Stories tagged nuclear

Jul
13
2013

Less than one millisecond after detonation: Rapatronic camera image by U.S. Air Force 1352nd Photographic Group, Lookout Mountain Station
Less than one millisecond after detonation: Rapatronic camera image by U.S. Air Force 1352nd Photographic Group, Lookout Mountain StationCourtesy Public domain via Wikipedia
We've all seen images and films of atomic bomb tests performed by the US government during the mid-20th Century: typically a brilliant flash of light followed rapidly by a mushroom cloud expanding outward and high into the sky. But that's not the only images to come out of the Atomic Age. Scientists were eager to gather as much information as they could about every aspect of fission and fusion, and used several means to glean as much as they could from those thermonuclear tests. The mechanical shutters in conventional cameras just weren't fast enough to photograph the very early moments of an atomic blast which occurred in a matter of nano-seconds. So scientists devised the rapatronic camera, an imaging devise that used three polarized lenses and a Kerr cell to capture the earliest moments of a nuclear reaction. Two of the polarized lenses were turned 90 degrees to each other with a third polarized lens turned at the diagonal and sandwiched between them. A Kerr cell is made up of liquid-suspended electrodes and rotates the light polarization when an electric field is applied (Kerr effect), allowing for super-rapid turning of lens orientation to record some amazing images.

SOURCES
io9 website story
Raptronic cameras and photos

The ongoing nuclear disaster in Japan has been upgraded to a 7, the highest possible threat level. Authorities say that, despite the potential radiation exposure to people in the surrounding area, the Japanese disaster is still only emitting about 10% of the radiation at Chernobyl. More soon...

I love XKCD. How is it that a comic strip has such good technical explanations? Anyway, here you'll find a chart of the ionizing radiation dose a person can absorb from various sources. Check it out. You'll feel much smarter.

The remaining 50 emergency workers were pulled from the Fukushima Daiichi plant tonight for an hour or so due to a spike in radiation levels. (They're back in, now. For more on just how much radioactivity nuclear operators can be exposed to, read this NYTimes article.) The disaster is now rated a 6 on the 7-point scale. Three Mile Island was a 5; Chernobyl was a 7. 200,000 people within a 12 mile radius of the power plant have been evacuated. Another 140,000 people within a 20 mile radius of the area have been told to stay inside, and a 19 mile no-fly zone has been imposed over the plant. The only good news tonight seems to be that the winds are blowing out to sea, helping to disperse the radiation away from populated areas.

This MSNBC update also includes a good infographic about how much radiation people are generally exposed to.

The Washington Post has a good interactive feature that sums up the crisis.

The NYTimes Green Blog is taking reader questions about the nuclear disaster, and will be posting answers tomorrow.

More in the morning...

Submarines collide
Submarines collideCourtesy mateus27_24-25

Antisonar device works

Two nuclear submarines using anti-sonar technology apparently could not see each other when they collided somewhere in the Atlantic ocean.

"This is clearly a one-in-a-million chance when you think about how big the Atlantic is. It is actually unbelievable that something happened."

Click this link to read more in the Daily Tech: Collision leaves two nuclear-armed subs badly damaged,

Nov
13
2008

It's a new day in America: Where should our energy come from now?
It's a new day in America: Where should our energy come from now?Courtesy timsamoff
On January 21, 2009, there’s going to be a brand new administration in the White house. Defining the energy policy of the United States is going to be a big issue, and one that’s likely to get tackled early on.

The members of the Obama Administration are going to have their own ideas about how our country should get its energy, but what do you think?

Is green energy your one and only? Are you a coal man? A nuclear gal? Or do you fall asleep murmuring “drill, baby, drill”?

Some options are going to be more expensive than others, each will affect the environment differently, and some are going to take more time before they’re ready. So what’s it going to be?

Voice your opinion in Science Buzz’s new poll: Energy and the Obama Administration.

You might not have been able to vote on November 4, but you can vote now, and you can let everyone know why you think what you think.

Which forms of energy production should the government be subsidizing more? Nuclear or renewable technologies like wind and solar?

Apr
20
2008

Defense against deadly doses of radiation

Radiation defense
Radiation defenseCourtesy Fibonacci
Whether by nuclear accident, radiation treatment, or a dirty bomb, exposure to formerly deadly doses of radiation now might be survivable. Cleveland Biolabs, Inc. (CBLI) has a compound called Protectan that has rescued mammals from lethal doses of radiation. The effectiveness of Protectans whether injected before or after radiation exposure indicates that these compounds have great potential as practical, as well as effective and non-toxic, biodefense measures.

Why is radiation deadly?

The lethality of high dose ionizing radiation is largely due to development of Acute Radiation Syndrome (ARS) caused by massive apoptosis in radiosensitive organs, including:

  • intestinal cells (leading to nausea)
  • hair follicles (leading to hair loss)
  • spermatocytes (leading to male infertility)
  • hematopoietic (HP) cells (leading to immunosuppression)

How antiradiation pharmaceuticals work

Cleveland Biolabs, Inc. is currently developing derivatives of microbial factors that are natural regulators of apoptosis. Click here for a more complete discussion of how Protactan's work as radiation antidotes.

  • Protectan CBLB502 is a rationally designed recombinant derivative of the bacterial protein, flagellin, which binds and activates the mammalian TLR5 cell surface receptor. Moreover, TLR5 is expressed on the endothelial cells of the small intestine lamina propria, the most radiosensitive part of the GI tract
  • CBLB600 Series Protectans are synthetic derivatives of mycoplasma lipopeptide, which promote activation of the anti-apoptotic NF-kappaB pathway associated with acute radiation syndrome

Here is a link to the research paper in Science titled
An Agonist of Toll-Like Receptor 5 Has Radioprotective Activity in Mouse and Primate Models
More research papers can be accessed at CBLI Publications

Mar
01
2008

Renewed hope for nuclear fusion

Magnetized Target Fusion
Magnetized Target FusionCourtesy Los Alamos fusion energy sciences
Nuclear fusion has been "just around the corner" for more than 50 years. Fusion reactions occur in the sun and in hydrogen bombs. Tremendous quantities of energy can result from the fusion of hydrogen atoms into helium.

VCs bet big money on fusion power futures

Wealthy investors in California are betting hundreds of millions of dollars that the difficulties of producing power with fusion may soon be solved. The CEO of Chrysalix Energy Venture Capital thinks that "Within five years, large companies will start to think about building fusion reactors." Chrysalix invested in General Fusion, a Canadian company that says it has found a way to hurdle many of the technical problems surrounding fusion.

The company's ultimate plan is to build small fusion reactors that can produce around 100 megawatts of power. The plants would cost around $50 million. That could allow the company to generate electricity at about 4 cents per kilowatt hour, making it competitive with conventional electricity.c/net News.com

Magnetized Target Fusion

Using a technique called Magnetized Target Fusion (MTF), a current within a plasma containing lithium creates a magnetic field which allows it to be squeezed . The resulting temperature spike breaks down

the lithium into helium and tritium. Tritium, an unstable form of hydrogen, is separated and then mixed with deuterium, another form of hydrogen. The two fuse and make helium, a reaction that releases energy that can be harvested.

For updates check this General Fusion Inc. wiki.