Il Mantello - a helium cooled solid breeder blanket for NET

A report is given on the completion of ''II Mantello'', an engineering design study of a helium cooled, ceramic breeder blanket for NET. Aiming at improving the nuclear performance of the reference configuration, a design variant has been introduced that is based on the use of a ''mixed'' breeding moderator material (Be and γLiAlO2 separated by a thin steel sheath). The problems of assembly and operation of such blanket modules, within an outboard sector of the closed box structure envisaged for the NET first wall, have been thoroughly investigated. The main conclusions of the study, together with the consequent implications and guidelines for future blanket design work to be performed at ENEA-Frascati, are discussed. (author)