Safety issues of beryllium use in IFE power plants

Selection of materials for inertial fusion energy (IFE) power plant designs must consider a wide variety of factors such as performance, cost, ease of fabrication and safety and environmental (S&E) issues. In the past, we have performed an S&E assessment of mercury and lead as potential hohlraum materials, including for the first time a comparative analysis of the radiological and toxicological consequences of an accidental release. It was found that the chemical safety requirements dominate over radiological considerations. In the present work, we address the various safety issues regarding the use of beryllium in an IFE power plant. Beryllium is one of the constituents of the molten salt flibe (Li₂BeF₄), used in some IFE liquid-wall chamber concepts and also proposed as a candidate material in some target designs. Here, we want to assess the safety hazards of beryllium use in IFE, from both the radiological and the chemical toxicity points of view. For that purpose, we use the latest DOE regulations to compare potential accident scenarios with the Be concentration limits for public protection, to estimate the level of compliance of the safety standards. We also evaluate the effects from acute radiological and toxicological Be exposures. The results from this work demonstrate that whereas traditional IFE safety analyses have focused on radiological issues, chemical hazards must also be considered to provide a complete safety assessment for fusion power plants.