The effects of nuclear weapons. Credible nuclear deterrence, debunking "disarm or be annihilated". Realistic effects and credible nuclear weapon capabilities for deterring or stopping aggressive invasions and attacks which could escalate into major conventional or nuclear wars.

Thursday, August 25, 2016

Investigation of the Gamma Radiation Hazards Incident to an Underwater Atomic Explosion

ABOVE: Original Top Secret version of the BAKER nuclear test underwater burst fallout pattern (reprinted with ships positions deleted and less detail of hotspots in DASA 1251, the fallout patterns compendium), from Strope's Investigation of the Gamma Radiation Hazards Incident to an Underwater Atomic Explosion, a vital report listed on the U.S. Department of Energy website without a PDF; but they kindly scanned it in and emailed it to me last week, so it's now available for everyone to read and download on Scribd and also at Internet Archive,

We have uploaded to Scribd and Internet Archive a PDF of Walmer E. Strope's brilliant classic, originally classified March 1948 report deriving the 25 July 1946 CROSSROADS BAKER underwater nuclear test fallout and base surge dose patterns from the raw data (dose rate meters, film badge doses and films of the fallout plumes being deposited on the various ships or passing by them), Investigation of the Gamma Radiation Hazards Incident to an Underwater Atomic Explosion, U.S. Defense Nuclear Agency document DNA-6032F-C.8.4 and NNSA/NSO Nuclear Testing Archive report NV0048674.  This 110 pages report was kindly scanned and emailed to me by Nevada NNSA.

Although the fallout dose rate pattern for 1 hour after burst extracted from this report has been published before, the detailed information in it is vital to determining accurately the accumulated doses which depend on the arrival times of the fallout.  Strope discusses how he researched the report in his recent 32 chapter autobiography, Autobiography of a Nerd.  Fallout arrival times and integrated doses are vital for determining the ability to evacuate or shelter from the fallout in a terrorist event, like an improvised nuclear device detonated inside the cargo freight of a ship, off the coast of a city.

Jerry Strope (Walmer E. Strope), Autobiography of a Nerd, Chapter 6, At The Crossroads (pages 79-92):

"We met at Union Station on the cold gray Sunday morning of April 28, 1946, more or less prepared to ride the train across the country to San Francisco, where we would board the USS Wharton for the voyage to Bikini Atoll in the south Pacific. In addition to myself, there were the staff of the Ship Protection Section of Preliminary Design: LTC Dave Savaker, Henry Cochrane, Woody Armstrong, Charlie Ksanda, and Ken Lovell. With us were engineers and technicians from other parts of Buships, mostly strangers whom we would get to know well in the next six months. Forty or fifty strong, the Buships contingent to Operation Crossroads left Washington knowing little of what was to come. ...

"... During the spring of 1947, some of the results of the radiological measurements on the ships at Bikini began to come in. ... . I laid out a plot of the target array on my drafting board and began to plot the raw measurement data. I wasn’t quite sure what I was looking for but I knew what it was when I found it. Some of the ships showed higher readings than ships closer in to the burst. This should not have occurred if the base surge was the contaminating mechanism. I called the anomaly to Muddy’s attention. After some discussion, we decided to pursue the matter further. We needed the film badge data from the target ships, which would give us the total radiation exposure to compare with the contamination measurements. The film badge data for some reason were Top Secret. So we applied for a Top Secret clearance. Meanwhile, I began to refine the contamination data by adjusting to a common measurement time. ...

"All that summer I worked on the contamination patterns from the Crossroads underwater shot. I obtained dozens of photographs of the event: the luminous bulge, the white stem of water rising, the cauliflower cloud forming, the base surge at the foot of the collapsing column and the pendulous plumes dropping down from the cloud onto the ships in the target array. Some amateur photogrammetry proved that the location of these plumes matched the areas of high contamination measurements. I was convinced that most of the contamination came from the cloud fallout and not from the base surge. (I liked the word ‘fallout’ and was one of the first to use it.) ... Labor Day 1947 came and went. The Top Secret clearance seemed bogged down somewhere. Finally it arrived on the third of October. I requested the film badge data. ... The film badge data arrived. It confirmed my analysis of the contamination measurements. Moreover, by analyzing those target ships that were not under a fallout plume but were enveloped by the base surge, I concluded that over 90 percent of the radioactivity had come from cloud fallout and less than 10 percent from the base surge. We put the report to bed in January of 1948 and it was distributed as a Bureau of Ships classified report in March of that year. It bore one of my typical grandiose titles: Investigation of the Gamma Radiation Hazards Incident to an Underwater Atomic Explosion."

UPDATE: 31 August 2016

NATURE OF THE RADIOACTIVE DEBRIS AND NUCLEAR RADIATION ASSOCIATED WITH AN UNDERWATER NUCLEAR EXPLOSION, Secret - Restricted Data, DASA-1420, report 0117443[377394], uploaded to Scribd and also to Internet Archive

This comprehensive, formerly Secret-Restricted Data report by U.S. Naval Radiological Defense Laboratory staff Edward A. Schuert (who proved the validity of the hand fallout forecast at four hydrogen bomb tests of Operation Redwing, Bikini Atoll, 1956) and Louis B. Werner (the chemist who isolated plutonium for the first time in World War II), was kindly scanned and emailed to me by the NNSA/NSO Nuclear Testing Archive, which had the report's description but no PDF readily available on its database:


Above: In the previous post we examined how hard left wing fear mongering anti deterrence and civil defence hatred promoters have been promoting racist multiculturalism in the way Stalin and Hitler did.  Unless we get a handle on dealing with those who rant and promote dishonest agendas, progress will not be made to tackling terrorism by means that have been tried and tested at great cost.


At 12:06 am, Anonymous Anonymous said...

Although it is not relevant to this particular post, I would like to know your estimate of the average ground ranges after blast attenuation, for 1,2,5,10,20,and 50 psi, in a modern urban area, for a 200kt surface burst. I have also noticed that the ground range for severe damage to residential construction is 70 ft for a 1t V-2, but about 9000 feet for a 1 Mt burst at optimal height. The area scaling factor (~16000) exceeds that expected from cube root scaling and blast efficiency (6300) by a factor of two or more. Part of this is that effects such as regular reflection can be used to maximal effect when the shock front is large compared to buildings, personnel, etc. Part of the discrepancy is owed to positive phase duration. This parameter is not all that important when comparing a 1 kt and 1Mt burst, but for yields below 1 kt, the inertia and elasticity of the target become progressively more important. The departure from cube root scaling can only be expected to get worse and worse for yields below 1 t. In practice, some of the higher yields advantages are lost due to shock arrival time, and when attacking many small targets, or irregular targets. Even so, this worst case scenario predicts around 32000 blast fatalities from a 1 Mt burst at optimal height (regular reflection ends at 9000 ft) over a city such as 1940's London, and duck and cover could reduce this to 15000. This is far fewer than most people would estimate. Thank you for writing this blog. It helps to undo the confusion caused by claims that an ERW "leaves buildings standing", or that "conflagration" will occur at 10 km from a 1 Mt airburst. Essentially, area weapons cannot go after individual people, and their effects cannot make decisions. They swamp an area, and a jacket thrown over the head may protect against an otherwise instantly lethal 50 cal/cm2 in a manner far more effective than the mighty Maginot Lines. Few people realize these kinds of things, or that knowing and practicing them actually helps discourage the outbreak of war and the use of nukes.

At 10:29 pm, Blogger nige said...

200 kt surface burst on a modern city? I thought 200 kt surface bursts were reserved for missile silos! Why this particular scenario? Why not 2 kt neutron bomb on tanks crossing a more rural border, or as this post argues, the more plausible threat of an improvised terrorist bomb in a ship offshore.

Please Robert Harney, associate professor of systems engineering at the Naval Postgraduate School, "Inaccurate Prediction of Nuclear Weapons Effects and Possible Adverse Influences on Nuclear Terrorism Preparedness", Homeland Security Affairs, 5, Article 3 (September 2009). which roughly treats the city skyscraper skyline by analogy to an explosion underground in a canyon, and concludes:

"Although the models used above for surface bursts are first-order and do not take all possible phenomena into account, the author is confident that the effects for a real explosion will be much more limited than those predicted by the flat-surface burst, and the flat-surface burst is known to be much less damaging than an optimum altitude airburst. Better models for nuclear effects prediction in urban environments may produce somewhat different estimates. Such models should be developed and made available to emergency planning groups. The models should include not only the effects on structures, but also estimates of the injuries and fatalities that might result."

Harney's model is basically just saying that a surface burst in a city increases cratering effects (damage to buildings being treated as terrain) at the cost of thermal and blast effects, but is a very crude and doesn't take account fully of the cumulative blast attenuation that occurs as energy is used up as the blast sweeps outwards, damaging successive structures, and was criticised in that journal. Yet the fact is that William Penney demonstrated at Hiroshima that even single story wood frame buildings absorb energy in being destroyed in a cumulative manner with distance, causing an exponential additional drop in peak overpressure by an attenuation factor of exp(-R/3.25) where R is ground range in units of km.

At 10:30 pm, Blogger nige said...

In other words, due to energy loss in causing damage to Hiroshima buildings, the peak overpressure at 3.25 km ground range falls by a factor of e (about 2.718281828..., easily remembered as 2.7 followed by 1828 twice over) of that for a similar weapon burst half the Nevada desert (unobstructed terrain). This is something that is well documented in the many tables of carefully determined blast pressures compared to unobstructed surface nuclear tests, of Penney's 1970 report "The Nuclear Explosive Yields at Hiroshima and Nagasaki" (by Lord Penney, D. E. J. Samuels and G. C. Scorgie), Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 266, No. 1177 (Jun. 11, 1970), pp. 357-424. I've plotted these key data graphically, on this blog.

It turns out for the housing density of Hiroshima that each house in a radial line from ground zero, in the Mach region where the blast wave moves horizontally through and over successive buildings as it diverges (not the first wave in the regular reflection region, where in an air burst the blast is coming directly downwards through free air from the burst point, and thus not intersecting buildings on the way, unless they are very tall and close spaced), each wood frame house causes a fall in peak overpressure of 0.9%. Now you can simply scale this observation to modern concrete buildings. Remember that the key source is blast energy loss in this way is not broken windows but the displacement of the whole buildings as it is pushed, which is simple to calculate and scale for: if a force F pushes the centre of mass of a building the distance X in the direction of the force, the energy E absorbed from the blast wave is simply E = FX Joules. Thus, if you increase the size and mass of the building, it's child's play to calculate the effects. See Charles Bridgman's DTRA "Introduction to the Physics of Nuclear Weapons Effects" (I've long ago reviewed the relevant section on this blog, with the calculations for a specific but fairly typical concrete building absorbing energy at 10 psi peak overpressure).

I disagree with your claim that cube root scaling is wrong below 1 t yield. On the contrary, the exponential attenuation factor for blast in cities makes Glasstone and Dolan completely wrong for higher yields in cities. Low yields do scale as cube root for pressure. The exponential city blast shielding factor (caused by energy absorption by buildings) breaks the cube-root law for high yields.

Just as attenuation stops the neutron radiation energy per unit area distances from scaling as strongly as the square-root of yield (which would occur in a vacuum), so the exponential attenuation of blast energy by buildings stops the blast pressure ranges from scaling as the cube-root of yield.

The yield dependence on blast pressure ranges in a city is a much weaker function than cube-root. In addition, for people taking cover, the longer duration at higher yields blows debris over a wide range, reducing the debris load falling vertically on people taking cover under desks or tables in a building. The 9/11 tower collapses were vertical, maximising the load falling per unit area. A high yield blast will blow debris down range, producing a far more uniform distribution of debris than occurs when conventional bombs with short blast duration demolish buildings. Provided people are lying flat under strong tables, they will have a better chance of survival than when the entire load of a building collapses vertically on top of them.

At 10:55 pm, Blogger nige said...

If you meant that impulsive damage for buildings is more important than peak overpressure at very low yields, then that is true. That's another error Glasstone and Dolan 1977 make. If you look at the blast effects on buildings monographs, you can see that the first edition dated 1957 gets the physics right: drag sensitive targets like aluminium aircraft sheds have a damage range that scales as the 0.4 power of yield below about 1 Mt but the lines curve and revert to cube-root scaling (0.333... power of yield) above 10 Mt. Also, it is cube root scaling for threshold damage effects like window breakage or cracking concrete walls, which require a minimum force per unit area (overpressure fixed, regardless of duration).

If you sit on a chair or stand on a roof or lean on a wall, the pressure exerted is your weight or force (force F = Ma) per unit area. If you exert enough pressure to break it, it breaks. If you exert half the pressure needed for twice as long, or even a million times as long, it does NOT break. Hence, the duration of the pressure is irrelevant.

Impulse, pressure integrated over time, is therefore not important for the threshold pressure needed for cracking things. It's ONLY relevant for far more severe damage, such as blowing away buckled wall panels, as in the 1956 Cherokee blast demolition of aircraft hangars: once the blast pressure exceeds that needed for permanent distortion, the duration does start to have an effect. In other words, severe damage is a function of time (impulse), but threshold damage (the onset of permanent distortion) is NOT a function of time, merely dependent on a peak pressure. The American nomographs became confused in Glasstone 1962-77 after the 0.4 power of yield scaling was adopted empirically as a dogma, after a classified AFSWP report that used jeep displacement data from Upshot and Castle Nectar, simplistically correlated the data using 0.4 power of yield scaling (that 0.4 power of yield report is: "Damage to Military Field Equipment from Nuclear Detonations", AFSWP-511, April 1956; Secret Restricted Data).

At 9:13 pm, Anonymous Trevor said...

How extensive is long-term radiation from surface bursts? I was reading about isotopes like Cesium-137 and Strontium-90 that can supposedly stay active and dangerous for a couple hundred years. Not enough to cause acute radiation syndrome, but enough to greatly increase the risk of cancer over time.

If we did have a nuclear exchange and they got into the soil around a significant portion of our farmland, how severe would the effects be? I know even a total exchange isn't a world-ending scenario, but something like that could certainly cause us a lot of difficulties.

At 3:12 am, Anonymous Anonymous said...

I know the range for a given peak overpressure scales with the cube root. What I meant to say was that the overpressure for a given level of damage rises if the duration is short.Any object, be it a person, an I-beam, or a window, has the two properties of mass (and therefore inertia) and elasticity. This can be easily proven for a window pane. If you see a reflection in a window and gently push on the center, the reflection will become distorted. This is due to the glass bending, and should reverse when you let go. Even a 20 psi shock wave will not truely crack a window immediately. First, it would have to overcome inertia, as per Newtons second law A=F/M, and then push it beyond its elastic limit. Admittedly, the would happen rather quickly, but not instantaneously. All targets have both a minimum peak overpressure for damage, and a time dependant property. If the peak pressure is low but long lasting, the elastic deformations will return to normal as the positive phase ends. If the peak pressure is high, but falls to zero too rapidly, there may be a damped oscillation in the target, but no permanent deformation , cracking. As the duration increases, the pressure needed for damage falls, but only up to a certain point. No matter how long it lasts,the pressure will not do damage unless it is above a certain value. If a V-2 with .002 kt equivalent yield airbursted at 96 feet (760 scaled), both regular reflection and 15 psi would reach out to 113 feet on the ground. However, the damage would be nowhere near as bad as at 9000 feet ground range for 1 Mt at 7600 ft HOB. I'm only writing in terms of regular reflection, because I do not know how extensively a mach wave would be attenuated by trees , buildings etc. Atennuation is a fa scinating and important topic, but no one has a good formula for it. Because of this, it is often ignored. I can only assume that the effect is greatest for high yield ground bursts. Nonetheless, the Defense Civil Preparedness agency's "What the planner needs to know about fire ignition and spread" states that 10 psi would extend to over three miles from a 5 Mt ground burst in Detroit. Similarly, the popular website nukemap fails to show any airblast attenuation, and incidentally says that dry wood ignites at 35 cal/cm2 ,although no atomic test data supports this claim. Bridgman's book comes close to predicting attenuation, calculating the energy absorbed by a single building in open terrain at an overpressure where it is not badly damaged. Assuming Penney's e^-R/3.25 equation held true independant of yield and burst height, and assuming that mostly wood buildings were in Detroit (probably not true), then only around two and a quarter psi would be present at the distance where the DCPA predicts 10.

At 12:46 am, Anonymous Anonymous said...

what I meant about cube root scaling breaking down at low yields is that if you lower the yield, for instance from 5Mt to 5kt, a structure might need 10 psi for threshold structural damage. This would happen at ~16000 ft in open terrain for a 5 mt burst, and ~1600 ft for a 5kt burst. However, this trend only holds up to a point. For a 5/8 lb burst, 10 psi might reach out to 8 ft, but that 10 psi will fall to lower pressures so rapidly that the walls will barely start to deform (distortion is delayed by the buildings inertia and elasticity) by the time the overpressure decays to zero. The 5 mt scenario is from the DCPA's "What the planner needs to know about fire ignition and spread", and using Penney's data (for now ignoring building type and non linear scaling) it is easy to compute a peak overpressure of 10 e^-4.87/3.25=~2.25 psi. Even so, this may cause failure of certain targets (eg. windows) that would fail to be damaged by 10 psi of a very short duration. Bridgman's analysis only calculates the energy absorbed by a building, but ignores the fact that exerting a sustained drag force on even a perfectly rigid building requires a use of kinetic energy, which becomes dissipated as heat which is nowhere near as effective at sustaining the shock wave. Also, a result such as 2.6 mj is useless without details on how much energy is present near the ground as air blast. For instance, if we assumed that all of the energy were directed to the buildings near the ground, A 10^14 j burst could produce these effects on >10^7 buildings of Bridgman's type. Thankfully, this is not the case. At least this was an attempt to calculate the blast attenuation, while others such as the DCPA may be overestimating pressures by a factor of four or more, especially for high-yield surface bursts.

At 3:23 pm, Blogger nige said...

"Also, a result such as 2.6 mj is useless without details on how much energy is present near the ground as air blast."

You simply don't know what you are talking about! We know that from simple geometry and the physics of shock waves. The energy density at every point in the blast wave is a simple function of the overpressure and the dynamic pressure. Therefore, it is very easy to do calculations of energy absorption! It's been very easy since Penney's paper was published in 1970! There is nothing complex about this. You are obfuscating. Even Glasstone explains that the dynamic pressure is basically the kinetic energy density of the blast wave, while the overpressure is related very simply to the non-kinetic (i.e. thermal) energy density of the air. I have a paper on vixra (my first paper submitted there) which goes into the physics, and you can also find these equations explained well by Philip J. Dolan in an appendix to the 1972 "Capabilities of Nuclear Weapons" which I've uploaded to Internet Archive!

By the way, the quotation I gave from Walmer aka Jerry Strope needs a footnote: Bikini Atoll is of course 11.6 degrees NORTH of the equator and thus is in the NORTH Pacific, not the South Pacific.

At 2:56 pm, Blogger nige said...

Regarding the comment on long lived Cs-137 and Sr-90, there are many posts on this blog documenting easy solutions and nuclear test research on the subject. See: for a summary by Dr R. Scott Russell and others of official British nuclear testing research applied to nuclear war, which concludes that Sr-90 and Cs-137 are no problem.

The simple fact is that the uptake is so small from soil to plants and animals, that the dose you get is insignificant compared to the early gamma fallout dose you get in the first hours following the explosion. They cite as an example an area where the external gamma dose rate is 100 R/hr at 1 hour after burst, plus global fallout from 5000 fission megatons, which gives a total of only 2 rads to the bone marrow.

That's so low in the hormesis region for the very low dose rates involved, in other words, no deaths, and possibly just a stimulation of your P53 DNA repair enzymes which reduces the natural cancer rate. (See the 2010 Springer published book by Dr Charles L. Sanders, "Radiation Hormesis and the Linear-No-Threshold Assumption",

Additionally, even in hotspots of heavy fallout around the bomb crater, you can do things to avoid uptake of cs-137 and sr-90. Remember that cs-137 is taken up from the soil if it is deficient in potassium and for crops that need potassium, while sr-90 is taken up where the soil is deficient in calcium that the plant needs.

Also, calcium is a structural element in plant stems, just as it is used to harden the protein in our bones. If you eat potato leaves you get sr-90 (more important, you get solamine poisoning, since potato leaves and stems contain the poison solamine), but there is no significant natural solamine poison or sr-90 in the actual root tubers, the potatoes themselves! Being in the ground, they don't need calcium and sr-90 to hold them up, unlike leaves and stems.

So plant potatoes in sr-90 contaminated soil, since the starch in the potato contains insignificant sr-90. Don't plant lettuce or cabbage in sr-90 contaminated soil, because any parts of plants that are hardened by calcium, like leaf veins and stems, will contain calcium and sr-90 which is chemically associated with calcium.

Better still, put "lime" (calcium carbonate, chalk, etc) in the soil to increase the ratio of calcium to sr-90, which reduces uptake. Or simply plant leaf crops in naturally alkaline (calcium rich) soil, e.g. soil in chalk or limestone bedrock. Plant potatoes in acidic soil with little lime. It's just common sense.

Regarding cs-137, I've blogged this before. Bikini Atoll is coral (calcium carbonate), so the calcium to sr-90 ratio is enormous, blocking any significant uptake of sr-90 by plants!

So at Bikini atoll, only Cs-137 is important. LLNL researchers found that adding potassium chloride to the Bikini soil reduced the uptake of Cs-137 in food by a factor of 20. In any case, it's generally insignificant compared to naturally radioactive potassium-40. Because cs-137 is associated with potassium chemically, it's uptake is highest in foods that contain a lot of potassium but grow in potassium deficient soils like coconuts at Bikini atoll. The main problem is the coconut crab, which concentrates cs-137 by eating coconuts that are already concentrating cs-137. However, you can still eat a tree climbing coconut crab every week without any significant risk compared to normal background radiation from K-40.


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