In nuclear-weapon development, the main problem is securing sufficient weapons-grade material; it is particularly difficult to acquire fissile isotopes of uranium-235 (235U) or 239Pu. Weapons-grade uranium requires mining, extracting and enriching natural ore. Plutonium can be "bred" in reactors fueled by unenriched uranium, which requires chemical separation of the 239Pu produced.
Heavy water has been demonstrated as an effective moderator for 239Pu production, and may be separated from ordinary water by electrolysis.....
是的, 德國離製造還遠, 基本材料都收集不齊
