Fort Calhoun nuclear plant will get series of inspections before restart

[Omaha Steve]

Source: Omaha World Herald

By Kevin Cole

The U.S. Nuclear Regulatory Commission has launched a series of inspections at the Fort Calhoun nuclear plant to examine the facility's restart checklist and evaluate a recent cooling pump issue.

Lara Uselding, a spokeswoman for the NRC, said Monday that inspectors will evaluate a condition involving four main water pumps incorrectly anchored with shorter bolts than required. Uselding said 9-inch bolts have been replaced with 16-inch bolts.

The pumps provide the main cooling water from the Missouri River to the plant, and shorter bolts may have caused the pumps to be inoperable following extreme ground motion such as an earthquake, according to the NRC.

NRC inspectors are reviewing items from the restart checklist that include flooding, fire and the safety culture, she said. About 450 items need to be inspected prior to any restart authorization.

FULL story at link.


Read more: http://www.omaha.com/article/20130128/NEWS/701299991/1685#fort-calhoun-nuclear-plant-will-get-series-of-inspections-before-restart

[sulphurdunn]

1. A friend of mine

who researches thorium reactors told me that the only reason we ever built uranium reactors was to kill two birds with one stone by also providing fissionable material for nuclear weapons. He also says that thorium reactors would have been much, much safer and cost effective. I'd like some input on that from anyone who knows something about it. Thanks.

[bananas]

2. He's wrong on all counts.

The person who maintains the Nuclear Weapon Archive website explained it clearly:

http://science.slashdot.org/comments.pl?sid=1495612&cid=30623708

Wired Article Errors and Omissions (Score:5, Informative)
by careysub (976506) on Saturday January 02 2010, @01:20PM (#30623708)

The Wired Magazine article presents a false picture of the development of nuclear power and leaves out some crucial facts about thorium reactors. A key fact about thorium reactors mentioned no where in the article: you can't build a reactor, load it with thorium alone, and have it work. It will sit there producing no power forever. This because thorium is only the breeding material and is not fissile. To get the reactor to produce power the thorium has to be mixed with plutonium or U-233 bred in some uranium fueled reactor somewhere, or with highly enriched U-235. In other words - the reactor has to be loaded with bomb-usable material and there has to be a lot of it, enough for hundreds of weapons.

This is part of why the whole quasi-conspiratorial story of "why we didn't go with thorium in the first place" is utter nonsense. It was not because "we wanted bombs instead" and were prejudiced against "superior thorium", it is because only if you have an established nuclear industry cranking out materials usable in bombs by the thousands can you build these reactors in the first place. Either you must have natural/low enriched uranium reactors to produce plutonium, or you need large amounts of highly enriched uranium (prime bomb material) to load into thorium breeders.

Also unacknowledged is that the particular type of reactor being promoted, the molten fluoride salt reactor, was and is a complex technology that requires substantial additional development. Only one single reactor of this kind was ever built, and it was an 8 megawatt (thermal) materials test reactor, not a power reactor. We are looking at many years of additional development before construction can start on a prototype full scale power reactor. I agree that this technology should be further pursued, and it may turn out more successful that plutonium breeders (no successful power plants have been built, just several failures) but it is by no means guaranteed.

Hyman Rickover, by the way, was interested in light water uranium fueled reactors because they are a good technology for powering submarines, not because they produce plutonium (they are lousy plutonium producers, the yield is low and the material produced has terrible properties for bombs).

Check out the 2005 IAEA survey document ( http://www.energyfromthorium.com/pdf/IAEA-TECDOC-1450.pdf ) for a good summary of the thorium technology options and prospects.

Also, that 8 megawatt "thorium" reactor ran on uranium, not thorium:

http://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment

The Molten-Salt Reactor Experiment (MSRE) was an experimental molten-salt nuclear reactor at the Oak Ridge National Laboratory (ORNL) researching this technology through the 1960s; constructed by 1964, it went critical in 1965 and was operated until 1969.

The MSRE was a 7.4 MWth test reactor simulating the neutronic "kernel" of a type of inherently safe epithermal thorium breeder reactor called the Liquid fluoride thorium reactor. It primarily used two fuels: first uranium-235 and later uranium-233. The last, 233UF4 was the result of breeding from thorium in other reactors. Since this was an engineering test, the large, expensive breeding blanket of thorium salt was omitted in favor of neutron measurements.

[sulphurdunn]

4. Thanks for the info

[bananas]

3. Nature recently ran an article debunking some of the hype regarding thorium's proliferation risks.

Posted in the Science forum in December:

http://www.democraticunderground.com/122813650

Fri Dec 21, 2012, 08:49 AM
bananas (19,350 posts)

Proliferation Warnings On Nuclear 'Wonder-Fuel', Thorium

There's been a lot of anti-science hype about Thorium as a nuclear fuel.

Nature recently ran an article debunking some of the hype regarding it's proliferation risks.

Here are two news stories about it, the second one has some good comments by Thierry Dujardin, deputy director for science and development of the Organisation for Economic Co-operation and Development’s Nuclear Energy Agency.

http://www.sciencedaily.com/releases/2012/12/121205132246.htm

Proliferation Warnings On Nuclear 'Wonder-Fuel', Thorium

Dec. 5, 2012 — Thorium is being touted as an ideal fuel for a new generation of nuclear power plants, but in a piece in this week's Nature, researchers suggest it may not be as benign as portrayed.

The element thorium, which many regard as a potential nuclear "wonder-fuel," could be a greater proliferation threat than previously thought, scientists have warned.

<snip>

http://www.popularmechanics.com/science/energy/nuclear/is-the-superfuel-thorium-risker-than-we-thought-14821644

Is the "Superfuel" Thorium Risker Than We Thought?

A new study in Nature says that using thorium as a nuclear fuel has a higher risk for proliferation into weapons than scientists had believed.

By Phil McKenna

December 5, 2012 2:05 PM

Imagine a cheap, plentiful source of energy that could provide safe, emissions-free power for hundreds of years without refueling and without any risk of nuclear proliferation. The fuel is thorium, and it has been trumpeted by proponents as a "superfuel" that eludes many of the pitfalls of today’s nuclear energy. But now, as a number of countries including China, India, and the United States explore the potential use of thorium for nuclear power, researchers say one of the biggest claims made about the fuel—its proliferation resistance—doesn’t add up.

<snip>

However, Dujardin says, a number of advanced reactor designs, including molten salt reactors, provide similar benefits and can use existing uranium-based fuel. And for cost reasons alone, Dujardin says it may be better to continue developing next-generation reactor designs using existing uranium fuel technology.

"When a technology is in some difficulty, and nuclear technology has been shocked by the Fukushima accident in Japan, people search for a magic solution, but there is no silver bullet," he says. "The difference in the state of development of thorium versus other sources of fuel is so vast and the cost of developing the technology is so high, it’s really questionable today whether it’s worthwhile to spend a lot of money on the development of thorium."

<snip>