Criticality safety studies of a proposed uranium-zirconium alloy fuel fabrication facility

The purpose of the project described in this paper is to provide criticality limits and guidance for the initial planning phase of a new facility for the production of a new metal alloy fuel material for the Hanford N reactor. The proposed fuel material composition is a uranium-zirconium alloy consisting of ∼90.7 wt% zirconium and 9.3 wt% uranium. While the anticipated enrichments range from 55 to 70 wt% 235U, this analysis considers only 100 wt% 235U for simplicity and conservatism. The fuel material would be produced in the form of a solid, as-cast double billet using an arc-melt process. Two finished billets result from one as-cast double billet. The results of these studies indicate that the proposed production facility can be operated safely as long as the proper physical constraints and administrative criticality controls are implemented