Peace through practical, proved civil defence for credible war deterrence
  • Please see our post on the need to deter not only direct threats from nuclear attacks but also conventional wars and invasions that can escalate into nuclear wars (as proved by the use of nuclear weapons in WWII, for example, after they were developed during the war itself and did not trigger or provoke the war), linked here and here, and the true scaling law equivalence between a few thousand nuclear weapons and the several million tons of small conventional weapons in a non-nuclear world war as proved by our post summarising key points in Herman Kahn's much-abused call for credible deterrence, On Thermonuclear War, linked here.

  • Hiroshima's air raid shelters were unoccupied because Japanese Army officers were having breakfast when B29s were detected far away, says Yoshie Oka, the operator of the Hiroshima air raid sirens on 6 August 1945...

  • In a sample of 1,881 burns cases in Hiroshima, only 17 (or 0.9 percent) were due to ignited clothing and 15 (or 0.7%) were due to the firestorm flames...

  • Dr Harold L. Brode’s new book, Nuclear Weapons in ...

  • 800 war migrants drowned on 22 April by EU policy:...

  • Photographed fireball shielding by cloud cover in ...

  • Nuclear weapons effects "firestorm" and "nuclear w...

  • Proved 97.5% survival in completely demolished houses ...

  • Saturday, November 01, 2008

    Underwater nuclear weapon test effects







    The fallout data measured by George R. Stanbury and others from the British nuclear test in a simulated terrorist ship attack, Operation Hurricane, is linked here, and it was used in 1954 by Stanbury to assess radiation hazards in the restricted U.K. Home Office civil defence report, "Assumed Effects of Two Atomic Bomb Explosions in Shallow Water Off the Port of Liverpool," CD/SA51, U.K. National Archives report HO 225/51. Stanbury used a contamination arrival time of 5 minutes, assumed that the population outdoors would take 2 minutes to move indoors, and used an average protection factor of 100 for buildings to allow for radioactive rain to run off roofs and into underground drains or soak into the soil. He concluded that two 20-kt bombs detonated in cargo freighters 180-m off shore at lunchtime when 20% of the population is outdoors, on lunch breaks, would kill 78,600 by blast and by the radiation if the wind was blowing inland at 10 miles/hour.  The initial radiation is reduced for the Hurricane bomb-in-ship burst, and only 1.8% of the yield was radiated as thermal radiation because the water cone thrown up rapidly quenched the fireball.  The main problem is the rapid arrival time of the fallout from such a low yield near surface burst, which leads to incredibly high radiation doses in a small "hotspot" area directly downwind.  (For the 15 megaton Castle-Bravo test, the maximum measured fallout doses in the hotspot areas were actually far lower as explained in weapon test report WT-915, because of the decay which occurred during the longer arrival time due to the higher mushroom cloud.  Measurements from automatic recorders showed that fallout from Castle-Bravo began to arrive under the mushroom at a mean time of 28 minutes after burst and the dose rate only peaked at 65 minutes after detonation, so people in a real city would have had a relatively long time to organise and evacuate from the hotspot area directly downwind.)  The shorter arrival time from the lower clouds of lower yield detonations gives less time for evasive actions like evacuation and sheltering.




    "... no weapon has ever had such potentially widespread and serious psychological aspects, nor has any weapon ever been used in war which has offered such rich opportunity for exploiting fear of the unseen and of the unknown." – Operation Crossroads: Radiological Decontamination Report of Target and Non-Target Vessels, XRD-185-87, vol. 1, p. 1 (1946).

    “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. ... 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 ... 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 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. ... 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.) ... 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 Hazard Incident to an Underwater Atomic Explosion [reissued by the U.S. Naval Radiological Defense Laboratory, Hunters Point, California, in November 1963 as report USNRDL-TR-687].”

    - Walmer E. Strope (1918-2010), Autobiography, Chapter 6: At the Crossroads, pp. 86-88.



    Above: a genuine colour film of the 23.5 kt Crossroads-Baker underwater test of 25 July 1946, detonated 90 feet (mid-depth) below the surface of the 180 feet deep Bikini Lagoon (it was suspended by cable from the ship LSM-60). From the colour of the mushroom cloud, you can tell that a lot of lagoon sediment been ejected upwards as the bubble vented. The underwater detonation creates an expanding bubble of compressed steam which, because of the relatively small depth of water compared to the bubble size in this case, scoured a crater in the lagoon bottom, resulting in a lot of sediment being thrown up with the water. The 180 feet water depth is extremely small compared to the 6,000 feet height of the mushroom cloud, so the effects are not typical of deep water detonations. This resulted in far more severe rainout of contamination than occurred in deeper underwater nuclear tests (away from the seabed) like Wigwam in 1955 and Wahoo in 1958.

    In some photos, you can see German and Japanese battleships within the white circular water shock ‘crack’, dwarfed by the ‘plume’. Thermal radiation was absorbed in the water, causing a steam bubble that vented in a hollow plume at 4 milliseconds. The white ‘crack’ is just water spray droplets knocked upwards at the surface by the water shock pressure. The ground shock, 13 km away, was merely a size 3 earthquake. The brief ‘Wilson cloud’ around the mushroom is an ordinary moisture cloud created by the drop in temperature behind the blast, in the 73% humidity lagoon air. The biggest transverse water wave to arrive upon Bikini beach, 5.64 km away, was 2.1 m high (crest-to-trough) at 5.1 minutes. (Waves approaching with 1.8-m height increased to 4.6 m in water 6 m deep then broke.) The mushroom subsided, to produce a misty ‘base surge’, emitting 4,000 R/hour of gamma at 2 minutes, followed by radioactive salt slurry rainout. Hosing and scrubbing ship decks at 7-16 days removed 50-80% of the radioactivity; the rest was chemically attached metal ions.
    The analysis of the radiation data for cloud head rainout and base surge transit exposure as recorded by radiation meters on ships was done in 1948 by Walmer E. Strope, Investigation of Gamma Radiation Hazards Incident to an Underwater Atomic Explosion, a classified document published by the U.S. Navy Bureau of Ships which was reissued by the U.S. Naval Radiological Defense Laboratory, Hunters Point, California, in November 1963 as report USNRDL-TR-687. It's not on the internet (the only articles by Strope that are online are here and here), but one good relevant online declassified report on underwater burst effects is:
    HANDBOOK OF UNDERWATER NUCLEAR EXPLOSIONS ( U ) VOLUME 2 - PART 2 (DELETED)
    This handbook, DNA 1240H-2 (March 1972), is particularly important for many reasons, giving a graph summarising all measurements of thermal transmission from land surface bursts in the Nevada and the Pacific, and giving data on water surface bursts as well as underwater bursts. There is also some useful data in the originally Confidential Capabilities of Atomic Weapons TM 23-200 November 1957, which gives the time dependent radii for the base surge for several depths of burst both in underwater and underground bursts based on nuclear testing with non-nuclear tests used to obtain scaling laws (the radii scale as the cube-root of yield; the times for corresponding radii scale as the sixth-root of yield or one-sixth power of yield), showing that in general the base surge for similar yields, burst depths and time after burst has a radius just over twice as great in an underground explosion in Nevada soil than in an underwater explosion (because of the difference in the density of soil and water and the difference in energy partition caused by the differing boiling points of the different media).

    We've blogged (in the 2006 Glasstone and Dolan post) about all of the history and technical details of the various updates to this manual to the present time. It started out in July 1951 as Capabilities of Atomic Weapons, TM 23-200, edited by Dr Gerald W. Johnson (Chief of the Analysis Branch, U.S. Armed Forces Special Weapons Project), and was a secret quantitative supplement to the more qualitative 1950 unclassified Effects of Atomic Weapons. Some 1,079 copies of each edition were published, and it was regularly updated with page changes as new information from testing became available. For example, the November 1957 edition includes an analysis of the effect of the blast wave "precursor" caused by desert sand popcorning into hot dust due to the thermal radiation flash on sandy soil, and also a brief mention of EMP effects on electronic equipment. Neither of these topics were even mentioned in the unclassified Effects of Nuclear Weapons until April 1962. In November 1964, the secret manual was revised and retitled Capabilities of Nuclear Weapons, and the Scientific Advisory Group on Effects (SAGE) was formed to edit revisions to the manual.



    Above: SAGE Panel in August, 1966.

    Capabilities of Nuclear Weapons originally started out as the 162 pages long 1945 classified Handbook on the Capabilities of Atomic Weapons, AD511880 (PDF version located here):

    “The purpose of this handbook is to set forth, in a concise and simple manner, criteria for estimating the effects of atomic weapons for use by the Services. It is designed to serve as a handy reference to aid Field Commanders and their staffs in determining the capabilities and effects of atomic weapons in respect to specific targets. The scope of this handbook includes thermal and nuclear radiation and blast effects of atomic weapons on items of military interest such as structures, materiel and personnel. These effects are analyzed with respect to Air, Surface, Underground, and Underwater Bursts. Sufficient information is presented to allow Field Commanders to determine the best type of Weapon and Burst to be employed to obtain maximum desired effects on various types of targets.”

    TM 23-200, Capabilities of Atomic Weapons, November 1957, was a single volume consisting of 441 pages in 12 sections divided into 2 parts (it has only about a quarter as many pages as Dolan’s 1651 pages long 2-volume 1972 revision DNA-EM-1):

    Contents of Capabilities of Atomic Weapons, U.S. Armed Forces Special Weapons Project, Washington, D.C., technical manual TM 23-200, November 1957, Confidential (declassified in 1997)

    Preliminary pages (22 pages consisting of title pages, distribution list, contents pages, page locator for physical phenomena figures and tables, and foreword)

    Part 1: Physical Phenomena

    Section 1: Introduction (13 pages)
    Section 2: Blast and Shock Phenomena (95 pages)
    Section 3: Thermal Radiation Phenomena (19 pages)
    Section 4: Nuclear Radiation Phenomena (87 pages)

    Part 2: Damage Criteria

    Section 5: Introduction (21 pages)
    Section 6: Personnel Casualties (20 pages)
    Section 7: Damage to Structures (54 pages)
    Section 8: Damage to Naval Equipment (15 pages)
    Section 9: Damage to Aircraft (11 pages)
    Section 10: Damage to Military Field Equipment (23 pages)
    Section 11: Forest Stands (15 pages)
    Section 12: Miscellaneous Radiation Damage Criteria (10 pages)

    Appendix 1: Supplementary Blast Data (32 pages)
    Appendix 2: Useful Relationships (10 pages)
    Appendix 3: Glossary (7 pages)
    Appendix 4: Bibliography (9 pages)

    Page 4 of this bibliography cites the report: J. F. Canu and P. J. Dolan, Prediction of Neutron-Induced Activity in Soils, AFSWP-518, June 1957, Secret – Restricted Data.





    It has a Foreword on page xxii by Edward N. Parker (Rear Admiral, USN), Chief, Armed Forces Special Weapons Project, stating:

    'The purpose of this manual is to provide the military Services with a compendium of the phenomena manifested by the detonation of nuclear weapons and the effects thereof in terms of damage to targets of military interest.

    'This edition of Capabilities of Atomic Weapons represents the continuing effort by the Armed Forces Special Weapons Project to make available the progressively improved data resulting from field testing, scaled tests, laboratory and theoretical analyses.


    '... Every effort has been made to include the best available data which will assist the using Services in meeting their particular operational requirements. As additional or better data becomes available it will be incorporated herein.'

    'In November 1964, DASA (Defence Atomic Support Agency) consolidated nuclear effects knowledge in the classified publication, Capabilities of Nuclear Weapons. A revised edition was published in 1968. These publications preceded the two-volume Effects Manual-1 (EM-1), first published in 1972. ... Integrating Knowledge: In 1972, DNA published a two-volume nuclear weapons effects manual called Effects Manual-1 (EM-1). Two years later, DNA issued a NATO-releasable [less classified] version of EM-1. These volumes provided critical planning information for unified and specified CINCs, civilian civil defense activities, and NATO officials.'


    - pages 16 and 19 of the colourful booklet, Defense Soecial Weapons Agency, 50th Anniversary 1947-1997. For a 466 page review published by the Defense Threat Reduction Agency in 2002, see AD-A412977 (35.3 Mb).

    All civil defence planning is either directly or indirectly (via Glasstone and Dolan Effects of Nuclear Weapons 1977) based on Dolan's Capabilities of Nuclear Weapons. The latest official American civil defence manual, for example, cites directly the secret 1988 revision of 'DNA EM-1 (Effects Manual 1), Capabilities of Nuclear Weapons, Chapter 10, July 1, 1972'; 'NATIONAL PLANNING SCENARIOS: Created for Use in National, Federal, State, and Local Homeland Security Preparedness Activities, Version 21.2 DRAFT, February 2006'.

    There is a definite need to debunk general Planet of the Apes style nuclear effects exaggeration hype by politicans which simultaneously:

    (1) encourages misguided nuclear proliferation (rogue states, dictators and terrorists think that simply having a nuclear threat will get them anything they want by intimidation, due to the exaggeration in the popular media) and

    (2) discourages simple civil defense countermeasures from being taken seriously. If you're in the crater region, you don't need civil defense, but as we've seen, even the crater sizes have been grossly exaggerated in the public domain. The "overkill" areas are trivial compared to the areas over which even the simplest informed civil defense countermeasures like duck and cover and getting out of the immediate downwind area (or under cover there) before the wind blows fallout there, is effective at saving lives.



    Why exaggerating the effects of aerial bombardment caused World War II

    The tragedy of the exaggeration of the offensive capabilities of aerial attack was plain to see during the 1930s. Public opinion was on British Prime Minister Neville Chamberlain's side (appeasing Hitler) because the effects of war had been exaggerated in 1938 by the British War Office: aerial bombing was (inaccurately) predicted to cause 121 casualties/ton, and the German air force was expected (for no reason other than doom mongering, it seems) to deliver its maximum capacity of 600 tons of chemical incendiary, gas and explosive bombs daily on Britain, killing 2.2 million people per month.

    Chamberlain and the British public were scared by these false "predictions" which were based on the WWI unopposed attacks in daylight and had no relevance for inaccurate nighttime bombing when enemy bombers were subject to AA and fighter defenses.

    In World War II a total of 71.27 kilotons (in average units of 175 kg of explosive, according to the British Home Office) of bombs, V1 cruise missiles and V2 supersonic ballistic missiles hit Britain, killing 60,595 and injuring 86,182, a casualty rate of 2 casualties/ton, 60 times fewer than the prediction based on World War I data!

    If Chamberlain and - more important - the general public had known the true civilian threat in 1938 from aerial attack instead of the hysterical exaggerations officially promoted, then Hitler might have been stopped or effectively deterred earlier on, with less cost in human lives. Exaggerating the effects of war and "discrediting" civil defense countermeasures using lying propaganda merely gave Germany years longer to prepare for war, which made the situation worse than it would otherwise have been if action had been taken before world war was inevitable.

    Dolan's 2-part secret revision was published in 1972 with 17 chapters which fitted into two loose-leaf binders, and a 22 chapter secret update under the editorship of Brode was published in 1991 (consisting of 22 separate volumes). In 1993, this final unwieldy revision was summarised as a set of the basic equations for predicting effects and issued in September 1996 as the 736 pages long Handbook of Nuclear Weapon Effects: Calculational Tools Abstracted from DSWA's Effects Manual One (EM-1) edited by John A. Northrop, and published by the Defense Special Weapons Agency.



    Above: John Northrop's 736 pages long Handbook of Nuclear Weapon Effects: Calculational Tools Abstracted from DSWA's Effects Manual One (EM-1) in September 1996 briefly summarized the formulas from the multi-thousand pages long 22-volume Capabilities of Nuclear Weapons, DNA-EM-1, while in July 2001 the 535 pages long first edition of Charles Bridgman's Introduction to the Physics of Nuclear Weapons Effects summarized the physics behind the formulae in Northrop's book.



    Capabilities of Nuclear Weapons, DNA-EM-1
    Philip J. Dolan (Editor), Stanford Research Institute
    July 1, 1972
    Change 1: July 1, 1978
    Change 2: August 1, 1981
    DEFENSE NUCLEAR AGENCY, WASHINGTON, D.C.

    Declassified on 13 February 1989.

    Part 1. Phenomenology.
    PDF download of Part 1, preliminary pages and contents pages, Change 2, August 1981 (45 pages, 1.6 MB) These pages are also available here.

    Chapter 1. Introduction. 30 pages.
    Chapter 2. Blast and Shock Phenomena. 306 pages. Blast wave section is here and ground shock/cratering/water bursts/underwater bursts section is here.
    Chapter 3. Thermal Radiation Phenomena. 114 pages.
    Chapter 4. X-Ray Radiation Phenomena. 30 pages.
    Chapter 5. Nuclear Radiation Phenomena. 151 pages.
    Chapter 6. Transient-Radiation Effects on Electronics (TREE) Phenomena. 16 pages.
    Chapter 7. Electromagnetic Pulse (EMP) Phenomena. 40 Pages.
    Chapter 8. Phenomena Affecting Electromagnetic Propagation. 94 pages.

    Part 2. Damage Criteria.
    PDF download of Part 2, preliminary pages and contents pages, Change 2, August 1981 (50 pages, 1.7 MB)

    Chapter 9. Introduction to Damage Criteria. 187 Pages.
    Chapter 10. Personnel Casualties. 38 Pages.
    Chapter 11. Damage to Structures. 50 Pages.
    Chapter 12. Mechanical Damage Distances for Surface Ships and Submarines Subjected to Nuclear Explosions. 147 Pages.
    Chapter 13. Damage to Aircraft. 81 Pages.
    Chapter 14. Damage to Military Field Equipment. 46 Pages.
    Chapter 15. Damage to Forest Stands. 64 Pages.
    Chapter 16. Damage to Missiles. 121 Pages.
    Chapter 17. Radio Frequency Signal Degradation Relevant to Communications and Radar Systems. 32 pages.
    Appendices A-F. 112 pages.



    Above: the island of Naan, located 18 miles from the 4.5 megaton Redwing-Navajo water surface burst was inundated by a wave 11 feet high which arrived swept over the island at 17 minutes after the detonation. (Source: 6 minutes into the declassified U. S. Department of Defense film linked here, Military Effects Studies on Operation Redwing, 1956.) There is some experimental data in chapter 2 of Dolan's manual on water waves from underwater and water surface burst tests. The actual depth of innundation is, however, not the water wave height over deep water, but greater because the wave height increases when it enters shallow water on the run up to the beach (underwater wave energy is conserved, so despite the drag effect of bottom sediment, more energy goes into the above-sea level water when the wave enters shallow water, until the wave breaks up into a surge-like a tsunami).

    TM 23-200 also gives a graph scaling the 25 kt British bomb-inside-ship-in-harbour shallow water underwater burst Hurricane fallout dose rate areas to a variety of yields (Hurricane fallout data had been given to America in 1954, in exchange for thermonuclear fallout data), which shows that for a fixed depth of water the fallout becomes more and more like a land surface burst as the yield increases into the megaton range, where the water layer thickness becomes negligible compared to the fireball size and you get a massive underwater crater (as occurred with the Redwing-Tewa shallow water 5.01 megatons burst over a reef at Bikini Atoll in 1956). TM 23-200 does not give any prediction system for dose rates from the passing base surge for underwater bursts, but does give empirical deposited fallout prediction systems for land surface and underground bursts based on scaling the 1951 Sugar and Uncle test fallout patterns using the fallout yield-distance scaling laws described in Glasstone 1957.

    Philip J. Dolan's 1972 DNA-EM-1 Capabilities of Nuclear Weapons by contrast gives a far more complete treatment of all the underwater burst problems. The final sections of Chapter 2 on blast and shock phenomena (over 300 pages) includes water shock, base surge, water waves from surface and underwater bursts, and so on, while chapter 5 on nuclear radiation phenomena gives computer predictions of base surge and water 'pool' dose rates and accumulated doses for yields of 1, 10 and 100 kt for various depths underwater and proximities of the bomb to the ocean bottom (the 1958 Umbrella test was detonated on the seabed, so there is evidence to validate such a preduction). The base surge part of that computer model was developed by I. O. Huebsch of the U.S. Naval Radiological Defense laboratory; see his 106 pages long May 1963 report USNRDL-TR-653, A Model for Computing Base-Surge Dose-Rate Histories for Underwater Nuclear Bursts (Confidential-Formerly Restricted Data):

    'A model for calculating transit-radiation dose rates and doses from the base surge of an underwater nuclear burst is described. Calculated values are compared with measurements made at Hardtack Wahoo and Umbrella, Crossroads Baker, and Wigwam, and with predicted values for two proposed underwater shots. The model is a geometrical-radiological representation of of the base surge, whose characteristics depend on weapon yield, burst depth and surface wind speed. The model is estimated to be valid for 1-kt to 100-kt underwater bursts for minimum depths of 20 to 90 ft, respectively, and for times at least 30 seconds after burst. Dose rates and doses can be computed for either fixed or moving points in the radiation field. The comparisons show that the calculated values, in almost all cases, agree within +/- 50% of the measured values. (Abstract UNCLASSIFIED.)'

    This base surge radiation model for underwater bursts was later supplemented with a code that predicts dosage from the expanding 'pool' of contaminated water (which is water that has been heated and contaminated with fission products by the pulsating bubble of the detonation as it rises, before erupting through the water). In nuclear tests, underwater radiation probes were able to distinguish this effect from the base surge radiation which was measured by probes above the water. The full computer code was finished in 1968 and is called 'Daedalus' (the 'cunning worker' of Greek mythology), the underwater equivalent of the land surface burst fallout computer code DELFIC:

    Edward A. Schuert, et al., DAEDALUS: A Gamma Exposure Rate Prediction Code for Underwater Nuclear Explosions, U.S. Naval Radiological Defense Laboratory, report USNRDL-TR-68-137, July 1968, Secret-Formerly Restricted Data.
    Above: example of an underwater burst base surge dose rate and expansion prediction given in Philip J. Dolan's originally secret manual Capabilities of Nuclear Weapons, DNA-EM-1, U.S. Department of Defense, Chapter 5, Nuclear Radiation Phenomena, August 1981 revision.Above: example of an underwater burst expanding water pool dose rate prediction given in Philip J. Dolan's originally secret manual Capabilities of Nuclear Weapons, DNA-EM-1, U.S. Department of Defense, Chapter 5, Nuclear Radiation Phenomena, August 1981 revision.

    A study of the hard-to-decontaminate soluble ionic fallout effects on adjacent land from a large underwater or water surface burst in San Francisco Harbor, based on nuclear test decontamination data, was presented to the U.S. Congressional Hearings on The Nature of Radioactive Fallout and Its Effects on Man in June 1957 (vol. 1, p. 318). The study assumed that 25 square miles would be decontaminated, consisting of all paved areas, all industrial and commercial areas and buildings, 50% of park areas, and 10% of the outlying residential areas (homes). Firehosing and earth moving were the methods considered, using nuclear test results.

    It was calculated that the decontamination would take 10,900 people altogether 28.5 days to complete, requiring 676,000,000 gallons of water, 341,000 gallons of gasoline and 195,000 gallons of diesel: 'The water requirements are within the capability of the normal supply. Fuel consumption is less than normal daily requirements. The greatest problem would undoubtedly be that of organizing, training, supervising, and controlling ...'

    Other relevant reports:

    Perkins, Peter R., Base Surge radioactivity from Underwater shots Wahoo and Umbrella, DASA 533, July 1960, originally Confidential.

    Swift, E., Jr., Liquid Model Studies of the Base Surge.

    OPERATION HARDTACK, PROJECT 2.3 - CHARACTERISTICS OF THE RADIOACTIVE CLOUD FROM UNDERWATER BURSTS ( 15 JANUARY 1962, EXTRACTED VERSION ) (DELETED)

    SHIPBOARD RADIATION FROM UNDERWATER BURSTS ( OPERATION HARDTACK-I ) PROJECT-2.1
    DISTRIBUTION OF RADIOACTIVITY IN SEA WATER AND MARINE ORGANISMS FOLLOWING AN UNDERWATER NUCLEAR DETONATION AT THE ENEWETAK TEST SITE IN 1958.
    FALLOUT IN THE OCEAN ( STATEMENT PREPARED FOR THE SPECIAL SUBCOMMITTEE ON RADIATION, JCAE, CONGRESS OF THE U.S. FOR PUBLIC HEARINGS ON FALLOUT FROM NUCLEAR WEAPONS TESTS, MAY 5-8, 1959 )
    OPERATION REDWING, PROJECT 2.62A, FALLOUT STUDIES BY OCEANOGRAPHIC METHODS PACIFIC PROVING GROUNDS, MAY - JULY 1956 (DELETED)
    FALLOUT LOCATION AND DELINEATION BY AERIAL SURVEYS (U) ( OPERATION REDWING - ( PROJECT 2.64 ) ( NYO PROGRAM ) (DELETED)
    COMPILATION OF LOCAL FALLOUT DATA FROM TEST DETONATIONS 1945-1962 EXTRACTED FROM DASA-1251 VOLUME-II OCEANIC U.S. TESTS (DELETED)
    PROOF TESTING OF ATOMIC WEAPONS SHIP COUNTERMEASURES - CASTLE OPERATION, PROJECT 6.4

    Merritt, M L, Air Pressures from a Deep Underwater Burst, Wigwam Project 4.5, WT-1035, originally Secret-Restricted Data, 1955.

    ‘When a constrained column of dense liquid standing on the bottom of a tank of water is released suddenly, it sinks and flows outward radially along the bottom. This action simulates the early motion of the base surge from shallow underwater explosions. Such liquid model experiments are described, scaling laws are derived, and comparisons with Crossroads-Baker are made. It is estimated that between 100,000 and 130,000 tons of water in the Baker column contributed to the surge, that the column height was between 3,500 and 4,000 feet [1.1-1.2 km], and that the column density was between 1.4 and 1.6 times that of air.’ – E. Swift, Jr., Liquid Model Studies of the Base Surge, U.S. Naval Ordnance Laboratory report NOL-TR-62-191 (1962).

    According to pages 102-3 of "The Effects of Atomic Weapons" (1950), the Baker test caused an irregular crater in the mud or sediment of the lagoon bottom which was up to 10 m deep and about 800 m in diameter. A total of about 2.8 million cubic metres of material was displaced, of which 61 % settled back in the crater, partially refilling it: "This 'target area mud' had a median diameter of 7.5 microns; 75 percent of the material was less than 20 microns and 25 percent less than 2.5 microns in diameter." The total volume of material permanently removed from the cratered region (i.e., the volume carried into the Baker mushroom cloud) was 1.1 million cubic metres (about 2 million metric tons of mud).



    Above: a slow-speed replay of the film. Notice the very brief fireball flash (negligible thermal radiation was radiated because the vaporization of water cooled the fireball/bubble to a relatively low temperature before it erupted through the water surface), and the development of the base surge at the foot of the column as the latter collapses.

    If the detonation is as deep as the Baker test, the water absorbs the flash of initial nuclear radiation, preventing EMP. The bulk subsidence of the water spray droplet column in air is similar to the flow of coloured dense (salty) water when poured into fresh water. Dr William G. Penney vividly described the Baker test base surge in a BBC broadcast as: ‘a thin pancake mixture spreading as it is poured into a frying pan.’ The average 10-micron diameter droplets in the base surge take 562 seconds (9.4 minutes) to evaporate in 100% humidity, 20 °C warm air. In air of over 68% humidity, water evaporating from small droplets condenses on to the larger droplets, forming raindrops, with a base surge ‘rainout’, as in the Baker test (73% humidity). In dry air, water evaporates, leaving only very small salt crystals.

    In chemical explosions underwater, the temperature falls to below 100 °C before the bubble erupts into the air, so there is no superheated salty steam column (needed to create the small droplets for a base surge). So most of the water droplets thrown up mechanically in chemical underwater explosions are large, and they simply fall straight back into the sea instead of flowing over the surface with air in a fluid, foggy base surge. However, there are some small water droplets formed which do create a base surge, as seen in the film of an underwater depth charge explosion linked here.

    Volcanoes can also cause lethal base surges. The 1965 eruption of the Taal volcano in the Philippines caused a base surge that travelled 4 km, killing 189 people. In 1980, the eruption of Mount St Helens was instrumented, and a base surge cloud of choking hot ash mixed in air at 465 °C was filmed to roll outwards at a speed of 160 km/hour. A base surge in 79 A.D. was described as a dark cloud by the Roman eye-witness Pliny the Younger, and this killed 20,000 people in Pompeii, during the eruption of Mount Vesuvius. People cannot outrun the fast-moving close-in base surge.

    At 640 m from Baker, a lethal human gamma dose on ship decks was recorded within just 30 seconds of detonation; at 1,550 m it was received in 7 minutes, while 2,300 m downwind it took 3 hours to accumulate (due to contamination from rainout on deck). About 88% of the maximum deposited activity from Baker was due to mushroom cloud rainout and 12% was deposited by the base surge. The total deck dose to 1 hour after burst due to deposited activity ranged from 140 R for the LCI-332 (1.83 km east of the detonation) to 3850 R on the Pensacola at 457-m south-west of the detonation). Below deck, these doses were reduced by factors of 4-40, depending on location. When sailing through contaminated waters after burst, the dose rate on deck was only 50% of the dose rate at the water surface. People can shelter below deck in ships or indoors on land, closing hatches and windows. Although the Baker test only sank 8 ships and seriously damaged 8 others from shock (6 of which were later deliberately sunk in Bikini Lagoon because they were irreparable), a further 42 ships were sunk because fission products (present as charged metal ions) became chemically attached to the rusting steel.

    Decontamination was attempted by 2,000 sailors, trying to scrub and scrape decks in the humid Pacific heat without any protective clothing, but this proved of limited value against hard rust and was cancelled on 10 August 1946, due to worries about plutonium dust. The expense of sand blasting the ships clean exceeded their value to the U.S. Navy, although 22 contaminated ships were towed to San Francisco for study, and were afterwards sunk.
    Above: Baker fallout contamination levels, based on records for containers which retained the liquid fallout (not deck readings, because the rain ran off the decks reducing the contamination on them by a large factor; see the patterns below for BAKER in pages from 'The Effects of Atomic Weapons: 1950' for the deck radiation dose rate readings, which were much lower because most of the contamination ran straight back drains and then into the sea where it was diluted and shielded by the water to give gamma dose rates hundreds of times lower than you get above contamination on land). According to Capabilities of Atomic Weapons, TM 23-200, Confidential, November 1957 (with 3 October 1960 "change 2" page updates), page 4-32, the Baker results indicated that dose rates on ship decks after contamination occurred were only a quarter of those on adjacent land due to the ocean water which shielded the radiation from the fallout which landed in the surrounding area:

    "It was shown that for a ship subjected to fallout radiation, much of the contaminated fallout material drains off the ship into the water, and rapidly becomes relatively ineffective because of dilution due to mixing in water. For adjacent land areas, residual radiation dose rates are about four times as great as on board ship at the same relative position are expected soon after completion of fallout, because dilution and run off do not occur." [Emphasis added.]

    This statement is confused in the sense that even if there is no escape of water from decks back into the sea, the radiation level on the ship deck will still be shielded due simply to the removal of the surrounding contamination due to its sinking into the sea. On a flat surface only 50% of the dose rate at 1 metre height comes from within a 15 metres radius. On a ship, even if all the fallout that lands on the deck remains there, the dose rate on the deck is lower than on land because you don't have contributions from beyond the deck. The reduction comes from the sinking of the fallout into the sea around the ship, which on land would be unshielded and would contribute to the dose rate. The factor of 4 protection agrees with data in report WT-1317 for Operation Redwing where unprotected barges and ships had radiation meters and fallout collectors, and there was no drainage due to solid fallout deposition from land surface bursts Tewa and Zuni. The ships and barges gave deck radiation exposure rate data which for similar times and scaled to similar masses of fallout activity deposited were only a quarter of those recorded by radiation meters on the islands well away from the sea.

    Here is a film of the 1952, 25 kt British 1952 Hurricane nuclear test detonated 2.7 m below the waterline inside a ship located in 12 m deep (i.e. shallow) water, showing the fissile core insertion into bomb, followed by colour film of slow motion fireball expansion, crater mud and water throwout, and cloud formation:



    Above: the fallout pattern version given to me for the British Hurricane 25 kt very shallow underwater test which was exploded 2.7 m below the waterline inside the hull of HMS Plym a 1,370-ton River class frigate anchored in 12 m of water, 350 m offshore, creating a saucer-shaped crater on the seabed 6 m deep and 300 m across (kindly supplied by Aldermaston in 1995 after it was declassified, compared to the American version in report ADA956123, which unfortunately does not contain the best data). The unclassified version of the Hurricane test film (black and white only) is available on the National Archives website:

    http://www.nationalarchives.gov.uk/films/scripts/newwmv.asp?clip_name=Operation-Hurricane-512K.wmv&title=Operation%20Hurricane&clipSpeed=512k

    Above: comparison of base surge gamma radiation dose rates and total accumulated doses from 1958 Hardtack underwater shots Wahoo (9 kt, 152 m depth of burst in deep water) and Umbrella (8 kt, 46 m depth of burst on the lagoon bottom).

    Above: Wahoo pattern of total gamma dose to 6 hours after burst.

    Above: Umbrella pattern of total gamma dose to 6 hours after burst.

    Above: 1958 Hardtack underwater shots Wahoo and Umbrella (see also the film of the Wahoo base surge engulfing a ship linked here, the Wahoo test in black and white from another camera linked here, and the film of Umbrella linked here).


    Above: Wigwam very deep underwater burst in 1955 (32 kt at 610 m depth in water nearly 5 km deep) gamma dose rate in water at 1.4 hours after detonation. Because of the depth of the explosion, the bubble mixed with the water and largely disintegrated into foam before venting, so that relatively little radioactivity reached the surface.

    Above: the 1955 Wigwam deep underwater test (32 kt at 610 m depth in water nearly 5 km deep).
    Above: the decaying gamma radiation at 24 hour intervals from the drifting water pool of the last ever underwater nuclear test, the ASROC system proof test, a deep burst fairly similar to Wahoo called Swordfish, 1962 (18 kt detonated at 206 m depth in 5,220 m deep ocean) as measured by aircraft flying at 500 ft altitude. (Reference: E. J. Wesley, et al., Aerial survey of the surface radioactivity remaining after an underwater nuclear detonation, USNRDL-TR-626, March 1963, Secret.)



    Above: The first nuclear explosion at Novaya Zemlya was a 3.5 kt nuclear warhead RDS-9 for Torpedo T-5 at a depth of 9.8 metres (32 feet) underwater on 21 September 1955. Some 30 ships including 4 destroyers and 3 submarines containing 500 goats and sheep and 100 dogs were located at distances of 300-1,600 m; only the destroyer at 300 m sank immediately from water shock wave damage. (V. A. Logachev, et al., Novaya Zemlya Test Site. Ensuring the General and Radiological Safety of the Nuclear tests: Facts, Testimonies, Memories, IzdAT, Moscow, 2000, 485 pp.) This was a scaled-down version of the American 1946 Baker test. Early American information released about Baker falsely indicated that it was detonated at 50 feet depth in 200 feet of water, whereas it was actually detonated at 90 feet depth in 180 feet depth of water; it is interesting that this deception slightly confused the precise choice of the scaled depth to be used in this Russian underwater test: they simply scaled down from the supposed 50 feet depth of burst for supposedly 20 kiloton Baker to get 32 feet for 3.5 kilotons using the 1/4-power scaling law, i.e., 50*(3.5/20)1/4 = 32 feet. This Russian test was also interesting because of the low humidity of the cold arctic air at Novaya Zemlya, within the arctic circle, compared to the high humidity (73%) in the Baker test at Bikini Atoll. It is significant that the base surge, column and cauliflower cloud are exactly as occurred in the Baker test, although unlike Baker there is no Wilson condensation cloud around the column, due to the low humidity at Novaya Zemyla.



    Above: all three Russian underwater nuclear tests were detonated in the same location: 70.703 degrees North, 54.60 degrees East, Guba Chernaya Bay, Novaya Zemyla. (That bay has relatively shallow water, like Bikini or Eniwetok Lagoon.)





    Above: on 10 October 1957, a 9 kt T-5 nuclear torpedo detonated at a depth of 29.3 m (96 feet) in the same location as the previous Russian underwater test at Novaya Zemlya. A submarine launched the torpedo. Three destroyers, three submarines, two minesweepers, and smaller target ships, were sunk by the shock. (V. A. Logachev, et al., 'Novaya Zemlya Test Site. Ensuring the General and Radiological Safety of the Nuclear tests. Facts, Testimonies, Memories', IzdAT, Moscow, 2000, 485 pp.) This second Russian underwater test was very similar to the American Umbrella test, producing a tall column with no mushroom top or cauliflower cloud atop the stem or column. The reason for the difference in cloud shape is the bubble pressure when it vents at the air-water surface. The bubble from a 1 kt burst detonated at a depth in excess of 23 metres will only reach the surface after the pressure in the bubble has fallen below ambient air pressure, hence there is 'blow in' of air to the cavity. This occurs because the greater depth gives steam the chance to condense into water, reducing the steam pressure in the bubble. Hence, there is no 'blow out' of steam in such a detonation, and no cauliflower shaped top to the cloud, merely a column of water. Underwater bursts of 1 kt at depths shallower than 23 metres cause the bubble to reach the surface sooner and erupt while there is still some steam pressure remaining, so you get a 'blow out' of the bubble steam, which quickly condenses in the unconfined air to form the cauliflower-shaped top of the mushroom cloud above the water spray column. This Russian test was detonated at a scaled depth near the borderline between bubble 'blowout' (bubble steam above ambient air pressure when venting) and bubble 'blowin' (bubble steam below ambient air pressure when venting), so it was probably near ambient air pressure when venting. It is therefore really in the transition zone between the blowout of Baker shallow bursts and the blowin of Umbrella (slightly deeper) bursts. (The third and final Russian underwater test, at exactly the same location as the two previous Russian underwater tests, was 4.8 kt at 19.5 metres (64 feet) depth on 23 October 1961, and was the system proof test of a nuclear torpedo launched from a B-130 submarine. Altogether, there have been a total of nine underwater nuclear weapon tests: the three Russian shots, the five American shots Baker, Wigwam, Wahoo, Umbrella, and Swordfish, and the British very shallow underwater test in very shallow water, Operation Hurricane, which gave information on the transition zone between a land surface burst and an underwater burst.)

    According to the Russian report by V. A. Logachev, et al., Novaya Zemlya Test Site. Ensuring the General and Radiological Safety of the Nuclear tests: Facts, Testimonies, Memories (IzdAT, Moscow, 2000, 485 pp.), all the tests at Novaya Zemlya were free air bursts or underground tests, apart from the three underwater tests, one low altitude tower shot (the second nuclear explosion at Novaya Zemlya was a 32 kt near surface burst on top of a 15 metres high tower on 7 September 1957, some 100 meters inland from the coast at Guba Chernaya Bay, producing a crater 80 m in diameter and 15 m deep; at one hour after burst the gamma exposure rate at ground zero was 40,000 roentgen per hour, if the Russian extrapolation back to 1 hour is accurate), and two water contact surface bursts. On 27 October 1961, the same B-130 submarine, at a distance of 11 km, launched a 16 kt torpedo which traveled 11 km underwater at a depth of 12 m, then detonated 1.1 metres above the water. Adjacent land was contaminated with fallout. On 22 August 1962, a 6 kt contact surface water burst of an antiship nuclear warhead rocket occurred, launched from a Tu-16 aircraft. The water surface bursts reportedly caused more residual contamination on land than the underwater bursts, although that might have partly just a consequence of the wind direction.

    According to "The Effects of Atomic Weapons" (1950), pp. 104-5:

    'The suspension of water drops behaved at first like a homogeneous fluid of somewhat higher density than the air outside the column. Exactly similar phenomena have been observed in laboratory studies of the rate of aerosols and liquid suspensions conducted at Stanford University under the direction of P. A. Leighton. In these experiments, drops of an aerosol or of a liquid suspension were introduced at the top of a glass cylinder into a fluid of very slightly lower density. The aerosol drops settled at rates up to 10,000 times greater than the velocities of fall of the individual suspended particles they contained, as computed from Stoke's law. This phenomenon was called 'bulk subsidence'. It is an example of the more general class of flow which has been designated as a density current, that is, the flow of a fluid under the action of gravity through another fluid of slightly different density.

    'After 10 to 12 seconds, the suspension of water and air over the entire periphery of the column constituting the plume began to fall rapidly. ...the plume was an essentially hollow cylinder with walls approximately 300 feet thick. This conclusion is supported by the 'hollow' appearance of the cauliflower cloud, as seen from above in some of the aerial photographs.

    'As the falling suspension of water in air from the outer part of the column reached the sea surface, it billowed outward and upward as the 'base surge'. This was first evident between 10 and 12 seconds after the burst. At first the front of the base surge moved outward in all directions with a very high velocity, in exces of 100 feet per second, but this velocity rapidly diminished. ...

    'At 12 seconds, the suspended material in the cauliflower cloud began to fall back into the lagoon in large mamillary masses, which attained high settling velocities of more than 50 feet per second. In some cases an abrupt decrease of velocity occurred after an interval, and the plume broke up into a rain curtain. Evidently the same mass subsidence phenomena occurred in the cloud as in the column. The first material from the cloud reached the surface about 1 minute after the detonation, and after 2.5 minutes the cauliflower cloud had dropped nearly all its suspended load into the base surge so that only the remnants of it remained aloft. Most of this material fell in an annular area with inner and outer radii of 1,950 and 2,850 feet, respectively. The aerial photographs show part of the lagoon surface inside this annular area after 45 seconds, indicating that at this time there was little suspended material either from the cauliflower cloud or the base surge in the central region. beyond the annular ring of fall-out from the cloud, the base surge extended over a very large area, with an average outer radius at 3.5 minutes of 8,400 feet.

    'For the first 2.5 minutes, the height of the top of the base surge increased irregularly but continuously up to about 1,800 feet."

    Above: the base surge average radius (crosswind; in the upwind and downwind directions it was obviously displaced by the wind), velocity and height as published in the 1950 book "The Effects of Atomic Weapons", page 107. This was removed from subsequent editions. (Click on image for larger view; this also applies to most other images on this blog since the software doesn't display them in full resolution on the main page.)



    Above: another page from the 1950 "Effects of Atomic Weapons", showing the total accumulated dose from the Crossroads-Baker base surge as it passes different locations. This vital information was also removed from subsequent editions. Further pages from the same book follow, showing deposited (rainout/fallout) contamination dosage, total dosage, and dose rates on ships where most of the contamination ran off the deck back into the sea (the text says that this would apply on land for city areas with good drainage, since most of the radioactive rainout/fallout would run down the drains where the gamma radiation would be very well shielded from the street above).











    In regard to the Crossroads-Baker test, it is worth mentioning the various other effects, ap[art from the radiation hazards mentioned already. Surface water waves were caused by the bubble expansion and venting phenomena such as the refilling with water of the bubble volume. The number of water waves increased with distance, according to "The Effects of Atomic Weapons", from 3 at 640 m to 6 at 3 km and 14 at 6.7 km. Within 2.4 km of the detonation, the first of these waves was the highest and has a height from crest to trough of 8730/R metres, where R is distance in metres from detonation. Beyond 2.4 km, the highest water wave was not the first one but was further back in the wave train, and the maximum height was 15 % greater than given by the formula for the first wave height. The first wave velocity was (gd + gh)1/2 where g is acceleration due to gravity (9.81 m/s2) d is the depth of the water, and h is the wave height. This speed was 23 m/s for very long distances (small wave heights) in Bikini Lagoon, but considerably faster near the explosion. As the waves approached Bikini Island beach, 5.64 km from the Baker burst, they entered shallower water which caused them to (a) slow down and (b) increase in height as energy was transformed from horizontal propagation to vertical displacement. The waves approached Bikini Island beach 5.1 minutes after burst with a height of 2.1 metres. The first wave peaked up and broke up when its slope from trough to crest exceeded 15 degrees, some 120 metres off the Bikini Island beach, in water 6 metres deep. When peaking this wave attained a height of 4.6 metres, over twice the height in deep water at the same distance from the burst. The height of the wave when breaking in shallow water of depth d is always bigger than that in deep water of depth D by the factor 1.3(D/d)1/4. The Baker test radiated 0.35 % of its energy as water surface waves, with over half the energy in the first wave.
    Data on the peak water overpressure, peak air overpressure, and the explosion yield scaling for all these efects and for the surface water wave heights were first published in the 1957 edition of "The Effects of Nuclear Weapons", pp. 221-5 (the 1950 book only gave detailed data on the radiation and surface - i.e., transverse - water waves from Baker, not on the longitudinal shock waves in water and air which remained secret at that time). The maximum crest-to-trough height of the first wave from Baker test was 8730/R metres, for distance R in metres, as given by data in the "The Effects of Atomic Weapons" 1950, but the 1957 edition gave the scaling law to extrapolate the Baker data to other yields: for a bomb of yield W kilotons in water 26W1/4 metres deep, the maximum crest-to-trough wave height is 1950W1/2/R metres, where again R is distance in metres. (The data in the 1962/4 editions of "The Effects of Nuclear Weapons" disclosed the additional nuclear testing fact that, for bursts in water more than 120W1/4 metres deep, the maximum crest-to-trough wave heights are bigger by a factor of 2.4 than in the case of the shallow water Baker test conditions.)

    The peak water overpressure for Baker was 60,000,000/R1.63 psi at distance R metres (units conversion factor: 1 psi = 6.9 kPa). This gave the 1957 "Effects of Nuclear Weapons" scaling law for peak water overpressure for a burst at mid-depth in water 20W1/3 metres deep: P = 12,000,000W0.54/R1.63 psi. Peak water overpressures of 3000-4000 psi sank ships by bursting open the seams of steel plates, while 1000-2000 psi caused serious damage to propulsion units and some flooding. Lower pressures only tended to cause displacement effects to equipment inside the ship.

    The peak air overpressure from Baker was 4,400/R psi, equivalent to 1610W1/3/R psi for a burst at mid-depth in water 20W1/3 metres deep.



    Above: despite the candour in "The Effects of Atomic Weapons" 1950 with regard to the Crossroads-Baker underwater burst radiation patterns, the book was misleading about the first near-surface burst effects (the Trinity test contamination pattern, New Mexico, 16 July 1945, 19 kt at 30 metres altitude), presenting the upwind fallout contamination and a small amount of neutron induced activity (the radioactivity was mainly fission product activity in glassy slag on the crater floor which was created by contact of the hot fireball on the sand) radii as if the fallout pattern was just a small circle around ground zero. The text later on the same page (page 270 of "The Effects of Atomic Weapons", 1950) vaguely states:

    "The disturbance of earth and other material in the formation of a crater, which accompanies an air burst at low altitude, results in the deposition of contaminated debris at some distance away. In addition, much of the dust is carried aloft into the atomic cloud, but it eventually settles to the earth as the fall-out, after picking up fission product particles, to contaminate areas much further from the centre of the explosion. After the Almogordo test, for example, high concentrations of radioactivity were detected on the ground several miles north and east of the site of the explosion. The integrated dose was, however, not dangerous to human life.*"

    The small-print footnote (*) on page 271 states that hair loss and blisters occurred on the 75 cattle located 10-15 miles downwind from the Trinity test: "In the course of a few weeks, loss of hair and blisterlike lesions were apparent. The latter soon healed, however, and the hair, originally red in color, grew again, although it was white or grey in color. Continued observation of the animals has shown that the cows have produced normal calves, irrespective of whether they were mated with bulls which had or had not been exposed to the radioactive dust. There was, by the end of 1949, no evidence of the radiation, other than the graying of the hair."

    It is pretty obvious that the Trinity fallout (pattern below) was being understated by Glasstone in 1950. The beta radiation burns to the thick hides of cattle at 10-15 miles downwind from Trinity, a low air burst, were a clear warning of human risks and obviously suggestive of far more serious beta burns, that would have occurred to unprotected human beings at such distances from such a low yield tower burst detonation (or much further downwind from a megaton range surface burst). If the information had been presented more clearly in 1950, the serious contamination and beta burns to the Marshallese on Rongelap Atoll 115 miles downwind from the 14.8 megatons Castle-bravo nuclear test of 1 March 1954 could have been averted. Since Castle-Bravo was a surface burst with an energy yield 780 times larger than Trinity, it should have been obvious from any scaling system than Rongelap was at risk once the wind pattern was known and it should not have taken two days to evacuate the Marshallese. The cover up of the Trinity fallout pattern for obscure reasons of secrecy put human lives in danger.


    Above: This is the fallout pattern from the first ever nuclear test, Trinity, 16 July 1945. One of the gross errors in Glasstone's 1950 Effects of Atomic Weapons was a total omission of this fallout pattern, compounded by a statement of the 'trinitite' (glassy fused sand) crater residual radiation levels near and upwind of ground zero. Glasstone's 1950 book records that at ground zero the dose rate at 1 hour was 8,000 R/hr of gamma, and gives upwind radii for other dose rates, but omits the downwind fallout pattern. This probably contributed to speculation of a cover-up when Marshallese received beta burns from fallout in 1954. The Trinity test was about 19 kilotons on a 30 metres high tower. The effective (altitude averaged) wind speed for the fallout was 27 km/hour. The gamma dose rate contour values on the pattern above are scaled back to 1 hour after burst using the t-1.2 decay rate law (which was discovered from the Trinity fallout analysis), a time before actually fallout arrived in many of the locations shown, from measurements taken after fallout was complete. The contour values from ground zero outward are consecutively labelled: 75, 10, 5, 2, 0.5, 0.1, 0.05, and 0.01 R/hour. Just to emphasise: these dose rates didn't actually occur at 1 hour except within 10 miles of ground zero. (The habit of referring all fallout dose rates to a time of 1-hour after detonation creates a lot of confusion when people look at such patterns.) Source: DASA-1251-1-EX (secret 1963 report, finally declassified and released in 1979).
    Another report containing some extracts from secret integrations of the dose rate activity patterns in that report is this one (Jack C. Greene, et al., U.S. Department of Defense "Response to DCPA Questions on Fallout", DCPA Research Report No. 20, Nov. 1973), Table 1 of which shows that the total local fallout from Trinity was a sizable fraction of what is deposited in a true surface burst, and remarks on page 8:

    "The most critical point for establishing the dependence of [the fallout dose rate normalization] K-factor on building height appears to be the Trinity shot, analogous to one megaton on a 30-story building."

    Clearly, therefore, Trinity fallout data is taken seriously and it is possible to scale it to represent the fallout from a megaton bomb hitting a city skyscraper. It shouldn't have been covered up in 1950.

    Above: the 1957 edition of Glasstone's "Effects of Nuclear Weapons" shows the hair loss and beta burns to the Marshallese. If the hair loss and beta burns to the cattle 10-15 miles downwind from 19 kt Trinity in July 1945 hadn't been relegated to a footnote in small print in the 1950 edition, but had instead been presented as a warning of the dangers to human beings and been accompanied by the downwind fallout pattern from Trinity, then the 14.8 megaton Bravo surface burst test in 1954 with Marshallese 115 miles downwind, would have been conducted more carefully. The fallout took 4 hours to reach them, and they could have been evacuated a lot sooner - avoiding injury - if the right people had been aware of the solid information already available on fallout.
    However, it is clear that "The Effects of Atomic Weapons" (1950) was a step in the right direction, and was trying to mitigate the anti-radiation hysteria in the media at that time, as is clear from its discussion of radiological warfare on page 289:
    "Perhaps the most important application of radiological warfare would be its psychological effect as a mystery weapon, analogous to the initial use of poison gas and of tanks in World War I. The obvious method to combat radiological warfare in this case is to understand and be prepared for it."
    This is spot-on. However, the way to understand and be prepared for radiological warfare is to know the full facts, without any prejudice. One more useful thing pointed out in "The Effects of Atomic Weapons", page 288, is:
    "... the formation of radioisotopes in a nuclear reactor, as a result of neutron capture, means that an equivalent amount of fissionable material, which can be used in a bomb, will be sacrificed [because you need 1 neutron to induce activity in 1 atom, and that neutron could instead have been better employed by being captured by U-238 to form U-239 which decays into Np-239 and then Pu-239, which can be used as a fissile material in nuclear weapons]."
    On the subject of decontamination of the Baker test fallout contamination from ships, it states on page 313:
    "At Bikini the U.S.S. Independence, a small aircraft carrier, received such a large radiation dosage that had there been any personnel on the hangar deck at the time they would have succumbed from external radiation, apart from the efects of blast. Yet 2 weeks after the detonation the dosage rate was about 3 r per day, permitting short time access. About a year later, the average dosage rate was only 0.3 r per day, and 3 years after the original contamination the Independence was in use at the San Francisco Naval Shipyard, where it housed the experimental engineering group of the Naval Radiological Defense Laboratory. It was difficult at that time to find any areas on the ship where the radiation dosage would have exceeded the limit of 0.3 r per week adopted in installations of the Atomic Energy Commission.
    "It should be noted that no decontamination of the Independence was attempted, primarily because the vessel was in a battered condition, and it seemed unlikely that she could be returned to service as an aircraft carrier. However, some of the other vesels at Bikini were decontaminated and reclaimed much sooner."
    Updates:
    The U.S. Department of Energy has now transferred all the PDF format declassified Marshall Islands nuclear test reports to the new online database at: https://hss.doe.gov/HealthSafety/IHS/marshall/collection/
    For example, the 1957 edition of "The Effects of Nuclear Weapons" is located at: http://www.hss.energy.gov/healthsafety/ihs/marshall/collection/data/ihp1d/15143e.pdf
    Also on that site are vital reports on underwater nuclear test burst effects, including:
    U.S. Defense Nuclear Agency's "HANDBOOK OF UNDERWATER NUCLEAR EXPLOSIONS" ( U ) VOLUME 2 - PART 2, March 1972, report DNA 1240H-2, http://www.hss.energy.gov/healthsafety/ihs/marshall/collection/data/ihp1c/0439_a.pdf
    OPERATION HARDTACK PROJECT 2.1, SHIPBOARD RADIATION FROM UNDERWATER BURSTS (DELETED)
    OPERATION HARDTACK, PROJECT 2.3 - CHARACTERISTICS OF THE RADIOACTIVE CLOUD FROM UNDERWATER BURSTS ( 15 JANUARY 1962, EXTRACTED VERSION ) (DELETED)
    PROOF TESTING OF ATOMIC WEAPONS SHIP COUNTERMEASURES - CASTLE OPERATION, PROJECT 6.4
    INITIAL GAMMA DATA FROM NUCLEAR WEAPON TESTS 1948 THROUGH 1962 (DELETED)
    COMPILATION OF LOCAL FALLOUT DATA FROM TEST DETONATIONS 1945-1962 EXTRACTED FROM DASA-1251 VOLUME-II OCEANIC U.S. TESTS (DELETED)
    REVISED DRAFT OPERATION REDWING PROJECT 2.2 GAMMA EXPOSURE RATE VERSUS TIME ( U ) (DELETED)
    PRELIMINARY REPORT OPERATION REDWING PACIFIC PROVING GROUNDS MAY - JULY 1956 PROJECT 2.66 EARLY CLOUD PENETRATIONS

    OPERATION CASTLE - PROJECT 2.7, DISTRIBUTION OF RADIOACTIVE FALLOUTBY SURVEY AND ANALYSES OF SEA WATER (DELETED)

    OPERATION CASTLE SUMMARY REPORT OF THE COMMANDER, TASK UNIT 13 - MILITARY EFFECTS, PROGRAMS 1-9 (DELETED)
    OPERATION CASTLE - PROJECT 2.6A, CHEMICAL, PHYSICAL, AND RADIOCHEMICAL CHARACTERISTICS OF THE CONTAMINANT (DELETED)
    OPERATION IVY, PROJECT 5.4B, FALLOUT AND CLOUD-PARTICLE STUDIES ( NOVEMBER 1952 )
    OPERATION CASTLE, PROJECT 2.5A, DISTRIBUTION AND INTENSITY OF FALLOUT, REPORT TO THE SCIENTIFIC DIRECTOR

    OPERATION REDWING, PROJECT 2.62A, FALLOUT STUDIES BY OCEANOGRAPHIC METHODS PACIFIC PROVING GROUNDS, MAY - JULY 1956 (DELETED)

    OPERATION UPSHOT-KNOTHOLE, BLAST EFFECTS ON B-36 TYPE AIRCRAFT IN FLIGHT, PROJECT 5.3 ( MARCH - JUNE 1953 )
    PROOF TESTING OF ATOMIC WEAPONS SHIP COUNTERMEASURES - CASTLE OPERATION, PROJECT 6.4
    REVIEW OF MEDICAL FINDINGS IN A MARSHALLESE POPULATION TWENTY-SIX YEARS AFTER ACCIDENTAL EXPOSURE TO RADIOACTIVE FALLOUT
    RADIATION HAZARDS DURING ATOMIC WARFARE (U) (DELETED)
    OPERATION CASTLE, PROJECT 6.5, DECONTAMINATION AND PROTECTION

    RADIOACTIVE FALL-OUT FROM ATOMIC BOMBS (DELETED)

    REPORT TO THE SCIENTIFIC DIRECTOR - NATURE, INTENSITY, AND DISTRIBUTION OF FALL-OUT FROM MIKE SHOT, PROJECT 5.4A, NOVEMBER 1952 ( IVY OPERATION )
    OPERATION HARDTACK PROJECTS 2.9/2.12B GAMMA DOSE FROM VERY-LOW-YIELD BURSTS APRIL - OCTOBER 1958 (DELETED)
    RESPONSE TO DCPA QUESTIONS ON FALLOUT ( DCPA RESEARCH REPORT NO. 20 )

    OPERATION CASTLE - PROJECT 2.5B, FALLOUT STUDIES (DELETED)

    OPERATION TEAPOT, PROJ 37.3, EVALUATION OF THE ACUTE INHALATION HAZARD FR RADIOACTIVE FALL-OUT MATERIALS BY ANALYSIS OF RESULTS FR FIELD OPERATION + CONTROLLED INHALATION STUDIES IN THE LABORATORY

    OPERATION CASTLE - PROJECT 2.6A, CHEMICAL, PHYSICAL, AND RADIOCHEMICAL CHARACTERISTICS OF THE CONTAMINANT (DELETED)

    OPERATION CASTLE, PROJECT 2.5A, DISTRIBUTION AND INTENSITY OF FALLOUT, REPORT TO THE SCIENTIFIC DIRECTOR

    OPERATION HARDTACK PROJECT 2.8, FALLOUT MEASUREMENTS BY AIRCRAFT AND ROCKET SAMPLING (DELETED)

    OPERATION HARDTACK, PROJECT 2.8 - AIRCRAFT AND ROCKET FALLOUT (DELETED)

    OPERATION REDWING - PROJECT 2.1, GAMMA EXPOSURE VERSUS DISTANCE (DELETED)
    OPERATION CASTLE - PROJECT 9.1, CLOUD PHOTOGRAPHY
    OPERATION REDWING, PROJECT 2.66B, CONTACT RADIATION HAZARD ASSOCIATED WITH AIRCRAFT CONTAMINATION BY EARLY CLOUD PENETRATIONS

    OPERATION REDWING - PROJECT 2.63, CHARACTERIZATION OF FALLOUT, PACIFIC PROVING GROUNDS, MAY - JULY 1956 (DELETED VERSION)

    PROCEEDINGS OF THE SECOND INTERDISCIPLINARY CONFERENCE ON SELECTED EFFECTS OF A GERAL WAR ( 2ND ) VOLUME II
    THE TURQUOISE BOOK, OPERATION IVY (DELETED)
    EVALUATION OF RADIOACTIVE FALLOUT ( EXTRACTED VERSION )
    GAMMA DOSE RATES AT RONGELAP ATOLL 1954-1963 ( BRAVO EVENT, CASTLE OPERATION FALLOUT ON RONGELAP TIME STUDY )
    WORLD-WIDE FALLOUT FROM OPERATION CASTLE (DELETED)
    THE NATURE OF INDIVIDUAL RADIOACTIVE PARTICLES, VI. FALLOUT PARTICLES FROM A TOWER SHOT, OPERATION REDWING ( RESEARCH AND DEVELOPMENT TECHNICAL REPORT USNRDL-TR-208 )
    PHYSICAL CHEMICAL, AND RADIOLOGICAL PROPERTIES OF SLURRY PARTICULATE FALLOUT COLLECTED DURING OPERATION REDWING RESEARCH AND DEVELOPMENT TECHNICAL REPORT USNRDL-TR-170 NS 088-001 5 MAY 1957
    FALLOUT IN THE OCEAN ( STATEMENT PREPARED FOR THE SPECIAL SUBCOMMITTEE ON RADIATION, JCAE, CONGRESS OF THE U.S. FOR PUBLIC HEARINGS ON FALLOUT FROM NUCLEAR WEAPONS TESTS, MAY 5-8, 1959 )
    FALLOUT CONTAMINATION OF FOOD AND WATER
    THE EFFECTS OF HIGH-YIELD NUCLEAR EXPLOSIONS, STATEMENT BY L L STRAUSS
    RADIATIONS FROM FALLOUT AND THEIR EFFECTS BY G M DUNNING
    EFFECTS OF NUCLEAR WAR - BETA RADIATION SKIN LESIONS (BETA BURNS) FROM FALLOUT RADIATIONS
    THE UPWIND EXTENT OF FALLOUT FROM A LARGE NUCLEAR DETONATION (this formed the basis for the simplified treatment of upwind fallout for megaton bursts in the 1962/64 editions of "The Effects of Nuclear Weapons", but it is based on errors; see previous posts on this blog for the problem of the map scales of Bikini Atoll for the Castle nuclear test series reports, which led to all kinds of inherited fallout pattern errors in this and other reports such as DASA-1251 and reports which trust that report)
    A THEORY OF DECONTAMINATION OF FALLOUT FROM NUCLEAR DETONATIONS; PART II METHODS FOR ESTIMATING THE COMPOSITION OF CONTAMINATED SYSTEMS (DELETED)
    PROTECTIVE AND REMEDIAL MEASURES TAKEN FOLLOWING THREE INCIDENTS OF FALLOUT
    A FALLOUT FORECASTING TECHNIQUE WITH RESULTS OBTAINED AT THE ENIWETOK PROVING GROUND
    RADIATION DOSE PREDICTION FOR UNDERGROUND NUCLEAR DETONATIONS
    OPERATION CASTLE, PROJECT 2.7A, RADIOACTIVITY OF OPEN-SEA PLANKTON SAMPLES
    RADIOACTIVE DEBRIS FROM OPERATION IVY ( DELETED VERSION )
    OPERATION REDWING, A PRELIMINARY REPORT OF () ( TEWA ) (DELETED)
    A PRELIMINARY REPORT OF () FLATHEAD ( REDWING OPEARTION ) (DELETED)
    THE BIOLOGICAL HAZARDS OF A FALLOUT FIELD ( REPRINTED FROM RADIOACTIVITY IN MAN )
    FOUR-PI GAMMA IONIZATION CHAMBER DECAY MEASUREMENTS OF FALLOUT SAMPLES FROM OPERATION CASTLE
    TECHNICAL PRESENTATION FOR THE JOINT COMMITTEE ON ATOMIC ENERGY HEARINGS ON THE SUBJECT " THE NATURE OF RADIOACTIVE FALLOUT AND ITS EFFECTS ON MAN " MAY 27-29 AND JUNE 3-7, 1957
    HANDBOOK FOR UNITED NATIONS OBSERVERS, PINON TEST, ENIWETOK (DELETED)
    A PRELIMINARY REPORT OF ( ) ( NAVAJO ) ( REDWING OPERATION ) (DELETED)
    OPERATION IVY, MIKE EVENT CURSORY REPORTS ON EXPERIMENTAL PROGRAMS (PARTIAL) (DELETED)
    OPERATION REDWING, A PRELIMINARY REPORT OF ( ) ( ZUNI ) (DELETED)
    OPERATION HARDTACK, PROJECT 2.8 - AIRCRAFT AND ROCKET FALLOUT (DELETED)
    A HANDBOOK FOR OPERATION CASTLE (PARTIAL) (DELETED)
    OPERATION IVY - PROJECT 8.4 - HIGH-RESOLUTION SPECTROSCOPY AT IVY COMPARED WITH PREVIOUS TESTS, REPORT TO THE SCIENEIFIC DIRECTOR, EXTRACTED VERSION (DELETED)
    THE SHORTER-TERM BIOLOGICAL HAZARDS OF A FALLOUT FIELD
    Other useful documents can also be found there. Another U.S. Department of Energy database is called Opennet https://www.osti.gov/opennet/ and it includes vital declassified reports such as:
    "The Nuclear Radiation Handbook", ASWP-1100, 1957 (nuclear test data on all kinds of radiation from nuclear tests)
    OPERATION JANGLE SUMMARY REPORT: WEAPONS EFFECTS TESTS (contains the vital measurements on the 1.2 kt surface burst Sugar in Nevada, 1951, and the similar yield Uncle underground burst, including measurements of the initial and fallout dose rates continuously since detonation time at various distances upwind and downwind, allowing the two pulses - initial radiation and fallout - of radiation to be compared for different situations, and is also useful for comparison of the fallout arrival times and times to peak fallout dose rate with those from megaton yield tests in the reports for Castle and Redwing fallout characterization studies)

    Pages 56-57 of Edward A. Schuert's 1958 report ADA304431 on 1957 Operation Plumbbob fallout, "Operation Plumbob: Fallout Studies and Assessment of Radiological Phenomena", contain similar (but limited to a single location) plots of initial and fallout dose rates on a single graph for tower shots Diablo and Shasta, e.g.:

    This is useful for giving a feel for how the initial gamma radiation pulse and the fallout gamma radiation dose rates blend together after a nuclear explosion into a double peaked pulse: the time of the minimum in this double pulse of gamma radiation is the time when people can get up to either evacuate the area before fallout arrival, or to take cover and improvise some better radiation shielding in a corner of a building or other shelter (bridge, car park, cave, trench, basement, etc.) that gives the best available protection.
    Yet another useful site for important documents on nuclear weapons effects is now the U.S. Federal Emergency Management Agency, http://training.fema.gov/EMIWeb/edu/highref.asp
    They now host online as PDF files the vital set of U.S. Defense Civil Preparedness Agency (DCPA) manual chapters from 1972, called the "Attack Environment Manual - What the Planner Needs to Know About ---":
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual, Chapter 1: Introduction to Nuclear Emergency Operations. Washington, DC: DCPA, Department of Defense, June 1973. - 14MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual, Chapter 2: What the Planner Needs to Know About Blast and Shock. Washington, DC: DCPA, Department of Defense, June 1973. - 4MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 3 – What The Planner Needs To Know About Fire Ignition and Spread (CPG 2-1A3). Washington, DC: DCPA, Department of Defense. 1973. - 8.9MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 4 – What The Planner Needs To Know About Electromagnetic Pulse (CPG 2-1A4). Washington, DC: DCPA, Department of Defense. 1973. - 2.5MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 5 – What The Planner Needs To Know About Initial Nuclear Radiation (CPG 2-1A5). Defense Civil Preparedness Agency, Department of Defense. 1973. - 1.5MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 6 – What The Planner Needs To Know About Fallout (CPG 2-1A2). Washington, DC: DCPA, Department of Defense. 1973. - 7.2MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 7 – What The Planner Needs To Know About The Shelter Environment (CPG 2-1A7). Washington, DC: DCPA, Department of Defense. 1973. - 8MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 8 – What The Planner Needs To Know About The Post-Shelter Environment (CPG 2-1A8). Washington, DC: DCPA, Department of Defense. 1973. - 5MB PDF
    Defense Civil Preparedness Agency. DCPA Attack Environment Manual: Chapter 9 – Application To Emergency Operations Planning (CPG 2-1A9). Washington, DC: DCPA, Department of Defense, 1973. - 5MB PDF

    1 Comments:

    At 3:50 pm, Blogger T. said...

    Dear Author,
    I find myself fascinated by the photo of the SAGE panel Aug. 1966. One of the gentlemen in the photo bears a striking resemblance to my grandfather. Were this to be true, this would represent a watershed moment that would link many odds and ends that I have been attempting to unravel for the last two plus years. Can you provide names to the faces and/ or source of the photo? Any other info you have that may not be in the blog?

    Thanks.

     

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