t O Tt 3/1.3/32m8 8. In order tobe able’to contime to carry out CASTLE requirements, CTG 7.3 has requested: Commander, Joint Task Forée SEVEN to increase the Maximum Permiss~ ible Exposure for Operation CASTLE to 7.8 roentgens: (AEC allowed exposure for 26 weeks) for (a) Helicopter pilots and plane captains, (b) Boat operating personnel of Task Group 7.3 boat pool, (c) Flight deck crew of the USS BAIROKO, and (d) Personnel attached to the USS PHILIP, approximately 490 persons, in alle In the interest of efficiency and econony, this command has also recommended to Commander, ‘ Joint Task Force’ SEVEN that personnelnot be relieved.or detached from TG 7.3 units! due to radiation, unless their accumulated exposure exceeds or approaches,7.6R, This command is endeavoring to employ persons with high exposure in activities — where they will receive little or no additional exposure, insofar as practicable, 9, Since BRAVO was detonated on a reef, the subsequent contamination: of ships’ by ' solid particles rather than water droplets, is not what ordinarily would be expected in naval atomic warfare on the high seas, although contamination by solid particles could be expected on ships in harbors or near land, Consequently, som of the following remarks, on damage control measures have somewhat limited mt application in naval atomic werfare,. 4 &@. Especially in locations near (within about 50 miles of) ground zero, it is essertial that damage control measures, intluding washdow, be placed in effect before and not after the fallout begins to reach the ship. This conclusion is: . « based on BAIROKO's experience that in such locations fallout tutilds UP very oe rapidly, (fron 0.2 mr to 1R in less than 5 minutes), be. Presently installed vashdown systems using fine spray are only partially ° effective in removing relatively heavy, visible, solid particles, Heavier sprays or hoses with a large volume of water are mcessary to effectively remove these, * particles. Further, improvementsin drainage are desirable to Temovethe large. volumes of water required. oo \ Oe . . ce. Presently installed washdown systems are most effective when heading inta® the wind, Cross-wind headings result in much of the spray being blown from-the ships structuré. Zig-zagging helps in wetting all topside areas ami in facklit. ating drainage. d. Oo Special measures, including more extensive washdow equipment and drainage, are necessary on bridge structures (especially horizontal etacesy where critical command pef#sonnel normally are stationed, Commanding Officer BATROKO received a relatively high dosage while conning his ship on 1 March, 10. The presently prescribed mehtods of decontamination, both material and personnel, were found to be effective. ll. The excellent report from BATROKO, enclosure (4),» is considered worthy of special mention. It is believed that BAIROKO, -ESTES and PHILIP were the first active ships in the Navy to be exposed to radiological fallout on a relatively heavy scale, === ead ‘