Can Radioactive Material Be Recycled?

[Arctic Fox]

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

Re: 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 shouldn't 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 shouldn't 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]

Recycled Resources...


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...

[/color]

 

[hitssquad]

Why spent fuel decay heat cannot be used to produce electricity

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. 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 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...

[/color]

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]

Why don't we reprocces nuclear fuel

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]

Jimmy Carter's 1977 reprocessing ban

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. . 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. 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 canceled 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 canceled 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 can't 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! 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! 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]

Some caviats related to the idea of solar waste disposal

Can we launch it into the sun?

According to the discussers of this on 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 that

Agreed. 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.

 

[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.

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.

 

[hitssquad]

Irretrievable disposal options for nuclear waste

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

I know what you saying, we would have to find volcano

No. He said, "...not with a volcano."

which is in state of continious lava production but not explosive

All volcanoes are at least potentially explosive.

Here 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 don't have to worry about subduction plate crushing vessels with waste.

 

[Colby]

According to the discussers of this on 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.

 

[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.

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]

Launching spent fuel into space.

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?

Isn't Am-241 inside smoke detectors?

And isn't Pu-240 weapons-grade material?

 

[hitssquad]

Weapons-grade plutonium

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% 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?

Isn't Am-241 inside smoke detectors?

And isn't Pu-240 weapons-grade material?

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 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