Radiation Effects in Organic Compounds Summary

DOE-HDBK-1017/2-93 RADIATION EFFECTS IN ORGANIC COMPOUNDS Plant Materials TABLE 3 Radiolytic Decomposition of Polyphenyls at 350 � C Material G (gas) G (polymer) Diphenyl 0.159 1.13 Ortho-terphenyl 0.108 0.70 Meta-terphenyl 0.081 0.64 Para-terphenyl 0.073 0.54 Santowax-R* 0.080 0.59 * A mixture of the three terphenyls plus a small amount of diphenyl. An effect similar to that described above occurs in water molecules that are decomposed by radiation into hydrogen and oxygen in a reactor. Control of oxygen produced by this process is an important part of reactor chemistry. Summary The important information in this chapter is summarized below. Radiation Effects in Organic Compounds Summary Gamma and beta radiation have little effect on metals, but break the chemical bonds and prevent bond recombination of organic compounds and cause permanent damage. Radiation causes changes in organic materials. Nylon has a degradation of its toughness at relatively low doses and little loss of strength. High-density (linear) polyethylene marlex 50 loses both strength and ductility at relatively low doses. Typically rubber increases in hardness when irradiated. Butyl or Thiokol rubber soften or become liquid with high radiation doses. The chemical bond with the least amount of resistance to radiation is the covalent bond. Polymerization is the recombining of broken hydrocarbon chains into longer ones. MS-05 Page 48 Rev. 0