Hitachi Developing Reactor That Burns Nuclear Waste

Zothecula writes The problem with nuclear waste is that it needs to be stored for many thousands of years before it's safe, which is a tricky commitment for even the most stable civilization. To make this situation a bit more manageable, Hitachi, in partnership with MIT, the University of Michigan, and the University of California, Berkeley, is working on new reactor designs that use transuranic nuclear waste for fuel; leaving behind only short-lived radioactive elements.

Comments

Good

[geekoid]

Can we get more companies doing these please?

Re:Good

[Anonymous Coward]

I know of at least one other company that was developing this over 10 years ago.

If I recall correctly, the problem is that the US and Russia signed a treaty that prevent the reprocessing of nuclear waste. I expect that that treaty will not change, so unfortunately the problem will not be solved by engineering.

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[perpenso]

Can we get more companies doing these please?

Lets not forget the gov't research labs -- it would be nice if the U.S. gov't didn't shut down such research to appease an ill-informed political interest group.

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[newcastlejon]

Lets not forget the gov't research labs -- it would be nice if the U.S. gov't didn't shut down such research to appease an ill-informed political interest group.

Otherwise known as "the electorate".

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[Applehu Akbar]

Not a problem if Japan can just its own waste. If it works, everybody else will want one of these reactors too. What the US or Russia tthinkf pf this will be of no consequence.

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[perpenso]

Lets not forget the gov't research labs -- it would be nice if the U.S. gov't didn't shut down such research to appease an ill-informed political interest group.

Otherwise known as "the electorate".

No. Otherwise known as one particular political party's minority that has disproportionate power during primary season. Something very far from the electorate at large. Not to suggest the electorate is well informed on matters of science and engineering, but those few with deeply held political beliefs take scientific denial and misinformation to a new level.

Both political parties have their respective science deniers who will "primary" candidates who don't tow their line. Deniers have their respective articles of faith and all science and engineering to the contrary be damned. The two sets of deniers, each on their respective political extremes, are in fact so similar in their methods and circular belief systems its amazing. They truly are opposite sides of the same coin.

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[calidoscope]

The proposed reactor design sounds a bit like the EBR-II at INEL, formerly the National reactor test site, with the design also referred to as the Integral Fast Reactor. This program got shut down in the 1990's, though stories have been told about people who were sent out to Idaho to shut it down came back as converts to the cause.

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[calidoscope]

Electorate, schmectorate, decisions like this are based on who provides the most campaign donations.

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[Anonymous Coward]

Nope, we can't. The word "Nuclear" goes along with another few scary words, like "radiation", "terrorism" and "proliferation", hence the only people allowed to dab at it are large companies from a few pre-selected countries. Everyone else has either to pay obscene amounts to receive handouts in the form of a dangerous, but 'approved' technology, or face sanctions, or the odd terrorist act or assassination.

Given this, you won't have a lot of development. But you'll have huge, huge costs, massive schedule overruns, a lot of corruption, more 'safety' and less safety than optimal.

Nothing in the "nuclear industry" is an accident, even the accidents.

Re:Good

[Anonymous Coward]

It's great that you think that.

I'm not on either side btw, Australia doesn't even have a power-generating nuclear plant, we just ship all the uranium off to the rest of the world.

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[Anonymous Coward]

Or by redefining the boundaries of particular 'electorates' so that certain people's votes matter more than others

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[theshowmecanuck]

Russia and America aren't the only ones with nuclear generating stations. In fact they can't even claim to have the world's largest nuclear generating station.

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[wilfy]

Otherwise known as minority pressure, lobbying groups and vested interest..

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[Plumpaquatsch]

Not a problem if Japan can just its own waste. If it works, everybody else will want one of these reactors too. What the US or Russia tthinkf pf this will be of no consequence.

Most transuranic nuclear waste comes from making plutonium weapons - which Japan doesn't do AFAAK. Nor do all but a handful of states - if that many. The rest comes from the ca. 1% of spent nuclear fuel from NPPs that is transuranic - and that is almost completely Plutonium and will be taken out of that sliver anyway if reprocessed.

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[some old guy]

+5 Informative.

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[Eunuchswear]

If I recall correctly, the problem is that the US and Russia signed a treaty that prevent the reprocessing of nuclear waste.

You don't remember correctly.

Nuclear waste is reprocessed outside of the USA.

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[tomhath]

Jimmy Carter ordered a stop to all reprocessing. His decision was shortsighted and ill-informed, but at least what we call "waste" is still useful a fuel as soon as the ban is lifted.

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[LWATCDR]

No Nuclear is bad and dangerous.
Actually this is not new. Many reactor designs that do this have been tested over the last few decades. Also fuel reprocessing does much the same thing. You are left with a few highly radioactive elements with short half lives. Some of those elements could be used for research and some could even be used as power sources in RTGs.

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[melstav]

Either that, or other countries will start exporting their nuclear waste to Japan. Probably some combination of both.

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[Applehu Akbar]

Sorry for making that last post with my eyes dilated, folks. It's the only post I was able to make that day.

But yes: waste will be exported to the first country to develop a recycling capability for spent fuel. "Waste" is 95% usable fuel, which is precisely why it lasts so long if not treated.

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[rwise2112]

Russia and America aren't the only ones with nuclear generating stations. In fact they can't even claim to have the world's largest nuclear generating station.

And a CANDU reactor like this can already use waste from other reactors.

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[dave420]

You forgot one: "family".

*shudders*

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[sillybilly]

Not only can they cut their own waste, but conventional U235 is only like less than 0.5% of all U ore, and what these guys are after is the remaining 99.5% which is just as good nuclear fuel as that 0.5% if you got the technology to burn it and make heat out of it, for steam. I just did a whole serenade about bismuth, gallium, zinc vapors, sulfur vapors, molybdenum, niobium and ruthenium structural materials and fast neutron reactors, if you dig through my Slashdot posting history. I mean if you're one of these researchers who cares and is looking for ideas.

Re:Good

[sillybilly]

Oh yeah, and if liquid metal corrosion on structural walls only leaves gases as a high temperature option, Argon has loq cross section (unlike Kr, Xe), does not moderate, it's noncorrosive, so use it at 3000psi/1600C heated by white-hot glowing fuel rod banks, going through a turbine down the liquid Ar in vacuum, and then injected back, diesel style, to a high pressure and temperature, as a liquid spray. Hang rods that can be yanked out into a fully shielding isotopically pure silicon made cement absorber cavity, all of them all at once if necessary, for fast shutdowns. Do not use stacked balls that shift easily, and are impossible to remove the fuel rods quickly from the reactor zone into safely shielded concrete coffins, for an advanced fast neutron fuel breeder gas reactor.

Re:Good

[sillybilly]

And you have to plan big - no unmoderated fast neutron fuel breeder reactor is gonna be as small to reach critical mass as a moderated neutron reactor. Which leaves things like military ships and submarines out of this kind of game, and keeps them with small size, portable moderated reactors, but that's not a big deal when the fuel is so cheap it's not problem to waste 99.5% of it.

Re:Good

[Anonymous Coward]

Oh yeah, and if liquid metal corrosion on structural walls only leaves gases as a high temperature option, Argon has loq cross section (unlike Kr, Xe), does not moderate, it's noncorrosive, so use it at 3000psi/1600C heated by white-hot glowing fuel rod banks, going through a turbine down the liquid Ar in vacuum, and then injected back, diesel style, to a high pressure and temperature, as a liquid spray. Hang rods that can be yanked out into a fully shielding isotopically pure silicon made cement absorber cavity, all of them all at once if necessary, for fast shutdowns. Do not use stacked balls that shift easily, and are impossible to remove the fuel rods quickly from the reactor zone into safely shielded concrete coffins, for an advanced fast neutron fuel breeder gas reactor.

Ideally you don't want to "hang rods that can be yanked out" at all... what you want is passive safety, where you pull the rods *out* of the isotopically pure silicon made cement absorber cavity, and on a power failure or any other failure they fall back into safety by themselves.

Re:Good

[leereyno]

The meanie greenie vegeterrorists are not the electorate.

They're just single issue schizophrenics who make lots of noise.

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[sillybilly]

OK. So you lower them. Or hang them from above, and below, and you pull it from below, to guide it into the hole. It's a little more complicated than pulling up. If you don't pull from below, and it dangles about at 1600C glowing white heat, it may be hard to aim the tip to lower directly into the hole, unless you have, say, a whole yard clearance on each side. And at such temperatures concrete may not be stable, but instead you might need boron, or graphite loaded with boron, but graphite might ignite if there is a meteorite fireball crash into the reactor, and there oxygen access to it, but boron is both high melting point, and it covers with a glassy oxide that boils at 1860C, unlike CO or CO2 that's a gas. High melting oxides like MgO or ZrO2 both are solid to near 2700C, but their borates glasses might melt low. Neither MgO or ZrO2 absorb neutrons well, but Hf is decent, and similar in properties to Zr. So the ideal neutron absorbing coffin material might be Hf which melts at 2200C, and whose oxide melts at 2700C. Tungsten also burns in air, absorbs neutrons decently, but its oxides are lower melting and more volatile. They get all this Hf anyway when they clean it out from the Zr structural materials. Btw, ThO2, thoria is the highest melting oxide, a ceramic, at 3300C, and its useful as a nuclear fuel rod in that state, as long as it don't crack (you may need like a thin low thermal transfer resistant and low neutron absorbing molybdenum crucible to hold it in, hanging in the reactor space. But hanging is possibly not the ideal state under high velocity argon gas, but tethered at both ends probably is, so pulling down, or even falling down in case of a catastrophy, is probably best. You're right. Suppose the whole thing melts, and it falls down and melts the containment coffin material too and alloys with it. It still a successful shutdown when the neutron absorbers get melt-alloyed. Instead of tethered by a string in the bottom, they could have a dummy section even made of different materials, halfway stuck into the coffin-hole, and only the top part of the rod participating in the fast neutron exchange reactions, then you flip the rods. Once half of it is stuck into the slot (still having a lot of clearance from each side, how high can you go? a whole yard on each side?), in case of a meteorite hit catastrophe the rest should be nicely guided. You could also have a neutron reflector cover over the holes with less clearance, but lower melting pt than the coffin material, say zr that melts at 1855 or so, compared to hf at 2200 and moly at 2600, so in case of a runaway that gets the rods stuck in that cover, and a meltdown from that, the cover melts and drops the rods at 1900C, which is still lower than the 2200 hf melting point, so your coffin does not melt right away. I should go back and clean up this blah blah, and make it sound more professional, but I'm not doing that.

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[AutodidactLabrat]

The Electorate at large has been asked "Do you want a nuclear reactor visible from your home?"
NO say 88% of people. THERE, no "special interest" involved, just rational people making rational choices having observed how ever promise of 'safe, clean power' turns out to be an expensive, dangerous lie.

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[AutodidactLabrat]

Well that is why Pelosi is not speaker of the House despite the 5 million extra votes in 2012.

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[AutodidactLabrat]

Do remember to tell that to the people of Fukushima, and TMI, and Chernobyl, and Brown's Ferry, won't you?
Nuclear power. Big promises, little results.

I am the god of hellfire and I bring you

[Anonymous Coward]

Hitachi!

Re:I am the god of hellfire and I bring you

[Zynder]

I love Hitachi! It's soooo entertaining when they cook it all right there at the table in front you.

Re:I am the god of hellfire and I bring you

[ketomax]

Wanderful Magic!!!

Re:I am the god of hellfire and I bring you

[Anonymous Coward]

No, no, no, That's tamaguchi. Hitachi is the little grill thingie.

Re:I am the god of hellfire and I bring you

[Anonymous Coward]

I am the god of hellfire and I bring you...Hitachi!

Yeah, Arthur Brown sold out when he did that one, didn't he? ;-)

What's weird is that I could quite easily imagine that as a real 1980s advert. Mainly because- as a child of the 80s- there were a whole load of late-50s and 60s songs that I first became familiar with through bastardised-lyrics versions used in adverts (no doubt mainly aimed at my parents' generation, i.e. early baby boomers).

Re:I am the god of hellfire and I bring you

[bbsalem]

Yeah, I get what you mean, you burn up nuclear waste on your Hitachi and get short-lived isotopes that decay rapidly.Maybe they all come to Californium?

Already commented on this elsewhere

[AutodidactLabrat]

Baring that the new tech involves Neutron saturation transmutation, the end result will be MORE transuranics, as well as higher liklihood of meltdown, witness Fukushima Dai-Ichi's IMOX in #3. Total melt. Nothing new here, move along.

Re:Already commented on this elsewhere

[geekoid]

"as well as higher liklihood of meltdown,"
Nope.

Fukushima's error was that they didn't raise the sea wall like many recommendations had told them too.

They whole design is different, it's not really comparable.

Re:Already commented on this elsewhere

[TWX]

Will these new elements have significantly shorter half-lives? Will they themselves be able to function as fuel and could thus further be changed?

If both of these are true, even if they're still transuranics, then wouldn't it make sense to build a few of these reactors in geologically-stable areas?

We know the causes of the three biggest nuclear disasters, one being a maintenance task that went awry (TMI), one being an ill-considered test that led to meltdown (Chernobyl), and one being a natural disaster that caused the equipment maintaining the reactor to fail (Fukushima Dai-Ichi). We can probably avoid #2 and #3 based on good management techniques and proper site choice, and #1 is a matter of engineering/technical. If this would make it so that we don't have to attempt to tell two or three future civilizations how to avoid irradiating themselves then it might be worthwhile even if there are added volatility risks.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Mmmmmm, no, you can definitely burn up transuranics and you pretty much HAVE to end up with less at the end of the day, but the question is whether or not you have LESS OF A PROBLEM at the end of the day because there are plenty of "short lived" radionuclides that you really would rather trade for some nice plutonium or americium. On top of that the entire structure, premesis, possibly nearby things, etc will become waste, and even low level waste is costly to deal with. This is the same sort of set of issues that have made it totally uneconomical to reprocess spent fuel. ANY handling is messy, dangerous, and produces a lot of expensive to dispose of waste.

Re:Already commented on this elsewhere

[rogoshen1]

option A: moderate toxicity/radioactivity for (hundreds of) thousands of years
option B: EXTREME toxicity/radioactivity for decades

To me it seems a no brainer that option B makes infinitely more sense. The proliferation risks are honestly marginal, considering the alternatives. (increasing reliance on coal, or a never ending stockpile of option A. (So much of it in fact we're considering boring a hole in a goddamn mountain to stuff it into.)

The actors who'd be interesting in getting their hands on high level radioactive waste to cause mayhem would most likely be too inept to use it, and kill themselves in the process. The ones would be capable of putting it to use, probably have access to conventional weapons that would do more damage (consider a 'dirty' bomb vs a hijacked aircraft, or the type of bomb used in Oklahoma City.)

Re:Already commented on this elsewhere

[CrimsonAvenger]

premesis

I'm coming up blank on the relation between a prenatal multivitamin and nuclear waste.

So I'm wondering if you meant "premises", even though it doesn't fit all that well into your sentence either....

Re:Already commented on this elsewhere

[Anonymous Coward]

TMI isn't the third biggest nuclear accident, that honour goes to Kyshtym (cause: failed cooling system leading to steam explosion). And the Windscale fire was arguably a worse accident than 3MI (cause: lack of understanding of the growth of Wigner energy in the graphite used in the Windscale piles).

But such pickiness aside, such technologies as the one described are a Good Thing. (Hitachi are also developing a similar reactor called PRISM, which is a sodium cooled fast reactor designed to burn transuranics.) The idea is that these eventually fission all the TUEs into short-lived decay products. These are much easier to handle as decay products generally have short half lives and decay to inconsequential dose rate levels in a few hundred years as opposed to a few hundred thousand years.

Re:Already commented on this elsewhere

[brambus]

What is "neutron saturation transmutation"?
I'm also skeptical of their claims, as it appears to be a thermal-spectrum light water reactor and it's quite difficult to consume TRUs completely in the thermal spectrum, the neutron absorption cross sections are fairly large. Maybe they've got higher enrichment and so shitloads of excess reactivity, so they can afford to lose the neutrons, in which case I seriously hope they have a strong negative temp coefficient. Don't know, would be good to learn the details.
Not sure about the likelihood of meltdown being increased, though. I don't think the decay heat profile of MOX is significantly different from regular enriched Uranium fuel (decay heat melted Fukushima fuel, not fission heat).

Re:Already commented on this elsewhere

[Anonymous Coward]

Depends on how you design things. You would certainly want a waste handling plant colocated with the reactor in order to reduce waste handling; but once vitrified it's not really very difficult to deal with as long as you have somewhere to store it. At any rate not significantly more difficult to deal with than conventional waste, and it remains dangerous for a lot less long. Basically this doesn't add any new problems (yes even with conventional plants parts of the plant, structure, etc. become waste. You can maximise the amount that ends up as free release by scabbling off the radioactive stuff etc. but there's always some waste. But that's manageable.

Re: Already commented on this elsewhere

[Anonymous Coward]

I know they are mad about the leaked pics but that seems a bit far to go

Re:Already commented on this elsewhere

[perpenso]

Fukushima's error was that they didn't raise the sea wall like many recommendations had told them too. They whole design is different, it's not really comparable.

Not just the design but many other relevant circumstances too. I drove past San Onofre yesterday, currently inoperative. Noticed the really big hills immediately behind it. Putting backup generators and such on that higher ground might be useful too. I'm not 100% sure but I think backup generators were stored at the nearby US Marine Base, Camp Pendleton, and the Marines would helicopter them in if and when needed. If so on high ground, secured and mobile. Might be a better idea than more walls. Other coastal sites can probably take advantage of advantageous local conditions as well.

Re:Already commented on this elsewhere

[perpenso]

Will these new elements have significantly shorter half-lives?

In general the waste from a 4th gen reactor design is cited as being hazardous for a few hundred years. Something manageable, unlike the current situation where we are looking at tens of thousands of years.

Re:Already commented on this elsewhere

[brianwski]

> Fukushima's error was they didn't raise the sea wall

Also, the backup generators to operate pumps were in the basement that flooded. If the generators had been on the roof, it would have been fine.

I know hindsight is always easy, but it does seem like important stuff in a flood plain should be inspected and thought through once per year by smart people to find glaring problems like this.

Re:Already commented on this elsewhere

[Anonymous Coward]

I know hindsight is always easy, but it does seem like important stuff in a flood plain should be inspected and thought through once per year by smart people to find glaring problems like this.

How would you deal with the managers who have budgets to meet, and so defer said projects for quite some time?

My city has a physiotherapy pool that is on the verge of being closed because the local health board deferred maintenance for many consecutive years. Now, they're intending to close it because the damage caused by lack of maintenance is going to cost too much to repair.

This may seem like short-sightedness, and in many cases it could well be, but every few years this pool is used by the health board as a "We're low on funding! The city should spot us a few grand to shore us up..." blackmail tool. The council themselves have noted this, but have little choice in the matter; we need the pool.

Re:Already commented on this elsewhere

[khallow]

but it does seem like important stuff in a flood plain

Fukushima wasn't in a flood plain.

should be inspected and thought through once per year by smart people to find glaring problems like this.

The problem wasn't glaring except in hindsight.

Re:Already commented on this elsewhere

[Tailhook]

Fukushima Daiichi's problems began forty years ago when they removed the natural 35 meter bluff that use to be there.

The plant is on a bluff which was originally 35 meters above sea level. During construction, however, TEPCO lowered the height of the bluff by 25 meters. One reason for lowering the bluff was to allow the base of the reactors to be constructed on solid bedrock in order to mitigate the threat posed by earthquakes. Another reason was the lowered height would keep the running costs of the seawater pumps low. TEPCO's analysis of the tsunami risk when planning the site's construction determined that the lower elevation was safe because the sea wall would provide adequate protection for the maximum tsunami assumed by the design basis. However, the lower site elevation did increase the vulnerability for a tsunami larger than anticipated in design.

Not considered in the above would be the simple yet modestly more costly possibility of obviating the need for a sea wall by preserving the bluff and setting the reactors back, using modestly sized canals to cycle the sea water to and fro. That, naturally, wasn't the cheapest conceivable option, so it didn't survive the bean counters. Instead, they removed 25 meters of foothill, a feature that was originally 2.5 times the height of the tsunami before they fucked it up. The whole `bedrock' smokescreen is easily dismissed for the lie that it is; they could have reached bedrock from a setback design with no more difficulty.

This was done for one reason; grading the beach provided cheaper access to the ultimate heat sink, sea water. Less construction cost, less pumping, less maintenance, etc. This isn't lost on the perpetrators either. They know they're at fault and they knew it at the time, whatever lies they tell today notwithstanding.

This isn't speculation, either. Fukushima Daini did not get submerged, did not melt down and did not contaminate the land and the sea. Why? Primarily because it was built at higher elevation, which is about the only significant difference between these sites.

TEPCO bean counters. End of story.

Re:Already commented on this elsewhere

[MrKaos]

option A: moderate toxicity/radioactivity for (hundreds of) thousands of years
option B: EXTREME toxicity/radioactivity for decades

Well, fissile ash of option B would be radioactive for hundreds of years*n daughter products (n=roughly 20) so we would still have to bore a hole in a mountain to deal with it.

Re:Already commented on this elsewhere

[ShanghaiBill]

Fukushima wasn't in a flood plain.

The area is periodically inundated by tsunamis. That would fit most definitions of a "flood". If Fukushima wasn't flooded, then neither was Noah, since that was salt water too.

The problem wasn't glaring except in hindsight.

Nonsense. Plenty of people thought it was a problem before it happened. The area is hit by a big tsunami about every 300 years. There are historical records of the last few, and geological sediment records of many more. The last one was 300 years ago. They were due.

Re:Already commented on this elsewhere

[hidden]

I agree with your first statement, and I agree that Fukushima should have been prepared for that size of tsunami, but seriously.

The last one was 300 years ago. They were due.

THAT'S NOT HOW STORM FREQUENCY WORKS

Re:Already commented on this elsewhere

[Anonymous Coward]

I'm coming up blank on how you have managed to not get stabbed to death for being such a douche.

Re:Already commented on this elsewhere

[ShanghaiBill]

THAT'S NOT HOW STORM FREQUENCY WORKS

The tsunami was not caused by a storm. It was caused by an earthquake.

Re:Already commented on this elsewhere

[ShanghaiBill]

He blatantly made a biblical reference to Noah

The story of Noah did not originate in the Bible. Both the Sumerian Epic of Gilgamesh and the Akkadian Atra-Hasis Epic included the story centuries earlier.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Exactly! In terms of expense of dealing with radiation 100 years and 100k years isn't that much different from our perspective. In either case you want to contained, well contained. Honestly, transuranics are surely more expensive to house to some extent, but the question is if the extra cost is more than the cost of burning plus cooling/disposal/cleanup of these high neutron flux reactor designs.

Re:Already commented on this elsewhere

[camperdave]

option A: moderate toxicity/radioactivity for (hundreds of) thousands of years
option B: EXTREME toxicity/radioactivity for decades

Toxicity and Radioactivity do not necessarily correlate positively. You might wind up with highly toxic, low radioactive waste, or waste that has low toxicity but high radioactivity.

Re:Already commented on this elsewhere

[khallow]

The area is periodically inundated by tsunamis.

That's not what "flood plain" means. A flood plain is an area frequently inundated by a river. Else everything under about 1000 meters is technically flood plain (from nearby several km asteroid impacts).

Nonsense. Plenty of people thought it was a problem before it happened. The area is hit by a big tsunami about every 300 years. There are historical records of the last few, and geological sediment records of many more. The last one was 300 years ago. They were due.

Plenty of people knew including the builders of the plant who had constructed seawalls capable of withstanding a tsunami about 5 meters shorter than the one that actually hit. What they didn't know until much more recently was that tsunami could be considerably higher than the original 1 in a century events. For example, the earliest work I've seen anyone cite was from 2001. The study by TEPCO (the operators of the Fukushima nuclear plant) reached a similar conclusion much more recently (I recall some point on or after 2008).

For some reason, there's a lot of people here who think that such knowledge can magically transform into a higher seawall overnight despite the participation of several slow bureaucracies in the decision making and construction process. They don't trust these bureaucracies to run nuclear reactors, but they expect them to act instantly on new information and spend gobs of money to address any threat, real or imagined.

These same people seem to forget that Fukushima was scheduled to start its decommissioning in 2013 as well (yes, the life of the plant was extended, but not at the time that the higher seawall would have been evaluated). Why slap up a higher seawall when the plant will stop operating in a few years? One needs a better argument than that a very infrequent earthquake could happen during that period of time.

Re:Already commented on this elsewhere

[LordLimecat]

Im not getting how the removal of a bluff is the cheapest possible option, or how your brilliant suggestion addresses the earthquake concern.

Re:Already commented on this elsewhere

[Jack Griffin]

Noah wasn't in a flood because that is a fairy tale... Also the definition of "Flood Plain" may differ based on location. Where I live it is a legal term used as a covenant on property to distinguish land at high risk of regular floods (usually from rising rivers/poor drainage, so as to advise both potential buyers and insurance companies of risk. I'm not aware of any coastal property falling under this definition.

Re:Already commented on this elsewhere

[Anonymous Coward]

To someone with little or no brain, much is a 'no brainer'. However, extreme radioactivity brings extreme radioactive damage to whatever storage facilities you're keeping it in. So, storing very hlw may be much more dangerous or/and expensive than storing llw.

Re:Already commented on this elsewhere

[jafac]

soil and bedrock composition is probably different in California, but their Diablo Canyon plant is safe from Tsunamis, set up on a 30 meter bluff. It also has a gravity-fed emergency cooling pond, and is internally reinforced against earthquakes. The bean counters didn't win that one.

Re:Already commented on this elsewhere

[Cyberax]

What is "neutron saturation transmutation"?

Nuking it until it glows. First you separate your waste into constituent elements (their oxides, whatever) then you irradiate it with neutrons until most of the medium-level waste transmutes into something with a short enough half-life. You can optimize it a bit by playing with neutron energy to maximize the capture by most problematic isotopes. The size of neutron capture cross-section is not an issue, since you don't need those neutrons to support a chain reaction.

The concept is pretty old, but requires a shitload of neutrons (since you typically need to capture multiple neutrons to transmute a single waste atom). The only practical way to get that much is to use a fast neutron reactor. And even then it's marginal. In future, when we get fusion reactors, fusion neutrons could be used much more economically for that.

Re:Already commented on this elsewhere

[careysub]

The Hitachi press release contains absolutely no information about what might be new, unusual, or effective about their approach. They mention an undescribed new fuel core in passing, that's it. It would have been helpful if they had included something to give the sense that it is not pure hype.

Re:Already commented on this elsewhere

[careysub]

I agree with your first statement, and I agree that Fukushima should have been prepared for that size of tsunami, but seriously.

The last one was 300 years ago. They were due.

THAT'S NOT HOW STORM FREQUENCY WORKS

Seismic zones do however show patterns of periodicity of varying degrees of regularity. There is an underlying physical mechanism accumulating stress, and faulting must be triggered within a finite time limit given the finite strength of the fault zone (but may trigger sooner). Chances of a great earthquake absolutely do increase with time, dropping to minimal only after each major event.

Re:Already commented on this elsewhere

[careysub]

but it does seem like important stuff in a flood plain

Fukushima wasn't in a flood plain.

Yes it is. Take a look at this US Army topo map (the latitude is (37.427 degrees, its on the coast). It is on an extended flood plain stretching along the coast, created by several rivers (Takase, Maeda, Kuma. Tomioka, etc.) . The whole area is a sea-level marsh consisting of soil deposited by these rivers at flood.

The problem wasn't glaring except in hindsight.

Because, you know, no one had ever seen a tsunami in Japan before. Oh wait, tsunami is a Japanese word. That doesn't seem quite right, does it?

Japan had fifteen of them since 1900, before Tohoku (the slightly dated linked list misses the 2007 Niigata tsunami).

Re:Already commented on this elsewhere

[careysub]

The area is periodically inundated by tsunamis.

That's not what "flood plain" means. A flood plain is an area frequently inundated by a river. Else everything under about 1000 meters is technically flood plain (from nearby several km asteroid impacts).

Fukushima Daiichi is actually on a flood plain though. It is on an extended coastal sea-level estuarial marsh plain deposited by a series of rivers coming down from the mountains. BTW - there is no "frequent" required. Flood plain maps mark 100 year and 1000 year flood boundaries, something on the 1000 year boundary is still on the flood plain, even though that part floods rarely.

Re:Already commented on this elsewhere

[lisaparratt]

1 nail hammered through a testicle for each day they defer?

Re:Already commented on this elsewhere

[geogob]

Although, a tsunami has nothing to do with a storm or with weather and/or climate.

Re:Already commented on this elsewhere

[fuzzywig]

What do you do on day three?

Re:Already commented on this elsewhere

[GNious]

Depending on radiation exposure, you might be good for 5-7 days....

Re:Already commented on this elsewhere

[brambus]

Understood, thanks.

Re:Already commented on this elsewhere

[Eunuchswear]

Crimson Avenger has disabled his internet accessible knife.

Re:Already commented on this elsewhere

[thegarbz]

Your post fails the smell test.

As other's have pointed out you don't address how you preserve earthquake resistance, and quite frankly unless you're a civil engineer or reference one I don't give what you say much weight anyway.

You ignore the horrendous cost of earthworks involved in the modification. And then on top of everything you assume that a 25m change makes even a tiny bit of difference in a multi-billion dollar project. Sorry but access to the sea water due to the extra distance would have been lost in the rounding errors of the overall project cost. Selecting pumps with correct head and putting in the correct amount of pipework would have been trivially cheap compared to the earthworks you proposed.

Re:Already commented on this elsewhere

[LWATCDR]

" On top of that the entire structure, premesis, possibly nearby things, etc will become waste, and even low level waste is costly to deal with. "
Umm no.
The reactor and some parts will become low level waste not the entire structure.
Everything is costly to deal with the dismantling of a solar plant or wind mill is costly to deal with how costly?
This post is full of vague statements and errors designed to instill fear without knowledge.

Re:Already commented on this elsewhere

[Applehu Akbar]

It wasn't even the seawall height that was the real problem, since any seawall could eventually enounter a larger tsunami than it was designed for. Even the old reactor design used there is very forgiving in the sense that if the plant totally loses power after being scrammed and the backup diesel pumps don't work, you have plenty of time to connect an external coolant water source to the reactor and pump water through it for a few weeks to pull away heat of decay.

But at Fukushima the disaster was so large in scale that all the modern-day infrastructure surrounding the plant was washed away. A fire company eventually got through, but didn't have the right connector to join its pumper hose to the reactor. This is the kind of idiot basic stuff that makes acts of nature so much worse.

Re:Already commented on this elsewhere

[Applehu Akbar]

What you didn't mention was that your option B also means a much smaller volume of waste, because the unburned U of option A is gone. So you get hot short-lived waste, but at such small volume that the disposal problem becomes trivial.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Or its a nuclear chemist telling you how it really is. Gosh, sorry the world doesn't conform to your desires...

Windmills and solar plants may have to be dismantled someday, but they don't have effectively a finite lifespan due to extreme safety concerns which nuclear plants do, so the chances are slim that they WILL be retired. When elements of such plants DO get demolished this is just an ordinary demolition project and the leftovers are either recycled, used for fill, or etc. as appropriate. In the case of all of the operating equipment part of a nuclear power plant ALL OF IT is low level waste and has to be disposed of in specific ways. You don't have to believe me, just go and investigate for yourself. Now, the employee parking garage and some offices over on the other side of the site? Maybe not, they're probably just going to the landfill. However, at ALL FACILITIES that have dealt with some sort of processing of transuranics and longer-lived daughter elements very expensive cleanups have been required. Vastly more expensive than the often billion-dollar cleanups at power reactors. It is absolutely certain that anyplace that is opening casks and moving the stuff around that is inside them will have to do some chemistry on what's in there, and when they do they WILL MAKE A NASTY MESS. If you don't understand this, then you're too ignorant of the subject to be commenting.

Re:Already commented on this elsewhere

[NoImNotNineVolt]

Next you'll be telling me that the Biblical "eye for an eye" stuff was neither Christian nor Jewish but instead from the Babylonian code of Hammurabi.

Re:Already commented on this elsewhere

[LWATCDR]

Your statement was the entire structure and possibly the surrounding areas would be waste.
Windmills with have a defined max_life based of safety as well because most use aluminum for the blades. It will have a finite life because of metal fatigue.
Low level waste is just not nearly as dangerous as you are making out. It is just put in to a landfill.
Of course it is more expensive to decommission but this technology will greatly reduce the problems with waste. The simple truth is that to be anti-nuclear is to pro climate change.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Well, first of all I didn't say the whole area would be waste. I said the structures and etc would be waste. Of course nobody knows exactly what that would entail, no such facility has been built, but when I look at existing purex plants and other similar infrastructure that has handled high level waste and performed any sort of significant handling, it has turned out to be a very big mess. All I'm suggesting is that we have to consider this when we think about 'burning waste' and such things. I MAY not turn out to be the deal that its proponents claim. We don't know yet. That doesn't make me pro or anti nuclear, it makes me an intelligent human being who weighs all sides of an issue before declaring that its good or bad. When the evidence is in, then I'll decide. Until then I just point out the pros and cons and maybe what we can guess about their merit. You can do no better unless you have some font of otherwise secret knowledge about this subject that the rest of the world is lacking.

Re:Already commented on this elsewhere

[Anonymous Coward]

No, this is documented. Dig around for the siting plans.

Re:Already commented on this elsewhere

[Rigel47]

It's not hindsight though. Japan has centuries-old stone markers all around the coast saying "Do not build below this line!"

"Gee, boss, where should we build the nuclear power plant?"

"Along the coast."

"But it's not cooled with sea water?!"

"Along the goddamned coast!"

"Ok, but what about the backup systems?"

"Put them below sea-level in the basement."

"Sounds good!"

Re:Already commented on this elsewhere

[LWATCDR]

"Well, first of all I didn't say the whole area would be waste."
Yes you did this is from your post. The entire structure, premesis (sic), and possibly nearby things is the definition of the entire area and then some.
" On top of that the entire structure, premesis, possibly nearby things, etc will become waste, and even low level waste is costly to deal with. "

Purex at Handford was built in the 1940s under war time conditions. It was run under war time conditions during the cold war as well. It is not a modern example at all. It would be the same as using a DC-4 as your reference for aircraft safety.

Re:Already commented on this elsewhere

[Anonymous Coward]

>Also, the backup generators to operate pumps were in the basement that flooded. If the generators had been on the roof, it would have been fine.

At least one reactor went into failure mode prior to the tsunami. The quake alone was enough to ruin one of the four. The generators would have helped of course, but the whole Fukushima tragedy is a variety of bad failure modes.

Re:Already commented on this elsewhere

[micahraleigh]

The story originated when it happened, not when it was written down.

Are you from the US patent office or something? ;)

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Purex is a process, not just the place in Hannford where they ran it at one time. Its an example of what highly radioactive materials processing is like.

You have to understand, I've BEEN to some of these places. I've SEEN IT. I know what the physics is and the chemistry and a fair amount about the engineering. This level of radioactivity is devilishly hard to completely contain and when even relatively small amounts escape you have nightmares like groundwater contamination and fun things like that. Its NOT easy like you seem to think. You need to study the subject instead of just some idiot's hype about it.

And again, I'm not saying it can't be worth it. Maybe it IS worth it, but I can guarantee you there will be billions and billions spent on controlling the resulting mess. Its just the nature of the beast. If spending $40 billion on building and cleaning up such a facility saves $200 billion and there isn't a big environmental problem left over afterwards then fine, its worth it. You simply cannot automatically assume that will be the case. I'm sure Hitachi looked into it, but I would be careful to see what they were reporting internally to their board BEFORE they decided to go ahead, because that will be the conservative and less biased view of it. Once they get going its all gung-ho with these corporations. You really have to watch what they put out at that point, its often very optimistic at best.

Re:Already commented on this elsewhere

[khallow]

Sorry, I don't see that. The map has contour intervals of 100 meters and the swamp symbols don't extend to the coast in the stretch you mention.

Because, you know, no one had ever seen a tsunami in Japan before. Oh wait, tsunami is a Japanese word. That doesn't seem quite right, does it?

Japan had fifteen of them since 1900, before Tohoku (the slightly dated linked list misses the 2007 Niigata tsunami).

None of these tsunami were greater than the height of the sea wall at Fukushima. And having a large number of tsunami doesn't inform you as to how high they can get.

Re:Already commented on this elsewhere

[AutodidactLabrat]

Reactor #3, an IMOX fuel mix of 8% 238-Pu and standard 2% yellowcake, reignited fission after coolant shutdown. This is the problem with all transuranic 'consumers', they make more of fissionable transuranics as they age, becoming more able to sustain the chain without moderator (water).
Result is as seen, steam overpressure, cladding reversion, hydrogen gas overpressure and explosions....except the reaction doesn't stop until the melted mass dilutes enough with low-fission-probable sand...and concrete...and steel.
The fact that the 'lava' did not melt through containment is, at best, pure luck.
So, please do ignore 50 years of breeder prototype results, just do it somewhere far from the growing land.

Re:Already commented on this elsewhere

[AutodidactLabrat]

Actually, 2H-3H energy loss fusion will do the job and is both throttleable and capable of the necessary density. We don't have to wait for energy gain since we're going for energy gain via fusion...someday.

Re:Already commented on this elsewhere

[AutodidactLabrat]

All good right up to the liquid sodium that ignites on contact with air. Kind of kills the whole "safety first" claim. Witness Fermi I (actually, the ONLY thanks to the near-melt and fire). There's a reason no one is talking liquid metal cooled reactors anymore.

Re:Already commented on this elsewhere

[AutodidactLabrat]

I would have to say not, given that transmutation will not 'blue shift' any more than it will increase fission, and so your pile of 238U will simply become more and more 239-Pu. NOT a solution given we have no way to dispose of the stuff.

Re:Already commented on this elsewhere

[AutodidactLabrat]

238,000 TW sustained solar influx. 1% and we have no use at all for fission so, yes, there are alternatives and given the long storage times and costs, probably much less expensive / 500 years.
A 20 year half life still has to be stored longer than the U.S. has existed as a state. Too expensive.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

238U isn't a transuranic, by definition. You CAN OTOH burn up Pu 239, Americium, etc much faster than it would decay if you have a good neutron flux. I don't know of anyone who doesn't believe something like a 'traveling wave' reactor, or a fission/fusion hybrid wouldn't WORK, its just a matter of if it would produce economical results vs just burying the waste in a repository.

Re:Already commented on this elsewhere

[AutodidactLabrat]

so are you thinking of an IMOX of 238Pu and heavier with some lighter element such as aluminum? Otherwise, the waste matrix will be in 238U, which will just produce more transuranics under relativistic neutron bombardment.
I am thinking the mix will be the latter, since any reactor that doesn't produce enough power to pay for the costs of operation will necessarily go under.
I am, naturally, hoping no one is thinking 100% transuranics with a 235U core to provide the bombardment....given that the operational word might very well become "bomb" under those circumstances.

Re:Already commented on this elsewhere

[AutodidactLabrat]

I am curious, but I wonder why these earth shaking technical improvements are so lacking in details by the PR flacks.
Could it be that nothing new has been added and they are just looking to restart the nuclear industry, which is, frankly, dead in the water for at least a generation thanks to Fukushima demonstrating how little regard the reactor industry has for safety.
One spreading room for six reactors, and that below sea level. Seriously.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

The implementations I've seen bandied about are primarily 'TWR' type designs where the fuel is roughly 90% U238 and 10% U235 or Pu238. These are ESSENTIALLY fast breeders, but they are capable of burning up about 35% of their fuel in a single cycle. The resulting spent fuel can be remelted and recycled through the reactor without chemical separation. Because existing spent fuel from LWRs is still mostly fertile U238 it can be utilized directly to feed a TWR. Obviously a TWR wouldn't be 'waste free', there will be daughter elements produced as in any reactor, etc. In fact it has been characterized as a rather tricky type of reactor to build, even for a breeder, and eventual decommissioning would be fairly nasty. HOWEVER due to the vastly high fuel use efficiency a TWR could essentially just be fueled once and sealed with no provision for refueling at all. Conceivably the core could be designed such that it would simply be removed and replaced after 40 years, at least in theory. Reality is more like you'd end up with a very hot core that would still have to be disposed of, but this would amount to a very much smaller amount of waste than with an LWR. The beauty of this sort of system is that you can burn depleted Uranium there are VAST stockpiles of the stuff around, enough to fuel 1000's of TWRs for millennia (the US alone has over 700,000 tons in inventory).

I'm not advocating these things, but if some similar sort of design is what Hitachi is talking about, then it certainly would be able to burn waste. I can see the lure. I suspect there are a lot of these heavy industry corporates that have nuclear expertise that are keeping these kinds of projects on low simmer somewhere thinking that maybe in a decade or two the world will be banging on their door desperate for a clean energy solution and willing to put up with nuclear power. Its possible they are right. Frankly though I doubt they will push it through to an actual build of anything in today's climate, but perhaps in 5 or 10 years when they are good and ready things will be different. At least by then they may have a good idea whether such a concept is really economical.

Re:Already commented on this elsewhere

[Ihlosi]

You CAN OTOH burn up Pu 239, Americium, etc much faster than it would decay if you have a good neutron flux

Unfortunately, "burning" Pu and Am just turns one kind of problem ("radioactive, but chemically relatively inert heavy metal") into multiple problems ("mix of fission products with highly variable chemical properties and half lifes"). And since you can't burn 100% of the initial Pu and Am, you'll still have to deal with the original problem.

What we need is the "minimum binding energy" reactor that uses any atom (except for iron) as a fuel and produces stable iron isotopes as waste.

Re:Already commented on this elsewhere

[AutodidactLabrat]

As mentioned by others, a reactor dependent on MeV neutrons will be VAST and your 10% 235U would make such a reactor subject to neutron pulse runaway.
If made of 238Pu you just have vast and unmoderated (meaning loss of coolant does not halt fission, losing one failure mode defense in the process).
Now you are down to less reliable active controls and...if Americans have learned anything they have learned not to trust active controls 'certified' by the Nuclear Industry of TMI fame.
Seriously, catastrophes can not be tolerated and if Fukushima did not end the insanity of fission power, it is only due to the mega billion dollar propaganda blitz.
Like all fission technologies, you are asking the people to trust those who have been shown willing liars and we're all done with that trust.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Sounds good to me, let me know when you have a design and I'll fund it!

Re:Already commented on this elsewhere

[Giant Electronic Bra]

I'm not asking for anything, I just described ONE POSSIBLE technology that Hitachi could be working on. Honestly I don't know a large amount about the safety characteristics of such a reactor, but it doesn't appear to be 'vast'. I'd suggest doing some general reading on the subject. These ARE liquid metal cooled reactors, with all that implies and I'm NOT saying I think they would be safe, etc. Don't mistake me for one of the blind followers of the nuclear light. I don't think all nuclear power is The Devil necessarily, but I'm a pretty deep skeptic on the subject. Still, I can see the allure of a technology that could in principle supply 'clean' power for 1000's of years using nothing but existing stockpiles of a substance that is generally considered useless and could burn up troublesome waste.

Re:Already commented on this elsewhere

[AutodidactLabrat]

Yes, there are liquid metal reactors, and all of them currently use Be or C moderators and a more conventional 235U core with or without external augmentation of either 232Th or 238Pu.
But the bottom line for this advertized 'breakthrough' is that it will burn semi-stable transuranics.
That absolutely and always means relativisitic neutron bombardment, with concommitant low impact probability per neutron / cross sectional / meter, thus 'vast', as in a great mass, well in excess of 55 tons, of fuel, and it will probably have to be pure metal fuel at that, with the 'shudder' factor this produces
What nuclear engineers and their users refuse to acknowledge is that control systems fail, in unexpected ways, when non-modeled behaviors are introduced...like tsunami in coastal waters which are seismically active subduction zones.
And quite simply the allowable failure rate for a reactor in the unmodeled situations must be ZERO, none whatever.
That requires passive safety, which is, necessarily, expensive and ordinarily unused.
So now we speak of reactors without passive fission damping from loss of moderator (coolant) and just HOPE we never get another 'neutron wave' event like the experimental reactor failure at SL-1, caused then by a mis-application of withdrawal rate of the central control rod.
These things have to be treated like chained volcanoes. We have all learned that the industry cannot be trusted to police itself and sadly, many of the scientists involved in pacifying the public while pushing the design envelope have proved to be, shall we say, less than trustworthy?

Re:Already commented on this elsewhere

[Giant Electronic Bra]

You're largely preaching to the choir here, but you might want to read the papers and etc on the Terrapower design because it sounds like it isn't quite how you are envisaging it. OTOH I agree, a liquid metal cooled breeder/fast neutron reactor is not going to be passively stable and not going to be inherently stable at all in the same way that a uranium oxide fueled PWR is basically stable when properly designed and won't spike to 50 or 100x its designed power output (like the nice Russian graphite reactors are prone to do).

Re:Already commented on this elsewhere

[AutodidactLabrat]

Be very hard to do since they took down their page

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Interesting. Well, frankly I've always thought these various initiatives were doomed. Its a LOT harder to design a nuclear reactor than people seem to think.

Re:Already commented on this elsewhere

[AutodidactLabrat]

No doubt about that. Remember gaseous fission reactors? Real soon now, flying nuclear airplanes..any day now...soon.
The LFTR's? Seems someone forgot to do their homework on self-sustaining Thorium and so, yet another failed effort before it even began (Sorenson notwithstanding).
Breeders, all 5 nations who have worked there have all retreated.
And off topic, the ITER. Same old same old Tokamak, any day now we'll beat all those nasty instabilities and have 'control' over these little suns...not.

Re:Already commented on this elsewhere

[Giant Electronic Bra]

Tokamak's MIGHT work, actually probably WILL work. Big question if they can be economical or not. LFTRs definitely CAN and DO work, that's been conclusively proven. Again its a question of whether they would be economical and if they will actually be safer, cleaner, etc. which are unproven assertions, though they have some basis in the underlying physics.

Re:Already commented on this elsewhere

[AutodidactLabrat]

The first Tokamak was circa 1959. They don't work. Plasma instabilities in self-heating arrays always collapse chaotically. LFTR's cannot work. They MUST have an external neutron source or,,,drumrolll please, why is 233U not sold to enrich yellowcake? See? Or used in bombs? Sorenson can kiss my rosy red rectum, they don't work

Re:Already commented on this elsewhere

[AutodidactLabrat]

Oh, wait, you said LFTR's have been CONCLUSIVELy proven to work. SHow me the operating commercial scale NO uranium / Plutonium cored LFTR. Oh...wait..

First...

[Anonymous Coward]

...link doesn't work. Sorry couldn't resist :)

Re:First...

[gargleblast]

Excellent. Dice Holdings' new HTML anchor design has gone into beta.

Nucular wands.

[fragfoo]

This is just so they can build more powerful wands.

No mention of thorium

[Tinsoldier314]

Don't LFTRs solve the same problem?

Re:No mention of thorium

[brambus]

I don't think they do so in the breeder cycle - their neutron loss margins are fairly thin, hence why most designs propose extracting at the Pu-238 step (unusable for weapons, but great for space batteries). The burner cycle might be better in this regard. Fast reactors are able to do it, they have plenty of neutrons to spare.

Re:No mention of thorium

[knapper_tech]

I was confused about the use of water and burning Actinides because I believe it requires fast neutrons to occur at a high rate and water is a moderator. Also, if water getting out of the way lets the reaction rate increase, the void coefficient would be positive? I'm not sure which mechanism they intend to operate to burn the Actinides, but it sounds like they're trying to push derivative technology as being a safer, more reliable road in terms of tooling and design. This explains nothing of how the reactor can burn Actinides, much less how effectively and efficiently.

Although RBWRs use new core fuel concepts to burn TRUs, they use the same non-core components as current Boiling Water Reactors (BWRs), including safety systems and turbines.

They could be a little more specific.

Re:No mention of thorium

[knapper_tech]

If the Actinides already exist in abundant quantities, then they don't need fast neutrons?

Re:No mention of thorium

[brambus]

They don't, but the ratio of absorption to fission in the thermal spectrum for them is pretty bad, so that can mess up your neutron budget. Depends on the exact composition, though - each reactor produces a slightly different mix and that makes the TRU content in spent fuel fairly heterogeneous, which complicates reactor design and makes fabrication of reliable fuel fairly expensive (hence why MOX fuel only contains the Pu content, not all the other TRUs and even so it's much more expensive than fresh Uranium fuel).

Re:No mention of thorium

[MrKaos]

I was confused about the use of water and burning Actinides because I believe it requires fast neutrons to occur at a high rate and water is a moderator. Also, if water getting out of the way lets the reaction rate increase, the void coefficient would be positive?

It's a good point. I thought using water for a fast neutron reactor was something we had already moved past and were now considering using liquid metal, like lead, as a coolant with the reactor moderated by the design characteristics. Especially considering how volatile and unforgiving a fast neutron reactor is, taking out as many human factors as possible would be in line with recent NRC recommendations of removing "external" factors.

They could be a little more specific.

Like the burn-up rate they hope to achieve, if it is less than 10% then I don't really see any point here.

Duh

[Cyberax]

If you have a strong enough neutron flux then you can burn the waste (i.e irradiate it until it transmutes to something with a short-enough half-life). Unfortunately, only fast neutron reactors have neutron balance good enough to allow a significant fraction to be diverted for uses other than supporting the chain reaction.

Broken link?

[BringsApples]

Try here: new reactor design.

First Link is Broken

[knapper_tech]

Rendered for me as with no href. Second one works.

By far not the only design that does this.

[quax]

By I much prefer inherently safe reactor designs.

Re:By far not the only design that does this.

[brambus]

I never quite understood the allure of ADS. To my eyes it just looks like an exceedingly difficult way of achieving criticality. Given a good design, a reactor will self-regulate by its own negative temperature coefficient, so an external driver isn't strictly necessary and shutdown can be performed by passive systems that are equally dependable as cutting power to the accelerator, e.g. by suspended or spring-loaded SCRAM rods. There is the interesting proposition of not having to reprocess the fuel when running a thorium breeder cycle in order to extract the bred fissile and load it into the core, since one can boost the neutron budget externally, but that needs to be weighed against the pretty steep cost of a high-powered accelerator (in terms of current, not just particle energies) and accelerator reliability issues.

Re:By far not the only design that does this.

[quax]

Don't think accelerator reliability issues are much of a concern any more, the systems are pretty mature at this point. I see the many advantage in being able to produce tailored neutron energy spectrum to process as much waste as possible.

The latter is the main focus in my mind. Excess energy is just an added bonus. We need a process like this as burying the nuclear crap has become a politically untenable.

Re:By far not the only design that does this.

[brambus]

I agree that burning the crap off is a good thing, but why tack on an expensive piece of extra equipment when pretty much the same effect can be achieved by being smarter about core design? I'm just not seeing the big advantage here.

Re:By far not the only design that does this.

[quax]

One advantage that is purely political is that sub-critical reactors will be more political acceptable.

Re:By far not the only design that does this.

[camperdave]

I agree that burning the crap off is a good thing, but why tack on an expensive piece of extra equipment when pretty much the same effect can be achieved by being smarter about core design? I'm just not seeing the big advantage here.

By all means, let's move forward on the smarter core designs. However, we still have lots of waste from the older cores to deal with.

Re:By far not the only design that does this.

[Cyberax]

Except that they aren't safe. Even though they are subcritical, they'll still contain plenty of fuel. So there'll be more than enough decay products remaining to cause a meltdown in case of the coolant loss accident.

Re:By far not the only design that does this.

[Scottingham]

Another huge problem is that they have no idea what to actually use to contain the coolant loop.

Lead and Lead/Bismuth coolants are VERY corrosive and require active purification in order to keep oxygen levels down to incredibly low levels. Otherwise it'll corrode steel in a matter of weeks.

There are several proposed alloys or coatings but as far as I can tell none of them have made it past initial research phases and all have their own downsides. Like, one may have good thermal characteristics but has a large neutron cross-section or another may have a small neutron cross-section but get very brittle with temperature differentials.

Couple this with the fact that the accelerator is pounding protons (H+) into a spallation source (lead typically) and you have a whole other host of problems. Hydrogenation of the metals can lead to really bad effects with some alloys.

As far as I can tell this is the primary thing that is holding back the Lead/Lead Bismuth fast reactors. Sodium cooled reactors have more research behind them but also contain their own host of problems (like exploding when in contact with air/water, nbd).

Re:By far not the only design that does this.

[brambus]

Yeah, I'm aware of the problems with corrosion of high-temp lead, though this can somewhat be kept in check by limiting the temperature (it hurts efficiency, but might be worthwhile - really depends on the design). It really comes down to materials science and like you say, research on lead cooling has been thin so far. I'd love to see a lot more open-access research in this area.
As for sodium cooling, it has its own problems, but AFAIK it doesn't react explosively in air. It can burn, but if I understand it correctly, the reaction isn't exothermic, so it'll quench itself quite rapidly. Now water is a different story. A sodium-cooled reactor in a potential flood area (ahem, Fukushima Nr.1) is about as dumb an idea as I can think of. Fortunately, the improved thermal efficiency gives you some more leeway to run pumps and pump the water up a hill (like reactors #5 and #6 at the Fukushima Nr.1 plant, which were largely unharmed by the tsunami which totally devastated their lower-sited siblings).

...it can be broken down into near-nothing?!

[Anonymous Coward]

...why didn't science just do this in the damn first place?! ...but what does the "short-lived radioactive elements" dissolve into? surely not *nothing*? ...how much can we strip away through processes before every part is used? ...how little matter do we need left over before we can eject it from the Earth's atmosphere into the Sun?

Re:...it can be broken down into near-nothing?!

[The Grim Reefer]

...why didn't science just do this in the damn first place?!

It's never been cost effective. The same way safe coal mining and 100% safe fly ash disposal isn't cost effective. If you need to expend more energy to deal with the waste than you get out of it, it's not worth it.

....but what does the "short-lived radioactive elements" dissolve into? surely not *nothing*? ...how much can we strip away through processes before every part is used? ...how little matter do we need left over before we can eject it from the Earth's atmosphere into the Sun?

If we get it to the point that it's economical to launch in a rocket, then there's so little left that storage shouldn't be a big deal. And if it's safe enough to put on top of a rocket, then it doesn't need to be removed from our biosphere.

Most of the really radioactive waste is extremely dense. So it gets insanely expensive to get it out of earth gravity well. To make matters worse, we have no space launch systems that are reliable enough to use for this type of disposal. It's one thing to have a bunch of highly radioactive material sitting around in a shielded location. It's an entirely bigger problem to have a failed launch blasting toxic crap all over hundreds or thousands of square miles/kilometers.

It's also a waste of of non-renewable material with a high amount of potential energy that we may be able to do something with sometime in the future as our understanding of physics progresses.

Even ignoring the huge amount of energy required to launch something into space, our current launch vehicles are not the most environmentally friendly mode of transportation either.

It's a very small problem

[Gliscameria]

Nuclear waste is only a problem if you have a massive misunderstand as to the scale of the waste. We're not talking about literal mountains of waste, we're talking about under 100,000 tons - for all of it from the USA since forever. You can do one big project and store all of it, nearly indefinitely. The story of Yucca Mountain is what happens when you have to involve people that want a project to fail instead of just getting the damn thing done.

Re:It's a very small problem

[PPH]

Nuclear waste is only a problem if you have an agenda to make it one. Scream about the evils of reprocessing and the long life stuff piles up, eventually making nuclear power uneconomical. Perhaps that's what some people had in mind from the beginning.

Re:It's a very small problem

[Anonymous Coward]

Once upon a generation there was a nation that generated a 100,000 tons of material that killed people for thousands of years, The killing people they considered bad, but the making part was considered good because it made profit for the magic hand.

As is its wont Time went by and then more time and even more time , the original people died and new ones were born to take their place. Each generation having a stronger belief in the power of Jeebus and the magic hand and less able to read, write or understand the magic their ancestors.

Everything was fine until one day a generations in their ignorance ignored the warning signs and moved near the dreadful holy mountain and muted into cannibalistic monsters who ate all the remaining amurkins.

Re:It's a very small problem

[AmiMoJo]

For it is not nuclear waste, it's unspent nuclear fuel.

Fuel for an imaginary reactor you hope you can build at some indeterminate point in the future. Or are you aware of someone building a commercial one?

Re:It's a very small problem

[Anonymous Coward]

There's more to nuclear waste than unspent fuel. It also encompasses used storage containers, old equipment, contaminated coolant, etc. That can fill up a lot of space pretty quickly and isn't very useful as a fuel source. I don't see how it could be radioactive for thousands of years either though, since it's not the actual fuel.

Re:It's a very small problem

[Areyoukiddingme]

Fuel for an imaginary reactor you hope you can build at some indeterminate point in the future. Or are you aware of someone building a commercial one?

Yes, he is. Did you not see the reference to China? China sent representatives to tour Oak Ridge National Laboratory. They patiently listened to all the nanotech PR, then asked about molten salt reactors. They got everything. They're working on continuing the work Oak Ridge stopped doing decades ago, starting from what Oak Ridge had.

He made up the bit about 2020, since they said nothing about schedule, but they've publicly admitted to working on molten salt designs.

Oh, and the person leading the project is very tightly connected to the ruling party. Meaning they will get resources and approvals and whatever it takes to get the job done. China has a massive latent appetite for electrical energy. They're pursuing every possibility in order to get more.

Properly processed?

[Anonymous Coward]

I'll admit to not being an expert in any way on the subject, but my understanding is that the whole "thousands of years to become safe" is a product of the NIMBY crowds red taping to death our reprocessing facilities. "Nuclear waste" is actually still mostly usable fuel, it just has some impurities in that that makes it unsafe in a reactor. Reprocessing can remove those impurities and then you can put the "waste" right back into a reactor. The impurities are highly radioactive, but they burn off their radioactivity within a few hundred years reverting to a level equal to naturally radioactive elements.

It's easy

[ArcadeMan]

They'll just modify the nuclear waste so that it becomes perpendicular.

Re:It's easy

[sound vision]

No, it will simply grow a face and "get perpendicular" of its own volition!

Water cooled, TRU burning reactor = BS

[macpacheco]

Humm, let's see.
U-238 absorbs a neutron becoming Np-239 then decays to Pu-239
Pu-239 has only a 2/3 probability of fission upon neutron absorption
Water also has the tendency to absorb neutrons
It's no wonder that no TRU burning reactor has been proposed that uses water or helium for cooling, it's always sodium, lead or molten salt as coolant.

Also weird, is Hitachi already has a TRU burning design, the S-PRISM (GE/Hitachi project). Fast sodium reactors are actually known to be workable for that job.

Re:Water cooled, TRU burning reactor = BS

[brambus]

It's possible they plan to only burn stuff beyond Pu in there, as that can already be consumed in MOX (which however produces more of the higher TRUs for the reasons you noted). It's really hard to tell what they're trying to do here without more detailed data on the actual fuel composition.

Also weird, is Hitachi already has a TRU burning design, the S-PRISM

It's possible they're having trouble getting a dedicated TRU burner design approved and built (there might be little economic incentive and much public opposition to new nuclear plants, no matter the safety of the technology), hence why they might be motivated to try and design fuel that can consume TRUs in standard BWRs, of which Japan already has quite a few.

Re:Water cooled, TRU burning reactor = BS

[macpacheco]

Any water cooled reactor is inherently less safe than a metal or salt cooled reactor.
Water/Gas cooled reactor = high pressure
Anything else = low pressure
Fully passive safety has been demonstrated with sodium and molten salt reactors.
While AP1000 can be shutdown and kept cool without active safety systems, it does require lots of complex active systems while in operation.
Still, non sense.
PS: Any design that claims to burn TRU must be able to fission at least all transuranics. Any really great design will purposedly also burn U-238 present in SNF from water cooled reactors too.

Re:Water cooled, TRU burning reactor = BS

[brambus]

I'm not a fan of light water reactors either, but you need to understand that the public isn't aware of the details and intricacies of reactor design. To them terms which make an engineer cry happy like a little girl, don't mean anything. I mean FFS most of them still think nuclear reactors can explode like atom bombs. They saw Chernobyl and Fukushima, they saw "boom", it's a nuclear reactor, therefore "nuclear boom".
I also think and hope education can change that, but that's a long road ahead and TRU-burning BWRs could work in the interim to help jumpstart that (since we already have them).

Re:Water cooled, TRU burning reactor = BS

[Anonymous Coward]

> Water also has the tendency to absorb neutrons

Uhhh, no.

http://en.wikipedia.org/wiki/Neutron_cross_section#Typical_cross_sections

Nice to see

[DaMattster]

This is nice to see and it is far more practical, in today's technology, than fusion. It's a way to keep existing technology working and reduce dependence on fossil fuels. I'm all for it!

We need robust research, not conclusion jumping

[Anonymous Coward]

There are lots of good ideas for feasible/safe-enough/cost-effective nuclear power, but none so far is proven commercially viable. Let's do lots of research and see if we can make it work. If not, let's not fool ourselves into believing that it does work.

Already commented on this elsewhere

[Anonymous Coward]

check it out, when you call some actinides transuranics, then you can fearmonger about creating more of them. pretty cool!

It's a very small problem

[Anonymous Coward]

>Nuclear waste is only a problem if you have a massive misunderstand as to the scale of the waste.

Incorrect, sir. Nuclear waste is only a problem if you have a massive misunderstanding as to the thing you apply the label of nuclear waste. For it is not nuclear waste, it's unspent nuclear fuel.

It would be foolish to build a massive pointless structure for nothing. Nobody's moving their nuclear "waste." It's not even waste to begin with. It's fuel.

Have you ever heard of a Molten Salt Reactor? The most famous one I know about is the LFTR proposed by Kirk Sorensen. These types of reactors also burn existing nuclear waste, but they do so at atmospheric pressure, and are inherently safe. See: http://www.investing.com/analysis/thorium:-an-alternative-source-of-energy-224358

We could build MSRs on site, so the fuel never has to be transported anywhere. Then we decommission the old dangerous water-based plants and run the safe waste-consuming molten salt reactors.

OCCUPY CARSON CITY presented this idea to the Nevada Committee on High-Level Radioactive Waste 7/2012. https://www.leg.state.nv.us/Interim/76th2011/Committee/StatCom/HLRW/Other/ResponsestotheSOR.pdf

This article confuses me because the Hitachi design is terrible. It uses pressurized water, which introduces all sorts of problems. The Molten Salt design is obviously better. I guess we'll just have to wait until 2020 to see how China does it.

How about protons instead of neutrons?

[Albinoman]

Seems like a stream of protons (which is really just hydrogen ions) could be fired at nuclear waste to get it to split without making the next thing down the chain so neutron heavy as to make it radioactive itself. I would like to know how boiling radioactive waste is supposed to drop the half life. If it does I have some physics to brush up on.

Re:How about protons instead of neutrons?

[russotto]

I'm pretty sure the energy required to add a proton to the nucleus of a large atom is prohibitive.

Re:How about protons instead of neutrons?

[Albinoman]

I guess I should ask what you mean by "pretty sure". Adding to large atoms are a lot easier than small ones. It's been a long time since I've read about it, but it's called "proton induced fission". Admittedly, most of the reading when you Google it is a bit heavy. I do know that if you crack U238 with a proton that all 3 daughter isotopes have a half life of 35 days or less (one is like an hour and a half) and their daughter isotopes are all stable.

Anyway, if you Google "proton induced fission" and "nuclear waste" together you'll see there are already papers proposing the idea, such as this one:

http://www.npl.washington.edu/...

Just may be the solution to global warming

[iamacat]

Clean power that can bridge capacity/fluctuation problems of solar and wind is just what we have been waiting for. I hope all the world governments tax rebate and finance the heck out of this to bring it to market in time to make an impact on worst effects of climate change.

Re:Just may be the solution to global warming

[Anonymous Coward]

Nuclear doesn't really scale. It's on or off (or a collection of smaller reactors that are on or off), and the startup costs are fairly problematic. In a combined power arrangement, nuclear would provide the major baseline of power, with solar, wind, and other inconsistent sources helping to provide the daily variance, and a very easily scalable source like natural gas filling in slack as needed.
Better batteries would increase the effective stability and control of uncontrolled sources, but even with modern technology this arrangement would greatly reduce pollution from power generation.

Highly interesting results if true

[brambus]

Had to google the abstracts of the report and its conclusions are highly interesting. They claim to be able to breed at a ratio slightly above 1.0 in a BWR and even slowly consume TRUs by 10% per reprocessing step with unlimited reprocessing capability. Results of the report:

The analyses collectively indicate that the two reactors appear to be able to achieve their design objectives: The RBWR-AC provides an equilibrium-cycle breeding ratio of slightly above 1.0, thus providing for a self-sustaining fuel cycle in which depleted uranium is used for the makeup fuel. The RBWR-TB2 is capable of unlimited continuous recycling of TRU while consuming on the order of 10% of the loaded TRU per recycle (after accounting for the newly generated TRU). Most results confirmed the values estimated by Hitachi. Some differences among the predicted reactivity coefficients need to be evaluated further.

This has the potential to be a game-changer if true, as we could simply use existing reactor designs such as the ABWR (of which there are several operating already) to both burn waste and breed fuel indefinitely from U238 feedstock.

Magic wand?

[neonleonb]

It's Hitachi! Can't they just wave their Magic Wand and make the nuclear waste go away? Think of the buzz that would create!

The nuclear industry had it's chance

[Anonymous Coward]

Not everyone is a scientist, the list of disasters from profit driven nuclear means that people just won't accept it, unless they are forced to.

how apropos

[Tumbleweed]

Hitachi means 'sunrise'. :)

So when the Canadian wheelchair assassins roll in

[Anonymous Coward]

. . . in some corporate-subsidized dystopian future where a plague of mega-flora and -fauna have forced us to experialize the better part of the Northeast, and they proceed to terrorize us with a video so entertaining we die in piles of our own filth before we can be pried away from our screens: remember that we were warned.

Sorry, but anyone who claims that ...

[Ihlosi]

... transuranic elements are the only long-term problem in nuclear waste should please stay the hell away from designing nuclear reactors.

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

And that doesn't include "medium-lived" fission products like Cs-137 and its buddy Sr-90, both of which have half-lives of about 30 years.

Re:Sorry, but anyone who claims that ...

[Anonymous Coward]

And that doesn't include "medium-lived" fission products like Cs-137 and its buddy Sr-90, both of which have half-lives of about 30 years.

that part actually doesn't sound too bad at all

Re:Sorry, but anyone who claims that ...

[Ihlosi]

that part actually doesn't sound too bad at all

It means that the stuff needs to be stored safely and away from the biosphere for about one thousand years. That's still several human lifetimes.

Re:Sorry, but anyone who claims that ...

[david_thornley]

Thirty years is bad. The radioactive iodine that came out of Fukushima is all gone now, not an atom left. The half-life's about eight or nine days, so it's really hot while it's there and in a few years it's all gone. The long-lived stuff isn't that dangerous from radiation (your biggest risk would be heavy metal poisoning). Thirty or forty years means the stuff's dangerous and significant amounts of it will remain after several generations.

Re:Sorry, but anyone who claims that ...

[Ihlosi]

The radioactive iodine that came out of Fukushima is all gone now, not an atom left.

Oh, the I-129 will stick around, with a half-life of just below 16 million years.

Re:Sorry, but anyone who claims that ...

[david_thornley]

Sorry, thought that was all I-131. Of course, I-129 isn't going to be high-level waste, given that half-life, and the fact that it beta decays into a stable isotop.

The thing I worry about

[Chas]

Is that this is another solid fuel, boiling water reactor. Which means they have all this Rube-Goldberg-esque over-elaborate over-engineering to control the plant in a shutdown state. And if they miss even one little thing, boom. Steam explosion.

While burning up existing reactor wastes is a Good Thing, there are better, simpler, safer reactor designs for things like that.

It's mostly a USA problem

[kriston]

It's mostly a United States problem that waste isn't reprocessed. This is now and has been done on an industrial scale in Europe and the U.K. for several decades. For some reason the United States, under the guise of non-proliferation, will not permit reprocessing of spent commercial nuclear reactor fuel.

The story in this article isn't news. Everyone knows how to reprocess spent fuel since before the 1960s. What would be actual "news" is the time at which the United States allows the well-proven, industrial-scale reprocessing to be applied to its own reactors.

Even Canada does it. The United States' nuclear energy policy is laughably stupid. It's a shame, really.

Re:It's mostly a USA problem

[Anonymous Coward]

I was going to ask about this when I saw the story... I know nothing about this area but was always told by people who work on nuclear energy issues that the only reason nuclear wastes exist is because of treaties prohibiting the processing of fuel past a certain point to prevent it from being weaponized. I.e., we could solve the problem of nuclear waste by ignoring or eliminating the treaties, but then we increase the difficulty of regulating nuclear weapons. It was always puzzling to me, because it seemed like nuclear waste was more problematic than regulating materials, but I could see how both would be problematic and so never looked into it further. I always wondered if this was some urban legend... I admit I have no excuse in the age of the internet but never bothered to double-check it.

Re:It's mostly a USA problem

[careysub]

It's mostly a United States problem that waste isn't reprocessed. This is now and has been done on an industrial scale in Europe and the U.K. for several decades. For some reason the United States, under the guise of non-proliferation, will not permit reprocessing of spent commercial nuclear reactor fuel.

Nonsense. Any company that wants to open a fuel reprocessing plant can do so, they just need to apply for a license and be willing to pay the bills.

Perhaps you mean that the U.S. government has decided not to run a fuel reprocessing plant at tax payer expense that produces fuel that no one will take unless paid upfront, and few can use anyway? There are no commercial fuel reprocessing plants anywhere in the world because they cannot make money, only spend it.

Having sufficient reactors under construction that could actually consume the reprocessed fuel stream seems to be an essential ingredient here, otherwise you are simply putting plutonium (and cousins) in a smaller pile. The first pile wasn't all that large to begin with. Little is accomplished by separating the actinides until you are ready to burn them.

Re:It's mostly a USA problem

[Anonymous Coward]

See AREVA plant at https://en.wikipedia.org/wiki/COGEMA_La_Hague_site . The french article ends by stating that the site pays more than 20M€ in local tax.

Re:It's mostly a USA problem

[squizzar]

Well seeing as the US government took a huge amount of money from the nuclear generators over the years to fund a waste storage repository (which they are being sued over because of their utter failure to hold up their end of the deal) perhaps they could use that to pay for reprocessing? The electricity producers (and in turn, therefore, consumers) have already paid for it, taxpayers don't need to be involved.

Re:It's mostly a USA problem

[Anonymous Coward]

The NNPT flat out says that the United States cannot reprocess fuel. It's that simple.

Re:It's mostly a USA problem

[careysub]

Yes, do see the AREVA plant. It was built in 1976 by the French government, and its operation was "privatized" by spinning it off into AREVA, which is majority owned by the French government (and alien concept to many Americans), and which provides the funds for the plant's operation. Thus the plant is still owned by the French government.

AREVA is simply a different way for the French government to manage its plant. Consider that the Los Alamos National Laboratory is actually operated by a private limited liability company: Los Alamos National Security, LLC formed by the University of California, Bechtel, Babcock & Wilcox Technical Services, and URS Energy and Construction. Does this make LANL a commercial venture? Hardly. This is no way AREVA is a commercial venture.

Show me a plant built by private funds. You can't.

Re:It's mostly a USA problem

[careysub]

Well seeing as the US government took a huge amount of money from the nuclear generators over the years to fund a waste storage repository (which they are being sued over because of their utter failure to hold up their end of the deal) perhaps they could use that to pay for reprocessing? The electricity producers (and in turn, therefore, consumers) have already paid for it, taxpayers don't need to be involved.

Perhaps those funds could be used for that purpose. But what about the burner reactors to consume the separated actinides? Simply putting the actinides in a smaller pile forever accomplishes nothing.

Re:It's mostly a USA problem

[careysub]

Can't cite an actual clause in the treaty "flat out saying" this can you?

The NNPT flat out gives unlimited permission for activities supporting peaceful nuclear energy - which includes reprocessing:

Article IV
1. Nothing in this Treaty shall be interpreted as affecting the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination

Re:It's mostly a USA problem

[Anonymous Coward]

Well seeing as the US government took a huge amount of money from the nuclear generators over the years to fund a waste storage repository (which they are being sued over because of their utter failure to hold up their end of the deal) perhaps they could use that to pay for reprocessing? The electricity producers (and in turn, therefore, consumers) have already paid for it, taxpayers don't need to be involved.

Hahahahahaha!!! I suppose you also believe Social Security is a "trust fund' with your contributions in it too?
Face it, the money is already spent elsewhere, there is no 'fund', it's just more debt to be printed when/if they decided to build one.

subspace carrier

[Anonymous Coward]

i hope it works. this way way we can invent new technology qith this new energy source and and ransform all earth mass to a single hydrogen atom as 3rd planet orbiting the sun. not aure who will inhabit this this place though.

Perfect fuel for Dirty Bomb

[Taco Cowboy]

option A: moderate toxicity/radioactivity for (hundreds of) thousands of years
option B: EXTREME toxicity/radioactivity for decades

To the militarists option B is a Godsend

Whatever elements that make up the bulk in Option B are perfect for DIRTY BOMB

Re:Perfect fuel for Dirty Bomb

[Anonymous Coward]

Oh no! Not DIRTY BOMB! And you put the words in bold, and all capitals, so now I'm scared and upset.

French did this 30 years ago

[mrbill1234]

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

What is safe?

[trout007]

You are right. The ignorance of many people on the subject of radioactivity is amazing. I don't know why, maybe because nuclear seems magical. But the radiation produced by an isotope is inversely proportional to the half life. People complain about nuclear waste that will be radioactive for a million years. Sure but that stuff is pretty safe because of that long half life it doesn't produce much radiation. It's the short lived isotopes that are really dangerous because of the amount of radiation they put out. Luckily you don't have to keep them long until they decay to safe levels. It's the stuff right in the middle with half lives in the 10-100 year range. They are radioactive enough to be a health concern but also take a long enough time to decay. Of course the type and energy level of the radiation needs to be factored in as well.

Re:What is safe?

[Giant Electronic Bra]

Well, even 10k or 100k yr half-lives are not so good, and even Pu is BAD STUFF in the wrong context. Eat some and you might as well dig your own grave. OTOH its not so hard to handle. Its all messy, and the truth is that for a lot of the really low level stuff the best option would be to just dilute it to oblivion, burn it in some remote place, etc. Most of the low-level waste really is not that bad and the levels are minute.

Nuclear reactors do not "Burn" anything

[Anonymous Coward]

Seriously, Slashdot, you just keep getting worse and worse. You guys probably sit around your conference room table every day wondering among yourselves why the average Slashdot article MAYBE gets 50 comments anymore.

OOOPS FACTOR

[JimSadler]

Maybe I'm really wrong but wasn't a similar idea around during the Carter administration and halted due to potential dangers?

exactly which civilization did you have in mind?

[Anonymous Coward]

> ...which is a tricky commitment for even the most stable civilization

In the context of thousands of years, this sounds like a purely theoretical -- no, a fictional -- civilization.

Reactor burning nuclear waste ?

[GuB-42]

Isn't burning waste what fast breeder reactors do ? They already did this but it didn't make it somehow. Superphénix for example had a few technical issues but still managed to be commercially exploited for a time. If was shut down for political reasons.
The current stand is to use reprocessing and MOX fuel.

Wow

[Anonymous Coward]

We WERE able to do this in the 70s until dumbass pussy Jimmy Carter outlawed this. Now all nuke sites in America have a bunch of waste to deal with instead of reusing the waste and then being left with something not radioactive.

"One man's waste is another man's treasure"

[Anonymous Coward]

Nothing is waste. It is simply not an ideal input for the process that created it. We could be considered the waste product of stellar evolution. If all you cared about was stars, then all this metal stuff (the non-hydrogen and -helium stuff) is just pollution and waste. That's why Black Holes were created (they were originally called Yucca Holes). But I digress.

Hitachi? Whatever

[SIInudeity]

Hitachi had a contract for welding boilers on a South African coal plant. They couldnt even get that right. Delayed the project by 2 years and added a couple of hundred million dollars onto the cost.

Still "a few hundred years"

[Anonymous Coward]

Not really a full solution

eye for an eye

[McFly777]

A bit off-topic, but the eye-for-an-eye statement was not indended as a recommended sentence, but rather as a limitation. It was to keep things from escalating as in, "you injured me therefore I am going to kill you in retrubution." The eye-for-an-eye meant that you could only retaliate to the extent that you were harmed, and no more.

I'd have to look to see where the eye/eye statement first appears in the Bible (I only remember the New Testament refutation of it), but remember that the Hebrews spent quite a bit of time under Babylonian rule. So there was a lot of opportunity for each culture to absorb various aspects of the other.

What we need is a a reactor ...

[Ihlosi]

... that uses any kind of atom as fuels and produces heat and stable iron isotopes, and does so on an acceptable timescale ( Let's call it "minimum binding energy reactor".

We've had this for YEARS NOW

[leereyno]

We've known how to build these reactors for over 20 years now. They're called 2nd generation breeder reactors.

Why don't we have them?

Because the anti-nuclear crazies are able to scream loud enough that the organized incompetence known as government shut it all down.