HEALTH PHYSICS CONSIDERATIONS IN PROCESSING TRANSPLUTONIUM ELEMENTS

The radiation hazards of elements 95 through 99 (americium-einsteinium) are compared with 239Pu. Most of the transplutonic nuclides decay by alpha particle emission and have higher specific activities than 239Pu. This increased specific activity creates potentially greater contamination control problems, greater alpha-neutron reactions, and more X- and gamma-rays per unit mass than experienced with plutonium. The spontaneous fission half lives of these radionuclides are orders of magnitude shorter than for 239Pu, leading to prompt fission neutron and gamma exposures not heretofore encountered. Disregarding fluorescent radiation, the combined gamma and neutron dose rate from tens of kilograms of 239Pu is equivalent to that from grams of 244Cm, tenths of grams of 241Am, and only micrograms of 252Cf. The transplutonium elements provide a unique combination of hazards—high radiotoxicity, external exposure potential, and criticality—which makes their control a challenge to the practicing health physicist. © 1969 Health Physics Society.