[en] In 1998 fiscal year, a fussy program capable of calculating optimum combination ratio of raw materials in material design and a data library to use for the program were finished. And, verification of this program was carried out by comparison with composition of actual shielding materials and so forth. Optimization of hardening method was investigated by testing hardening ratio, hardness and so forth, or shape observation using electron microscope on combination of some shielding materials of three kinds of mono-functional monomers. In addition, a method to make better dispersing state of the materials was investigated by oligomerization of the monomers through electron beam irradiation. For evaluation of the materials, together with experimental investigation on forming rate of hydrogen gas accompanied with temperature change of high performance shielding materials and on component and forming rate of the other forming gas, precise density measurement and composition analysis were carried out. (G.K.)