Originally Posted by Saquist
Radiation comes in essentially 3 different varieties.
and Gamma Radiation.
Alpha radiation is extremely weak and can be blocked by a sheet of paper. The radiation from the aftermath of of the Nagasaki and Hiroshima detonations is this type. It last a very very long time but it's extremely weak.
Beta Radiation, is stronger than alpha and weaker than gamma radiation. Usually another type of radioactive decay from isotopes. It's penetration is more powerful and can be stopped by a few millimeters of aluminum. This is the type of radiation coming from the sun on average. Highly charged and blocked by Ozone and the Earth's shields.
Gamma Radiation is a higher frequency form of the above. In a nuclearly detonation this is part of the initial flash point, or in super nova's it is the first sign (other than neutrinos) of an explosion. They are short lived but their high frequency allows them to penetrate just about the most densest material.
The sun can put out GRB's in CME's (coronal mass ejections) but this is not common and it's a direction blast so spacecraft have to be within the line of sight of the burst.
Those 3 are specifically known as ionizing radiation. There are 2 other forms of ionizing radaition: neutron and x-rays.
Beta particle shielding can actually be tricky due to the Bremsstrahlung effect. When passing through a metal barrier, beta particles decelerate. Conservation laws dictate that the energy lost by the particle must go somewhere. This happens by emitting x-rays. This is how x-rays are generated in a x-ray tube. I suspect as long as you aren't being constantly bombarded by beta particles then it's not as big of a deal.
There is also non-ionizing radiation such as microwaves and visible light to name a few.