n R shallow water crest height in feet Ni} where H, range in feet W = equivalent charge weight in megatons + angular breach width in degrees in a semicircle into the lagoon p = relative density of media beneath fireball 2.3.2 Program 2, Nuclear Radiation Effects The general objective of this program was the determination of the militarily significant nuclear radiation effects of high-yield surface detonations. Of primary interest was the determination of the nature, intensity, and distribution of radioactive fall-out resulting from surfaceland and surface-water detonations of high-yield devices, In addition, the effects of initial gamma radiation and the flux and spectrum quality of neutrons were investigated. Gammafilm- and chemicai-dosimetry techniques and gamma scintillation-counter equipments were employed to evaluate initial and residual gamma-radiation exposure and to provide information on arrival tirne and early field decay characteristics of gamma radiation fromfall- out.T.. vee ee ee eeee ee ne - The fall-out instrumentation included a variety of types of collect +s, inclut.: samplers “yr total Noaid and dry fall-out colection, intermittentt collectors, ab Dowd arr sul collectors. “ne lagoon and island areas localto the she: cero points were heavily iste ines da for all C operation Castle detonations| , Documentation of fall-out over extensive downwird scan arcs +. suit red serious ex- perimental and operational difficulties. The problem was attached initially b byt! the employment of an array of free-floating buoys equipped with sample collectors. an area survey was mounted which involved surface and subsurface activity moasuncimenerWater sampling, and hydrographic measurements. This survey covered a broad downwiid zone to a distance of 200 miles and met with a large measure of success. __Neutron-flux measurements e ; stablished the natureand“magnitude of theseeffects for these types of high-~yield surface detonations. Initial gamma radiation and neutrons are of minor significance in relation to other effects of such bursts. Considerable information was cbtained on the distribution and characteristicsof fall-out from high-yield land and water surface detunations. Extensive close-in data 4 augmented by a postshot survey of ramerous downwird islands within the path of thefall-outto a range of 300 miles. The oceanog-eaphie and radiolugical survey provided good coverage of the principal zone of downwind fall-out to a range of 200 miles. The results of the latter, plus limited good buoy sampies taken 35 to 50 miles downwind __ , should allow - ev aluation of the nature and distribution of fall-out for high-yield surfaces ater bursts, These results indicate that surface bursts of megaton yields @ietribute canualty-producing fall-out over areas upwards of 1600 square miles. __Yindic ates that the tech: pues en: i yed, coupled with The oceanographic survey[_ a rapid synoptic monitor surveyof the water surface by fast surface vessels or nircraft or both, provide a feasible method for ducumctntation of fali-out over water areas, 2.3.3 Program 3, Stractures The objective of Program 3 «5 to study the wie ef blast in serious areas of military interest. The nature and results of this study are tri fed th Cae fdiowing parayge aphs. j detonation In Project 3.1 a rigid 6- by 12- by €-ft cubicle oto: GO ft froin thef sere obtained, but Records faces, wiocle ¢ the mn time vs e pressur record to was instrumented abhi to tad Leen exthe pressure field was on the order of 3.5 psi instead .f the order af Wopst apdiinterprcted, pected on the basis of predicted yield, The data are yet fe be a: wiyred 22