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Old 2008-07-15, 23:45   #67
FactorEyes
 
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Quote:
Originally Posted by xilman View Post
Even if the tritium is vented (and I'm not suggesting it should be), it's not much of a problem. The half-life is short and the electrons come off at very low energy.
This reminds me of the issue of uranium belched from coal-burning power plants. I recall a figure in tons that is greater the depleted uranium used in weapons in both Iraq wars, and in only one calendar year. This is, of course, non-depleted uranium we speak of, which is worse than depleted uranium. From a Scientific American article:

Quote:
Over the past few decades, however, a series of studies has called these stereotypes into question. Among the surprising conclusions: the waste produced by coal plants is actually more radioactive than that generated by their nuclear counterparts. In fact, fly ash—a by-product from burning coal for power—contains up to 100 times more radiation than nuclear waste.

At issue is coal's content of uranium and thorium, both radioactive elements. They occur in such trace amounts in natural, or "whole," coal that they aren't a problem. But when coal is burned into fly ash, uranium and thorium are concentrated at up to 10 times their original levels.

Fly ash uranium sometimes leaches into the soil and water surrounding a coal plant, affecting cropland and, in turn, food. People living within a "stack shadow"—the area within a half- to one-mile (0.8- to 1.6-kilometer) radius of a coal plant's smokestacks—might then ingest small amounts of radiation. Fly ash is also disposed of in landfills and abandoned mines and quarries, posing a potential risk to people living around those areas.

In a 1978 paper for Science, J. P. McBride at Oak Ridge National Laboratory (ORNL) and his colleagues looked at the uranium and thorium content of fly ash from coal-fired power plants in Tennessee and Alabama. To answer the question of just how harmful leaching could be, the scientists estimated radiation exposure around the coal plants and compared it with exposure levels around boiling-water reactor and pressurized-water nuclear power plants.

The result: estimated radiation doses ingested by people living near the coal plants were equal to or higher than doses for people living around the nuclear facilities. At one extreme, the scientists estimated fly ash radiation in individuals' bones at around 18 millirems (thousandths of a rem, a unit for measuring doses of ionizing radiation) a year. Doses for the two nuclear plants, by contrast, ranged from between three and six millirems for the same period. And when all food was grown in the area, radiation doses were 50 to 200 percent higher around the coal plants.
I harbor some suspicions of nuclear power, including even fusion -- if you must use remote handling for one year when cleaning up after several shots at a fusion reactor, you are looking at an industry in need of good oversight. However, I think we tend to overlook how truly nasty coal is. Any current means of producing significant quantities of energy requires a mess at some stage. A friend went to watch the coal trains rolling out of the Powder River Basin recently, and he came back a changed man: always one to make fun of environmentalists, he now turns off most of the lights in his home. He was appalled at the scale of the mining out there.

One plant in Georgia (Schering?) requires 35 coal trains remain constantly in motion to feed its input stocks. If you have ever stood by as a 110-car coal drag runs past, you know that's serious diesel fuel, and an immense amount of coal.
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Old 2008-07-17, 12:48   #68
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Quote:
Originally Posted by FactorEyes View Post
This reminds me of the issue of uranium belched from coal-burning power plants. I recall a figure in tons that is greater the depleted uranium used in weapons in both Iraq wars, and in only one calendar year. This is, of course, non-depleted uranium we speak of, which is worse than depleted uranium. From a Scientific American article:



I harbor some suspicions of nuclear power, including even fusion -- if you must use remote handling for one year when cleaning up after several shots at a fusion reactor, you are looking at an industry in need of good oversight. However, I think we tend to overlook how truly nasty coal is. Any current means of producing significant quantities of energy requires a mess at some stage. A friend went to watch the coal trains rolling out of the Powder River Basin recently, and he came back a changed man: always one to make fun of environmentalists, he now turns off most of the lights in his home. He was appalled at the scale of the mining out there.

One plant in Georgia (Schering?) requires 35 coal trains remain constantly in motion to feed its input stocks. If you have ever stood by as a 110-car coal drag runs past, you know that's serious diesel fuel, and an immense amount of coal.
I found some decent reference information on coal fly ash, its' radioactive element concentration and vulnerability to acid leaching that I included earlier in this thread (and gratuitously include again now):
Quote:
Originally Posted by only_human View Post
Reading this thread, on balance it looks like coal energy production is not given nearly the same scrutiny for environmental and even strategic nuclear risk factors that nuclear energy production receives. As for radioactivity of coal fly-ash I found this to be helpful:
Google Answers Q: Nuclear radiation per MMBtu for coal plants
This led to these interesting sources of additional information:
Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance
Coal Combustion: Nuclear Resource or Danger
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Old 2008-10-10, 08:22   #69
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Nuclear energy remains on my radar of issues. I bumped this thread today to include this tidbit I stumbled across: Time-out: NRC delays decision on Italian waste proposal
Quote:
Article Last Updated: 10/07/2008 06:02:54 PM MDT

The clock was ticking on a disposal proposal that would bring 1,600 tons of foreign radioactive waste to EnergySolutions' dump in Tooele County. Officials at the Nuclear Regulatory Commission were set to rule on the company's request to import low-level waste from Italy's nuclear power industry.
And it didn't look good for the home team - the 2.5 million Utahns who stand to gain nothing except an unwanted distinction: home of the world's dumping ground. Because federal regulations require the NRC to rule solely on the safety of the proposal and without regard to the origin of the waste, the license likely would have been approved.
Then, as time was about to expire, the NRC wisely called a time-out. The agency announced Monday that it will hold the license request "in abeyance" until a federal judge determines if the Northwest Interstate Compact has the authority to reject the proposal.
As I have stated before, I remain concerned about nuclear waste disposal. That is, almost in entirety, my objection to nuclear energy. Since nuclear energy seems to be quite useful and doesn't have a carbon footprint, it is my profound desire to see disposal issues addressed. Anything else is a cart in front of the horse situation.

I notice that the NRC is in backpedal mode on timeframes and appears to be upgrading the merit of "spent fuel storage in pools and dry casks" NRC SEEKS PUBLIC COMMENT ON PROPOSED REVISIONS
TO ITS WASTE CONFIDENCE DECISION
Quote:
The Nuclear Regulatory Commission is seeking public comment on proposed revisions to its waste confidence findings, in particular whether the findings should continue to include a timeframe for the availability of a repository for high-level nuclear waste disposal.

The proposed revisions, to be published and discussed in two separate notices tomorrow (Oct. 9) in the Federal Register, are intended to support the agency’s reviews of license applications for new commercial power reactors by resolving appropriate issues generically in rulemaking.

The waste confidence findings were first issued in 1984, subsequently revised in 1990, and reaffirmed in 1999. They state the Commission’s confidence that a geologic repository would be available sometime in the first quarter of the 21st century and that spent nuclear fuel can be safely stored without significant environmental impacts for at least 30 years beyond the licensed operation of a reactor, including the term of a renewed license. These findings are codified in NRC regulations at 10 CFR 51.23(a).

The proposed revisions would predict that repository capacity will be available within 50 to 60 years beyond the licensed operation of all reactors, and that spent fuel generated in any reactor can be safely stored without significant environmental impact for at least 60 years beyond the licensed operation of the reactor.

The agency is also seeking public comment on whether a timeframe for the availability of a repository should be included at all.

Eliminating the 2025 timeframe is not intended to signal a lack of confidence that a repository will be available by that date. However, the NRC recognizes that a repository can only be available by that date if the agency ultimately approves the Department of Energy’s application to construct a repository at Yucca Mountain, Nev. That decision must await the results of the staff’s technical review and the outcome of an NRC licensing proceeding on the application. The application was submitted June 3 and formally docketed on Sept. 8.

The Commission does not believe the existence of the 2025 date undermines its oft-stated commitment to be an impartial adjudicator of the Yucca Mountain application. However, the agency believes that deleting this date will remove even an appearance of prejudgment in a licensing proceeding for Yucca Mountain.

Revising its findings on the period for safe storage of spent fuel reflects the NRC’s confidence in the safety and security of spent fuel storage in pools and dry casks. This confidence is bolstered by operational experience over the past two decades, as well as extensive security assessments performed by the NRC and security enhancements ordered by the agency in the aftermath of the Sept. 11, 2001, terrorist attacks.
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Old 2008-11-15, 22:41   #70
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Default Hyperion Mini Nuclear Power Plants may be real.

Crow-eating time! Yum! Yum!

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Originally Posted by cheesehead View Post
Jwb52z, I stand by everything I said about www.nextenergynews.com. Its two supposed descriptions of small nuclear power devices are just hoakum and bunkum.
I was careless there, painting both the Toshiba and Hyperion devices with the same brush without considering that all the specific criticisms I'd made had been about the Toshiba description only. As I review what I wrote, it looks like I never pointed out any flaw in the Hyperion description, but just presumed that because both were featured at about the same time on the same site, the Hyperion device must also be unlikely.

(My opinion of www.nextenergynews.com is still low because of its publication of the Toshiba item.)

Now, there's news about the Hyperion devices, from a more reliable source.

http://www.physorg.com/news145561984.html

"Mini Nuclear Power Plants Could Power 20,000 Homes (Update)"

Quote:
(PhysOrg.com) -- Underground nuclear power plants no bigger than a hot tub may soon provide electricity for communities around the world. Measuring about 1.5 meters across, the mini reactors can each power about 20,000 homes. (Please see below for an update)

The small energy modules were originally designed by Otis "Pete" Peterson and other scientists at Los Alamos National Laboratory in New Mexico. Now, the technology is being commercially developed by Hyperion Power Generation, which recently announced that it has taken its first orders and plans to start mass production within five years.

"Our goal is to generate electricity for 10 cents a watt anywhere in the world," said John Deal, CEO of Hyperion. "[The nuclear plants] will cost approximately $25 million each. For a community with 10,000 households, that is a very affordable $2,500 per home."

Because of their small size, the mini power plants can be assembled relatively quickly and transported by truck, rail or ship to remote locations, even places that currently do not have electricity. The power plants provide an alternative to current nuclear plants, which are large, expensive, and take about 10 years to build. Also, large-scale power plants don´t fit the needs of small populations or areas without available land. Hyperion´s modules can be connected together to provide energy for larger populations, as well.

In addition, the Hyperion modules have no moving parts to wear down, and never need to be opened on site. Even if opened, the small amount of enclosed fuel would immediately cool, alleviating safety concerns. "It is impossible for the module to go supercritical, ´melt down,´ or create any type of emergency situation," the company states on its Web site. Because the Hyperion plants would be buried underground and guarded by a security detail, the company explains that they´ll be out of sight and safe from illegitimate uses. Further, the material inside wouldn´t be appropriate for proliferation purposes.

"You would need nation-state resources in order to enrich our uranium," Deal said. "Temperature-wise it´s too hot to handle. It would be like stealing a barbecue with your bare hands."

The reactors need to be refueled about every seven to ten years. After five years of generating power, Hyperion says that the module produces a total waste of about the size of a softball, which could be a candidate for fuel recycling.

Hyperion now has more than 100 orders for its modules, mostly from the oil and electricity industries. The first order came from a Czech infrastructure company called TES, which specializes in water plants and power plants. TES ordered six modules and optioned another 12, with the first planned to be located in Romania.

Hyperion plans to build three manufacturing plants, with the goal of producing 4,000 mini nuclear modules between 2013 and 2023. Next year, the company will submit an application to build the modules to the Nuclear Regulatory Commission.

While acknowledging that the commercial development of mini nuclear plants is a lofty goal, Hyperion believes that the potential benefits of the technology make the effort well worthwhile. Along with bringing electricity to remote locations, the Hyperion modules could also be used to provide clean water for the 25% of the world´s population that currently does not have access to clean water. The modules can provide power to pump, clean, and process water, which in turn can help decrease disease, poverty, and social unrest.

Update (November 12, 2008): The Nuclear Regulatory Commission (NRC) contacted PhysOrg.com to state that the NRC has no plans to review the Hyperion design in the near future, although the NRC and Hyperion have had preliminary talks. Because the Hyperion design is unique, the NRC expects that it will take significant time to ensure safety requirements. In a response to a letter from October 2008, the NRC stated:

“Hyperion Power Generation is in the early stages of development of this design, and very little testing information is available for this design concept. Hyperion Power Generation has indicated that it will submit technical reports to support a pre-application review in late FY 2009. The NRC cannot engage in any meaningful, formal technical interaction with the potential applicant until we receive those reports. Because of the very limited amount of test data and lack of operating experience available for a uranium hydride reactor, the NRC staff anticipates that a licensing review would involve significant technical, safety, and licensing policy issues.”

More information: www.hyperionpowergeneration.com

via: The Guardian

Last fiddled with by cheesehead on 2008-11-15 at 22:51
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Old 2009-04-23, 21:35   #71
only_human
 
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Quote:
Originally Posted by cheesehead View Post
Crow-eating time! Yum! Yum!

I was careless there, painting both the Toshiba and Hyperion devices with the same brush without considering that all the specific criticisms I'd made had been about the Toshiba description only. As I review what I wrote, it looks like I never pointed out any flaw in the Hyperion description, but just presumed that because both were featured at about the same time on the same site, the Hyperion device must also be unlikely.

(My opinion of www.nextenergynews.com is still low because of its publication of the Toshiba item.)

Now, there's news about the Hyperion devices, from a more reliable source.

http://www.physorg.com/news145561984.html

"Mini Nuclear Power Plants Could Power 20,000 Homes (Update)"
The NRC seems to be looking forward to smaller and more flexible Nuclear Plant licensing options:
NRC SEEKS COMMENT ON PROPOSAL TO ESTABLISH A VARIABLE
ANNUAL FEE STRUCTURE FOR NUCLEAR POWER REACTORS
Quote:
The NRC has determined that the current single annual fee structure for nuclear power reactors should be reviewed in light of the potential for future licensing of small and medium sized nuclear reactors, some of which may not be used to generate electric power, and some of which may be used and licensed in configurations of up to 20 reactors (modules). Although issuance of a license for a small or medium sized reactor which triggers imposition of fees may be several years in the future, this proposal invites early input from interested stakeholders and the public on the issues relevant to establish a variable annual fee structure for these reactors.
On another note, an interesting discussion on Coal Fly-Ash exists in this thread. This has been drawing my attention and I am reluctantly being persuaded that the environmental consequences and handling of current coal powered energy production is sloppy and dirty and deserves more attention than my current and ongoing concerns about nuclear waste storage and disposal. More on this later -- I wish to organize my thoughts a bit.

Not only is coal fly ash used in manufacture of the recent spate of bad Chinese drywall, but web info indicates that it is used in American drywall too (sources are not very specific about details but say that it is a more refined product -- for whatever good that means). As info in this thread indicates, many heavier elements become somewhat concentrated in fly ash. Using the material in cinder blocks or concrete seems fine but using it in drywall that may be placed in unventilated basements, etc. in close proximity to children without any caveats seems a bad idea.

Here is a recent fly ash spill:
Tennessee Ash Flood Larger Than Initial Estimate - NYTimes.com

Last fiddled with by only_human on 2009-04-23 at 21:45
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Old 2009-04-24, 04:42   #72
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Quote:
Originally Posted by only_human View Post
NRC SEEKS COMMENT ON PROPOSAL TO ESTABLISH A VARIABLE
ANNUAL FEE STRUCTURE FOR NUCLEAR POWER REACTORS
Quote:
small and medium sized nuclear reactors, some of which may not be used to generate electric power,
What are those others going to be used for, if not to generate electric power?

Water heaters? Hot-air furnaces? All-season barbeque grills?

Microwave oven substitute, still allowing one to "nuke" food?

Blow-dryers? Before-you-commute-to-work windshield defrosters?

Popcorn poppers? DIY radiation therapy? Heated sidewalks?

Fruit leather maker? Lambeau Field tundra-defroster?

Lambeau Field spectator seatwarming? Engine block heaters?

Tanning? Hot-air balloon fillers? Boot warmers?

A nice warm place for the cat to snuggle up to? DIY food irradiation?

Za(http://www.bartleby.com/61/3/Z0000350.html) reheater?

(Hmmm... I seem to be answering my own question.)

Last fiddled with by cheesehead on 2009-04-24 at 05:16
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Old 2009-04-24, 06:41   #73
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Quote:
Originally Posted by cheesehead View Post
What are those others going to be used for, if not to generate electric power?[...]
Interesting isn't it?
Maybe:
  • Large/industrial scale food irradiation and toxic or biological waste decomposition and sterilization
  • Transmutation and/or re-use of radioactive waste in some future administration
  • Early stage pump for some energy weapon
  • Fast access to very short lived isotopes for specialized purposes
  • Neutron source for spectroscopy, explosives detection, standards/calibration
My vote is actually that, for once, they are thinking ahead and trying to put some flexibility into the bureaucracy. Stranger things have happened.

Last fiddled with by only_human on 2009-04-24 at 07:39 Reason: added neutron source speculation (if talking through hat, speak even louder)
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Old 2009-04-24, 12:08   #74
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Neutron source for spectroscopy, explosives detection, standards/calibration
LOL! I could just see them walk into a nuclear plant with a possible bomb. :p
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Old 2009-04-24, 12:57   #75
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LOL! I could just see them walk into a nuclear plant with a possible bomb. :p
Scenario: create radioactive neutron source (easy enough,:standard spallation sources have been known for decades). Take the source away from the plant to, say, docks or airport. Shine the neutrons through cargo and/or baggage. Pick up the gammas and excess neutrons produced by neutron-catalysed fission events. Divert any weapons-capable material before it has chance to be built into weapons.

That's just one means of using a neutron source to detect explosives..


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Old 2009-04-24, 13:16   #76
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Cargo and baggage disconcertingly often turn out to have people in them; I'm not at all sure whether the neutron fluxes required to detect that there are four six-ounce lumps of U235 in a containerload of stainless-steel swarf being shipped off for recycling would be low enough not to pose a serious health threat to a containerload of unlabelled Azeri immigrants.
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Old 2009-04-24, 13:17   #77
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Quote:
Originally Posted by cheesehead View Post
What are those others going to be used for, if not to generate electric power?

Water heaters? Hot-air furnaces? All-season barbeque grills?
I think a serious application (albeit proposed at the height of the oil boom) was to generate superheated steam for getting oil out of oil sands without having to burn prodigious amounts of natural gas first.

Medical isotopes are also handy, and are quite commonly produced in very low-power reactors at the moment.
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