The reactors at Fukushima continue to be hotter than "cold shutdown" levels, and at least one reactor (#1) is probably leaking from the core containment vessel. Fission products in high amounts, high pressure, and high temperature indicate that something close to fission is still happening although an apparent lack of large quantities of short lived isotopes may indicate that it has been a while since extensive fission has occurred in the leaking reactor.
There is still concern over possible hydrogen explosions and unexplained "white smoke" continues to rise from several buildings on site.
There is now concern that the spent storage pool for reactor #4 is leaking, and there is concern that it will not be possible to apply as much water as needed to some of the storage pools for fear that they will collapse. In addition, there is concern that applying too much water to at least one of the rectors is causing structural decay of the building that will make it collapse if there is an earthquake.
There is real progress in hooking up the plants to outside power sources, and in fact, it will eventually be connected to redundant outside power sources. The degree to which this is completed is unclear.
Tens of thousands of domestic animals (chickens being the most abundant, but also cattle and swine) have died from neglect in the evacuation zone, and government officials are now starting the process of euthanasia on some of the rest of them. Local civic leaders have reached a state of depression and despair and collectively state that recovery of the affected communities is impossible.
One of the most interesting recent outcomes of this event (aside from the fascinating engineering and nuclear physics) is the call to prosecute judges that adjudicated the regulatory process early on in licensing of this and other nuclear power plants in Japan. The claim is being made that Judges sided with the Nuclear Power Industry on issues of safety. The reason this is so interesting is that Nuclear Power Apologists have used a number of techniques to support certain decisions related to Nuclear Power Plant design, construction, operation, and licensing which would likely be exposed and debunked as part of such an investigation and trial. This is a potentially very positive thing for those of us who consider ourselves rationalists and skeptics. A critical examination of how we integrate scientific knowledge and engineering with the development of energy policy in the broader context of political policy would be very productive.
And in doing so, it would be very important to re-examine Chernobyl. The current widespread belief regarding Chernobyl falls into two categories: 1) It was a horrid disaster in which thousands died and/or got cancer and 2) Nothing really bad happened outside the site of the fire itself. The former is the view of the anti-nuclear pole, the latter of the Nuclear Power Apologists. Neither is true. It will be necessary to get Chernobyl figured out and on the table as part of the process of examining Fukushima.
And now, Ana's Feed:
Co-op sells banned spinach to consumers in eastern Japan - April 21, Kyodo
-A Tokyo-based cooperative has delivered spinach grown in the town of Tako, Chiba Prefecture, to consumers in three eastern Japan prefectures despite a government ban on shipments due to concerns about radiation, the Chiba prefectural government said Thursday.
Radiation over 100 microsieverts detected 2-3 km from troubled plant - Kyodo
- Radiation levels of over 100 microsieverts per hour were measured at four locations 2 to 3 kilometers from the crippled Fukushima Daiichi nuclear plant from late last month, the science ministry said Thursday as it released such data for the first time.
- All four readings of over 100 microsieverts were taken in the town of Okuma in Fukushima Prefecture, and about 2 to 3 km from the nuclear plant, with the highest reading of 124 microsieverts measured at a location around 2 km west-northwest of the complex.
The Chernobyl deniers use far too simple a measure of radiation risk - The Guardian: Those who downplay the dangers of nuclear energy are wrong to focus only on dose.
- "In his article on "the confusing world of radiation exposure", readers' editor Chris Elliott was right to point out that getting a whole year's sunshine in an hour would fry him to a crisp (Open door, 4 April). Radiation dose rate is important. What he didn't say is that "dose density" is important too.
- The "sievert", as Elliott says, is a dose unit for quantifying radiation risk. He did not add that it assumes dose density is uniform. "There are many kinds of radiation", he says, but he does not mention how they differ. In fact, external sources like cosmic rays and x-rays distribute their energy evenly, like the sun; others, notably alpha-emitters like uranium, are extremely uneven in the way they irradiate body tissue once they have been inhaled or swallowed."
Evacuation zone widened beyond 20km from Fukushima nuclear plant - April 22, Kyodo
- The government on Friday added some towns outside a 20-kilometer radius of the crisis-hit Fukushima Daiichi nuclear power plant to the list of areas covered by its evacuation directive, due to concerns over high cumulative levels of radiation.
Chernobyl: distorted reality and unanswered questions - April 21, 2011, Greenpeace Blog
- "We have just returned after completing an important mission in Ukraine - taking around 70 journalists from 18 countries with us to Chernobyl, nearly 25 years after the nuclear catastrophe. It was one of the largest media trips Greenpeace has organized. These seasoned journalists asked critical and insightful questions, none of them easily moved.
- But many of them were deeply disturbed by what they saw and heard - often by the mundane details that were mentioned matter-of-factly by the interviewees."
Scenes from the Fukushima Exclusion Zone - Good Blog
- "In the wake of the earthquake and tsunami in Japan, photographer Donald Weber set out for the "exclusion zone" around the Fukushima nuclear reactors. Residents of this buffer area were forced to evacuate immediately after the tsunami struck, leaving an eerie abandoned urban landscape. Besides the military, Weber and his partner were, he believes, "the only other people to go to the exclusion zone and actually see what the reality is there.""
TEPCO president apologizes to residents - NHK, April 22, 2100
Reactor 1 water level concerns - NHK, April 23, 2011
- The Japanese government has expressed concern about the structural strength of the Fukushima Dai-ichi nuclear power plant's Number 1 reactor. It says the ongoing water injections may be making the vessel less earthquake resistant.
- At the Number 1 reactor, where fuel rods are believed to be the most seriously damaged, six tons of water are being injected every hour.
- TEPCO believes the water is vaporizing, then condensing in the containment vessel.
Cattle in the restricted zone - NHK, April 23, 2011
- Tens of thousands of farm animals have been abandoned in the evacuation zone surrounding the Fukushima Dai-ichi nuclear power plant. Many of them reportedly have already died.
- Fukushima Prefecture authorities say there were about three-hundred livestock farms with three-thousand cows, 30-thousand pigs, and 600-thousand chickens.
- Some farmers are requesting that they be allowed to euthanize the remaining animals.
- The agriculture ministry says, however, it will be difficult to allow people to enter the restricted area to euthanize or feed the animals.
Tokyo Takes Over PR From Plant Operator - Wall Street Journal
- "Tepco's briefings have at times turned confrontational. "You guys lack accountability," some reporters have shouted, eliciting apologies from Tepco spokesmen. "Who is the person overseeing this operation?" asked one reporter at a briefing earlier this month on Tepco's planned discharge of lightly radioactive water into the ocean. "Why can he not come here? Tell me his name. Who is it? Go up and find out right now. Go right now. Go right now.""
Periodic health checkups mulled for Fukushima residents - April 23, Kyodo
- The Fukushima prefectural government is considering implementing regular health checkups of its residents, while examining the health of children in the long term, in the wake of the nuclear emergency there, its officials said Saturday.
TEPCO to cautiously inject water in No.4 fuel pool - NHK, April 23, 2011
- Tokyo Electric Power Company has decided to be more cautious about the volume of cooling water injected into the spent fuel pool of one of its reactors.
- This is due to fear that the reactor building might be further damaged by the weight of the water itself.
TEPCO must not be allowed to resume reactor operations: Fukushima gov. - April 22, Kyodo
- Fukushima Gov. Yuhei Sato said Friday he will never allow Tokyo Electric Power Co. to resume operations at its Fukushima Daiichi nuclear power plant, crippled by the March 11 earthquake and tsunami.
Workers locked in battle at Fukushima, exposure to radiation rising - April 23, Kyodo
- Workers at a nuclear power plant damaged by last month's earthquake and tsunami that devastated Japan's northeast continued battling to deal with radioactive water Saturday as their exposure to radiation is constantly increasing.
Kitazawa thanks special US nuclear rescue team - NHK, April 23, 2011
- Defense Minister Toshimi Kitazawa has expressed gratitude to a special US military unit that has been dispatched to Japan to stand ready for an emergency at the disaster-hit Fukushima Daiichi nuclear power plant.
- Kitazawa visited the US Yokota Air Base in Tokyo on Saturday, where about 150 members of the special US force are standing by to respond to nuclear emergencies.
Mayors see little prospect of rebuilding lives - NHK, April 24
- An NHK survey of municipalities affected by the March 11th disasters has found that 60 percent of them see little or no prospect of rebuilding residents' lives.
- The mayors of 42 cities, towns and villages in Iwate, Miyagi and Fukushima Prefectures responded to the survey conducted between April 19th and 22nd.
- 8 mayors, including those of Iwate's Yamada Town, Miyagi's Watari Town and Fukushima's Futaba Town said there is no prospect of reconstructing residents' livelihoods.
FEATURE: Judges tend to side with utilities in atomic power plant cases - April 25, Kyodo
- The risk of an earthquake causing critical damage to a nuclear power plant has been the subject of lawsuits filed by local residents in various parts of Japan over the years, but to date none of these legal actions has led to operations at a plant being suspended.
- The courts have been inclined to accept arguments that nuclear power plants are safe, citing the highly technical nature of atomic power generation. In light of the ongoing crisis at Fukushima, however, critics say the judges should be held accountable for abandoning their role to properly scrutinize such cases.
Anti-nuclear plant candidates secure some seats in local elections - April 25, Kyodo
- A number of opponents of nuclear power plants won seats in the assemblies of host municipalities in Sunday's nationwide local elections in the wake of the crisis at the Fukushima Daiichi complex, including one candidate who drew the largest number of votes in his town.
Fukushima Pref. to cull dying livestock in 20-km radius of nuke plant - April 25, Kyodo
- Six Fukushima prefectural government workers dressed in protective outfits went into the no-entry zone within a 20-kilometer radius of the crisis-hit nuclear power plant in the northeastern Japanese prefecture Monday to begin work to cull starving livestock.
Monitoring rising temperatures - NHK, April 25, 2011
- The operator of the troubled Fukushima Daiichi nuclear power plant is carefully monitoring the situation at the Number 4 spent fuel pool, where the water temperature is rising despite increased injections of cooling water.
- Tokyo Electric Power Company, or TEPCO, says it will inject 210 tons of water into the pool on Monday, after finding on Sunday evening that the temperature in the pool had risen to 81 degrees Celsius
Fukushima restricts park use - NHK, April 25, 2011
- Fukushima Prefecture is restricting the use of 5 of its public parks due to high levels of radiation, causing concerns among nearby residents and park visitors.
- The prefecture announced on Monday that it would limit the use of the parks to one hour a day, as radiation readings at the 5 facilities were at or above the safety limit set for outdoor activities in schools.
Rewiring starts at Fukushima Daiichi - NHK, April 25, 2011
- Tokyo Electric Power Company is rewiring the power grid at its Fukushima Daiichi nuclear plant to secure the electricity supply in case of another strong quake.
- The plant's 6 reactors are now connected in pairs to external power sources. TEPCO began connecting the cables for the No.1 and No.2 reactors with the grid for the No.5 and No.6 reactors on Monday.
- This is to ensure that if any one of the 3 outside sources is cut off, the others can be used to cool the reactors.
Radioactive materials found in Japanese bird feed - April 25, Yonhap
- Traces of radioactive materials have been detected in bird feed imported from Japan, though the concentration levels are below permissible levels, the government said Monday.
- South Korea began checking animal feed imported from Japan for radioactive containments from March 29 onwards, after the Fukushima nuclear power station started releasing radioactive materials into the environment in mid-March. As of last week, 52 shipments totaling 390.3 tons of feed have been checked.
Govt was unaware of hydrogen explosion risk - April 26, 2011, JAIF
- An advisor to Prime Minister Naoto Kan says no one in the government knew of the risk of a hydrogen explosion in the initial stages of the emergency at the Fukushima Daiichi nuclear plant.
- Hosono said he was not aware of a single nuclear expert who warned of the risk of a hydrogen blast following the venting operation. He said nitrogen inside the reactor container was supposed to prevent such explosions.
Most Japanese reactors yet to have enough backups for stable cooling - April 26, Kyodo
- Most nuclear reactors in Japan would fail to achieve a stable condition in the event that all regular power sources are lost, even though plant operators have prepared new backup power sources as well as electric generators following the crisis at the Fukushima Daiichi nuclear power plant, Kyodo News found Monday.
Japanese NGOs seek nuke-free society on 25th anniv. of Chernobyl - April 26, Kyodo
- A group of 87 nongovernmental organizations in Japan reiterated calls to achieve a nuclear-free society on Tuesday, the 25th anniversary of the Chernobyl nuclear disaster, at a time when the worst nuclear crisis since is continuing at the Fukushima Daiichi power plant.
Japan drawing on Chernobyl lesson in dealing with Fukushima: Edano - April 26, Kyodo
- Faced with the ongoing nuclear crisis in Fukushima, Japan is drawing on lessons learnt in the aftermath of the 1986 Chernobyl blast, Chief Cabinet Secretary Yukio Edano said Tuesday, on the 25th anniversary of the incident.
Radioactive water in No.3 and 4 reactors rises - April 26, JAIF
- The utility company says the water level in the tunnel of the No. 3 reactor rose to 99 centimeters below the surface as of 6 PM on Monday. That passes the level at which TEPCO plans to remove the water, but it has yet to secure storage space.
- The water level in the basement of the No.3 reactor's turbine building also rose by 10 centimeters over 3 days.
- The water level in the No. 4 reactor's turbine building rose by 20 centimeters in 10 days.
- TEPCO says water used to cool the No. 3 reactor could be leaking into No. 4 as their turbine buildings are connected.
TEPCO checks to see if water is leaking from No. 1 reactor container - April 27, Kyodo
- The operator of the crippled Fukushima Daiichi nuclear complex on Tuesday started checking to see if water is leaking from the No. 1 reactor container ahead of work to flood the vessel with water as a step to stably cool the troubled reactor.
Radiation monitors delivered to Fukushima schools - NHK, April 27, 2011
- The education board of Fukushima Prefecture, northeastern Japan, has handed out radiation monitors to local schools and kindergartens.
Radioactive water carried from No.2 reactor - NHK, April 27, 2011
- The operator of the troubled Fukushima Daiichi nuclear power plant has said it is giving top priority to transferring highly contaminated water from the No.2 reactor.
- But the firm has also found high levels of radioactive substances at the site of the No. 4 reactor.
- Last Thursday it detected 8,100 becquerels of cesium 137 and 7,800 becquerels of cesium 134 per cubic centimeter in the water in the turbine building's basement. The radioactive levels were about 250 times higher than a month before.
Big tank may be set up under Fukushima plant to store tainted water - April 27, Kyodo
- Prime Minister Naoto Kan is considering setting up a big underground tank in the compound of the radiation-spewing Fukushima Daiichi nuclear plant to prevent contaminated water from spilling into the sea, a fishery official said Wednesday.
TEPCO starts tests for more water injection - NHK, April 27, 2011
- Tokyo Electric Power Company has begun testing one of the damaged reactors at the Fukushima Daiichi nuclear power plant to see if it can move forward with its plan to submerge and cool the hot fuel rods.
- The firm says robots on Tuesday detected radiation levels of up to 1,120 millisieverts per hour inside the No.1 reactor building. It says some contaminated water may be leaking from the reactor into external pipes.
Radioactive topsoil removed from school grounds - NHK, April 27, 2011
- The city began removing the soil on Wednesday at two of the 28 public elementary and junior high schools and daycare centers.
- The removed soil is being kept under a cover at the school grounds until it can be moved to a landfill site.
Woman at nuke plant exposed to excess radiation - NHK, April 27, 2011
- A woman working at the crippled Fukushima nuclear plant was found to have been exposed to radiation of more than 3 times the legal safety limit.
- She worked at the plant for 11 days after the March 11th earthquake and tsunami, and was exposed to 17.55 millisieverts of radiation. The figure is more than 3 times the permissible amount for women, which is set at 5 millisieverts per 3 months.
- The woman may have inhaled radioactive material when taking off protective gear, as internal exposure of 13.6 millisieverts accounted for much of the total.
- The limit for workers at the Fukushima plant was raised from 100 to 250 millisieverts per year after the accident to cope with the emergency. But the limit for women was left unchanged due to their child-bearing possibilities.
Water may be leaking from No. 4 reactor fuel pool - NHK, April 27, 2011
- The operator of the troubled Fukushima Daiichi nuclear power plant says water may be leaking from the spent fuel pool of the No. 4 reactor.
- More than 1,500 spent fuel rods are stored in the pool, the largest number at the site.
Fukushima farmers protest near TEPCO headquarters - NHK, April 27, 2011
- Farmers affected by the accident at the Fukushima Daiichi nuclear power plant have demanded that its operator put it under control and compensate them as soon as possible.
- About 200 vegetable and dairy farmers from Fukushima, Chiba, Ibaraki and other prefectures took part in the protest in front of the headquarters of the Tokyo Electric Power Company, or TEPCO, in Tokyo on Tuesday.
Science ministry releases Fukushima radiation map - NHK, April 27, 2011
- Japan's science ministry has for the first time released a map projecting estimated cumulative radiation exposure near the troubled Fukushima Daiichi nuclear power plant.
- The contour map shows the amount of annual cumulative radiation that a person would be exposed to by staying outdoors for 8 hours per day through March 11th, 2012.
A 100-Year Plan for Nuclear Waste - Technology Review
- An MIT study argues that keeping it in temporary storage for decades, rather than permanently burying it, has many benefits.
Here is a link to a post saying that the japanese government is now requiring tepco to provide a lot more data, indicating that the Japanese version of the NRC(NISA) will be doing more and more direction of what is happening. http://atomicpowerreview.blogspot.com/ see the topic NISA instructs Tepco to report.
"There is now concern that the spent storage pool for reactor #4 is leaking."
That's a virtual certainty given they're dumping a hundred of tons of water in every day (iaea.org). As is the *fact* that at least some of the fuel rods in that pool are damaged, though we don't know to what extent.
When I first heard about this disaster in Japan my first reaction was that I felt bad for them. When I read this, learning about how far the radiation spread, how can those people be in the middle of the radiation and not evacuate with the others?? The workers at the plant are very brave, but I would like to know if they are being affected by the radiation? Also how do the people who were forced to evacuate deal with the shock, and where do they go for radiation free water or food? I thank you greatly for this amazing post, it really went deep into the problem and provided information the news doesnât.
Japan is in a tough situation at the moment and proble will be for a while. They should have made back up stuff to help Japan incase something like this happen but they werenât that smart. If they didnât have others help they wouldnât make it no way. They will get back up but it wont be for a long time.
I found this very interesting to read about. How are the people in the radiation zone getting fresh water to drink? How are the people working in the plant being protected from the radiation?
Japan is in a very sad situation now. I didnât know what to think when I first heard about the disaster. I couldnât imagine how scared the people there feel, especially the people in the plant. I think other countries should help Japan through these hard times they are in. I donât know how any of these people are getting fresh water for themselves and their whole family.
Greg, I'm surprised that you present "thousands died and/or got cancer due to Chernobyl" as an extreme anti-nuclear position. I think everyone accepts that thousands of children got thyroid cancer, and as I am probably one of the "Nuclear Power Apologists", I'd expect to be citing lower numbers than you. By contrast I have not seen anyone claiming that Chernobyl's effects were limited to the site, even if some point to opportunities that were missed to mitigate the off-site impact.
For a real extreme anti-nuclear view, you should probably check back with Helen Caldicott, who clearly believes in large numbers - but be careful not to get "ratcheted". Just because she says these numbers doesn't make them plausible.
I'm glad you appreciate the importance of evidence in the "continuing fission" myth - short half-life elements are indeed the main evidence to look for.
I'm depressed to see the mistakes of exaggerated risks starting to be repeated in Japan. The UN report on Chernobyl was clear that this was and is a major depressive effect on the health and recovery of that region.
Joffan, don't let your own calibration of what extreme polarized beliefs are vis-a-vis my calibration of them be even a slight distraction. There is no point whatsoever in doing that.
I also would be very interested in seeing how a court would find the planning decisions prior to this disaster
Just wanted to point out that the piece posted about 'radiation dose density' is a big pile of bollocks. Not blaming you, you are just posting links (I assume to promote discussion) but readers should understand it.
The sievert measure described does weight for type of radiation (despite the implication in the article that it doesnt) - for example a alpha particle is considered 20 times more damaging than a beta
The sievert measure is also weighted for specific tissues, so radioiodine that is likely to get into the food chain is statistically weighted to the thyroid because that is where it goes, and the thyroid is radiosensitive
The tag line of the article at the end "we need to modify measures for internal exposures" is ridiculous. That is what they are, you science-impaired retard! An alpha particle cannot harm the body at all from the outside (cant make it through the dead skin layer) but we consider them 20 times as damaging as other radiation sources! Cant explain that, right?
Secondly, dose rate, below the level for deterministic effects (like skin burns, like sunlight!) has almost no relationship to cancer risk. Lifetime risk is equivalent to all the additions of risk.
The threshold for deterministic effects is around 2 Sv. We are talking doses currently in microSv levels, that is, millionths of a Sv.
And even after all that, the whole discussion is bollocks anyway. There are no alpha particles affecting people currently. We have gammas and betas, all of which have the same proportional effect on the body as xrays. People would have to eat uranium or plutonium to have any chance of meeting alphas, and there is currently no chance of that, unless they are licking a few very localised puddles on site at Fukushima
The author of that article clearly has no understanding at all of what they are talking about. It is rubbish. I hiope it is clear this is not the dreaded "nuclear apologising", but simple science. The authors of those articles are just wrong. As wrong as saying dolphins are fish.
I am a medical doctor who is trained to understand radiation risk to people, by the way
You are right to an extent; "Relative Biological Effectiveness" weightings (RBE) are applied to internal alphas. In a 500 word article I didn't have space to acknowledge that. My point stands nonetheless, because the RBE of 20 is based on the very crude issue of cell killing. Cell killing is largely irrelevant, since dead men tell no tales. The cells that concern radiation protection are the potentially mutated survivors which to a large extent are the ones of the edge of the killing zone. In addition, the killing zone can be a hollow sphere, due to the Bragg effect caused by the deceleration of the alpha particle as it runs out of energy. This means that the highest dose density is at the end of the track and furthest from the Uranium or Plutonium particle, so there's a shell of dead cells; inside that shell less damaged cells are isolated from the communal cell signalling which is thought to mediate apoptosis or cell death. This is a scenario for rogue colonies running out of control. In addition (and separate from the Bragg effect) epigenetic effects in which unirradiated cells manifest the symptoms of having been irradiated define a massively larger target for radiation than is conceived by the very simplistic conventional model. The sievert gets nowhere near this level of information so my basic point is valid.
Tissue weightings are even less informative that RBEs.
The paragraph where you refer to me as a science-impaired retard seems to be making some point about a 20-fold RBE not being needed even for alpha particles. The RBE only applies for internal alpha emitters, where there is no dead skin layer to consider.
My article referred to dose rate only because the Guardian's Readers' Editor had made that point, including the analogy of sunshine and skin burns. That was my way into the topic - in a "Response" column you have to have something to respond to. I think I have shown how dose density is more important than dose rate.
You make a point about a 2Sv threshold for deterministic effects. I agree, we are talking doses currently in millionths of a Sievert as conventionally modelled. The emphasis is on "as conventionally modelled". ICRP would model the dose from alpha decays across the whole body. The whole body dose from a single alpha particle track is 0.000000000005milliSievert (mSv) but the single cell which is the actual target gets 500mSv. It is the dose to the cell that causes genetic damage and, potentially, disease.
Your assertion that alpha particles are not affecting us could not be more wrong. Since the accident Uranium has been found in air filters with a trend for distance from Japan, all the way across to California. Inhalation is more hazardous than ingestion. The people of Japan are certainly exposed to both pathways (inhalation and ingestion) though as far as I know nobody is telling them anything about the quantities of alpha emitters in their environment.
You are ridiculous if you think the ICRP models alpha radiation doses across the entire body. That is totally incorrect. They model the doses to specific tissue based on the method of intake (inhalation v. ingestion), chemical solubility in those tissues, particle size, etc. They then derive a committed dose equivalent (dose received after 50 years).
Next they compare the cancer risk from that localized dose to a whole body dose equivalent. That is done so a total effective dose equivalent (internal plus external doses) can be summed.
But they never model alpha doses across the whole body.
Heatlhphys, please try to avoid the ad hominem. If you'd like to provide a current reference to what you claim the ICRP says and does, that would be nice. At the moment we have a qualified expert on the topic with a real name vs. some guy on the internet who makes unverifiable claims about his expertise but who has shown a number of biases so far. You could (possibly) easily make your point with evidence. Otherwise, you haven't made it.
What I have posted can be found in any textbook on general health physics. Try Contemporary Health Physics by Bevelacqua or Introduction To Health Physics by Cember found on Amazon:
A primer from Bevelacqua's book can be found here:
The ICRP publications are not free, but can be found here:
The publications upon which most countries' regulations are based for internal dose are Publications 26 & 30, discussed in Bevelacqua's primer.
The NRC discusses some of this in Appendix B to their radiation safety regulations found here:
Bob Applebaum, Certified Health Physicist
Bob, I could have thrown up a bunch of possibly relevant links as well. Telling us "everyone knows this, its out there, here's a few links you can't access and 60 pages of tables in a PDF file" is little more than circumstantial evidence that you can't really back up what you said. Is that the case?
This is highly technical stuff and almost totally inaccessible literature. What I'm seeing here in your comment is a smoke screen, but I'm sure that is not what you intend.
Now, give us a citation that means something and don't expect us to just take your word for it. Like, for instance, a quote or two or a paraphrase with a reference to a page or two in a document someone can see.
Or, not. You don't have to do our homework for us. But in this particular debate, I'm not trusting experts (on either "side" of this artificially polarized field of argument) because there is too much denialism and apologist-ing going on here.
No smoke screen. And I've only commented on and am denouncing the claim that the ICRP averages alpha doses over the whole body.
You should be able to see that that is completely wrong by going to the Bevelacqua primer, page 7 of 11.
See Eq. 25 & 26? See "where w(t) is the ICRP 26/30 organ/tissue weighting factor" as well as Table 6?
If an alpha emitter were inhaled, the dose would be localized and would be largely calculated over the lung. That is what H'(50,T) represents in Eq. 25 & 26. The "T" represents specific, irradiated Tissue, not the entire body. The "50" refers to what I said in a previous comment about 50 years.
In order to compare the cancer risk of this dose to an equivalent external whole body dose a lung tissue weighting factor is used. That is the w(t) in Eq. 25. For lung, the value is 0.12, from Table 6.
Thanks to hp for the links while I was sleeping. I think that last by Greg was not sarcastic?
To Mr Bramhall, I honestly never expected you to come here, and to be honest I would have been a little more diplomatic if I had known you would, although I stand behind what I have said. I will say you do sound less 'science-impaired' in your post here!
Cancer generation is a stochastic phenomenon. This means in large scale systems like human bodies the exact 'how' of radiation deposition is almost irrelevant. If you can link me to any literature that shows a 500mSv dose to a single cell means sweet FA I will be glad to back down here, but it doesnt.
Dose levels are considered across the tissue or body, because statistical likelihood means next to nothing for a single cell.
To illustrate the current understanding is there is a 5% risk of cancer per sievert of whole body dose. By your thought process if I understand it, a single cell being hit by an alphas particle should somehow equate to a 50% risk of cancer in that cell, or at least a higher risk than the current standards predict, because it recieved half a sievert.
This is demonstrably untrue. Radiologists performing interventional procedures can recieve 100s of millisieverts to their arms, but have essentially no change in cancer risk. That is just one example.
Cancer risk, as a statistical model, only works by invoking whole body doses. If you get a smaller area irradiated we use tissue weighting factors to convert that to a whole body dose. It is a statistical model, that simply says "if this much [tissue type] gets irradiated, this much cancer will be caused across a population.
All of the data supports this method, and the governing bodies update the tissue weighting factors as more evidence emerges.
To try and take a probabilistic model and say it is wrong because it doesn't describe individual particle interactions is like doing a large cohort study and then dismissing it because it doesn't describe "anecdote A".
I will just add that your explanation of RBE is wrong. It is not based on cell killing, even if that is sometimes how it is tested
It is based on linear energy transfer (LET) - the amount of ionising energy the particle deposits over a certain length of material. This is actually the exact concept you are talking about - the energy density of the radiation
Most of the time this is proportional to cell death, but also cancer risk, which is why we use it. An alpha deposits 20 times as much energy over a short distance than a beta or gamma, so they are biologically more dangerous. 20 times more dangerous. For cell death AND cancer
So what you are concerned about is already taken into account
no body wants to go all 'henny penny' on this thing, because the nuke industry has many powerful friends. and too many people all over the world live too close to too many reactors.
Fortunately I heard that these accidents rarely happen, and when they do its all ok. For instance, I read about one of the japanese workers saying it was all ok, because after he put his raincoat on, and went into the heavily leaking reactor, when he came out, they washed it all off?!?!
Doesn't that sound just like the guys who watched the atom bomb tests just turning their backs on the blast (because the flash was so bright), then waiting a few moments before turning around (while wearing protective cotton shirts and shorts.
Haven't we come a long way? We are just really lucky that they have solved that pesky nuclear waste issue once and for all!
So my question is how much of japan will be irradiated? I dont know much about japanese agriculture, but how will they be affected in that sense?
I was just at a conference on hormesis this week. There was a lot of discussion of radiation hormesis.
The premise of the LNT model is that there is no DNA repair (known to be false), and that dose rate has no effect, only the total integrated dose (also known to be false).
Many of the physiological changes that occur during radiation exposure (induction of antioxidant defenses and DNA repair enzymes) also occur during other types of stress including exercise and exposure to things like resveratrol.
What you are stating about the LNT is not quite correct. The LNT model is a macro view of dose versus response. The underlying details are irrelevant. Either a response (cancer induction) increases linearly with dose or it does not.
The best model which fits this macro view is the LNT. BEIR VII investigated this...they considered DNA repair, and dose rate effects and hormesis, and still concluded the LNT is the best model of response versus dose.
I was just at a conference on hormesis this week. There was a lot of discussion of radiation hormesis.
The problem with LNT is that it is an extrapolation, not an interpolation.
There are multiple things going on, and the baseline is not zero. When the treatment (radiation exposure) both causes damage and induces repair of damage, the net after damage and after repair is not a linear combination because the underlying phenomena are non-linear.
What physiology is linear over multiple orders of magnitude? If 50% of bones break at a 1000 pound load, do 5% break at 100 pounds? Do 0.5% break at 10 pounds?
2 billion years ago when organisms evolved these DNA repair enzymes, the K40 level was 10x higher.
What you are saying are good reasons to examine hormesis.
And when BEIR VII did so, they found the LNT model was the best model to describe radiation effects.
There is nothing you've said that they weren't aware of.
Daedalus, hp is right. Discussing hormesis is falling victim to the same problem Mr Bramhall seemed to - trying to create a rule from processes many orders of magnitude below effect
The equivalent is trying to build a theory of everything from scratch, and then testing it against 'everything'
The LNT model is simply a statistical approach to how much cancer seems to be caused by radiation, with a nod to erring on the side of caution. Anyone who works in radiation physics KNOWS that it is not the whole story, but in macro scales (like humans) it is a very successful approximation, that also works as a worst case scenario, because while the effects if radiation may be better, unless you are making some giant cognitive leaps like Mr Bramhall, it shouldn't be any worse