssquad,

Perhaps you could enlighten us further?

A URL or a synopsis?

Dr. Gregory Greenman
Physicist

[Morbius]

Further information on the reasons for reprocessing:

http://www.pbs.org/wgbh/pages/frontline/shows/reaction/readings/rossin.html

Dr. Gregory Greenman
Physicist

[Arctic Fox]

Why not shove this stuff back from where we got it - in the original Uranium mines?

:confused:

[CharlesP]

How about all the other radioactive isotopes in a fuel rod. Doees each get a bunch of steps too? Which is first?

If uranium is not dangerous how come there is all this fuss about Uranium mine tailings?

[Astronuc]

In reprocessing the idea is to dissolve the fuel into some aqueous solution, e.g. nitric acid. In this solution, the desired elements (in this case isotopes of U and Pu) are selectively extracted into another solution (solvent extraction).

The U,Pu solution is then processed to remove the U and Pu which will ultimately become UO2 and PuO2 to be used in fuel again.

The other solution (the 'waste' stream) contains the undesirable fission products and perhaps transuranics which could also be extracted if the economics dictate. These can then be precipitated or absorbed preferentially on a filter, and removed from the solution. The aqueous solution can be recycled in a closed loop back to the nitric acid make up.

The precipitates of fission products in the form of oxides and hydroxides (and some other complexes) can then be dried and calcined (i.e. made into a ceramic or metal oxide). The ceramic is mixed with other (inert) glass/ceramics and vitrified into either a glass or synthetic mineral (e.g. Synroc). That material can be encapsulated in a corrosion resistant container and buried. This is pretty much the French method - burying the vitrified waste.

As with any mining operation, tailings are the spoils of the mining operation. They are more or less like sand or dirt. Rain may wash through the tailings and leach out other elements (heavy metals). In the case of uranium ore deposits, there are trace levels of decay products from the natural decay of uranium - including actinium, radium, radon, polonium, and a few other radionuclides, and lead, which is not radioactive, but is a heavy metal. Some of these elements can be found in coal deposits as well.

There are usually other elements like vanadium in some uranium ores such as carnotite and tyuyamunite. The vanadium is extracted in addition to the uranium.

[Morbius]

How about all the other radioactive isotopes in a fuel rod. Doees each get a bunch of steps too? Which is first?

If uranium is not dangerous how come there is all this fuss about Uranium mine tailings?

Charles,

As Astronuc points out - all the actinides can be separated from the
fission products.

The point about Uranium - is why should one demand that U-238 be be
sealed in borosilicate glass, then several layers of steel, and finally
buried in a repository - while all the time the anti-nukes are screaming
"bloody murder" - when U-238 exists in the ground naturally - and without
all the extra containment.

Dr. Gregory Greenman
Physicist

[CharlesP]

Whole areas of Colorado contaminated by mine tailings are considered unfit to live on. All of this is "natural" material.

[tumor]

Charles,

As Astronuc points out - all the actinides can be separated from the
fission products.

The point about Uranium - is why should one demand that U-238 be be
sealed in borosilicate glass, then several layers of steel, and finally
buried in a repository - while all the time the anti-nukes are screaming
"bloody murder" - when U-238 exists in the ground naturally - and without
all the extra containment.

Dr. Gregory Greenman
Physicist

Maybe because U-238 in nature is not as concentrated as in radioactive waste.

[Astronuc]

Spent fuel is mostly U238 in the form of UO2. In modern fuel cycles, the content of U235 varies between 4-5%, so 95-96% of U is U238.

During operation in a LWR core, two things happen with the U, 1) the U-235 fissions producing two fission products, and 2) U-238 absorbs neutrons to eventually produce Pu-239 (and other isotopes of Pu, Am, Cm, with the latter two being in low levels).

At discharge, modern fuel with have a burnup (energy produced/unit mass of U) of 50-60 GWd/tU. This is roughly equivalent to 5-6% of initial U consumed, which is now in the form of highly radioactive fission products. Also, part of the fissioning occurs in the Pu-239 that is produced by conversion of U-238, as Morbius pointed out elsewhere, and in high burnup fuel, as much as half the fissions are in Pu-239.

Mine tailings have 'natural' amounts of radioactive elements (related to the decay of U-235 and U-238), which are left after the U ore has been extracted.

Every mining operation (for copper, gold, silver, iron, lead, zinc, molybdenum, etc) leaves tailings which release heavy metals into the environment - so it is not just U mining that causes hazards, although due to their nature, U mine tailings would have higher level of radioactivity.

"According to the National Council on Radiation Protection and Measurements, sedimentary rocks such as shale and sandstone (quarts) contain about one (1) to four (4) micrograms of uranium per gram of rock. Beach sands contain about three (3) micrograms of uranium per gram of sand. And soil contains, on average, one (1) to three (3) micrograms of uranium per gram.

Igneous rocks, such as basalt, salic and granite, can contain from 0.5 to four (4) micrograms of uranium per gram of rock. However, there can be wide variations in this range in certain regions of the world. Because of the way these rocks were formed during the cooling of magma, light-colored igneous rocks tend to have the highest concentrations of radioactivity." from http://www.iem-inc.com/askq32r.html

So radioactivity is not unique to U-mine tailings, although there is somewhat higher levels than the examples just stated.

[Morbius]

Maybe because U-238 in nature is not as concentrated as in radioactive waste.

tumor,

As astronuc correctly points out - the concentration of U-238 in nuclear
waste is about 96% or so.

The concentration of U-238 in natural uranium is 99.3%

So the concentration of U-238 in natural uranium EXCEEDS the percentage
in spent fuel.

So much for your argument.

Dr. Gregory Greenman
Physicist

[CharlesP]

The US uses depleted uranium in some munitions because of its density. There has been quite a controversy about it.

Houses were built on ground contaminated with mine tailings in Colorado and I suspect those developments were abandoned.

There was a criticality accident in Japan a few years back in which at least one person was exposed or killed. The result has been resignation of at least one corporate officer and a public relations disaster for the Japanese nuclear industry.

The continued use of fuel rod cooling pools in the US has been a very undesirable development.

I was told by an ex Navy reactor man that there is no way to safely contain nuclear waste.

[hitssquad]

there is no way to safelyThis is a philosophy question and it belongs in the philosophy section of Physics Forums.

[Morbius]

I was told by an ex Navy reactor man that there is no way to safely contain nuclear waste.

Charles,

Then your ex Navy reactor man doesn't know what the hell he's talking
about.

The National Academies of Science and Engineering say that nuclear
waste can be safely contained. [ In fact it was the National Academy of
Science that first suggested a "Yucca Mountain" type repository back
in the late '50s.]


Scientists from our National Laboratories say nuclear waste can be
safely contained:

http://www.llnl.gov/str/Glassley.html

Nuclear waste storage has been very thoroughly studied.

Additionally, it's not like we have any option - nuclear waste exists!
We can't "unmake" it - it HAS to be stored somewhere!

Dr. Gregory Greenman
Physicist

[russ_watters]

I was told by an ex Navy reactor man that there is no way to safely contain nuclear waste. This is obviously false at face value: nuclear waste has been safely contained for 50 years.

[Nereid]

Wouldn't it be nice to have some natural reactors, with buried spent fuel and decay products, to study? Maybe then we could see how many harmful effects there are, through a perfectly natural experiment :smile: We could also calibrate ... you know, near this natural reactor, there seem to have been no increases in harmful effects due to radiation, over those of similar natural sites of enhanced radiation (e.g. certain basalts and granites), and way below such unnatural activities as flying thousands of hours in jets at 35k feet (or higher ... do the calculations on the increased exposure due to cosmic rays - or don't, if you don't want to get a big shock).

Ah, but there aren't any natural reactors, are there. :cry: Too bad.

But wait! Did I hear someone say Oklo (http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/index.shtml)?

[Morbius]

Wouldn't it be nice to have some natural reactors, with buried spent fuel and decay products, to study?

Nereid,

EXACTLY.

The natural reactors at Oklo and Gabon have been extensively studied.

It's been shown that soil is such a good ion exchange medium, that the
fission products get trapped and don't migrate very far in millions of years -
even though there were absolutely no measures taken to inhibit that
migration.

Contrast that with the Yucca Mountain repository - where the waste is
encapsulated in something like borosilicate glass, which is then encased
in steel containers....

The scientific consensus, as opined by the National Academies of
Science and Engineering, from our best Ph.D. level scientists state that
nuclear waste CAN be successfully contained, the opinions of unidentified
Navy reactor operators, nothwithstanding.

Dr. Gregory Greenman
Physicist