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Hitachi Developing Reactor That Burns Nuclear Waste

samzenpus posted about a month ago | from the no-waste-zone dept.

Science 200

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.

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Good (3, Insightful)

geekoid (135745) | about a month ago | (#47821289)

Can we get more companies doing these please?

Re:Good (1)

Anonymous Coward | about a month ago | (#47821463)

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.

Re:Good (2)

Applehu Akbar (2968043) | about a month ago | (#47822439)

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.

Re:Good (0)

Anonymous Coward | about a month ago | (#47822757)

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.

Re:Good (3, Insightful)

perpenso (1613749) | about a month ago | (#47821623)

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.

Re:Good (5, Insightful)

newcastlejon (1483695) | about a month ago | (#47822357)

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".

Re:Good (1)

perpenso (1613749) | about a month ago | (#47822547)

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.

Re:Good (1)

calidoscope (312571) | about a month ago | (#47822567)

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

Re:Good (0)

Anonymous Coward | about a month ago | (#47822769)

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

Re:Good (2)

calidoscope (312571) | about a month ago | (#47822557)

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.

Re:Good (1)

Anonymous Coward | about a month ago | (#47822643)

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.

I am the god of hellfire and I bring you (5, Funny)

Anonymous Coward | about a month ago | (#47821301)

Hitachi!

Re:I am the god of hellfire and I bring you (1)

Zynder (2773551) | about a month ago | (#47822321)

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

Already commented on this elsewhere (1, Informative)

AutodidactLabrat (3506801) | about a month ago | (#47821311)

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 (4, Interesting)

geekoid (135745) | about a month ago | (#47821357)

"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 (2)

perpenso (1613749) | about a month ago | (#47821703)

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 (4, Insightful)

brianwski (2401184) | about a month ago | (#47821855)

> 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 (0)

Anonymous Coward | about a month ago | (#47821985)

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 (1)

lisaparratt (752068) | about a month ago | (#47823309)

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

Re:Already commented on this elsewhere (2)

khallow (566160) | about a month ago | (#47822065)

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 (4, Insightful)

ShanghaiBill (739463) | about a month ago | (#47822113)

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 (2)

hidden (135234) | about a month ago | (#47822261)

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 (-1)

Anonymous Coward | about a month ago | (#47822333)

He blatantly made a biblical reference to Noah, on Slashdot- a site devoted to SCIENCE, and you chose THAT thing to bitch about?

Re:Already commented on this elsewhere (4, Informative)

ShanghaiBill (739463) | about a month ago | (#47822419)

He blatantly made a biblical reference to Noah

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

Re:Already commented on this elsewhere (1)

ShanghaiBill (739463) | about a month ago | (#47822379)

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 (1)

careysub (976506) | about a month ago | (#47823105)

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 (2)

khallow (566160) | about a month ago | (#47822683)

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 (2)

careysub (976506) | about a month ago | (#47823231)

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 (1)

Jack Griffin (3459907) | about a month ago | (#47822791)

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 (5, Informative)

careysub (976506) | about a month ago | (#47823225)

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 [utexas.edu] (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 [stfrancis.edu] , before Tohoku (the slightly dated linked list misses the 2007 Niigata tsunami).

Re:Already commented on this elsewhere (5, Informative)

Tailhook (98486) | about a month ago | (#47822103)

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

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 [japantimes.co.jp] 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, [thebulletin.org] which is about the only significant difference between these sites.

TEPCO bean counters. End of story.

Re:Already commented on this elsewhere (1)

LordLimecat (1103839) | about a month ago | (#47822741)

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 (1)

jafac (1449) | about a month ago | (#47822943)

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 (2)

TWX (665546) | about a month ago | (#47821381)

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 (1)

Anonymous Coward | about a month ago | (#47821501)

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 (4, Informative)

perpenso (1613749) | about a month ago | (#47821717)

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 (4, Informative)

Giant Electronic Bra (1229876) | about a month ago | (#47821387)

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 (2, Insightful)

rogoshen1 (2922505) | about a month ago | (#47821483)

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 (0)

Anonymous Coward | about a month ago | (#47821601)

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

We need robust research, not conclusion jumping (0)

Anonymous Coward | about a month ago | (#47821831)

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.

Re:Already commented on this elsewhere (1)

MrKaos (858439) | about a month ago | (#47822111)

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 (1)

Giant Electronic Bra (1229876) | about a month ago | (#47822587)

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 (1)

camperdave (969942) | about a month ago | (#47822615)

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 (0)

Anonymous Coward | about a month ago | (#47822879)

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.

Perfect fuel for Dirty Bomb (2)

Taco Cowboy (5327) | about a month ago | (#47822895)

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:Already commented on this elsewhere (1)

CrimsonAvenger (580665) | about a month ago | (#47821491)

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 (0)

Anonymous Coward | about a month ago | (#47822339)

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 (0)

Anonymous Coward | about a month ago | (#47821557)

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 (5, Interesting)

brambus (3457531) | about a month ago | (#47821515)

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 (4, Informative)

Cyberax (705495) | about a month ago | (#47823083)

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.

Already commented on this elsewhere (0)

Anonymous Coward | about a month ago | (#47821833)

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

Re:Already commented on this elsewhere (1)

careysub (976506) | about a month ago | (#47823087)

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.

First... (1)

Anonymous Coward | about a month ago | (#47821313)

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

Re:First... (1)

gargleblast (683147) | about a month ago | (#47821917)

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

Nucular wands. (1)

fragfoo (2018548) | about a month ago | (#47821339)

This is just so they can build more powerful wands.

No mention of thorium (2)

Tinsoldier314 (3811439) | about a month ago | (#47821403)

Don't LFTRs solve the same problem?

Re:No mention of thorium (5, Informative)

brambus (3457531) | about a month ago | (#47821545)

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 (1)

knapper_tech (813569) | about a month ago | (#47821663)

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

Re:No mention of thorium (4, Informative)

brambus (3457531) | about a month ago | (#47821725)

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 (2)

knapper_tech (813569) | about a month ago | (#47821645)

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 (2)

MrKaos (858439) | about a month ago | (#47822179)

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 (3, Informative)

Cyberax (705495) | about a month ago | (#47821411)

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? (3, Informative)

BringsApples (3418089) | about a month ago | (#47821481)

Try here: new reactor design [gizmag.com] .

First Link is Broken (1)

knapper_tech (813569) | about a month ago | (#47821511)

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

By far not the only design that does this. (4, Informative)

quax (19371) | about a month ago | (#47821533)

By I much prefer inherently safe reactor designs. [wavewatching.net]

Re:By far not the only design that does this. (4, Interesting)

brambus (3457531) | about a month ago | (#47821815)

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. (2)

quax (19371) | about a month ago | (#47821945)

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. (2)

brambus (3457531) | about a month ago | (#47821983)

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. (1)

quax (19371) | about a month ago | (#47822593)

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. (1)

camperdave (969942) | about a month ago | (#47822639)

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. (1)

Cyberax (705495) | about a month ago | (#47823097)

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.

...it can be broken down into near-nothing?! (0)

Anonymous Coward | about a month ago | (#47821549)

...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?! (5, Interesting)

The Grim Reefer (1162755) | about a month ago | (#47822091)

...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 (5, Funny)

Gliscameria (2759171) | about a month ago | (#47821571)

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.

It's a very small problem (5, Interesting)

Anonymous Coward | about a month ago | (#47821925)

>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.

Re:It's a very small problem (3, Insightful)

PPH (736903) | about a month ago | (#47822055)

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 (0)

Anonymous Coward | about a month ago | (#47823315)

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.

Properly processed? (1)

Anonymous Coward | about a month ago | (#47821609)

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 (1)

ArcadeMan (2766669) | about a month ago | (#47821701)

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

Water cooled, TRU burning reactor = BS (4, Informative)

macpacheco (1764378) | about a month ago | (#47821781)

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 (2)

brambus (3457531) | about a month ago | (#47822053)

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.

Nice to see (1)

DaMattster (977781) | about a month ago | (#47821797)

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!

How about protons instead of neutrons? (1)

Albinoman (584294) | about a month ago | (#47822067)

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? (3, Informative)

russotto (537200) | about a month ago | (#47822229)

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? (2)

Albinoman (584294) | about a month ago | (#47822841)

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/... [washington.edu]

Just may be the solution to global warming (2)

iamacat (583406) | about a month ago | (#47822085)

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.

Highly interesting results if true (5, Interesting)

brambus (3457531) | about a month ago | (#47822137)

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 [epri.com] :

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.

They love it (0)

amightywind (691887) | about a month ago | (#47822161)

Slashdot lusers sure do love their crank energy science. Some advice. Invest in gas fracking, the real energy revolution.

Magic wand? (2)

neonleonb (723406) | about a month ago | (#47822207)

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 (0)

Anonymous Coward | about a month ago | (#47822397)

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 (3, Funny)

Tumbleweed (3706) | about a month ago | (#47822447)

Hitachi means 'sunrise'. :)

So when the Canadian wheelchair assassins roll in (0)

Anonymous Coward | about a month ago | (#47822501)

. . . 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. [goodreads.com]

Sorry, but anyone who claims that ... (1)

Ihlosi (895663) | about a month ago | (#47822533)

... 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... [wikipedia.org]

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 ... (0)

Anonymous Coward | about a month ago | (#47822585)

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

The thing I worry about (4, Interesting)

Chas (5144) | about a month ago | (#47822627)

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 (3, Insightful)

kriston (7886) | about a month ago | (#47822709)

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 (0)

Anonymous Coward | about a month ago | (#47823035)

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 (1)

careysub (976506) | about a month ago | (#47823275)

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.

subspace carrier (0)

Anonymous Coward | about a month ago | (#47822869)

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.

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