Politics, Religion, Science, Culture and Humanities > Science, Culture, & Humanities

Nuclear Power

(1/41) > >>

Crafty_Dog:
All:

My default bias on nuclear power tends to be strongly negative.  I worry about what to do with by-products both for concern over accidents and for concern over the risks of theft; it being a source of unsound countries building nuclear bombs; catastrophes such as Chernoble; and nuclear reactors being targets to terrorist attack-- e.g. what if Flight 93 had its target the reactor at Three Mile Island.  One screw-up could screw up a lot of mother earth for a very long time. 

I distrust the experts.  Here in California, the Diablo Canyon reactor was built on an earthquake fault line. :-o  Something like that does not inspire confidence to say the least.

That said, with the strong pressures to move beyond petroleum, the nuclear question is being presented again and of course advocates are proffering what they believe to be solutions to concerns.

Marc
================

Monday, November 20, 2006 
 
Barron's
EDITORIAL COMMENTARY   
Needed for Nuclear Power
Fuel recycling mitigates waste worries and is key to new plant construction
By WILLIAM R. STRATTON and DONALD F. PETERSON
 
BETWEEN 1965 AND 1985, the U.S. constructed 110 nuclear electric-power reactors and is now operating 103 atomic plants that provide 20% of the nation's electric-power demand. Their operating record in recent years has been little short of phenomenal. Because of their safety and operating records, their permits or licenses are being extended from 40 to 60 years.

A number of electric utilities are on the verge of submitting applications to the Nuclear Regulatory Commission for a combined construction and operating license. The proposed reactors will be of an improved and simplified design, pre-approved, more amenable to maintenance and operation than the first-generation reactors designed before 1980. All will be of a size to provide 1,000 to 1,500 megawatts, day and night, wind or no wind, rain or snow. Some studies estimate that more than 1,000 additional power stations of this size will be needed in the next half-century. After reviewing seven comprehensive studies, the World Nuclear Association stated flatly in December 2005 that nuclear power is competitive now.

This is good news. But there is still a problem created 30 years ago when President Jimmy Carter forbade the reprocessing of spent nuclear fuel, establishing the once-through fuel cycle and effectively killing active development of commercial nuclear power. This wrong-headed decision was prompted by concern about the spread of nuclear weapons. Carter expected that the rest of the world would follow our lead, but no other countries have so limited their application of nuclear technology.

Supply and Storage

Carter's decision did create two other problems, neither foreseen by his administration nor fully solved, even after 30 years. The first is the problem of supply. It may be that insufficient uranium ore exists to fuel the nuclear-power industry for an extended period. The thermal neutron light-water reactor industry is sustained by the uranium-235 isotope -- only 0.7% of naturally occurring uranium. This must be enriched to about 3% U-235 to be suitable for power-plant fuel. Some studies suggest that there are limited quantities of uranium ore, others are more optimistic. The availability of adequate uranium to sustain the once-through cycle is still an open question.

The second and more significant issue is that of storing or disposing of spent fuel. This may be a red herring, but it has a very powerful odor. Many people believe that disposing of spent fuel is a show-stopper.

At the present rate of production, there will be enough spent fuel waiting in 2010 to fill the Yucca Mountain repository in Nevada, which has a capacity of 70,000 metric tons. Of course, the squabbling over regulations for storage at Yucca Mountain continues with no license in sight. The previous requirement for 10,000 years of safe storage recently has escalated to millions of years.

If a new surge of power-plant construction is about to begin, the spent-fuel problem must be solved. The rising demand for electricity suggests that the rate of plant construction will surpass that of the 1970s by a large margin -- depending in part on the congressional perception of global warming. New Yucca Mountain-type storage sites will be required, and we will see intense bureaucratic infighting over safety and security needs.

It's not often understood that the protracted times for the safe storage of spent fuel result from the presence of "transuranics" in it, not from the direct products of uranium fission. Transuranics are the isotopes that build up in the fuel when a uranium atom captures one or more neutrons without fission. Some of these decay into different elements: For example, plutonium-241 decays to americium-241, which then, too, can capture neutrons. Several of these isotopes have lifetimes in the thousands and tens of thousands of years. Some generate enough heat to be a problem.

Beyond the not-in-my-back-yard syndrome, transuranics are the reasons for the difficulties with storage in a repository like Yucca Mountain.

Fortunately, solutions to the waste problem are under development in the U.S., France, Great Britain, Russia and Japan. It's overdue, since recycling of fuel and waste was the intent of the pioneering engineers of nuclear power plants back in the 1950s.

A recycling process in use abroad comprises about three chemical steps and permits some separation of uranium, plutonium, other transuranics and fission products. The volumes of contaminated liquid waste is drastically reduced. The plutonium from this process can be used in thermal neutron reactors, but for only another two cycles because the higher isotopes of plutonium stop the fission process.

Another method still being developed is called pyrometallurgical recycling or electro-refining. This removes the fission products from the uranium, plutonium and other transuranics. Waste volume would be small, consisting almost entirely of fission products with much shorter half-lives than transuranics, so the necessary storage times would be reduced from thousands to hundreds of years. The remainder, consisting of plutonium mixed with other transuranics, is an unattractive target for theft but perfectly acceptable as fuel for fast-neutron breeder reactors. Early estimates suggest it is a much less expensive process to separate the several parts of spent fuel.

U.S. nuclear engineers have extensive experience with breeder reactors, which are the necessary final step in this development of modern nuclear-reactor technology using a closed fuel cycle. Among the initial reactors developed after World War II, Experimental Breeder Reactor No. 1 was the first in the world to generate electricity from nuclear energy; the event took place in Idaho in December 1951. Its successor, called EBR-2, operated successfully for 30 years from the early 1960s, generating more than 60 megawatts of electricity and serving as a test bed for experiments at the same time.

Fast-neutron breeder reactors can use all the transuranics and fission them to generate electricity. These reactors can be designed to produce excess plutonium from U-238 for additional fuel, or burn plutonium to generate electricity. They burn or transmute the troublesome part of the spent fuel, while producing electric power and more plutonium for other fast reactors, or thermal neutron reactors using mixed-oxide fuel.

Prototype Time

Various designs of this reactor concept have been constructed and operated successfully in the U.S. and other countries. Prototype plants have existed in France since 1974, in Russia since 1981, and Japan plans to incorporate the closed fuel cycle with breeder reactors systematically in this century. Both India and China have plans for constructing breeder reactors.

The technology now exists for recycling spent reactor fuel, and fast neutron sodium-cooled reactors have been operated for many years. The critical components of the closed fuel cycle are ready for prototype operations, preferably an integrated demonstration financed by a consortium of electric utilities or the Department of Energy.

This is an expensive but necessary investment for the future. Yucca Mountain storage expense could be reduced to a small fraction of present costs, and mandatory storage time reduced to a few hundred years.

The closed cycle, using enriched uranium for fuel in light-water reactors, recycling of spent fuel through an electrochemical process, and using the recovered plutonium and other transuranics as fuel in a breeder reactor, is complete. It's not a simple process, but it's essential to assure ample energy for the indefinite future. It will be expensive to start, but there are no viable alternatives. The time to expand nuclear-power generation is now.


--------------------------------------------------------------------------------

WILLIAM R. STRATTON and DONALD F. PETERSON are nuclear scientists, retired from Los Alamos National Laboratory. They are members of the Los Alamos Education Group, a non-profit organization advocating increased use and development of nuclear energy.

 

Crafty_Dog:
NUKE CHIEF FIRED: Linton Brooks, the chief of the country's nuclear-weapons program,
was fired yesterday because of security breakdowns at the Los Alamos, N.M., laboratory and other facilities.

LBN news

Crafty_Dog:
Although it is the LA Times, this makes sense to me.

========================================

Yucca Mountain on hold
The Obama administration is prudent to put the brakes on the nuclear waste repository in Nevada.
March 19, 2009


Senate Majority Leader Harry Reid (D-Nev.) has been called many things during his 22-year Senate career, but the name that sticks when the issue of nuclear power comes up is "NIMBY." That's because Reid has fought tirelessly to block construction of a national nuclear waste repository at Yucca Mountain in his home state. There's a funny thing about his critics, though: Not one of them has ever suggested shipping the country's hazardous radioactive waste to his or her own state or district instead of Nevada.

The usual bleating about Reid's obstructionism and Nevadans' paranoia arose after the release of President Obama's proposed budget, which trims funding for the Yucca Mountain project to the minimum needed to keep the regulatory process involved in its construction alive -- a strong signal that there will be no further work done on the repository during Obama's term in office. Energy Secretary Steven Chu said the administration is working on an alternative program that involves multiple interim and long-term waste storage facilities around the country.


Ads by Google
HUD Homes - $10,000

Buy HUD Home at huge 50% savings. Pay $1 to get listings in your area

www.HUDforeclosed.com

Nevada Corp Q&A Free Book

Strategies & secrets. 15 yrs. exp. Get "The Nevada Edge". A $20 value.

www.nchinc.com

Incorporate in Nevada

$31 Plus State Fees Is All It Takes Apply Online In Minutes. LLCs too.

www.SmallBiz.com
When it comes to highly radioactive nuclear waste, pretty much everybody is a NIMBY. Setting aside the factthat scientists have yet to develop the technology to safely store this waste for the thousands of years it takes to decay, there's the fact that it has to be transported to the disposal site -- mostly by train -- creating the opportunity for spills. Even if the nuclear dump isn't in your backyard, the train tracks might be, and the closer you live to the center of it all, the greater the danger. Little wonder that Nevadans aren't excited by the prospect of a glow-in-the-dark desert.

The depressing thing about Yucca Mountain is that for all its flaws, including the discovery that water flows through the mountain faster than previously thought and thus could contaminate nearby areas, it probably still represents the safest place in the country for a nuclear repository. Not only is seismic activity in the rangeminimal, but the mountain is in a remote and desolate region at the edge of a site used in the 1950s for atomic testing. If we can't dump the waste in a nuclear test zone, where can we? That, in a nutshell, is the problem with nuclear power.

Pro-nuclear activists, whose ranks are growing as the nation looks for non-carbon-emitting sources of energy, needn't fret too much about Obama's proposal, which tables but doesn't end the debate about Yucca Mountain. Yet the move probably would delay some pending applications for construction of nuclear plants, and may even stop some. That's all for the good. Nuclear power is much too risky and expensive to be seen as a reasonable solution to climate change.

ccp:
There was a recent segment on cable about the disposal of nuclear waste in salt caverns and how the salt is nearly a perfect way to encircle and keep  isolated the waste.
The deep underground caverns (~2,000 feet I think) eventuall get literally encased in the salt which protects against water.
However, it would take 250,000 years for the stuff to decay and no one could say what the risk to future and interim generations would be so far in advance (if the human race is still around by then anyway).

As far as transporting the stuff to these natural salt "containers" that is another homeland defense story.
As for what is going to happen thousands of years from now I won't lose sleep over that.

ccp:
http://www.nei.org/keyissues/nuclearwastedisposal/

***NEI: Nuclear Energy Institute Home Member Login Contact Us Search 
 l
Most used fuel from nuclear power plants is stored in steel-lined concrete pools filled with water, like this one above, or in airtight steel or concrete-and-steel containers.
Used Nuclear Fuel and Low-Level Waste
Used nuclear fuel is a solid material safely stored at nuclear plant sites. This storage is only temporary—one component of an integrated used fuel management system that addresses all facets of storing, recycling and disposal.
Integrated Used Fuel Management
Under an integrated management approach, used nuclear fuel will remain stored at nuclear power plants in the near term. Eventually, the government will recycle it and place the unusable end product in a repository at Yucca Mountain, Nev.

Storage of Used Nuclear Fuel
Currently, used nuclear fuel is stored at the nation's nuclear power plants in steel-lined, concrete vaults filled with water or in massive, airtight steel or concrete-and-steel canisters.

Recycling Used Nuclear Fuel
The federal government plans to develop advanced recycling technologies to take full advantage of the vast amount of energy in the used fuel and reduce the amount and toxicity of byproducts requiring disposal.

Yucca Mountain
In 2002, Congress approved Yucca Mountain, Nev., a remote desert location, as the site for a centralized deep geologic repository for used nuclear fuel and other high-level radioactive waste.

Transportation
The U.S. Department of Energy will transport used nuclear fuel to the repository by rail and road, inside massive, sealed containers that have undergone safety and durability testing.

Low-Level Radioactive Waste
Low-level waste is a byproduct of the beneficial uses of a wide range of radioactive materials. These include electricity generation, medical diagnosis and treatment, and various other medical processes.

Navigation

[0] Message Index

[#] Next page