Plant Safety:Nuclear Criticality Safety Control
Plant safety is secured by nuclear criticality control
for safe handling of uranium.
- For safe handling of uranium to prevent nuclear criticality,
nuclear criticality safety control is implemented. - As methods of criticality control, so-called geometry control
and mass control are applied. - For well understanding of nuclear criticality safety control by employees,
periodical education is conducted.
Geometry Control:

Geometry of uranium handling components are designed so as to physically prevent nuclear criticality. The figure shows as one example, a ADU(ammonium diuranate) precipitation tank and its diameter designed not greater than limited value.
Mass Control:

The mass of uranium handled as one batch is limited to prevent nuclear criticality. The limited value of mass is chosen to less than a half of minimum critical mass.