Operation Redwing - Project 2.61, Rocket Determiantion of Activity Distribution Within the Stablized Cloud (Deleted)

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Rocket Determination of Activity Distribution Within the Stabilized Cloud Pacific Proving Grounds Headquarters Field Command Defense Atomic Support Agency Sandia Base, Albuquerque, New Mexico This is an extract of WT-1315, Operation REDWING, Project 2.61, which remains as of this date. Extract version prepared for: DEFENSE NUCLEAR AGENCY Approved for public release;

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Operation REDWING - Project 2.61 Rocket Determination of Activity Distribution Within the Stabilized Cloud 1PERFORMIMGORCANI ZATIOM NAME ANO ADORES$ U.S. Naval Radiological Defense Laboratory San Francisco, California ‘&~LIMG OFFICE NAUE AND AODRESS Headquarters Field Command Defense Atomic Support Agency Approved for public release; unlimited distribution. [his report has had the classified information removed and has ~nclassified form for public release. This work was performed by Kaman Tempo under :ontract DNAOOJ.-79-C-O455with the close cooperation of the Classification Radiation Intensity Data

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This report has had classified material removed in order to make the information available on an unclassified, open publication basis, to any interested parties. This effort to declassify this report has been accomplished specifically to support the Department of Defense Nuclear Test Personnel Review (NTPR) Program. The objective is to facilitate studies of the low levels of radiation received by some individuals during the atmospheric nuclear test program by making as much information as possible available to all interested parties. The material which has been deleted is all currently classified as Restricted Data or Formerly Restricted Data under the provision of the Atomic Energy Act of 1954, (as amended) or is National Security Information. This report has been reproduced directly from available copies of the original material. The locations from which material has been deleted is generally obvious by the spacings and “holes” in the text. Thus the context of the material deleted is identified to assist the reader in the determination of whether the deleted information is germane to his study. It is the belief of the individuals who have participated in preparing this report by deleting the classified material and of the Defense Nuclear Agency that the report accurately portrays the contents of the original and that the deleted material is of little or no significance to studies into the amounts or types of radiation received by any individuals during the atmospheric nuclear test program.

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This report presents the finai results of one of lheprojectsp anticipating mthe miiitary-effect programs of Operation Redwing. Overall information about this arid the other military-effect projects can be obtained from WT- 1344, the “ Summary Report of the Commander, Task Unit 3.” Th!s technical summary inciudes: (1) tables listing each deton.ition with its yield, type, environment, meteorological conditions, etc.; (2) maps showing shot locations; (3) discussions of results ty programs; (4) summaries of objectives, procedures, results, etc., for all proj - eels; and (5) a llsting of project reports for the military-effect programs,

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Forty especially developed atmospheric-sounding projectiles (ASP) were fired through the clouds resulting from Shots Cherokee, Zuni, Navajo, and Tewa to proof test a system for measuring gamma intensities within the clouds and to mcplore the spatiai distribution of gamma activity within the stem and cloud resulting from the detonation of a nuclear device having a yield in the megaton range. Radiation intensity information was successfully teiemeiered out of the radioactive clouds by the ASP rockets and recorded on magnetic tape. Radiation intensities as high as 3 by 10’ r/hr were encountered within the cloud; intensities at the one measured point in the stem were negligible compared to the peak activity within the cloud. Contamination of rocket surfaces by radioactivity from the cloud did not appear to be of consequence. Total activities in the clouds computed from rocket data agreed in order of magnitude with activities derived from theoretical considerations.

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This project was undertaken as a joint effort by members of the U. S. Naval ILictiological Defense Lr.bora:ury \USNRDL) and Cooper Development Corporation of Mjnrovia. California. The responsibilities of Cooper Development Corporation were ctefined in Bureau of Ships Contract, No. NObs 72000. These Lncluded respons~bilities for the design, deveiopmen’, and testing of the rockets used in the project, firing of the rockets In the field, recording of dda from rockets fired Ln the fieLd, and reduction of data. NRDL furnished field personnel. :ncludir,g a project officer, and was responsible for interpreting the reduced data as pl-esented ti~ the contractor. The proJect officer extends his thanks and apprec iaLLon to those ,ndlviduals and groups who thr~ugh their cooperation and assistance contributed materially to the >uccessful completion of the project. Their specific contributions are cited as follows: H. R. Wasson of L?SNRDL, who offered technical advice and assistance in the desgn and testing of the rad~ation transducer; tion transducer, offered technical advice and performed the field calibration of the lr.struments; Captain and crew of the USS Knudson, APD-1OI, who assisted 111the installation and operation of the shipboard telemetering receiving station; and Commanding Officer znd men of Detachment A, Mobile Construction Battalion 5, who assisted in the ir.stallatiol] of the rocket launching station ancf the Site Nan receiving station and performed the technical survey ‘sork.

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4.3 Contamination of the Rocket --------------------------- Energy and direction response oi ASP radla!~on transducer -------- ----

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Typical roentgen information versus time pl~t for Shot Cherokee, Typ:calroentgen information versus time plot for Shot Cherokee, Concentration of gamma emitters to produce 1 r/hrfield inan Activity distribution in the plane of rocket trajectories 7 minutes Activity distribution] in the plane of rocket trajectories 1S minutes after Shot Cherokee -------------------------------------- Activity distributi~n in the plane of rocket trajectories 7 minutes Activity distribution in the plane of rocket trajectories 15 minutes Activity distribution Ln the plane of rocket trajectories 15 minutes Reproducibility of similar rounds firecf 15 minutes titer Shot Navajo -------- Comparison of sLmiiar trajectories during Shots Cherokee and Tewa ------- -- 2.1 Range and Bearings of Shot Points from Receiving Stations and 3.1 Summary of Launch Condit~ons for Shot Cherokee --------------------- 3.2 Summaryof Launch Conditions fcr Shot Zuni ------------------------ 3.3 Summary of Launch Conditions for Shot Navajo -------------------- --- 3.4 Summary of Launch Conditions for Shot Tea --------------- --------- 3.5 Su,mmary of Ioformat ion Telemetered from Various Rockets 3.6 Summary of Information Telemetered from Various Rockets 3.7 Summary of Information Telemetered from Various Rockets 3.8 Summary oi Information Telemetered from Various Rockets 3.9 Rocket Contamination from Various Shots --------------------------- 4.1 Comparison] of Theoretical and ExpelmentaI Estimates of

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The specific objectives of Project 2.61 were to: (1) proof test a system using rocket-borne detection units with telemetering trmismitters to explore the spatial distribution of radioactivity m the stem and cloud resulting from a imc Lear detonation; (2) measure gamma intensities along several continuous known trajectories passing through t~e stem and cloud at ‘7and 15 minutes after detonation; and (3) estimatr the extent to which the rocket became contaminated as it passed through the stem or cloud. 1.2 BACKGROUND AND THEORY Although various mathematical modeis for the fallout process have been presented (Reference 1), gross differences exist among the assumptions as to spatial distribution of radioactive emitters in the cloud and stern. Determination of the distribution which actually exists is essential to the development of a correct model and the eventual reaiistic predictions of fallout patterns. Without such knowledge there wouid be continuing uncertainties as to the spatial positions of active particles prior to fall, resulting in unrehabie predictions cf the spread and extent of ac - tivity, Besides being essential to the development of fallout theory, a knowledge of the distribution of radioactivity In the cloud and stem at early time& may be important for interception, countermeasures, and long-range-detection studies. Construction of an effective fallout model requires knowledge of the size, activity, and spatial distribution of radioactive particles in the stem and cloud. Of these parameters, particle size distribution and related activ Lty were determined from particles collected as fallout at the surface of the earth by Projects 2.63 and 2.65. If, in addition, measurements of gamma intensities in the stem and cloud are made, gross distribution of active particles in the stem and cloud may be inferred. Restrictions due to time and equipment available before the ~peration precluded measurement by this project of any parameter except gamma activity as a function of time and Measurements of radiatiol fields existing in clouds resulting from detonations of devices in the kiloton range have been made previously. The first measurement of cloud-radiation fields was made during Operation Greenhouse by the use of drone aircraft. These measurements were made in the stems of clouds resulting from explosions whose yields ranged from rFieids of a~out 104 r/hr were observed at 3 to 5 minutes after detonation and of abou~ at 30 minutes after detonation (Reference 2). During Operation Upshot-Knothole, canisters and drone a;lrcraft operated in the mushroom tops resulting from 11 tc, 26 M explosions. Fields of about 104 r,’hr existed at 2 to 6 minutes after cletonat ion (Reierence 3). During Operation Redwing, aircraft were flown through the stem and lower portion of six clouds resulting from detonations in the megaton range. Reference 4 gives as the average dose rates encountered when corrected to 100 percent-fission yield:

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t = time after detonation, minutes This equat~on yields 3,700 r/hr and 1,000 r/hr as the average dose rate to be expected at 7 minutes and 15 minutes from a 100 percent-fission yield device. A vehicle, capable of carrying a radiation detector and telemetering equipment to at least the top of the highest cloud expected, was required to explore the spatial distribution of gamma activity in clouds resulting from multimegatoil detonations. It was desirable that the vehicle be able to pass weli out of the top or side of the cloud, so that an indication of the contamination of the vehicie could be obtained. Because of the altitudes involved arid turbulent conditions existing at early times, manned or unmanned aircraft couLd not be used to measure activity withtn the higher regions of the cloud resulting from a megaton range device. The above, along with considerations of expense and logistic problems, indicated that a single-stage, rocket-propelled ballistic missile wouid serve best to carry the detector and telemetering equipment. To serve as a basis of comparison for the activity distributions as determined by the rocket flights, theoretical estimates were prepared of the number of photons per second present at 7 TABLE 1.1 THEORETICAL ESTlhlATES OF CLOUD ACTIVITY Time Contributor Cherokee Zuni Navajo and 15 minutes after detonation (times at which the rocket measurements were made). The contribution to the total activity of the device components only was considered. The fission product activity, based on the slow neutron fission of UZ3S, at 7 and 15 minutes was found to be respectively (Reference 5). At these early times, the induced activity contribution of UZJ9was considered. Other induced activities with gamma energies in the range that can be measured by the rocket transducer could possibly add around 5 percent to the activities tabuIated in Table 1.1 depending upon materials used in the construction of the deless than 1 percent of the activity due to the fission products. For capture-to-fission ratio of 1.0, the calculated activities of U23gat 7 and 15 minutes were 4.0 d/s/104 fissions and 3.2 d/s/104 fissions, respectively. Applying directly the capture -to-f ission ratios 0.500, 0.427 and 0.125 as determined from actual samples obtained during Shots Cherokee, Zuni, and Navajo,thecontribution of U2~Sto the total activity for the various events was then determined. The use of theoretnumber of photons per disintegration for the fission products, 1.19, and U2S$, 0.83, and the number of fissions per kiioton of fission yield, 1.45 x 1023 together with the d,/S/ 10” f ission~ ‘alues for the fission products and U2$9then yielded the actlv~ty per event in photons/second at specified times. The data obtained are presented in Table 1.1.

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The project participated in Shots Cherokee, Zuni, and Navajo (ah’, land and water detonations, respectively) and to a limited extent in Shot Tewa (a surface detonation over shallow water). The original intent of the project was toparticipatein Shots Cherokee, Zuni, and Navajo only. liowever, since there were four rockets (spare units) remaining at the conclusion of the Navajo event, the decision was made in the field to fire them during Shot Tewa. Forty rockets and radiation tratlsducers with accompanying telemetering gear were used. Thirty-six rockets were fired for Shots Cherokee, Zuni, and Navajo. Twelve rockets were fired in two salvos of six during these events. The first salvo was fired at 7 minutes and the second at 15 minutes after detonation with 2-second mtervaIs between rockets of each salvo. The four additional rockete were fired during Shot Tewa at 7 minutes after detonation with 10second intervals between them. For Shots Cherokee, Zuni, Navajo (second salvo), and Tewa, the rockets of a single salvo had different trajectories in a single vertical plane. For Shot Navajo, the six rockets of the first salvo were fired at the same quadrant elevations but at different azimuthal angies. Trajectories were determined before the detonations on the basis of predicted winds. Some rockets were fired so as to pass through the cloud or stem into a radiation-free area while their signals were stiII being received, so that the contamination of the rocket could Fifty units of an especially developed rocket were produced for this operation. The radiation transd~cers, likewise, were especially developed. Commercial equipment served as the transmitting and receiving units. 2,2.1 Rockets. Prior to the acceptance of the proposal for this project, there was no singlestage, soiid-fuel rocket that could attain an altitude of 100,000 feet when launched from sea level. Design, fabrication, and testing of the rocket was accomplished by Cooper Development Corporation, who also had the responsibility for launching the rockets and recording their data in the field. The result was a 6~t-inch diameter by approximately 12-foot-long rocket capable of attaining a maximum altitude of about 200,000 feet or a maximum range of about 230,000 feet. The radiation detector and telemetering transmitter were located in the ogive (head assembiy). Figure 2,1 is a schematic drawing of the rocket, missile using a solid fuei. The single-grain propellant consisted of a stabilized ammonium perchlorate oxidizer with a Thiokol base. The single-stage motor had a totai imPulse of 31,000 lb-see and a burning time of 5.8 seconds. The burnout velocity of the rocket was approximately 5,400 ft/sec. The prelaunch weight was 245 pounds with a burnout weight of 93 pounds. Rockets were launched from a simple rail-type launcher employing a zero-tipoff system. Figure 2.2 shows one set of rockets on their iaunchers at Site How. In this zero-tipoff launching system, as a rocket moves forward, it is supported on the raii by two launchlng shoes. AS the forward shoe leaves the front of the rail. it drops free of the rocket, and the after shoe m sheared off by a biock on the launcher raii, permitting the rocket to continue to move para~lel to the rail without tipoff error.

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The rockets were caged in position on the launchers during all events until the shock wave passed. In Figure 2.2, all rockets were caged except the one in the lower right-hand corner, on which the …