Email to Piotr Bein 27.3.2011
A uranium alpha particle packs a punch of 4.5 MeV (Million Electron volts) a Pu alpha particle has 5.8 MeV’s.
LET – Linear Energy Transfer – energy transmitted into the mass of cellular material from radiation.
Alpha, beta and neutron radiation are particles – that is, they have mass. Alpha and beta are charged, negative or positive, while the neutron is neutral – no charge.
They transfer energy and charge in the form of heat and kinetic energy of velocity X’s mass and this ionizes (smash) cellular materials.
One MeV is 1.602×10−19 Joules and that is a huge heat impact at the cellular level
Gamma also tranfers substantial energy but it is not a particle, it is a light photon – virtually pure energy, travelling just under the speed of light.
Depending on the species of Pu, the reactor Pu and its daughters have a specify activity of .005 to 110,000,000 Ci/gr. Compared to Uranium’s (depending on species) of .006 – .00006 Ci/gm
What this says it that the biological effect (damage, ionization of the cellular material and DNA etc.) of one decay of U is not too much different than one decay of Pu (4.5 vs 5.8).
BUT if we compare the total radioactivity of U to Pu … for example if one inhales the exact same sized particle of each nuclide, Pu has thousands to millions of times more emissions in the same time period. So while the damage from U and PU alpha radiation particles is basically the same due to transfer of energy into cells, Pu with its decay daughters Np and U234 will cause about 110,000 times the number of points of damage than U.