Yeah, but you have to remember that when it comes to what they say is is the limit, vs what rad-levels you can absorb and still survive is really safe-sided.. Decay rate for gamma radiation is pretty constant, and if you follow the "7-10 Rule", you'll see that it's as bad as made out to be...
The "7-10 Rule " is that for every seven-fold increase in time, there's a ten-fold decrease in the rad-level (This applies to Gamma and Neutron Radiation, BTW) and that's the good news.. If the Gama ray level is say, 100,000 cGy (Centigrays, same value as RADs,, or Radiation Absorbed Dose) per hour at H-1 (That's one hour after the burst), at H+49 (a seven-fold increase in time), the dose-rate will be 10,000 cGy per hour (a ten-fold decrease in radiation)...
.. Gamma rays pass through objects and keep going, in a straight line, while Neutron, even though they're the only type of rays that will make other things radioactive, will be blocked (and absorbed), and these are the really bad ones.. However, Neutron particles are formed by a nuclear detonation, from either type of weapon, fission or fusion, and although they can be formed at a reactor, they don't have the concentrations that are considered lethal unless you're right AT the reactor location... They don't travel well as fallout. and are generally absorbed by things around the emitters...
Fallout, which is basically dust & dirt with particles attached to them, is more hazardous as a source of Alpha and Beta partcles, and Alpha particles are an inhalation or ingestion hazard, since they're blocked by the skin, and their range is only about 2-4 centimeters and can't get through a layer of skin and fat cells.... Beta particles cause radiation injuries to the skin, or internal organs if ingested or inhaled (Beta Burns)...
But in a nutshell, the rad-levels are set really high, becasue they're dangerous eventually, no matter how low the dose-rate is, and 60, 70, or 80 years later, you die from melanoma or something... But at least you won't glow in the dark...