Fukushima, Nikkei, and Nuclear Engineers

[clifp]

My social media has exploded with concerns about the latest revelations about the leaking coming from Fukoshima.

Most of my international investments are in Vanguard total international stock market. However, I do have a modest position in VPL which is roughly 1/2 invested in Japan equities. It has been a dog and some ways I am looking for an excuse to sell, on the other hand I really want to be overweight in Asia when it comes to international equities. The Nikkei seems to be taking everything in stride.

This board has lots of nuclear engineers, and understand at least one commercial operator/instructor. I've spent a fair amount of googling, and I can do math pretty well but I am confused about radiation units. So I have questions for any of you fine folks who spent a chunk of your life dealing with this stuff.

1. How much radiation is in all of these cooling holding containers.
2. What would the impact of all of these containers getting dumped in the ocean, on Japan, Hawaii and the US
3. How much radiation is in the reactors (i.e how many KG of uranium and how radioactive is it)? Have they removed the fuel rods?
4. If all of that material was leaked into the ocean (i.e the containment vessel was breached) what would the impact be on Japan, Hawaii, and US.

 

[martyp]

This might answer your question:

snopes.com: Fukushima Emergency

 

[StickInTheMud]

Unfortunately, I don't know the specific answers to your questions, but I believe there is still substantial risk of further disaster at the plant.

They have not yet removed the fuel rods from the damaged reactors, and are still in the process of continuously pumping water through them to keep them cool. Right now, it's pretty much all in a holding pattern until they finally begin to remove the fuel. That's when the eyes of the world will turn back to Fukushima.

Someone explained the process of removing the fuel like playing the "crane game" in an arcade, but instead of cuddly stuffed animals, it's nuclear fuel rods. The one advantage in this version of the game is that the claw isn't rigged to let go everything it picks up. The disadvantage is that there is a significant amount of debris that must be navigated through, and if the rods break or drop, then the reactor can/probably will meltdown.

Personally, you couldn't pay me enough to step foot in Japan until that mess is all cleaned up and the fuel has been successfully extracted from the reactors.

 

[Gumby]

Someone explained the process of removing the fuel like playing the "crane game" in an arcade, but instead of cuddly stuffed animals, it's nuclear fuel rods. The one advantage in this version of the game is that the claw isn't rigged to let go everything it picks up. The disadvantage is that there is a significant amount of debris that must be navigated through, and if the rods break or drop, then the reactor can/probably will meltdown.

The process of removing spent fuel from a nuclear reactor is well known; it is done approximately every 18 months at each of the approximately 100 nuclear plants in the US. So positing it as something uniquely dangerous is a bit of an overstatement. Removing spent fuel from a reactor that has experienced a meltdown (as three of the Fukushima units already did during the initial accident) is substantially more complex, since the fuel is not in its normal geometry and there are debris, as you have noted. But we already have experience in doing just that with the Three Mile Island plant in Pennsylvania.

They will also need to remove the fuel from the Unit 4 spent fuel storage pool (probably to dry cask storage). Again, this is an evolution that has been done many times before, although I will grant that if the fuel in the pool is damaged, it will be more difficult.

Yes, I have defueled a nuclear reactor. Twice.

 

[StickInTheMud]

The process of removing spent fuel from a nuclear reactor is well known; it is done approximately every 18 months at each of the approximately 100 nuclear plants in the US. So positing it as something uniquely dangerous is a bit of an overstatement...

Yes, I have defueled a nuclear reactor. Twice.

Fair enough. I'll defer to your expertise.

What do you think about TEPCO's ability to manage the situation? I see they now have approval to move forward with the removal, whenever that will be.

 

[frayne]

Not a degreed engineer but I was an operations superintendent at a refinery/chemical complex for a number of years. Of all I have read or seen reported, Tepco still has a tiger by the tail and a boat load of liability to put it conservatively. Fukushima was truly a catastrophic event and from most indications is still ongoing.

 

[Gumby]

What do you think about TEPCO's ability to manage the situation?

I honestly couldn't say. I have been out of the nuclear business since 1989.

 

[kramer]

I found this New York Times article interesting about the excess fear surrounding nuclear radiation and how the facts just don't bear out the feared danger:

http://www.nytimes.com/2013/10/22/opinion/fear-vs-radiation-the-mismatch.html?_r=0

Beginning shortly after World War II, epidemiologists and radiation biologists began tracking atomic bomb survivors. Researchers have followed roughly 112,600 Japanese: 86,611 who had been within 10 kilometers of the center of the explosions, and 26,000 who were not exposed.

The most current analysis estimates that, out of 10,929 people in the exposed population who have died of cancer, only 527 of those deaths were caused by radiation from the atomic bombs. For the entire population exposed, in many cases to extremely high levels of radiation, that’s an excess cancer mortality rate of about two-thirds of 1 percent.

These studies have also found that, more than two generations later, there have been no multigenerational genetic effects on humans, Godzilla and the mutant giant ants in the 1954 film “Them!” notwithstanding. Fetal exposure in utero produced horrible birth defects, but no permanent genetic damage.

Perhaps most importantly, research on the bomb survivors has found that at lower doses, below 100 millisieverts, radiation causes no detectable elevations in normal rates of illness and disease. (Among several measures of radiation exposure, sieverts reflect the biological effects of radiation.) The vast majority of the doses received by people living near Fukushima or Chernobyl were well below this 100 millisievert threshold.

The robust evidence that ionizing radiation is a relatively low health risk dramatically contradicts common fears.

 

[mpeirce]

> excess fear surrounding nuclear radiation

Back when I was in college I worked with some folks who were developing what we now call MRI (Magnetic Resonance Imaging). Back in those days (early 80's) the term was NMR (Nuclear Magnetic Resonance) imaging.

Someone got smart and changed the name from NMR to MRI. Very smart.

BTW, the N was in the name because of the magnetic interactions with the Nucleus, not because of nuclear fission/fusion reactions. No ionizing radiation (like X-Rays) is involved at all.

The terms nuclear and atomic has been thoroughly demonized.