UCUASSIFIEN Safety Plan. wm. Suitable instrurents indic fe intensity of radiouctivity at a given place. inves reconnaissance, thw maine tenance of contanination situntion maps, the pesting of arvas of hagard, and minimizing the scread of contaminated material inte uncontsminated arvas, constitute the active measures for reducing the radiolegical hezard. 2. SNTICTPATED Hi2ARPWS REIS a. Icmedtately under the bomb burst them: will be sn aroa of dsrgvrous radioactivity about five hundred (500) yerds in rodius. Some residusl radio- activity will be observed at greater distances. be Rear the point of detonation and downwind, an airberme radioactive hazard will exist. Its cheracteristics will depend on the meteorclogical irfluences such as wind speed and dimction et verious altitudus up to the caxtimum twight reached by the cloud. ce Contazinated water from the Legoon will move in sccerdance with prevail- ing water currents, This will probably not offer any serious hazard but will require checking and may interfere with sone operations. d. All individuals or objects entering contaminated arvas may transfer hazardous radiosctivity to clean anas. Exatples arm the drones sespling tho cloud and personnel entering contaminated areas to collect instrunents. «. By means of instruments, such as “wigvr-Kuller counters and ion charbers, it is possible to detect the aruns of contanination and to seasum the intensity of the radioactivity. Radiation intensity will be measured end reported in roentecns por twenty-four (2h) hours, Sesides these instrumnts, desiaeturs and film badges will be used as indicators of the accunultted exposun to ridice ectivity. Persennel will wear film drdgvs to provide a permanent record of the exposure. f. The intensity of the radioactive hazard tend to decrease with time due to (1) decay of radionctive gatertals, and (2) dispersion, dilution, md trans~ ference from the immediate site. 4s an approximation the intensity of the rad- dation fran the fission products ducrvases by radioactive decay inversely with tho time after the detonation so that an arva which had 15 rowntguss per hour at one (1) hour after detonation would have an intensity of 7.5 roentgens at two (2) hours after detonation and 5.0 roentgens at three (3) hours. v. NUP RAs, 6.