Accumulation and Transmutation of Spallation Products in the Target of Accelerator-Driven System

Analysis of the radiological burden of the spallation products (SP) was performed for various spallation targets (lead, tungsten, tin). The radiological burden was discussed in terms of toxicity based upon the concept of Annual Limit on Intake (ALI) shows that alpha-emitting rare earths (¹⁴⁶Sm, ¹⁴⁸Gd, ¹⁵⁰Gd, ¹⁵⁴Dy) are dominant. Their toxicity was estimated at equilibrium state with and without their transmutation. It is concluded that, in terms of toxicity, accumulation of SP in the target is quite comparable with transmutation of fission products (FP) in the blanket of Accelerator-Driven System (ADS).