Nuclear Analysis of the First Wall/Blanket/Shielld of Inertial Fusion Energy Reactors

The design of the cavity and shielding system of the Prometheus reactors was undertaken by UCLA in conjunction with an IFE conceptual reactor study led by McDonnell Douglas. A wetted wall by a thin lead film was used as part of the first wall system (FWS) designated to protect the cavity against the microexplosions. The FWS is attached to the blanket/reflector/plena (B/R/P) system. For low activation consideration, Sic was used as the structural material and low pressure helium (1.5 MPa) was chosen as the coolant in the L i20 B/R/P system. In this paper, the results of the neutronics parametric study that led to the baseline design of the EWS and B/R/P system are given. The attenuation characteristics of two types of shielding materials were studied, namely, reinforced concrete and low-activation Pb/B4C composite. The latter was chosen as the bulk and beamlines shield due to its low act iv at i o n .