Nuclear reactor buildings

Purpose: To reduce the amount of radioactive materials released to the circumstances upon occurrence of reactor meltdown accidents. Constitution: Radioactive material-retaining layers are disposed in the annular gap formed between the outer wall of a reactor container and the inner wall of concretes of reactor buildings. In the thus constituted nuclear reactor buildings, if large rupture accidents should occur in recycling lines, which are followed by reactor core meltdown accidents due to the failure of normal operation of safety systems, thus leading to the destruction of the reactor container, fiberous glass wools in the radioactive material-retaining layers disposed in the annular gap retain the radioactive materials to greatly reduce the amount of materials released to the circumstances. The materials used for the radioactive material-retaining layers are not restricted only to the fiberous glass wools and any other materials can be used so long as they are highly retaining material (such as sand, chacoal, etc.). (Horiuchi, T.)