The maximum energy that a beta particle can reach is 606 keV .
The beta particles , due to their high mean energy ( 190 keV , with typical beta-decay spectra present ) have a tissue penetration of 0.6 to 2ï¿½mm.131I is a fission product with a yield of 2.878 % from uranium-235 , ( thermal neutron fission ) and can be released in nuclear weapons tests and nuclear accidents .
Iodine-131