I was listening to the news this morning, and they were talking about how it was a (relatively) good thing that most of the discharge from the Japanese nuclear plant was from one of the reactors. They knew this, because most of the release from the plant was Iodine-131, which has a half life of only 8 days. That means nearly all of the I[sup]131[/sup] would have decayed out of the environment in a matter of months.
If the release had come from the storage pools, it would have consisted of Cesium-134, which has a half-life of about two and a half years. That would stick around for much longer.
Yay… I guess.
Now my question.
What does U[sup]235[/sup], the primary fuel of a nuclear, reactor fissure into?
2 protons and 2 neutrons is an alpha particle. Some heavy elements (uranium, thorium, etc) emit them as part of the decay process.
A beta particle is an emitted electron created when a neutron is converted to a proton – free neutrons do this spontaneously with a half-life of about 15 minutes; neutrons in some nuclei do it at various speeds depending on just how unstable the nucleus is.