Chopter /
INTRODUCTION
1.1 OBJECTIVES
The objectives of this project were to: (1) understand the oceanography of the fallout area,
so as to allow better analysis of the fallout area; (2) determine by oceanographic methodsthe
intensity and extent of fallout andconvert this to land-equivalent values; (3) study the circulation
water within Bikini Lagoon and predict the movementof the radioactive material suspended in
the lagoon; (4) install and maintain anchored instrument stations in deep ocean water; and (5) perform radiochemical analyses on as wide a scope as possible with equipment on hand.
In achieving these objectives, it was hoped that enough information concerning the study and
measurement of fallout at sea would be gained to permit a reduction in the number and types of
measurements required to describe the fallout phenomena under various conditions of detonation.
It was also anticipated that the early determination of the initial fallout distribution would be
valuable to other agencies making long-range studies of the radioactive water mass.
1.2 BACKGROUND
The existence of fission-product problems —control, disposal, and fallout— were recognized
virtually simultaneously with the discovery of fission. Various plans to safeguard test personnel
and adjacent citizenry have been a part of all test programs since Operation Trinity. For shots
in the 20-kt range, fallout was scarcely more than an added overkill on targets already heavily
damaged by thermal andblast effects. An early exception was Shot Baker, Operation Crossroads,
in which a highly contaminating test against refractory targets gave evidence of the added offenSive value of fallout materials. The high-airburst geometry of many tests, including the Japanese attacks, precluded much attention to fallout.
It had long been apparent, however, that fallout-radiation intensities increase with some
fractional power of the total yield for weapons having the same percentage of fission yield. Any
fallout model is complicated by the natural conditions of atmospheric circulation; and at the time
of Shot Mike, Operation Ivy, exploration of mathematical and analogue models was more popular
than extensive field studies, and only a cursory fallout study was included in the weapon-effect
Program of that shot. Though extremely contaminating, Shot Mike was carried out without conSpicuous evidence of the fallout potentialities, with the negligible exception of the experience of
the Scripps Institution of Oceanography (SIO) reaearch vessel, the M/V Horizon (Reference 1).
Operation Castle included a more thorough investigation, consisting of manned and shielded
Vessels and free-floating telemetering collectors. Shot 1 illuminated the severity of the fallout
Problem.
Following a hastily-mounted survey for Shots 5 and 6 of Operation Castle (Reference
Redwing,
The specific historical background of the methodology is reported in the appropriate
2) and other experiences (Reference 3), the work, reported herein, was envisaged for Operation
individual chapters,
A Particularly valuable innovation in Operation Redwing was the organization of the Program
Ontrol Center, from which all survey elements of the fallout program were directed and