NAV NBC 3 NUC A.  24 D.   201405Z F.  5600N  01115E N.  10  KT Y.  01000140  DEGREES Z.   01000804 NBC 3 NUC A.  24 D.  201405Z F.  32VLB  126456 N.  10  KT Y.  GRID  17782489  MILS Z.   01901508 Description of Elements A.  Strike  serial  number. D.  Date-time  of  strike. F. Coordinates of blast. N.  Weapon  yield. Y.   Clockwise   direction   of   left fallout  radial  (4  digits),  then  the right fallout radial (4 digits). Z.   Effective   downwind   speed   (3 digits), Zone 1 downwind distance (3  digits),  and  the  cloud  radius  (2 digits). N N N N N N N N NOTE: When the wind speed is less than 8 KPH (5 knots), the Zone I downwind distance in element 'Z' will be reported in only 3 digits, which is the radius of the Zone I hazard from GZ. Figure 5-4.—Example of the contents of NATO reports NAV NBC 3 NUC and NBC 3 NUC effective downwind messages. also contains evaluated information on the detonation, of time. Contaminated areas will remain radioactive for including weapon yield, effective fallout direction and a  considerable  period  of  time  on  land,  but  the speed,  and  cloud  radius. contamination is dispersed rapidly over water areas. An  NBC  3  NUC  message  of  effective  fallout downwind  speed  and  direction  for  ground  forces  is called  an  Effective  Downwind  Message.  In  this message,   locations   are   given   in   UTM   coordinates, angular measurements in degrees or mils, distances in kilometers,  and  speeds  in  kilometers  per  hour.  See figure  5-4. PLOTTING  RADIOLOGICAL  FALLOUT AREAS In the ATP-45, nuclear fallout is grouped into three categories: The quantity of fallout released by a blast is directly proportional to the size of the blast—a low-yield blast produces less fallout than a high-yield blast, and by the height of the blast. A high-air burst produces very little fallout,  a  low  air-burst  produces  some  fallout,  and  a surface-burst  produces  great  amounts  of  fallout.  At  sea, a  subsurface  burst  produces  less  fallout  as  the  depth increases,  with  negligible  fallout  if  the  fireball  does  not break  the  surface.  The  effects  of  a  nuclear  blast  are discussed  in  detail  in  your  Basic  Military  Requirements course,  as  well  as  in  Military  Requirements  for  Petty Officer Third Class. Immediate fallout—heavy debris deposited near ground zero within 1/2 hour of the blast. Medium  Range  fallout—debris  deposited  from 1/2 hour to 20 hours after a blast, up to hundreds of miles from g-round zero. Figure 5-5 Shows a typical NATO fallout plot. The + marks the point where the weapon will be or has been detonated, identified by the letters  GZ  for  ground zero. Long   Range   fallout-very   light   particles   that remain  suspended  in  the  atmosphere  from  20 hours to several years. Fallout is deposited over a very large area of the earth’s surface. The   NATO   Nuclear   fallout   warning   areas discussed  in  this  chapter  show  only  the  areas  that receive   immediate   and   medium   range   fallout.   The hazard to people in contaminated areas depends on the concentration of fallout, the amount of time the person has  been  in  the  contaminated  area,  and  the  total radiation the person has been exposed to over a period Figure 5-5.—NATO fallout plot. 5-5