Siemens-Unterrichts-Reaktor; a reactorSystem used to initiate, maintain and control a fission chai... with a permanent power of 100 milliwatt built by Siemens for training purposes. The SUR-100 is a homogenous reactorSystem used to initiate, maintain and control a fission chai...; the corePart of the nuclear reactor where the fission chain reaction... consist of a mixture of uraniumNatural radioactive element with the atomic number 92. The n... enriched to 20% and polyethylene.