ENVIRONMENTAL AND SAFETY ASPECTS OF OSIRIS - A HEAVY-ION BEAM DRIVEN IFE REACTOR

A detailed safety analysis was performed for the inertial confinement fusion reactor OSIRIS. The radioactivity induced in the carbon fabric chamber concrete shield and Flibe breeder is very low allowing for their disposal at the end of the reactor life as Class A low level waste (LLW). The biological dose rate after shutdown behind the reactor biological shield shield is very low (0.11-mu-mrem/hr) allowing only for hands-on maintenance. A total of 91.5 Ci/day are routinely released to the environment producing an off-site dose to the maximally exposed individual (MEI) of 2.43 mrem/yr at the reactor site boundary. Only a small fraction (0.2%) of the reactor first wall would be mobilized during a loss of coolant/loss of flow accident. The decay heat generated in the concrete shield is very low such that its temperature would only increase by less than 2 degrees during such an accident. OSIRIS contains 660 tonnes of liquid Flibe as a coolant and breeder. A severe accident including a breach of the reactor building and chamber is estimated to release less than 0.5 kg of the activated Flibe to the environment. The total whole body (WB) early dose at the reactor site boundary during a pessimistic accident that includes the potential release of radioactive products from the chamber, shield and Flibe coolant would amount to 13.5 mrem. In addition, a 100% release of all the tritium steady state inventory (12.7 gm) inside the reactor building during operation would result in an additional 114 mrem of off-site dose. The total of 128 mrem off-site dose produced from OSIRIS eliminates the need for using N-stamp nuclear grade components in the reactor.