1955 Tnstribution of Radioa~t vit, 11 ve Sea around Bikini 99°, of the radivactivity passed through a hiter paper 255 pore size 0.5 4, No.4 Filter Paper, Tay" Filter Paper Manufacturing Cu.. Pokyo . It 18 rather surprising that the activity in sea water near Bikini and Eniwetok Atolls was often stronger than, or at least comparable to, that of White Oak Lake receiving waste eue:? from nuclear reactors of Oak Ridge National Laboratory (SA. The latter was 2710~5190 cpm per litre on an average [2]. The distribmtion of radioactivity in sea water around Bikini Atoll a Hors «4. tietribution . snows the horizontal distributian of the acti.ity in the surface water’ oar ctrainy Atoll There must have been some changes in the activity due to the Jue variation uf the sea condition, the natural decay oind the lose of the radiu activity during “ “ ¥ observational data without giving «any correction. As shown in Fig. 3 the radioactive water extended on the WNW direction leaving near Bikini Atoll ing But, i8 as not clear. explained below, it seems that there was a weak discontinuous boundary along the line . f 5 Sa Pee oY “ “ “9,0 lif. - 0. “y eT + ~ i < Sperm ve a * Te eslDliie at ~ 1 + — ~ —— - ‘uh om a Fig 3 The horizontai iistr’ bution of “the radioactivity of the surface Water Namber expressea the radioactivity in opm, / SOE —7 yn ao SL, \ ES" 70k doi. -+-+-- —~ 2 ~ak 4 a a. : ee -—atN j while a branch spread out to WSW. The cause of this branch- 70" —- -~-- aM o> Se . Ep° cated, and the cor rectian were almost impossible, the distribution was drawn by using directly the ~ ~ ‘the course of vJ0dser\a.tion. However, since the causes of change aete much compli. ve eet RE 3. Rn 4 7 . we A yy tee -- ep ‘54 ' 5, 1 RT een me Ne eeov WN8G se si passing Bikim and Eniwetok Atolls. The water 27, (Fig. 4) on the northern side of this ‘ine had on an average the Fig. 4. The couree lines of observation, the water systema, and the current speed and its cirection. 27