Radiation?

[herm0016]

measurable health effects for acute radiation exposure are typically seen for doses of over 100 mrem (to all of the body or to one specific part)

this is the part i was talking about. acute does not happen till 100's of rem. not mrem. 100 mRem is less dose than I received in my most active year.

 

[DeathRayLoveMachine]

i am an NRC certified radiatoin supervisor and handle chemical and electronic sources, gamma and neutron up to an equivalent of 50 ci.

I haven't worked with this stuff in years so I'll gladly defer to your expertise.

i don't know where you get your info, but it's wrong.

I was just working off of memory. I tried googling for some figures first, but then I got lazy.

100 mSv is an increase cancer risk. which is 10 Rem. your figures are way off. acute exposure is not seen until 2000 mSv or 200 rem.

http://lowdose.energy.gov/images/ig_pics/026_dose-ranges-sievert.jpg

My estimate for increased cancer risk is based on radon exposure (which I think has measurable health effects over a population at exposure levels as low as several hundred mrem/year), and my estimate for measurable effects due to acute radiation exposure is based on damage to the corneas (which I'm sure you know are highly sensitive to radiation). I'm not saying these levels are catastrophic or even particularly dangerous; they're just the lowest measurable levels I was able to recall offhand.

I'm sure you know more about this than me, but I'm also sure you'd agree that it's best not to take in an extra 500 mrem/year in the form of radon gas in your lungs, or 100 mrem as a solid dose straight into your eyeballs.

 

[Revolution 11]

Buckley AFB would be an extremely high priority target. Cheyenne Mountain, about 80 miles away, would also be targeted by multiple warheads.

That's what I meant. Military assets will contribute a lot more background radiation than Denver. I am sure it is a nice city but it is not very important in a war.

 

[QuantumPion]

Just to give you some rough estimates:
300 mrem/year is considered the upper limit for levels of "safe" natural background radiation

This is incorrect. 300 mrem/year is the average background radiation received per year for typical people. If you live in high altitude places like Colorado or places with high natural background sources your yearly background dose can be much higher. Denver I believe was about double the typical, being around 500-600 mrem/year IIRC. Some places in Iran and India which have natural thorium deposits can have background dose rates upwards of 10,000 mrem/year.

background radiation higher than about 1000 mrem/year is linked to increased cancer rates

Also incorrect. There is no scientific evidence linking low doses of radiation to increase cancer risks. This is surprising to most people as most assume any radiation increases cancer risk. The fact is that while any radiation absorbed could potentially cause DNA-alterning damage which eventually leads to cancer, statistically the chances are so low and there are so many other causes of cancer that there is no way to know for sure.

Note that the US Federal radiation dose limit for workers in nuclear/radiation related fields is 5000 mrem/year. This is the value that is considered the minimum value assumed to not have perceptibly increased cancer risk.

 

[Blue_Max]

Really?

Do you know how large the Pacific Ocean is? Can you cite any specific measurable issues? Seriously?

You're more likely to die from di-hydrogen monoxide poisoning...

troooolllololol

They should really ban the stuff...

Oh, by the way;
http://www.dailytech.com/Another+Fukushima+Storage+Tank+is+Leaking/article33489.htm
Back in August, it was reported that Fukushima is leaking about 300 tonnes of toxic water into the Pacific Ocean per day. The water, which is seeping through the soil and through the plant into the ocean, contains radioactive particles of cesium, tritium and strontium.
[...]The water that leaked had 200,000 becquerels per liter of radioactive isotopes, including strontium 90. The legal limit for strontium 90 is 30 becquerels per liter.
You radioactivity experts able to extrapolate anything from the jargle?

 

[Yuriman]

Oh, by the way;
http://www.dailytech.com/Another+Fukushima+Storage+Tank+is+Leaking/article33489.htm
Back in August, it was reported that Fukushima is leaking about 300 tonnes of toxic water into the Pacific Ocean per day. The water, which is seeping through the soil and through the plant into the ocean, contains radioactive particles of cesium, tritium and strontium.
[...]The water that leaked had 200,000 becquerels per liter of radioactive isotopes, including strontium 90. The legal limit for strontium 90 is 30 becquerels per liter.
You radioactivity experts able to extrapolate anything from the jargle?

What it boils down to is, the background levels of radiation in the pacific would go up by less than 1% if they were to just take a bulldozer and push the whole damn plant into the water. Think about the atomic testing that was done in the south pacific - FAR more radiation was released that way, and the half life of U is in hundreds of millions of years so the levels today are not significantly different.

There may be some local health risks until the radiation has dispersed, but what is contained in that plant isn't even a drop in the ocean... literally.

EDIT: Not that I'm advocating we push it in the ocean - I think the atomic testing was an idiot idea too, but this is far less worrisome.

 

[Brian Stirling]

What it boils down to is, the background levels of radiation in the pacific would go up by less than 1% if they were to just take a bulldozer and push the whole damn plant into the water. Think about the atomic testing that was done in the south pacific - FAR more radiation was released that way, and the half life of U is in hundreds of millions of years so the levels today are not significantly different.

There may be some local health risks until the radiation has dispersed, but what is contained in that plant isn't even a drop in the ocean... literally.

EDIT: Not that I'm advocating we push it in the ocean - I think the atomic testing was an idiot idea too, but this is far less worrisome.

Not so sure about that ...

How many pounds of Uranium and Plutonium were used in all the testing in the Pacific?

How many pounds of Uranium and Plutonium were present in the reactors at Fukushima? Now, what percentage of the radioactive material at those reactors has worked it's way into the ocean?

As I recall ... the total loading of Uranium in a single power plant reactor is on the order of a couple hundred thousand pounds versus, maybe a few hundred for bomb and casing. There were four reactors that shit the bed so that could total something close to a million pounds of Uranium and some traces of Plutonium so that it just 1% escaped we'd be looking at about 10,000 pounds of nasties...


Brian

 

[John Connor]

I asked a question about radiation, not to open a god damn debate about Japan's reactors.

 

[Soundmanred]

I asked a question about radiation, not to open a god damn debate about Japan's reactors.

Your question was answered, they're just keeping things interesting.
Or do you want to talk about "Skynet" more to stay on topic?

 

[Blue_Max]

I asked a question about radiation, not to open a god damn debate about Japan's reactors.

You're right... that's not related to radiation or have any present relevance AT ALL.
:whiste:

 

[John Connor]

Tell me how my question on what radiation levels humans are susceptible to has anything to do with a nuclear reactor leak? This is the highly technical thread. I want to hear about whether 100 CPM is what I should be worried about when a nuclear blast goes off. Not some small radiation leak all the way in Japan.

I want the technical details on what is the acceptable radiation limit that a human can tolerate? Not a off topic tit for tat argument on Fukushima.

 

[John Connor]

Or do you want to talk about "Skynet" more to stay on topic?

That's not the topic. :thumbsdown:

 

[pm]

Maybe it's a living in Colorado thing, but I built a Geiger counter over the summer - and I bought a sample to test it (I'm using a thorium coated Coleman lantern mantle - cost ~$4 on Ebay including shipping and definitely works well).

For tubes, I'm using an LND 712 - which is alpha/beta/gamma.

John, when you get yours maybe we could meet up for a cup of coffee or something down in Loveland and test out our respective Geiger counters.

 

[Blue_Max]

1) It's no "small leak" - it's huge, continuous, and being downplayed like you wouldn't believe. If you're concerned about radiation, this is a real source, right now. Chernobyl is still a strong concern as well, as the flimsy sarcophagus is beginning to fail and construction of the new sheath has been stalled for years.

2) Your request is a reasonable one, since the greatest threat is from a terrorist attack of limited & small nuclear weapons smuggled on the ground. The details from Hiroshima are actually quite relevant in this case. Theatre-wide nuclear warfare is almost pointless to calculate survival of with today's payloads.

(Hell - let's give the world a reboot with MIRVs peppering the entire land surface area with 10kt warheads to keep the radiation high at ground level rather than the upper atmosphere like Tsar Bomba in my avatar.)

Even if the human body survives a moderate dose of radiation, your genetics may be deeply damaged, resulting in dead/deformed babies, as seen in both Hiroshima AND Chernobyl. Better hope there's enough "clean" humanity elsewhere to fill the void because while many may survive the first wave, there may not be much regeneration afterwards.

 

[herm0016]

Maybe it's a living in Colorado thing, but I built a Geiger counter over the summer - and I bought a sample to test it (I'm using a thorium coated Coleman lantern mantle - cost ~$4 on Ebay including shipping and definitely works well).

For tubes, I'm using an LND 712 - which is alpha/beta/gamma.

John, when you get yours maybe we could meet up for a cup of coffee or something down in Loveland and test out our respective Geiger counters.

i have a set of old civil defence detectors i could add to a coffee meeting.

 

[John Connor]

1) It's no "small leak" - it's huge, continuous, and being downplayed like you wouldn't believe. If you're concerned about radiation, this is a real source, right now. Chernobyl is still a strong concern as well, as the flimsy sarcophagus is beginning to fail and construction of the new sheath has been stalled for years.

2) Your request is a reasonable one, since the greatest threat is from a terrorist attack of limited & small nuclear weapons smuggled on the ground. The details from Hiroshima are actually quite relevant in this case. Theatre-wide nuclear warfare is almost pointless to calculate survival of with today's payloads.

(Hell - let's give the world a reboot with MIRVs peppering the entire land surface area with 10kt warheads to keep the radiation high at ground level rather than the upper atmosphere like Tsar Bomba in my avatar.)

Even if the human body survives a moderate dose of radiation, your genetics may be deeply damaged, resulting in dead/deformed babies, as seen in both Hiroshima AND Chernobyl. Better hope there's enough "clean" humanity elsewhere to fill the void because while many may survive the first wave, there may not be much regeneration afterwards.

http://www.youtube.com/watch?v=cVZxh1WDOec

 

[John Connor]

Maybe it's a living in Colorado thing, but I built a Geiger counter over the summer - and I bought a sample to test it (I'm using a thorium coated Coleman lantern mantle - cost ~$4 on Ebay including shipping and definitely works well).

For tubes, I'm using an LND 712 - which is alpha/beta/gamma.

John, when you get yours maybe we could meet up for a cup of coffee or something down in Loveland and test out our respective Geiger counters.

http://www.amazon.com/Images-SI-Inc-...ef=pd_sim_hi_5

I would, but I don't drive. I like Starbucks. How old are you? LOL I just turned 33.

 

[Blue_Max]

...screw you, then. Get your own damn info.

 

[John Connor]

LMAO! I wasn't asking about Fukushima in the first place! And you provided ZERO info. on what I wanted to know.

 

[exdeath]

Not so sure about that ...

How many pounds of Uranium and Plutonium were used in all the testing in the Pacific?

How many pounds of Uranium and Plutonium were present in the reactors at Fukushima? Now, what percentage of the radioactive material at those reactors has worked it's way into the ocean?

As I recall ... the total loading of Uranium in a single power plant reactor is on the order of a couple hundred thousand pounds versus, maybe a few hundred for bomb and casing. There were four reactors that shit the bed so that could total something close to a million pounds of Uranium and some traces of Plutonium so that it just 1% escaped we'd be looking at about 10,000 pounds of nasties...


Brian

1000s of tons of fast neutron irradiated tamper and casing material in bombs that gets vaporized and dispersed.

Castle Bravo alone probably dwarfs Fukushima in contamination.

Remember also we are talking 5% vs 90%+ concentrations of the active dangerous isotopes, granted with bombs we mostly have fission products and not so much raw U235 and Pu239.

But then you could argue fission products are more dangerous when they are numerous elements used in biology and easily welcomed into and incorporated into your tissue like iodine etc. Just plain Uranium while a radiological hazard is less of a biological hazard.

Lots of variables to consider.

 

[Biftheunderstudy]

Great, thanks exdeath, now I spent the last 2.5 hours procrastinating on wikipedia about castle bravo and various other related links.

Other pertinent information is that castle bravo has a WAY higher death/cancer/birth defect rate than fukushima has or ever will.

 

[Blue_Max]

LMAO! I wasn't asking about Fukushima in the first place! And you provided ZERO info. on what I wanted to know.

Fine. I'll polish up a nice, silver platter on which to serve the VERY specific information you so politely requested...

[to all]
I'm very interested in the subject of radioactive toxicity as well and have been for almost 30 years. I'll never understand why some people are so afraid of a potential nuclear strike but don't give a crap about the genuine issue right in front of them...

I'll start searching, again, for more info DIRECTLY related to nuclear strike data and the radiation absorption from it (assuming you're unharmed from light, shockwave, flying glass, pressure differentials, and lingering firestorm.)

IN THE MEANTIME, I found a nice article response on the subject of Chernobyl vs Hiroshima:
While they work on the same principles, the detonation of an atomic bomb and the meltdown of a nuclear plant are two very different processes.

An atomic bomb is based on the idea of releasing as much energy from a runaway nuclear fission reaction as possible in the shortest amount of time. The idea being to create as much devastating damage as possible immediately so as to nullify enemy forces or intimidate the opposing side into surrender. Both effectively ensuring the conflict ends quickly. Thus, it would be important that the area bombed does not remain uninhabitable long after the two sides make peace (Ok, that's my own speculation, but I think it's a nice ideal to work with).

A nuclear reactor is based on the idea of producing low amounts of power using a controlled and sustained nuclear fission reaction. The point being that it does not release all of the energy at once and slower reaction processes are used to ensure maximum lifetime of the nuclear fuel.

Moving beyond the ideas behind each, the radioactive isotopes created in an atomic blast are relatively short-lived due to the nature of the blast and the fact that they are normally detonated above the ground to increase destructive power of the concussive wave. Most radioactive materials from an atomic blast have a maximum half-life of 50 years.

However, in the Chernobyl meltdown, most of the actual exploding was due to containment failure and explosions from steam build-up. Chunks of fuel rods and irradiated graphite rods remained intact. Furthermore, the reaction has, bot initially and over its life, produced a far higher amount of radioactive materials. This is partly due to the nature of the reaction, the existence of intact fuel to this date, and that the explosion happened at ground level. A fission explosion at ground level creates more radioactive isotopes due to neutron activation in soil. Furthermore, the half-lives of the isotopes made in the Chernobyl accident (because of the nature of the process) are considerably longer. It is estimated that the area will not be habitable for humans for another 20 000 years (Edit: to prevent further debate I rechecked this number. That is the time before the area within the cement sarcophagus - the exact location of the blast - becomes safe. The surrounding area varies between 20 years and several hundred due to uneven contamination).

Long story short, an atomic bomb is, like other bombs, designed to achieve the most destructive force possible over a short amount of time. The reaction process that accomplishes this ends up creating short-lived radioactive particles, which means the initial radiation burst is extremely high but falls off rapidly. Whereas a nuclear reactor is designed to utilize the full extent of fission in producing power from a slow, sustained reaction process. This reaction results in the creation of nuclear waste materials that are relatively long-lived, which means that the initial radiation burst from a meltdown may be much lower than that of a bomb, but it lasts much longer.

In the global perspective: an atomic bomb may be hazardous to the health of those nearby, but a meltdown spreads radiation across the planet for years. At this point, everyone on Earth has averaged an extra 21 days of background radiation exposure per person due to Chernobyl. This is one of the reasons Chernobyl was a level 7 nuclear event.

All of this contribute to why even though Hiroshima had an atomic bomb detonate, it is Chernobyl (and Fukushima too I'll wager) that remains uninhabitable.

As pointed out, one thing I forgot to mention is that the amount of fissionable material in an atomic bomb is usually considerably less than the amount housed in a nuclear reactor. A standard nuclear reactor can consume 50,000lb of fuel in a year, whereas little boy held significantly less (around 100−150lb). Obviously, having more fissionable material drastically increases the amount of radiation that can be output as well as the amount of radioactive isotopes. For example, the meltdown at Chernobyl released 25 times more Iodine isotope than the Hiroshima bomb (an isotope that is relatively long-lived and dangerous to humans) and 890 times more Cesium-137 (not as long lived, but still a danger while it is present).

 

[Blue_Max]

http://inmotion.magnumphotos.com/essay/chernobyl
Some great historical pictures from Chernobyl - warning, many disturbing images of what happened to the children from that radiation. Maybe you guys will take nuclear plants a little more seriously...


[switching to bomb mode now]

 

[Hugo Drax]

The Geiger counter will click on alpha beta and gamma radiation. But the penetrating radiation, the gamma is what you measure when talking about exposure.

Geiger counters are not as sensitive to gamma as it is to beta.

So when you put that uranium ore close to the Geiger counter count the amount of clicks per minute, that is the total count of ionizing events that occurred in the tube then Put a few sheets of aluminium paper between the Geiger counter and the uranium. Count the number of clicks per minute and now you have your gamma reading.

That is what your exposure reading would be. You use cpm for alpha and beta

And microsievert or microrotegens for gamma.

The spec sheet for the tube should tell you how many cpm per microsievert on exposure to gamma it will generate.

That way you can divide that number from the spec sheet information into your cpm count generated by the alpha/beta shielded gm tube to get your exposure reading in microsieverts per hour.

 

[Hugo Drax]

On another note not all gamma radiation is the same, just like the color spectrum of light. There is an energy spectrum of gamma radiation. Different radioactive isotopes generate unique gamma radiation energy, some more penetrating and stronger than others.

Then you have neutron radiation, super dangerous. Neutron radiation can actually turn other things that were not radioactive into radioactive materials.

Anyhow it's interesting stuff.